Flow Studies for 

Recycling Metal Commodities 

in the United States 

Edited by Scott F. Sibley 

Circular 1196–A–M 

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary 

U.S. Geological Survey

Charles G. Groat, Director 

U.S. Geological Survey, Reston, Virginia : 2004 

For product and ordering information:


World Wide Web: http://www.usgs.gov/pubprod


Telephone: 1-888-ASK-USGS


For more information about the USGS:


World Wide Web: http://www.usgs.gov/


Telephone: 1-888-ASK-USGS


Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply


endorsement by the U.S. Government.


Library of Congress Cataloging-in-Publication Data 

Flow studies for recycling metal commodities in the United States / edited by Scott F. Sibley. 

p. cm. 

"Circular 1196-A-M"


Includes bibliographic references.


1. Scrap metals—Recycling—United States I. Sibley, Scott F. II. Geological Survey (U.S.)


TS214.F57 2003 

338.2—dc22 

2003049319 

ISBN 0-607-97344-7
iii 

Foreword 

As world population increases and the world economy expands, so does the demand for natural resources. An accurate assessment of the Nation’s mineral resources must include not only 

the resources available in the ground but also those that become available through recycling. 

Supplying this information to decisionmakers is an essential part of the USGS commitment to 

providing the science that society needs to meet natural resource and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and disseminate data 

on the domestic and international supply of and demand for minerals essential to the U.S. 

economy and national security. This information on mineral occurrence, production, use, and 

recycling helps policymakers manage resources wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the United States,” 

presents the results of flow studies for recycling 26 metal commodities, from aluminum to zinc. 

These metals are a key component of the U.S. economy. Overall, recycling accounts for more 

than half of the U.S. metal supply by weight and roughly 40 percent by value. 

Charles G. Groat 

Director 
v 

Contents 

[Letters designate the chapters] 

Foreword 

A.	 Gold Recycling in the United States in 1998

By Earle B. Amey


B.	 Platinum Recycling in the United States in 1998

By Henry E. Hilliard


C.	 Chromium Recycling in the United States in 1998

By John F. Papp


D.	 Zinc Recycling in the United States in 1998

By Jozef Plachy


E.	 Magnesium Recycling in the United States in 1998

By Deborah A. Kramer


F.	 Lead Recycling in the United States in 1998

By Gerald R. Smith


G.	 Iron and Steel Recycling in the United States in 1998

By Michael D. Fenton


H.	 Manganese Recycling in the United States in 1998

By Thomas S. Jones


I.	 Columbium (Niobium) Recycling in the United States in 1998

By Larry D. Cunningham


J.	 Tantalum Recycling in the United States in 1998

By Larry D. Cunningham


K.	 Tin Recycling in the United States in 1998

By James F. Carlin, Jr.


L.	 Molybdenum Recycling in the United States in 1998

By John W. Blossom


M. Cobalt Recycling in the United States in 1998 

By Kim B. Shedd 
U.S. Department of the Interior

U.S. Geological Survey

Gold Recycling in the United States in 1998 

By Earle B. Amey 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–A

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES

III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Global Geologic Occurrence of Gold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Gold Production Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Gold Market Prices and Use Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Gold Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Sources of Gold Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Old Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Disposition of Gold Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Infrastructure of Gold Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Scrap Collection Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Trade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Processing of Gold Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FIGURES


1. Flow diagram showing U.S. gold materials flow in 1998 . . . . . . . . . . . . . . . . . . . . A2 

2. Graph showing U.S. gold consumption by end-use sector


from 1978 through 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

TABLE


1. Salient statistics for U.S. gold scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A3
CONTENTS V 

CONVERSION FACTORS 

Most measurements in this report are in metric units, but troy ounces are used in some 

discussions because international gold prices are reported per troy ounce. Conversion 

factors are provided below. 

Multiply By To obtain 

Length 

meter (m) 3.281 foot 

Mass 

gram (g) 0.03527 ounce avoirdupois 

kilogram (kg) 2.205 pound avoirdupois 

kilogram (kg) 32.1507 troy ounce 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

troy ounce (troy oz) 31.10 gram 

Other 

gram per metric ton (g/t) 0.0292 troy ounce per short ton 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Gold Recycling in the United States in 1998 

By Earle B. Amey 

ABSTRACT 

In 1998, 175 metric tons (t) of refined gold was recovered by U.S. refiners from old and new scrap. The overall 

recycling rate was 29 percent when scrap consumption was 

compared with apparent domestic supply. Sources of old 

scrap included discarded jewelry, dental materials, plating 

solutions, and electronic equipment. A very high old scrap 

recycling efficiency of 96 percent was reached in 1998, the 

supply of old scrap peaked, gold prices were at an 18-year 

low, and substantial amounts of old scrap were exported. 

U.S. net exports of old scrap had a gold content of 28 t. 

INTRODUCTION 

This report describes trends in consumption, loss, and 

recycling of gold-containing materials in the United States 

in 1998, as depicted in the U.S. gold materials flow diagram 

(fig. 1). The purpose of the materials flow study was to illustrate the extent to which gold was being recycled and to 

identify recycling trends. 

Because of its high value, gold has been recycled 

through the ages. Modern jewelry that incorporates recycled 

gold could contain atoms of gold from an earring worn by 

Helen of Troy or a nugget of gold used in the 4th millennium 

B.C. to barter for ingots of crude copper at a Mediterranean

seaport. Gold’s high recycling rate is further illustrated by the 

fact that most of the gold ever mined can be accounted for 

(Lucas, 1993). Of an estimated 125,000 metric tons (t) of 

gold mined from historical times through 1998, only about 

15 percent is thought to have been lost or used in dissipative 

industrial processes or to be otherwise unaccounted for or 

unrecoverable. Of the remaining 106,000 t, an estimated 

34,000 t is in official stocks held by central banks, and about 

72,000 t is privately held as coin, bullion, and jewelry (Amey, 

1999). The total amount of gold ever mined is equivalent in 

volume to an 18-meter cube (Green, 1993, p. 4). 

It has been said that gold is forever; its high intrinsic and 

monetary value dictates that, in time, most of it will be recycled. In 1998, 175 t of refined gold was recovered by domestic refiners from old and new scrap. The value of this refined 

gold was about $1.7 billion, when it was calculated on the 

basis of the average gold price for 1998 of $295.24 per troy 

ounce (see appendix). The overall recycling rate was 29 percent when scrap consumption was compared with apparent 

domestic supply (table 1). This percentage is on the low side 

of the range of 20–70 percent estimated for gold recycling 

during the past 50 years. Gold recycling, however, cannot be 

viewed strictly from the U.S. market. International political 

and economic events that may influence the gold commodity market may be outweighed by developments perceived to 

favor gold as a medium of exchange. 

In 1998, secondary unrefined gold-bearing materials 

valued by the U.S. Census Bureau in excess of $370 million 

were exported, principally for refining to commercial-grade 

gold bullion. These materials are designated in figure 1 as old 

scrap exported, which had a gold content of 40 t. The principal recipient nations were Canada and the United Kingdom. 

Old scrap imported by domestic refiners during 1998, and 

originating in Canada, the Dominican Republic, Mexico, and 

elsewhere, had a gold content of 12 t and was valued at over 

$100 million. Thus, the value of the 28 t of gold in net 

exports of old scrap in 1998 was about $270 million. 

GLOBAL GEOLOGIC OCCURRENCE OF GOLD 

Estimates of gold’s abundance in the Earth’s crust 

range from 3 to 4 parts per billion (ppb) gold (Lucas, 

1985). This abundance is equivalent to about 1 gram of 

gold in 300 t of rock. Although data were sparse, gold was 

more abundant in mafic than in felsic igneous rocks and in 

sandstone than in other sedimentary rocks. Much of the 

gold that has been mined came from quartz veins or from 

alluvial deposits in streams. As these easily accessible 

sources became increasingly rare, gold mining shifted to 

bulk ores of lesser grades. South Africa has about half of all 

world gold resources, and Brazil and the United States have 

about 10 percent each (Amey, 1999). If the South African 

deposits are considered to be paleoplacers, alluvial deposits 

account for somewhat more than half of the world’s gold 

resources (Simons and Prinz, 1973, p. 266). 

Native gold is fairly insoluble in almost all surficial 

environments and is unaffected during weathering and 

decomposition of rocks. Hence, it occurs in extremely 

small amounts in freshwater, about 0.03 ppb, and even less 

in seawater, 0.011 ppb (Simons and Prinz, 1973, p. 266). In 

environments where humic or other acids exist, gold can 

become soluble, forming nuggets when it precipitates. 

A1 
DOMESTIC SUPPLY OF 

PRIMARY AND SECONDARY GOLD DISTRIBUTION OF DOMESTIC GOLD SUPPLY 

Net release of stocks:

Imports:

Domestic refinery production:

Primary .....................282Secondary ............... 175

l

Processing losses:

Primary ......... 5Secondary .... 6

l

Earmarked gold*..310

Refined bullion ... 257Compounds ........... 6

Old scrapconsumed ..........130

Old scrap exported ...40

New (prompt) scrapconsumed ....... 45 

Old scrapunrecovered ... 8 

Old scrapsupply ...... 178

Old scrapimported ...12

Old scrap generated:

Jewelry ............... 131

Coins ........ 49

Goldproducts inchange ... +3 

Exports:

Refi l

Investment bullion............. 318

Fabrication:

Jewelry .................. 173Dental ........................ 4Coin sheet ............... 57

l 

Processinglosses .... 5 

Gold productsto U.S.market ... 177 

New (prompt)scrapgenerated ...... 45 

Dissipativeuses ....... 8 

Homescrap Home

scrap 

11 

12 

276

446

303 

130

40

8 

130

45 

166 

166 

169 

8 

177 

49 

5 

45 

45 

318276

431 

1,025

Tota ......................457 

Tota ......... 11

Industry ................ -7

 COMEX**.............-10

 Dept. of Treasury...10 

Total ................ 303

 Powder ..................13

Total .................276

 Electronics ............. 7 Dental .................... 3 Other .................... 25 

Total ................ 166 

reservoir, net

ned bul ion ...... 430

 Compounds ............... 1

Total .................... 431

Electronics ................. 9

 Other ....................... 33

Tota ................... 276

A2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

* Earmarked gold means the net flow of gold to the U.S. market from foreign stocks

held in the New York Federal Reserve Bank.

**COMEX indicates gold released from private sector stocks as reported by the Commodity Exchange

(COMEX) Division of the New York Mercantile Exchange. 

Figure 1. U.S. gold materials flow in 1998. Values are in metric tons of contained gold. Sources of data are described in the section titled “Sources of Gold Scrap.” 
GOLD RECYCLING IN THE UNITED STATES IN 1998 

Table 1. Salient statistics for U.S. gold scrap in 1998. 

[Values in metric tons of contained gold, unless otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 

Value of old scrap consumed . . . . . . . . $1.234 billion 

Recycling efficiency3 . . . . . . . . . . . . . . . . . 96 percent 

Supply4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 

Unrecovered5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

New scrap consumed6 . . . . . . . . . . . . . . . . . . . . . . . . . . 45 

New-to-old-scrap ratio7 . . . . . . . . . . . . . . . . . . . . . . 25:75 

Recycling rate8 . . . . . . . . . . . . . . . . . . . . . . . . . 29 percent 

U.S. net exports of scrap9 . . . . . . . . . . . . . . . . . . . . . . . 28 

Value of U.S. net exports of scrap . . . . . . . . . $272 million

1Gold content of products theoretically becoming obsolete in the 

United States in 1998. Dissipative uses were excluded. 

2Gold content of products that were recycled in 1998. 

3(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported plus any old scrap stock decrease or 

minus any old scrap stock increase). 

4Old scrap generated plus old scrap imported. 

5Old scrap supply minus old scrap consumed minus old scrap 

exported minus old scrap stock increase. 

6Including prompt industrial scrap but excluding home scrap. 

7Ratio of quantities consumed, in percent. 

8Fraction of the gold apparent supply that is scrap on an annual basis. 

It is defined as (consumption of old scrap plus consumption of new scrap) 

divided by apparent supply (see appendix), measured in weight and 

expressed as a percentage. 

9Trade in scrap is assumed to be principally in old scrap. Net exports 

are exports of old scrap minus imports of old scrap. 

GOLD PRODUCTION PROCESSES 

Gold ores can be classified into two groups: (1) free 

milling ores from which native gold is recovered by crushing, 

gravity separation, amalgamation, and leaching processes, 

such as cyanidation, and (2) refractory ores, such as tellurides 

and other auriferous sulfides, that yield gold after complex 

oxidizing processes (Roskill Information Services, 1995, p. 

1). Many gold mining operations recover gold from cyanide 

leach solutions by precipitation with carbon in the pulp. The 

activated carbon collects gold from the cyanided pulp until 

the pulp contains 300 to 400 troy ounces of gold per metric 

ton of carbon. Gold with accompanying silver is desorbed or 

stripped from the carbon with a strong alkaline cyanide-alcohol solution. The precious metals are recovered from the strip 

solutions by electrodeposition on a stainless-steel-wool cathode. The cathode deposit is refined into a doré, a gold-silver 

bullion of variable composition, which is sent to a refiner. 

Gold is refined by chlorination in the molten state (Miller 

process) and by electrolysis (Wohlwill process). Generally, 

gold bullion made by the Miller process is 996 to 997 fine 

A3 

(99.6 to 99.7 percent), and bullion made by the Wohlwill 

process is 999.5 to 999.8 fine (99.95 to 99.98 percent) (Lucas, 

1985). Gold purity is expressed as fineness in parts per thousand or, in the case of gold alloys, in karats (parts per 24). 

When gold is associated with copper ores, it travels with 

the base metal through concentration and smelting to the 

refining stage. It is eventually separated from the anode 

slimes, which accumulate in electrolytic copper refiring 

cells, and is recovered as gold bullion in the precious-metals 

refinery (Lucas, 1985). 

GOLD MARKET PRICES AND USE PATTERNS 

The dollar price for gold decreased throughout 1998. The 

Engelhard Corporation’s industries quotation (listed weekly 

in Platt’s Metals Week) showed that the daily price of gold 

ranged from a low of nearly $275 per troy ounce on August 

28, 1998, to a high of about $314 on April 24. The average for 

the year was, to the nearest dollar, $295. The 1997 prices 

ranged from about $298 to $368 and averaged $332 per troy 

ounce (Amey, 2000, p. 33.1). 

In 1998, estimated uses of gold were jewelry, which 

includes arts, 63 percent; coins, 21 percent; industrial, which 

includes electronics and other assorted uses, 15 percent; and 

dental, 1 percent. U.S. gold-use patterns in 1998 were similar 

to those of the rest of the world (Murray and others, 1998, p. 

5). U.S. gold consumption by end-use sector from 1978 

through 1998 is depicted in figure 2. Two significant factors 

increased gold use: (1) the popularity of the American Eagle 

gold coin produced by the U.S. Mint since 1987 and (2) seven 

consecutive years (1992–98) of growth in unit sales for gold 

jewelry in the United States. Much of the latter increase came 

from outside the Northeast sector, which has been the traditional heartland of the U.S. jewelry industry. 

GOLD STATISTICS 

Various components of the U.S. gold materials flow were 

studied to specify the factors affecting recycling and to identify the ultimate direction and disposition of domestic supply. 

Companies that supply gold to end users were regularly contacted by the U.S. Geological Survey (USGS) to update data 

used to estimate the total amount of gold consumed by industry. Because new suppliers become active every year, the estimates were slightly understated but were still accurate to two 

significant figures. Most of the data used in this report relating to production, supply, and consumption of gold were 

obtained from USGS publications on minerals. Most of the 

remaining data were obtained from company reports and 

industry publications. 

SOURCES OF GOLD SCRAP 

Sources of old scrap and new scrap are key features of 

the U.S. gold materials flow diagram (fig. 1). Statistical 

data for domestic consumption of new and old scrap in 
A4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

300


250


200


150


100


50


0


1978 1983 1988 1993 1998


YEAR


End-Use Sector 

Coins 

Dental 

Industrial 

Jewelry 

Figure 2. U.S. gold consumption by end-use sector from 1978 through 1998. Values are in metric tons of contained gold. Industrial CONSUMPTION, IN METRIC TONS 

uses include the manufacture of electronic devices. 

1998 were collected by the USGS as a single quantity. The 

amount of new scrap was calculated by estimating that it 

generally is about 17 percent of the total input for the fabrication process. Gold coin cuttings, which became new 

scrap, were estimated to be 14 percent of the total input. 

Consequently, the amount of old scrap consumed may be 

obtained by subtracting the amount of new scrap consumed 

from the total scrap consumed. 

Figure 1 shows that the domestic supply of primary 

and secondary gold consists of (1) inputs from domestic 

refinery production, (2) imports, and (3) the net release of 

gold stocks from foreign countries, U.S. industry, the U.S. 

Department of the Treasury, and the private sector. Statistical data for domestic refinery production were collected by 

the USGS as primary and secondary quantities. Statistical 

data for gold imports were collected by the U.S. Census 

Bureau (written commun.). Statistical data for the net 

release of gold to the U.S. market from foreign stocks were 

reported by the New York Federal Reserve Bank (written 

commun.); data on industry stocks were collected by the 

USGS; Government stocks were reported in the Federal 

Reserve Bulletin (1999); and private sector stocks were 

reported by the Commodity Exchange (COMEX) Division 

of the New York Mercantile Exchange (CRU International, 

Ltd., 1999). 

Refined bullion, compounds, and powder were exported, bought as investments, or made into jewelry, electronic 

components, coins, and other products. More than 99 percent of the gold bullion coins were American Eagle coins, 

which were purchased at precious-metal dealers, brokerage 

companies, coin dealers, and participating banks strictly for 

investment. Coins are treated separately from other fabricated gold products in figure 1 to show the amount of gold 

held for investment purposes in 1998. Statistical data for 

coins were collected by the U.S. Mint (Shirley Jones-Keller, 

written commun., 1999); for gold exports, by the U.S. Census Bureau (written commun.); and for jewelry, electronic 

components, and other products, by the USGS. Investment 

data were obtained by calculating what remained of the 

domestic gold supply after gold exports and fabricated gold 

products were deducted. 

Data discussed in the following sections are summarized in table 1. 

OLD SCRAP GENERATED 

Old scrap consists of gold-containing products that have 

been discarded after use or after becoming obsolete. The old 

scrap generated in 1998 had a gold content of 166 t. The 

amount of gold in old scrap consumed, 130 t, amounted to 

78 percent of the gold in old scrap generated and had a value 

of more than $1.23 billion. Net exports of old scrap had a 

gold content of 28 t. 

The old scrap component of the gold supply was perhaps the most difficult component to quantify. In many 

areas of the world, especially where the holding of gold 

was encouraged by tradition, secondary gold, especially 

that derived from relatively crude gold jewelry, changed 

hands both locally and internationally from purchasers to 

goldsmiths and back again to purchasers. This flow was 

often in response to variations in the gold price and usually could not be followed statistically. In addition, some old 

scrap was lost because, in practice, gold cannot be economically recovered from all manufactured products; 

recovery becomes increasingly difficult as gold-bearing 

electronic products become more miniaturized. 

NEW SCRAP 

New scrap is generated during manufacturing processes and, for the most part, remains the property of the manufacturers; it is continually recirculated. A considerable 
GOLD RECYCLING IN THE UNITED STATES IN 1998 

amount of scrap is generated in manufacturing operations, 

but, because of strict controls over waste materials in precious-metals plants, nearly all of this home-generated scrap 

can be recovered. In 1998, 45 t of new scrap was consumed, 

which was about 25 percent of the total scrap consumed. 

DISPOSITION OF GOLD SCRAP 

The feature generally attributed to the metals recycling 

industry—high volume of comparatively low value metal— 

is quite unlike that of gold. Gold recycling deals with relatively low volumes of very highly valued raw material. 

Therefore, proper handling, accountability, and security 

against loss and theft during generation, collection, and distribution are important additional burdens not shared by 

most other metals industries. Many gold consumers have 

elaborate collection systems for reclaiming new gold scrap 

that results from the manufacture of gold products. Thus, 

there are very small losses. All materials that may come into 

contact with gold during the processing and handling are 

recycled. Gloves, aprons, and dust masks worn by gold 

workers and the dust, or sweeps, from the shops are collected and processed to get additional quantities of gold. At 

times, even the floors of the refineries are burned to recover 

gold. Similarly, a specialized field of secondary gold recovery gleans gold from defunct gold-processing operations 

(Lucas, 1993). 

The high intrinsic value of gold scrap shipped to a 

refiner dictates that special precautions be taken to assure 

preservation of the payable gold content. For example, raw 

electronic scrap may be collected, disassembled, or shredded, and gold components separated from other less valuable ones before shipping to a refiner (Lucas, 1993). At the 

higher end of the spectrum, gold scrap created during the 

manufacture of jewelry will go directly to the refiner. These 

are only a few examples of the scrap forms that typically 

cross a refiner’s loading dock. Each shipment can also be 

accompanied by documentation, ranging from title, insurance, and customs papers to licensing and transport documents that address local, State, and national environmental 

and other regulatory requirements. 

Each refining transaction is negotiated individually 

between the refiner and the customer. Ordinarily, refining 

schedules or outlines of services, capabilities, and charges 

are used by refiners to establish the basis upon which the 

negotiations will proceed (Lucas, 1993). Included in these 

negotiations are lot size and character of the product to be 

refined. Other factors may be minimum or standard treatment charges, charges for preparation and assaying, charges 

or penalties for the presence of deleterious elements, and 

instructions regarding the basis of payment. The customer 

may elect to sell the material outright, may have the scrap 

refined and the gold prepared to contract specifications and 

returned (toll refining), or may elect to draw an equivalent 

A5 

value of refined metal from a pool account established by 

the refiner. 

A shipment is assigned a control number upon arrival at 

the refinery, then is weighed, evaluated, and subjected to a 

variety of preparatory processes, depending upon the shipment’s character (Lucas, 1993). Preparation may include 

incineration, roasting or melting, and pulverizing, shredding, or grinding to produce a homogeneous product. At this 

point, one or more representative samples are drawn so that 

assays can determine the character and content of the original shipment. The refiner may combine similar lots to form 

large batches. These batches are sent to the refining process, 

which may include pyrometallurgical, hydrometallurgical, 

and electrochemical processes to separate gold from associated impurities. 

OLD SCRAP RECYCLING EFFICIENCY 

Old scrap recycling efficiency shows the relation 

between what was theoretically available for recycling and 

what was not recovered. This relation is defined as (old 

scrap consumed + old scrap exported) divided by (old scrap 

generated + old scrap imported ± scrap stock changes), 

measured in weight and expressed as a percentage. The old 

scrap generated in 1998 was made up of jewelry and art 

products, industrial and electronic scrap, and dental debris. 

The typical content of gold in electronic scrap was about 

300–400 grams per metric ton (ASM International, 1998, p. 

1192). Most old scrap came from jewelry and electronic 

manufacturers’ buy-back programs. A very high old scrap 

recycling efficiency of 96 percent was reached in 1998, the 

supply of old gold scrap peaked, gold prices were at an 18­

year low, and substantial amounts of old gold scrap were 

exported. 

INFRASTRUCTURE OF GOLD SCRAP 

The historical and universal recognition of gold as a 

highly valuable commodity assures that virtually every conceivable recycling method will be used to recapture it from 

scrapped materials. Industrial gold consumers, the principal 

sources of supply, keep their gold-bearing scrap moving 

into the market on an established, routine basis for security 

reasons. On the other hand, private individuals may hoard or 

sell gold in response to the prevailing or anticipated economic or political climate. For example, a person may hoard 

gold coins, bars, and jewelry as a hedge against inflation or 

in anticipation of economic or political upheaval and may 

sell gold coins, bars, and jewelry in times of relative stability when alternative, dividend-paying investments may be 

more attractive. Most of the conditions and incentives that 

have encouraged high rates of gold recycling exist today and 

will probably exist in the future. Gold, more than any other 

recyclable material, continues to be a highly sought after 

commodity in the secondary metals market. 
A6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

SCRAP COLLECTION SYSTEMS 

Refiners throughout the world recover secondary gold 

from scrap. In the United States in the past 20 years, as much 

as 70 percent and as little as 25 percent of the scrap came 

from current manufacturing operations, and the remainder 

came from old scrap, such as discarded jewelry, dental materials, used plating solutions, and junked electronic equipment. A few dozen companies, out of several thousand companies and artisans, dominated the fabrication of gold into 

commercial products. Most of the domestic scrap was 

processed by refiners centered in the New York, N.Y., and 

Providence, R.I., areas. Other centers were in California, 

Florida, and Texas, although the trend in 1998 seemed to be 

toward a less centralized industry. Scrap dealers processed 

the scrap and then shipped the upgraded product to refiners 

and fabricators for further treatment and refining. The U.S. 

Department of Defense (DOD) recovered significant quantities of gold from military scrap. Other Federal agencies 

either participated in the DOD recovery program or had their 

own; all of the scrap reclaimed through these programs was 

sent to refiners for further processing in 1998. 

Gold-bearing scrap was paid for on the basis of gold content, as determined by analytical tests. The market price for 

gold was paid on the day that the refined product was available for sale. Processing charges and adjustments for processing losses were deducted from the total value in settling 

payments. Aside from dealer-processors and refiners, there 

were no markets for scrap gold. The market is limited by the 

Federal Trade Commission requirement for karat identification of jewelry alloys, which in effect requires gold refiners to 

know the chemical analysis of the alloys they purchase and 

requires gold refiners to separate the constituents of scrap to 

assure meeting karat standards (Public Law 226, 1906). 

TRADE 

In 1998, U.S. exports of gold scrap decreased for the 

second straight year (to 40 t), after 5 years of increase, while 

imports increased for the second year in a row (to 12 t). As 

it had been for many years, the United States was still a net 

exporter of gold scrap. Prices for gold waste and scrap 

imported and exported in 1998 averaged $190 and $197 per 

troy ounce, respectively; the annual average price for gold 

was $295 per troy ounce. 

Exports of refined gold bullion were 430 t; the United 

Kingdom (209 t) was the principal destination, followed by 

Switzerland (79.6 t), Australia (47 t), and Canada (46.7 t). 

More than 8 percent of all gold exported was scrap. Imports 

for consumption of refined gold bullion in 1998 were 257 t; 

Canada (96.5 t) was the largest supplier, followed by Australia (62.4 t), Brazil (32.7 t), and Peru (23.1 t). More than 4 

percent of all gold imports were scrap. 

PROCESSING OF GOLD SCRAP 

Scrap metals can be processed by either primary or 

secondary refiners. The latter handle only scrap, such as 

discarded jewelry, electronics, and dentistry products. 

Other types of scrap include gold-bearing slimes, solutions, and sludges; precipitates from base (lead and zinc) 

or precious metals recycled from smelters and refiners; 

and old gold coins, medals, and previously hoarded lowpurity nonaccredited gold bars. Primary refiners receive 

doré directly from the mine in addition to gold scrap that 

has been amassed by collectors. Most refiners will not 

accept scrap lots of less than 0.5 t, and many have a 2.5-t 

minimum (Garino, 1994). Many small shipments are 

obtained from collection points throughout the Nation, 

and some even come from overseas. At the higher end of 

the spectrum of value, scrap generated during the manufacture of karat gold jewelry will go directly from the 

manufacturer to the smelter-refiner. Scrap originating at 

the jewelry manufacturer is closely monitored by the 

company from generation through collection, packaging, 

and transportation to the recovery plant. 

Upon arrival at the refinery, each shipment is assigned 

a control number. Each scrap shipment is accurately 

weighed, blended, and analyzed for precious-metal content 

before payment is made (Lucas, 1993). It is common for a 

representative of the source company to be present during 

this step. Once the refinery owns the scrap, impurities such 

as lead, copper, and silver are removed from the gold by a 

high-temperature chlorination step (Miller process). 

The purified scrap that remains after chlorination is 

electrorefined (Wohlwill process) to recover gold directly in 

what is called a fine gold cell. High-grade anodes are suspended from positive bus bars by platinum hooks, and the 

gold is plated out into thin sheets of pure gold called starting sheets. Gold produced in this manner is 999.75 fine or 

better. The sludge that remains in the cell contains platinumgroup metals, which can be recovered by various methods 

that are usually patented by individual companies for their 

own use. 

Products derived from secondary materials have a 

wide range of shapes and forms, including some bars of 

pure gold, sheet gold, wire, tubing, foils, leaf, casting 

grain, gold-plating solutions, gold-bearing organometallic 

liquids, and conductive inks and pastes. Probably the 

greatest loss in gold fabrication occurs in gold electroplating plants where fouled solutions (containing cyanides that 

must be labeled “toxic waste”) or depleted solutions are 

sometimes discarded (Recycling Today, 1990, p. 69). 

Likewise, some old scrap is lost, because, in practice, gold 

cannot be economically recovered from all manufactured 

products. 
GOLD RECYCLING IN THE UNITED STATES IN 1998 

OUTLOOK 

Barring any unforeseen changes in the established pattern of world secondary supply, the quantity of gold generated from secondary sources was forecast to be about the same 

in 1999 as it was in 1998 (Klapwijk and others, 1999, p. 7), 

which is more than 20 percent of the total world gold supplied to fabricators, investors, and exporters. Developments 

that may increase the percentage of scrap entering the market include the following: 

1.	 Any decline in world gold production, if not offset by 

refined supplies from other sources (such as central 

bank sales or bullion sales from the private sector), 

could lead to higher prices and thereby cause more 

material to enter the recycling stream. 

2.	 The establishment of more efficient, centralized scrap 

collection and recovery centers could encourage higher 

rates of recycling. 

3.	 Continued growth in the demand for gold jewelry in 

rapidly industrializing nations, such as those of the Far 

East and China, could result in increased recycling of 

older style jewelry as fashion tastes evolve with 

improved standards of living. 

REFERENCES CITED 

Amey, E.B., 1999, Gold: U.S. Geological Survey Mineral Commodity Summaries 1999, p. 74–75. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/mcs/1999/mcs99.pdf) 

_____2000, Gold, in Metals and minerals: U.S. Geological Survey 

Minerals Yearbook 1998, v. 1, p. 33.1–33.7. (Also available 

online at http://minerals.usgs.gov/minerals/pubs/commodity/gold/300498.pdf) 

A7 

ASM International, 1998, Recycling of precious metals from electronic scrap, in Metals handbook (2d ed.): Materials Park, 

Ohio, ASM International, p. 1185–1195. 

CRU International, Ltd., 1999, Gold quarterly industry and market 

outlook: London, CRU International, Ltd., June, p. 5–11. 

Federal Reserve Bulletin, 1999, Table 3.12, U.S. reserve assets, in 

Financial and business statistics: Federal Reserve Bulletin, v. 

85, no. 4, p. A51. 

Garino, R.J., 1994, Commodities, scrap recovery changing: Institute of Scrap Recycling Industries Report, no. 94–9, May 5, 

2 p. 

Green, Timothy, 1993, The world of gold: London, Rosendale 

Press, 388 p. 

Klapwijk, Philip, le Roux, Hester, Walker, Paul, and Newman, 

Paul, 1999, Gold 1999: London, Gold Fields Mineral Services Limited, 113 p. 

Lucas, J.M., 1985, Gold, in Mineral facts and problems: U.S. 

Bureau of Mines Bulletin 675, p. 323–337. 

———1993, Gold, in Recycled metals in the United States: Washington, D.C., U.S. Bureau of Mines Special Publication, 

October, p. 23–25. 

Murray, Stewart, Klapwijk, Philip, le Roux, Hester, and Walker, 

Paul, 1998, Gold 1998: London, Gold Fields Mineral Services Limited, 64 p. 

Recycling Today, 1990, Precious-metals recycling confronted by 

regulations: Recycling Today, v. 28, no. 1, January, 108 p. 

Roskill Information Services, 1995, Gold—Market update, analysis, and outlook: London, Roskill Information Services, 

150 p. 

Simons, F.S., and Prinz, W.C., 1973, Gold, in Brobst, D.A., and 

Pratt, W.P., eds., United States mineral resources: U.S. Geological Survey Professional Paper 820, p. 263–275. 
A8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

APPENDIX—DEFINITIONS 

apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizer, making it exceptionally difficult and costly to recycle. 

doré. A gold-silver bullion of variable composition. 

gold bullion. Refined gold in the shape of bars or ingots. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new 

scrap are borings, castings, clippings, drosses, skims, 

and turnings. New scrap includes scrap generated at 

facilities that consume old scrap. Included as new 

scrap is prompt industrial scrap—scrap obtained from 

a facility separate from the recycling refiner, smelter, 

or processor. Excluded from new scrap is home scrap 

that is generated as process scrap and used in the same 

plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal 

articles that have been discarded after serving a useful purpose. Typical examples of old scrap are electrical wiring, lead-acid batteries, silver from photographic materials, metals from shredded cars and 

appliances, used aluminum beverage cans, spent catalysts, and tool bits. This is also referred to as postconsumer scrap and may originate from industry or 

the general public. Expended or obsolete materials 

used dissipatively, such as paints and fertilizer, are 

not included. 

old scrap generated. Gold content of products theoretically becoming obsolete in the United States in the year 

of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) + exports of old scrap (OSE)) divided by 

(old scrap generated (OSG) plus imports of old scrap 

(OSI) plus a decrease in old scrap stocks (OSS) or 

minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

price. Based on the unit value of gold in materials. Values 

of gold in this report are calculated on the basis of the 

average gold price for 1998 of $295.24 per troy ounce. 

Daily prices that were averaged came from the Engelhard Corporation’s industries quotation (listed weekly 

in Platt’s Metals Week). 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even recovery of a metal where it is not desired but 

can be tolerated—such as tin from tinplate scrap that is 

incorporated in small quantities (and accepted) in some 

steels only because the cost of removing it from tinplate 

scrap is too high and (or) tin stripping plants are too 

few. In all cases, what is consumed is the recoverable 

metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 
U.S. Department of the Interior

U.S. Geological Survey

Platinum Recycling in the United States in 1998 

By Henry E. Hilliard 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–B

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Sources of PGM Ore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Russia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Sources of Platinum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Old Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Automobile Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Reforming Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Chemical-Process Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Home Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Disposition of Platinum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Scrap Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Unrecovered Old Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Infrastructure of Platinum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Scrap Collection Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Trade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Processing of Platinum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

FIGURES 

1. Flow diagram showing U.S. platinum materials flow in 1998 . . . . . . . . . . . . . . . . . B2

2. Graph showing U.S. platinum consumption by end-use sector from 1978 to 1998 . . . 4

TABLE 

1. Salient statistics for U.S. platinum scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . B3 
CONTENTS V 

CONVERSION FACTORS 

Most measurements in this report are in metric units, but a few terms are in customary units. 

Conversion factors are provided below. 

Multiply By To obtain 

kilometer (km) 

inch (in.) 

Length 

0.6214 

25.4 

mile 

millimeter 

Volume 

cubic foot (ft3

) 0.02832 cubic meter 

Mass 

microgram (μg) 

gram (g) 

kilogram (kg) 

kilogram (kg) 

metric ton (t, 1,000 kg) 

troy ounce (troy oz) 

0.00000003527 

0.03527 

2.205 

32.1507 

1.102 

31.10 

ounce avoirdupois 

ounce avoirdupois 

pound avoirdupois 

troy ounce 

short ton (2,000 pounds) 

gram 

Pressure 

kilopascal (kPa) 

kilopascal (kPa) 

0.1450 

0.009869 

pound force per square inch 

1 atmosphere 

Other 

gram per metric ton (g/t) 0.0292 troy ounce per short ton 

For temperature conversions from degrees Celsius (°C) to degrees Fahrenheit (°F), use the following: 

°F = (1.8 × °C) + 32 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Platinum Recycling in the United States in 1998 

By Henry E. Hilliard 

ABSTRACT 

In the United States, catalytic converters are the 

major source of secondary platinum for recycling; about 

25,500 kilograms of platinum-group metals from automobile catalysts was available for recycling in 1998. Other 

sources of platinum scrap include reforming and chemical-process catalysts. The glass industry is a small but significant source of platinum scrap. In 1998, an estimated 

7,690 kilograms of platinum was recycled in the United 

States. The U.S. recycling efficiency for old scrap was 

calculated to have been 76 percent in 1998; the recycling 

rate was estimated at 16 percent. 

INTRODUCTION 

World resources of platinum appear ample for the foreseeable future. Political and economic events in the past 

decade, however, have raised concerns about the availability 

and reliability of the supply of platinum and other metals in 

this group. This report discusses the 1998 flow of platinum 

in the United States from mining, through metallurgical and 

chemical applications, to recycling (fig. 1, table 1). Factors 

influencing the rate and availability of material for recycling 

are described, especially areas where significant losses 

occurred. 

Platinum-bearing scrap is a heterogeneous material that 

may also contain one or more of the other platinum-group 

metals. This report deals primarily with platinum, which was 

the most valuable and abundant platinum-group metal 

(PGM) found in scrap materials at the time of this study. The 

annual recycling rate for platinum, which represents the fraction of the metal’s apparent supply that is scrap, was estimated at 16 percent in 1998. The balance of apparent supply 

was primary platinum (see appendix). This study also indicates that materials containing about 8,500 kilograms (kg) of 

platinum were unrecovered in 1998, representing about 14 

percent of U.S. apparent consumption. 

Six elements of group VIII in the periodic table of the 

elements have been collectively designated the platinumgroup metals; they are palladium (Pd), platinum (Pt), iridium 

(Ir), osmium (Os), rhodium (Rh), and ruthenium (Ru). 

Sometimes called noble metals because of their resistance to 

oxidation, these precious metals are found in the Earth’s 

crust in very low concentrations. PGM’s are conveniently 

separated into two subgroups; the light PGM’s (those of 

lower atomic weight) are Ru, Rh, and Pd, and the heavy 

PGM’s are Os, Ir, and Pt. 

The PGM’s are strongly siderophilic and chalcophilic; 

that is, they occur predominantly as pure metals and alloys 

and, to a much lesser extent, combined with sulfur, tellurium, 

and arsenic. They occur in rock-forming silicates in small to 

negligible amounts. For the most part, PGM’s are concentrated in the early stages of magmatic differentiation and, 

consequently, are most abundant in magmatic mafic and 

ultramafic bodies and associated ore deposits. Under certain 

conditions, as yet imperfectly known, the PGM’s are carried 

through the differentiation process because of their lack of 

affinity for the silicate minerals and are then concentrated in 

the products of late hydrothermal solutions (Wright and 

Fleischer, 1965, p. A2). 

Despite their limited availability, these metals and 

chemical compounds containing them are extremely useful 

as catalysts in the automobile, chemical, and petroleum 

industries, as conductors in the electrical and electronic 

industries, in extrusion devices, in dental and medical prostheses, and in jewelry. Also, the glass industry takes advantage of platinum’s high melting point, its noncontaminating 

behavior, and its chemical inertness and resistance to corrosion in the manufacture of high-quality optical and special 

glasses. 

Platinum is primarily an industrial metal. There are, 

however, small quantities in the possession of speculators 

and investors. In 1998, there was strong demand for the platinum American Eagle coin, launched by the U.S. Mint in 

1997. Domestic and foreign sales of this coin totaled 5,443 

kg in 1998 (U.S. Mint, 1999, p. 7–13). Although Eagle coin 

sales were concentrated in the United States, the coin also 

found a market in Japan. Demand in Japan was mainly for 

smaller coins, weighing 0.10 or 0.25 troy ounce (troy oz), 

many of which were incorporated into watches and other 

items of jewelry. There are no reliable statistics available 

about the quantity of platinum held by speculators and 

investors. Probably stocks are held in banks and private holdings. This material, held for speculation and profitmaking, is 

B1 
DISTRIBUTION OF DOMESTIC SUPPLY OF

DOMESTIC SUPPLY OF PRIMARY PRIMARY AND SECONDARY PLATINUM

B2 

Government stockpileshipments of platinum . . . 4,510

Old scrapconsumed . . . . . 7,690

Old scrapexported . . . . 19,700 

Old scrap generated:

Automobile catalysts . . . . . . . 25,500

42,700 

Old scrapunrecovered . . 8,500 

Platinumproductsreservoirnet change

Exports of refined platinummetal, concentrates, ores,and coins . . . . . . . . . 15,000

Platinumproducts toU.S. market New scrap

generated . . . . 5,600 

118,000 

U.S. investment:

Platinum coins . . . . .4,520

Other . . . . . . . . . . . . . . 480

Platinum metal,prefabricated . . . . . . 10,000 

AND SECONDARY PLATINUM

Processing losses . . . . 20 

Dissipativeuses . . . . 4,000 

Old scrapsupply . . . . . . . 48,100

Old scrapimported . . . 5,390

Old scrap stockincrease at collection

4,510

97,300

16,500 

15,000

5,00010,000

88,300

10,000 82,700 

5,600 

4,000 

12,200 8,500

42,700 

7,690 

19,700

3,240

5,600 

7,690

20 

88,700 

Platinum metalfabrication . . . . 88,300

Domestic production of Ptin concentrates . . . . 3,240

Refinery production ofplatinum metal . . . . 16,500 

Home scrap 

Imports of platinum metal:

Unwrought . . . . . . 75,400 

42,700 

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES Chemical-process catalysts . . . 2,500 Reforming catalysts . . . . . . . . 14,700 Total . . . . . . . . . . . . . . . . . . . . +46,000 . . . . 92,700 Total . . . . . . . . . . 5,000 centers . . . . . .12,200 Prefabricated . . . . 10,200 Other . . . . . . . . . . . 11,700 Total . . . . . . . . . 97,300 

Figure 1. U.S. platinum materials flow in 1998. Values are in kilograms of contained platinum, and totals have been rounded to three significant figures. Sources of data aredescribed in the section titled “Sources of Platinum Scrap.” 
PLATINUM RECYCLING IN THE UNITED STATES IN 1998 B3


put on the market infrequently, depending upon price and 

price outlook. The material is usually of high purity and is 

not likely to be found in the recycling circuit, except as home 

scrap during its manufacture. 

SOURCES OF PGM ORE 

Canada, South Africa, Russia, and the United States 

account for nearly all of the world’s primary production of 

PGM ore. The relative amounts of the individual elements in 

ores vary from deposit to deposit and from country to country. The ratio of platinum to palladium in ores can vary from 

3:1 in the Bushveld Complex in South Africa to 1:3.5 in the 

Noril’sk deposit in Russia and 1:3 in the J-M Reef of the 

Stillwater Complex in the United States and the Sudbury 

Complex in Canada (Conradie, 1997). 

CANADA 

Small amounts of silver, gold, and PGM’s are present in 

most sulfide deposits of nickel. In Canada, PGM’s are mainly a byproduct of copper-nickel production. Most of the 

nickel ores are located in the Sudbury Complex in Ontario. 

The complex is a large stratiform, oval intrusion with dimensions along the axes of 50 and 23 kilometers (km). The copper-nickel deposits of the Sudbury area are peripherally 

located around the structure of an elliptical basin-shaped 

stratiform complex referred to as the Nickel Irruptive or the 

Sudbury Basin. The Nickel Irruptive consists of an outer part 

of noritic rocks and an inner part of granophyre (micropegmatite) (Cabri and Laflamme, 1976, p. 1159). The concentration of PGM’s averages about 0.9 to 1.0 gram per metric 

ton (g/t), with about 40 percent Pd, 40 percent Pt, and 20 percent Ir, Os, Rh, and Ru. Canada also produces nickel-copper 

ores with byproduct PGM’s from the entire spectrum of 

ultramafic and mafic complexes that occur in Manitoba, 

Ontario, and Quebec (Allen, 1960, p. 1–26; Page and others, 

1973; Sutphin and Page, 1986, p. 2–7). 

SOUTH AFRICA 

South Africa is the world’s largest source of platinum. 

South Africa’s PGM output is derived mostly from the 

Bushveld Complex, with only a small amount coming from 

the Evander Gold Field and the Phalaborwa Complex. Currently, 10 mines are producing platinum in the Bushveld 

Complex (South Africa Department of Minerals and Energy, Minerals Bureau, 1997, p. 34–40). Of these, nine 

exploit the Merensky Reef and UG2 Chromite Layer, and 

one, Potgietersrust Platinum Ltd., the only open-cast operation, exploits the Platreef on the northern limb of the complex. Eight of the mines are located on the western limb of 

the Bushveld Complex; Atok Mine, of Lebowa Platinum 

Mines Ltd., is currently the only producer on the eastern 

limb. Beneficiation of PGM ore through milling, flotation, 

and smelting (to form a matte containing PGM’s, gold, silver, and the base metals cobalt, copper, and nickel) is 

Table 1. Salient statistics for U.S. platinum scrap in 1998.


[Values in kilograms of contained platinum, unless otherwise specified]


Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42,700 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,690 

Value of old scrap consumed . . . . . . . . . . . $117 million

Recycling efficiency3 . . . . . . . . . . . . . . . . . . . 76 percent 

Supply4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48,100 

Unrecovered5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,500 

New scrap consumed6 . . . . . . . . . . . . . . . . . . . . . . . . . 5,600 

New-to-old-scrap ratio7 . . . . . . . . . . . . . . . . . . . . . . . . 42:58 

Recycling rate8 . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 percent 

U.S. net exports of scrap9 . . . . . . . . . . . . . . . . . . . . . . 14,310 

Value of U.S. net exports of scrap . . . . . . . . . . . $200 million

1Platinum content of products theoretically becoming obsolete in the 

United States in 1998. Net U.S. imports of semifinished products containing 

platinum in 1998 are included. Dissipative uses are excluded. 

2Platinum content of products that were recycled in 1998. 

3(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported plus any old scrap stock decrease or minus 

any old scrap stock increase). 

4Old scrap generated plus old scrap imported plus old scrap stock 

decrease. 

5Old scrap supply minus old scrap consumed minus old scrap exported 

minus old scrap stock increase. 

6Including prompt industrial scrap but excluding home scrap. 

7Ratio of quantities consumed, in percent. 

8Fraction of the metal apparent supply that is scrap, on an annual basis. 

9Trade in scrap is assumed to be principally in old scrap. Net exports 

are exports of old scrap minus imports of old scrap. 

undertaken at the various mines. Further refining of the 

matte, including extraction of the base metals and recovery 

of the precious metals, takes place at refineries near 

Rustenburg, Brakpan, and Springs. Some matte is sent to 

refineries outside the country for toll refining. In 1998, 

South Africa produced about 117,000 kg of platinum and 

57,300 kg of palladium (Hilliard, 2000b, p. 58.7). 

RUSSIA 

Probably more than 97 percent of Russia’s mine output 

of PGM’s is a byproduct of nickel-copper mining. The nickel-mining complex at Noril’sk, in northwestern Siberia, 

accounts for about 95 percent of total Russian production, 

and the mines at Pechenga on the Arctic coast account for 

most of the remainder. Modes of occurrence and composition of PGM’s in different types of ores vary significantly at 

Noril’sk. In disseminated ores, the main PGM minerals are 

represented by isoferroplatinum and cooperite, whereas in 

massive ores, very diverse palladium intermetallic compounds and tetraferroplatinum occur (Genkin and 

Evstigneeva, 1986, p. 1204). PGM’s are refined at the metallurgical complex in Krasnoyarsk, East Siberia. In 1998, 

Russia produced about 17,000 kg of platinum and 47,000 kg 

of palladium (Hilliard, 2000b, p. 58.7). 
B4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES


40


35


30


25


20


15


10


5 

0 

End-use sector 

Automobile catalysts 

Chemical-process catalysts 

Electrical and electronic industries 

Reforming catalysts 

Other 

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 

YEAR 

Figure 2. U.S. platinum consumption by end-use sector from 1978 to 1998. CONSUMPTION, IN THOUSANDS OF KILOGRAMS

UNITED STATES 

The Stillwater Mine near Nye, Mont., is the only primary PGM producer in the United States. The Stillwater 

Complex is an elongated assemblage of intrusive rocks that 

occurs in Sweetwater County, Mont., and extends into Park 

and Stillwater Counties. In its annual report, the Stillwater 

Mining Company reported its 1998 production as 10,575 kg 

of palladium and 3,235 kg of platinum (Stillwater Mining 

Company, 1999). In 1998, the company mined 653,184 metric tons (t) of ore. In conjunction with the operation of the 

mine, the average throughput at the mill facility was 1,196 

metric tons per operating day (t/d) with a recovery rate of 91 

percent. The mill head grade was 23.7 grams (g) of combined palladium and platinum per metric ton of ore. 

The Stillwater Mining Company operates a smelter and 

base-metals refinery (BMR) at the company’s metallurgical 

complex in Columbus, Mont. At the smelter, concentrate is 

treated to produce matte containing approximately 22.3 kg 

of palladium and platinum per metric ton. The matte is subsequently sent to the BMR, which produces a filter cake that 

is about 60 percent palladium and platinum. The filter cake 

is sent to metal refiners in New Jersey, California, and Germany, where it is converted into palladium and platinum 

sponge for sale to end users. 

In 1998, the Stillwater Mining Company restarted its 

program to process spent automobile catalysts for the recovery of PGM’s. In 1998, approximately 139 t was processed 

in the BMR at a rate of 1 t/d. The usual procedure was to 

blend spent catalysts with concentrate from the mill (Stillwater Mining Company, 1999). 

SOURCES OF PLATINUM SCRAP 

Typical sources of platinum for secondary refining 

include spent automobile, reforming, and chemical-process 

catalysts; electronic scrap; jewelry; and used equipment 

from the glass industry (fig. 2). Spent automobile catalysts 

have emerged as the major source of secondary platinum, 

palladium, and rhodium. In the United States, about 25,500 

kg of PGM’s from automobile catalysts was available for 

recycling in 1998 (see p. B5). 

OLD SCRAP GENERATED 

Old scrap generated is defined as the platinum content 

of products theoretically becoming obsolete in the United 

States in 1998. Total platinum old scrap generated in 1998 in 

the United States from automobile catalysts, reforming catalysts, and chemical-process catalysts was estimated as 

42,700 kg (table 1). Old scrap consumed, defined as the platinum content of products recycled, was estimated at about 18 

percent of old scrap generated or 7,690 kg. 

AUTOMOBILE CATALYSTS 

Spent automobile catalysts have emerged as the major 

source of secondary platinum, palladium, and rhodium. The 

amount of platinum that is recovered from automobile catalytic converters depends upon the following factors: (1) the 

average loading of platinum in the converters, which will not 

be a constant, (2) the probability that vehicles from each of 

the previous model years will be taken out of service in the 

year under consideration, (3) the percentage of the vehicles 

that are taken out of service in that year and are scrapped, 
PLATINUM RECYCLING IN THE UNITED STATES IN 1998 B5


and (4) the percentage of platinum that is recoverable from a 

used converter. The first of these factors can only be estimated, but industry-based statistics are available for the second 

factor. A value for the third factor depends upon the returns 

expected in the scrap market. Annual figures for automobiles 

scrapped are influenced by the strength or weakness of the 

scrap metal market. Thus, vehicles retired in years when the 

price of scrap is depressed may not reach the scrap yard until 

there is sufficient economic incentive. In the long run, however, it is likely that most vehicles withdrawn from service 

end up as scrap. As for the fourth factor, research has shown 

that the high recovery rates typical of PGM recycling in the 

chemical, petroleum, and electronic industries can also be 

achieved with automobile catalysts (Dhara, 1983). 

Beginning with the 1974 model year, new automobiles 

sold in the United States have been equipped with catalytic 

converters that chemically convert polluting substances in 

automobile exhaust to nontoxic materials. Automobile catalysts were developed to remove carbon monoxide (CO), 

hydrocarbons (HC), and the oxides of nitrogen (NOX) that 

cause air pollution from vehicle exhausts. Small amounts of 

platinum, either alone or combined with other PGM’s, were 

used to oxidize and reduce the exhaust gases, thereby significantly lowering harmful emission levels. 

The first catalytic converters used a monolithic system 

that incorporated palladium and platinum as the active constituents to oxidize the CO and HC. NOX was controlled by 

modifications to the engine. In addition to monoliths, highly 

porous pelleted materials were also used. All converters now 

use monolithic supports because of the monolith’s high geometrical surface area and low pressure drop during operation. 

Since the introduction of the basic catalytic converter in 

1974, the technology has advanced in response to tightening 

air-quality-control regulations; for example, the three-way 

oxidation-reduction converter (TWC) was developed. In the 

TWC system, all three pollutants—CO, HC, and NOX—are 

converted in one reactor using a platinum-rhodium catalyst 

coated on a ceramic monolith. Thus, a reducing-type catalyst, based on rhodium for the reduction of NOX, is combined with a conventional oxidation catalyst to provide 

three-way emission control of the pollutants. In TWC’s, the 

platinum-to-rhodium ratio is generally about 10:1. The 

amount of PGM’s used in the manufacture of these devices 

is more than the total amount consumed in all other U.S. uses 

combined (Roskill Information Services Ltd., 1991, p. 99). 

At the beginning of the 1980’s, General Motors suggested that a typical TWC might contain 1.555 g Pt, 0.622 g 

Pd, and 0.156 g Rh (Roskill Information Services Ltd., 1991, 

p. 100). The oxidizing units of early TWC’s are thought to 

have contained platinum and palladium in the ratio of 2:1. 

The palladium content subsequently has risen considerably. 

Newer TWC’s may contain about 1.8 kg (58 troy oz) PGM’s 

per cubic meter of monolith. A catalytic converter measuring 

10 centimeters (cm) in diameter by 15 cm in length would 

contain 2.3 g (0.074 troy oz) PGM’s. A typical mean level of 

1.5 g (0.048 troy oz) was suggested. 

In 1998, about 200 million automobiles were in circulation in the United States, and about 17 million automobiles 

were scrapped. If each catalytic converter in the scrapped 

automobiles contained an average of 1.5 g of platinum, then 

about 25,500 kg of platinum was available for recycling 

from this source. Of the 17 million scrapped automobiles, 

about 12 million were recycled through shredders (Fenton, 

1999, p. NN1). If it is assumed that the catalytic converters 

were collected from the automobiles prior to shredding, then 

18,000 kg of platinum was available for recycling. 

REFORMING CATALYSTS 

Heterogeneous catalysts containing platinum are widely 

used in the petroleum-refining industry for a variety of 

hydrocarbon conversion processes, including reforming. The 

products made by these processes, such as motor fuels and 

aromatic hydrocarbons, are of great economic value to the 

United States. For example, increasing the aromatic hydrocarbon content of gasoline raises the octane rating and 

lessens knocking. 

Catalysts in this service can be deactivated by several 

different mechanisms, but deactivation is primarily the result 

of deposition of carbonaceous materials onto the catalyst 

surface during hydrocarbon processing at elevated temperature. This deposit, known as coke, results in substantial deterioration in catalyst performance (Fung, 1993, p. 91–96). 

The catalyst activity, or its ability to convert reactants, is 

adversely affected by this coke deposition, and the catalyst is 

referred to as “spent.” 

The original performance of the fresh catalyst can be 

restored by proper regeneration to remove this coke (Kim 

and others, 1992, p. 39–46). Regeneration allows continued 

use of the same catalyst for many years. The actual loss of 

platinum during use by the petroleum industry is very small, 

and this efficient metal recovery contributes greatly to the 

economics of platinum use. There is a limit, however, to the 

number of times that a catalyst can be regenerated, and eventually the catalyst must be replaced. Many reforming and 

selective hydrogenation catalysts are regenerated two or 

more times. As a general rule, after a catalyst can no longer 

be regenerated to at least 75 percent of its original activity, it 

is reclaimed or discarded (Chang, 1998). 

When the catalysts are removed from service, they are 

sent to a toll refiner for recovery of the metal values, which 

are returned to the owner. About 70 percent of the replacement market is for the bimetallic form commonly consisting 

of 0.3 percent platinum and 0.3 percent rhenium. 

Monometallic catalysts average 0.4 percent platinum 

(Burke, 1979). It is estimated that the amount of platinum 

used in catalytic reforming in 1998 was over 40,200 kg and 

was increasing by about 6,200 kg each year. Because PGM’s 

are valuable, great care is exercised in monitoring all 

streams entering and leaving catalyst manufacturing sites to 

ensure that no significant amounts of material are lost. Yearly overall materials recovery rates of about 99.8 percent are 

attainable. 
B6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES


CHEMICAL-PROCESS CATALYSTS 

A typical use of a PGM catalyst in a chemical process is 

the production of nitric acid. During the manufacture of 

nitric acid by the oxidation of ammonia, platinum-rhodium 

and platinum-palladium-rhodium alloy gauzes are used as 

catalysts. Traditionally, the process is carried out at temperatures of 750°C to 950°C and at pressures of 101.3 to 1,013 

kilopascals. The amount of platinum lost from catalyst 

gauzes during nitric acid production depends upon the properties of the catalyst alloys, the operating conditions (temperature and pressure), and the technical control. The rate of 

platinum loss from a binary gauze consisting of 90 percent 

platinum and 10 percent rhodium varies from 0.05 g of platinum per metric ton of nitric acid produced in plants operated at atmospheric pressure (101.3 kilopascals) to 0.45 g of 

platinum for each metric ton of nitric acid produced in some 

high-pressure plants (Platinum Metals Review, 1999). In 

1998, the United States produced 9.3 million metric tons of 

nitric acid (Chemical & Engineering News, 1999). With that 

rate of nitric acid production, about 2,300 kg of platinum is 

estimated to have been consumed in this process. Not all of 

this material was allowed to escape into the atmosphere. Various filters and “gettering” devices allowed recovery of perhaps half of the lost metal. Of the platinum that escaped, 

most was probably trapped in absorption towers and ended 

up in the nitric acid. 

About 200 kg of platinum was consumed in other industrial or commercial catalytic applications. 

NEW SCRAP 

New scrap is defined as scrap produced during the manufacture of metals and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Typical sources of 

platinum new scrap are used equipment from the glass industry, jewelry, and electronic scrap (fig. 2). Platinum and platinum-rhodium alloys are basic to the glass industry and are 

used in a variety of glass-handling and -forming equipment. 

Platinum is used in these applications because of its high 

melting point, high-temperature strength, low oxidation rate, 

and noncontaminating behavior. Pure platinum is used to 

make stirrers and tanks and crucibles for melting glasses. 

Alloys of 90 percent platinum and 10 percent rhodium are 

used for the bushings and baskets needed in the production 

of glass fibers. This use represents a large application for 

platinum-rhodium alloys. Similarly, alloys of platinum and 

10 to 40 percent rhodium are used for crucible liners, structures conveying molten glass, fiber-optics-forming devices, 

laser-glass melters, and stirrers for glass homogenization. 

Very low metal losses are experienced in these uses. Worn 

parts are recycled on a toll basis, and the recovered metals 

are returned to the industry for fabrication into new parts. 

The platinum used in jewelry is theoretically available 

as an aboveground resource, but there is very little recycling, 

apart from machining chips and grindings resulting from 

jewelry fabrication. The machining chips and grindings are 

efficiently recycled. 

Precious metals in the electrical and electronic industries are dispersed in the assemblies, and until recently, little 

effort was made to recycle discarded scrap. Electronic scrap 

may contain recoverable amounts of gold, palladium, and 

silver but only trace levels of platinum (Hilliard and Dunning, 1983). The amount of platinum in electronic scrap may 

change dramatically as hard disk drives from computers 

manufactured after 1996 are scrapped. The first hard disk 

drives used 50 disks, each measuring 61 cm in diameter, to 

store just 5 megabytes of data. A typical modern personal 

computer can store 15 megabytes on a hard disk drive containing two or three disks that are only 9 cm in diameter. This 

efficiency was achieved by incorporating a platinum-cobalt 

magnetic layer on the surface of the disk to improve storage 

capacity. About 50 percent of the hard drives manufactured 

in 1998 used platinum, and it was estimated that in 2000 

more than 90 percent of the hard drives used magnetic thin 

films containing platinum (Johnson Matthey, 1999, p. 26). It 

will be several years, however, before these hard drives begin 

appearing in scrap streams for recycling. 

Almost all new PGM scrap generated is consumed. As 

shown in table 1, new scrap consumed in 1998 was estimated to have a platinum content of 5,600 kg, and the new-toold-scrap ratio was 42:58. 

HOME SCRAP 

In every company that manufactures semifinished and 

final PGM products, virtually all of the scrap generated is 

reprocessed for precious-metals recovery. Casting scrap, 

such as croppings of castings, is recovered simply by adding 

it to melt charges. This scrap is not counted as material consumed because it is endlessly recycled and never leaves the 

plant. Grindings, ingot scalping, and machining chips, which 

are processed through toll refining, are not home scrap. 

DISPOSITION OF PLATINUM SCRAP 

SCRAP CONSUMPTION 

Recovery of PGM’s from spent automobile catalysts is 

growing in the United States, where a network of recycling 

facilities is being put in place. This growth is due to the higher PGM loadings in automobile catalysts in recent years. 

Nevertheless, the amount of PGM’s recovered from catalysts 

remained only a fraction of the total amount consumed. In 

1998, more than 6,000 kg of PGM’s was recovered from 

spent automobile catalysts and other sources in the United 

States (Hilliard, 2000a). This represented about 8 percent of 

U.S. apparent consumption in 1998. More than 19,000 kg of

platinum in spent automobile catalysts and other scrap materials was exported to other countries (fig. 1) where the metal 

values were recovered and the recovered platinum sold back 

to the United States. 
PLATINUM RECYCLING IN THE UNITED STATES IN 1998	 B7


UNRECOVERED OLD SCRAP 

Only about 64 percent of the catalytic converters 

scrapped in the United States are being collected (Dhara, 

1983). Of these scrapped converters, less than 30 percent are 

being processed domestically for recovery of PGM content; 

about 30 percent are shipped to collection centers to await 

more favorable economic conditions before processing; 20 

percent are unrecovered. The remaining catalytic converters 

(20 percent) are exported to Japan and Europe for processing. 

OLD SCRAP RECYCLING EFFICIENCY 

Old scrap recycling efficiency shows the relation 

between old scrap materials recovered and reused and old 

scrap that is available to be recovered and reused. By definition, this relation is (the amount of old scrap consumed plus 

old scrap exported) divided by (old scrap generated plus old 

scrap imported plus any decrease in old scrap stocks or minus 

any increase in old scrap stocks). Platinum-bearing scrap 

materials consist mostly of spent catalysts from the automobile, chemical, and petroleum industries. In 1998, the chemical and petroleum industries recycled spent catalysts with 

recovery rates above 98 percent. Overall recycling efficiency 

for platinum was lower because of the many automobile catalysts that were not being recycled in 1998. Uncertainty in 

the exact value for recycling efficiency is increased because 

of lack of data on stocks of platinum-bearing material, but 

old scrap recycling efficiency is estimated at 76 percent. 

INFRASTRUCTURE OF PLATINUM SCRAP 

SCRAP COLLECTION SYSTEMS 

Anyone who owns a car manufactured in the United 

States after January 1, 1974, also owns a certain amount of 

automobile catalyst. Although spent automobile catalysts are 

readily available, collecting the material systematically is a 

complicated task. Because the catalysts are unevenly distributed, it is assumed that 20 to 40 percent of the total available 

catalysts will be either uncollected or unaccounted for 

(Dhara, 1983, p. 86). The flow of the material is unpredictable, as many factors, such as PGM prices, govern the 

collection effort. 

The low PGM content in automobile catalysts and the 

nature of the monoliths used as support have required the 

development of specialized recovery techniques, as well as 

the establishment of an infrastructure of collection centers. 

These factors have slowed the development of an automobile 

catalyst recycling industry. 

TRADE 

In 1998, the United States imported 103,000 kg of prefabricated platinum, unwrought platinum, platinum scrap, 

and other platinum materials. The value of these imports was 

$603 million. South Africa (69 percent), the United Kingdom (12 percent), and Germany (4 percent) were the major 

foreign sources of imports. The United States exported 

14,300 kg of refined platinum and 20,447 kg of platinum in 

scrap, ores, and concentrates. The value of these exports was 

$240 million (Hilliard, 2000b, p. 58.6). These quantities differ from those given in figure 1 because the U.S. Census 

Bureau reports some imports and exports as gross weight 

and estimates were made for the platinum content of these 

materials for inclusion in figure 1. 

In the first half of 1998, delayed shipments from Russia 

caused platinum prices to rise by more than $60 to reach a 

peak of $434 per troy oz on April 14. Prices began to fall 

soon afterward, following news that Russian export quotas 

had been approved. Platinum prices declined sharply from 

May through October 1998 because of the economic crisis in 

Asia and renewed financial and political uncertainty in Russia. As a result, the price of platinum sank to a 5-year low of 

$337 per troy oz in October. In 1998, the average annual 

price was $372.50 per troy oz (Hilliard, 2000b, p. 58.3). 

PROCESSING OF PLATINUM SCRAP 

Automobile and catalyst-canister manufacturers arrange 

to recover in-house stainless steel and PGM-bearing scrap 

materials. Once a canister containing PGM’s is mounted on 

a car that is sold, however, it is not regarded as an item for 

recovery by the manufacturers. Initially, each canister contains about 1.5 to 3 g of PGM’s; 1 to 3 micrograms of PGM’s 

are emitted per 1.6 kilometers from the exhaust systems of 

automobiles equipped with the canisters. For the present, the 

economic conditions of salvage through automobile scrap 

yards limit the amount of PGM’s recovered from this source. 

Several processes are available for recovering platinum from 

spent automotive industry catalysts: 

•	 Selective dissolution of the PGM’s from ceramic support 

in aqua regia. Soluble chloro-complexes of platinum, palladium, and rhodium are formed, and reduction of these 

compounds yields crude PGM’s for further refining. 

• 	Dissolution of the catalyst support in sulfuric acid, in 

which PGM’s are insoluble. This technique is widely 

used for the treatment of reforming and isomerization catalysts in which γ-alumina is the substrate but is not suitable for dissolution of the cordierite honeycomb substrates used in many automotive catalysts. 

• 	A gas-phase volatilization in which the PGM’s are selectively chlorinated to produce volatile compounds that are 

condensed in a cooler zone. 

•	 Blending of the catalyst with PGM concentrate to be 

refined by the same process as PGM ore (Dhara, 1983, 

p. 89).

In the United States, A-1 Specialized Services & Supplies, Inc., Croydon, Pa., and Multimetco, Inc., Anniston, 

Ala., are among the leading buyers and processors of scrap 

catalytic converter canisters. These companies have a network of collection points across the country and pay between 

$3.00 and $17.00 per canister (International Precious Metals 

Institute, 2000). 
B8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES


OUTLOOK 

The amount of platinum recovered from scrapped automobile catalysts continues to climb slowly and is expected to 

increase significantly in the long term because of increased 

demand for catalytic converters and platinum jewelry in 

Japan and China. Catalytic converters are the major source 

of platinum and other PGM’s for recycling. The outer shell 

of the converter is recycled for its stainless steel content, and 

the substrate is shipped to extractors to recover platinum, 

palladium, and rhodium. The U.S. price of steel scrap, a key 

ingredient of the steelmaking process, continues to be 

depressed, primarily because of the import of new foreign 

steel (Fenton, 2000, p. 40.1). With lower steel scrap prices 

there is less incentive to dismantle cars as dismantlers cut 

back in hope of a price rebound, resulting in fewer salvage 

catalytic converters coming to collection centers. In many 

instances, the converters that find their way to collection centers are exported to countries with lower labor cost—recycling catalytic converters is a labor-intensive task—allowing 

for the economic recovery of the PGM’s. The relatively low 

value of the metal content (about $19.00 in each converter), 

the low concentration of PGM’s (less than 0.1 weight percent), and the difficult logistics of returning the material to a 

central recycling location are reasons why recycling of PGM 

catalysts is not yet economically viable in the United States. 

Consequently, it is doubtful that there will be a significant 

increase in the reclamation of metals from automobile emissions control catalysts in the immediate future. 

Significant changes are on the horizon. The U.S. automobile industry has begun to enter the automobile recycling business, which could lead to an improved infrastructure of collection centers. Pending regulations will deter catalysts from 

entering landfills and will redirect spent catalyst traffic from 

disposal to regenerating and reclamation plants. Although the 

number of cars being scrapped in the United States is fairly 

constant, new sources of material, especially from Mexico, 

where new air-quality regulations are being considered, could 

increase significantly the number of catalytic converters available. Beginning in 2001, automobile manufacturers will shift to 

a more palladium-intensive catalyst. It will be 5 to 6 years, 

however, before any change is seen in the relative amounts of 

various PGM’s available for recycling. 

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May, 52 p. 

Kim, C.-S., Massoth, F.E., and Furimsky, Edward, 1992, Structure 

and catalytic activity of regenerated spent hydrotreating catalysts: Fuel Processing Technology, v. 32, no. 1–2, November, 

p. 39–46.

Page, N.J, Clark, A.L., Desborough, G.A., and Parker, R.L., 1973, 

Platinum-group metals, in Brobst, D.A., and Pratt, W.P., eds., 

United States mineral resources: U.S. Geological Survey Professional Paper 820, p. 537–545. 

Platinum Metals Review, 1999, Platinum loss from alloy catalyst 

gauzes in nitric acid plants: Platinum Metals Review, v. 43, no. 

2, April, p. 62–69. 

Roberts, J.D., and Caserio, M.C., 1965, Basic principles of organic 

chemistry: New York, W.A. Benjamin, Inc., 1,315 p. 

Roskill Information Services Ltd., 1991, The economics of platinum group metals 1991 (5th ed.): London, Roskill Information Services Ltd., 203 p. 

South Africa Department of Minerals and Energy, Minerals Bureau, 

1997, South Africa’s mineral industry, 1996/1997 (14th ed.): 

Braamfontein, South Africa, South Africa Department of Minerals and Energy, Minerals Bureau, November, 222 p. 

Stillwater Mining Company, 1999, 1998 annual report: Denver, 

Stillwater Mining Company, 98 p. 

Sutphin, D.M., and Page, N.J, 1986, International Strategic Minerals Inventory summary report—Platinum-group metals: U.S. 

Geological Survey Circular 930–E, 34 p. 

U.S. Mint, 1999, 1998 annual report: Washington, D.C., U.S. Mint, 

47 p. 

Wright, T.L., and Fleischer, Michael, 1965, Geochemistry of the platinum metals: U.S. Geological Survey Bulletin 1214–A, 24 p. 
PLATINUM RECYCLING IN THE UNITED STATES IN 1998 B9


APPENDIX—DEFINITIONS


γ-alumina. An activated form of alumina, made from Bayer 

α-trihydrate, widely used in adsorption and catalysis, 

where its large surface area, pore structure, and surface 

chemistry play an essential role. 

apparent consumption. Primary plus secondary production 

(old scrap) plus imports minus exports plus adjustments 

for Government and industry stock changes. 

apparent supply. Apparent consumption plus consumption of 

new scrap. 

aqua regia. Royal water, usually a solution of 1 part nitric 

acid and 3 parts hydrochloric acid used to dissolve platinum and other precious metals. 

catalyst. A substance that changes the rate of a chemical reaction but is itself not permanently changed in chemical 

form. 

chalcophilic. Having an affinity for sulfur. 

dissipative use. A use in which the metal is dispersed or scattered, such as paints or fertilizer, making it exceptionally 

difficult and costly to recycle. 

heterogeneous catalysts. Catalysts in which phase boundaries exist between the catalysts and the reacting substances, such as a solid catalyst in a gas or liquid phase 

reaction. 

home scrap. Scrap generated as process scrap and consumed 

in the same plant where generated. 

metal values. The amount of a specified precious metal or 

nonferrous scrap recovered by a refiner plus the cash 

value of other desirable metals recovered minus a penalty 

for undesired metals recovered. 

monolith. [monos, one + lithos, stone] A single ceramic block 

coated with catalytic materials. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from the 

recycling refiner, smelter, or processor. Excluded from 

new scrap is home scrap that is generated as process scrap 

and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed (for 

example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles 

that have been discarded after serving a useful purpose. 

Typical examples of old scrap are electrical wiring, leadacid batteries, silver from photographic materials, metals 

from shredded cars and appliances, used aluminum beverage cans, spent catalysts, and tool bits. This is also 

referred to as postconsumer scrap and may originate from 

industry or the general public. Expended or obsolete 

materials used dissipatively, such as paints and fertilizer, 

are not included. 

old scrap generated. Metal content of products theoretically 

becoming obsolete in the United States in the year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered 

and reused relative to the amount available to be recovered and reused. Defined as (consumption of old scrap 

(COS) plus exports of old scrap (OSE)) divided by (old 

scrap generated (OSG) plus imports of old scrap (OSI) 

plus a decrease in old scrap stocks (OSS) or minus an 

increase in old scrap stocks), measured in weight and 

expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

price. Based on unit value of platinum in materials.


primary platinum. Platinum derived from ore.


recycling. Reclamation of a metal in usable form from scrap


or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony 

in battery lead, recovery of copper in copper sulfate, and 

even the recovery of a metal where it is not desired but 

can be tolerated—such as tin from tinplate scrap that is 

incorporated in small quantities (and accepted) in some 

steels, only because the cost of removing it from tinplate 

scrap is too high and (or) tin stripping plants are too few. 

In all cases, what is consumed is the recoverable metal 

content of scrap. 

recycling rate. Fraction of the metal apparent supply that is 

scrap on an annual basis. It is defined as (consumption of 

old scrap (COS) plus consumption of new scrap (CNS)) 

divided by apparent supply (AS), measured in weight and 

expressed as a percentage: 

COS + CNS × 100 

AS 

reforming. A petroleum-refining process that uses a platinum 

catalyst to convert aliphatic hydrocarbons to aromatic 

hydrocarbons. Increasing the aromatic hydrocarbon content of gasoline raises the octane and lessens knocking 

secondary platinum. Platinum derived from or contained in 

scrap. 

siderophilic. Having an affinity for iron. 

toll refining. Custom refining of metal scrap or residue (feedstock) for which the refiner is paid an agreed fee (toll) for 

the recovery of specified precious metals or nonferrous 

scrap. The refined product is returned to the owner of the 

feedstock. 
U.S. Department of the Interior

U.S. Geological Survey

Chromium Recycling in the United States in 1998 

By John F. Papp 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–C

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Sources of Chromium-Containing Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Dissipated Materials Not Available for Recycling . . . . . . . . . . . . . . . . . . . . . . 4

Old Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Disposition of Chromium-Containing Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Infrastructure of Chromium-Containing Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Processing of Scrap Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Smelting/Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Fabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Outlook and Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

FIGURES 

1. Flow diagram showing U.S. chromium materials flow in 1998 . . . . . . . . . . . . . . . . C2 

2. Graphs showing U.S. chromium source materials and consumption by market


sector from 1978 through 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3. Graph showing U.S. chromium recycling trend as indicated by reported


consumption and receipts of stainless steel scrap from 1978 through 1998 . . . . . . . . 7

TABLE 

1. Salient statistics for U.S. chromium scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . C3 
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

million metric tons (Mt) 1,102,000 short ton 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Chromium Recycling in the United States in 1998 

By John F. Papp 

ABSTRACT 

The purpose of this report is to illustrate the extent to 

which chromium was recycled in the United States in 

1998 and to identify chromium-recycling trends. The 

major use of chromium was in the metallurgical industry 

to make stainless steel; substantially less chromium was 

used in the refractory and chemical industries. In this 

study, the only chromium recycling reported was that 

which was a part of stainless steel scrap reuse. In 1998, 20 

percent of the U.S. apparent consumption of chromium 

was secondary (from recycling); the remaining 80 percent 

was based on net chromium commodity imports and stock 

adjustments. Chromite ore was not mined in the United 

States in 1998. 

In 1998, 75,300 metric tons (t) of chromium contained 

in old scrap was consumed in the United States; it was valued at $66.4 million. Old scrap generated contained 132,000 

t of chromium. The old scrap recycling efficiency was 87 

percent, and the recycling rate was 20 percent. About 

18,000 t of chromium in old scrap was unrecovered. New 

scrap consumed contained 28,600 t of chromium, which 

yielded a new-to-old-scrap ratio of 28:72. U.S. chromiumbearing stainless steel scrap net exports were valued at $154 

million and were estimated to have contained 41,000 t of 

chromium. 

INTRODUCTION 

The chemical element chromium was discovered in 

1797 by Nicolas-Louis Vauquelin, a professor of chemistry 

at the Paris École des Mines, which was one of the new 

European technical universities established to bring science 

education to the mining industry (Weeks and Leichester, 

1968, p. 271–283). The mineral chromite, which consists 

primarily of chromium, aluminum, iron, magnesium, and 

oxygen, is a source of chromium. Chromite was first 

exploited for the production of pigments (Gray, 1988) and 

the manufacture of refractory materials. 

In the United States in 1998, the major use of chromium was in the metallurgical industry to make stainless steel; 

substantially less chromium was used in the refractory and 

chemical industries. The major chromium commodities are 

chromite ore, ferrochromium, and chromium chemicals, 

metal, and refractories. The major traded chromium commodity in the United States in 1998 was ferrochromium, 

which replaced chromite ore in 1983. Ferrochromium 

includes high-, medium-, and low-carbon ferrochromium; 

charge chrome is a type of high-carbon ferrochromium. 

Ferrochromium and ferrochromium silicon are chromium 

ferroalloys. 

More than half of the chromium consumed in the United States in 1998 was used in stainless steel; all grades of 

stainless steel contain appreciable amounts of chromium. To 

be used in stainless steel, chromite ore is first smelted into 

ferrochromium. Most ore is smelted near the chromite ore 

mine, but some is shipped to smelters near inexpensive electrical power sources or near stainless steel producers. Ferrochromium is mixed with iron to make stainless steel. 

The purpose of this report is to illustrate the extent to 

which chromium was recycled in the United States in 1998 

(fig. 1, table 1) and to identify chromium-recycling trends. 

Most recycled chromium was part of stainless steel scrap, 

and smaller amounts were in superalloys. In this study, the 

only chromium recycling reported was that which was a part 

of stainless steel scrap reuse. 

For the purpose of computing chromium supply from 

trade, the traded chromium commodities include chromite 

ore, chromium ferroalloys and metal, and selected chromium chemicals and pigments. On the basis of trade statistics 

and stainless steel scrap receipts reported by U.S. stainless 

steel producers, 20 percent of the 1998 chromium apparent 

consumption was secondary (from recycling of stainless 

steel scrap); the remaining 80 percent was based on net 

chromium commodity imports and stock adjustments. 

Chromite ore was not mined in the United States in 1998 

(Papp, 1999). 

On the basis of a different chromium material flow 

model, Gabler (1994, p. 18) estimated that in 1989, about 33 

percent of chromium material potentially available for recycling was recycled and that the recycled material accounted 

for 23 percent of 1989 apparent consumption. Although the 

models differed for this study and Gabler’s, the percentages 

of apparent chromium consumption from recycling were 

similar for 1989 (23 percent) and 1998 (20 percent). 

C1 
DOMESTIC SUPPLY OF UNWROUGHT DISTRIBUTION OF DOMESTIC SUPPLY OF UNWROUGHT

PRIMARY AND SECONDARY CHROMIUM PRIMARY AND SECONDARY CHROMIUM 

C2 

Release of Governmentand industry stocksof chromium ferroalloysand metal:

Government ............35.5Industry .....................1.76Imports of chromiummaterials:

Ferroalloys ..............245

Domestic productionof chromium chemical,ferrochromium, andrefractory materials ...140

Old scrap consumed ..75.3

New (prompt) scrap

Old scrapgenerated ........132

Old scrapsupply ...144

Old scrapexported ....50.7

Old scrapunrecovered ....18.0 

Old scrap stockdecrease ...2.14 

Chromiumproducts inchange ...+355 

Exports of chromium materials:

Chemicals ...................17.5

Net imports ofsemifabricatedproducts ...126 

Fabrication ofstainless steelproducts ....756

Home

scrap

Chromium productsto U.S. market ....619

Dissipative uses ....132 

New (prompt) scrapgenerated ....28.6

161Imports

Exports

35.1 

73.0 

522

22.5

487 

619 28.6 

132

544 

37.2

140

263

75.3

28.6 

9.69

2.14

50.7 18.0 

75.3 

Net oreimports ....77.7

Government and industryore stock changes ....62.4 

Home

scrap 

77.7

62.4 

132 

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES Total ....................37.2 Chemicals ...................9.07 Metal ...........................9.51 Total ....................263 consumed ..................28.6 Old scrap imported ...9.69 reservoir, net Ferroalloys ....................3.96 Metal .............................1.04 Total ........................22.5 

Figure 1. U.S. chromium materials flow in 1998. Values are in thousands of metric tons of contained chromium and have been rounded to three significant figures. In thisstudy, the only chromium recycling reported was that which was a part of stainless steel scrap reuse. 
CHROMIUM RECYCLING IN THE UNITED STATES IN 1998 C3 

Table 1. Salient statistics for U.S. chromium scrap in 1998. 

[Values in thousands of metric tons of contained chromium, 

unless otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75.3 

Value of old scrap consumed3 . . . . . . . . . . . . . $66.4 million 

Recycling efficiency4 . . . . . . . . . . . . . . . . . . . . . 87 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.0 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28.6 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . . . . . . 28:72 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 percent 

U.S. net exports of scrap10 . . . . . . . . . . . . . . . . . . . . . . . . . . 41.0 

Value of U.S. net exports of scrap11 . . . . . . . . . . . . . $154 million 

1Old scrap generated in 1998 is estimated to have been the chromium 

content of a fraction of the net stainless steel supply in 1968, as discussed in 

the text section “Old Scrap Generated.” The chromium fraction of stainless 

steel is estimated at 0.170 (Papp, 1991, p. 20). The fraction of the 1968 supply reporting to old scrap in 1998 was 0.894. The net stainless steel supply 

was shipments plus imports minus exports of stainless steel mill products. 

2Old scrap consumed is estimated to have been the chromium contained in stainless steel scrap receipts reported by consumers in 1998 less 

the sum of new scrap generated and scrap imports. 

3Value is estimated to have been the annual average unit value of 

high-carbon ferrochromium in 1998 ($882/t of chromium or $497/t gross 

weight of high-carbon ferrochromium) applied to old scrap consumed. This 

value is used because stainless steel scrap and ferrochromium compete as 

sources of chromium for the production of stainless steel (Papp, 2000). 

4Recycling efficiency is (old scrap consumed plus old scrap exported) 

divided by (old scrap generated plus old scrap imported plus any old scrap 

stock decrease or minus any old scrap stock increase). 

5Old scrap supply is old scrap generated plus old scrap imported plus 

old scrap stock decrease. 

6Old scrap unrecovered is old scrap supply minus old scrap consumed 

minus old scrap exported minus old scrap stock increase. 

7New scrap (also called prompt industrial scrap) consumption is not 

reported. It is estimated to be the new scrap generated. See text for estimation procedure. 

8New-to-old-scrap ratio is new scrap consumption compared with old 

scrap consumption, measured in weight and expressed in percentage of new 

plus old scrap consumption. 

9Recycling rate is old plus new scrap consumed divided by apparent 

supply expressed as a percentage. Chromium apparent supply is primary 

domestic chromium production (from mining, which was nil for the United 

States in 1998) plus secondary domestic chromium production (from old 

plus new stainless steel scrap) plus imports minus exports plus adjustments 

for Government and industry stock changes. Old plus new scrap consumed 

is estimated to be the chromium contained in stainless steel scrap receipts 

reported by Fenton (2000) and updated by Duane Johnson (U.S. Geological 

Survey, 2000, unpub data). Chromium apparent supply used here is the 

same as that reported in the U.S. Geological Survey Mineral Commodity 

Summaries, where it is called apparent consumption (Papp, 1999). 

10U.S. net exports of scrap are chromium contained in exports minus 

chromium contained in imports of stainless steel scrap. 

11Value of U.S. net exports of scrap is the value of stainless steel scrap 

exports minus imports as reported by the U.S. Census Bureau on the basis 

of data collected by the U.S. Customs Service. Stainless steel scrap has 

value for reasons other than its chromium content. 

In 1998, 75,300 metric tons (t) of chromium contained 

in old scrap was recycled in the United States; it was valued at $66.4 million. Old scrap generated contained 

132,000 t of chromium. The old scrap recycling efficiency 

was 87 percent, and the recycling rate was 20 percent. (See 

appendix for definitions.) About 18,000 t of chromium in 

old scrap was unrecovered. New scrap consumed contained 28,600 t of chromium, which yielded a new-to-oldscrap ratio of 28:72. The U.S. Census Bureau reported that 

U.S. chromium-bearing stainless steel scrap net exports 

were valued at $154 million in 1998 and were estimated to 

have contained 41,000 t of chromium. Trade data reported 

by the U.S. Census Bureau are based on data collected by 

the U.S. Customs Service. 

SOURCES OF CHROMIUM-CONTAINING 

SCRAP 

Figure 1 shows secondary chromium material supply, 

distribution, and recycling in the U.S. economy in 1998. 

Stainless steel scrap was the major source of recycled 

chromium and is the only type of scrap reported in figure 

1. In the United States, the average primary chromium supply distribution and usage trend in the metallurgical industry from 1983 through 1992, as measured by reported consumption, was stainless steel, 79 percent and increasing; 

alloy steel, 8 percent and decreasing; superalloys, 3 percent 

and increasing; and other uses, 10 percent (Papp, 1994, 

p. 68–70).

Steel production classifications include alloy steel 

(except stainless), carbon steel, and stainless steel. U.S. 

steel production by these classes is, in descending order of 

magnitude of production as a percentage of total averaged 

from 1993 through 1998, carbon steel, 88.8 percent; alloy 

steel, 9.17 percent; and stainless steel, 2.06 percent. In 

1998, U.S. carbon steel production was 88.0 million metric 

tons (Mt); alloy steel, 8.60 Mt; and stainless steel, 2.01 Mt. 

Relative to steel production, stainless steel production is 

small. 

In a world context, the United States accounted for 

12.6 percent of world steel production and 15.2 percent of 

world stainless steel production on the basis of data from 

1994 through 1998 (American Iron and Steel Institute, 

1999; INCO Limited, 1999, p. 3). In 1998, U.S. stainless 

steel producers reported stainless steel scrap consumption 

of 1.04 Mt (Fenton, 2000, and updates by Duane Johnson, 

U.S. Geological Survey, 2000, unpub. data), or 51.8 percent 

of that year’s stainless steel production. Consumption consisted of receipts of new, old, and home scrap. The chromium fraction of stainless steel is estimated at 0.170 (Papp, 

1991, p. 20). The 1.04 Mt of scrap was estimated to have 

contained about 177,000 t of chromium valued at $882/t 

and to have had a primary-chromium-material-equivalent 

value of $157 million. 
C4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

In 1998, reported receipts were 611,000 t of new and 

old stainless steel scrap, which were estimated to have 

contained 104,000 t of chromium. The difference between 

the chromium content of reported stainless steel scrap consumption and that of reported stainless steel scrap receipts 

was assumed to be equal to the chromium content of home 

scrap (73,000 t). 

Chromium is used in alloy, carbon, stainless, and tool 

steels; cast irons; chemicals; and superalloys. Chromite is 

used in refractories. The amount of chromium added to 

carbon and alloy steel is small, and chromium is included 

in only a few grades. Many grades of these alloys do not 

have any added chromium. As a result, when recycled, 

these alloys are not sought for their chromium content. 

Stainless and tool steels and superalloys are more valuable, contain greater amounts of chromium, and contain 

chromium more universally than do carbon or alloy steels. 

These materials are sought for recycling because of their 

high value, their high content of desirable elements (such 

as nickel, cobalt, molybdenum, and chromium), and their 

lack of undesirable, or tramp, elements. 

The carbon steel recycling rate is defined as carbon 

steel scrap consumption per carbon steel production on an 

annual basis. In the United States on average for 1994 

through 1998, it exceeded the stainless steel recycling rate 

by about 15 percent. All grades of stainless steel contain 

chromium, whereas only a few grades of carbon steel contain chromium, and the quantities are small compared with 

those in stainless steel. Because of these circumstances, 

the amount of chromium contained in recycled carbon 

steel cannot be confidently estimated, and carbon steel 

recycling is not considered to contribute to chromium 

recycling in this study. 

In the United States on average for 1994 through 

1998, alloy steel was recycled at less than one-sixth the 

rate of stainless steel. The alloy steel recycling rate was 

measured by comparing the ratio of alloy steel scrap consumption to alloy steel production with the ratio of stainless steel scrap consumption to stainless steel production 

(AISI, 1995–99). The amount of alloy steel recycled was 

nearly 1 Mt in 1998. Only a few grades of alloy steel contain chromium, and the amounts are small compared with 

those in stainless steel. Because of these circumstances, 

the amount of chromium contained in recycled alloy steel 

cannot be confidently estimated, and alloy steel recycling 

is not considered to contribute to chromium recycling in 

this study. 

Although the production of superalloys is small compared to that of stainless steel, their high value makes recycling superalloys cost effective. Nevertheless, data were 

not available to estimate the contribution of superalloy 

recycling to chromium recycling in this study. 

DISSIPATED MATERIALS NOT 

AVAILABLE FOR RECYCLING 

Dissipative uses do not result in new or old scrap generation in this model; they commonly involve dilution of 

the material or use in small volumes. Two broad categories 

of chromium products that are used dissipatively are chemicals and refractory materials; small amounts of chromiumcontaining steel can also be considered to be used dissipatively. For example, chromium is used in dyes and pigments 

that are subsequently incorporated in inks and paints. 

Because those inks and paints are used as thin coatings, the 

chromium becomes so diluted that recovery is uneconomic. 

Such materials leave the use cycle if incinerated or placed 

in a landfill. 

For the purpose of estimating the amount of dissipative 

use, chemical and refractory material production would be a 

good start except that such information is company confidential and, therefore, is not available for this calculation. 

Because imported chromite ore was used to make chromium chemicals, chromite-containing refractory materials, 

and chromium ferroalloys, net chromite ore imports can be 

used to estimate dissipative use. Inclusion of net trade in 

chromium chemicals and stock change of chromite ore to 

refine that estimate indicates that U.S. dissipative chromium 

use in 1998 was 132,000 t. 

Chromium ferroalloys are used to make the end-product 

iron and steel alloys discussed above. Some of that use is dissipative. The amount of chromite ore consumed in the United States in 1998 to make ferrochromium is the amount herein assumed to have been used dissipatively in metallurgical 

applications. Although there is no quantitative information 

about dissipative use, the assumption seems reasonable. 

Because chromium ferroalloy and metal production 

data for 1998 were withheld, estimates made for 1997 are 

assumed to apply. Domestic ferrochromium production is 

estimated to have been reported domestic chromium ferroalloy and metal production less domestic chromium metal 

production. Chromium metal production in 1998 is estimated to have been 2,000 t, implying that 38,900 t of chromium contained in stainless steel was used dissipatively. That 

was 10.6 percent of chromium contained in the net stainless 

steel supply. The net stainless steel supply was material that 

entered the marketplace in products; it is calculated as 

stainless steel shipments plus net imports of stainless steel 

mill products. Applying this result to 1998 data indicates 

that 38,900 t of chromium contained in the 1998 net stainless steel supply was used dissipatively in metallurgical 

applications, or about 11.4 percent of chromium contained 

in stainless steel production. Because chromium not used 

dissipatively becomes old scrap supply, the above assumption further implies that 88.6 percent of the net stainless 

steel supply in 1998 will become old scrap. 
CHROMIUM RECYCLING IN THE UNITED STATES IN 1998 

OLD SCRAP GENERATED 

Old scrap generated was estimated to be the net stainless 

steel supply of 30 years before 1998 adjusted for trade and 

dissipative use. Stainless steel is used in virtually all industry 

sectors. Stainless steel is stronger, more durable, and more 

valuable than common grades of steel. The actual lifetime of 

stainless steel parts depends on the specific applications, but 

data are lacking on the distribution of stainless steel by end 

use, average product life by end use, and recovered fraction 

by product; therefore, old scrap generated was estimated on 

the basis of the past domestic net stainless steel supply. 

From 1994 through 1998, the United States was a net 

exporter of stainless steel. U.S. stainless steel ingot exports 

were in the range of 0.4 to 0.6 percent of domestic stainless 

steel production; semifinished stainless steel exports were 4 

to 8 percent of that production. Stainless steel net exports in 

1968 are assumed to have been balanced by stainless steel 

contained in net manufactured product imports. This leaves 

dissipative uses in 1968 to be accounted for. The same dissipative use pattern discussed above for 1997 is assumed to 

apply to 1968. Therefore, dissipative uses in 1968 were 10.6 

percent of net stainless steel supply in 1968, leaving 89.4 

percent of that supply potentially available for recycling. 

Thus, 89.4 percent of the 1968 net stainless steel supply is 

the input to old scrap generated in 1998. 

Stainless steel production in 1968 contained about 

221,000 t of chromium. The net stainless steel supply (that 

is, stainless steel shipments plus imports minus exports) 

contained 148,000 t of chromium, of which 89.4 percent 

became the estimated amount of old scrap generated in 

1998, 132,000 t of chromium. 

In mining terms, a “resource” is material available 

regardless of the economics of recovery, and a “reserve” is an 

economically recoverable resource—old scrap generated is a 

resource, and old scrap consumed is a reserve (U.S. Bureau 

of Mines and U.S. Geological Survey, 1980). This resource 

may or may not have been collected, sorted if collected, or 

traded if sorted. In effect, the scrap industry must undo what 

the wholesale and retail trade industries do—the wholesale 

and retail trade industries take goods concentrated at the point 

of production and distribute them to consumers, whereas the 

scrap industry takes distributed materials and concentrates 

them so that they can reenter the production process. 

Various factors affect material collection and recycling 

(Aylen and Albertson, 1995). The availability of obsolete 

stainless steel scrap is price sensitive. In other words, when 

the price of scrap goes up, so does the supply of obsolete 

stainless steel scrap. The reason for this is that scrap collectors and processors stock obsolete stainless steel scrap until 

it becomes profitable for them to handle, process, and ship 

that material. On the basis of the resource/reserve analogy 

above, as price increases, resources become reserves. 

C5 

Old superalloy scrap is generated when parts made of 

superalloy material, such as jet engine parts, are replaced. 

Chemicals, such as plating and metal finishing baths, are 

processed to extend their useful life by removing contaminants. To the extent that this processing is recycling, it produces home scrap because such renewal is done within a 

plant. Refractory materials, such as chromite casting sand, 

are processed for reuse. To the extent that this processing is 

recycling, it produces home scrap because such reuse is 

done within a plant. 

Figure 2 shows the supply of chromium by material to 

the U.S. economy and the use of that material by end-use 

market sector. Figure 2A shows the distribution of chromite 

ore use by industry from 1978 to 1994; data are given individually for the chemical, metallurgical, and refractory 

industries from 1978 through 1985, but data are combined 

for the chemical and metallurgical industries from 1986 

through 1994 to protect company proprietary data. After 

1994, publication of chromite ore consumption by industry 

was discontinued to protect proprietary data. 

As shown in figure 2A, from 1978 through 1985, consumption of chromium from chromite ore by the chemical 

industry declined by 7 percent; consumption by the metallurgical industry dropped by half, to 65,200 t from 132,000 t; 

and consumption by the refractory industry dropped more 

than two-thirds, to 15,400 t from more than 53,800 t. Refractory industry consumption continued to drop until it reached 

less than 6,000 t in 1994, when reporting was discontinued. 

From 1979, a peak consumption year, to 1994, the chromium 

contained in the reported annual chromite ore consumption 

dropped to just more than 100,000 t from about 300,000 t. 

Chromite ore was being replaced by ferrochromium as the 

major source of chromium for the U.S. economy. Ferrochromium is used in the metallurgical industry, which is the 

major source and consumer of chromium-bearing scrap. 

Figure 2B shows the relative importance of the two 

major commercial sources of chromium in the United States 

during the 20 years, 1978–98. The figure shows that the 

dominant source of chromium for the U.S. economy shifted 

from chromite ore before 1981 to ferrochromium after 1983; 

for example, chromite ore supplied 61 percent of chromium 

contained in these imports in 1978, whereas ferrochromium 

supplied more than 67 percent of chromium in 1998. 

The major end use of chromium in the metallurgical 

industry is the manufacture of stainless steel. Figure 2C 

shows the inferred distribution of chromium among major 

end-use market sectors, which are electrical and electronic 

equipment, fabricated metal products, industrial and commercial machinery, and transportation. Transportation and 

industrial and commercial machinery each accounted for 

more than 40 percent of the total; fabricated metal products 

and electrical and electronic equipment each accounted for 

under 10 percent. 
C6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Chemical and metallurgical 

Refractory 

Chemical 

Metallurgical 

A, U.S. consumption of chromite ore 

350 

300 

250 

200 

150 

100 

50 

0 

THOUSANDS OF METRIC TONS

CONTAINED CHROMIUM, IN

1978 1980 1982 1984 1986 1988 1990 1992 1994 

YEAR 

700 

600 

500 

400 

300 

200 

100 

0 

B, Net U.S. imports for consumption 

THOUSANDS OF METRIC TONS

Ferrochromium 

Chromite ore 

CONTAINED CHROMIUM, IN

1978 1980 1982 1984 1986 	 1988 1990 1992 1994 1996 1998 

YEAR 

Industrial and commercial machinery 

Electrical and electronic equipment Fabricated metal products

C, Inferred U.S. stainless steel consumption by market sector 

200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

THOUSANDS OF METRIC TONS

Transportation 

CONTAINED STAINLESS STEEL, IN

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 

YEAR 

Figure 2. U.S. chromium source materials and consumption from 1978 through 1998. A, Reported 

U.S. consumption of chromite ore by the metallurgical, chemical, and refractory industries (data 

through 1994 only). B, Net U.S. imports for consumption by material. C, Inferred U.S. stainless 

steel consumption by market sector. 
CHROMIUM RECYCLING IN THE UNITED STATES IN 1998 C7 

250 

200 

150 

100 

50 

0


1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998


YEAR


Consumption 

Receipts 

Stainless steel scrap 

Figure 3. U.S. chromium recycling trend as indicated by reported consumption and receipts of CONTAINED CHROMIUM, IN THOUSANDS OF METRIC TONS

stainless steel scrap from 1978 through 1998. 

Figure 3 shows reported consumption and receipts of 

stainless steel scrap from 1978 through 1998. Assuming that 

scrap receipts are new or old scrap, one may infer that scrap 

receipts shown in figure 3 came from the end-use manufacturing processes shown in figure 2C or from the products of 

those uses. If the difference between scrap receipts and scrap 

consumption in figure 3 is home scrap, then the source of 

that scrap is the primary metals industry market sector. The 

figure shows a trend of increasing importance of new and old 

scrap, as shown by the increasing amount of scrap receipts 

compared with scrap consumption, during the 20-year period. Scrap receipts accounted for less than 36.8 percent of 

consumption in 1978 compared with 58.7 percent in 1998. 

NEW SCRAP 

New scrap results from steel fabrication processes. 

Stainless steel is either wrought or cast to make shapes, such 

as bars, plates, sheets, or strips, that are used to manufacture 

products. New scrap is valuable and is returned to the stainless steel producer through the supplier-purchaser channel or 

through scrap processors and dealers. 

New stainless steel scrap generation is proportional to 

stainless steel use. Reducing the amount of new scrap generated per unit of stainless steel production increases processing efficiency. The constancy of new scrap availability in the 

face of continued average production growth indicates that 

processing efficiency has increased coincident with and proportional to the growth in production. New scrap availability 

is not as price sensitive as old scrap availability because it is 

easier to collect, sort, and return new scrap; commonly, new 

scrap is returned under formal contract arrangements 

(Friedrich Terörde, ELG Haniel Group, U.S.A., 1997, written commun.). New scrap may also be called prompt industrial scrap because it is generated when industry manufactures products that use stainless steel and is returned as it is 

generated; that is, promptly. 

Stainless steel production has been growing; from 1950 

to 1996, the compounded annual growth for the major producing countries was 6.0 percent (INCO Limited, 1997, p. 

6). Annual growth of stainless steel production for these 

countries from 1986 through 1996 ranged in magnitude from 

as little as 0.04 percent to more than 14 percent. 

For the secondary material flow model used in this report, 

new scrap generated was estimated on the basis of information 

from Austin van’t Wout (Capricorn BV, Holland, 1998, written commun.) that 25 to 30 percent of scrap shipped by scrap 

suppliers to the stainless steel industry is new scrap. Thus, 

because scrap receipts were 58.7 percent of scrap consumption in 1998 and new scrap was 25 to 30 percent of scrap 

receipts (receipts by stainless steel producers being the same 

as shipments from scrap processors), new scrap was 14.7 to 

17.6 percent of stainless steel scrap consumption, and the newto-old-scrap ratio was 28:72. 

In written communications in 1997, P.J. Probert (Hernic 

Ferrochrome, South Africa) and Josephine Ward (Reward 

Raw Materials, Inc., Carnegie, Pa., U.S.A.) discussed secondary chromium consumption. Probert reported that stainless steel scrap typically provided 35 to 40 percent of the 

chromium required to produce stainless steel worldwide. For 

austenitic grades (those requiring nickel), scrap provided 45 

to 50 percent of the required chromium units. Ward estimated the lifetime of stainless steel products to range from 15 to 

20 years in the United States and stainless steel scrap to comprise 50 percent reclaimed (old scrap), 35 percent revert 

(home scrap), and 15 percent industrial (new scrap) in the 

United States. This estimate suggests that 65 percent of scrap 

consumption is receipts. U.S. stainless steel receipts and 

consumption reported to the U.S. Geological Survey (USGS) 

indicate that receipts averaged 59 percent of stainless steel 

scrap consumption during 1994 through 1998. The new 

scrap percentage of net stainless steel scrap consumption 

inferred in this report from other sources is 16.2 percent. 
C8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

In a study of nickel that is more recent than the studies 

cited in the previous paragraph, Salamon (2000) reported 

the lifetime of stainless steel in buildings to be 70 years; 

industrial plants, 35 years; and consumer products, 5 to 25 

years. 

Chemicals do not contribute to new scrap. 

DISPOSITION OF 

CHROMIUM-CONTAINING SCRAP 

Scrap processors collect old and new scrap, segregate it by grade, and cut it to usable size. They commonly mix scrap to meet the chemical specifications of the 

stainless scrap consumers who use it as a feed material 

for their furnaces. The USGS monitors scrap consumption of the U.S. stainless steel industry. The industry 

reports scrap receipts and scrap consumption. Stainless 

steel scrap accounting procedures do not differentiate old 

from new scrap. 

In the model presented here, the difference between 

old scrap supply and old scrap consumed is taken as the 

sum of old scrap exported, old scrap going into stocks, and 

unrecovered old scrap. The rate of recovery of old scrap 

from the general economy by scrap dealers and processors 

is unknown. Old scrap generated is an estimated number. 

Old scrap consumed is estimated to be the difference 

between scrap receipts (a surveyed quantity) and new 

scrap consumed (an estimated quantity). Unrecovered old 

scrap is estimated by balancing old scrap supply inputs 

and outputs. 

In 1998, 1.04 Mt of stainless steel scrap was consumed 

to produce 2.01 Mt of stainless steel. In other words, the 

stainless steel industry consumed the equivalent of 51.8 percent of production in stainless steel scrap, an amount similar to the overall steel industry recycling performance of 

58.4 percent, which is based on American Iron and Steel 

Institute (AISI) data averaged from 1994 through 1998 

(AISI, 1999). 

Individual stainless steel producers reported scrap 

usage ranging from 0 to 80 percent. One company reported feed consisting of 20 percent in-house (home) scrap, 

30 percent primary (previously unused) materials, and 50 

percent secondary materials (new plus old scrap). By 

using reported stainless steel scrap receipts and consumption, secondary supply could be estimated as 

receipts, and in-house scrap could be estimated as consumption minus receipts; by using production to estimate 

feed, primary supply could be estimated as production 

minus scrap consumption. For the U.S. stainless steel 

industry, this process averaged from 1994 through 1998 

yields the following stainless steel scrap types as percentages of stainless steel production: 22.2 percent inhouse scrap; 46.1 percent primary materials, and 31.7 

percent secondary materials. 

The U.S. Environmental Protection Agency (EPA) 

reported the release and transfer of from 12,000 t to 42,000 

t of chromium annually between 1987 and 1995 from the 

primary metals industry, which for chromium is the steel 

industry (Papp, 1994, p. 72; 1996; 1997, p. 182; 1998, p. 

196). In 1991, industry started reporting recycling as part 

of transfers (EPA, 1993, p. 6, 144, 162). As a result, transfers increased from about one-half of releases plus transfers 

to about three-fourths. One could conclude that in excess of 

one-half of the reported 40,000 t of transfers in 1991 were 

recycled. In the model used here, this material would be 

classified as either home or new (prompt) scrap. 

The above discussion of scrap disposition focuses on 

stainless steel scrap because it is accounted for separately 

from carbon steel, alloy steel, and superalloys. The 

chromium in stainless steel can reasonably be estimated, 

whereas the chromium in the other materials cannot, 

although brief discussions are provided above in the section, “Sources of Chromium-Containing Scrap.” 

OLD SCRAP RECYCLING EFFICIENCY 

Old scrap recycling efficiency is defined as old scrap 

consumed plus old scrap exported as a percentage of old 

scrap generated plus old scrap imported plus old scrap 

stock released; it shows the relations among what is theoretically available for recycling, what is recovered, and 

what is not recovered. For U.S. chromium in 1998, old 

scrap recycling efficiency was 87 percent. As mentioned 

above in the section on “Old Scrap Generated,” the availability of old stainless steel scrap is price sensitive. Therefore, the resource of old scrap is closely monitored and 

converted to commercial product when it is economically 

possible to do so. In an economic sense, old stainless steel 

scrap is being fully used consistent with the economic constraints placed upon its recycling by our economy. 

INFRASTRUCTURE OF 

CHROMIUM-CONTAINING SCRAP 

Scrap collection takes different forms on the basis of 

the kind and quantity of scrap. For example, scrap generated in the manufacturing process (new scrap) has value 

because its composition, quality, and origin are known. One 

recycling expense is the cost of separating materials into 

usable groups. Manufacturers can avoid this cost by not 

mixing incompatible materials, then returning the material 

to the metal producer for reuse. Recycling obsolete products 

is more labor intensive than recycling new scrap because the 

products are a mixture of materials that need to be segregated. For some products, high-value materials are efficiently 
CHROMIUM RECYCLING IN THE UNITED STATES IN 1998 

segregated from low-value ones. For example, automobile 

catalytic converters are housed in stainless steel cans. 

Because many automobiles are recycled, the cans are economically reclaimed and their material is reused. 

Although not all stainless steel in household products is recovered, much of the stainless steel in industrial products is. The stainless steel scrap industry includes 

suppliers of scrap to stainless steel producers and collectors of scrap who also sort material. Functions performed by these two groups—collecting, sorting, storing, and distributing—overlap. The scrap supplier takes 

on the responsibility for meeting the quality requirements of stainless steel producers. Scrap collectors are 

among their sources of scrap (Austin van’t Wout, 1998, 

written commun.). 

The U.S. Harmonized Tariff System categorizes 

chromium metal import trade into waste and scrap and 

other; “other” includes wrought and unwrought chromium alloys. The system makes no such breakdown for 

chromium metal exports. Vastly more chromium is traded 

as part of stainless steel than is traded in chromium waste 

and scrap. In 1998, U.S. exports of chromium metal 

(including waste and scrap) were 1,038 t; in contrast, 

stainless steel scrap net exports (net exports are old scrap 

exported minus old scrap imported) of 241,000 t, gross 

weight, contained an estimated 41,000 t of chromium. 

Chromium contained in stainless steel scrap net exports 

was 23 percent of chromium contained in domestic stainless steel scrap consumption. Only stainless steel scrap is 

included in this report because it dominates the quantity 

of chromium recycled and because it is the material for 

which information is available. 

PROCESSING OF SCRAP METALS 

SMELTING/REFINING 

In the steel industry, smelting is the process of converting iron ore into iron. Chromium plays no role in this 

process. In the chromium industry, smelting is the process 

of converting chromite ore into ferrochromium. Steelmaking, in particular stainless steelmaking, is a refining 

process that involves combining iron and alloying elements to convert iron into steel. Steel is iron with carbon 

added. Chromium is one of the alloying elements added to 

iron to make stainless steel. The source of chromium 

could be ferrochromium or stainless steel scrap. Ferrochromium is the primary supply because it comes 

directly from mined materials, and stainless steel scrap is 

the secondary material because it is recycled material. 

Stainless steel scrap is mixed with ferrochromium and 

other feed materials, melted, and refined. Because priC9 

mary and secondary materials are processed together in 

the stainless steelmaking process, secondary material 

metallurgical processing losses are the same as those of 

primary material. 

FABRICATION 

Scrap generated in the fabrication industry may 

require processing before it is reusable. For example, only 

certain sized objects are permissible for materials handling and furnace feed. Large objects must be cut; small 

ones, agglomerated. Contaminants must be removed. Cutting operations require lubricants that may have to be 

cleaned off of the metal before it is reused. 

OUTLOOK AND SUMMARY 

Chromium is recycled as part of stainless steel recycling. Once it is reclaimed, stainless steel scrap is 

processed and sold to be used as a feed material in the 

stainless steel production process. The scrap is mixed with 

other feed materials, including primary materials, and is 

melted and refined. 

The U.S. stainless steel industry in 1998 produced 

stainless steel scrap in excess of its needs. With a chromium recycling rate of 20 percent and old scrap recycling efficiency of 87 percent as interpreted in this model, chromium recovery from obsolete material might be improved. 

Figures indicate that in 1998, 18,000 t of chromium could 

theoretically have been obtained from unrecovered old 

scrap. Although furnaces in industrialized countries (probably including the United States) produced stainless steel 

using as much as 80 percent scrap, the U.S. market did not 

absorb this additional material under 1997–98 conditions 

of relatively strong demand. Price, of course, is a major 

inducement, and prices were relatively low in 1998. The 

18,000 t is an estimate that could be off for several reasons—dissipative use could have been underestimated, old 

scrap supply could have been overestimated, or high-cost 

stocks may have built up in scrap yards. 

New scrap recycling efficiency is high relative to that 

of old scrap and likely cannot be improved significantly. 

Recycling of stainless steel in a wide variety of products, 

however, is the area where attention could be focused. Some 

believe that greater design for recycling would aid in this 

effort for a more sustainable environment. In 1998, the 

United States had net exports of stainless steel scrap containing 41,000 t of chromium that earned the United States 

$154 million. The U.S. stainless steel industry reported consuming 1.04 Mt of home, new, and old stainless steel scrap 

that was estimated to have contained about 177,000 t of 

chromium and to have had a primary-chromium-materialequivalent value of $157 million. 
C10 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

REFERENCES CITED


American Iron and Steel Institute, 1968–99, Annual statistical 

report: Washington, D.C., American Iron and Steel Institute. 

Aylen, Jonathan, and Albertson, Kevin, 1995, Any old iron? The 

economics of scrap recycling: Manchester, England, Manchester Statistical Society, 14 p. 

Fenton, M.D. 2000, Iron and steel scrap: U.S. Geological Survey 

Minerals Yearbook 1998, v. 1, p. 40.1–40.19. (Also available 

online at http://minerals.usgs.gov/minerals/pubs/commodity/ 

iron_&_steel_scrap/360498.pdf.) 

Gabler, R.C., Jr., 1994, A chromium consumption and recycling 

flow model: U.S. Bureau of Mines Information Circular 

9416, 40 p. 

Gray, Alan, 1988, Lead chrome pigments, in Lewis, P.A., ed., 

Properties and economics; v. 1 of Pigments handbook: New 

York, Wiley-Interscience, p. 315–325. 

INCO Limited, 1997, World stainless steel statistics (1997 ed.): 

Toronto, INCO Limited, 126 p. 

_____1999, World stainless steel statistics (1999 ed.): Toronto, 

INCO Limited, 148 p. 

Papp, J.F., 1991, Chromium, nickel, and other alloying elements in 

U.S.-produced stainless and heat-resisting steel: U.S. Bureau 

of Mines Information Circular 9275, 41 p. 

_____1994, Chromium life cycle study: U.S. Bureau of Mines 

Information Circular 9411, 94 p. 

_____[1996], Chromium: U.S. Bureau of Mines Minerals Yearbook 1994, v. 1, p. 173–198. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/commodity/chromium/ 

180494.pdf.) 

_____[1997], Chromium: U.S. Geological Survey Minerals Yearbook 1995, v. 1, p. 169–195. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/commodity/chromium/ 

180495.pdf.) 

_____1998, Chromium: U.S. Geological Survey Minerals Yearbook 1996, v. 1, p. 183–210. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/commodity/chromium/ 

180496.pdf.) 

_____1999, Chromium: U.S. Geological Survey Mineral Commodity Summaries 1999, p. 48–49. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/commodity/chromium/ 

180399.pdf.) 

_____2000, Chromium: U.S. Geological Survey Minerals Yearbook 1998, v. 1, p. 17.1–17.32. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/commodity/chromium/ 

180498.pdf.) 

Salamon, Mike, 2000, Nickel: Seminar on Billiton Nickel, London, March 24, 2000, Proceedings, CD-ROM. 

U.S. Bureau of Mines and U.S. Geological Survey, 1980, Principles of reserve/resource classification: U.S. Geological Survey Circular 831, 5 p. 

U.S. Environmental Protection Agency, 1993, 1991 Toxics Release 

Inventory public data release: U.S. Environmental Protection 

Agency Report EPA 745–R–93–003, May, 364 p. 

Weeks, M.E., and Leichester, H.M., 1968, Discovery of the elements (7th ed.): Easton, Pa., Journal of Chemical Education, 

896 p. 
CHROMIUM RECYCLING IN THE UNITED STATES IN 1998 

APPENDIX—DEFINITIONS


apparent consumption. Primary domestic production plus 

secondary domestic production (old scrap) plus 

imports minus exports plus adjustments for Government and industry stock changes. For chromium, there 

is insufficient information about recycling to distinguish between new and old scrap consumption. 

Chromium apparent consumption is approximated by 

chromium apparent supply (see definition below) 

where new plus old scrap production is defined as 

stainless steel scrap receipts as reported in the U.S. 

Geological Survey’s Iron and Steel Scrap Survey (Fenton, 2000, and updates by Duane Johnson, 2000, 

unpub. data). 

apparent supply. Apparent consumption calculated with 

secondary production equal to new plus old scrap; see 

apparent consumption. 

dissipative use. A use in which a metal is dispersed or scattered, such as paints or fertilizer, making it exceptionally difficult and costly to recover the metal. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new 

scrap are borings, castings, clippings, drosses, skims, 

and turnings. New scrap includes scrap generated at 

facilities that consume old scrap. Included as new scrap 

is prompt industrial scrap—scrap obtained from a facility separate from the recycling refiner, smelter, or 

processor. Excluded from new scrap is home scrap that 

is generated as process scrap and used in the same 

plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal 

articles that have been discarded after serving a useful purpose. Typical examples of old scrap are electrical wiring, lead-acid batteries, silver from photographic materials, metals from shredded cars and 

appliances, used aluminum beverage cans, spent catalysts, and tool bits. This is also referred to as postconsumer scrap and may originate from industry or 

the general public. Expended or obsolete materials 

used dissipatively, such as paints and fertilizer, are 

not included. 

C11 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the year of 

consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

primary production. Chromium from ore. Because 

chromite ore was not mined in the United States in 

1998, the primary domestic production term used in 

calculating apparent consumption is zero. 

recycling. Reclamation of a metal in usable form from 

scrap or waste. This includes recovery as the refined 

metal or as alloys, mixtures, or compounds that are 

useful. Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of 

antimony in battery lead, recovery of copper in copper 

sulfate, and even the recovery of a metal where it is not 

desired but can be tolerated—such as tin from tinplate 

scrap that is incorporated in small quantities (and 

accepted) in some steels, only because the cost of 

removing it from tinplate scrap is too high and (or) tin 

stripping plants are too few. In all cases, what is consumed is the recoverable metal content of scrap. 

recycling rate. Fraction of the metal apparent supply that is 

scrap on an annual basis. It is defined as (consumption 

of old scrap (COS) plus consumption of new scrap 

(CNS)) divided by apparent supply (AS), measured in 

weight and expressed as a percentage: 

COS + CNS × 100 

AS 

secondary production. Chromium from recycling of new 

plus old scrap. 

superalloys. Alloys developed for high-temperature conditions where stresses (tensile, thermal, vibratory, and 

shock) are relatively high and where resistance to oxidation is required. 

value. Unit value of primary metal applied to primary metal 

contained in scrap. For chromium, the primary metal is 

ferrochromium. 
U.S. Department of the Interior

U.S. Geological Survey

Zinc Recycling in the United States in 1998 

By Jozef Plachy 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–D

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES

III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Global Sources of Zinc Ore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Sources of Zinc Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Disposition of Zinc Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Old Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Infrastructure of Zinc Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Processing of Zinc Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Brass and Bronze Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Galvanizing Residues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Die-Casting Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Zinc Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

EAF Dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Galvanized Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FIGURES


1. Flow diagram showing U.S. zinc materials flow in 1998 . . . . . . . . . . . . . . . . . . . . D2 

2. Graph showing U.S. slab zinc consumption by end-use sector


from 1978 through 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

TABLE


1. Salient statistics for U.S. zinc scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

For temperature conversions from degrees Celsius (°C) to degrees Fahrenheit (°F), use the following: 

°F = (1.8 × °C) + 32 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Zinc Recycling in the United States in 1998 

By Jozef Plachy 

ABSTRACT 

In 1998, about 426,000 metric tons (t) of zinc scrap 

was consumed in the United States; more than threefourths (344,000 t) was new scrap, and the remainder 

(82,000 t) was old scrap. The main sources for old scrap 

were brass and bronze scrap, galvanizing residues, diecasting scrap, zinc sheet, and flue dust from steelworking 

electric arc furnaces (EAF’s). 

Old scrap was a small part of the supply because 

many uses of zinc are dissipative, long term, or not conducive to economic collection and recycling. In 1998, 

about 23 percent of zinc products were made for dissipative uses. The recycling efficiency of old scrap was 

about 19 percent. 

Zinc in low concentrations is generally considered to 

be nontoxic. Consequently, recycling of zinc is driven 

primarily by the production cost of primary metal and 

the price of zinc and only to a lesser extent by environmental considerations. Because of the Government-mandated collection of flue dust, the only old zinc scrap that 

has an established system for collection and processing 

is EAF dust. 

In recent years, new technology to dezinc galvanized 

steel has been developed. It should increase the relatively 

low recycling rate of old zinc scrap. The total zinc scrap 

recycling rate in 1998 was estimated to be 27 percent, 

although it may be higher. Future technical and economic 

developments will increasingly favor the recycling of 

zinc, thereby enhancing the sustainability of primary zinc 

production. 

INTRODUCTION 

The purpose of this report is to show trends in consumption, loss, and recycling of zinc in the United States in 

1998 to illustrate the extent to which zinc was recycled (fig. 

1, table 1). The flow diagram in figure 1 shows the quantity 

of zinc present at different stages of recycling and use. As 

easily minable deposits become exhausted and the costs of 

primary zinc production and waste disposal increase, the 

recycling of secondary materials plays an ever-increasing 

role in the sustainability of natural resources. 

BACKGROUND 

Zinc is a bluish-white metal with a melting point of 

about 420°C and a boiling point of 907°C. The low melting 

point permits low-temperature casting, and the low boiling 

point is an important factor in purifying the metal by distillation and in producing high-purity metal dust and zinc 

oxide. Many minerals contain zinc, but sphalerite (zinc sulfide) is by far the most common zinc mineral. Mined ore is 

usually concentrated to about 55 percent zinc content at the 

mill and shipped to smelters. Concentrates are reduced to 

zinc metal by electrolytic deposition from a sulfate solution 

or by distillation in retorts or furnaces (Jolly, 1992). 

Measured in quantity produced, zinc is the fourth most 

important metal in the world after iron, aluminum, and copper. Although zinc was first produced in China in the 1st 

century A.D., it was not until the 18th century that it 

entered commercial production in Europe. In the early 

years, the principal uses of zinc were in sheet for building 

applications, in brass, and, to a lesser extent, in hot-dip galvanizing (immersion of steel or iron in molten zinc to form 

a coating to protect against corrosion). 

During the 1930’s, the use of zinc alloy castings 

became increasingly important with the rapid development 

of mass production, particularly of cars and appliances. By 

the 1940’s, galvanizing became the dominant use (Jolly, 

1997, p. 108). In 1998, an estimated 55 percent of zinc 

metal was used in galvanizing, followed by zinc-based 

alloys (19 percent) and brass and bronze (13 percent). The 

pattern of end uses of slab zinc (fig. 2) has a direct effect 

on the production and consumption of secondary zinc. 

GLOBAL SOURCES OF ZINC ORE 

Zinc was extracted from 20 mines in 7 States by 8 mining companies in 1998 (Plachy, 2000a). The United States 

accounted for 10 percent of world production; other leading 

producers were Australia, Canada, China, and Peru. The Red 

Dog Mine, which was operated by Cominco Alaska, Inc., 

produced more than one-half of the U.S. total zinc in concentrate, which amounted to 755,000 t in 1998 (Plachy, 2000b). 

Since the Red Dog Mine was opened in 1989, U.S. mine production has greatly exceeded the capacity of the three existing U.S. primary smelters, which totaled 234,000 t in 1998. 

D1 
DOMESTIC SUPPLY OF UNWROUGHT DISTRIBUTION OF DOMESTIC SUPPLY OF UNWROUGHT

PRIMARY AND SECONDARY ZINC PRIMARY AND SECONDARY ZINC 

Release of stocks of zinc:

Government .......... 26Industry ................. 12

l

Imports of zinc materials:

Compounds ....... 70

Domestic productionof zinc metal andcompounds ................ 660

Home

scrap Processing

losses .... 63

Old scrap consumed ... 82

New (prompt) scrapconsumed ...........344

New scrapimported ... 9 

New scrapfrom stocks ... 55 

Old scrap generated ..... 672

Old scrap supply .......... 702

Old scrapimported ... 30

Old scrapexported ... 35

Old scrap stockincrease ..... 80

Old scrapunrecovered ... 505 

Zincproductsnetchange ... +321 

Exports of zinc materials:

Metal ..................... 15

Fabrication:

Metal:

Brass and bronze ...168

Other ......................168

i

l 

Home

scrap 

Net imports ofsemifabricatedproducts .... 17 

Processinglosses ... 5 

Zinc productsto U.S.markets .... 1,291 

Dissipativeuses ... 298 

New scrapunrecovered .... 7 

New (prompt)scrap generated ... 287 

38949

597 

234

344

82 

82 

9 55 

280 

505 80 35 30 

672

1,584 

26

1,558 

1,291 

5 

993 

298

7 

287 

17 

63 

Ore:

U.S. ............ 192Imported ..... 42 

Tota ....................38

 Metal .................. 879

Total ................ 949

reservoir, 

 Compunds ............. 11 

Total ................. 26 

 Galvanizing ............709

 Zinc-based alloys ...245

Chem cals .................293 

Tota ..................1,583 

Total .......... 234 

D2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 1. U.S. zinc materials flow in 1998. Values are in thousands of metric tons of contained zinc. Sources of data are described in the section titled “Sources of Zinc Scrap.” 
ZINC RECYCLING IN THE UNITED STATES IN 1998 

Table 1. Salient statistics for U.S. zinc scrap in 1998. 

[Values in thousands of metric tons of contained zinc, unless 

otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 672 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 

Value of old scrap consumed3 . . . . . . . . . $71 million 

Recycling efficiency4 . . . . . . . . . . . . . . . . . 19 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 702 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . . . . 344 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . 81:19 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . 27 percent 

U.S. net exports of scrap10 . . . . . . . . . . . . . . . . . . . . . . . 5 

Value of U.S. net exports of scrap11 . . . . . . . . . $12 million 

1Zinc content of products theoretically becoming obsolete in the 

United States in 1998. Total consumption excludes dissipative uses. 

2Zinc content of products that were recycled in 1998. 

3The value of zinc scrap in 1998 was about $865/t contained zinc. 

4(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported plus any old scrap stock decrease or 

minus any old scrap stock increase). 

5Old scrap generated plus old scrap imported plus old scrap stock 

decrease. 

6Old scrap supply minus old scrap consumed minus old scrap exported 

minus old scrap stock increase. 

7Including new (prompt) industrial scrap but excluding home scrap. 

8Ratio of quantities consumed, in percent. 

9Fraction of the apparent metal supply that is scrap, on an annual basis. 

10Trade in scrap is assumed to be principally in old scrap. Net exports 

are exports of old scrap minus imports of old scrap. 

SOURCES OF ZINC SCRAP 

A small amount of scrap is generated during the production and processing of zinc (new scrap), most of which 

is easily recovered and recycled. Scrap generated only at 

the end of the useful life of the product into which it is 

incorporated (old scrap) is more difficult to recover; consequently, only a small portion is recycled. Until 1993, nearly all zinc used in galvanized steel products was lost either 

in landfills or in slag at steel scrap processing plants. 

In recent years, zinc has been recovered from flue dust, 

and new technology to dezinc galvanized steel has been 

developed. This new dezincing process should increase the 

relatively low recycling rate of old zinc scrap, thereby 

enhancing the sustainability of primary zinc production. 

The total zinc scrap recycling rate in 1998 was estimated to 

have been 27 percent (table 1). The balance of supply was 

primary material. 

D3 

Many metallic and virtually all chemical uses of zinc 

are essentially dissipative. Given the long life cycles for 

zinc products, a large amount of metallic zinc is still in use. 

Apart from what is now being recovered, small amounts of 

zinc-containing objects still end up in slag or landfills, from 

which an unknown amount of zinc may be leached by 

acidic water. A much smaller fraction of metallic zinc is 

vaporized and discharged to the atmosphere. 

In 1998, about 426,000 t of zinc scrap was consumed 

in the United States; more than three-fourths (344,000 t) 

was new scrap, and the remainder (82,000 t) was old scrap. 

The value of zinc in recycled scrap (old and new scrap consumed plus old scrap stock increase) was $437 million in 

1998. In 1990, the main sources for secondary zinc were as 

follows (Pocket Guide to World Zinc, 1996): brass and 

bronze scrap, 32 percent; galvanizing residues, 23 percent; 

die-casting scrap, 16 percent; zinc sheet, 10 percent; and 

flue dust from steelworking electric arc furnaces (EAF’s), 

8 percent. Percentages were probably similar in 1998. During 1998, about 795,000 t of zinc was unrecovered from old 

scrap or dissipated. The recycling efficiency of old scrap 

was about 19 percent (table 1). 

Most of the data in figure 1 were collected by the U.S. 

Geological Survey (USGS). The domestic supply of primary and secondary zinc shown in figure 1 is estimated 

from monthly and annual USGS surveys of domestic producers, data on sales from the U.S. Government’s National 

Defense Stockpile, import/export data compiled by the 

U.S. Census Bureau, and reported changes in producer, 

consumer, and merchant stocks. Reporting by producers 

and consumers of zinc is voluntary. 

The three largest secondary zinc producers do not 

report consumption of secondary zinc. Consequently, data 

concerning fabrication, production, and consumption of 

new and old scrap are mostly estimates based on survey 

forms compiled by the USGS and various studies carried 

out by individuals and organizations, such as the International Lead and Zinc Study Group. The 27-percent recycling rate shown in table 1 may actually have been much 

higher. According to IMCO Recycling, Inc. (1999), the 

world’s largest zinc recycler, the recycling rate for zinc in 

the United States could have been as high as 38 percent. 

DISPOSITION OF ZINC SCRAP 

Zinc in low concentrations is generally considered to 

be a nontoxic material. Consequently, recycling of zinc is 

driven primarily by the production cost of primary metal 

and the price of zinc and only to a lesser extent by environmental considerations. Because of the Governmentmandated collection of flue dust, the only secondary zinc 

that has an established system for collection and processing 

is EAF dust. Collection of other zinc scrap is done by either 

public organizations or private companies. 
YEAR

D4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

1400


1200


1000


800


600


400


200


0 

1978 1983 1988 1993 1998 

Galvanizing 

Brass and bronze products 

Zinc-based alloys 

Other uses 

EXPLANATION 

Figure 2. U.S. slab zinc consumption by end-use sector from 1978 through 1998. CONSUMPTION, IN THOUSANDS OF METRIC TONS 

OLD SCRAP 

Old scrap consists of used zinc products in the form of 

zinc metal or alloys, which have been discarded because of 

wear, damage, or obsolescence. This category includes diecastings, automobile shredder scrap, engraver plates, brass 

and bronze products, rolled zinc from roofing and gutters, 

dust and sludges from ironmaking and steelmaking, and 

contaminated waste solutions (mine waste, rinse effluents, 

waste plating solutions, and contaminated surface waters). 

In the past, the types of old scrap that were processed were 

limited by the ease of collection and the narrow range of 

composition. Therefore, only small amounts of old scrap 

were recycled. 

Environmental mandates that were passed in the 

1980’s broadened the types of old scrap collected by the 

recyclers by adding effluent zinc from recycling of galvanized steel scrap and zinc recovered from burning rubber 

tires. Despite Government-mandated efforts to protect the 

environment, only about 12 percent of the total zinc consumption in the United States was derived from old scrap 

in 1998. Old scrap was a small part of the supply because 

many uses of zinc are dissipative, long term, or not conducive to economic collection and recycling. In 1998, 

about 23 percent of zinc products were made for dissipative uses; dissipation can be either rapid (fertilizers, animal feed, fungicides, pharmaceuticals) or long term (corrosion of galvanized surfaces, rubber tire abrasion, flaking 

paint). Large amounts of zinc products are still in circulation because their usefulness may last 100 years. These 

products include zinc used in galvanizing and, in smaller 

quantities, in zinc-based alloys, brass, and bronze. About 

68 percent of U.S. zinc products made in 1998 will eventually be available as old scrap, but only a small portion of 

them will be recycled. 

NEW SCRAP 

New or prompt scrap is defined as that generated in 

manufacturing processes and consumed at plants other than 

where generated. Although the amount of new zinc scrap 

generated, which is estimated to have been 287,000 t in 

1998, is much smaller than the amount of old scrap generated (672,000 t), it constitutes more than three-fourths of 

consumed recycled zinc. Most of the new scrap is produced 

during fabrication before it becomes part of a product; 

therefore, it is easily collected for recycling. New scrap consists mostly of galvanizing residues that comprise a wide 

range of different materials, including ashes, flux residues, 

and top and bottom drosses; all have a very high content of 

zinc metal (Radiant Corp., 1976, p. 182). 

OLD SCRAP RECYCLING EFFICIENCY 

The recycling efficiency of old zinc scrap for 1998 in 

the United States is estimated at 19 percent; compared with 

the recycling efficiency of other metals, that of zinc is very 

low because nearly all chemical uses of zinc are virtually 

dissipative and because galvanized products have long life 

cycles before the zinc can be recovered. Like zinc alloys, 

including brass and bronze, galvanized steel is potentially a 

large source of secondary zinc. Because zinc is not a toxic 

metal, the increased recycling efficiency of zinc depends 

more on improving the technology to dezinc galvanized 

steel than on environmental protection requirements. 
ZINC RECYCLING IN THE UNITED STATES IN 1998 D5 

INFRASTRUCTURE OF ZINC SCRAP 

Although the exact number of recycling facilities is 

not known, the zinc recycling industry is dominated by 

IMCO Recycling, Inc., and Zinc Corporation of America. 

Together, they treated nearly three-fourths of all U.S. secondary zinc in 1998. Most of the recycling plants were in 

Michigan, Pennsylvania, Tennessee, and Texas. 

Because most zinc metal is used for corrosion protection of iron and steel, the largest portion of recycled zinc 

is supplied by steel industries either as galvanizing 

residues or as flue dust. Galvanizing residues contain 

between 90 and 95 percent zinc and 5–10 percent other 

metals. Depending on the steel type and the galvanizing 

process, between 10 and 40 percent of the total zinc consumed ends up in residues. Zinc, which is metallurgically 

combined with steel during galvanizing, cannot be easily 

separated from galvanized steel scrap. It is usually recovered from flue dust generated during reprocessing of steel 

scrap. This dust contains an average of 20 percent zinc, 

which is generally recovered as crude zinc oxide for zinc 

metal production. 

Because the largest consumer of zinc is the steel 

industry, the largest consumers of galvanizing residues 

and flue dust are located near large steelworks. Collection of secondary zinc is usually based on long-term 

agreements between steel producers and secondary zinc 

consumers. 

As is the case with galvanized steel, zinc die-cast 

components enter the recycling stream as a function of the 

number and type of products used. Old die-cast components provide high metal recovery, but the recovery of the 

products in which they are contained is typically low. 

About one-third of U.S. consumption of zinc in 1998 

came from domestic primary and secondary production. 

The balance was supplied by imports, mostly from Canada. Trade in zinc scrap was relatively small compared with 

trade in zinc concentrate and zinc metal. Most of the zinc 

scrap exports were shipped to Asia, primarily to Taiwan. In 

1998, more than 90 percent of scrap imports came from 

Canada. 

PROCESSING OF ZINC SCRAP 

Zinc can be recycled again and again without loss of 

its original properties. Its low melting and boiling points 

make zinc relatively easy to recycle. The main sources for 

secondary zinc, listed in decreasing order of use, are brass 

and bronze scrap, galvanizing residues, die-casting scrap, 

zinc sheets, and flue dust from steelworking electric arc 

furnaces (EAF’s). Processing methods for these scrap 

materials are described below, as is a new dezincing 

process that should increase the recycling of galvanized 

steel scrap. 

BRASS AND BRONZE SCRAP 

With its high value and high copper content, brass and 

bronze scrap is recycled almost exclusively by the brass 

and copper industries. Effectively, this means that zinc 

used in brass leaves the zinc recycling circuit and is completely recycled within the brass/copper circuit. However, 

it is included in the materials flow depicted in figure 1. “It 

is a common practice to boil secondary zinc alloys [in 

muffle furnaces or retorts] and evaporate zinc away from 

the alloying elements” (Schau, no date). The zinc vapor 

can be purified in a distillation column to produce refined 

zinc metal. 

GALVANIZING RESIDUES 

Because of environmental restrictions and the high 

content of entrained zinc metal, galvanizing residues 

(which comprise top and bottom drosses, skimmings, and 

ashes) are the second most commonly recycled zinc scrap. 

Most galvanizing residues are cast into slabs as discussed 

below, but some other processing methods are used. 

Combining drosses with fluxes.—Galvanizers’ drosses are metallic alloys of iron and zinc plus some unalloyed zinc and other metals, mainly aluminum, lead, and 

tin. The bottom dross consists mainly of iron and zinc. 

Because it is heavier than the molten zinc, it sinks to the 

bottom of the galvanizing pots. The light, top dross contains primarily zinc and aluminum with small amounts of 

iron, lead, and tin. Both these drosses can react with various fluxes to release the entrapped metallic zinc, which is 

cast into slabs for subsequent use by secondary zinc 

smelters. 

Treating skimmings and ashes.—Skimmings and 

ashes are formed by oxidation on the surface of galvanizing baths when no flux is used. High-grade skims are used 

directly by secondary producers. Medium- and low-grade 

skims generally undergo an intermediate reduction-distillation-pyrometallurgical step to upgrade the zinc content 

before treatment, or they are leached with acid, alkaline, 

or ammoniacal solution to extract zinc, which is subsequently recovered as a compound by crystallization or as 

a salable chemical product retained in solution. 

Casting galvanizing residues into slabs.—Most of the 

galvanizing residues are cast into slabs and fed into furnaces that are stationary, horizontal, or tilted. Most of the 

furnaces are fired with either natural gas or oil. Feed is 

placed in a retort through which a flame passes and heats 

up the charge to the boiling point. The fumes pass through 

the neck of the retort into a condenser, where they are 

cooled to form either metal or dust, depending on the type 

of condenser. Recovery efficiency is very high from simple remelting but declines as the number of processing 

steps increases (Edwards, 1977, p. 5). 
D6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

DIE-CASTING SCRAP 

New die-casting scrap is recycled directly and qualifies 

as home scrap. Old scrap, which includes, in particular, that 

from shredding of cars and domestic appliances, can be 

used in the production of zinc dust and zinc oxide and as a 

feedstock for smelters. 

ZINC SHEETS 

Zinc sheets are generally old scrap from roofs, 

cladding, gutters, and downspouts, together with some “cutoffs” from the use of new sheet. This material is the most 

sought after by zinc recyclers, because it can be readily used 

by secondary or primary zinc producers. 

EAF DUST 

The use of zinc for galvanizing has grown very substantially in the last 40 years, but owing to the long life of 

galvanized products, this source has only recently appeared 

in substantial quantities as scrap. After reauthorization of 

the Resource Conservation and Recovery Act in 1984, 

which substantially raised the disposal cost of EAF dust, the 

recycling of EAF dust is estimated to have increased to 

about 75 percent in 1998 from 30 percent in 1984. Inclusion 

of EAF dust in the hazardous waste list created a market for 

approximately 500,000 t per year of flue dust (Consolidated 

Materials Brokers, L.L.C., 1998). Zinc content ranges from 

about 5 percent to nearly 40 percent zinc (average about 20 

percent), and the dust contains small amounts of hazardous 

constituents, including cadmium, chromium, and lead. 

The first treatment of flue dust is usually carried out 

close to secondary steel plants. The predominant technology used for the recovery of zinc from EAF dust is the Waelz 

kiln process. The EAF dust is mixed with coal and flux and 

fed to the kiln, where materials roll along the inside slope. 

Occasionally, energy provided by coal combustion is supplemented by natural gas or oil combustion via a burner at 

the discharge end of the kiln. The feed is reducing and oxidizing simultaneously in the kiln, thus generating two marketable products—a mixed zinc/lead oxide and an inert 

iron-rich slag. Most of the crude zinc/lead oxide, which 

contains about 55 percent zinc, is reused by the Zinc Corporation of America at its Monaca, Pa., plant for production 

of zinc metal and refined oxide. Slag, which contains 

between 30 and 35 percent iron, is sold as road base, antiskid agent, portland cement additive, and an aggregate in 

highway blacktop (Kern and Mahler, 1987, p. 8). 

GALVANIZED STEEL SCRAP 

Metal Recovery Technologies, Inc., installed a pilot 

plant in East Chicago, Ind., that converted galvanized steel 

scrap into clean scrap for steelmaking and zinc solution. 

The new process used in this plant consisted of dissolving 

the zinc coating from scrap in a hot, caustic solution and 

recovering the zinc from the solution electrolytically. 

Because the electrolyte was reused, waste was minimal 

compared with waste caused by processing of flue dust 

(Argonne National Laboratory, Transportation Technology 

Research and Development Center, 1998). 

OUTLOOK 

The changes in end-use patterns of zinc and the overall 

increase in consumption mean that considerably increased 

amounts of zinc will be available for recycling, despite the 

long lifetime of zinc products. As with other materials, future 

technical and economic developments, such as efficient separation of zinc from galvanized steel, will increasingly favor 

the recycling of zinc. 

Environmental considerations, technological advances, 

and the economics of primary and secondary production are 

the major reasons for increased recycling of all metals. In 

the past, only new zinc scrap was recycled. As time progressed, old scrap was recycled, and old scrap recycling 

efficiency began to increase. Although zinc is not a hazardous material, high concentrations of it could harm the 

environment. The nature of the principal uses of zinc and 

established recycling circuits, however, ensure that zinc is 

rarely an environmental threat. 

Past patterns of use indicate that increasing amounts 

of zinc will be used for galvanizing. Therefore, the development of economically efficient recycling of galvanized 

scrap should increase the recycling rate of old scrap. With 

the growing availability of valuable secondary materials 

and increased efficiency of zinc recovery, the amount of 

zinc coming from secondary sources should increase 

steadily. An increase or decrease of recycling capacity will 

depend mainly on the relative cost of recycling and 

changes in regulations governing disposal of secondary 

zinc. 

The recycling rate of zinc, however, will probably not 

approach that of some of the other major metals because 

many uses of zinc are dissipative or nonrecoverable. For 

example, zinc used in fertilizers or animal feed is essentially unrecoverable, and zinc in paints or in rubber products has, at best, only limited recoverability (Munford, 

1998). 

Despite a relatively low recycling rate, the recycling 

industry enhances the sustainability of zinc production 

by reducing the need for primary production, thereby 

saving energy and extending the longevity of natural 

resources. 
ZINC RECYCLING IN THE UNITED STATES IN 1998 

REFERENCES CITED


Argonne National Laboratory, Transportation Technology 

Research and Development Center [1998?], Dezincing galvanized metal provides clean scrap for steelmaking: web site at 

http://www.transportation.anl.go v/ttrdc/research/ 

waste_recovery/zinc.html. (Accessed April 24, 2000.) 

Consolidated Materials Brokers, L.L.C. [1998?], Recycling steel 

mill waste: web site at http://www.ceramics.com/cmb/#11. 

(Accessed April 25, 2000.) 

Edwards, J.O., 1977, The potential of recycling in zinc conservation: Canada Department of Energy, Mines and Resources, 

Mineral Research Program, Physical Metallurgy Research 

Laboratories Report MRP/PMRL–77–6 (OP), 20 p. 

IMCO Recycling, Inc. [1999], Our markets: web site at 

http://www.imcorecycling.com/markets/mkt_main.html. 

(Accessed April 25, 2000.) 

Jolly, J.H., 1992, Materials flow of zinc in the United States 

1850–1990: U.S. Bureau of Mines Open-File Report 72–92, 

52 p. (Also available online at http://greenwood.cr.usgs.gov/ 

pub/min-info-pubs/usbm-ofr/ofr-72-92.) 

_____1997, U.S. zinc industry: Baltimore, Md., American Literary 

Press, Inc., 312 p. 

D7 

Kern, P.L., and Mahler, G.T., Jr., 1987, The Waelz process for 

recovering zinc and lead from steelmaking dust: The Metallurgical Society Technical Paper no. A88–5, p. 1–11. 

Munford, Chris, 1998, Recovery rate for zinc scrap on increase: 

Metal Bulletin, no. 8284, June 8, p. 12. 

Plachy, Jozef, 2000a, Zinc: U.S. Geological Survey Minerals Yearbook 1998, v. 1, p. 85.1–85.9. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/commodity/ 

zinc/720498.pdf.) 

_____2000b, Zinc: U.S. Geological Survey Mineral Commodity 

Summaries 2000, p. 190–191. (Also available online at 

http://minerals.usgs.gov/minerals/pubs/commodity/ 

zinc/720300.pdf.) 

Pocket Guide to World Zinc, 1996, Main sources of zinc for recycling: 

web site at http://www.eazall.com/pgwz/pgwz0015.htm. 

(Accessed August 20, 1996). 

Radiant Corp., 1976, Industry profile, in Multimedia environmental assessment of the secondary nonferrous metal industry: 

Cincinnati, Ohio, U.S. Environmental Protection Agency, 

p. 179–196. 

Schau, Tore [no date], Distillation of zinc: web site at http://www. 

zincrecycling.com/distilla.htm. (Accessed April 25, 2000.) 
D8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

brass. An alloy of copper and zinc that may contain other 

elements such as aluminum, iron, manganese, nickel, 

tin, and lead. 

bronze. An alloy of copper and tin that may contain other 

elements such as aluminum, silicon, and zinc. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it 

exceptionally difficult and costly to recycle. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

hot-dip galvanizing. Immersion of steel or iron in molten 

zinc to form a coating to protect against corrosion. 

new scrap. Scrap produced during the manufacture of metals and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new 

scrap are borings, castings, clippings, drosses, skims, 

and turnings. New scrap includes scrap generated at 

facilities that consume old scrap. Included as new 

scrap is prompt industrial scrap—scrap obtained from 

a facility separate from the recycling refiner, smelter, 

or processor. Excluded from new scrap is home scrap 

that is generated as process scrap and used in the same 

plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal 

articles that have been discarded after serving a useful purpose. Typical examples of old scrap are electrical wiring, lead-acid batteries, silver from photographic materials, metals from shredded cars and 

appliances, used aluminum beverage cans, spent catalysts, and tool bits. This is also referred to as postconsumer scrap and may originate from industry or 

the general public. Expended or obsolete materials 

used dissipatively, such as paints and fertilizers, are 

not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

price. Based on the unit value of zinc in materials.


primary zinc. Zinc derived from ore.


recycling. Reclamation of a metal in usable form from scrap


or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

secondary zinc. Zinc derived from or contained in scrap. 

slab zinc. A general term for commercial zinc cast in various shapes and sizes. 
U.S. Department of the Interior

U.S. Geological Survey

Magnesium Recycling in the United States in 1998 

By Deborah A. Kramer 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–E

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Global Geologic Occurrence of Magnesium . . . . . . . . . . . . . . . . . . . . . . . . . .1

Production Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Sources of Magnesium Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Disposition of Magnesium Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Infrastructure of Magnesium Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Locations of Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Trade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Processing of Magnesium Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Structural Magnesium-Base Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Used Beverage Can Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Aluminum-Magnesium Alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Titanium Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

FIGURES


1. Flow diagram showing U.S. magnesium materials flow in 1998 . . . . . . . . . . . . . . . E2

2. Graph showing U.S. magnesium end-use patterns from 1979 through 1998 . . . . . . . 4

3. Graph showing average U.S. spot Western magnesium prices . . . . . . . . . . . . . . . . . . 5

4. Flow diagram showing simplified used beverage can processing . . . . . . . . . . . . . . . . 9

TABLES


1. Salient statistics for U.S. magnesium scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . .E3

2. Major U.S. magnesium-base scrap processors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

3. Used beverage can scrap melting data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

million metric tons (Mt) 1,102,000 short ton 

For temperature conversions from degrees Celsius (°C) to degrees Fahrenheit (°F), use the following: 

°F = (1.8 × °C) + 32 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Magnesium Recycling in the United States in 1998 

By Deborah A. Kramer 

ABSTRACT 

As concern for the environment has grown in recent 

years, the importance of recycling has become more evident. The more materials that are recycled, the fewer natural resources will be consumed and the fewer waste products will end up in landfills, the water, and the air. As one of 

a series of reports on metals recycling, this report discusses 

the 1998 flow of magnesium in the United States from 

extraction through its uses with particular emphasis on recycling. In 1998, the recycling efficiency for magnesium was 

estimated to be 33 percent—almost 60 percent of the magnesium that was recycled came from new scrap, primarily 

waste from die-casting operations. The principal source of 

old scrap was recycled aluminum beverage cans. 

INTRODUCTION 

Figure 1 and table 1 provide a snapshot of the U.S. 

magnesium recycling industry in 1998. This materials flow 

study shows the extent of magnesium recycling and identifies the consumption, losses, and trends in the U.S. secondary magnesium industry. In 1998, approximately 33 percent 

of the magnesium consumed in the United States came from 

recycled magnesium; almost 60 percent of this recycled 

magnesium was derived from new scrap. 

GLOBAL GEOLOGIC OCCURRENCE 

OF MAGNESIUM 

Magnesium is the eighth most abundant element and 

constitutes about 2 percent of the Earth’s crust. It is the third 

most plentiful element dissolved in seawater with a concentration that averages 0.13 percent. Although magnesium is 

found in more than 60 minerals, only brucite, carnallite, 

dolomite, magnesite, and olivine are of commercial importance. Magnesium metal is produced from seawater, well 

and lake brines, and bitterns, as well as from the minerals 

carnallite, dolomite, and magnesite (Bodenlos and Thayer, 

1973). 

Primary magnesium is produced in Brazil, Canada, 

China, France, India, Israel, Kazakhstan, Norway, Russia, 

Serbia and Montenegro, Ukraine, and the United States. In 

the study year, 1998, primary magnesium was produced in 

the United States by three companies—Dow Chemical Co., 

Freeport, Tex., Magnesium Corp. of America (MagCorp), 

Rowley, Utah, and Northwest Alloys Inc., which is a subsidiary of Alcoa Inc., Addy, Wash. Dow closed its magnesium operation in November 1998. 

PRODUCTION TECHNOLOGY 

Magnesium is manufactured by two methods— thermic 

reduction of dolomite or electrolytic reduction of magnesium chloride. Two thermic processes are in use to recover 

magnesium metal from dolomite—the Pidgeon and the 

Magnetherm. Although both use the same basic chemistry, 

the Pidgeon process uses an external heat source, and the 

Magnetherm process uses heat generated by the electrical 

resistance of the reactants. In the Pidgeon process, dolomite 

and ferrosilicon are formed into briquettes and heated in a 

retort under a vacuum. Magnesium oxide in the dolomite 

reacts with the ferrosilicon to produce magnesium vapor, 

which is cooled, condensed, and collected in a separate section of the retort. In the Magnetherm process, calcined 

dolomite, ferrosilicon, and alumina are heated under a vacuum. Alumina reduces the melting point of the slag produced by the dolomite-ferrosilicon reaction to make resistance heating practical. Magnesium vapor is cooled and condensed in a condensing chamber. 

Electrolytic recovery of magnesium requires a magnesium chloride feedstock that normally is prepared from seawater or brines. Two types of magnesium chloride can be 

made—hydrous and anhydrous. In the preparation of 

hydrous magnesium chloride, which was used by Dow until 

1998, magnesium hydroxide is precipitated from seawater 

by the addition of dolomitic limestone. Adding hydrochloric acid to the magnesium hydroxide produces a neutralized 

magnesium chloride solution. This solution is dehydrated 

until it contains about 25 percent water and then is fed 

directly to electrolytic cells. 

MagCorp uses an anhydrous magnesium chloride feed 

for their electrolytic cells. Solar evaporation initially concentrates the magnesium chloride brines from the Great Salt 

Lake. After adding calcium chloride to precipitate sulfate 

impurities and removing boron by solvent extraction, the 

brine is concentrated further and dehydrated in a spray 

E1 
DISTRIBUTION OF DOMESTIC SUPPLY OF UNWROUGHT

PRIMARY AND SECONDARY MAGNESIUM

DOMESTIC SUPPLY OF UNWROUGHT PRIMARY

AND SECONDARY MAGNESIUM 

Homescrap . .12

Buildup of industry stocksof magnesium metal . . . 1 

231 

174 49 

260

108 

28 

Fabrication . . . 243 

12 Processing

losses . . . 8

8 

Exports ofmagnesium metal . . . 28 

43 

Dissipativeuses . . . 45 

1

New scrapexported . . 1

New (prompt) scrapgenerated:

Trimmings/chips . . 43

5

Reject parts . . . . . . . . 1

49

W 

1 

Imports of magnesiummetal . . . . . . . . . . . . . 77

Domestic production of

magnesium metal . . .106 

45 

New (prompt) scrap consumed:

Trimmings/chips . . . . . . . 39

2 

Magnesiumproducts to U.S.market . . . . 174 

4

W 

32 

68 

32 

108 

1 

Old scrapexported . . 12 

Old scrapimported . . 4

Old scrapstock increase 

12

Old scrapsupply . . 12 

Magnesiumproductsreservoir netchange . . (+25) 

77 

41 133 4 

W 

Processinglosses (UBCrecycling) . . .11 

11 

43 

Unrecovered new scrap:

Trimmings/chips . . . 1 

Old scrap consumed:

106 

New scrapimported . . 2 

New scrapfrom stocks

 Old scrap unrecovered:

Old scrap generated:

Other . . . . . . . . . . . . 4

. . . . . . 38

Tools/machinery Al, Mg) . . . 19

Total . . . . . . . . . . . . . . 108 

New scrapinto stocks

 Drosses . . . . . . . . . . 

Total . . . . . . . . . . .

Drosses . . . . . . . . . . . . . . . 5 Reject parts . . . . . . . . . . . . 1

 Total . . . . . . . . . . . . . . . . 45 

UBC's . . . . . . . . . . . . 17

 Auto parts . . . . . . . . . 9

Tools/machinery . . . 5

 Other . . . . . . . . . . . . . .1

Total . . . . . . . . . . 32 

UBC's . . . . . . . . . . . . 29

 Auto parts . . . . . . . . 25

Tools/machinery . . 10

Total . . . . . . . . . . 68 

 UBC's (Al) . . . . . . . . . . . . . . 46 

Auto parts (Al, Mg) Other (Mg) . . . . . . . . . . . . . . 5 

E2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 1. Magnesium recycling flow, 1998, in thousand metric tons contained magnesium. W, withheld to avoid disclosing company proprietary data; UBC is , used beverage cans. 
MAGNESIUM RECYCLING IN THE UNITED STATES IN 1998 

Table 1. Salient statistics for U.S. magnesium scrap in 1998. 

[Values in thousands of metric tons of contained magnesium, 

unless otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.8 

Value of old scrap consumed . . . . . . . . . $72.1 million

Recycling efficiency3 . . . . . . . . . . . . . . . . . 39 percent 

Supply4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 

Unrecovered5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68.2 

New scrap consumed6 . . . . . . . . . . . . . . . . . . . . . . . . 44.6 

New-to-old-scrap ratio7 . . . . . . . . . . . . . . . . . . . . . . 58:42 

Recycling rate8 . . . . . . . . . . . . . . . . . . . . . . . . . 33 percent 

U.S. net exports of scrap9 . . . . . . . . . . . . . . . . . . . . . . . 7.5 

Value of U.S. net exports of scrap . . . . . . . . $22.2 million 

1Magnesium content of products theoretically becoming obsolete in 

the United States in 1998. It excludes dissipative uses. 

2Magnesium content of products that were recycled in 1998. 

3(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported). Changes in stocks of old scrap are 

withheld and not included. 

4Old scrap generated plus old scrap imported. 

5Old scrap supply minus old scrap consumed minus old scrap 

exported. 

6Including new (prompt) industrial scrap, but excluding home scrap. 

7Ratio of quantities consumed, in percent. 

8Fraction of the apparent magnesium supply that is scrap, on an 

annual basis. 

9On the basis of average value in 1998, trade in scrap is assumed to be 

principally old scrap. 

dryer. The resulting powder is purified, concentrated, 

prilled, and dehydrated to produce anhydrous magnesium 

chloride (Kaplan, 1990). 

Electrolytic cells used to recover magnesium from 

either hydrous or anhydrous magnesium chloride differ 

from company to company, and most information about cell 

design and operating conditions usually is not disclosed. 

Essentially, magnesium chloride fed to an electrolytic cell is 

broken down into magnesium metal and chlorine gas by 

direct current at 700°C. Graphite electrodes suspended in 

the bath serve as anodes, and steel rods serve as cathodes. 

Several cell designs are used for producing magnesium that 

differ in electrode positioning and use of a diaphragm for 

separating the electrodes (Strelets, 1977, p. 250-264). After 

the current breaks down the magnesium chloride into chlorine gas and molten magnesium, the metal formed at the 

cathode rises to the surface of the bath where it is guided 

into storage wells. Metal is dipped from the wells and cast 

into pigs. Chlorine and hydrogen chloride gases generated 

at the anodes are collected from the tightly closed cell and 

pumped to a hydrochloric acid plant for recycling or to a 

plant for separating the chlorine and hydrogen chloride. 

E3 

Although not yet in commercial operation, one plant in 

Canada, which was scheduled to open in 2001, is planning 

to use tailings from an asbestos mine that contain serpentinite as a raw material for magnesium metal. Recovery technology involves leaching the material, removing the impurities in several steps, and recovering magnesium by electrolysis (Brown, 1998.) 

Magnesium is also recovered by recycling magnesium 

chloride produced in the manufacture of titanium. Titanium 

is recovered from titanium tetrachloride (TiCl4

) by the Kroll 

process, in which magnesium is used as a reducing agent. 

This reaction produces a pure anhydrous magnesium chloride that can then be fed to an electrolytic cell to convert it 

back to magnesium metal. Electrolytic cells have been 

developed to take advantage of this type of feed. Chlorine 

generated during the magnesium reduction is recycled to 

prepare another batch of titanium tetrachloride. 

USES 

The largest use of magnesium metal is as an alloying 

addition to aluminum to increase the hardness and corrosion 

resistance of the pure metal. The 5000 and 7000 series alloys 

of aluminum contain up to 5.5 percent and 3.5 percent magnesium, respectively. The single largest application for magnesium-containing alloys of aluminum is the aluminum beverage can, which has a magnesium content of about 4.5 percent in the lid (alloy 5181 or 5182) and about 1.1 percent in 

the can body (alloy 3004). Since the early 1980’s, magnesium consumption in this market has grown at an average 

compound annual rate of 3.2 percent. If it were not for significant increases in aluminum recycling, which lower the 

quantity of primary magnesium needed, this rate might have 

been greater. More than 60 percent of aluminum beverage 

cans are recycled annually, which conserves the aluminum 

and magnesium contents of the alloys as well as the energy 

required to produce them (Sirdeshpande, 1990). 

Magnesium and its alloys have structural uses in the 

forms of die-castings, gravity (sand and permanent mold) 

castings, and wrought products. Die-castings are the largest 

structural application for magnesium. U.S. automakers have 

recently introduced such magnesium components as clutch 

housings, headlamp assemblies, grille covers, instrument 

panels, and seat components to reduce vehicular weight. 

The power tool market includes magnesium castings in 

chain saws and lawnmower housings. Die-cast magnesium 

also is used in cellular phone, computer, and video camera 

components. 

The low density of magnesium is especially important 

for gravity-cast military and aerospace applications. Gravity castings are essentially all produced as sand castings; permanent mold and plaster casting represent a small segment 

of the alloy market. Typical applications include air intakes, 

aircraft canopy frames, auxiliary component housings, 

engine frames, helicopter gear housings, and speed brakes. 
E4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES CONSUMPTION OF MAGNESIUM, IN THOUSANDS OF METRIC TONS 

200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

Other 

Transportation 

Nonferrous metal prodution 

Machinery 

Iron and steel foundries 

Iron and steel desulfurization 

Chemicals 

Cans and containers 

19791980198119821983198419851986198719881989199019911992199319941995199619971998 

YEAR 

Figure 2. U.S. magnesium end-use patterns from 1978 through 1998. 

Magnesium is also used in wrought form in such products as extrusions, forgings, sheet, and plate. Applications 

for these products range from bakery racks, hand trucks, 

loading ramps, and tennis rackets to aerospace assemblies, 

computer printer platens, concrete finishing tools, and 

nuclear fuel element containers. 

In the iron and steel industry, magnesium is used as an 

external hot-metal desulfurization agent and in the production of nodular iron. Magnesium’s unique affinity for sulfur 

allows it to be injected into molten iron, where it vaporizes 

and reacts to form magnesium sulfide, which floats to the 

surface as a readily separated phase. This affinity allows the 

steel producer the flexibility to use lower cost raw materials 

while maintaining the ability to produce the high-quality, 

low-sulfur product required for high-strength, low-alloy 

steels. The magnesium used is often derived from low-quality streams or alloy scrap, which is then ground into a 

coarse powder and combined with lime prior to injection in 

the hot metal. Lime blends have been found to provide significantly improved efficiencies based on the magnesium 

required. 

Magnesium, in combination with ferrosilicon, is used 

in the production of ductile (nodular) iron because of the 

ability of magnesium to promote the formation of spherical 

(globular) graphite particles in place of the normal flake 

structure. This results in an iron product that has improved 

toughness and ductility. Two principal applications for ductile iron are in the production of pipe and automotive engine 

and drive train components. 

Magnesium is used as a catalyst for producing certain 

organic chemicals and petrochemicals and as a reducing 

agent for producing other nonferrous metals, such as beryllium, hafnium, titanium, uranium, and zirconium. Anodes of 

magnesium are frequently used for the cathodic protection 

of iron and steel, particularly in underground pipe and water 

tanks, as well as water heaters and marine applications. 

Magnesium also has smaller applications in the graphic arts 

(as photoengraving plates), pyrotechnics, and alloys other 

than aluminum. 

Data for magnesium metal consumption are reported to 

the U.S. Geological Survey (USGS) from an annual canvass 

of magnesium consumers in the categories that are detailed 

above. These data then are extrapolated to derive end-use 

consumption patterns. According to extrapolations of these 

data by the USGS, the consumption pattern for magnesium 

metal in 1998 in the United States was transportation, 35 

percent; cans and containers, 24 percent; iron and steel 

desulfurization, 13 percent; machinery, 12 percent; iron and 

steel foundries for nodular iron, 2 percent; nonferrous metal 

production, 1.5 percent; chemicals, 0.5 percent; and other 

uses, 12 percent. Figure 2 shows magnesium end-use data 

for a 20-year period. 

Because of the types of applications for magnesium, it 

is primarily used in developed nations. According to data 
MAGNESIUM RECYCLING IN THE UNITED STATES IN 1998 E5 

DOLLARS PER METRIC TON 

5,000


4,500


4,000


3,500


3,000


2,500


2,000


Jan. Jul. Jan. Jul. Jan. Jul. Jan. Jul. Jan. Jul. Jan. Jul. Jan. Jul. 

'92 '92 '93 '93 '94 '94 '95 '95 '96 '96 '97 '97 '98 '98 

DATE 

Figure 3. Average U.S. spot Western magnesium prices. (Source: Platt’s Metals Week.) 

published by the International Magnesium Association 

(1999) that detail world magnesium shipments by geographic area (excluding China and countries formed from 

the former Soviet Union), most magnesium was consumed 

in North America (58 percent) and Europe (27 percent) in 

1998. Magnesium consumption in aluminum alloying and 

die-casting, which are the two principal end uses in all geographic areas, is about even in North America and Europe, 

and aluminum alloying dominates in Asia and Africa 

(greater than 70 percent). In South America, die-casting 

shipments are slightly larger that those for aluminum alloying, although this geographic area does not represent significant magnesium consumption. 

PRICES 

During 1998, the average U.S. spot Western price did 

not fluctuate significantly and was $1.57 per pound at 

yearend. The price was at its highest level at the beginning 

of the year at $1.65 per pound and dropped slightly throughout 1998. Figure 3 shows the trends in magnesium prices 

from 1992 through 1998. 

The sharp increase in the magnesium price from 1994 

through 1995 was caused by the institution of an investigation of magnesium dumping from China, Russia, and 

Ukraine, which stopped imports of magnesium from these 

countries into the United States during the investigation. 

Imports of magnesium from Canada already had been 

eliminated by the imposition of antidumping and countervailing duties in 1992. As demand increased during this 

time, the largest sources of imported magnesium were cut 

off, which led to a significant run-up in prices. At its highest level from September to November 1995, the magnesium price climbed to about $2.17 per pound. Final 

antidumping determinations for magnesium from China, 

Russia, and Ukraine were set in April 1995. Because the 

antidumping duty on Russian magnesium was established 

at 0 percent for all the large producers (as long as they 

imported the magnesium through specified importing 

companies), magnesium could again be imported from 

Russia, which had been the United States’ largest magnesium supplier; as a result, prices declined sharply 

(Kramer, 1999). 

SOURCES OF MAGNESIUM SCRAP 

New magnesium-base scrap typically is categorized 

into one of four types. Type I is high-grade scrap, generally 

material such as gates, runners, and drippings from die-casting operations that is uncontaminated with oils. Types II, III, 

and IV are lower graded materials. Type II is oil-contaminated scrap, type III is dross from magnesium-processing 

operations, and type IV is chips and fines. The most desirable type of scrap is type I. Most of the type I scrap is generated during die-casting of magnesium alloys. This scrap is 

either reprocessed at the die-casting facility or sold to a 

scrap processor. The other types of scrap either are sold to a 

scrap processor or are used directly in steel desulfurization, 

which is a dissipative application. 

Old magnesium-base scrap, or postconsumer scrap, 

consists of such material as automotive parts, helicopter 

parts, lawnmower decks, used tools, and the like. This scrap 

is sold to scrap processors. 

In addition to magnesium-base scrap, significant quantities of magnesium are contained in aluminum alloys that 

also can be recycled. Although some magnesium is lost in 

scrap processing, a significant quantity of the magnesium is 
E6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

recycled with the aluminum alloy. New aluminum-base 

scrap that is recycled consists, in descending order of 

importance, primarily of solids, borings and turnings, dross 

and skimmings, and other material, which includes foil and 

can-stock clippings. Because the main aluminum product 

that contains magnesium is beverage cans, the principal 

magnesium-containing aluminum-base scrap is can scrap 

skeleton from lids and can sheet clippings. This represents 

about one-half of the overall magnesium-containing aluminum-base scrap. 

Old aluminum-base scrap consists of a variety of materials, but the most important magnesium-containing component is used aluminum beverage cans (UBC’s). Because of 

the high recycling rate (about 63 percent in 1998), UBC’s 

represent about three-quarters of the magnesium-containing, old aluminum-base scrap that is reprocessed. The magnesium in old and new aluminum-base scrap is not separated from the aluminum alloy when it is recycled; rather, it is 

retained as an alloying component. Therefore, the magnesium recycling industry consists of three main components—old and new magnesium-base scrap, UBC’s, and 

new aluminum-base scrap. In some cases, the new and old 

aluminum-base scraps are recycled together, but for this 

analysis, they are considered separately. 

Table 1 is the basis for the data shown in figure 1. Definitions of the terms used in the table are detailed in the 

appendix. Data on old and new magnesium-base scrap consumed are reported to the USGS annually by the magnesium consumers and are published in the USGS Minerals 

Yearbook series. Data on old and new aluminum-base 

scrap are reported to the USGS by means of a monthly survey of aluminum-scrap-processing firms; various factors 

are applied to the aluminum scrap to estimate the magnesium content. Trade data for magnesium waste and scrap 

are collected by the U.S. Census Bureau and reported in 

the Minerals Yearbook series. 

To determine the quantity of old scrap available to be 

recycled, data for old scrap generated are estimated by 

determining the lifetimes of various magnesium-containing 

products, combined with the end-use data, and estimated for 

the year that the product was produced. For example, the 

average life of a magnesium-containing automobile component was estimated to be 10 years. Because the magnesium 

consumed in transportation was determined to be 36,000 

metric tons (t) in 1989 (10 years prior to the study period of 

1998), this is the quantity of material that is included in the 

“old scrap generated” figure, which includes magnesium 

contained in the magnesium- and aluminum-base alloys that 

are used in transportation. The average life of an aluminum 

beverage can is less than 1 year, so the quantity of magnesium used in beverage cans in 1997 (46,000 t) was estimated to be the quantity of old scrap generated. For machinery 

and tools, the lifetime is estimated to be 10 years; so the 

quantity of old scrap generated was estimated to be the 

quantity used in 1989, or 17,000 t. The “other” shown in figure 1 is material such as computer parts, magnesium engraving plates, and sporting goods. An estimated 5-year life was 

assumed for these products; these types of products also 

were assumed to represent about one-half of the total 

“other” end uses. Therefore, the quantity of these materials 

that were estimated to be available for recycling was onehalf the “other” end use in 1994, or about 5,000 t. 

DISPOSITION OF MAGNESIUM SCRAP 

Old scrap consists of magnesium-containing products 

that have been discarded or have become obsolete. About 42 

percent of old magnesium scrap generated is from UBC’s 

(fig. 1). UBC’s consist of aluminum alloys in which the 

magnesium is recycled along with the aluminum content. 

The second largest source of old magnesium scrap (35 percent of the total) is automobile components. These consist 

of magnesium- and aluminum-base alloys. As with UBC’s, 

the magnesium content is recycled along with the aluminum 

content of the aluminum alloys. The magnesium-base scrap 

is recycled separately. Of the old scrap that was available for 

recycling in 1998, about 63 percent of the magnesium was 

unrecovered and probably ended up in landfills. A significant portion of the magnesium in aluminum-base scrap was 

lost to the environment, most probably in landfills as well, 

during processing. 

RECYCLING EFFICIENCY 

As shown in table 1, 39 percent of the old magnesium 

scrap generated is recycled, much of which comes from 

recycling UBC’s. UBC’s have a well-established collection 

mechanism that reaches directly to the consumer; many 

municipalities collect cans at the curbside, thus making 

recycling convenient. Making recycling easy for the consumer generally results in a high recycling rate; the UBC 

recycling rate in 1998 was 62.8 percent (Aluminum Association Inc., 1999a). Many of the magnesium components that 

are not recycled, however, are not recycled because they are 

used in consumer goods that do not have a well-established 

recycling collection mechanism. Many items, such as hand 

tools, are discarded in landfills when they become unusable. 

If the magnesium component is part of a larger item, such as 

an automobile, the magnesium part may not be separated 

when the item is recycled because it represents an insignificant portion of the total weight; therefore, the magnesium 

content generally is not recovered during the recycling 

process. The magnesium may be oxidized and become 

entrapped in the fines or dross from recycling and may be 

discarded. 

Of the total magnesium supply in 1998, about 33 percent came from recycled new and old scrap. Although this 

rate was lower than that for such materials as iron and steel 

and lead, it is comparable to those of copper and nickel 

(Papp, 1999, p. 62.14-62.15). One factor that has a significant effect on the overall recycling rate is the quantity of 
MAGNESIUM RECYCLING IN THE UNITED STATES IN 1998 

magnesium that is used in dissipative applications, which 

are defined as uses in which the metal is dispersed or scattered, thus making it exceptionally difficult and costly to 

recycle. Approximately 25 percent of the magnesium that 

was consumed in 1998 was used in dissipative applications, 

which included, in descending order of importance, iron 

and steel desulfurization, sacrificial anodes, chemical manufacture, and nodular iron. Inclusion of the magnesium 

used in these types of applications in the overall magnesium supply makes the magnesium recycling rate appear to 

be artificially low. 

The recycling of the magnesium content in aluminum 

alloys is not likely to increase significantly unless more 

communities introduce curbside recycling programs. As the 

magnesium content of automobiles increases and magnesium is used in larger parts, these components will be easier to separate from the junked automobile, and the recycling 

rate for old scrap is likely to increase. In addition, with the 

production of greater numbers of magnesium alloy die-castings, more new scrap will be generated than was produced 

with the 1998 consumption pattern; therefore, new magnesium-base scrap recycling also is likely to increase. 

INFRASTRUCTURE OF MAGNESIUM 

SCRAP 

LOCATIONS OF FACILITIES 

In 1998, three companies produced 106,000 t of primary magnesium metal. Dow recovered magnesium from 

seawater at a 65,000-metric-ton-per-year (t/yr) plant in 

Freeport, Tex., MagCorp recovered magnesium from brines 

from the Great Salt Lake at a 40,000-t/yr plant in Rowley, 

Utah, and Northwest Alloys recovered magnesium from 

dolomite at a 40,000-t/yr plant in Addy, Wash. Dow closed 

its plant in November 1998. Because each of these plants 

uses a different magnesium-recovery process, data on processing wastes are plant specific and cannot be generalized. 

Magnesium not recovered in the electrolytic process is 

returned to either the sea (in the case of seawater) or the 

solar evaporation ponds (in the case of the Great Salt Lake 

brines). Northwest Alloys generates significant quantities of 

waste from its magnesium processing. In 1997, the waste at 

the plant site was estimated to be about 109,000 t; additional material was in storage facilities and warehouses. 

Although some of the material needs to be disposed in hazardous waste landfills, Northwest Alloys was planning to 

treat and then market some of the material as fertilizer (Wilson, 1997). In addition, magnesium-base scrap, which 

includes such material as off-specification products, is generated at each of these facilities; details on the quantities of 

scrap recycled, however, are not available. 

Magnesium-base-scrap recycling plants are located 

throughout the United States, but the largest percentage of 

capacity is located in the Midwest. Many of the magnesiumproduct-manufacturing capabilities are located in this area, 

E7 

and the recycling plants are located near the scrap-generation facilities; in particular, the magnesium die-casting 

industry. Because some magnesium-base-scrap recycling 

plants also recycle aluminum, the magnesium recovered in 

the magnesium portion of the recycling operation may be 

used as an alloying ingredient in some secondary aluminum 

alloys. 

Magnesium-base-scrap recycling plants are located 

throughout the United States, but the largest percentage of 

capacity is located in the Midwest. Many of the magnesiumproduct-manufacturing capabilities are located in this area, 

and the recycling plants are located near the scrap-generation 

facilities; in particular, the magnesium die-casting industry. 

Because some magnesium-base-scrap recycling plants also 

recycle aluminum, the magnesium recovered in the magnesium portion of the recycling operation may be used as an 

alloying ingredient in some secondary aluminum alloys. 

Table 2 lists information on some of the larger magnesium-base scrap recyclers. This list covers only those that 

recycle magnesium-base scrap, not aluminum-base scrap. 

TRADE 

In 1998, about 12,000 t of magnesium waste and scrap 

was exported, almost all of which went to Canada. The 

magnesium exported to Canada most likely went to Norsk 

Hydro Canada Inc., which had a recycling plant associated 

with its primary production facility in Becancour, Quebec. 

The average value of this scrap was about $2,300 per metric 

ton. On this value basis, more than 90 percent of the scrap 

exported was estimated to be old scrap. Of the total quantity of magnesium and magnesium alloys that were exported 

in 1998, scrap represented about 37 percent, on a grossweight basis. 

Imports for consumption of magnesium waste and 

scrap in 1998 totaled about 6,000 t. Approximately 47 percent of this material came from Canada, 9 percent from the 

United Kingdom, and 8 percent from China. The average 

value of this material was about $1,400 per metric ton. On 

the basis of the value of individual shipments during the 

year, 4,000 t was estimated to be old scrap, and 2,000 t, new 

scrap. Of the total imports for consumption of magnesium 

and magnesium alloys, scrap represented about 7 percent, 

on a contained-weight basis, in 1998. 

PROCESSING OF MAGNESIUM SCRAP 

STRUCTURAL MAGNESIUM-BASE PRODUCTS 

In making magnesium alloy die-castings, about 50 percent of the material ends up as a finished product, and the 

remainder as new scrap. Of the scrap generated in the diecasting process, about 80 percent ends up as trimmings; 8 

percent, as dross; 7 percent, as chips; 4.5 percent, as reject 

parts; and the remaining 0.5 percent, as a slurry, which is 

probably lost (Albright, 1993). For magnesium extrusions, 

about 75 percent of the magnesium ends up in the product, 
E8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Table 2. Major U.S. magnesium-base scrap processors. 

[Metric tons per year. NA, Not available] 

Company City State Product Type of scrap processed Capacity 

Alabama Cathodic Foley Ala. Magnesium ingots (mostly for New die-cast and old 1

17,000 

Metals Inc. aluminum alloying) and anodes. magnesium base. 

Garfield Alloys Inc. Cleveland Ohio Magnesium ingots, anodes, New (types II, III, IV) 13,600 

powder, and granules. 

Garfield Alloys Inc. Bellevue Ohio NA New (type I)-.5 

15,000 

(MagReTech Inc.). 

IMCO Recycling Inc. Sapulpa Okla. Magnesium ingot and anodes Dross and old magnesium NA 

base. 

Reactive Metals W. Pittsburgh Pa. Desulfurization reagents Dross NA 

and Alloys Corp. 

Rossborough Walkerton Ind. Desulfurization reagents Chips NA 

Manufacturing Co. 

L.P. 

Spectrulite Madison Ill. Magnesium ingots New die-cast 15,000 

1

Closed in 2000. 

and the remainder is new scrap (mostly chips), much of 

which is recycled internally (Barnes and Barnes, 1994). 

Extrapolating from data collected by the USGS and these 

factors, approximately one-third of the magnesium that is 

used to fabricate structural products (castings and wrought 

products) ends up as new scrap, which is either reprocessed 

or used directly in dissipative applications, such as steel 

desulfurization and sacrificial anodes. 

Magnesium scrap arrives at the recycler either loose 

on a dump trailer or in boxes on a van-type trailer. Sorting 

the magnesium-base scrap correctly is crucial to producing 

a product that meets specifications. Because magnesium 

and aluminum closely resemble each other, a load of magnesium scrap may contain some aluminum scrap as well. 

The scrap is visually inspected, and one of the ways to separate the magnesium from the aluminum scrap is by 

scratching the metal with a knife. Magnesium tends to 

flake, whereas the softer aluminum tends to curl. After 

being separated from the aluminum-base scrap and any 

other foreign material, the magnesium scrap is sorted 

according to alloy. 

In melting, sorted scrap is charged to a steel crucible, 

which is heated to 675°C. As the scrap at the bottom begins 

to melt, more scrap is added. The liquid magnesium at the 

bottom is covered with a flux or inhibitive gas to control 

surface burning. After any alloying elements are added, 

such as aluminum, manganese, or zinc, and melting is complete, molten magnesium is transferred to ingot molds by 

hand ladling, pumping, or tilt pouring (Wentz and Ganim, 

1992). 

In addition to melting, magnesium scrap may be recycled by direct grinding of the scrap into powder for iron and 

steel desulfurization applications. This method is limited to 

using only specific types of clean scrap. Drosses and other 

contaminated scrap are not used because they can introduce 

impurities into the finished product, and these types of scrap 

can increase the danger of fire in the direct grinding (Dahm, 

2000). 

USED BEVERAGE CAN RECYCLING 

In UBC recycling, most of the cans are converted into 

body stock (AA3004) after they are melted and delaquered. 

Much of the magnesium remains with the recycled can, but 

some is lost during reprocessing. A simplified diagram of 

the magnesium portion of UBC recycling is shown in figure 

4. Data for this figure were determined from the content and 

recovery rates shown in table 3 and by using a 63-percent 

UBC recycling rate for 1998. Because UBC scrap is recycled almost exclusively into aluminum cans, the magnesium 

recovered from this product can be recycled as many times 

as the aluminum cans are recycled. 

In recycling UBC’s, the UBC stream is blended with virgin material in the production of aluminum cans. The losses 

shown in figure 4 may come from either the UBC or the virgin material (except for those in the melting and delacquering 

stage); once the streams are combined, the two are indistinguishable. For convenience, these losses are shown from the 

old scrap component in figure 1. A more detailed discussion 

of UBC recycling is presented by Jenkins and Robertson 

(2000, p. 1007-1027). 
MAGNESIUM RECYCLING IN THE UNITED STATES IN 1998 E9 

Primary Mg 

New sheet skeleton 

27.0 0.6 8.9 Process loss

Remelt loss 

28 

3.2 

5.4 

Melting and delacquering Sheet (AA3004) (75%) 

End and tab (AA5182) (25%) 

UBC's 

Al + elements 

19.1 

44.4 

Cans to consumer 

Remelt loss 

1.1


New tab/end skeleton


Figure 4. Simplified used beverage can processing, in thousands of metric tons of contained 

magnesium. UBC’s. used beverage cans. Adapted from Bowman, 1983. 

ALUMINUM-MAGNESIUM ALLOYS 

Magnesium-containing scrap also is generated when 

aluminum-magnesium alloys are fabricated. The USGS 

estimates that most of these aluminum-magnesium 

alloys are used in packaging (aluminum beverage cans), 

transportation, and machinery applications, in descending order of use. The Aluminum Association, Inc. 

(1999b, p. 22-26), collects data on product form shipments by major application. In addition, the Aluminum 

Association completed a life-cycle study that determined 

the quantity of scrap generated in various fabrication 

operations, which included shape casting, extruding, and 

hot and cold rolling, in descending order of scrap generation. For aluminum shape casting, about 45 percent of 

the input material ends up as new scrap; for extrusion, 30 

percent; for hot rolling, 17 percent; and for cold rolling, 

16 percent. In addition, some material ends up as 

residues, which are also recycled (Aluminum Association Inc., 1998, p. 4-14 to 4-17.) Based on the above, 

information about the quantity of scrap generated from 

aluminum beverage can production, and USGS estimates 

of quantities of magnesium used in aluminum alloys in 

each application, approximately 30 percent of the magnesium in aluminum alloys becomes scrap, and 8 percent 

is lost to the environment. 

In aluminum can production, 24.2 percent of the body 

stock ends up as skeleton, and 16.4 percent of the tab and 

end stock ends up as skeleton scrap (Bowman, 1983). Of 

this scrap, 100 percent is assumed to be returned to the sheet 

producer for reclaiming. Approximately 5 percent of the 

cans produced are projected to be spoilage; this material is 

assumed to be sent to a secondary aluminum smelter where 

the magnesium component most likely is lost (Sanders and 

others, 1990, p. 196). 

Table 3. Used beverage can scrap melting data. 

[In percent. From Bowman, 1983] 

Type Metal Magnesium 

recovery content 

Body stock skeleton 

(AA3004, 1.05-percent Mg) 80 0.95 

End and tab stock skeleton 

(AA5182, 4.50-percent Mg) 90 3.4 

Recycled beverage cans 

(1.9-percent Mg) 90 1.3 

TITANIUM PRODUCTION 

Magnesium also can be recovered in the production of 

titanium. In the Kroll process to produce titanium metal, 

TiCl4 is reacted with magnesium metal to form titanium metal 

and magnesium chloride in a batch reactor. After the titanium 

is separated from the magnesium chloride, the magnesium 

chloride can be reduced in an electrolytic cell to form magnesium metal and chlorine gas. The magnesium metal can 

then be reused to react with a new batch of TiCl4

. Approximately 125 percent of the stoichiometric quantity of magnesium is needed to assure complete reduction of the TiCl4

, and 

if this is recycled, then about 0.2 to 0.5 t of magnesium per 

metric ton of titanium produced is needed to make up for 

losses. Because production of magnesium is very energy 

intensive, recycling of magnesium may be dependent on 

energy costs, which vary from plant to plant (Poulsen and 

Sprayberry, 1992). This type of magnesium recycling is analogous to home scrap recycling. Because titanium sponge production data in the United States are withheld, data on the 

quantity of magnesium that is recycled in titanium plants are 

also withheld and, therefore, are not included in figure 1. 
E10 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

OUTLOOK 

If magnesium use in the automobile industry continues 

to grow at the rapid pace that it has in the past few years, 

then this growth could have significant immediate and longterm effects for the magnesium recycling industry worldwide. The immediate effect would be a huge increase in the 

quantity of new scrap generated because about 50 percent of 

the weight of the input material becomes new scrap. As a 

result of this anticipated increase in new scrap generation, 

companies are planning new magnesium recycling plants or 

they are expanding existing capacity. The principal longterm effect is that after an automobile is junked, the magnesium-containing parts may be removed from the automobile 

and recycled. These additional magnesium-containing parts 

would result in additional quantities of old scrap as a source 

of supply. The projected increase in the use of magnesium 

in this application has prompted other countries to install 

additional magnesium recycling capacity. New magnesium 

recycling plants have been planned for Germany and Japan, 

and increases in capacity at existing plants were announced 

for Germany, Japan, and the United Kingdom (Kramer, 

2001). 

Potential legislation to regulate the use of sulfur hexafluoride (SF6

) may affect the magnesium industry as a 

whole, which includes the magnesium-recycling sector. 

International concern over global warming has focused 

attention on the long atmospheric life of SF6, which has 

about 23,800 times the global warming potential of carbon 

dioxide. Although the primary use of SF6 is as a dielectric in 

electrical transmission and distribution systems, it is also 

used as a cover gas in casting molten magnesium. 

Fugitive emissions of SF6 occur from leaks in and servicing of substations and circuit breakers, especially from 

older equipment. The U.S. Environmental Protection 

Agency (EPA) (1999) estimated that emissions from this 

source increased to 7.0 million metric tons (Mt) of carbon 

equivalents in 1997; this was a 25-percent increase from 

those in 1990. Estimated emissions from primary magnesium production and magnesium casting were 3.0 Mt of 

carbon equivalents in 1997; this was an increase of 76 percent since 1990 (EPA, 1999). In 1998, the EPA began a collaborative effort with the U.S. magnesium industry to 

improve manufacturing processes and gas-handling practices in an effort to reduce emissions of SF6 (EPA, 1998). 

The magnesium industry itself is investigating the use of 

other gases as a substitute for SF6. For example, researchers 

at Australia’s Commonwealth Scientific and Industrial 

Research Organisation (CSIRO) have investigated a number of alternatives that are more environmentally friendly 

than SF6

, one of which is very promising. SF6 can be 

replaced with the hydrofluorocarbon 1,1,1,2 tetrafluoroethane (HFC-134a) with only minor modifications to gas 

delivery systems. HFC-134a, which is a refrigerant gas 

commonly used in car air conditioners, is not toxic, corrosive, or flammable and does not contribute to ozone depletion. According to CSIRO (2000), replacing SF6 with HFC134a has the following advantages: 

•	 HFC-134a has a global warming potential of only 

1,300 times the global warming potential of carbon 

dioxide, or 18 times less than that of SF6 

•	 HFC-134a is only about one-third of the cost of SF6; 

HFC-134a is more effective than SF for magnesium 6 

melt protection 

• 	HFC-134a has the ability to extinguish a magnesium 

fire once started, whereas SF6 will not (Commonwealth 

Scientific and Industrial Research Organisation, 2000). 
MAGNESIUM RECYCLING IN THE UNITED STATES IN 1998 

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E11 

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in fertilizer: web site at http://www.seattletimes.com/. 

(Accessed December 9, 1999.) 
E12 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it 

exceptionally difficult and costly to recycle. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

price. Based on the unit value of zinc in materials.


primary zinc. Zinc derived from ore.


recycling. Reclamation of a metal in usable form from scrap


or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 
U.S. Department of the Interior

U.S. Geological Survey

Lead Recycling in the United States in 1998 

By Gerald R. Smith 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–F

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES

III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


History and Use Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Global Geologic Occurrence of Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Lead Production Process and Global Production . . . . . . . . . . . . . . . . . . . . . . . 4

Lead Market Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Sources of Lead Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Old Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Disposition of Lead Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Infrastructure of Lead Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Battery Scrap Collection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Trade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Processing of Lead Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Spent Battery Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Battery Fabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Outlook for Lead Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

FIGURES 

1. Flow diagram showing U.S. lead materials flow in 1998 . . . . . . . . . . . . . . . . . . . . . F2

2. Graph showing U.S. lead consumption in batteries from 1978 through 1998 . . . . . . 5

3. Graph showing U.S. lead consumption, by end-use sector, nonbattery uses


from 1978 through 199 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

TABLES 

1. Salient statistics for U.S. lead scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

kilometer (km) 

inch (in.) 

Length 

0.6214 

25.4 

mile 

millimeter 

Volume 

cubic foot (ft3

) 0.02832 cubic meter 

Mass 

gram (g) 

kilogram (kg) 

kilogram (kg) 

metric ton (t, 1,000 kg) 

troy ounce (troy oz) 

0.03527 

2.205 

32.1507 

1.102 

31.10 

ounce avoirdupois 

pound avoirdupois 

troy ounce 

short ton (2,000 pounds) 

gram 

Pressure 

pound force per square inch 

atmosphere (atm) 

6.895 

101.3 

kilopascal 

kilopascal 

For temperature conversions from degrees Celsius (°C) to degrees Fahrenheit (°F), use the following: 

°F = (1.8 × °C) + 32 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Lead Recycling in the United States in 1998 

By Gerald R. Smith 

ABSTRACT 

This materials flow study includes a description of lead 

supply and demand factors for the United States to illustrate 

the extent of lead recycling and to identify recycling trends. 

Understanding the system of materials flow from source to 

ultimate disposition can assist in improving the management of the use of natural resources in a manner that is compatible with sound environmental practices. The quantity of 

lead recycled in 1998, as a percentage of apparent lead supply, was estimated to be about 63 percent, and recycling 

efficiency, to be 95 percent. Of the total lead consumed in 

products for the U.S. market in 1998, an estimated 10 percent was consumed in products in which the lead was not 

readily recyclable. 

INTRODUCTION 

Figure 1 and table 1 provide data on the use of lead in 

the United States in 1998. The sources of lead supply and 

the distribution of these supplies are quantified in this illustration so that specific information on recycling, including 

lead scrap recycling efficiency and lead scrap recycling rate 

(see appendix) can be determined. As an introduction prior 

to specific discussion of the components of figure 1, the following background on lead, including its history, important 

uses and use trends, geological occurrence, production 

processes, and market prices, is discussed. 

HISTORY AND USE PATTERNS 

Lead is a very corrosion-resistant, dense, ductile, and 

malleable blue-gray metal that has been used for at least 

5,000 years. Early uses of lead included building materials, 

pigments for glazing ceramics, and pipes for transporting 

water. The castles and cathedrals of Europe contain considerable quantities of lead in decorative fixtures, roofs, pipes, 

and windows (Shea, 1996, p. 1). Lead scrap has represented 

a portion of lead supply in the United States since the 1800s. 

The earliest known report of consumption of lead scrap was 

between 1867 and 1889 when about 11,000 metric tons (t) of 

lead scrap was imported to the United States for unspecified 

uses (Kirchhoff, 1894). Actual U.S. production of lead from 

scrap was first reported in 1907. In the following 2 years, 

about 77,000 t of recycled lead was recovered (Siebenthal, 

1911, p. 187). The recovery of lead from scrap increased significantly in the United States during the next 18 years, and 

by 1927, nearly 252,000 t of lead had been recovered from 

scrap; this represented an estimated 27 percent of the total 

refined lead consumed (Smith, 1930, p. 341). By 1980, the 

quantity recovered had reached 675,000 t, which was about 

63 percent of the total refined lead consumed, and by 1998, 

it had risen to 1.12 million metric tons (Mt), which was 69 

percent of consumption (Rathjen, 1981, p. 480; Smith, 

2000). 

Prior to the early 1900s, uses of lead in the United 

States were primarily for ammunition, brass, burial vault 

liners, ceramic glazes, leaded glass and crystal, paints or 

other protective coatings, pewter, and water lines and pipes. 

The advent of the electrical age and communications, 

which were accelerated by technological developments in 

World War I, resulted in the addition of bearing metals, 

cable covering, caulking lead, solders, and type metal to the 

list of lead uses. With the growth in production of public 

and private motorized vehicles and the associated use of 

starting-lighting-ignition (SLI) lead-acid storage batteries 

and terne metal for gas tanks after World War I, demand for 

lead increased. Most of these uses for lead continued to 

increase with the growth in population and the national 

economy. Contributing to the increase in demand for lead 

was the use of lead as radiation shielding in medical analysis and video display equipment and as an additive in gasoline, which peaked in the late 1970s when environmental 

bans on leaded gasoline were introduced. 

Figures 2 and 3 show the trends in consumption of lead 

in the United States since 1978. By the mid-1980s, a significant shift in lead end-use patterns had taken place. The 

demand for lead in SLI-type batteries grew rapidly, and this 

growth continued into the 1990s (fig. 2). In addition, the 

demand for lead in non-SLI battery applications also grew. 

Non-SLI battery applications include motive sources of 

power for airport ground equipment, industrial forklifts, 

mining equipment, and a variety of nonroad utility vehicles, 

as well as stationary sources of power in uninterruptible 

electric power systems for hospitals and for computer and 

telecommunications networks, and load-leveling equipment 

for electric utility companies. The use of lead in nonbattery 

products declined as battery demand increased (fig. 3). 

F1 
DOMESTIC SUPPLY OF UNWROUGHT DISTRIBUTION OF DOMESTIC SUPPLY OF UNWROUGHT

PRIMARY AND SECONDARY LEAD PRIMARY AND SECONDARY LEAD 

Release of industry and

Government stocksof refined metal:Government . . . . . 50

63 

Imports of refined

lead metal . . . . 267 

267 

Domestic productionof primary leadmetal . . . . . . . . . . 343 

343 

1 7 Home

scrap .1 Processing

losses . . 7

Domestic productionof secondary leadmetal . . . . . . . 1,120

Old scrap consumed:

Batteries . . . . .1,010

Other . . . . . . . . . 42

1,060 

55 

New (prompt) scrap consumed:

Drosses and residues . . . . . 46

9

Old scrapunrecovered . . .63

Old scrapexported . . .103 63 

103 

7 Old scrap

stockdecrease . . 7 

Old scrapsupply . .1,230

Old scrap generated:

Batteries

Other . . . . . . . . . 50

1,220 

1,790 

Lead productsin reservoirnetchange . . .+300 

Exports of refinedlead metal . . . . 24

Fabrication . . . . 1,770 

Net exports ofsemifabricatedproducts . . . . 7 

Dissipativeuses . . .178 

Lead productsto U.S.market . . .1,700 

Homescrap . .5 

New (prompt) scrap generated:

55 

Drosses and residues . . . .46

7 

178 

1,520 

1,700 

5 

1,770

24 

55 

1,060 

1,220 

Industry . . . . . . . . . 13

 Total . . . . . . . . . . 63 

 Solder . . . . . . . . .12 Total . . . . . . . 1,060 

 Copper-base scrap . . . . . . . .  Total . . . . . . . . . . . . . . . . . 55 

. . . . 1,170

 Total . . . . . . 1,220

 Copper-base scrap . . . . . . . 9 Total . . . . . . . . . . . . . . . . 55 

F2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 1. U.S. lead materials flow, in 1998. Vaues are in thousands of metric tons of contained lead and have been rounded to three significant figures. 
LEAD RECYCLING IN THE UNITED STATES IN 1998	 F3 

Table 1. Salient statistics for U.S. lead scrap in 1998. 

[Values in thousands of metric tons of contained lead, unless 

otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,220 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,060 

Value of old scrap consumed . . . . . . . . . $263 million

Recycling efficiency3 . . . . . . . . . . . . . . . . . 95 percent 

Supply4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,230 

Unrecovered5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 

New scrap consumed6 . . . . . . . . . . . . . . . . . . . . . . . . . . 55 

New-to-old-scrap ratio7 . . . . . . . . . . . . . . . . . . . . . . . 5:95 

Recycling rate8 . . . . . . . . . . . . . . . . . . . . . . . . . 63 percent 

U.S. net exports of scrap9 . . . . . . . . . . . . . . . . . . . . . . 103 

Value of U.S. net exports of scrap . . . . . . . . $26.8 million 

1Lead content of products theoretically becoming obsolete in the 

United States in 1998. It excludes dissipative uses. 

2Lead content of products that were recycled in 1998. 

3(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported plus any old scrap stock decrease or 

minus any old scrap stock increase). 

4Old scrap generated plus old scrap imported plus old scrap stock 

decrease. 

5Old scrap supply minus old scrap consumed minus old scrap exported minus old scrap stock increase. 

6Including prompt industrial scrap, but excluding home scrap. 

7Ratio of quantities consumed, in percent. 

8Fraction of the lead apparent supply that is scrap, on an annual basis. 

It is defined as (consumption of old plus consumption of new scrap) divided 

by apparent supply (see appendix), measured in weight and expressed as a 

percentage. 

9Trade in scrap is assumed to be principally old scrap. Net exports are 

exports of old scrap minus imports of old scrap. 

Much of the decline in nonbattery use of lead was a 

result of the U.S. lead consumers' compliance with environmental regulations that significantly reduced or eliminated 

the use of lead in products that included gasoline, paints, 

solders, and water systems. Data for consumption of lead 

used as chemical additives in gasoline from 1987 through 

1995 were estimated. The U.S. Environmental Protection 

Agency (EPA) issued a direct final rule that prohibits the 

use of such additives in highway vehicles effective January 

1, 1996 (U.S. Environmental Protection Agency, 1996). By 

1998, the total demand for all types of lead-acid storage batteries represented a record high 88 percent of apparent U.S. 

lead consumption. Other significant uses included ammunition (3 percent), oxides in glass and ceramics (3 percent), 

casting metals (2 percent), and sheet lead (1 percent). The 

remainder was consumed in bearing metals, brass and 

bronze billets, covering for cable, caulking lead, extruded 

products, and solders. U.S. lead consumption in 1998 was 

about 29 percent of total world consumption of lead. The 

lead end-use pattern in the remainder of the world, with 

batteries being the predominant end-use sector, was similar 

to that of the United States (International Lead and Zinc 

Study Group, 1999, p. 23-34). 

The domestic demand for refined lead, by industrial 

sector in 1998, was principally in the transportation industry as component material for batteries, fuel tanks, seals, 

solders, and wheel weights and in the communication, construction, electrical, and electronic industries in such products as batteries, cable covering, extruded shapes, pipes, and 

radiation shielding. A small amount of lead also was consumed for use by producers of ceramics, crystal glass, and 

specialized chemicals. 

GLOBAL GEOLOGIC OCCURRENCE OF LEAD 

Conventional deposits of primary lead and zinc are separable into five principal types that are based, for the most 

part, on differences in their geologic environments. The following definitions and descriptions of these deposits are 

from Briskey and Wedow (1986) and J.A. Briskey (U.S. 

Geological Survey, written commun., 2000). 

• 	Volcanic-hosted submarine exhalative massive sulfide 

deposits comprise almost entirely pyrite and pyrrhotite 

(iron sulfides) with varying proportions and amounts of 

sphalerite (zinc sulfide), galena (lead sulfide), chalcopyrite (copper and iron sulfide), and silver-bearing 

minerals. Lists of minerals in this geologic section are 

approximately in order of decreasing abundance. The 

sulfide minerals typically occur as multiple stratiform 

lenses within submarine volcanic rocks and commonly 

overlie or are adjacent to discordant feeder zones that 

contain smaller amounts of these minerals as stringers 

and disseminations in altered volcanic rocks. Large 

examples of these deposits include those found in 

Canada, Cyprus, Japan, Tasmania, and Turkey. 

•	 Sediment-hosted submarine exhalative deposits consist 

of stratiform basinal accumulations that comprise mainly fine-grained pyrite and (or) pyrrhotite, sphalerite, 

galena, sporadic barite (barium sulfate), and minor chalcopyrite interbedded with euxinic marine sediments, 

which include black shales, siltstones, sandstones, 

cherts, dolostones (calcium magnesium carbonate), and 

micritic limestones (calcium carbonate). Large examples of these deposits are found in Australia, Canada, 

Germany, and the United States (Alaska). 

•	 Strata-bound carbonate-hosted deposits, which are commonly referred to as “Mississippi Valley type,” contain 

mostly sphalerite, galena, pyrite, barite, fluorite (calcium fluoride), and chalcopyrite. These minerals typically fill primary and secondary voids developed in favorable beds or horizons within thick sequences of platform 

dolostones and limestones. Important examples of these 

deposits are found in the Mississippi Valley and adjacent 

regions of the United States, which include the Upper 
F4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Mississippi Valley, the tristate region (Kansas-MissouriOklahoma), southeastern Missouri, and the central and 

east Tennessee districts, and are found in the Alps in 

southern Europe, Canada, and Poland. 

•	 Sandstone-hosted deposits typically are strata-bound 

and commonly are stratiform concentrations of mainly 

fine-to-medium crystalline galena with sporadic smaller amounts of sphalerite, pyrite, barite, fluorite, and 

minor chalcopyrite. These minerals usually occur as 

clots and disseminations that in aggregate form multiple, thin, sheetlike ore bodies within marine, terrigenous, and continental sandstones, conglomerates, grits, 

and siltstones. Important examples of these deposits are 

found in Canada, France, Morocco, and Sweden. 

• 	Vein, replacement, and contact metasomatic deposits 

typically comprise coarse crystalline aggregates of 

pyrite, sphalerite, galena, and chalcopyrite, as well as 

a large number of complex base- and precious-metal 

sulfide minerals that include those that contain abundant arsenic and antimony. Most deposits form multiple, tabular-to-podiform, or pipe-shaped ore shoots or 

occur as extensive, highly irregular, branching masses. 

Deposits occur in clusters (districts) that are spatially 

and temporally related to nearby granitic plutons of 

granodioritic or quartz monzonitic composition. Contact metasomatic deposits are restricted mostly to the 

contact aureoles of the plutons. Replacement and contact metasomatic ore bodies typically replace carbonate 

rocks adjacent to the pluton, whereas vein deposits are 

usually open-space fillings in fractures in a variety of 

host rocks. Classic examples of these deposits are 

found in Germany, Japan, Mexico, Peru, and, especially, the Western United States. 

LEAD PRODUCTION PROCESS AND GLOBAL 

PRODUCTION 

The major share of the U.S. mine output of lead in 1998 

was derived from production in Alaska and Missouri. 

Appreciable quantities were also produced from mining 

operations in Colorado, Idaho, and Montana. Cumulatively, 

during the past 200 years, 57 percent of the U.S. mine output 

of lead was from strata-bound carbonate-hosted deposits, 

and 40 percent was from vein, replacement, and contact 

metasomatic deposits. The remaining 3 percent was produced from volcanic-hosted submarine exhalative massive 

sulfide, sediment-hosted submarine exhalative, and other 

deposits (Long, DeYoung, and Ludington, 2000, p. 640). 

Lead is processed from the mined ore to the concentrate 

stage through a series of conventional beneficiation steps. 

After the raw ore is screened, crushed, and ground at the mill, 

it is chemically treated in a flotation process to separate 

metal-containing minerals from the waste rock (tailings) and 

from each other. The resulting lead concentrate is then further 

processed through sintering, smelting, and refining steps to 

produce the pure lead metal. Most of the copper, nickel, and 

other impurities, which include antimony, arsenic, gold, and 

silver, are removed from the lead in a “dross” layer that forms 

on the surface of the melt upon cooling. 

The lead bullion product from the smelting step is then 

processed through several molten refining steps to remove 

the remaining trace impurities, which may include antimony, 

arsenic, bismuth, copper, silver, tellurium, and zinc; this 

process ultimately yields a minimum of 99.97 percent pure 

refined lead. This lead is then cast into various size ingots for 

sale to end-use consumers. In 1998, mine production of lead 

was reported in 44 countries; the top 5 accounted for 68 percent of the world’s total production of 3.1 Mt of lead in concentrates. Australia was the largest producer with 20 percent 

of the world total, followed by China, 18 percent; the United 

States, 16 percent; Peru, 8 percent; and Canada, 6 percent. 

LEAD MARKET PRICES 

Refined lead prices declined throughout most of 1998. 

The average London Metal Exchange and North American 

Producer prices per pound were $0.240 and $0.453, respectively, which were down by $0.043 per pound and $0.013 

per pound, respectively, compared with those of 1997. In 

1998, recycled lead sold for an average $0.483 per pound, 

which was down by $0.012 per pound compared with the 

price in 1997 (Platt’s Metals Week, 1999). The market price 

for whole scrap lead-acid batteries (a principal source of 

lead for recycling) ranged between $0.045 and $0.065 per 

pound, which translated to a lead price of $0.09 to $0.13 per 

pound assuming that the average amount of lead in such batteries is about 50 percent (Worden, 1998). Soft lead scrap 

from other sources averaged $0.195 per pound (American 

Metal Market, 1999). 

In the late 1980s and early 1990s, lead prices generally 

increased as the lead-producing industry continued to adjust 

effectively to environmental regulations imposed a few 

years earlier. After a brief decline, prices rose steadily from 

1992 to 1996 as a result of the increasing demand in the 

replacement automotive battery sector. In 1997 and 1998, 

the price of lead showed some softness owing to 2 consecutive years of moderate temperatures in the more-populated 

regions of the United States that reduced the failure rate of 

automotive-type batteries and the subsequent need for 

replacement batteries. 

SOURCES OF LEAD SCRAP 

Sources of new and old scrap are key features of the 

U.S. lead materials flow diagram that is shown in figure 1. 

Statistical data for the various types of old and new scrap 

processed into refined lead metal for domestic consumption were derived from specific information provided to 

the U.S. Geological Survey (USGS) by the lead recycling 

(secondary) industries. 
LEAD RECYCLING IN THE UNITED STATES IN 1998 F5

200

175

150

125

100

75

50

25

0

CONSUMPTION, IN THOUSANDS OF METRIC TONS

Petroleum chemicals 

Brass and bronze 

Paint and glass pigments 

Solder

Sheet lead 

Nonbattery Uses 

End-Use Sector, 

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 

YEAR

Figure 3. U.S. lead consumption by end-use sector, nonbattery uses from 1978 through 1998. 

Figure 2. U.S. lead consumption in batteries from 1978 through 1998. 
F6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

The domestic supply of primary and secondary refined 

lead, as shown in figure 1, consists of primary and secondary refinery production, net imports of refined lead, sales of 

lead from the Government stockpile, and net releases of 

industry stocks. Data on trade and Government stockpile 

sales were obtained from the U.S. Census Bureau and the 

U.S. Defense National Stockpile Center, respectively, 

through monthly reports issued by the agencies. 

The salient lead scrap statistics discussed in this 

report for calendar year 1998 (table 1) are based primarily upon information received from lead industry producers and consumers through industry surveys submitted to 

the USGS. Statistics received through these surveys provided about 99 percent of the total production of refined 

lead reported and 96 percent of the apparent consumption 

of lead. 

OLD SCRAP GENERATED 

The key component of the lead recycling industry in 

the United States is the reprocessing of spent lead-acid batteries. In 1998, approximately 88 percent of these spent 

batteries were of the SLI automotive type, which had an 

average life of about 4 years; 8 percent were of the motive 

power type, which had an average life of 6 years; and 4 

percent were of the stationary type, which had an average 

life of 10 years (Battery Council International, 1998, p. 3). 

The calculated quantity of old scrap generated in 1998 was 

assumed to have originated from lead consumed in the 

manufacture of batteries of the SLI automotive type in 

1994, the motive power type in 1992, and the stationary 

type in 1988. An estimated 97 percent of all the old lead 

scrap generated in 1998 was from spent lead-acid storage 

batteries. The remainder was from metal sources, such as 

castings, sheet, solders, and miscellaneous fabricated 

parts. 

NEW SCRAP 

The quantity of refined lead recovered from new scrap 

was estimated from the gross weight of purchased drosses 

and residues reported to the USGS as a source of scrap by 

the lead recycling industries. An additional source of new 

lead scrap was that contained in copper-base alloys. New 

scrap consumed in 1998 was estimated to be 55,000 t, or 

about 5 percent of total scrap consumed. 

DISPOSITION OF LEAD SCRAP 

In 1998, recycled lead represented nearly 77 percent of 

refined lead production in the United States. The spent leadacid battery is the dominant source of lead for reprocessing 

by the secondary lead industries. Thus, the efficiency with 

which these batteries are collected, reprocessed, and 

returned to the marketplace in the form of refined lead is of 

prime importance in maintaining the required supply of lead 

in the United States. 

OLD SCRAP RECYCLING EFFICIENCY 

Recycling efficiency shows the relation between what 

is theoretically available for recycling and what is and is not 

recovered. By definition, this relation is the amount of old 

scrap consumed plus old scrap exported divided by the sum 

of old scrap generated and old scrap imported plus or minus 

old scrap stock changes. Each component that is used to 

determine the relation is considered in terms of the recoverable metal content. The recycling efficiency of about 95 percent that was reached in 1998 is consistent with the organized infrastructure that exists in the United States for collection and recovery of lead scrap and, in particular, spent 

lead-acid batteries. 

INFRASTRUCTURE OF LEAD SCRAP 

In 1998, about 98 percent of all recycled lead was produced by 9 companies that operated 17 battery recycling 

plants in Alabama, California, Florida, Georgia, Indiana, 

Louisiana, Minnesota, Missouri, New York, Pennsylvania, 

Tennessee, and Texas. The geographical distribution of these 

plants effectively supports the complete network of spent 

battery sources. Secondary lead production capacity in the 

United States is estimated to be about 1.1 Mt per year. 

BATTERY SCRAP COLLECTION SYSTEM 

An estimated 60 percent to 70 percent of spent leadacid batteries are collected for recycling each year by battery manufacturers through sales agreements with major 

retailers or through reverse distribution systems. The manufacturers typically collect spent batteries from retailers 

when delivering shipments of new lead-acid batteries. 

Retailers accumulate these spent batteries in exchange when 

customers purchase new batteries. Upon collection of the 

batteries from the retailer, the battery manufacturer, in turn, 

arranges to recover the lead content of the batteries through 

tolling agreements with secondary lead smelters. This lead 

is then returned to the manufacturer as feedstock for the production of new batteries. If the battery manufacturer also 

owns a secondary smelter, then the tolling step is eliminated. The remaining 30 percent to 40 percent of spent batteries are collected by scrap dealers. These dealers collect from 

sources other than large retailers, which include small 

retailers, service stations, and junk yards, and subsequently 

offer the batteries for sale on the open market. 

TRADE 

As a net exporter of lead scrap, the United States sent 

103,000 t abroad in 1998; about 91 percent went to Canada. 

Other places that received appreciable quantities of lead 

scrap from the United States included Belgium, China, 

Hong Kong, India, Japan, Mexico, Sweden, Taiwan, and the 

United Arab Emirates. The exported scrap was principally in 

the form of battery and nonbattery metal scrap, which 
LEAD RECYCLING IN THE UNITED STATES IN 1998 

included approximately 5,000 t of lead contained in whole 

spent batteries. The remaining scrap (about 9 percent) was 

exported in the form of ash and residues. Exports of lead 

scrap represented about 39 percent of the total exports of 

lead-containing materials, which included base bullion, concentrates, and wrought and unwrought lead and lead alloys. 

PROCESSING OF LEAD SCRAP 

SPENT BATTERY SCRAP 

The processing of spent batteries is carried out in a 

series of steps that includes draining the battery acid, dismantling the battery by hammer mill and grinding procedures, washing and tumbling the dismantled battery to separate its component parts (generally by screening and gravity separation steps), and, finally, treating the individual 

component parts for recovery and reuse. In the processing of 

the lead-acid battery, most of its components are recovered 

for reuse. The lead-containing components recovered from 

the battery consist of lead alloy from the grids and posts, 

lead oxides from the electrode paste, and other lead compounds from the battery cell reactions. Typically, the leadbearing paste is first desulfurized and combined with the 

lead-bearing grids and posts as a feed to a reverberatory furnace; this yields a raw lead product and a slag that contains 

20 percent to 40 percent lead. The slag is fed to a blast furnace or electric reduction furnace from which the lead content is recovered as raw lead product. The raw lead products 

from these furnaces are then melted in refining kettles to 

remove residual impurities, adjusted to customer specifications, and cast into ingots for shipment. In some facilities, 

the grids and posts are treated separately from the paste. In 

such operations, a rotary furnace that produces desired 

alloys for new battery production directly from the used 

grids and posts is used. 

The manner in which the sulfuric acid recovered from 

the batteries is treated to produce usable products, such as fertilizers, laundry detergent and paper-processing ingredients, 

regenerated electrolyte for use in new batteries, and a pH control solution for use in the wastewater-treatment system at the 

recycling facility, depends upon the particular recycling facility. The shredded polypropylene plastic battery casings are 

converted to plastic pellets onsite or shipped to a plastics 

recycler for eventual reuse in the production of new battery 

casings. Nonplastic components of the battery, such as rubber 

casing material and grid separators, may be used as reducing 

agents in the melting process for recovery of lead. 

Loss of lead is minimal in the processing of spent batteries. Environmental regulations in place for secondary 

lead smelters require that the loss of lead in these operations 

be significantly restricted. In June 1997, the EPA issued a 

direct final rule that amended certain components of the 

existing national emission standards for hazardous air pollutants from secondary lead smelting. This direct final rule, 

F7 

as amended, established standards to limit hazardous air 

pollutant emissions from agglomerating furnaces, dryers, 

fugitive dust sources, refining kettles, and smelting furnaces 

at lead smelters (U.S. Environmental Protection Agency, 

1997). 

BATTERY FABRICATION 

Battery manufacturers recover essentially all the scrap, 

which is mostly grid and post trimmings, generated in the 

battery assembly process. This home scrap is collected and 

remelted for use in the fabrication of more grids and posts. 

Minimal scrap or waste is generated in the production of the 

electrode paste. The small quantity that is recovered is 

reused as home scrap. 

OUTLOOK FOR LEAD RECYCLING 

The recycling efficiency level of 95 percent achieved 

in 1998 is likely to continue into the foreseeable future. 

Because the recycling efficiency is, however, already quite 

high, any further increase will be slight. Likewise, the recycling rate of 63 percent also is expected to remain at a high 

level. Only a decline in the demand for lead, thus lessening 

the need for primary material, is likely to raise it significantly. Such factors as environmental controls on lead, rising lead demand in the replacement battery sector, and the 

integral and appreciable role that the secondary lead industry plays in meeting overall U.S. demand for lead will continue to support significant recycling of lead. Continued 

high levels of lead recycling enhance the sustainability of 

lead production and result in greater conservation of energy 

and resources. 

On an international level, interest in lead recycling has 

been continuous and extensive. Increasing environmental 

concerns have prompted the institution of additional regulations on new lead production that have resulted in additional pressure and incentive to increase the recycling of lead in 

many countries around the world. Recycled lead now 

accounts for about one-half of the refined lead produced 

worldwide each year (International Lead and Zinc Study 

Group, 1995). 

Forecasts for lead recycling indicate that an additional 

1 Mt of secondary lead capacity will be required worldwide 

by 2008. The feed source for this capacity increase essentially will be that of the spent lead-acid batteries obtained 

from the ever-expanding number of vehicles throughout the 

world. In those regions where the number of vehicles is 

increasing to the greatest extent, however, challenges are 

expected to remain in achieving significant increases in 

recycling efficiency. Specifically, the collection of the 

spent automotive-type batteries and their transportation to 

appropriate recycling facilities will require the resolution 

of certain restrictions to battery recycling as outlined in the 

Basel Convention (International Lead and Zinc Study 

Group, 1998). 
F8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

REFERENCES CITED


American Metal Market, 1999, U.S. prices of smelters’ scrap lead: 

American Metal Market, v. 107, no. 160, August 19, p. 3. 

Battery Council International, 1998, National recycling rate study: 

Chicago, IL, Battery Council International (Prepared by 

Smith, Bucklin and Associates), December, 19 p. 

Briskey, J.A., and Wedow, H., Jr., 1986, Zinc resources, in Bever, 

M.B., ed., Encyclopedia of materials science and engineering: 

Oxford, Pergamon Press, p. 5539–5541. 

International Lead and Zinc Study Group, 1995, Recycling lead 

and zinc into the 21st century, in International Recycling 

Conference, 6th, Madrid, June 18–23, 1995, Proceedings: 

International Lead and Zinc Study Group, p. 15–16. 

——1998, Environmentally friendly lead and zinc—The challenge 

of the recycling millennium, in International Recycling Conference, 7th, Toronto, May 25–29, 1998, Proceedings: International Lead and Zinc Study Group, p. 9–12. 

——1999, Lead and zinc statistics: International Lead and Zinc 

Study Group, v. 39, no. 12, December, 67 p. 

Kirchhoff, C., 1894 [1895], Lead, in Mineral resources of the United States 1893: Miscellaneous Documents of the House of 

Representatives for the Second Session of the Fifty-Third 

Congress, 1893–94, v. 28, no. 181, p. 89–102. 

Long, K.R., DeYoung, J.H., Jr., and Ludington, Steve, 2000, Significant deposits of gold, silver, copper, lead, and zinc in the 

United States: Economic Geology, v. 95, no. 3, p. 629–644. 

Platt’s Metals Week, 1999, Annual metal averages for 1998: 

Platt’s Metals Week, v. 70, no. 8, February 22, p. 4. 

Rathjen, J.A., 1981, Lead, in Metals and minerals: U.S. Bureau of 

Mines Minerals Yearbook, 1980, v. I, p. 479–505. 

Shea, E.E., 1996, Lead regulation handbook: Rockville, MD, Government Institutes Inc., 240 p. 

Siebenthal, C.E., 1911, Lead, in Metals: U.S. Geological Survey 

Mineral resources of the United States 1909, pt. I, p. 181–201. 

Smith, G.R., 2000, Lead, in Metals and minerals: U.S. Geological 

Survey Minerals Yearbook 1998, v. I, p. 44.1–44.24. 

Smith, L.A., 1930, Lead, in Metals: U.S. Bureau of Mines Mineral 

Resources of the United States 1927, pt. I, p. 341–372. 

U.S. Environmental Protection Agency, 1996, Prohibition on gasoline containing lead or lead additives for highway use: Federal Register, v. 61, no. 23, February 2, p. 3832. 

——1997, National emission standards for hazardous air pollutants from secondary lead smelting—Direct final rule— 

Amendments to rule: Federal Register, v. 62, no. 114, June, 

13, p. 32209. 

Worden, Edward, 1998, Lead battery market varies: American 

Metal Market, v. 106, no. 241, December 17, p. 7, 
LEAD RECYCLING IN THE UNITED STATES IN 1998 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

F9 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

price. Total value of old lead scrap consumed calculated on 

the basis of an estimated value for the lead contained in 

whole battery scrap plus 75 percent of the unit value of 

primary lead for all other forms of lead scrap. The total 

value of old lead scrap exports was based upon the 

value for the gross weight of lead scrap as reported by 

the U.S. Census Bureau. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 
U.S. Department of the Interior

U.S. Geological Survey

Iron and Steel Recycling in the United States in 1998 

By Michael D. Fenton 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–G

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Sources of Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Sources of Iron and Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Home Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Old Scrap generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Disposition of Iron and Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Recycling Efficiency for Old Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Infrastructure of the Iron and Steel Scrap Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Processing of Iron and Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Summary and Outlook for Ferrous Scrap Recycling Flow . . . . . . . . . . . . . . . . . . . . . . . 5

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FIGURES 

1. 	Diagram showing U.S. steel materials flow in 1998 . . . . . . . . . . . . . . . . . . . . . . . G2 

2. 	Graph showing U.S. steel product shipments, by end-use sector, from 1979

through 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


TABLE 

1. 	Salient statistics for U.S. iron and steel scrap in 1998 . . . . . . . . . . . . . . . . . . . . . .G3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

Length 

kilometer (km) 0.6214 mile 

Mass 

kilogram (kg) 2.205 pound avoirdupois 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

For temperature conversions from degrees Celsius (°C) to degrees Fahrenheit (°F), use the following: 

°F = (1.8 × °C) + 32 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Iron and Steel Recycling in the United States in 1998 

By Michael D. Fenton 

ABSTRACT 

Consumption of iron and steel scrap and the health of 

the scrap industry depend directly on the health of the steelmaking industry. The United States, as well as most of the 

world, is expected to consume increasing amounts of scrap 

as a steadily increasing population demands more steel 

products. World resources of scrap should be sufficient for 

the foreseeable future. An estimated 75 million metric tons 

of scrap was generated during 1998 in the United States, 

and 35 million tons of old scrap and 18 million tons of new 

scrap were consumed. The recycling efficiency was calculated to be 52 percent, and the recycling rate was found to 

be 41 percent. 

INTRODUCTION 

Iron, which includes its refined product steel, is the 

most widely used of all the metals. Iron and steel products 

are used in many construction and industrial applications, 

such as appliances, bridges, buildings, containers, highways, machinery, tools, and vehicles. The recycling1 of iron 

and steel scrap (ferrous scrap) is an important activity 

worldwide, especially in the United States where 73 million 

metric tons (Mt) of new, old, and home scrap was consumed 

in the making of new steel during 1998. Obsolete iron and 

steel products and the ferrous scrap generated in steel mills 

and steel-product manufacturing plants are collected 

because recycling iron and steel products by melting and 

recasting them into semifinished forms for use in the manufacture of new steel products is economically advantageous. 

The steel scrap market is mature and highly efficient. The 

recycling rate for steel scrap, which was defined by the Steel 

Recycling Institute as total scrap recovered versus total raw 

steel produced, has exceeded 50 percent every year since 

World War II and has been more than 60 percent for about 

two decades. 

Iron and steel scrap is more than just economically beneficial to steelmakers; ferrous scrap recycling is part of wise 

management of iron resources. Recovery of 1 metric ton (t) 

of steel from scrap conserves an estimated 1,030 kilograms 

(kg) of iron ore, 580 kg of coal, and 50 kg of limestone. 

1Definitions for selected words are found in the Appendix. 

Each year, steel recycling saves the energy equivalent 

required to electrically power about one-fifth of the households in the United States (about 18 million homes) for 1 

year (Steel Recycling Institute, 1999). In the production of 

steel, 99.9 percent of scrap melted is consumed in the new 

steel while producing negligible environmentally undesirable waste. 

This materials flow study, as summarized in figure 1, 

describes the materials cycle of pig iron, direct reduced iron 

(DRI), and scrap used in the manufacture of iron and steel 

products; the recycling of scrap; and the losses of iron and 

steel during the steelmaking and product fabrication 

processes during 1998. The flow diagram shows the quantities of iron present at stages of steel product manufacture, 

shipping, and recycling. 

In a free-market economy, scrap prices react quickly to 

changes in supply and, especially, demand. When demand 

for steel mill and foundry products is low, demand for scrap 

is low, and prices fall. Dealers cannot influence sales of 

scrap if mills and foundries do not need it to charge their 

furnaces. Although prices of scrap depend upon the market 

conditions for new products, the scrap industry uses inventory to absorb price differentials; that is, inventories 

increase as scrap prices decrease. Prices are also influenced 

by technological changes in mills, processing of scrap, the 

use of scrap substitutes, environmental controls and other 

Government regulations, and export demand. During the 

decade prior to 1998, the average annual composite price of 

No. 1 Heavy Melting Steel scrap, which was an industry 

standard, fluctuated between $84.67 and $135.03 per metric 

ton. Ferrous scrap prices declined significantly during 1991 

and 1992 as domestic and world demand for scrap 

decreased. The period from 1993 to 1995 was one of 

strengthening demand and rising prices to a peak average 

price of $130.60 per ton in 1995. Prices then declined to an 

average of $108.30 in 1998. 

In 1998, an estimated old scrap supply of more than 78 

Mt was available for recycling, and about 35 Mt valued at 

nearly $3.8 billion was recycled in the United States. About 

18 Mt of new scrap was consumed, and about 38 Mt was 

unrecovered. The old scrap recycling efficiency was 52 percent, and the recycling rate was 41 percent (table 1). 

G1 
G2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 1. U.S. steel materials flow in 1998. Values are in million metric tons. DRI is direct-reduced iron. 
IRON AND STEEL RECYCLING IN THE UNITED STATES IN 1998 G3 

Table 1. Salient statistics for U.S. iron and steel scrap in 1998. 

[Thousand metric tons, unless otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 75,000 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 35,000 

Consumption value3 . . . . . . . . . . . . . . . . $3.79 billion 

Recycling efficiency4 . . . . . . . . . . . . . . . . . 52 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78,000 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . 38,000 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . 18,000 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . 34:66 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . 41 percent 

U.S. net exports of scrap10 . . . . . . . . . . . . . . . . . . . . 2,510 

Value of U.S. net exports of scrap3 . . . . . . . . $272 million 

1Old scrap that will theoretically become obsolete in the United States 

in 1998. Dissipative uses are excluded. 

2Old sscrap recycled in 1998. 

3Based on average 1998 three-city composite price (Chicago, Philadelphia, Pittsburgh) of $108.30 per metric ton, published by American Metal Market, used to calculate values of old scrap consumed and U.S. net scrap exports. 

4(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus the old scrap imports plus old scrap stock decrease). 

5Old scrap generated plus old scrap imported plus old scrap stock 

decrease. 

6Old scrap supply minus old scrap consume plus old scrap stock 

decrease minus old scrap exports. 

7Includes prompt industrial scrap but excludes home scrap. 

8Ratio of quantities consumed, each measured in weight and 

expressed as a percentage of old plus new scrap consumed. 

9Fraction of supply that is scrap on an annual basis. Old plus new 

scrap consumed divided by apparent supply (primary plus secondary production (old plus new scrap) plus imports minus exports plus adjustment for 

industry stock changes), in percent. 

10Trade in scrap is assumed to be principally in old scrap. 

SOURCES OF IRON 

Approximately three-quarters of the iron ore used by 

domestic integrated steel mills to make iron and steel originated in the United States in 1998. Brazil, Canada, and 

Venezuela accounted for more than 90 percent of iron ore 

imports, which average about 15 million metric tons per 

year. Domestic consumption of iron ore was about 78 Mt in 

1998. Almost all the ore is produced in Michigan and Minnesota from taconite, which is a low-grade ore; almost all the 

ore is produced in the form of pellets. In 1998, the quantity 

of iron ore by type consumed at U.S. iron and steel plants 

was pellets, 63 Mt, sinter, 11 Mt, and direct shipping ore, 

900,000 t. Integrated steel mills consumed about 16 Mt of 

iron and steel scrap and 400,000 t of DRI in blast and basic 

oxygen furnaces during 1998. Minimills that use electric arc 

furnaces consumed about 3.4 Mt of pig iron and about 42 Mt 

of scrap during 1998. Thus, steel scrap comprised about 43 

percent of iron units supplied for steelmaking. During 1998, 

minimills also consumed about 1 Mt of DRI to improve steel 

quality; this was moderately higher than in previous years. 

About 87 percent of DRI imports, or 900,000 t, came from 

Venezuela. 

SOURCES OF IRON AND STEEL SCRAP 

Sources of different types of scrap are key features of 

the flow diagram (figure 1). Ferrous scrap available for 

recycling comprises home, old, and new scrap. Home (mill 

or revert) scrap is generated within the steel mill during production of iron and steel. Trimmings of mill products and 

defective products are collected and quickly recycled back 

into the steel furnace because their chemical compositions 

are known. The availability of home scrap has been declining as new and more-efficient methods of casting have been 

adopted by the industry. Old scrap includes metal articles 

that have been discarded after serving a useful purpose. 

Because of the wide variety of chemical and physical characteristics, old scrap often requires significant preparation, 

such as sorting, de-tinning, and de-zincing, prior to consumption in mills. New (prompt or industrial) scrap is produced from trimmings and discards during product manufacture. Statistical data for domestic consumption of home 

and old scrap were collected by the U.S. Geological Survey 

(USGS) (figure 1). Industry analysts estimate the amount of 

new scrap to be 15 percent of apparent consumption of steel 

mill products. 

The domestic supplies of primary and secondary iron as 

shown in figure 1 consist of inputs from domestic steel mills 

and DRI producers, imports, and the supply of old scrap 

available for recycling. Statistical data were collected by the 

USGS, the American Iron and Steel Institute, and the U.S. 

Census Bureau. 

HOME SCRAP 

Home scrap consists of scrap that is produced in steel 

mills and foundries as a byproduct of their operations, as 

well as old plant scrap. This scrap has a known composition 

and is always recycled to the furnace for remelting. Home 

scrap generated and recycled in 1998 totaled about 20 Mt. 

OLD SCRAP GENERATED 

Old scrap is available for recycling. The largest source 

is junked automobiles followed by appliances, machinery, 

worn out railroad cars and tracks, demolished steel structures, and other products. Old scrap estimated as being 

available for recycling consisted of products in circulation 

that became obsolete in the United States in 1998. On the 

basis of the estimated average useful life of products and on 

the amounts of iron and steel contained in the various market classes in the appropriate prior years, the estimates of 

obsolescence developed by market class total 75 Mt. The 

weighted average product life was 19 years. 
G4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

NEW SCRAP 

New scrap is generated from manufacturing plants that 

make steel products. Scrap accumulates when steel is cut, 

drawn, extruded, or machined. The casting process also produces scrap as excess metal. Its chemical and physical characteristics are known, and it is usually transported quickly 

back to steel plants through scrap processors and dealers or 

directly back to the steel plant for remelting to avoid storage 

space and inventory control costs. The supply of new scrap 

is a function of industrial activity. When activity is high, 

more industrial scrap is generated. New scrap generated and 

recycled in 1998 was estimated to be 18 Mt. The new scrapto-old-scrap ratio during 1998 was 34:66. 

DISPOSITION OF IRON AND STEEL 

SCRAP 

The U.S. steel industry reports scrap receipts and consumption to the USGS. Also, the U.S. Census Bureau 

reports scrap imports and exports. Apparent steel supply or 

consumption is the amount of steel products available within the United States. A unit of imported semifinished steel is 

included in finished steel shipments of companies that 

report to the American Iron and Steel Institute. These shipments and imports are added together to calculate apparent 

supply. Thus, this unit must be removed from imports to 

avoid double counting and overestimating of apparent consumption. In the model presented here, the starting point for 

ferrous scrap flow, through processing, is old scrap generated, which is the estimated 75 Mt of iron and steel that 

became obsolete in 1998. The old scrap supply available for 

recycling in the domestic steelmaking industry is 78 Mt, 

which is the amount of old scrap generated with 3 Mt old 

scrap imports added. 

Some scrap is lost to the environment and is unrecoverable. Scrap that is discarded to scrap yards or abandoned 

in place is considered to be temporarily unrecoverable and 

may be recycled at some future date. In 1998, the steel 

industry used 35 Mt of old scrap and exported 6 Mt. Unrecovered old scrap, which is old scrap supply minus old 

scrap consumed minus old scrap exports, was estimated to 

be 37 Mt for 1998. 

RECYCLING EFFICIENCY FOR OLD 

SCRAP 

The relation between the amount of scrap that is theoretically available for recycling and what is recovered and 

reused is called recycling efficiency in this report. Old scrap 

recycling efficiency during 1998 was 52 percent. Recycling 

efficiency is not expected to increase significantly because 

ferrous scrap competes with direct reduced iron and pig iron 

as a raw material, both of which are readily available and 

tend to hold down scrap prices, thereby limiting scrap availability and recycling efficiency. 

INFRASTRUCTURE OF THE IRON AND 

STEEL SCRAP INDUSTRY 

Steel mills and foundries require ferrous scrap provided 

by brokers and scrap collectors and processors. Brokers 

bring scrap buyers and sellers together on a scrap transaction and receive a fee for this service. Consumers use brokers to procure scrap; processors use their services to market their scrap. Brokers purchase scrap without having storage or processing facilities for a particular client buyer or 

with the hope of finding a future buyer offering a favorable 

price and profit. More than 16,000 automotive dismantlers 

and thousands of scrap processing facilities in the United 

States play an integral role in the steel industry by collecting 

and preparing scrap for transport to steel mills that need raw 

materials (Steel Recycling Institute, 2000). The greatest 

concentration of these facilities is in the northeastern, northcentral, and middle Atlantic regions because the large population uses more steel products and generates more scrap. 

The scrap recycling infrastructure causes the recycling rate 

of steel in the United States to be equal to and, in most cases, 

to exceed that of other industrialized countries. The rate is 

much higher than that of lesser developed countries. 

PROCESSING OF IRON AND STEEL 

SCRAP 

By using a variety of equipment, scrap dealers collect and 

process scrap into a physical form and chemical composition 

that steel mill furnaces can consume. The type and size of 

equipment they use depends on the types and volume of scrap 

available in the area and the requirements of their customers. 

The largest and most expensive piece of equipment is the 

shredder. The shredder can fragment vehicles and other discarded steel objects into fist-sized pieces of glass, various 

metals, plastic, and rubber. These materials are segregated 

before shipment by using air ducts, fans, flotation equipment, 

hand pickers, and magnets. Hydraulic shears, which have cutting knives of chromium-nickel-molybdenum alloy steel for 

hardness, slice heavy pieces of railroad car sides, ship plate, 

and structural steel into chargeable pieces. Baling presses are 

used to compact scrap into manageable bundles, thereby 

reducing scrap volume and shipping costs. Scrap dealers must 

carefully sort the scrap they sell, and steelmakers must be 

careful to purchase scrap that does not contain unacceptable 

levels of undesirable elements. Total scrap processing capability in the United States has been estimated to be 118 Mt 

(Robert Garino, Director of Commodities, Institute of Scrap 

Recycling Industries, Inc., written commun., January 2, 2001). 

Old and new scrap consumed or recycled during 1998 was 

about 53 Mt. Recycled automobiles accounted for about onesixth of the ferrous scrap recycled by the U.S. steel industry in 

1998. About 16,000 automobile dismantlers and 202 shredders 

in the United States disassembled and shredded automobiles in 

1998 (Recycling Today, 1998); appliances, bicycles, and other 
IRON AND STEEL RECYCLING IN THE UNITED STATES IN 1998 G5 

Figure 2. U.S. steel product shipments by end-use sector, from 1979 through 1998. 

steel products are also shredded for recycling. More than 1,500 

scrap yards process steel from construction and demolition 

sites by shearing, shredding, and baling. By comparing the 

annual tonnage of steel used to produce the new product with 

the tonnage of recycled product, steel recycling rates during 

1998 were determined for the following: automobiles, 92 percent; construction plate and beams, 88 percent; appliances, 72 

percent; steel cans, 56 percent; and other products, 64 percent 

(Institute of Scrap Recycling Industries, 1999). 

Steel mills melt scrap in basic oxygen furnaces (BOF), 

electric arc furnaces (EAF), and, to a minor extent, blast furnaces. The proportion of scrap in the charge in a BOF is limited to less than 30 percent, whereas that in an EAF can be 

as much as 100 percent. Steel and iron foundries use scrap 

in EAFs and cupola furnaces. In 1998, BOFs were used to 

produce 55 percent of the total steel in the United States 

while using only 19 percent of total scrap consumed (American Iron and Steel Institute, 1998, p. 75). During the same 

period, EAFs produced 45 percent of total steel while using 

62 percent of total scrap consumed. Scrap was also melted 

in blast furnaces and other types of furnaces. 

Fabrication of new steel products produces new steel 

scrap that is relatively clean, chemically and physically, and of 

known chemical composition. For this reason, most scrap consumers prefer new scrap to old scrap. Preparation of new scrap 

is usually limited to cutting, cleaning, and baling prior to rapid 

transport back to the steelmaker for recycling. 

SUMMARY AND OUTLOOK FOR 

FERROUS SCRAP RECYCLING FLOW 

Consumption of ferrous scrap and the growth or 

decline of the scrap industry depends directly on the 

health of the steelmaking industry. Most regions of the 

world will see a marked increase in steel consumption 

during the next 5 years, according to the International 

Iron and Steel Institute (American Metal Market, 2000). 

In the United States, a steadily increasing population and 

a growing economy in the long term should assure that 

demand for steel products and the scrap used to make 

them will also increase. Steel and scrap consumption will 

continue to be in strong demand in the automotive and 

consumer appliance sectors. New highway and bridge 

projects supported by increased Federal funding will 

require structural and reinforcement bar products. The use 

of steel framing is increasing in the construction of multifamily developments, retirement homes, and single-family residences. Steel demand for can production, which 

includes aerosols, food, and paint, should remain strong 

in the long term. A thriving steel industry is dependent on 

plentiful inexpensive energy. As energy costs increase, the 

demand for steel pipe and tubular goods used in the oil 

and gas industry will increase for new drilling projects. 

Foundries are an important market for tin-bearing scrap 

from recycled cans. 
G6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Relative consumption of iron and steel scrap in four major 

markets (construction, containers, transportation, and distributors) from 1979 through 1998 may be inferred from shipments 

of steel mill products by the end-use sector as shown in figure 

2. Total shipments and inferred scrap consumption in all sectors shown in the figure declined during the early 1980s, but by 

1998, they regained the levels of the late 1970s. During the 20­

year period, the proportion of steel containers to the total 

decreased from 7 to 4 percent, that of transportation decreased 

to 16 percent from 24 percent, and that of construction materials increased only slightly to 15 percent from 13 percent. 

The EAF contribution to the total production of steel has 

risen dramatically, and the proportion of EAF steel produced 

should continue to increase, perhaps at a rate of 4 percent per 

year during the next 10 years (Steel Times International, 

2000). The EAF may be the primary steel production method 

in the world by 2010 (Forster, 1999). The EAF has evolved in 

minimills from the small unit limited in use for specialty steel 

production to the large-capacity unit used to produce a wide 

range of steels, which includes the long product bars, structural shapes, tubulars, wire, rails, and flat product sheet and plate. 

The availability of scrap and operating and capital cost 

advantages have made EAF growth possible. Locations of 

new minimills in areas of increasing population growth and 

manufacturing activity in the Southern States and the Western States and away from the traditional “rust belt” States 

have, to a large extent, satisfied demand for construction steel 

products and products used by the oil and gas industry. The 

EAF process is flexible in its raw material requirements and 

sources and can operate with considerable flexibility in making products depending on market requirements.Steelmaking 

by the EAF will continue to grow because of the capital and 

operating cost advantages relative to those of the BOF, the 

increasingly wide range of steel products that it makes, and 

its environmental cleanliness. The use of the EAF is the most 

effective way of reducing carbon dioxide emissions because 

of the lower energy needed to melt scrap than to smelt ore. 

Use of EAFs will increase as new minimills are built, and 

EAFs may replace operating BOFs. Ispat Inland, Inc., has 

been considering the replacement of one of its two BOFs 

with an EAF, which would create new demand for large 

amounts of ferrous scrap, as much as 900,000 metric tons per 

year (Worden, 2000). As the expansion of the EAF in the 

United States continues, ferrous scrap will continue to be 

available in sufficient quantities worldwide, but the role of 

the United States as the world's largest scrap supplier may 

diminish in importance (Katrak and others, 1999). 

Ferrous scrap will remain the most important raw material used, but reduced iron in the form of DRI and hot- briquetted iron (HBI) will become a larger component in the raw 

materials mix for EAF steel production. Increasing availability 

from domestic producers of DRI and HBI will be a factor in 

this trend as will the increasing need for low-residual feedstock 

for the production of high-quality flat steel and special-barquality steels required to compete in the higher end markets. 

E-commerce has been making progress at different rates 

in the steel industry as well as in many sectors of the economy. Selling scrap through e-commerce has potential, but 

adoption of e-commerce marketing by the ferrous scrap 

industry will probably be a slow evolutionary process. For ecommerce to be adopted, scrap processors, dealers, and brokers must realize the value of this new Internet technology 

and see potential gains in profits and efficiency. 

A major problem for world and U.S. steel industries is 

that the world is producing too much steel. Except for North 

America, world steelmaking capacity is excessive relative to 

demand–perhaps as much as 15 percent more than can be 

consumed (Matthews, 2000). Companies continue to expand 

production by about 2 percent per year as profits decline. 

Excess steel production from major steelmaking nations is 

being imported into the United States because of its strong 

economy and open market system. The result has been 

declining domestic steel production, falling steel prices, and 

declining scrap demand and prices. Support seems to be 

increasing for consolidation among domestic steelmakers 

followed by the closing of inefficient plants and production 

reductions. Also, increased communications between scrap 

processors and consumers to resolve common issues of concern, such as quality control, the universality of specifications, and delivery services, will help maintain profitability 

for all concerned. 

Recycling a large amount of scrap steel reduces the 

total energy needed to produce steel. Nevertheless, the steel 

industry uses about 3 percent of the energy consumed in the 

United States and more than 10 percent of that used by the 

industrial sector. Energy purchases represent nearly 20 percent of the total manufacturing cost of steel. Of particular 

concern is the recent trend toward declining availability of 

and higher prices for oil, gas, and electricity. To control 

these significant production costs, the industry will use and 

promote, as much as possible, new technologies to conserve 

energy, such as scrap preheating. Scrap preheating may 

increase threefold in new furnaces owing to energy conservation, shorter cycle times, and reduced operating costs 

(Steel Times, 2001). Another technology advance is the 

development of strip casting that reduces energy usage by as 

much as 50 percent by casting steel into its final thickness 

and shape with minimal further hot or cold rolling. Of 

immense concern to the scrap and steelmaking industries is 

the threat of accidental melting of radioactive scrap. Steel 

mills that receive ferrous scrap have been exposed to 

radioactive materials without warning. Such accidents can 

be extraordinarily expensive to steelmakers. In 2001, the 

Federal Government proposed releasing very low-level 

radioactive scrap into the recycling stream, an action that is 

vigorously opposed by the scrap and steelmaking industries. 

The Metals Industry Recycling Coalition has been trying to 

persuade the U.S. Department of Energy, the Nuclear Regulatory Agency, and the U.S. Congress to keep any radioactively contaminated scrap out of the commerce stream. 
IRON AND STEEL RECYCLING IN THE UNITED STATES IN 1998 

REFERENCES CITED


American Iron and Steel Institute, 1998, Annual report 1998: Washington, D.C., American Iron and Steel Institute, 122 p. 

American Metal Market, 2000, IISI sees consumption up 2% to 

830 M tons by 2005: American Metal Market, v. 108, no. 

193, October 5, p. 1. 

Forster, Harriet, 1999, Global growth seen for EAF into millennium: American Metal Market Electric Furnace Supplement, 

February 4, p. 17A. 

Institute of Scrap Recycling Industries, accessed October 15, 1999, 

at URL http://www.isri.org/viewpage.cfm?pgname=2.0. 

Katrak, F.E., Agarwal, J.C., and Persampieri, David, 1999, Global 

restructuring of the steel industry: American Metal Market 

Steel Forecast Supplement, January 5, p. 15A. 

Marley, Michael, 2000, Role as ‘largest scrapyard’ changing, 

Special Report, accessed March 17, 2000, at URL 

http://www.amm.com/subscrib/2000/mar/special/0314 1.htm. 

G7 

Matthews, R.G., 2000, Too much steel, too few remedies (The 

Outlook): Wall Street Journal, October 23, p. A1. 

Recycling Today, 1998, Potential scrap shortage no hindrance to 

steel industry: Recycling Today, v. 36, no. 1, January, p. 14. 

Steel Recycling Institute, [1999], A few facts about steel—North 

America's #1 recycled material, Fact Sheet, accessed July 13, 

1999, at URL http://www.recycle steel.org/fact/. 

Steel Recycling Institute, [2000], The inherent recycled content 

of today's steel, accessed August 21, 2000, at URL 

http://recycle-steel.org/buy/BuyInherent.html. 

Steel Times, 2001, IISI study on the evolution of EAF to 2010: 

Steel Times, v. 228, no. 1, January, p. 14. 

Steel Times International, 2000, Technical challenges of EAF 

steelmaking in 2010: Steel Times International, March, p. 18. 

Worden, Edward, 2000, Ispat scrap needs could rise with furnace 

conversion plan: American Metal Market, v. 108, no. 178, 

September 14, p. 11. 
G8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle. 

downgraded scrap. Scrap intended for use in making a 

metal product of lower value than the metal product 

from which the scrap was derived. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

primary metal commodity. Metal commodity produced or 

coproduced from metallic ore. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

secondary metal commodity. Metal commodity derived 

from or contained in scrap. 
U.S. Department of the Interior

U.S. Geological Survey

Manganese Recycling in the United States in 1998


By Thomas S. Jones 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–H

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Old Scrap generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Disposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Recycling Efficiency for Old Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Processing of Manganese-Bearing Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Iron and Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Used Aluminum Beverage Cans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Summary and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

FIGURES 

1. 	Flow Diagram showing U.S. manganese materials flow in 1998 . . . . . . . . . . . . . . H2

2. 	Graph showing U.S. manganese consumption, by end-use pattern, from 1979

through 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

TABLE 

1. Salient statistics for U.S. manganese-bearing scrap in 1998 . . . . . . . . . . . . . . . . . .H3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

kilometer (km) 

inch (in.) 

Length 

0.6214 

25.4 

mile 

millimeter 

Volume 

cubic foot (ft3

) 0.02832 cubic meter 

Mass 

gram (g) 

kilogram (kg) 

kilogram (kg) 

metric ton (t, 1,000 kg) 

troy ounce (troy oz) 

0.03527 

2.205 

32.1507 

1.102 

31.10 

ounce avoirdupois 

pound avoirdupois 

troy ounce 

short ton (2,000 pounds) 

gram 

For temperature conversions from degrees Celsius (°C) to degrees Fahrenheit (°F), use the following: 

°F = (1.8 × °C) + 32 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Manganese Recycling in the United States in 1998 

By Thomas S. Jones 

ABSTRACT 

This report describes the flow and processing of manganese within the U.S. economy in 1998 with emphasis on 

the extent to which manganese is recycled. Manganese was 

used mostly as an alloying agent in alloys in which it was a 

minor component. Manganese was recycled mostly within 

scrap of iron and steel. A small amount was recycled within used aluminum beverage cans. Very little manganese was 

recycled from materials being recovered specifically for 

their manganese content. For the United States in 1998, 

218,000 metric tons of manganese was estimated to have 

been recycled from old scrap, of which 96 percent was from 

iron and steel scrap. Efficiency of recycling was estimated 

to be 53 percent, and the recycling rate, 37 percent. Metallurgical loss of manganese was estimated to be about 1.7 

times that recycled. This loss was mostly into slags from 

iron and steel production from which recovery of manganese has yet to be shown economically feasible. 

INTRODUCTION 

The purpose of this study is to document the extent to 

which manganese is being recycled in the United States, to 

identify trends in domestic manganese recycling1, and to 

determine the implications of these trends for sustainability 

of manganese use. The base year for the study is 1998. 

Manganese (atomic number 25) is in Group 7 of the 

Periodic Table. In that table, its closest neighbors are, to the 

left, vanadium and chromium and, to the right, iron, cobalt, 

and nickel. Thus, it is not surprising that manganese should 

be considered a ferrous metal and that its major use is in 

iron-base alloys (steel and cast iron). Because manganese 

metal typically is brittle and unworkable, only a small 

amount can be used as an alloy in which manganese is the 

major component. Rather, manganese is used predominantly 

in alloys where it is a minor component, principally in steel 

and, to a lesser extent, aluminum. Manganese is essential to 

steel production by virtue of its sulfur-fixing, deoxidizing, 

and alloying properties. 

In nonmetallurgical uses, the most common valences 

for manganese are two and four, and oxygen is the main 

element with which manganese is combined. Accordingly, 

1Definitions for select words are found in the Appendix. 

the mineral and commodity chemistry of manganese centers on such compounds as manganous oxide (MnO), manganese dioxide (MnO2

), manganese carbonate (MnCO3), 

and manganese sulfate (MnSO4). Pyrolusite (a mineral 

form of manganese dioxide), braunite (an oxysilicate), and 

rhodochrosite (a manganese carbonate) are among the minerals more commonly found in manganese ores. In 1998, 

the leading producers of ore were Australia, Brazil, China, 

Gabon (the leading U.S. source), India, South Africa, and 

Ukraine. 

When a reductant (carbon) is present in the charge to a 

process for making iron or steel, some manganese ore is 

used directly. Examples include addition to the charge to an 

iron blast furnace and direct smelting of ore during steelmaking (Japan). For the most part, however, ore is smelted 

and reduced to its metallic content by carbon predominantly 

in submerged-arc electric furnaces but also in blast furnaces. 

Because manganese ores typically contain iron as well, the 

result of smelting is an iron-bearing ferroalloy, which is 

used subsequently to add manganese to liquid metal during 

steelmaking. The principal manganese ferroalloys and 

their typical components are high-carbon ferromanganese 

(78 percent manganese, 7 percent carbon, balance mostly 

iron) and silicomanganese (66 percent manganese, 17 percent silicon, 2 percent carbon). An electrolytic process is 

used to obtain electrolytic manganese dioxide (EMD) and 

most manganese metal, the two other forms in which manganese is commercially most used. The sequence of steps 

usually used in producing these two materials is similar— 

leaching manganese feed with sulfuric acid and electrodepositing EMD or metal from the leach liquor after it has 

been purified. 

Metallurgical applications account for most domestic 

manganese consumption, of which 85 to 90 percent has been 

going to steelmaking and about 8 percent, to the manufacture 

of dry cell batteries. The preponderance of the manganese 

used domestically for making batteries is now EMD because 

usage of natural battery ore has declined greatly. The manufacture of manganese chemicals, such as potassium permanganate, and agricultural use of manganese in animal feed and 

plant fertilizer as oxide, sulfate, and oxysulfate together 

account for another 5 percent of use. These patterns of 

domestic use are typical for other industrialized countries 

having well-developed steel industries. 

H1 
H2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 1. U.S. manganese materials flow in 1998. Values are in thousand metric tons of manganese content. 
MANGANESE RECYCLING IN THE UNITED STATES IN 1998 H3 

Table 1. Salient statistics for U.S. manganese-bearing in 1998. 

[Values in thousand metric tons of contained manganese, unless 

otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 

Consumption value . . . . . . . . . . . . . . . . $120 million 

Recycling efficiency3 . . . . . . . . . . . . . . . . . 53 percent 

Supply4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481 

Unrecovered5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 

New scrap consumed6 . . . . . . . . . . . . . . . . . . . . . . . . . 108 

New-to-old-scrap ratio7 . . . . . . . . . . . . . . . . . . . . . . 33:67 

Recycling rate8 . . . . . . . . . . . . . . . . . . . . . . . . . 37 percent 

U.S. net exports of scrap9 . . . . . . . . . . . . . . . . . . . . . . . 18 

Value of U.S. net exports of scrap . . . . . . . . . . $10 million

1Old scrap that will theoretically become obsolete in the United States 

in 1998. Dissipative uses are excluded. 

2Old scrap recycled in 1998. 

3(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported). 

4Old scrap generated plus old scrap imported. 

5Old scrap supply minus old scrap consumed minus old scrap exported. 

6Includes prompt industrial scrap but excludes home scrap. 

7Ratio of quantities consumed, in percent. 

8Fraction of supply that is scrap on an annual basis. It is defined as 

(consumption of old scrap plus consumption of new scrap) divided by 

apparent supply (see appendix), measured in weight and expressed as a 

percentage. 

9Trade in scrap is assumed to be principally in old scrap. 

For 1998, the average price for U.S. delivery of metallurgical-grade ore was assessed at $2.40 per metric ton unit, 

on the basis of cost, insurance, and freight; and the yearaverage free-on-board price for imported high-carbon ferromanganese was $502 per long ton of alloy (Jones, 2000, p. 

49.2-49.3). At per kilogram of contained manganese, these 

prices equate to 24 cents for ore and 63 cents for high-carbon ferromanganese. For 1993 through 1998, the ore prices 

were reasonably steady following a decline from a peak of 

$3.78 per metric ton unit in 1990 (Jones, 1999). In the 1990s 

through 1998, the price trend for high-carbon ferromanganese had been gradually declining from a maximum of 

about $650 per long ton of alloy in 1990. 

The salient statistics for manganese-bearing scrap 

given in table 1 are based mainly on and determined by the 

status of recycling for iron and steel. The recycling of iron 

and steel scrap is the subject of another report by the U.S. 

Geological Survey (USGS) to which the reader is referred 

for details (Fenton, in press). Those aspects that deal with 

iron and steel scrap are given only in summary form in this 

report. Two of the three ratios given in table 1 are nearly the 

same as the ratio for manganese and iron and steel scrap— 

old scrap recycling efficiencies of 53 percent for manganese 

and 52 percent for iron and steel scrap and new-to-old-scrap 

ratios of 33 to 67 for manganese and 34 to 66 for iron and 

steel scrap. The lower recycling rate for manganese (37 percent) than that for iron and steel scrap (41 percent) reflects 

the relatively large loss of manganese during metallurgical 

processing. Figures given in table 1 for the value of the 

manganese units in scrap are based on a unit value of $560 

per metric ton of manganese as estimated from foreign trade 

data for 1998. 

The only significant metal form recovered specifically 

because of its manganese content was wear-resistant steel in 

which the manganese content typically is about 12 percent 

(so-called Hadfield steel). Otherwise, recovery of manganese in metal was incidental to the recycling of another 

metal—iron in the case of steel scrap and iron castings and 

aluminum in the case of used beverage cans (UBCs). 

A small amount of manganese was recovered through 

recycling of dry cell batteries or manganese-bearing wastes 

generated in battery manufacture. One battery company 

formed a partnership with a steel company whereby more 

than 1,000 metric tons per year of scrap from the battery 

company was to be consumed in steel production (Watson, 

Andersen, and Holt, 1998). With a manganese content of 20 

percent, this volume might be expected to contain about 200 

metric tons (t) of manganese (Ferlay and Weill, 2000). Battery recycling is not considered further in this report 

because the quantity of manganese being recycled from batteries was relatively small and not precisely known. 

SOURCES 

Figure 1 is a composite derived from knowledge of the 

flows of manganese and manganese-bearing materials, such 

as iron and steel scrap and aluminum UBCs. The data for 

the majority of the diagram are based on the material flow 

relations for iron and steel scrap, in which the manganese 

content is taken to be 0.6 percent throughout, as suggested 

by Jones (1994, p. 42), for average manganese content of 

steel. Scrap of high-manganese Hadfield steel is not treated 

as a separate item. Its annual domestic production was not 

known but is estimated to be about 50,000 t as inferred from 

shipments (Kirgin, 2000). Even if it were recycled at a 75­

percent rate, the manganese content of manganese steel 

scrap would only be about 2 percent of the estimated manganese content of the 35 million metric tons (Mt) of iron and 

steel scrap consumed/recycled in 1998. 

The inputs to the primary supply of manganese as diagrammed in the upper left of figure 1 consist of drawdowns 

of industry and Government stocks of manganese materials, 

imports of manganese materials (dioxide, ferroalloys, metal, 

ores), and imports of raw steel. Of this, 4 units (4,000 t) of 

manganese exported as ore and 102 units of manganese destined for battery and chemical uses bypass metallurgical 

processing and flow directly to the output (right) side of the 

diagram. The balance of the primary supply goes mainly 

into the manufacture of ferroalloys and steel. Most of the 
H4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

ferroalloys and metal were used in steelmaking, but 31 units 

were exported and are included within the 65 units of 

exports. 

The principal data sources for this report are Fenton 

(2000b, c), Jones (2000), and the sources upon which the 

data in those chapters were based. Quantities for manganese 

end uses are obtained from data collected by means of the 

Manganese Ore and Products Survey of the USGS. 

The types of manganese-bearing products ultimately 

becoming scrap and the industries in which they were used 

can be inferred by considering the pattern of manganese 

consumption. This is shown for 1979 through 1998 in figure 2, in which an estimated total of 730,000 t of manganese was used for 1997; this replaced the anomalously 

low total of 643,000 t published in the 1999-2001 USGS 

Minerals Yearbooks. Construction, machinery, and transportation have been the larger of the consuming sectors. 

The “All Other” category includes steel for nonspecified 

uses as well as a number of other minor steel categories 

(appliances and equipment, cans and containers, and oil 

and gas industries). 

OLD SCRAP GENERATED 

Old scrap generated was mostly iron and steel scrap. 

The first step in estimating this component was to assign 

lifetimes to various steel products as categorized in the 

steel shipments data published in the Annual Statistical 

Reports of the American Iron and Steel Institute. For iron 

and steel scrap, the weighted average product life was 19 

years. For each product, the quantity of steel becoming 

obsolete in 1998 was taken to be that shipped at the beginning of its life. For example, the quantity for a product with 

a lifetime of 20 years was the quantity of that product 

shipped in 1978. 

Scrap from aluminum UBCs made only a small contribution to old scrap generated. Estimation of the addition to 

manganese recycling from UBCs is discussed in detail in 

the “Processing of Manganese-Bearing Scrap” section of 

this report. 

NEW SCRAP 

New scrap consists entirely of iron and steel scrap that 

results from fabricating operations and is often returned 

directly from the fabricator to the originating steel plant. 

The quantity of new scrap generated is taken as being equal 

to 15 percent of apparent consumption of steel (Fenton, in 

press). Apparent consumption of steel in 1998 was 118 Mt 

(Fenton, 2000a). The quantity of new scrap consumed is 

assumed to be equal to that generated without losses or 

additions. As indicated in figure 1, the quantity of new scrap 

generated was about one-fourth of the quantity of old scrap 

generated. 

DISPOSITION 

The supply of old scrap consists of old scrap from iron 

and steel scrap plus a small amount of old scrap from UBCs 

(discussed in the section “Used Aluminum Beverage Cans”). 

Output from old scrap supply includes exports and unrecovered scrap with the balance going into current consumption 

(recycled). Import and export quantities are obtained from the 

trade statistics for iron and steel scrap. The quantity consumed 

is obtained from iron and steel scrap consumption data as provided by a USGS survey from which are deducted the 

amounts of consumption of home and prompt scrap. The number of manganese units in the quantity consumed was 210,000 

t. The amount of unrecovered scrap is estimated to be the difference needed to obtain a balance for supply of old scrap. 

Included in the right-hand part of figure 1 is the dissipative loss of 102,000 t of manganese from the manufacture 

and use of manganese-containing batteries and chemicals. 

This was the quantity obtained for 1998 from the USGS 

Manganese Ore and Products Survey of plants where batteries, EMD, or such manganese chemicals as manganese 

sulfate and potassium permanganate are made or that supplied manganese raw material that ultimately went into such 

items as animal feed and plant micronutrients. The battery 

total includes imports of manganese dioxide. The average 

lifetime of batteries and chemicals was assumed to be less 

than 1 year. 

RECYCLING EFFICIENCY FOR 

OLD SCRAP 

Recycling efficiency is the amount of scrap recovered 

and reused relative to the amount theoretically available to 

be recovered and reused. The recycling efficiency for manganese-bearing scrap is calculated to be 53 percent on the 

basis of the recycling of old iron and steel scrap plus a small 

amount of old UBC scrap. 

By using a different manganese material flow model, 

Gabler (1995, p. 19) estimated the amount of manganese 

contained in old scrap that was recycled to correspond to 12 

percent of the apparent consumption in 1990. The equivalent percentage is 28 percent for the flow model for 1998 

shown in figure 1. 

Recycling of iron and steel scrap has been going on for 

more than 200 years, and that of UBCs, for about 30 years. 

Nearly one-half of domestic steel production in 1998 was 

from plants based solely on the use of scrap. Recycling efficiency is expected to remain about the same for iron and 

steel scrap because of competition from alternative sources 

of iron units. The aluminum industry expects that the trend 

in recycling rate for UBCs will be a slow but gradual 

increase. For information on the recycling of iron and steel, 

see Fenton (in press). 
MANGANESE RECYCLING IN THE UNITED STATES IN 1998 H5 

Figure 2. U.S. manganese consumption, by end-use pattern, from 1979 through 1998. 

INFRASTRUCTURE 

No ore with a manganese content of more than 35 percent was mined domestically in 1998. Consequently, all primary units of manganese were obtained from either imported ore or ore released from Government stockpiles. 

The chief facility where manganese was smelted and/or 

extracted was near Marietta, Ohio, and was the only site 

where manganese ferroalloys were produced domestically. 

In 1998, this facility, which was operated by Elkem Metals 

Co., accounted for more than 50 percent of total U.S. consumption of manganese ore. Ownership of this facility 

changed in 1999 to France’s Eramet; it was renamed Eramet Marietta Inc. In 2000, annual production of manganese 

ferroalloys there was reported to be 65,000 t of silicomanganese and 104,000 t of various grades of ferromanganese 

(Platt’s Metals Week, 2000); manganese metal and EMD 

also were produced electrolytically at this site. Several other 

companies produced EMD—Eveready Battery Co. in Ohio, 

Kerr-McGee Chemical LLC in Mississippi, and Erachem 

Comilog, Inc. (formerly Chemetals Inc.), in Tennessee. 

Electrolytic metal was produced domestically at another site 

in Nevada (also Kerr-McGee). Subsequently, domestic production of manganese metal ended, first at Eramet Marietta 

in 2000 and then at Kerr-McGee in 2001. 

With regard to the infrastructure of iron and steel scrap 

recycling [discussed by Fenton (in press) in more detail], a 

large amount of scrap is generated by a multitude of firms 

and facilities located in the northern and eastern parts of the 

country. 

Monthly and annual reports of the USGS for Iron and 

Steel Scrap and for Aluminum provide details of foreign 

trade in scrap of these materials, especially trade of the 

United States. The United States historically has been a net 

exporter of iron and steel scrap. 

In chapter 81 of the Harmonized Tariff Schedule for 

U.S. imports, the part that pertains to “Other base metals”

contains a “Waste and scrap” subcategory (8111.00.3000) 

for manganese. The quantity of imports reported in this subcategory typically is about 200 t or less, most of which is 

from Canada. The nature of the material being reported 

under this subcategory is not well known and probably consists of various manganese-bearing drosses, residues, and 

steel and/or iron items or perhaps none of these. This material is not included within the manganese materials flow discussed in this report except that the 215 t of so-called manganese waste and scrap reported as having been imported is 

assigned an average manganese content of 50 percent and, 

on that basis, is included within total manganese imports. 
H6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

PROCESSING OF MANGANESE-BEARING 

SCRAP 

IRON AND STEEL SCRAP 

Of the 811,000 t of manganese units from stocks and 

imports that compose primary supply, 705,000 t goes into 

domestic production (figure 1). Domestic production 

includes the sequence of manufacturing steps that produce 

manganese ferroalloys and/or metal, raw steel in whose 

manufacture domestic plus imported ferroalloys and metal 

are consumed, and finally steel mill shapes that are shipped 

to fabricators or end users. By means of a balance between 

the total inputs and outputs for production that relate to iron 

and steel, the metallurgical loss or nonutilization of manganese was calculated to be 368,000 t. This signifies a loss 

rate of 52 percent, which is somewhat greater than the range 

of 40 to 50 percent that is presumed to apply for manganese 

loss in steelmaking in the 1990s (Jones, 1994, p. 15). The 

52-percent figure does not seem unreasonable, however, 

when one considers that it includes not only losses in steelmaking, but also those in the manufacture of ferroalloys and 

metal. Presumably, most of the manganese not ending up in 

product becomes a constituent of slag, at least some of 

which is usable. 

Most of the processing of iron and steel scrap takes 

place prior to its arrival at the steel plant. Operations at the 

steel plant consist of keeping scrap segregated according to 

its chemical and physical characteristics and cutting up 

bulky home scrap into more manageable pieces. Because of 

the high temperatures involved, iron and steel scrap is completely melted in the steelmaking operation. Refining typically includes an oxidation step; for example, by injection 

of gaseous oxygen. This causes the losses of carbon to gas 

and of some iron, manganese, and silicon to slag. The recycling model for iron and steel shows a processing loss for 

iron of 1 Mt, which is presumed to carry with it a manganese loss of 6,000 t, thus raising processing losses calculated so far to 374,000 t (Fenton, in press). 

Small amounts of iron and steel are unrecoverably lost 

through such dissipative causes as corrosion. Some old 

scrap can be regarded as temporarily unrecovered through 

its disposal in landfills or abandonment in place. The manganese units in unrecovered iron and steel scrap were estimated on the basis of the iron and steel model to be 

222,000 t. 

Following this model, the amount of old scrap generated (that is, the manganese content of the 75 Mt of iron and 

steel that became obsolete in 1998) was 450,000 t. As stated earlier in the section “Old Scrap Generated,” the weighted average recycling time was 19 years. The material savings from recycling of iron and steel scrap is estimated to be 

1 t of iron ore and 0.6 t of coal per metric ton of scrap recycled. The energy saved from recycling of iron and steel 

scrap was equivalent to that required to supply electricity to 

about one-fifth of domestic households (Fenton, in press). 

In view of its quality and known composition, home 

scrap within the steel plant is assumed to be recycled within 1 year of its generation. Similarly, new scrap generated 

during fabricating operations is relatively clean and of 

known composition and requires little preparation. Consequently, prompt scrap rapidly finds its way back to steel 

plants. This type of scrap is usually recycled directly; for 

example, from an automobile plant back to the steel plant 

from which the steel originally came. 

USED ALUMINUM BEVERAGE CANS 

Some of the quantities shown in figure 1 reflect the relatively small amounts of manganese recovered by recycling 

of UBCs. On a weight basis, 75 percent of aluminum beverage can (ABC) bodies are made from alloy 3004, and 22 

percent of lids, from alloy 5182. The nominal manganese 

content of alloy 3004 is 1.1 percent, and that of alloy 5182 

is 0.35 percent. The conditions for UBC recycling in 1998 

were taken to be the same as those that had been projected 

for 1997—average UBC manganese content of 0.92 percent 

and melt loss of 9.3 percent (Sanders and Trageser, 1990, p. 

197). Melt loss is the only source of manganese loss in UBC 

recycling; loss of manganese is not due to burn-off or vaporization (R.E. Sanders, Jr., Technical Consultant, Aluminum 

Company of America, oral commun., December 4, 2000). 

UBCs were processed in facilities dedicated to their recycling. 

The Aluminum Association estimated the net weight of 

new ABCs shipped in 1998 to be 3.09 billion pounds (1.4 

Mt) and the rate of their recycling to be 62.8 percent (Aluminum Association, Inc., 1999). At 0.92 percent, the manganese content of the quantity shipped is approximately 

12,900 t, which is assumed to be the quantity of old scrap 

eventually generated from this source. UBC recycling— 

from can shipment to use to disposal and recovery—takes 

place rather rapidly so that recovery is assumed to take 

place within the year of generation. At a recycling rate of 

62.8 percent, the manganese content of the old scrap recovered (consumed) is 8,100 t. The unrecovered quantity of 

manganese is 4,800 (12,900 minus 8,100) t, or a rounded 

5,000 t, which is only about 2 percent of total unrecovered 

old scrap. At a 9.3-percent melt loss rate, the loss in processing the 8,100 t of manganese recovered from UBCs in 

old scrap is about 750 t, or a rounded 1,000 t. Incorporation 

of this with the process losses mentioned in the “Iron and 

Steel Scrap” section increases the total processing loss of 

manganese to 375,000 t. 
MANGANESE RECYCLING IN THE UNITED STATES IN 1998 

SUMMARY AND OUTLOOK 

Trends in the recycling of manganese are largely determined by trends in the recycling of iron and steel, which has 

accounted for 85 to 90 percent of manganese consumption. 

Steel is the more-important industry with a production of 

about 10 times that for cast iron. Consequently, the majority of manganese consumption is accounted for by production of raw steel (primary shapes). 

The precipitous drop in manganese consumption 

between 1979 and 1982, which is shown in figure 2, is 

attributed mainly to a large decrease in raw steel production 

owing to adverse economic conditions and a significant 

decrease in the amount of manganese used per metric ton of 

steel produced. This decline in unit consumption was a gain 

from the adoption of new steelmaking technologies in the 

early 1980s, such as the use of combined blowing (Jones, 

1994, p. 36). After 1983, the trend in total manganese consumption has been similar to that for raw steel production 

(about 1.8-percent-per-year growth). Assuming no significant change in manganese unit consumption, forecasts of 

the International Iron and Steel Institute suggest that the 

annual growth rate for total manganese consumption during 

the coming decade will be no greater than that of the past 

one (Iron & Steelmaker, 1999). 

Figure 2 also shows that the distribution of manganese 

consumption among end uses has changed little with time. 

For the reasonably foreseeable future, this distribution pattern will remain about the same. Manganese consumption in 

batteries has been growing at a faster rate (about 6 percent 

per year) than steel-related uses but still accounts for less 

than 10 percent of total demand. 

Recycling of iron and steel scrap is a well-established 

component of domestic steel production. Supply of iron 

units for steel production now is about evenly divided 

between iron ore plus some scrap (integrated steelmaking) 

and all scrap except for a small proportion of direct-reduced 

iron [electric arc furnace (EAF) mills]. By 2000, the EAF 

process could be used in 47 percent of domestic steel production. Because the share of domestic steel production 

taken by EAF mills has been growing steadily, these mills 

could be the dominant process by 2010 (Stubbles, 2000). 

This will provide the motivation for maintaining domestic 

recycling of manganese-bearing iron and steel scrap. 

On a much smaller scale, recycling of UBCs has 

reduced the primary manganese requirement for aluminum 

beverage cans. Recycling of household batteries, which is 

an activity that is in its infancy, has the potential to make a 

small contribution to manganese recycling. One of the original motivations for battery recycling—preventing mercury 

loss to the environment—has been greatly diminished 

because deliberate additions of mercury to the battery mix 

are no longer made. 

H7 

From the standpoint of sustainable use of manganese, 

reducing manganese loss in metallurgical processing would 

appear to be a major subject for investigation and is always 

of interest as a way of cutting costs. The relations given in 

figure 1 indicate that almost one-half as much manganese is 

lost in metallurgical operations as is contained in products 

going into use. These relations also indicate that nearly 90 

percent of metallurgical losses were compensated for by the 

level of scrap recycling. Efforts to recover manganese from 

steelmaking slags date back to at least World War II, but 

development of a commercially feasible method has not 

been achieved nor seems likely to be for the foreseeable 

future (Jones, 1994, p. 29). A major difficulty is that the 

manganese content of steelmaking slags is relatively low 

(typically 7 percent or less). Significant quantities of iron 

and steel slags are used in construction and road building 

and for other purposes. These usages do not constitute a use 

of their manganese values per se. 

REFERENCES CITED 

Aluminum Association, Inc., 1999, Aluminum can recycling rate comes in at 62.8 percent for 1998: Washington, D.C., Aluminum Association, Inc., press release, 

March 26, 1 p. 

Fenton, M.D., 2000a, Iron and steel: U.S. Geological Survey Mineral Commodity Summaries 2000, p. 88–89. 

Fenton, M.D., 2000b, Iron and steel, in Metals and minerals: U.S. Geological Survey Minerals Yearbook 1998, v. 

I, p. 39.1–39.15. 

Fenton, M.D., 2000c, Iron and steel scrap, in Metals and 

minerals: U.S. Geological Survey Minerals Yearbook 

1998, v. I, p. 40.1–40.19. 

Fenton, M.D., in press, Iron and steel recycling in the United States in 1998: U.S. Geological Survey Circular 

1169–G. 

Ferlay, Serge, and Weill, Patric, 2000, Used batteries—A 

global solution: ITE Letters on Batteries, New Technologies & Medicine (with News), v. 1, no. 4, p. 

530–534. 

Gabler, R.C., Jr., 1995, A manganese consumption and recycling flow model: U.S. Bureau of Mines Information 

Circular 9421, 50 p. 

Iron & Steelmaker, 1999, Short- and medium-term outlook 

for steel demand: Iron & Steelmaker, v. 26, no. 12, p. 

41–44. 

Jones, T.S., 1994, Manganese material flow patterns: U.S. 

Bureau of Mines Information Circular 9399, 57 p. 

Jones, T.S., 1999, Manganese, in Plunkert, P.A., and Jones, 

T.S., comps., Metal prices in the United States through 

1998: U.S. Geological Survey, p. 83–86. 

Jones, T.S., 2000, Manganese, in Metals and minerals: U.S. 

Geological Survey Minerals Yearbook 1998, v. I, p. 

49.1–49.17. 
H8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Kirgin, K.H., 2000, Total U.S. casting demand forecast to 

contract in 2000: Modern Casting, v. 90, no. 1, p. 30–33. 

Platt’s Metals Week, 2000, Eramet shuts US manganese 

metal production: Platt’s Metals Week, v. 71, no. 30, 

July 24, p. 6–7. 

Sanders, R.E., Jr., and Trageser, A.B., 1990, Recycling of 

lightweight aluminum containers—Present and future 

perspectives, in Recycling of Metals and Engineered 

Materials, 2d, Williamsburg, Va., October 28–31, 1990, 

Proceedings: Warrendale, Pa., The Minerals, Metals & 

Materials Society, p. 187–201. 

Stubbles, John, 2000, EAF steelmaking—Past, present and 

future: Skillings Mining Review, v. 89, no. 43, October 

21, p. 4–5. 

Watson, N.J., Andersen, R.W., and Holt, G., 1998, Battery 

recycling in the metals industry from Europe to the 

USA, in International Seminar on Battery Waste Management, 10th, Deerfield Beach, Fla., October 26–28, 

1998, Proceedings: Boca Raton, Fla., Florida Educational Seminars Inc., unpaginated. 
MANGANESE RECYCLING IN THE UNITED STATES IN 1998 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle. 

downgraded scrap. Scrap intended for use in making a 

metal product of lower value than the metal product 

from which the scrap was derived. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

H9 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

primary metal commodity. Metal commodity produced or 

coproduced from metallic ore. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

secondary metal commodity. Metal commodity derived 

from or contained in scrap. 
U.S. Department of the Interior

U.S. Geological Survey

Columbium (Niobium) Recycling in the United States in 1998 

By Larry D. Cunningham 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–I

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Global Geologic Occurrence of Columbium . . . . . . . . . . . . . . . . . . . . . . . . . .1

Production and Production Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Sources of Columbium Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Disposition of Columbium Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6


Processing of Columbium-Bearing Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Iron and Steel Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Superalloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7


References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

FIGURES


1. Diagram showing U.S. columbium recycling flow in 1998 . . . . . . . . . . . . . . . . . . . I2 

2. Graph showing U.S. columbium consumption, by end-use sector, from 1979

through 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

TABLE


1. Salient statistics for U.S. columbium scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . .I3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

million metric tons (Mt) 1,102,000 short ton 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Columbium (Niobium) Recycling in the United States in 1998 

By Larry D. Cunningham 

ABSTRACT 

This report describes the flow of columbium (niobium) 

in the United States in 1998 with emphasis on the extent to 

which columbium was recycled/reused. Columbium was 

mostly recycled from products of columbium-bearing steels 

and superalloys; little was recovered from products specifically for their columbium content. In 1998, about 1,800 

metric tons of columbium was recycled/reused; about 55 

percent of that was derived from old scrap. The columbium 

recycling rate was calculated to be 22 percent, and columbium scrap recycling efficiency, 50 percent. 

INTRODUCTION 

As shown in figure 1, this materials flow study of 

columbium includes a description of columbium supply-anddemand factors for the United States in 1998 to illustrate the 

extent of columbium recycling1 to identify recycling trends. 

Columbium [niobium (Nb)] is a steel-gray ductile 

refractory metal that is used mostly as an alloying element 

in steels and superalloys. Columbium and niobium are 

synonymous names for the chemical element with atomic 

number 41—“columbium” was the name given in 1801, 

and “niobium” was the name officially designated by the 

International Union of Pure and Applied Chemistry in 1950. 

The metal conducts heat and electricity well, has a high 

melting point (about 2,470°C), is readily fabricated, and is 

highly resistant to many chemical environments. 

Salient columbium statistics are based on the columbium content of steel and superalloy scrap (table 1). In 1998, 

about 2,900 metric tons (t) of columbium contained in old 

scrap was generated; about 1,000 t of columbium valued at 

about $20 million was recycled/reused. The old scrap recycling efficiency was calculated to be about 50 percent, and 

the recycling rate was about 22 percent. Columbium contained in new scrap consumed was about 800 t. 

GLOBAL GEOLOGIC OCCURRENCE OF 

COLUMBIUM 

Columbium is almost always found in nature as an 

oxide in association with other minerals, but not in elemental form or as a sulfide. Columbium has an overall 

1Definitions for select words are found in the Appendix. 

crustal abundance estimated to be 20 parts per million and 

a strong geochemical affinity for tantalum. Pyrochlore 

[(Ca,Na)2

Nb2(O,OH,F)7] and bariopyrochlore (also known 

as pandaite), which is its barium analog, from Brazil and 

Canada have become the main sources of columbium. The 

minerals, which contain little tantalum, have a columbium 

oxide-to-tantalum oxide ratio of 200:1 or greater. The minerals are commonly found in the interior parts of alkaline 

igneous complexes, frequently in association with minerals 

of thorium, titanium, uranium, and rare-earth elements. In 

Brazil, the occurrences are in eluvial deposits that result 

from the weathering in place of carbonatites, which leaves 

an enriched concentration of apatite, bariopyrochlore, and 

magnetite. In Canada, the occurrences are in complex ring 

structures of carbonatite and alkaline rocks in the Precambrian Shield. Columbite and tantalite, which are similar in 

chemical composition and atomic structure, are the other 

principal columbium minerals. When columbium predominates over tantalum, the proper name for the mineral is 

“columbite” when the reverse is true, the proper name is 

“tantalite.” Columbite-tantalite, which is also known as 

coltan in some African countries, occurs mainly as an accessory mineral disseminated in granitic rocks or in pegmatites 

associated with granites. Columbite-tantalite is known to exist 

in all continents, but most deposits with high columbium or 

tantalum content are small and erratically distributed. In 

most cases, economic mineral concentrations have been 

produced by weathering of pegmatites and formation of 

residual or placer deposits (Parker and Adams, 1973; Cunningham, 1985; Crockett and Sutphin, 1993, p. 6-7). 

The largest columbium reserves and resources are located in Brazil where reserves are estimated to be more than 4 

million metric tons of contained columbium in pyrochlore 

deposits. Canada has the second largest columbium reserves 

in pyrochlore deposits; the reserves are estimated to be about 

140,000 t of contained columbium (Cunningham, 2002). 

U.S. columbium resources are of low grade, and none were 

considered to be economically minable in 1998. 

PRODUCTION AND PRODUCTION PROCESSES 

The United States, which has no columbium mining 

industry, must import all its columbium source materials for 

processing. Brazil and Canada, which are the world’s largest 

producers of columbium minerals, together account for more 

I1 
I2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 1. U.S. columbium materials flow in 1998. Values are in metric tons of contained columbium. 
COLUMBIUM (NIOBIUM) RECYCLING IN THE UNITED STATES IN 1998 I3 

Table 1. Salient statistics for U.S. columbium scrap in 1998. 

[Values in metric tons of contained columbium, unless otherwise 

specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,900 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,000 

Value of old scrap consumed3 . . . . . . . . . $20 million 

Recycling efficiency4 . . . . . . . . . . . . . . . . . 50 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,000 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,500 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . . . . 800 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . 44:56 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . 22 percent 

U.S. net exports of scrap10 . . . . . . . . . . . . . . . . . . . . . . 400 

Value of U.S. net exports of scrap . . . . . . . . . . . $6 million

1Columbium content of products theoretically becoming obsolete in 

the United States in 1998; this excludes dissipative uses. 

2Columbium content of products that were recycled in 1998. 

3Unit value of contained columbium in materials used in calculating 

total value of contained metal in scrap. 

4(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported). 

5Old scrap generated plus old scrap imported. 

6Old scrap generated plus old scrap imported minus old scrap 

consumed minus old scrap exported. 

7Including prompt industrial scrap but excluding home scrap. 

8Ratio of quantities consumed, in percent. 

9Fraction of the columbium apparent supply that is scrap, on an 

annual basis. 10Trade in scrap is assumed to be principally in old scrap. 

than 95% of total reported world production. Pyrochlore (produced in Brazil and Canada) is the columbium source material that is used to produce steelmaking-grade (regular-grade) 

ferrocolumbium. The remaining columbium mineral supply 

comes from the mining of columbite and columbite-tantalite 

mostly in Australia, Brazil, Nigeria, and other African countries. Brazil discontinued the export of pyrochlore in about 

1981 and now exports only upgraded/value-added columbium 

products, most of which is steelmaking-grade ferrocolumbium. Prior to 1994, the United States converted pyrochlore 

from Canada into steelmaking-grade ferrocolumbium. Beginning in late 1994, however, all pyrochlore produced in Canada was being converted to steelmaking-grade ferrocolumbium 

in that country. Thus, the United States does not produce steelmaking-grade ferrocolumbium from pyrochlore, and the U.S. 

steel industry requirements for ferrocolumbium are satisfied 

virtually entirely by imports. Brazil’s annual ferrocolumbium 

production capacity, which is mostly steelmaking grade, is 

estimated to be more than 30,000 t of contained columbium. 

In 1998, Brazil accounted for almost 80 percent of total U.S 

columbium imports. Canada’s annual capacity is estimated at 

about 2,200 t of contained columbium in steelmaking-grade 

ferrocolumbium. 

Pyrochlore is mined mainly by mechanized open pit or 

underground methods. An open pit is used in Brazil, and an 

underground mining method is used in Canada. Ore with host 

rock is usually dislodged from a working face with explosives. After the ore has been finely ground, it is beneficiated 

primarily by various flotation procedures combined with 

magnetic separation to remove iron minerals. A chloridizing 

and leaching process also can be used to lower barium, lead, 

phosphorus, and sulfur contents. Methods used to mine other 

columbium-bearing ores have ranged from simple hand operations in small pegmatite mines to hydraulic monitors and 

dredges at placer deposits. Aluminothermy is a process used 

for making steelmaking-grade ferrocolumbium from 

pyrochlore concentrates. A mixed charge of aluminum powder, iron oxide, pyrochlore concentrates, and slagging agents 

is reacted in a steel cylinder. Steelmaking-grade ferrocolumbium is also produced from pyrochlore in an electric 

furnace by using essentially the same reactants as in the aluminothermic process. Heat input can be better controlled 

with the electric furnace process, and columbium recovery is 

generally better than the aluminothermic process. The extraction of columbium from other columbium-bearing concentrates involves dissolution with hydrofluoric acid followed by 

liquid-liquid extraction with methyl isobutyl ketone (MIBK). 

This procedure efficiently recovers columbium in a form that 

can then be further processed into columbium oxide. 

Columbium oxide is aluminothermically reduced batchwise 

to produce high-purity ferrocolumbium, nickel columbium, 

and columbium metal. In some cases, the reactions are carried out in water-cooled copper reactors to avoid contamination by refractory materials. Aluminothermically produced 

columbium metal is commonly purified to remove aluminum 

and other contaminants by remelting it in an electron-beam 

furnace. Several remelts may be required before the desired 

level of purity is reached and a ductile ingot has been produced (Cunningham, 1985; Miller, Fantel, and Buckingham, 

1986, p. 8-10; Schlewitz, 1996, p. 46-49). 

USES 

The principal use for columbium is in the form of steelmaking-grade ferrocolumbium. Ferrocolumbium is typically 

available in grades that contain from 60 to 70 percent 

columbium. Steelmaking accounts for more than 80 percent 

per year of reported columbium consumption in the United 

States. In 1998, estimated percentages of end-uses for 

columbium in the United States were microalloyed steels, 

66; superalloys, 19; stainless steels, 14; and other, which 

includes superconducting materials, 1. The end-use patterns 

for columbium in the remainder of the world were similar to 

those of the United States with microalloyed steels being the 

predominant end-use sector (Tantalum-Niobium International Study Center, 1999b). In the 1960s and early 1970s, two 

significant events increased columbium use-the introduction 

of columbium as an important microalloying element in 
I4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

steel and the development of nickel-base alloys, which 

made use of columbium in alloys for jet engine components. 

U.S. columbium consumption during the past 20 years is

shown in figure 2. 

Columbium-bearing microalloyed steels are used in 

automobiles, buildings, bridges, oil and gas pipelines, and 

so forth, where the strength-to-weight and cost-per-unitstrength ratios are advantageous. In the automobile industry, 

the use/amount of high-strength columbium-containing 

steel has continued to increase despite the trend to reduce 

the total amount of steel in automobiles. Columbium-bearing high-strength low-alloy steels allow designers to save 

weight and to reduce fabrication cost. 

Because of its refractory nature, appreciable amounts 

of columbium in the form of high-purity ferrocolumbium 

and nickel columbium are used in cobalt-, iron-, and nickelbase superalloys for such applications as heat-resisting and 

combustion equipment, jet engine components, and rocket 

subassemblies. Columbium in superalloys strengthens the 

alloy at high service temperatures, such as in aircraft engine 

components. Most columbium-containing superalloys contain up to 2 percent columbium; some cobalt- and nickelbased superalloys, however, contain up to 6 percent 

columbium. 

Columbium and some of its alloys exhibit a lack of 

electrical resistance at very low temperatures (superconductivity) in such applications as magnetic resonance imaging 

(MRI) devices for medical diagnostics. Columbium carbide 

is used in cemented carbides to modify the properties of the 

cobalt-bonded tungsten carbide-base material to impart 

toughness and shock resistance. It is usually used along with 

carbides of other metals, such as tantalum and titanium, in 

drill bits, shovel teeth, tool bits, and other wear-resistant 

components; these are small end-use sectors for columbium. 

Columbium oxide is the intermediate product used in the 

manufacture of columbium carbide, columbium metal, 

high-purity ferrocolumbium, and nickel columbium. 

PRICES 

During the 1990s, the columbium price remained stable 

owing to the availability of columbium from Brazil and Canada. Brazil’s production of columbium concentrates, which is 

mostly pyrochlore, accounts for more than 85 percent of total 

world columbium production. As the dominant columbium 

producer/supplier, Brazil has maintained a marketing strategy 

of moderate price changes and stable supply. Events that had 

some impact on the columbium price during the 1990s 

included Brazil’s expansion of its ferrocolumbium production 

capacity, Canada’s startup of steelmaking-grade ferrocolumbium production, and initiation of sales of columbium 

materials from the National Defense Stockpile (Cunningham, 

1999). A price for Brazilian pyrochlore has not been available 

since 1981, and the published price for pyrochlore produced 

in Canada was discontinued in early 1989. 

Figure 2. U.S. columbium consumption, by end-use sector, from 1979 through 1998. 
COLUMBIUM (NIOBIUM) RECYCLING IN THE UNITED STATES IN 1998 I5 

The price of columbium is affected most by the availability of steelmaking-grade (regular-grade) ferrocolumbium produced from pyrochlore. In 1998, the American 

Metal Market published price for steelmaking-grade ferrocolumbium ranged from $6.75 to $7.00 per pound of contained columbium. The Metal Bulletin price for columbite 

ore, which is based on a minimum of 65 percent contained 

columbium oxide (Nb2O5) and tantalum oxide (Ta2O5), 

ranged from $2.80 to $3.20 per pound. The American 

Metal Market published price for high-purity (vacuumgrade) ferrocolumbium ranged from $17.50 to $18.00 per 

pound of contained columbium. Industry sources indicated 

that columbium metal products sold in the range of about 

$24 to $100 per pound in ingot and special shape forms, 

columbium oxide for master alloy production sold for 

about $8.80 per pound, and nickel columbium sold at about 

$18.50 per pound of contained columbium (Mining Journal, 1999; Tantalum-Niobium International Study Center, 

1999a). In 1998, no price for any type of columbium scrap 

was published. For this report, the price for columbium 

contained in steel scrap was taken to be the average published price for steelmaking-grade ferrocolumbium–about 

$6.90 per pound of contained columbium. The price for 

columbium contained in superalloy scrap was taken to be 

the average published price for high-purity ferrocolumbium and nickel columbium–about $18 per pound of contained columbium. 

SOURCES OF COLUMBIUM SCRAP 

Columbium in the form of steelmaking-grade ferrocolumbium is used as an additive in steelmaking to improve 

corrosion-resistance and strength characteristics in some 

steels. Less than 10 percent of steel produced in the world 

has been estimated to benefit from the advantages of 

columbium addition (Tantalum-Niobium International 

Study Center, 1993, p. 4; Roskill Information Services, 

1998, p. 110). 

In steelmaking, the addition of ferrocolumbium to the 

steel bath is accompanied by a number of chemical and 

physical processes. Ferrocolumbium is heated above its 

melting point, and the columbium dissolves into the liquid 

metal. After a period of time, the columbium is dissipated 

throughout the entire volume of the liquid steel in the bath 

by mass transfer processes (Lyakishev, Tulin, and Pliner, 

1984, p. 199). 

Although most columbium-containing steels comprise less than 0.1 percent columbium, some stainless 

steels can comprise as much as 1.25 percent columbium. 

A major market for columbium among stainless steels is 

in type 347, which contains about 0.8 percent columbium. 

Stainless steel scrap is almost always used to produce 

more stainless steel. The scrap is mainly recycled as 

either home or purchased scrap; demand is usually a function of demand for the stainless steel itself. Columbium 

mostly in the form of high-purity (vacuum-grade) ferrocolumbium and nickel columbium is added to cobalt- and 

nickel-base superalloys in such applications as jet engine 

components. The most important columbium-containing 

superalloy, nickel-base alloy Inconel 718, comprises 

about 5 percent columbium. Of the total superalloy scrap 

processed worldwide in 1996, about 70 percent was recycled into the same alloy; about 20 percent, downgraded; 

and the remaining 10 percent, sold to nickel refineries 

(ASM International, 1998). 

Although columbium is not recovered from the scrap 

steel and superalloys that contain it, recycling of these scrap 

materials is significant, and columbium content, where 

applicable, can be reused. Much of the columbium recycled 

in steel is diluted to tolerable levels; it effectively becomes 

a substitute for iron or other alloy metals rather than being 

used for its unique properties or is oxidized and removed in 

processing. New columbium-bearing scrap is generated 

mostly from manufacturing plants that produce steel products and fabricators of parts made from superalloys. This 

type of scrap is usually quickly returned to steel plants and 

superalloy meltors for remelting. Some major sources for 

old columbium-bearing scrap are junked automobiles (estimated 10-year lifetime) and scrap from discarded or obsolete parts made from superalloys (estimated 20-year lifetime), such as jet engine components. In 1998, columbium 

scrap sources consisted of steel scrap (estimated to be about 

70 percent of the total) and superalloy scrap (estimated to be 

about 30 percent of the total). A major end use for columbium has been in columbium-bearing high-strength low-alloy 

steels for oil and gas pipelines (estimated 60-year lifetime). 

These steels were introduced during the 1970s and will be a 

potential significant future source of columbium-bearing 

steel scrap. 

DISPOSITION OF COLUMBIUM SCRAP 

In 1998, the quantity of columbium recycled/reused 

from old scrap represented about 12 percent of domestic 

columbium supply. With no U.S. columbium mining industry, columbium-bearing old scrap is important to the 

columbium supply chain. Of the estimated 3,000 t of 

columbium contained in old scrap that was available for 

recycling in 1998, about 33 percent was used for domestic 

columbium supply, and about 50 percent was unrecovered. 

Most of the unrecovered material was in the form of steel 

scrap that was abandoned in place, lost to the environment, 

or shipped to landfills. Scrap that was abandoned or in landfills could possibly be recycled in the future. 

RECYCLING EFFICIENCY 

Most columbium is recycled/reused in the form of 

columbium-bearing steel and superalloy scrap. In 1998, a 

columbium recycling efficiency was estimated to have been 

about 50 percent compared with 52 percent for steel. 
I6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

INFRASTRUCTURE 

Although no columbium was mined in the United States 

in 1998, compounds, ferrocolumbium, metal, and other 

alloys were produced mostly by six companies. Cabot Performance Materials, Boyertown, Pa., had a production capability that ranged from raw material processing through to 

the production of columbium end products, H.C. Starck Inc., 

Newton, MA, was a supplier of columbium products, Kennametal, Inc., Latrobe, Pa., was a supplier of columbium carbides, Oremet-Wah Chang, Albany, Ore., and Reading 

Alloys, Inc., Robesonia, Pa., were major producers of highpurity columbium products, and Shieldalloy Metallurgical 

Corp., Newfield, N.J., was a producer of ferrocolumbium. 

Columbium consumption was mainly in the form of steelmaking-grade ferrocolumbium by the steel industry and 

high-purity columbium alloys and metal by aerospace-related industries with plants in the Eastern United States, the 

Midwestern United States, California, and Washington. 

Columbium is recycled mainly in the iron and steel and 

alloys-related industries. A companion report on steel recycling in this series discusses the infrastructure for the recycling of steel scrap (Fenton, in press). The largest concentration of recycling facilities is in the heavily populated 

northern and eastern regions of the country where steel 

product use and scrap generation are greatest. 

The superalloy recycling industry comprises mainly 

superalloy processors, scrap generators, scrap dealers, and 

scrap consumers. Scrap is generated when superalloys are 

produced, cast, or wrought into semifinished products, cut or 

ground into finished products, and when finished products 

become obsolete. The scrap is collected, sorted, cleaned, 

sized, and certified for chemical composition by a superalloy 

scrap processor before it reenters the superalloy-use cycle. 

The numerous material flow relations among superalloy 

scrap generators, collectors, dealers, processors, and brokers 

obscure the quantities of superalloy scrap that is available for 

recycling, that is downgraded, and that is imported or exported. Superalloy scrap recycling facilities are located mostly in 

the eastern and western regions of the country where the larger concentration of superalloy producers and end users is 

found (Papp, 1988). 

Trade in columbium scrap is relatively small, and data 

are not available. The U.S. International Trade Commission’s Harmonized Tariff Schedule System categorizes 

some selected columbium materials. The system, however, 

categorizes columbium waste and scrap in a nonspecific tariff classification, and, in 1998, no trade figures for import or 

export of columbium scrap were identified. The columbium 

content of columbium-bearing steel and superalloy scrap 

imports and exports, however, was estimated to be about 

100 t and 500 t, respectively, in 1998. 

The United States imports most of its columbium 

requirements. In 1998, U.S. imports of ferrocolumbium and 

columbium alloys, metal, and powders totaled about 5,450 t 

of contained columbium and were valued at about $83 million. Imports came mostly from Brazil and Canada. 

Columbium exports, mainly ferrocolumbium, totaled about 

20 t of contained columbium and were valued at more than 

$200,000. Germany and Mexico were the major recipients 

of the materials. 

PROCESSING OF COLUMBIUMBEARING SCRAP 

IRON AND STEEL SCRAP 

Scrap is collected by scrap dealers and processed into 

a physical form and chemical composition that can be consumed by steel mills in their furnaces. The shredder, which 

is the largest and most expensive piece of equipment used 

in recycling, fragments vehicles and other discarded steel 

into fist-sized pieces. Baling presses are used to compact 

the scrap into manageable bundles. Scrap dealers sort 

scrap materials, and steelmakers carefully purchase scrap 

that does not contain undesirable elements that exceed 

acceptable levels. The scrap is mainly melted in basic oxygen and electric arc furnaces. In the fabrication of new 

steel products, new steel scrap with known chemical composition is produced. Preparation of the new scrap for 

recycling is usually limited to cutting, cleaning, and baling 

prior to shipment back to the steelmaker. The processing 

of iron and steel scrap is discussed in Fenton (in press). 

Stainless steel is recycled in a similar manner as iron and 

steel scrap, but the volume of material is less, and the 

value is greater. Increased demand raises the value of 

scrap, which enables more scrap to be recycled. Scrap 

dealers compete for stainless steel on national and international bases, and the scrap may be handled at several locations before it is sold for use (ASM International, 1998). 

Scrap separated by alloy type usually brings the highest 

price. Balers are used to compress the scrap; shredders are 

rarely used. 

SUPERALLOYS 

Superalloys are alloys developed for high-temperature 

conditions where stresses (shock, tensile, thermal, or vibratory) are high and where resistance to oxidation is required. 

The processing of superalloy scrap can be difficult and 

complicated. Hundreds of superalloys contain more than 20 

alloying elements, and each element must be considered 

when designing and evaluating processes for separating 

and recovering the valuable metals. Each piece of superalloy scrap must be identified and its composition certified 

before it is sold. Turnings are degreased, fragmented, and 
COLUMBIUM (NIOBIUM) RECYCLING IN THE UNITED STATES IN 1998 I7 

compressed for remelting. Balers are used to compress 

superalloy scrap; shredders are rarely used. Superalloys are 

usually air melted or vacuum melted. Recycled scrap is 

acceptable for most air-melted alloys. Product specifications, however, usually prohibit the use of recycled scrap in 

vacuum-melted alloys to reduce the chance that detrimental impurities may be included in the final product, such as 

in critical components for jet engines. Owing to the high 

cost and/or periodic scarcity of superalloys, scrap recycling 

is used extensively (Gupta and Suri, 1994, p. 139-140; 

ASM International, 1998). 

Scrap is a preferred furnace charge for superalloy 

melters and can provide about 50 percent of a superalloy 

furnace charge. Scrap is prerefined, prealloyed, and easy to 

handle. New or home scrap turnings are the largest form of 

superalloy scrap. Vacuum-quality turnings are collected to 

produce a furnace-ready charge that can be easily melted. 

The first step is a qualitative verification of chemical purity to isolate severely contaminated material from chemically clean material. Turnings are crushed into chips, which 

are then cleaned of residual cutting fluids and dirt. Lot 

homogenization and certification follows; processed scrap 

is required to meet the same chemical requirements as the 

finished heat. In the case of alloy Inconel 718, which has a 

lower melting point than its constituents, using processed 

scrap in the melt saves on electrical costs and melting time 

(Lane, 1998). This scrap is then either remelted in the plant 

where it was originally produced (home scrap) or sold for 

remelting at another plant (new scrap). 

OUTLOOK 

A 20-year pattern of columbium consumption is shown 

in figure 2. The principal use for columbium is expected to 

continue as an additive in steelmaking, mostly in the manufacture of microalloyed steels used for automobiles, bridges, 

pipelines, and so forth. The production of high-strength lowalloy steel is the leading use for columbium, and the trend of 

columbium demand, domestically and globally, will continue to follow closely that of steel production. With about 80 

percent of columbium being consumed in steelmaking, 

columbium recycling trends will be determined most by 

trends in the recycling of steel, which is discussed in Fenton 

(in press). U.S. scrap supply was reported to be a function of 

market price, which affects the collection of obsolete scrap; 

levels of activity in the metalworking industry, which influences the generation of prompt industrial scrap; and melting 

activity, which impacts the availability of home scrap 

(American Metal Market, 2001). 

The outlook for columbium also will be dependent on 

the performance of the aerospace industry and its use of 

columbium-bearing alloys. Columbium consumption in the 

production of superalloys, which is the second largest end 

use for columbium, will be most dependent on the market 

for aircraft engines. Because nickel-base superalloys (such 

as alloy Inconel 718) can account for about 40 to 50 percent 

of engine weight, they are expected to be the materials of 

choice for the future owing to their high temperature operating capability (Tantalum-Niobium International Study 

Center, 1999b). Thus, the rate at which columbium is recycled will also depend upon the rate at which products that 

contain columbium-bearing superalloys are recycled. 
I8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

REFERENCES CITED


American Metal Market, 2001, Several factors seen transforming scrap industry: American Metal Market Metals 

Recycling Supplement, v. 109, no. 56, March 22, p. 

10A. 

ASM International, 1998, Recycling and life-cycle analysis—Recycling, in Metals handbook (2d ed.): Materials 

Park, Ohio, ASM International, p. 1182- 1187. 

Crockett, R.N., and Sutphin, D.M., 1993, International 

Strategic Minerals Inventory summary report—Niobium (columbium) and tantalum: U.S. Geological Survey 

Circular 930-M, 36 p. 

Cunningham, L.D., 1985, Columbium, in Mineral facts and 

problems: U.S. Bureau of Mines Bulletin 675, p. 185­

196. 

Cunningham, L.D., 1999, Columbium (niobium), in Plunkert, P.A., and Jones, T.S., comps., Metal prices in the 

United States through 1998: U.S. Geological Survey, p. 

35-38. 

Cunningham, L.D., 2002, Columbium (niobium): U.S. Geological Survey Mineral Commodity Summaries 2002, 

p. 52-53.

Fenton, M.D., in press, Iron and steel recycling in the United 

States in 1998: U.S. Geological Survey Circular 

1196–G. 

Gupta, C.K., and Suri, A.K., 1994, Extractive metallurgy of 

niobium: Boca Raton, Fla., CRC Press, Inc., 254 p. 

Lane, John, 1998, Recycling of superalloys for gas turbines, 

in Superalloys for gas turbines: Gorham’s International 

Business Conference, Tampa, Fla., June 15-17, 1998, 

Proceedings: Gorham, Me., Gorham Advanced Materials, Inc., individually paginated. 

Lyakishev, N.P., Tulin, N.A., and Pliner Yu.L., 1984, Niobium 

in steels and alloys: Sao Paulo, Brazil, Cia. Brasileira de 

Metalurgia e Mineração, 334 p. 

Miller, F.W., Fantel, R.J., and Buckingham, D.A., 1986, 

Columbium availability—Market economy countries— 

A minerals availability program appraisal: U.S. Bureau 

of Mines Information Circular 9085, 20 p. 

Mining Journal, 1999, Niobium: Mining Journal, Steel 

Industry Metals, Annual Review Supplement, v. 333, 

no. 8543, August 6, p. 78. 

Papp, J.F., 1988, Superalloy recycling 1976-1986, in Superalloys 1988—International Symposium on Superalloys, 

6th, Champion, Pa., September 18-22, 1988, Proceedings: Warrendale, Pa., The Metallurgical Society, Inc., 

p. 367-376.

Parker, R.L., and Adams, J.W., 1973, Niobium (columbium) 

and tantalum, in Brobst, D.A., and Pratt, W.P., eds., 

United States mineral resources: U.S. Geological Survey 

Professional Paper 820, p. 443-454. 

Roskill Information Services, 1998, The economics of niobium, 1998 (8th ed.): Roskill Information Services, 

238 p. 

Schlewitz, J.H., 1996, Niobium and niobium compounds, in 

Nickel and nickel alloys to paint, v. 17 of Kirk-Othmer 

encyclopedia of chemical technology (4th ed.): New 

York, John Wiley & Sons, p. 43-67. 

Tantalum-Niobium International Study Center, 1993, The 

niobium market and the effect of recent innovations in 

technology: Tantalum-Niobium International Study 

Center, no. 74, June, 10 p. 

Tantalum-Niobium International Study Center, 1999a, 

Overview of the tantalum and niobium industries for 

1998 and 1999: Tantalum-Niobium International Study 

Center, no. 100, December, 12 p. 

Tantalum-Niobium International Study Center, 1999b, 

Technical and commercial development of the European niobium market: Tantalum-Niobium International 

Study Center, no. 98, June, 8 p. 
COLUMBIUM (NIOBIUM) RECYCLING IN THE UNITED STATES IN 1998 I9 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle. 

downgraded scrap. Scrap intended for use in making a 

metal product of lower value than the metal product 

from which the scrap was derived. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

primary metal commodity. Metal commodity produced or 

coproduced from metallic ore. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

secondary metal commodity. Metal commodity derived 

from or contained in scrap. 
U.S. Department of the Interior

U.S. Geological Survey

Tantalum Recycling in the United States in 1998 

By Larry D. Cunningham 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–J

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Global Geologic Occurrence of Tantalum . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Production and Production Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Sources of Tantalum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Disposition of Tantalum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6


Processing of Tantalum-Bearing Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Cemented Carbides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Superalloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Electronic Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8


References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

FIGURES 

1. 	Diagram showing U.S. tantalum recycling flow in 1998 . . . . . . . . . . . . . . . . . . . . . J2 

2. 	Graph showing U.S. tantalum consumption, by end-use sector, from 1979 through


1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3. 	Graph showing yearend average tantalum concentrate price from 1979 through


1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

TABLE 

1. Salient statistics for U.S. tantalum scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . .J3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

million metric tons (Mt) 1,102,000 short ton 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Tantalum Recycling in the United States in 1998 

By Larry D. Cunningham 

ABSTRACT 

This report describes the flow of tantalum in the United 

States in 1998 with emphasis on the extent to which tantalum was either recycled or reused. Tantalum was recycled 

mostly from new scrap that was generated during the manufacture of tantalum-related electronic components and new 

and old scrap products of tantalum-containing cemented carbides and superalloys. In 1998, about 210 metric tons of tantalum was either recycled or reused, about 43 percent of 

which was derived from old scrap. The tantalum recycling 

rate was calculated to be 21 percent, and tantalum scrap 

recycling efficiency, 35 percent. 

INTRODUCTION 

As shown in figure 1, this materials flow study of tantalum includes a description of tantalum supply and 

demand factors for the United States in 1998 to illustrate 

the extent of tantalum recycling1 and to identify recycling 

trends. Figure 1 shows the tantalum recycling flow with 

domestic supply and distribution of domestic supply of 

primary and secondary tantalum in 1998. 

Tantalum (Ta), which was discovered in 1802, is a 

refractory metal that is ductile, easily fabricated, highly 

resistant to corrosion by acids, a good conductor of heat and 

electricity, and has a high melting point (about 3,000°C). 

The major use for tantalum, as tantalum metal powder, is in 

the production of electronic components, mainly tantalum 

capacitors. Alloyed with other metals, tantalum is also used 

in making cemented carbide tools for metalworking equipment and in the production of superalloys for jet engine 

components. 

Salient tantalum statistics are based mostly on the 

tantalum content of old cemented carbide and superalloy 

scrap (table 1). In 1998, about 300 metric tons (t) of tantalum contained in old scrap was generated, with about 90 

t of tantalum valued at about $8 million recycled or 

reused. The old scrap recycling efficiency was calculated 

to be about 35 percent, and the recycling rate, about 21 

percent. Tantalum contained in new scrap consumed was 

about 120 t. 

1Definitions for select words are found in the Appendix. 

GLOBAL GEOLOGIC OCCURRENCE OF 

TANTALUM 

The principal source of tantalum is an isomorphous 

series of minerals that contain columbium (niobium), iron, 

manganese, and tantalum oxides. Columbium and tantalum have a strong geochemical affinity for each other and 

are found together in most rocks and minerals in which 

they occur. Tantalite-columbite, which is the major source 

for tantalum, occurs mainly as accessory minerals disseminated in granitic rocks or in pegmatites associated with 

granites. When tantalum predominates over columbium, 

the proper name for the mineral is “tantalite”; when the 

reverse is true, the proper name is “columbite.” Economic 

mineral concentrations occur where weathering has led to 

residual or placer deposits, as in Nigeria or southeast Asia, 

or where the pegmatites contain a high concentration of 

these minerals, as in the Bernic Lake deposit in Manitoba, 

Canada. The microlite-pyrochlore mineral series is also a 

source of tantalum. These minerals consist essentially of 

complex oxides of calcium, columbium, sodium, and tantalum in combination with hydroxyl ions and fluoride(s). 

Microlite may contain as much as 70 percent tantalum 

oxide, and pyrochlore generally contains less than 10 percent. Microlite, which is often associated with tantalite or 

columbite, occurs mainly in the albitized zones of granite 

pegmatites. Struverite, which is a titanium-bearing oxide, 

is a low-grade source of tantalum that is recovered from 

tin-mining wastes in southeast Asia. Struverite typically 

contains about 12 percent each of columbium and tantalum oxides (Cunningham, 1985; Crockett and Sutphin, 

1993, p. 6-7). 

Tantalum resources and reserves occur mainly in pegmatite deposits in Australia, Brazil, Canada, and several 

African countries. The largest tantalum reserves and 

resources are located in Australia where reserves are estimated to be about 36,000 t of contained tantalum. Canadian tantalum reserves are estimated to contain more than 

3,000 t of contained tantalum. Brazil’s tantalum reserve 

base is estimated to contain about 53,000 t of contained tantalum (Cunningham, 2002). U.S. tantalum resources are of 

low grade, and none were considered to be economically 

minable in 1998. 

J1 
J2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

U.S. tantalum Figure 1. materials flow in 1998. Values are in metric tons contained tantalum. 
TANTALUM RECYCLING IN THE UNITED STATES IN 1998 

Table 1. Salient statistics for U.S. tantalum scrap in 1998. 

[Values in metric tons of contained tantalum, unless otherwise 

specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 

Consumption value3 . . . . . . . . . . . . . . . . . . $8 million 

Recycling efficiency4 . . . . . . . . . . . . . . . . . 35 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . . . . 120 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . 57:43 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . 21 percent 

U.S. net imports of scrap10 . . . . . . . . . . . . . . . . . . . . . . 30 

Value of U.S. net imports of scrap . . . . . . . . . $2.7 million

1Tantalum content of products theoretically becoming obsolete in the 

United States in 1998. It excludes dissipative uses. 

2Tantalum content of products that were recycled in 1998. 

3Unit value of contained tantalum in materials used in calculating total 

value of contained metal in scrap. 

4(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported). 

5Old scrap generated plus old scrap imported. 

6Old scrap generated plus old scrap imported minus old scrap consumed minus old scrap exported. 

7Including prompt industrial scrap, but excluding home scrap. 

8Ratio of quantities consumed, in percent. 

9Fraction of the tantalum apparent supply that is scrap, on an annual 

basis. 

10Trade in scrap is assumed to be principally in old scrap. 

PRODUCTION AND PRODUCTION PROCESSES 

The United States, which has no tantalum mining 

industry, must import all its tantalum source materials for 

processing. Tantalum mineral production comes mostly 

from columbite and tantalite mining operations in Australia, Brazil, and Canada and from smaller mining operations in several African countries. Australia, which is the 

largest producer, accounts for about 25 percent of the 

world’s annual tantalum requirements. In 2002, Australia’s Sons of Gwalia Ltd. total tantalum production 

capacity at its Greenbushes and Wodgina Mines was 

about 850 t of contained tantalum in mineral concentrate. 

Tantalum is also obtained from low- and high-grade tantalum-bearing tin slags, which are byproducts from tin 

smelting, principally from Asia, Australia, and Brazil. 

Low-grade tin slags, however, must first be treated by a 

pyrometallurgical technique to upgrade them to a synthetic concentrate before delivery to the tantalum extraction 

plant; this upgrading operation is performed in Germany. 

In past years, tantalum-containing tin slags were an 

important source of tantalum supply. Owing to structural 

J3 

changes in the tin industry, however, their importance has 

decreased with the exception of accumulated inventory. 

Thus, future tantalum supply will have a greater dependence on natural sources, such as tantalite-columbite. 

Most tantalum-related mining operations in the past 

generally were small, relatively high-cost, intermittent 

operations that depended on the recovery of byproduct or 

coproduct minerals for economic viability. Mine development, however, has shifted more to primary tantalum 

sources, notably in Australia. Alluvial and residual tantalum and tantalum-containing tin deposits are normally 

mined by dredges, hand, hydraulic monitors, or mechanized open pit mining. The mining of pegmatite deposits, 

which may be either open pit or underground, is carried 

out by blasting, transporting, and crushing the rock to 

free the tantalum and associated coproduct minerals. The 

materials are then concentrated by wet gravity methods 

(jigs, sluices, spirals, and tables) and finally separated 

from associated minerals by gravity and electromagnetic 

and electrostatic processes. The extraction of tantalum 

from tantalum source materials involves dissolution with 

hydrofluoric acid followed by liquid-liquid extraction 

with methyl isobutyl ketone (MIBK). This procedure 

efficiently recovers tantalum in a form that can then be 

further processed into potassium fluotantalate and tantalum oxide. Potassium fluotantalate is reduced with 

metallic sodium to produce tantalum metal powder. The 

tantalum metal powder produced by the sodium reduction process is treated to convert the metal to a form suitable for use as capacitor-grade powder and as feedstock 

for tantalum sheet and wire. A solid-state reaction 

between tantalum oxide and carbon under vacuum conditions produces tantalum carbide (Cunningham, 1985; 

Tripp, 1997, p. 660-669). 

USES 

The principal end use for tantalum is in the production 

of electronic components, mainly in tantalum capacitors. 

In 1998, estimated end-uses for tantalum in the United 

States were electronic components, 65 percent; machinery, 

21 percent; transportation, 9 percent; and other, 5 percent. 

U.S. tantalum consumption during the past 20 years is

shown in figure 2. 

Faced with runaway tantalum source material prices 

during the late 1970s and early 1980s, processors were 

forced to pass along a large part of the price increases to 

end users, which had the effect of a decrease in the use of 

tantalum. Because of escalating tantalum prices, consumers 

began to substitute alternate products, to decrease tantalum 

content in products, and to increase recycling to substitute 

for virgin tantalum products. In the consumer electronics 

sector, tantalum was designed out of some circuits and 

replaced primarily with aluminum-bearing electronic 

components. 
J4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

FigurFigure 2. U.S. tantalum consumption, by end-use sector, from 1978 through 1998. 

A significant spike in tantalum demand occurred in 

1984. U.S. factory sales of tantalum capacitors were at an 

alltime high. The computer and automotive markets were 

experiencing steady growth that fostered a need for greater 

miniaturization without sacrificing tantalum capacitor performance. In 1985, demand for tantalum capacitors from 

computer manufacturers declined significantly. Tantalum 

for cemented carbides also decreased owing to the growing 

popularity of coated cutting tools and the automotive industry’s emphasis on producing smaller vehicles that require 

less metal cutting. 

During the 1990s, the demand for tantalum was 

strong; consumption increased in most years. Demand for 

tantalum capacitors was robust in such electronics sector 

products as automotive electronics, pagers, personal computers, portable telephones, and video cameras. Overall 

growth in this sector, however, was slowed owing to the 

industry’s continued emphasis on the miniaturization of 

electronic components, which resulted in less tantalum 

used per unit. The tantalum capacitor exhibits reliable performance and combines compactness and high efficiency 

with good shelf life. 

Because of its high melting point (about 3,000°C), 

good strength at elevated temperatures, and good corrosion 

resistance, tantalum is combined with cobalt, iron, and 

nickel to produce superalloys that are used in aerospace 

structures and jet engine components. Tantalum carbide, 

which is used mostly in mixtures with carbides of such 

metals as columbium, titanium, and tungsten, is used in 

boring tools, cemented-carbide cutting tools, farm tools, 

and turning and wear-resistant parts. Owing to tantalum’s 

excellent corrosion-resistant properties, tantalum mill and 

fabricated products are used for corrosion and heat-resistant chemical plant equipment, such as condensers, evaporators, heat exchangers, heating elements, and liners for 

pumps and reactors. 

PRICES 

Tantalum mineral concentrates (tantalite) are the main 

primary source of tantalum, and the price for tantalum 

products is affected most by events in the supply of and 

demand for tantalite. The price for tantalum metal products 

generally follows the pattern for that of tantalum concentrates. The price for tantalum metal products is also affected by the size of the order or contract and the material 

specification. Events that had some impact on the tantalum 

price during the 1990s include robust demand for tantalum 

capacitors in the electronics sector, long-term tantalum 

mineral supply contracts between major producers and 

processors, and initiation of sales of tantalum materials 

from the National Defense Stockpile (Cunningham, 

1999). 
TANTALUM RECYCLING IN THE UNITED STATES IN 1998	 J5 

Figure 3 shows trends in the yearend average tantalum 

concentrate price from 1979 to 1998. Between 1979 and 

1980, the price for tantalum source materials exploded, 

and production could not meet market demand, which 

resulted in sustained inventory reduction. With optimistic 

forecasts of market growth, processors found themselves 

locked into a bidding contest for available tantalum source 

materials. By yearend 1982, large high-cost inventories of 

tantalum source materials were accumulated as a hedge 

against perceived future shortages. By 1988, price increases for tantalum source materials were again of major concern in the tantalum industry. The yearend 1988 price for 

tantalite ore nearly doubled the yearend 1987 price. The 

price escalation was attributed to increased demand for 

tantalum source materials following a drawdown of the 

tantalum inventories that had been built up. The price for 

tantalum ore continued its cyclic pattern through 1993; 

thereafter, the price was steady with some moderate 

increases. 

In 1998, the Platt’s Metals Week spot price for tantalite 

ore, which was based on contained Ta2

O5, f.o.b. U.S. ports, 

began the year at a range of $32 to $34 per pound, rose to a 

range of $33 to $35 per pound in March, and remained at 

that level through December. For the year, the Metal Bulletin published price for tantalite ranged from $28.00 to 

$31.50 per pound of contained Ta2O5, and that for Greenbushes tantalite, Australia, which was based on 40% contained Ta O5

, was $40 per pound. 2

Industry sources indicated that the average selling 

prices per pound tantalum content for some tantalum products were as follows: capacitor wire, $180 to $270; capacitor-grade powder, $135 to $260; and vacuum-grade metal 

for superalloys, $75 to $100 (Mining Journal, 1999). In 

1998, no public price for tantalum scrap was published. For 

this report, the price for tantalum contained in tantalumbearing scrap was taken to be the average published price for 

tantalite ore (about $33.80 per pound of contained Ta2

O5). 

SOURCES OF TANTALUM SCRAP 

The value of tantalum is a driving force for its recycling. The major end use, which is more than 60 percent in 

the production of electronic components, is mainly in tantalum capacitors. The amount of tantalum recycled from finished electronic components (old scrap), however, is very 

small because this source has not yet been fully developed. 

New scrap materials reclaimed at manufacturing plants that 

produce tantalum-related electronic components are a major 

source of tantalum supply and are delivered back to tantalum processors for recycling (Tantalum-Niobium International Study Center, 1996). 

Tantalum carbide is used mostly in the manufacture 

of cemented carbide inserts and tools for metal cutting 

and metalworking applications. Tools for metal cutting 

(an estimated 1-year or less lifetime) account for an estimated 30 percent of total demand for cemented carbides. 

Figure 3.	 Yearend average tantalum concentrate price from 1978 through 1998. 

Values are in current dollars per pound contained pentoxide. (Source: 

Metals Week, 1979–92, and Platt’s Metals Week, 1993–98). 
J6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Cutting tool insert demand is dependent on the demand 

for and sales of durable goods, such as automobiles, which 

accounts for an estimated 40 percent of total cutting tool 

consumption. The cemented carbide inserts typically contain about 3 percent tantalum. Events that affect the use of 

cutting tools include the use of coatings, such as titanium 

carbide, which increases cutting tool efficiency; increased 

use of ceramic tools; and net-shape-metal-forming processes that reduce the need for metal cutting (Santhanam, 1992; 

Roskill Information Services Ltd., 1999). 

Superalloys are nickel- and cobalt-base materials used 

to make heat-resistant gas-turbine engine parts. These alloys 

are developed for high-temperature conditions where stresses (shock, tensile, thermal, and vibratory) are relatively high 

and where resistance to oxidation is required. Nickel-base 

superalloys are more widely used than cobalt-base superalloys. Tantalum is added to nickel-base superalloys to 

increase overall strength and to improve the oxidation 

resistance of the alloy. The first major use for tantalum in 

superalloys was in those alloys that contained up to 4 percent tantalum for use in jet engine turbine blades in the early 

1970s. In the 1980s, single-crystal-casting techniques led to 

the commercialization of Pratt & Whitney’s nickel-based 

single crystal alloy, PWA 1480, which contains about 12 

percent tantalum. Although tantalum is not recovered from 

the superalloy scrap that contains it, recycling of superalloy 

scrap is significant, and tantalum content, where applicable, 

can be reused. New tantalum-bearing scrap is generated 

from fabricators of parts made from superalloys. This type 

of scrap is usually quickly returned to superalloy melters for 

remelting. Some major sources for old tantalum-bearing 

scrap are discarded or obsolete parts made from superalloys, 

mostly jet engine components (an estimated 20-year lifetime). Of the total superalloy scrap processed worldwide in 

1996, about 70 percent was recycled into the same alloy; 

about 20 percent, downgraded; and the remaining 10 percent, sold to nickel refineries (Tantalum-Niobium International Study Center, 1982; ASM International, 1998). 

DISPOSITION OF TANTALUM SCRAP 

In 1998, the quantity of tantalum recycled or reused 

from old scrap represented about 7 percent of domestic tantalum supply. Because the United States has no tantalum 

mining industry, tantalum-bearing old scrap is a welcome 

addition to the tantalum supply chain. Of the estimated 370 

t of tantalum contained in old scrap that was available for 

recycling in 1998, about 65 percent was unrecovered; about 

24 percent, used for domestic tantalum supply; and the 

remainder, exported. Most of the unrecovered material was 

in the form of finished electronic equipment. Recycling of 

tantalum from old and/or discarded tantalum-containing 

electronic equipment has not been developed or used to any 

significant degree. 

RECYCLING EFFICIENCY 

Recycling efficiency shows the relation between what 

is theoretically available for recycling and what was recovered and not recovered. This relation is defined as the 

amount of old scrap consumed plus old scrap exports divided by the sum of old scrap generated and old scrap imports 

plus or minus old scrap stock changes, as applicable. Most 

tantalum is either recycled or reused in the form of superalloy and tantalum-bearing cemented carbide scrap. A tantalum recycling efficiency of about 35 percent was estimated 

to have been reached in 1998. The recycling efficiency 

would have been higher if not for the lack of a concerted 

program to reuse tantalum from its major end use, electronic components. 

INFRASTRUCTURE 

No tantalum was mined in the United States in 1998. 

Metal, alloys, and compounds, however, were produced 

mostly by three companies by using tantalum units obtained 

from imported tantalum-bearing concentrates and metal and 

from domestic and foreign scrap. Cabot Performance Materials, Boyertown, PA, had a production capability that 

ranged from raw material processing through to the production of tantalum end products; H.C. Starck Inc., Newton, 

MA, was a major supplier of tantalum products; and Kennametal Inc., Latrobe, PA, was a supplier of tantalum carbide. Tantalum consumption was mainly in the form of 

alloys, compounds, fabricated forms, ingot, metal, and 

powder in the cemented carbide, electronics, and superalloy 

sectors. 

PM Recovery Inc. of Harrison, NY, which has been in 

operation since 1978, sorted, cleaned, and repackaged tungsten carbide and tantalum scrap at its Belfast, TN, facility. 

Hard-metal scrap, turnings, and sludges processed at the 

plant total about 900 metric tons per year (t/yr) (Cassidy, 

2001). High-Temp Specialty Metals Inc., Willingboro, NJ, 

which was founded in 1983, was involved in the physical 

and chemical cleaning of molybdenum, tungsten, and tantalum scrap. Scrap was deoiled with water, soap, and orange 

oil. Leachates were evaporated, and salts were treated by 

E. I. du Pont de Nemours & Co. at its Deepwater, NJ, plant. 

Hi-Temp also leached tantalum capacitors to remove manganese and processed them to Ta2

O . Amlon Metals Inc. 5

recycled about 200,000 t/yr of metal-bearing materials, 

which included tantalum; the company, which was founded 

about 1950, maintained offices in Australia, Brazil, China, 

India, Mexico, South Africa, Spain, Tanzania, the United 

States, and the United Kingdom (Cassidy, 2001). ECS 

Refining of Terrell, TX, was active in the recycling of electronic scrap, which included integrated circuits and circuit 

boards. Components were either reused or processed for 

their metal content (Mossholder, 2001). 
TANTALUM RECYCLING IN THE UNITED STATES IN 1998 J7 

The U.S. International Trade Commission’s Harmonized Tariff Schedule System categorizes some selected tantalum materials. The United States imports a significant 

amount of its tantalum requirements. In 1998, imports of 

tantalum metal and alloys totaled about 207 t of contained 

tantalum valued at about $56 million. Imports came mostly 

from China, Japan, and Thailand. Imports that were categorized as “waste and scrap” contained an estimated 70 t of 

tantalum scrap; China, Japan, and the United Kingdom were 

the major suppliers. Exports of tantalum metal and alloys 

totaled about 250 t of contained tantalum valued at about 

$72 million. Germany, Israel, Japan, and the United Kingdom were the major recipients of the materials. Exports of 

tantalum waste and scrap contained an estimated 40 t of tantalum with most of the material going to Germany, Hong 

Kong, Taiwan, and the United Kingdom. 

PROCESSING OF TANTALUM-BEARING 

SCRAP 

CEMENTED CARBIDES 

The emphasis for recycling most cemented carbide 

scrap is to recover the contained tungsten. There is value, 

however, in the recovery of other metals, such as tantalum. 

The choice of the process for recycling cemented carbide 

scrap depends on the concentration of tungsten, other metals, and the purity of the scrap. Recycling is accomplished 

by using mostly chemical or zinc processing methods. In the 

chemical process, carbide scrap with different contents of 

various metals, such as tantalum, are treated chemically to 

extract the tungsten and cobalt values first. The contained 

tantalum is collected in an oxide sludge, which is suitable as 

source material for the tantalum extraction plant (see section 

“Production and Production Processes”). The advantage to 

this process is that almost any type of cemented carbide 

scrap can be reused and that the resultant product is equivalent to virgin material (Tantalum-Niobium International 

Study Center, 1984; Stjernberg and Johnson, 1998). 

The zinc process uses hard scrap, such as used tool 

inserts, as the source material. This process is not a purification process, and careful sorting and pretreatment to 

remove oil, solder, and refractory coatings is essential for 

satisfactory reclamation. Zinc treatment dissolves the binder 

phase of the cemented carbide without changing the base 

phase of the material. The composition of the carbide is 

conserved, and the treated carbide can be reused in a new 

batch of cemented carbides that requires the same or similar 

composition. At elevated temperatures, zinc metal is added 

to the scrap source material in a vacuum furnace, which 

results in a breakdown of the hard metal structure, thus 

allowing conversion into a powder form. Zinc is removed 

from the powder by distillation, and the powder can then be 

used directly in a blend with virgin carbides to manufacture 

cemented carbide parts (Tantalum-Niobium International 

Study Center, 1984, 1996). The zinc process is less expensive than the chemical process, generates no waste products, 

and produces a powder that is essentially ready for use. The 

chemical and the zinc processes complement each other, 

and this results in the better use of tantalum source materials. Excluding some special applications, cemented carbide 

scrap is recycled either by the chemical process (about 35 

percent) or the zinc process (about 25 percent); the remaining material is not recycled (Tantalum-Niobium International Study Center, 1984; Stjernberg and Johnson, 1998). 

SUPERALLOYS 

The processing of superalloy scrap can be difficult and 

complicated. Hundreds of superalloys contain more than 20 

alloying elements, and each element must be considered 

when designing and evaluating processes for separating and 

recovering the valuable metals. Each piece of superalloy 

scrap must be identified and its composition certified before 

it is sold. Turnings are degreased, fragmented, and compressed for remelting. Balers are used to compress superalloy scrap; shredders are rarely used. Superalloys are usually air melted or vacuum melted. Recycled scrap is acceptable for most air-melted alloys. Product specifications, 

however, usually prohibit the use of recycled scrap in vacuum-melted alloys to reduce the chance that detrimental 

impurities may be included in the final product, such as critical components for jet engines. Owing to the high cost 

and/or periodic scarcity of superalloys, scrap recycling is 

used extensively (Gupta and Suri, 1994, p. 139-140; ASM 

International, 1998). Scrap is a preferred furnace charge for 

superalloy melters and can provide about 50 percent of a 

superalloy furnace charge. Scrap is prerefined, prealloyed, 

and easy to handle. New scrap turnings are the largest form 

of superalloy scrap. Vacuum-quality turnings are collected 

to produce a furnace-ready charge that can be easily melted. 

The first step is a qualitative verification of chemical purity 

to isolate severely contaminated material from chemically 

clean material. Turnings are crushed into chips, which are 

then cleaned of residual cutting fluids and dirt. Lot homogenization and certification follows; processed scrap is 

required to meet the same chemical requirements as the finished heat (Lane, 1998). 

ELECTRONIC COMPONENTS 

Although more than 60 percent of the tantalum that is 

consumed in the United States is in the electronics sector, 

the amount of tantalum recovered from obsolete electronic 

equipment is small. The trend toward higher capacitance 

tantalum powders and capacitor miniaturization promotes 

the use of less tantalum in products. Miniaturization, however, increases the amount of labor involved in recovery and 

results in less tantalum to be recovered when tantalum-bearing products are disassembled and recycled. One company 

processed capacitors by first leaching to remove manganese. 
J8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

The capacitors were then disintegrated by hydriding in 

a retort and calcined to Ta O5 (Cassidy, 2001). Computers, 2

which are a major end use for tantalum, have a life span, 

which includes reuse, of up to 7 years at which time their 

materials must be recycled or disposed of. By 2005, about 

64 million computers will have reached the end of their usefulness. Recycling of computers, however, can be difficult 

because they contain a number of recyclable materials, 

some of which present environmental problems on disposal. 

Such materials as lead solder and mercury are common in 

most electronics. Computer and electronic equipment 

account for only about 1 percent of the total waste generated in the United States, but an estimated 70 percent of heavy 

metals that go to landfills results from this 1 percent 

(Resource Recycling, 2000a, b, 2001). 

A small amount of workable used computers will be 

sold and reused through the resale market, and some will be 

donated to schools and nonprofit organizations. Demanufacturing, which is the disassembly of obsolete products, is 

one method to recycle electronic equipment, such as computers. In North America, more than 300 facilities harvest 

such computer components as hard drives and circuit 

boards for resale value. Demanufacturing can be profitable, 

but barriers, such as the lack of an adequate collection 

infrastructure, limited and cyclical markets for recovered 

materials, and products that are not designed to be disassembled and recycled, exist. A major source of material for 

demanufacturing is institutions that frequently update 

equipment owing to software updates and technology 

requirements. Shredding is another option that can be used 

to recycle computer equipment. Components, which range 

from laptops to mainframes, can be shredded, and the 

materials, separated. This is an efficient way to recycle 

large volumes of computers, such as units formerly leased 

to businesses (Recycling Today, 2000; Resource Recycling, 

2000a, b; Mossholder, 2001; U.S. Geological Survey, 

2001). 

OUTLOOK 

A 20-year pattern of U.S. tantalum consumption is shown 

in figure 2. The principal use (more than 60 percent) for tantalum as tantalum metal powder and wire in the production of 

electronic components, mainly tantalum capacitors, is expected to continue. This market sector is expected to be stimulated by the growth in the use of mobile telephones, which have 

a lifecycle of less than 2 years (Metal Bulletin Monthly, 

2001). Each phone may contain from 10 to 20 capacitors. 

Development of tantalum recycling (old scrap) in the electronics sector, however, is very limited and represents a major 

potential for future tantalum recycling. Tantalum recycling in 

this area will have to be part of a total recycling concept for 

electronic equipment, which will require time and major 

effort and cooperation between the tantalum industry and the 

electronics equipment recyclers. 

Concerns, factors, and issues that relate to disposal of 

obsolete and/or discarded electronic equipment include the 

need for a plan for the disposition of stored surplus equipment and the disposition of the increasing volume of equipment being sold; State government initiatives that affect 

electronic equipment disposition; loss of offshore processing and/or recycling capacity; and the logistics for the collection and transport of used equipment to scrap processors 

or recyclers (Resource Recycling, 2000a). Although the 

United States has no mandatory electronic take back or 

recycling program, certain U.S. computer manufacturers 

have voluntary internal recycling programs to handle some 

leased and purchased equipment. Legislation in the European Union (EU), however, set new standards for sale of 

electronic equipment in Europe; this includes equipment 

manufactured outside the region. The EU directives require 

companies to take back and recycle their electronic equipment and to phase out the use of various heavy metals, such 

as lead, in new equipment by 2008 (Metal Bulletin Monthly, 2001; Recycling Today, 2001). 

Tantalum carbide in the metal-cutting industry will be 

dependent on the growth of the general economy and is 

expected to grow at an estimated 2 percent per year. Tantalum consumption in superalloys, mostly in the aircraft 

industry, is expected to grow by about 3 percent per year 

(Tantalum-Niobium International Study Center, 1996, 1998; 

Mining Journal, 2000). The rate at which tantalum is recycled in the carbide and superalloy sectors will depend on the 

rate at which tantalum-containing cemented carbides and 

superalloys are recycled. 
TANTALUM RECYCLING IN THE UNITED STATES IN 1998 

REFERENCES CITED


ASM International, 1998, Recycling and life-cycle analysis—Recycling, in Metals handbook (2d ed.): Materials Park, Ohio, ASM International, p. 1182- 1187. 

Cassidy, D.J., 2001, U.S. plants operated solely to recycle 

metal-rich wastes: Recycling Metals From Industrial 

Waste—A Three Day Short Course and Workshop with 

Emphasis on Plant Practice, Golden, Colo., June 19-21, 

2001, Presentation, unpaginated. 

Crockett, R.N., and Sutphin, D.M., 1993, International 

Strategic Minerals Inventory summary report—Niobium (columbium) and tantalum: U.S. Geological Survey 

Circular 930-M, 36 p. 

Cunningham, L.D., 1985, Columbium, in Mineral facts 

and problems: U.S. Bureau of Mines Bulletin 675, 

p. 811-822.

Cunningham, L.D., 1999, Tantalum, in Plunkert, P.A., and 

Jones, T.S., comps., Metal prices in the United States 

through 1998: U.S. Geological Survey, p. 143-145. 

Cunningham, L.D., 2002, Tantalum: U.S. Geological Survey 

Mineral Commodity Summaries 2002, p. 166-167. 

Gupta, C.K., and Suri, A.K., 1994, Extractive metallurgy of 

niobium: Boca Raton, Fla., CRC Press, Inc., 254 p. 

Lane, John, 1998, Recycling of superalloys for gas turbines, 

in Superalloys for gas turbines: Gorham’s International 

Business Conference, Tampa, Fla., June 15-17, 1998, 

Proceedings, individually paginated. 

Metal Bulletin Monthly, 2001, Electronic scrap—A growing resource: Metal Bulletin Monthly, no. 366, June, 

p. 21-24.

Mining Journal, 1999, Tantalum: Mining Journal Speciality 

Metals Annual Review Supplement, v. 333, no. 8544, 

August 13, p. 89. 

Mining Journal, 2000, Tantalum comes of age: Mining 

Journal, v. 334, no. 8583, May 19, p. 391, 393. 

Mossholder, Nelson, 2001, Recycling electronic scrap: 

Recycling Metals from Industrial Waste—A Three Day 

Short Course and Workshop with Emphasis on Plant 

Practice, Golden, Colo., June 19-21, 2001, Presentation, unpaginated. 

Recycling Today, 2000, Electronics recycling—Re-boot 

re-use recycle: Recycling Today, v. 38, no. 4, April, 

p. 48-56.

J9 

Recycling Today, 2001, Electronics recycling—Bring it on: 

Recycling Today, v. 39, no. 4, April, p. 56-64. 

Resource Recycling, 2000a, Closing the circuit on electronics recycling: Resource Recycling, v. 19, no. 6, June, 

p. 22-27.

Resource Recycling, 2000b, Demanufacturing—The emergence of an urban industry: Resource Recycling, v. 19, 

no. 2, February, p. 36-38. 

Resource Recycling, 2001, Design for environment—A last 

will and testament for scrap electronics: Resource 

Recycling, v. 20, no. 3, March, p. 14-23. 

Roskill Information Services Ltd., 1999, The economics of 

tantalum (7th ed.): Roskill Information Services, 

p. 151-157.

Santhanam, A.T., 1992, Cemented carbides, in Bearing 

materials to carbon, v. 4 of Kirk-Othmer encyclopedia 

of chemical technology (4th ed.): New York, John 

Wiley & Sons, p. 848-860. 

Stjernberg, Klas, and Johnson, John, 1998, Recycling of 

cemented carbides: International Conference on Powder Metallurgy & Particulate Materials, Las Vegas, 

Nev., May 31-June 4, 1998, p. 1-173–1-179. 

Tantalum-Niobium International Study Center, 1982, Use of 

tantalum in superalloys: Tantalum-Niobium International Study Center, no. 31, September, 6 p. 

Tantalum-Niobium International Study Center, 1984, Production and properties of tantalum carbide and mixed 

carbides, influence of scrap reclamation: Tantalum-Niobium International Study Center, no. 39, August, 8 p. 

Tantalum-Niobium International Study Center, 1996, Recycling of tantalum: Tantalum-Niobium International 

Study Center, no. 86, June, 12 p. 

Tantalum-Niobium International Study Center, 1998, Tantalum supply and demand: Tantalum-Niobium International Study Center, no. 96, December, 12 p. 

Tripp, T.B., 1997, Tantalum and tantalum compounds, 	in 

Sugar to thin films, v. 23 of Kirk-Othmer encyclopedia 

of chemical technology (4th ed.): New York, John 

Wiley & Sons, p. 658-679. 

U.S. Geological Survey, 2001, Obsolete computers, “gold 

mine,” or high-tech trash?—Resource recovery from 

recycling: U.S. Geological Survey Fact Sheet 060-01, 

July, 4 p. 
J10 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle. 

downgraded scrap. Scrap intended for use in making a 

metal product of lower value than the metal product 

from which the scrap was derived. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

primary metal commodity. Metal commodity produced or 

coproduced from metallic ore. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

secondary metal commodity. Metal commodity derived 

from or contained in scrap. 
U.S. Department of the Interior

U.S. Geological Survey

Tin Recycling in the United States in 1998 

By James F. Carlin, Jr. 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–K

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES

III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . K1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Global Geologic Occurrence of Tin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

The Production Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Tin Market Prices and Use Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Tin Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Sources of Tin Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Old Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

New Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Disposition of Tin Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Infrastructure of Tin Scrap Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Processing of Scrap Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6


References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FIGURES 

1. 	Diagram showing U.S. tin materials flow in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . K2 

2. 	Graph showing U.S. tin consumption, by end-use sector, from 1978 through


1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

TABLE 

1. Salient statistics for U.S. tin scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .K3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

million metric ton (Mt) 1,102,001 short ton 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Tin Recycling in the United States in 1998 

By James F. Carlin, Jr. 

ABSTRACT 

This materials flow study includes a description of tin 

supply and demand factors for the United States to illustrate 

the extent of tin recycling and to identify recycling trends. 

Understanding, the flow of materials from source to ultimate 

disposition can assist in improving the management of the use 

of natural resources in a manner that is compatible with sound 

environmental practices. The quantity of tin recycled in 1998 

as a percentage of apparent tin supply was estimated to be 

about 22 percent, and recycling efficiency was estimated to be 

75 percent. Of the total tin consumed in products for the U.S. 

market in 1998, an estimated 12 percent was consumed in 

products where the tin was not recyclable (dissipative uses). 

INTRODUCTION 

This materials flow study includes descriptions of 

trends in consumption, losses, and recycling1 of tin and tinbearing materials in the United States in 1998. Of the 

approximately 76,000 metric tons (t) of tin consumed in 

fabrication in the United States in 1998, fabrication losses 

were estimated to be about 1,000 t, or about 1 percent. 

Because tin has been one of the higher valued base metals and because the infrastructure to reclaim tin in the United States has been well-developed for many years, tin has 

had significant recycling rates, though lower than for some 

other metals. Recycling is especially important for tin 

because virtually all the domestic primary tin requirements 

have long been dependent on imports. Historically, the United States has had only a few small tin mines that have supplied a minuscule portion of domestic tin needs. Tin imports 

and sales of tin from the U.S. National Defense Stockpile 

have provided most of the Nation’s primary tin needs for 

many years. The reclamation of scrap tin, however, has 

helped to reduce reliance on the Stockpile and foreign suppliers. The recycling rate for tin was estimated to be about 

22 percent in 1998. 

In 1998, tin imports in the form of metal or compounds 

amounted to 44,000 t, and exports of tin metal/compounds 

were approximately 5,000 t. No data are available on 

imports or exports of tin scrap. Imports were estimated to be 

nil, and exports were estimated to be 1 t. 

1Definitions for selected words are found in the Appendix. 

Old scrap consumed was 7,710 t; old scrap recycling 

efficiency was determined to be about 75 percent; new 

(prompt) scrap consumption amounted to 8,390 t. The value 

of this total scrap use was about $130 million. 

Figure 1 shows the domestic flow of tin in 1998 with 

the flow of recycled tin shown in detail. Figure 2 shows 

domestic tin usage for the past 20 years. 

GLOBAL GEOLOGIC OCCURRENCE OF TIN 

Tin is a relatively scarce element with an average 

abundance in the Earth’s crust of about 2 parts per million 

(ppm) compared with 94 ppm for zinc, 63 ppm for copper, 

and 12 ppm for lead (Lee and Yao, 1970). Tin is produced 

from lode (hard-rock) deposits and placer deposits derived 

from the lodes. The tin mineral cassiterite (SnO,) is the 

source of most tin production; a notable exception is the 

complex tin sulfide minerals in the subvolcanic or tin-silver 

lode deposits in Bolivia. Cassiterite has a high specific 

gravity (6.8-7. 1) and a Moh’s scale hardness of 6 to 7 and 

is usually a dark-brown or black color with an adamantine 

luster. 

Most lode tin deposits occur as greisen, replacement, 

skarn, or vein type deposits associated with granitic rocks or 

their extrusive equivalents where tin has been concentrated 

by magmatic differentiation processes (Sainsbury and Reed, 

1973; Taylor, 1979, p. 1-12). Placer deposits of several types 

have been derived from lode tin deposits by weathering and 

erosion. Because cassiterite is heavy and chemically resistant, it is concentrated by weathering in place, which 

removes lighter minerals (residual placers), or by erosional 

processes on a slope (eluvial placers) or in streams (alluvial 

placers). Marine tin placers are formed when tin minerals 

are concentrated in stream channels or along beaches and 

then submerged as a result of sea-level changes (Sainsbury, 

1969, p. 6-8). 

Much of the world’s past tin production has been from 

placer deposits, which generally can be mined more cheaply than lode deposits (Bleiwas and others, 1986, p. 33). 

From 1934 through 1987, Malaysia, Indonesia, and Thailand accounted for more than one-half of the world’s 10 million metric tons of tin production by using major dredge 

production from marine placer deposits (Sutphin and others, 

1990, p. 20). 

K1 
K2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

U.S. tin Figure 1. materials flow in 1998. Values are in metric tons contained tin. 
TIN RECYCLING IN THE UNITED STATES IN 1998 K3 

Table 1. Salient statistics for U.S. tin scrap in 1998. 

[Values in thousand metric tons of contained tin, unless otherwise specified; NA, not available] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Consumption value3 . . . . . . . . . . . . . . . . . $65 million 

Recycling efficiency4 . . . . . . . . . . . . . . . . . 75 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . 50:50 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . 22 percent 

U.S. net exports of scrap10 . . . . . . . . . . . . . . . . . . . . . . . 5 

Value of U.S. net exports of scrap . . . . . . . . . . . . . . . . NA 

1Tin content of products theoretically becoming obsolete in the United 

States in 1998. It excludes dissipative uses. 

2Tin content of products that were recycled in 1998. 

3Based on tin scrap price, estimated from composite metal prices 

reported by Platts Metals Week. Values of tin scrap imports and exports are 

reported by the U.S. Census Bureau. 

4(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported minus old scrap stock increase). 

5Old scrap generated plus old scrap imported plus old scrap stock 

decrease. 

6Old scrap supply minus old scrap consumed minus old scrap exported minus old scrap stock increase. 

7Prompt industrial scrap. Some scrap is excluded. 

8Ratio of quantities consumed, in percent. 

9Supply fraction that is scrap, on an annual basis. It is defined as (old 

plus new scrap consumed) divided by apparent supply [primary plus secondary production (old scrap plus new scrap) plus imports minus exports 

plus adjustment for Government and industry stock changes]. 

10Trade in scrap is assumed to be principally in old scrap. 

In 2000, China, Peru, and Bolivia accounted for about 

63 percent of the world tin production of 200,000 t in 2000 

by producing tin from lode deposits. Placer production 

made up the remaining 37 percent , of which Indonesia 

accounted for two-thirds (Carlin, 2001b). 

World reserve data indicate that China (lode deposits, 

26 percent of world reserves), Brazil (placer, 23 percent), 

Malaysia (placer, 13 percent), and Indonesia (placer, 8 percent) may be expected to play major roles in future tin production. Identified resources of tin in lode and placer 

deposits in the United States are an insignificant part of 

world totals (Sainsbury and Reed, 1973). Undiscovered lode 

tin resources in Alaska’s Seward Peninsula, if explored for 

and discovered, would probably add only modest increases 

to future domestic production (Reed and others, 1989). 

Small quantities of tin concentrate have been produced from 

placer deposits in Alaska and as a byproduct of molybdenum mining in Colorado and New Mexico (Carlin, 1985). 

The last reported production of tin in the United States was 

in 1994. 

TIN PRODUCTION PROCESSES 

Each type of tin deposit has its own characteristic processing technique. The crude tin concentrate from placer 

mining is upgraded by washing, tabling, and magnetic or 

electrostatic separation. The final product is virtually pure 

cassiterite. 

Tin ore from lode deposits is reduced to the necessary 

size by conventional crushing and grinding. The ore is concentrated by gravity methods that involve screening, classification, jigging, and tabling. The concentrate is usually a 

lower grade than placer concentrate owing to associated sulfide minerals. The sulfide minerals are removed by flotation 

or magnetic separation, with or without roasting. 

Cassiterite in placer deposits is fairly coarse-grained, 

and recoveries range from 90 percent for gravel-pump 

mines to 95 percent for dredging operations. The cassiterite 

in vein deposits, however, is typically very fine grained and 

is difficult to recover by gravity concentration. Cassiterite 

ore at lode mines in Australia and Bolivia are floated, but 

recoveries are seldom above 70 percent. Recovery of the tin 

content in Bolivia has been reported to be as little as 50 percent (Pearce, 1980, p. 755). 

Cassiterite is reduced to tin by heating with carbon at 

1,200 to 1,300 C. The almost pure cassiterite concentrate 

from placer deposits is smelted directly. Other concentrates, particularly from Bolivia, contain impurities that 

must be removed before smelting. This is usually done by 

roasting the tin concentrates with or without fluxes and followed by acid leaching. During roasting, most of the sulfur 

and arsenic are removed as oxides. Bismuth, copper, iron, 

and zinc oxides are removed by leaching the roasted concentrate with sodium carbonate or sulfate and leaching with 

water. Antimony, bismuth, lead, and silver are removed by 

a chloridizing roast followed by an acid leach. 

In tin smelting plants, reverberatory furnaces are used 

to smelt primary tin concentrate and to resmelt slag for additional tin recovery. Blast and electric furnaces are often preferred because of better control, cleaner slags, and superior 

efficiency in smelting finely divided materials. Electric furnaces may be favored for energy-saving reasons at some 

operations, especially smaller smelters. 

Tin smelting is a batch operation. A typical charge consists of cassiterite concentrate, a carbon reducing agent, and 

limestone and silica fluxes. Between 10 and 12 hours are 

required to smelt a charge. When smelting is complete, the 

molten batch is tapped into a settler from which the slag 

overflows into cast-iron pots. The molten tin from the bottom of the settler is cast into slabs or pigs for refining 

(Pearce, 1980, p. 766-768). 

TIN MARKET PRICES AND USE PATTERNS 

The price of tin is the most important factor that influences its recycling rate. In recent decades, tin generally has 

been the highest priced base metal. Although almost 20 
K4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 2. U.S. tin consumption, by end-use sector, from 1978 through 1998. 

years have passed since tin reached its historical peak price 

of more than $8 per pound, its recent pricing in the $2.50 to 

$4.00 range still provides an adequate incentive to recycle. 

The price for tin metal did not vary much throughout 

1998. The average composite price for the year, $3.73 per 

pound, was 2 percent lower than that of 1997. The London 

Metal Exchange (LME) was the primary trading arena for 

tin. Tin was only one of six metals (along with aluminum, 

copper, lead, nickel, and zinc) to be traded on the LME. The 

Kuala Lumpur Commodities Exchange in Malaysia, continued as an active tin-trading forum (Platt’s Metals Week, 

1999). 

In 1998, estimated uses of tin in the United States were 

cans and containers, 30 percent; electrical, 20 percent; construction, 10 percent; transportation, 10 percent; and other, 

30 percent (Carlin, 2001b). These tin usage patterns are similar to those in the rest of the world (Carlin, 2000; Roskill 

Information Services Ltd., 1995, p. 156-170); Figure 2 

shows total (primary and secondary) domestic tin consumption by end-use sector between 1978 and 1998. 

TIN STATISTICS 

Several sources of statistics on U.S. tin materials flow 

were used in this report to identify recycling parameters as 

well as the ultimate direction and disposition of domestic 

secondary supplies. Many of the tin data in this report have 

been extracted from U.S. Geological Survey (USGS) surveys 

of all known domestic firms that mine, smelt, use, import, 

and export tin or engage in scrap-tin recovery. A high percentage of those firms supply data; estimates are made for the 

remainder. Most other information in this study that relates to 

production, supply, consumption, and scrap activity was 

obtained from USGS publications and industry contacts. 

Table 1 and figure 1 present tin scrap data and recycling 

flow information used in this study. 

SOURCES OF TIN SCRAP 

Because tin was not produced in the United States in 

1998, sources of old scrap and new scrap are key elements 

of U.S. tin material flow. All scrap tin in the United States 

is derived from domestic sources; no foreign sources have 

been reported. In 1998, sources of new scrap and old scrap 

consumed accounted for equal amounts of secondary tin 

(8,000 t) in U.S. markets. 

OLD SCRAP GENERATED 

Old scrap consists of tin-containing products, such as 

tin cans and electronic equipment, that have been discarded 

after use. Old scrap is sometimes also referred to as “postconsumer scrap.” The old scrap generated in 1998 totaled 

13,000 t. Approximately 60 percent of this amount was 

reused during the year; the remainder was not recovered or 

was exported or added to industry stocks. 

NEW SCRAP GENERATED 

New scrap is tin waste that is generated during manufacturing processes and, for the most part, remains the property of the manufacturers; it is continually being recirculated. Home scrap is new scrap that is immediately redirected 

back into the manufacturing process without leaving the 
TIN RECYCLING IN THE UNITED STATES IN 1998 K5 

plant. Some new scrap is collected and later sold to scrap 

dealers who resell it to similar manufacturers. An example 

of new tin scrap would be the side trimmings made on a coil 

of tinplate (tinplate is essentially 99 percent flat-rolled steel 

with about a 0.5 percent-by-weight flash of tin coating on 

each side) in a steel mill to meet a customer’s width specification; other examples include the tin cans rejected in a 

canmaking plant owing to poor quality, such as low tin coating weight or insufficient rigidity. In 1998, 8,000 t of new 

tin scrap was reused, which represented about one-half of 

the total scrap consumed. 

DISPOSITION OF TIN SCRAP 

Because of the relatively high value of tin compared 

with other base metals, such as copper, lead, and zinc, the 

domestic tin consuming and tin recycling industries have 

become more efficient in recapturing discarded tin products. 

Also, because of its value, tin often been the target of smuggling attempts in areas that range from tin smelter sites in 

developing countries to scrapyard sites in the United States. 

Smuggling has been especially prevalent at times when tin 

prices reached high levels. Tin has generally been considered to be a nontoxic material. Thus, environmental considerations are not major factors in recycling. 

OLD SCRAP RECYCLING EFFICIENCY 

The recycling efficiency of old tin scrap is substantial 

despite the fact that its recycling rate is relatively low. Old 

scrap recycling efficiency, which is the amount recovered 

and reused relative to the total amount of old scrap generated and theoretically available for recycling, was 75 percent 

in 1998, whereas the recycling rate was 22 percent. The 

lower recycling rate was partly due to the fact that the third 

leading use for tin (tin chemicals) has end uses that are nearly all dissipative. 

INFRASTRUCTURE OF TIN SCRAP 

INDUSTRY 

Tin has not been mined in the United States for several 

years. During the past decade, a few small tin mines, most 

of which are in Alaska, have satisfied only a small fraction 

of domestic demand. TexTin Corp., which was the only 

domestic tin smelter, operated for decades in Texas City, 

Tex.; it closed in 1989 because it was unable to economically compete for foreign tin concentrates. For most of its 

history, the United States has depended on tin imports, Government stockpile sales, and recycled tin scrap for its industrial requirements (Defense National Stockpile Center, 

1998). 

In 1998, scrap tin was generated domestically at 5 

detinning plants and 46 secondary non ferrous-metal-processing plants. Old tin scrap was collected at hundreds of 

scrapyards, the five detinning plants, and most municipal 

collection-recycling centers. New scrap was generated 

mainly in the tin mills at six steel plants and at scores of 

canmaking facilities. Most tin-scrap-processing plants are 

close to tin-using industries in major market areas, most of 

which are in the Midwest and the Northeastern United 

States. 

Detinning facilities are unique to the tin scrap industry 

because no other major metal industry has numerous largescale plants designed to remove metal plating. Detinning 

operations are performed on new tinplate scrap from tin 

mills and canmaking plants and from old scrap in the form 

of used (postconsumer) tin cans. 

The domestic metals recycling industry, as a whole, has 

been undergoing substantial consolidation during the past 

30 years. Before consolidation, the industry was characterized by a multitude of small, family-run firms, many of 

which dated back to the 19th century. Usually, the firms 

operated only locally or perhaps regionally. From 1970 

onward, however, the industry has been characterized by 

fewer, larger units that serve national or international markets. 

The Steel Recycling Institute (SRI), which is funded by 

the Nation’s major steel producers, has promoted the recycling of used tin cans for more than a decade. These used tin 

cans have become an important raw material for the domestic steel industry during the past 20 years. According to the 

SRI, the steel can recycling rate had grown to 56 percent in 

1998 from 15 percent in 1988. The increased recycling is 

significant to tin recovery because most steel cans are made 

from tinplate (Steel Recycling Institute, 1999). 

Major domestic tin requirements have long been met by 

imports of primary refined tin. In recent years, Brazil has 

generally been the leading source followed by Indonesia, 

Bolivia, and China. Trade in tin scrap is relatively small, and 

trade figures are not available. No imports of tin scrap in 

1998 were identified. The United States exported relatively 

small quantities of new and old tin scrap. 

PROCESSING OF SCRAP METALS 

Typically, the alloys of tin, such as brass and bronze, 

jeweler’s metal, or babbitt, contain from 2 percent to 11 percent of tin as a minor component of the alloy. The major 

exception is solder. Solders for plumbing and constructionrelated uses have traditionally been 50 percent tin-50 percent lead, and those for electronics have usually been 70 

percent tin-30 percent lead. The bulk of the secondary tin 

industry processes various alloy forms of tin (brass, bronze, 

and solder); the recovered tin is recycled within its own 

product-line industries and, thus, is used again in alloys. 

The scrap materials of all alloys of tin are collected via 

long-established commercial routes and transported back to 

the original makers of the alloys. Typically, these alloy producers then use a mix of primary tin along with the primary 

element(s) of the other component(s) of the alloy and com­
K6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

bine them in a batch heating process with the collected scrap 

materials to produce new units of the same alloys. Thus, the 

secondary tin industry is essentially involved in a process of 

successive regeneration with old and new scrap alloys being 

mixed with some primary material added for each new generation of alloys. 

For most of this century, detinning has been the only 

process in the secondary tin industry through which tin 

alone, not in alloys, reached the marketplace. Consequently, 

detinning of tinplate is one of the most important sources of 

tin scrap in the United States. Tinplate scrap suitable for 

detinning is accumulated at various stages—off-specification tinplate generated in the tin mills at steel plants, reject 

tinplate and tin cans generated at canmaking facilities, reject 

cans at can-filling operations, and old scrap tin cans collected by municipalities via curbside collection programs. 

These collected forms of new and old tinplate scrap are 

transported to five domestic detinning plants. There, they 

are immersed in a heated sodium hydroxide solution, which 

is a batch process that is essentially the reverse of the original tin electroplating process. Tin ions leave the steel surface and migrate to an electrically charged cathode where 

they deposit and form a bar of tin. The detinned steel is then 

sold to scrap steel markets, most notably to be used as a 

scrap charge in the electric furnaces of steel minimills. The 

bars of scrap tin are then sold to appropriate users of secondary tin, such as producers of tin chemicals, firms that use 

tin to hot dip onto copper wire, makers of brass and bronze 

ingots, and the vast number of manufacturers of tin alloy. 

Traditionally, scrap tin is not used to make tinplate because 

of purity requirements. The tin coating thickness on steel in 

modem tinplate is only about, on average, one-half to onethird of what it was in the early 1960s. Today, the nominal 

tin coating thickness on each side of tinplate is only 

0.000381 millimeters. Thus, the economics of detinning 

make it not nearly as profitable as it once was. Nevertheless, 

for maximum steel cleanliness, some steel producers prefer 

to pay more to have tinplate scrap detinned before they use 

it; the presence of tin on the surface of scrap steel often is 

considered to be a major detriment to good quality steel 

(Groetsch and others, 1984). 

OUTLOOK 

The established stable consumption pattern of tin and 

the relatively high price of tin compared with that of other 

base metals indicates that plentiful amounts of tin will be 

available for recycling in future years. Moreover, the almost 

total U.S. reliance on tin imports, the planned elimination of 

Government tin stocks, and the expected technological 

advances will tend to encourage more recycling of tin in the 

next few decades. In addition, the United States will, most 

likely, continue to be the leading source of scrap for domestic tin markets. Except for dissipative uses, tin scrap for 

recycling will continue to come from all consumption sectors. Tin prices probably will remain as the most important 

influence on further recycling advances (Carlin, 1985; 

Roddy, 1995, p. 84-85). 

Trends toward consolidation in the recycling industry 

are expected to continue, at least in the near future. The 

resulting larger enterprises presumably will be able to 

attract funds more easily for equipment modernization and 

technological improvement that often lead to lower unit processing costs. Thus, consolidation trends augur well for 

increased recycling of tin. The recycling of tin enhances the 

sustainability of tin production by reducing the need for primary production, thereby saving energy and extending the 

longevity of natural resources. The prospects for increasing 

the recycling rate for tin chemicals are not particularly 

good, however, because tin chemicals are mostly a dissipative end use. Additionally, some of the more promising new 

uses for tin, such as ammunition, are essentially dissipative 

(Carlin, 2001a). 
TIN RECYCLING IN THE UNITED STATES IN 1998 

REFERENCES CITED


Bleiwas, D.I., Sabin, A.E., and Peterson, G.R., 1986, Tin availability-Market economy countries, in A minerals availability 

program appraisal: U.S. Bureau of Mines Information Circular 9086, p. 1–50. 

Carlin, J.F., Jr., 1985, Tin, in Mineral facts and problems: U.S. 

Bureau of Mines Bulletin 675, p. 847–858. 

Carlin, J.F., Jr., 2000, Tin, in Metals and minerals: U.S. Geological 

Survey Minerals Yearbook 1998, v. I, p. 78.1–78.13. 

Carlin, J.F., Jr., 2001a, Tin, in Metals and minerals: U.S. Geological Survey Minerals Yearbook 1999, v. I, p. 78.1–78.13. 

Carlin, J.F., Jr., 2001b, Tin: U.S. Geological Survey Mineral Commodity Summaries 2001, p. 172–173. 

Defense National Stockpile Center, 1998, Fiscal year 1998 stockpile disposals: Fort Belvoir, Va., Defense National Stockpile 

Center press release, October 25, 2 p. 

Groetsch, J.G., Gabler, R.C., Jr., and Wilson, D.A., 1984, Electrolytic stripping of tin in an acid fluoborate electrolyte: U.S. 

Bureau of Mines Report of Investigations 8887, 9 p. 

Lee, Tan, and Yao, Chi-lung, 1970, Abundance of chemical elements in the earth’s crust and its major tectonic units: International Geology Reviews, v. 12, no. 7, p. 778–786. 

Pearce, S.C., 1980, Developments in the smelting and refining of 

tin—Proceedings of the World Symposium on Metallurgy 

and Environmental Control, Las Vegas, Nev, February 24–28, 

1980: Las Vegas, Nev., The Metallurgical Society, American 

Institute of Mining, Metallurgical, and Petroleum Engineers, 

p. 754–769.

K7 

Platt’s Metals Week, 1999, Annual metal averages for 1998: Platt’s 

Metals Week, v. 70, no. 8, February 22, p. 4. 

Reed, B.L., Menzie, W.D., McDermott, M., Root, D.H., Scott, W., 

and Drew, L.J., 1989, Undiscovered lode tin resources of the 

Seward Peninsula, Alaska: Economic Geology, v. 84, no. 7, 

November, p. 1936–1947. 

Roddy, Peter, 1995, The international tin trade: Cambridge, United Kingdom, Woodhead Publishing Ltd., 263 p. 

Roskill Information Services Ltd., 1995, The economics of tin: 

London, United Kingdom, Roskill Information Services, 

Ltd., 290 p. 

Sainsbury, C.L., 1969, Tin resources of the world: U.S. Geological 

Survey Bulletin 1301, 55 p. 

Sainsbury, C.L., and Reed, B.L., 1973, Tin, in Brobst, D.A., and 

Pratt, W.P., eds., United States mineral resources: U.S. Geological Survey Professional Paper 820, p. 637–651. 

Steel Recycling Institute, 1999, Steel trade associations announce 

new strategic partnership: Pittsburgh, Pa., Steel Recycling 

Institute news release, January 25, 1 p. 

Sutphin, D.M., Sabin, A.E., and Reed, B.L., 1990, International 

Strategic Minerals Inventory summary report—Tin: U.S. 

Geological Survey Circular 930-J, 52 p. 

Taylor, R.G., 1979, Geology of tin deposits, in no. 11 of Developments in economic geology: New York, Elsevier Scientific 

Publishing Co., 543 p. 
K8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle. 

downgraded scrap. Scrap intended for use in making a 

metal product of lower value than the metal product 

from which the scrap was derived. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

primary metal commodity. Metal commodity produced or 

coproduced from metallic ore. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

secondary metal commodity. Metal commodity derived 

from or contained in scrap. 
U.S. Department of the Interior

U.S. Geological Survey

Molybdenum Recycling in the United States in 1998 

By John W. Blossom 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–L

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 
III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Distribution of Molybdenum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Geologic Occurrence of Molybdenum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Types of Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Sources of Molybdenum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Old Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Disposition of Molybdenum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Recycling Efficiency for Old Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Infrastructure of the Molybdenum Scrap Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Processing of Molybdenum Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Summary and Outlook for Molybdenum Recycling Flow . . . . . . . . . . . . . . . . . . . . . . . 6

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

FIGURES 

1. 	Diagram showing U.S. molybdenum materials flow in 1998 . . . . . . . . . . . . . . . . . L2

2. 	Graph showing U.S. molybdenum consumption, by end-use sector, from 1978

through 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

TABLE 

1. Salient statistics for U.S. molybdenum scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . .L3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

kilometer (km) 

inch (in.) 

Length 

0.6214 

25.4 

mile 

millimeter 

Volume 

cubic foot (ft3

) 0.02832 cubic meter 

Mass 

gram (g) 

kilogram (kg) 

kilogram (kg) 

metric ton (t, 1,000 kg) 

troy ounce (troy oz) 

0.03527 

2.205 

32.1507 

1.102 

31.10 

ounce avoirdupois 

pound avoirdupois 

troy ounce 

short ton (2,000 pounds) 

gram 

Pressure 

pound force per square inch 

atmosphere (atm) 

6.895 

101.3 

kilopascal 

kilopascal 

For temperature conversions from degrees Celsius (°C) to degrees Fahrenheit (°F), use the following: 

°F = (1.8 × °C) + 32 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Molybdenum Recycling in the United States in 1998 

By John W. Blossom 

ABSTRACT 

This report describes the flow of molybdenum in the 

United States in 1998 with emphasis on the extent to which 

molybdenum was recycled. Molybdenum was mostly recycled from products of molybdenum-bearing steels and 

superalloys; some molybdenum products were recovered 

specifically for their high molybdenum content. In 1998, 

8,000 metric tons of molybdenum were estimated to have 

been recycled, and the recycling rate was calculated to be 33 

percent with a recycling efficiency of about 30 percent. 

INTRODUCTION 

The materials flow of molybdenum, as shown in figure 

1, describes molybdenum supply and demand factors for 

the United States in 1998; the figure shows the extent of 

molybdenum recycling1 and aids in identifying recycling 

trends. Knowledge of recycling trends is increasingly 

important because use of scrap promotes conservation of 

natural resources and enhances the sustainability of primary production for a cleaner environment. Definitions of 

specialized terms used in characterizing recycling of metals are given in the appendix. Most data used in this report 

are derived from U.S. Bureau of Mines and U.S. Geological Survey Minerals Yearbooks. Other estimates, such as 

that for old and new scrap generated, are based on these 

data. Some figures, such as unrecovered old scrap, are 

remainders. 

Molybdenum is a refractory metallic element used principally as an alloying agent in cast irons, steels, and superalloys to enhance hardenability, strength, toughness, and 

wear and corrosion resistance. Primarily added in the form 

of ferromolybdenum or molybdic oxide, it is frequently 

used in combination with chromium, columbium (niobium), 

manganese, nickel, tungsten, or other alloy metals to 

achieve desired metallurgical properties. The versatility of 

molybdenum has assured it a significant role in contemporary technology and industry, which increasingly require 

materials that are serviceable under ever higher stresses, 

over greater temperature ranges, and in more-corrosive 

environments. Not only does molybdenum find significant 

1Definitions for selected words are found in the Appendix. 

usage as a refractory metal, but also in numerous chemical 

applications, which include catalysts, lubricants, and pigments. The variety of uses for molybdenum materials, few 

of which afford acceptable substitutions, has resulted in a 

demand that is expected to grow at a greater rate than most 

other ferrous metals. Figure 1 shows the domestic flow of 

molybdenum in 1998 with the flow of recycled molybdenum 

shown in detail. 

DISTRIBUTION OF MOLYBDENUM 

Almost all molybdenum is recovered from low-grade 

deposits that contain the mineral molybdenite (MoS2

). 

Deposits mined primarily for molybdenum provide from 65 

to 70 percent of U.S. output and about 45 percent of world 

output; the remainder is obtained mainly as a byproduct 

from mining large, low-grade porphyry copper deposits. 

Molybdenum ores generally grade from 0.2 to 0.5 weight 

percent molybdenite; copper ores from which byproduct 

molybdenum is recovered contain from 0.02 to 0.08 weight 

percent molybdenite. 

Distribution of molybdenum reserves and productive 

capacity is concentrated in a few countries of the world. In 

1998, world mine output was an estimated 135,000 metric 

tons (t) (molybdenum contained in concentrate), of which 

the United States, China, and Chile provided 80 percent; an 

estimated 10 percent of world output came from Canada and 

Mexico. These same five countries possess about 85 percent 

of the estimated 12 million metric tons (Mt) of molybdenum 

in the world reserve base. The reserve base for the top four 

countries, by contained molybdenum, is United States, 

5,400,000 t; Chile, 2,500,000 t; China, 1,000,000 t; and 

Canada, 910,000 t. Mexico estimates its reserve base to be 

230,000 t. These five countries are expected to continue to 

be the principal mine producers in the 21st century. 

Although exploration for new sources is likely to be successful in other areas, these five countries probably have 

the greatest potential for future additions to reserves and, 

ultimately, to mine output (Blossom, 2001). 

As a result of the concentration of production capacity, 

international trade in molybdenum materials consists primarily of exports from the United States, China, and Chile to 

industrialized nations that lack mine production. The major 

importers are the countries of Western Europe and Japan. 

L1 
L2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

U.S. molybdenum Figure 1. materials flow in 1998. Values are in metric tons contained molybdenum. 
MOLYBDENUM RECYCLING IN THE UNITED STATES IN 1998 

Table 1. Salient statistics for U.S. molybdenum scrap in 1998. 

[Values in metric tons of contained molybdenum, unless otherwise specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 26,700 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,000 

Consumption value3 . . . . . . . . . . . . . . . . . $70 million 

Recycling efficiency4 . . . . . . . . . . . . . . . . . 30 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26,800 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . 18,700 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . . . 4000 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . 33:67 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . 33 percent 

U.S. net imports of scrap10 . . . . . . . . . . . . . . . . . . . . . 190 

Value of U.S. net imports of scrap . . . . . . . . . $1.8 million

1Molybdenum content of products theoretically becoming obsolete in 

the United States in 1998. It excludes dissipative uses. 

2Molybdenum content of products which were recycled in 1998. 

3Unit value of contained molybdenum in molybdenum oxide was used 

in calculating total value of contained metal in scrap. 

4(Old scrap consumed plus old scrap exported) divided by (old scrap 

generated plus old scrap imported plus any old scrap stock decrease or 

minus any old scrap stock increase). 

5Old scrap generated plus old scrap imported plus old scrap stock 

decrease. 

6Old scrap supply minus old scrap consumed minus old scrap exported minus old scrap stock increase. 

7Including prompt industrial scrap but excluding home scrap. 

8Ratio of quantities consumed, expressed as a percentage ratio. 

9Fraction of the molybdenum supply that is scrap on an annual basis. 

It is defined as consumption of old plus consumption of new scrap divided 

by apparent supply (see appendix); measured in weight and expressed as a 

percentage. 

10Trade in scrap is judged to be about equally divided between old and 

new scrap. Net exports are exports of scrap minus imports of scrap. 

The United States has exported about one-half of its mine 

output in recent years, mostly as concentrate or oxide, and 

currently (1998) supplies about 45 percent of the molybdenum consumed in other market-economy countries. 

Because U.S. producers have a viable molybdenum scheme 

made up of a strong reserve base and mining and marketing 

plans, the United States is expected to continue as a leading 

supplier of molybdenum to the world market (Blossom, 

2002). 

Salient molybdenum scrap statistics are based on the 

molybdenum content of catalyst, steel, and superalloy 

scrap. In 1998, about 26,700 t of molybdenum was contained in molybdenum-bearing old scrap available to be 

recycled. About 8,000 t of molybdenum, which was valued 

at about $70 million, was recycled (table 1). The old scrap 

recycling efficiency was calculated to be about 30 percent, 

and the recycling rate was about 33 percent. Molybdenum 

contained in new scrap consumed was about 4,000 t. 

L3 

GEOLOGIC OCCURRENCE OF MOLYBDENUM 

The average crustal abundance of molybdenum is 1 to 

2 parts per million (ppm). Molybdenum does not occur in 

nature in its free or native state, but is found only chemically combined with other elements. MoS2

, which is a leadgray metallic mineral that characteristically occurs in thin, 

tabular, commonly hexagonal plates and is also disseminated as fine particles, is the only molybdenum mineral of 

commercial importance. It has a specific gravity of 4.6 to 

4.7, a hardness of 1 to 1.5, and a greasy feel and soils the 

fingers. Superficially, it resembles graphite, for which it has 

commonly been mistaken (Blossom, 1985; King and others, 

1973). 

Wulfenite (PbMoO3

), which is a molybdate of lead, is a 

metallic mineral of variable color. The mineral has a 

resinous or adamantine luster, a hardness of 2.75 to 3, a specific gravity of 6.5 to 7, and a white streak. It generally 

occurs in well-formed crystals, chiefly square and tabular. 

Deposits are found almost entirely in veins, mostly in the 

oxidized parts of lead deposits. Occurrences of wulfenite 

are numerous, but none are of economic importance. Powellite-scheelite [Ca (Mo, W) O4

] is a calcium molybdatetungsten solid solution series; tungsten may substitute for 

up to 10 percent molybdenum. Primarily hydrothermal, 

powellite and scheelite occur in veins and skarns and are not 

alteration products of molybdenite. Powellite-scheelite is 

nearly always impure; it has a hardness of 3.5 and a specific gravity of 4.3 and varies in color from dirty white to gray, 

straw yellow, greenish yellow, pale greenish blue, and 

brown. Powellite is found with scheelite, and this association helps identify the mineral because it fluoresces a golden yellow. Ferrimolybdite (Fe2

Mo O •8H2O) is a very soft, 3 12

hydrous mineral of distinctive canary-yellow color; it is an 

oxidation product of molybdenite and pyrite. It occurs as 

fine, needlelike crystals and has a hardness of 1.5 and a specific gravity of 2.99 to 4.5. Other molybdenum minerals 

include chillagite, eosite, ilsemannite, jordisite, koechlinite, 

and lindgrenite (King and others, 1973). 

TYPES OF DEPOSITS 

Molybdenum deposits are of five geologic types—porphyry or disseminated deposits, which include stockworks 

and breccia pipes in which metallic sulfides are dispersed 

through relatively large volumes of hydrothermally altered 

and fractured rock; contact-metamorphic zones and tactite 

bodies of silicated carbonate-bearing rocks, such as aplite 

dikes and pegmatites; bedded deposits in sedimentary rocks; 

carbonate-bearing shale, dolostone, and limestone, adjacent 

to intrusive granitic rocks; and quartz veins. 

The first three genetic-type deposits are hydrothermal 

in origin and represent nearly all the identified molybdenum resources currently mined in the world. In hydrothermal deposits, metallic minerals are precipitated from high­
L4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 2. U.S. molybdenum consumption, by end-use sector, from 1978 through 1998. 

temperature aqueous fluids either by changes in temperature and pressure or by evaporation of the liquid. Minerals 

are deposited in the cavities, cracks, or interstices of the 

host rock. Intrusive rocks, with which the metallic minerals 

are genetically related, range from intermediate to felsic in 

composition and include: porphyritic intrusions, dioritic, 

granitic, and quartz monzonitic composition (Bookstrom, 

1999). Metallization commonly takes place in the host 

intrusive and in the surrounding or overlying country rock. 

The Climax and the Henderson deposits in Colorado and 

the Questa deposit in New Mexico are examples of such 

hydrothermal molybdenum stockwork deposits. 

Most of the porphyry copper deposits in the Western 

United States contain small quantities of molybdenite disseminated with the copper minerals through large bodies of 

granite rock. The chief minerals are chalcopyrite and chalcocite; pyrite and small amounts of other sulfides, which 

include molybdenite, also are in the composition. In addition, minor amounts of other base-metal minerals, specular 

hematite, fluorite, and secondary silicate minerals are present. Chalcocite replaces chalcopyrite and pyrite in the zone 

of secondary enrichment. The copper-to-molybdenum ratio 

ranges from about 10 to 1 to perhaps 150 to 1, and generally increases inward and downward within the porphyry 

copper system. 

Small quantities of molybdenite are widely distributed 

in lime-silicate deposits along the contacts between granitic 

intrusive rocks and lime-rich sedimentary rocks. Molybdenite is commonly associated with bismuthinite, copper sulfides, or scheelite in zones of silicated limestone near 

granitic intrusive rocks. The only domestic production from 

this type of mineralization has been as a byproduct from the 

Pine Creek tungsten deposit in California. The mineral 

deposit originated by replacement of the carbonate rock. 

Magmatic hydrothermal fluid also is involved in formation of aplites and pegmatites. Aplites form by “pressure quenching” of magma in response to rapid loss of 

agueous fluid. In pegmatites, crystals and fluid coexist. 

Growth of large crystals is prompted by slow crystal nucleation and rapid ionic diffusion to crystal growth sites. In 

aplites and pegmatites, MoS2 deposition involves interactions among crystals, magma, and magmatic-hydrothermal 

fluid. Pegmatites are coarsely crystalline and consist 

almost exclusively of quartz and feldspar. Molybdenite 

occurs as an accessory mineral, and the individual crystals 

are generally large and usually euhedral. Many pegmatites 

contain apatite, beryl, cassiterite, columbite, ilmenite, 

magnetite, rutile, wolfram, and zircon. The average grade 

of these types of deposits is low; hence, they are not important potential producers of molybdenum. Pegmatite-type 

deposits that contain disseminated molybdenum associated 

with bismuth were mined in Val d’ Or and Preissac in 

Quebec, Canada (King and others, 1973). 

Molybdenum minerals occur in coal, phosphorite, 

shale, lignitic sandstone, and some arkosic sandstone. A 

small quantity of molybdenum was recovered from uraniferous lignites in North Dakota and South Dakota until 1968 

when output from these sources ceased. 

Molybdenum is obtained from primary molybdenum 

mines and byproduct copper and tungsten mines. Countries 

that produced molybdenum in 1998 were Armenia, Canada, 

Chile, China, Iran, Kazakhstan, Mexico, Mongolia, Peru, 

the Republic of Korea, Russia, the United States, and 

Uzbekistan (Blossom, 2001). 
MOLYBDENUM RECYCLING IN THE UNITED STATES IN 1998 L5 

SOURCES OF MOLYBDENUM FROM 

SCRAP 

Molybdenum is recycled as a component of ferrous 

scrap, which comprises home, new, and old scrap. Home, or 

mill scrap is generated within the steel mill during production of iron and steel. Old scrap includes metal articles that 

have been discarded after serving a useful purpose. Because 

of the wide variety of chemical and physical characteristics, 

old scrap often requires significant preparation. The molybdenum component is identified, but in most cases, the scrap 

is selected for other elements that it contains. If additional 

molybdenum is required in the melt in making steel, then 

primary ferromolybdenum or molybdenum oxide, which 

are products derived from ore, are added. 

When the valuable metals or compounds have been 

recovered, molybdenum catalysts are changed to an environmentally acceptable state so that catalysts do not become 

solid waste. These metals may be used again in other end 

uses or reused in catalysts. 

Pure and alloyed molybdenum metal and compound 

scrap from chemical plants, furnaces, trimmings from fabrication processes, and unuseable fabricated items compose 

new scrap and reenter the flow and through the melt 

process. 

Alloy and stainless steel are major sources of molybdenum-bearing scrap. Although molybdenum is not recovered 

separately from scrap steel and superalloys that contain it, 

recycling of these alloys is significant, and the molybdenum 

content is reused. Some of the molybdenum content that is 

recycled, however, may be effectively downgraded in alloys 

where it is tolerated, but not essential. 

OLD SCRAP GENERATED 

As shown in figure 1, the starting point for molybdenum scrap flow through processing is old scrap generated, 

which is the amount of molybdenum that became obsolete 

in 1998. The old scrap supply available to industry is estimated to be 26,700 t; the estimate was based on the lifetimes of products in which molybdenum is used, which 

ranged from 10 to 60 years, with an estimated average of 20 

years. Some scrap is lost to the environment, and some is 

unrecoverable. In 1998, industry used an estimated 8,000 t 

of old scrap; 100 t was exported, and 18,700 t was unrecovered. Figure 2 shows changes in end-use patterns from 1978 

to 1998; these changes will result in changes in the mix of 

end uses of old scrap generated in the future. 

NEW SCRAP 

New scrap consumed in 1998 was estimated to range 

from 3,800 to 4,000 t, of which 200 t was imported and the 

rest, domestically generated. The new-scrap-to-old-scrapconsumption ratio during 1998 was 33 to 67. New scrap 

consisted mainly of trimmings from fabrication processes, 

such as stamping and recycling of unuseable fabricated 

items. New scrap may also be produced in the manufacture 

of another commodity product, such as the tungsten filament used in light bulbs. In its manufacture, the filament is 

twisted around a tiny molybdenum rod. The rod is then 

dissolved in acid and shipped for recycling as a sludge. 

DISPOSITION OF MOLYBDENUM SCRAP 

Old scrap consists mainly of molybdenum-bearing 

steel, which includes alloy, carbon, and stainless steel, that 

may have been used in many applications. The steel grades 

with the highest percentages of molybdenum are in the alloy 

and stainless steel categories. The highest volume of production, however, is in carbon steel. This scrap, which is 

derived from demolition of bridges, buildings, and other 

structures, junked cars, and manufacturing equipment, is 

sold to scrap dealers. Molybdenum catalysts, sometimes in 

relatively pure form and sometimes contained in sludges, 

usually are sold by chemical processors to small specialized 

catalyst-recycling plants. 

RECYCLING EFFICIENCY 

FOR OLD SCRAP 

The relation between the amount of scrap that is theoretically available for recycling and what is actually recovered and reused is called recycling efficiency. Old scrap 

recycling efficiency during 1998 was estimated to be 30 percent. Because data were not available, stock changes were 

not taken into account. Recycling efficiency is not expected 

to increase significantly because molybdenum scrap competes with new materials, which are readily available and 

tend to suppress some molybdenum-bearing scrap prices, 

thereby limiting scrap recycling and, consequently, recycling efficiency. Additionally, much molybdenum-bearing 

scrap, such as stainless steel scrap, is usually purchased for 

other metal content, so its collection usually is dependent on 

the prices of other commodities, such as chromium and 

nickel. 

INFRASTRUCTURE OF THE 

MOLYBDENUM SCRAP INDUSTRY 

Steel mills and foundries that require ferrous molybdenum-bearing scrap and superalloy melt shops that 

require pure molybdenum scrap are supplied by brokers 

and scrap collectors and processors (Fenton, 2001). Other 

types of scrap from spent catalyst and metal-laden solutions, such as those generated in the production of light 

bulb filaments, must be processed to comply with environmental requirements. Brokers bring scrap buyers and sellers together on a scrap transaction and receive a fee for this 

service. Consumers use brokers to procure scrap; processors use their services to market their scrap. Brokers purchase scrap for a particular client buyer without having 

storage or processing facilities or sometimes without any 
L6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

certainty of finding a buyer who will offer a favorable price 

and profit. The scrap recycling infrastructure in the United 

States causes its recycling rate to be equal to and, in most 

cases, exceed that of other industrialized countries, and the 

rate is much higher than that of lesser developed countries. 

Amlon Metals Inc., which was headquartered in New 

York, N.Y., and was founded about 1950, provided reclamation services worldwide. The company recycled about 

200,000 t per year of metal-bearing materials and provided 

documents, sampling, transport, and certification of recycling materials. Their focus was on about 10 metals, which 

included molybdenum, and catalysts where a significant 

portion of their business. Hi-Temp Specialty Metals in Willingboro, N.J., processed chips, electrodes, molybdenum 

turnings, and wire. International Metals Reclamation Company, Inc. (INMETCO) in Ellwood City, Pa., converted 

about 63,000 t of molybdenum-bearing secondary material, 

which included electric-arc furnace (EAF) dust, spent catalyst, mill scale, and grinding swarf, into about 24,000 t of 

iron-chromium-nickel ingots with 1.1 percent molybdenum 

content. The molybdenum recycled from this source alone 

was about 264 t (Cassidy, 2001). 

PM Recovery in New Castle, Pa., specialized in processing molybdenum-bearing nickel and cobalt-based 

grindings, turnings, and off-specification ingot. Kalumetals, 

Inc. in Latrobe, Pa., used a batch-process furnace to produce 

molybdenum oxide. Langeloth Metallurgical in Pittsburgh, 

Pa., used some secondary material in its molybdenum oxide 

roasters (Cassidy, 2001). 

PROCESSING OF MOLYBDENUM SCRAP 

By using a variety of equipment, scrap dealers collect 

and process scrap into a physical form and chemical composition that can be consumed. The type and size of equipment they use depends on the types and volume of scrap 

available in the area and the requirements of their customers. The largest and most expensive piece of equipment 

is the shredder. The shredder can fragment discarded objects 

into fist-sized pieces; shredded metals, glass, rubber, and 

plastic are segregated before shipment. Hydraulic shears, 

which have cutting blades of chromium-nickel-molybdenum alloy steel for hardness, slice heavy pieces of plate, 

chemical piping, and structural steel into chargeable pieces. 

Baling presses are used to compact scrap into manageable 

bundles, thereby reducing scrap volume and shipping costs. 

Scrap dealers must carefully sort the scrap they sell, and 

consumers must purchase scrap that does not contain unacceptable levels of undesirable elements. 

Old and new molybdenum scrap consumed or recycled 

during 1998 was about 12,000 t (4,000 t new and 8,000 t 

old). Appliances, bicycles, and other molybdenum-bearing 

steel were shredded for recycling. More than 1,500 scrap 

yards processed steel from construction and demolition sites 

by shearing, shredding, and baling. 

Fabrication of new products produces new scrap that is 

relatively chemically and physically clean and of known 

chemical composition. For this reason, most scrap consumers prefer new scrap to old scrap. Preparation of new 

scrap is usually limited to cutting, cleaning, and baling prior 

to rapid transport back to the consumer for recycling. 

Processes used may include calcining, drying, leaching, 

precipitation, and various means of separation. Some processing may be subcontracted for sludgelike material, catalysts, dusts, grindings, and solutions. Hi-Temp Specialty 

Metals processed chips, electrodes, molybdenum turnings, 

and wire by crushing and abrading the material in a ring mill 

to remove oxide films in preparation for vacuum melting by 

others. A roasting process was used by INMETCO and Langeloth Metallurgical at their Ellwood City and Pittsburgh, 

Pa., facilities (Cassidy, 2001). 

SUMMARY AND OUTLOOK FOR 

MOLYBDENUM RECYCLING FLOW 

Consumption of molybdenum, and the growth or 

decline of the scrap industry, depends directly on the health 

of the specialty and carbon steelmaking industries. Most 

regions of the world will see a marked increase in steel consumption during the next 5 years, according to the International Iron and Steel Institute (American Metal Market, 

2000). In the United States, a steadily increasing population 

and a growing economy in the long term should assure that 

the demand for steel products, and the scrap used to make 

them, will also increase. Steel and scrap consumption will 

increase as Federal funding of highway and bridge projects 

increases and will require structural and reinforcement bar 

products. The use of steel framing is increasing in construction of multifamily developments, retirement homes, and 

single-family residences. A thriving industry is also dependent on plentiful inexpensive energy. As energy costs rise, the 

demand for some steel applications may be affected, but 

demand for pipe and tubular goods used in the oil and gas 

industry will increase for new drilling and refining projects 

(Fenton, 2001). 

The EAF consumes mostly scrap to make steel. The 

EAF contribution to total steel production has risen dramatically during the past 30 years, and the amount of EAFproduced steel should continue to increase, perhaps at a 

rate of 4 percent per year during the next decade (Steel 

Times International, 2000). The EAF may be the primary 

steel production method in the world by 2010 (Forster, 

1999). The use of the EAF has increased in minimills from 

small units limited in use for specialty steel production to 

the large-capacity furnace used to produce a wide range of 

steels, which includes flat product sheet and plate, long 

product bars, structural shapes, tubulars, and wire (Recycling Today, 1998). From 1998 through 2000, EAF steel 

comprised nearly 50 percent of all steel produced in the 

United States (Fenton, 2002). 
MOLYBDENUM RECYCLING IN THE UNITED STATES IN 1998 L7 

The availability of scrap, and operating and capital cost 

advantages, have made EAF growth possible. Relocations 

and establishments of new minimills in areas of increasing 

population growth and manufacturing activity in the Southern States and the Western States and away from the traditional “Rust Belt” States have, to a large extent, satisfied 

demand for construction steel products and products used 

by the oil and gas industry. The EAF process is flexible in 

its material requirements, and plants can also operate with 

considerable flexibility in making various products depending on market requirements (Worden, 2000). EAF steelmaking will continue to grow because of the capital and 

operating cost advantages relative to those of the basic-oxygen furnace (BOF), the increasingly wide range of steel 

products that it makes, and its environmental cleanliness. 

The use of the EAF is the most effective way of reducing 

carbon dioxide emissions, and less energy is needed to melt 

scrap than to smelt ore. Use of EAFs will increase as minimills are built, and EAFs may replace more operating 

BOFs (Katrak and others, 1999). 

Ferrous alloy scrap will remain the most important raw 

material used. Increasing availability of direct-reduced and 

hot-briqueted iron from domestic producers because of the 

increasing need for low-residual element feedstocks for the 

production of high-quality flat steel and special-bar-quality 

steels required to compete in the higher end markets will be 

a factor in dampening this trend. 

Recycling of molybdenum-bearing scrap will continue to be dependent on the markets for the principal alloy 

metals of iron, nickel, and chromium, in which molybdenum is often found. Although large quantities of molybdenum will continue to be consumed in downgraded form 

in steelmaking, molybdenum will continue to be recycled 

in this manner. As long as the value of molybdenum 

remains relatively low, scrap metal is not likely to be 

sought for its molybdenum content. Therefore, recycling 

rates and efficiency are not likely to change significantly 

in the near term. 
L8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

REFERENCES CITED


American Metal Market, 2000, IISI sees consumption up 

2% to 830M tons by 2005: American Metal Market, 

v. 108, no. 193, October 5, p. 1. 

Blossom, J.W., 1985, Molybdenum, in Mineral facts and 

problems: U.S. Bureau of Mines Bulletin 675, p. 

521–534. 

Blossom, J.W., 2001, Molybdenum: U.S. Geological Survey Mineral Commodity Summaries 2001, p. 110–111. 

Blossom, J.W., 2002, Molybdenum, in Metals and minerals: 

U.S. Geological Survey Minerals Yearbook 2000, v. I, 

p. 53.1–53.10.

Bookstrom, A.A., 1999, Molybdenum, in Marshall, C.P., 

and Fairbridge, R.W., Encyclopedia of geochemistry: 

Boston, Kluwer Academic Publishers, p. 411–413. 

Cassidy, D.J., 2001, U.S. plants operated solely to recycle 

metal-rich wastes: Recycling Metals from Industrial 

Waste—Three Day Short Course and Workshop with 

Emphasis on Plant Practice, Golden, Colo., June 19-21, 

2001, Presentation, unpaginated. 

Fenton, M.D., 2001, Iron and steel recycling in the United 

States: U.S. Geological Survey Open-File Report 

01–224, July, 9 p. 

Fenton, M.D., 2002, Iron and steel, in Metals and minerals: 

U.S. Geological Survey Minerals Yearbook 2000, v. I, 

p. 40.1–40.14.

Forster, Harriet, 1999, Global growth seen for EAF into millennium: American Metal Market Electric Furnace 

Supplement, February 4, p. 17A. 

Katrak, F.E., Agarwal, J.C., and Persampieri, David, 1999, 

Global restructuring of the steel industry: American 

Metal Market Steel Forecast Supplement, January 5, 

p. 15A.

King, R.U., Shawe, D.R., and Mackevett, E.M., Jr., 1973, 

Molybdenum, in Brobst, D.A., and Pratt, W.P., eds., 

United States mineral resources: U.S. Geological 

Survey Professional Paper 820, p. 425–435. 

Recycling Today, 1998, Potential scrap shortage no hindrance to steel industry: Recycling Today, v. 36, no. 1, 

January, p. 14. 

Steel Times International, 2000, Technical challenges of 

EAF steelmaking in 2010: Steel Times International, 

March, p. 18. 

Worden, Edward, 2000, Ispat scrap needs could rise with 

furnace conversion plan: American Metal Market, 

v. 108, no. 178, September 14, p. 11. 
MOLYBDENUM RECYCLING IN THE UNITED STATES IN 1998 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle. 

downgraded scrap. Scrap intended for use in making a 

metal product of lower value than the metal product 

from which the scrap was derived. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed in percent of new plus old scrap consumed 

(for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Metal content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

L9 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as (consumption of old 

scrap (COS) plus exports of old scrap (OSE)) divided 

by (old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks), measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

primary metal commodity. Metal commodity produced or 

coproduced from metallic ore. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as (consumption of old scrap (COS) plus consumption of new 

scrap (CNS)) divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

secondary metal commodity. Metal commodity derived 

from or contained in scrap. 
U.S. Department of the Interior

U.S. Geological Survey

Cobalt Recycling in the United States in 1998 

By Kim B. Shedd 

U.S. GEOLOGICAL SURVEY CIRCULAR 1196–M

FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES

III 

FOREWORD


As world population increases and the world economy expands, so does the demand 

for natural resources. An accurate assessment of the Nation’s mineral resources must 

include not only the resources available in the ground but also those that become available 

through recycling. Supplying this information to decisionmakers is an essential part of the 

USGS commitment to providing the science that society needs to meet natural resource 

and environmental challenges. 

The U.S. Geological Survey is authorized by Congress to collect, analyze, and 

disseminate data on the domestic and international supply of and demand for minerals 

essential to the U.S. economy and national security. This information on mineral 

occurrence, production, use, and recycling helps policymakers manage resources 

wisely. 

USGS Circular 1196, “Flow Studies for Recycling Metal Commodities in the 

United States,” presents the results of flow studies for recycling 26 metal commodities, 

from aluminum to zinc. These metals are a key component of the U.S. economy. 

Overall, recycling accounts for more than half of the U.S. metal supply by weight 

and roughly 40 percent by value. 

Charles G. Groat 

Director 
IV 

CONTENTS


Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III


Conversion Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Global Geologic Occurrence of Cobalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Cobalt Production Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3


Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


Sources of Cobalt Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Old Scrap Generated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


New Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6


Scrap Imports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7


Disposition of Cobalt Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Scrap Consumption (Recycling and Recovery) . . . . . . . . . . . . . . . . . . . . . . . . 7


Scrap Exports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7


Unrecovered Old Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8


Old Scrap Recycling Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Infrastructure of the Cobalt Scrap Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8


Alloy Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8


Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9


Processing of Cobalt Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9


Alloy Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


Battery Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


Cemented Carbide Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


Diamond Tool Scrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


Mixed Scrap Feeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10


Spent Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11


Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Appendix—Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

FIGURES 

1. 	Flow diagram showing U.S. cobalt materials flow in 1998. . . . . . . . . . . . . . . . . . . . . . . M2 

2. 	Graph showing U.S. cobalt consumption in superalloys from 1978 through 1998. . . . . 4


3. 	Graph showing U.S. cobalt consumption, by end-use sector, excluding 


superalloys, from 1978 through 1998.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4. 	Graph showing U.S. spot cobalt cathode prices from 1988 through 1998. . . . . . . . . 6

TABLE 

1. Salient statistics for U.S. cobalt scrap in 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . .M3
CONTENTS V 

CONVERSION FACTORS 

Multiply By To obtain 

metric ton (t, 1,000 kg) 1.102 short ton (2,000 pounds) 

million metric tons (Mt) 1,102,000 short ton 
FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Cobalt Recycling in the United States in 1998 

By Kim B. Shedd 

ABSTRACT 

This report, which is one of a series of reports on metals 

recycling, defines and quantifies the 1998 flow of cobaltbearing materials in the United States from imports and stock 

releases through consumption and disposition with particular 

emphasis on the recycling of industrial scrap (new scrap) and 

used products (old scrap). Because of cobalt's many diverse 

uses, numerous types of scrap were available for recycling by 

a wide variety of processes. In 1998, an estimated 32 percent 

of U.S. cobalt supply was derived from scrap. The ratio of 

cobalt consumed from new scrap to that from old scrap was 

estimated to be 50:50. Of all the cobalt in old scrap available 

for recycling, an estimated 68 percent was either consumed 

in the United States or exported to be recycled. 

INTRODUCTION 

The purpose of this report is to define and quantify the 

recycling1 of cobalt-bearing scrap, which represents an 

important component of total cobalt supply. Figure 1 illustrates the flow of cobalt in 1998. It shows sources and distribution of U.S. cobalt supply with particular emphasis on 

the flow of cobalt-bearing scrap. Table 1 lists salient cobalt 

scrap statistics for 1998. 

Cobalt is a silvery gray metal with many diverse uses 

that result from several of its unique properties—it has a high 

melting point, is ferromagnetic and retains its ferromagnetism at the highest temperature of any metal, is multivalent, 

and produces intense blue colors in conjunction with silica. 

GLOBAL GEOLOGIC OCCURRENCE OF COBALT 

The average concentration of cobalt in the Earth’s crust 

is estimated to be approximately 0.002 percent. It is present 

in a large number of distinct mineral species, which include 

arsenides, hydrates, oxides, sulfarsenides, and sulfides. 

Most economically important terrestrial cobalt-bearing ore 

deposits can be classified as one of the following types: 

hydrothermal, lateritic nickel, magmatic nickel, or sedimenthosted (stratiform) copper. In addition to terrestrial deposits, 

large resources of cobalt are present in metal-rich nodules 

1Definitions for selected words are found in the Appendix. 

and crusts on the ocean floor (Young, 1960, p. 12–15; Vhay 

and others, 1973, p. 145–150; Crockett and others, 1987, 

p. 6–7; and Alcock, 1988, p. 70–73, 78–81, 84–85). 

Hydrothermal deposits form when cobalt minerals are 

precipitated from hot aqueous solutions into fractures or 

other openings or in place of preexisting minerals. Cobalt 

arsenides and sulfarsenides, such as cobaltite, skutterudite, 

and smaltite, are characteristic minerals of hydrothermal 

cobalt deposits (Young, 1960, p. 14, 16–17, 18, 22, 24; Vhay 

and others, 1973, p. 149–150; and Crockett and others, 

1987, p. 7). 

Laterites are soils formed over large areas of low relief 

by atmospheric weathering of sulfide and silicate ore minerals usually in hot and humid subtropical to tropical climates. 

Compared with the original unweathered rock, lateritic soils 

formed from ultramafic igneous rocks and their serpentinized derivatives are enriched in iron, nickel, cobalt, and 

other minor constituents. The nickel and cobalt minerals 

formed by this weathering include various complex carbonates, oxides, and hydroxides. Absolite, which is a mixture of 

cobalt and manganese oxides, is one example (Young, 1960, 

p. 14–16, 18, 25; Vhay and others, 1973, p. 148; Crockett 

and others, 1987, p. 7; Alcock, 1988, p. 78–81; and Burger, 

1995, p. 1, 12, 14). 

Magmatic ore deposits are formed when an immiscible 

sulfide liquid separates from and concentrates within a 

cooling and crystallizing mass of molten rock. This can 

occur above ground in lava flows or underground in intrusions of molten rock. In magmatic ore deposits, cobalt is 

concentrated along with nickel and iron in such sulfide minerals as pentlandite and pyrrhotite (Young, 1960, p. 12–16; 

Vhay and others, 1973, p. 146–147; Crockett and others, 

1987, p. 6–7; and Alcock, 1988, p. 70–73). 

Sediment-hosted copper deposits are also called 

stratabound or stratiform deposits. These deposits are copper-rich layers in sedimentary rocks. Some sediment-hosted 

copper deposits have been upgraded by supergene (weathering) processes. The cobalt-bearing minerals in unweathered 

rocks of these deposits include such sulfides as linnaeite and 

carrolite; oxides, such as heterogenite, are present in the 

weathered rocks (Young, 1960, p. 15–19, 21–22; Vhay and 

others, 1973, p. 150; and Crockett and others, 1987, p. 7). 

M1 
M2 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 1. U.S. cobalt materials flow in 1998. Values are in metric tons of contained cobalt, are rounded to no more than threesignificant digits, and may not add to totals shown. NA, not available: W, withheld to avoid disclosing company proprietary data. 
COBALT RECYCLING IN THE UNITED STATES IN 1998 

Table 1. Salient statistics for U.S. cobalt scrap in 1998. 

[Values in metric tons of contained cobalt, unless otherwise 

specified] 

Old scrap: 

Generated1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,500 

Consumed2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,700 

Consumption value3 . . . . . . . . . . . . . . . . . $40 million 

Recycling efficiency4 . . . . . . . . . . . . . . . . . 68 percent 

Supply5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,830 

Unrecovered6 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,230 

New scrap consumed7 . . . . . . . . . . . . . . . . . . . . . . . 1,700 

New-to-old-scrap ratio8 . . . . . . . . . . . . . . . . . . . . . . 50:50 

Recycling rate9 . . . . . . . . . . . . . . . . . . . . . . . . . 32 percent 

U.S. net exports of scrap10 . . . . . . . . . . . . . . . . . . . . 1,200 

Value of U.S. net exports of scrap11 . . . . . . . . . $40 million 

1Old scrap generated is estimated to have been the cobalt content of 

products theoretically becoming obsolete in the United States in 1998. 

2Old scrap consumed is estimated to have been the cobalt content of 

used products that were recycled in 1998. 

3Value of cobalt contained in old scrap, which was based on estimated quantities and values of the various types of cobalt scrap consumed. 

4Recycling efficiency is (old scrap consumed plus old scrap exported) 

divided by (old scrap generated plus old scrap imported plus any old scrap 

stock decrease or minus any old scrap stock increase). 

5Old scrap supply is old scrap generated plus old scrap imported plus 

old scrap stock decrease. 

6Old scrap unrecovered is old scrap supply minus old scrap consumed 

minus old scrap exported minus old scrap stock increase. 

7New scrap consumption includes prompt industrial scrap but 

excludes home scrap. 

8New-to-old-scrap ratio is the ratio of quantities consumed, expressed 

as a percentage. 

9Recycling rate is the fraction of the apparent cobalt supply that is 

scrap, on an annual basis. It is defined as (consumption of old plus consumption of new scrap) divided by apparent supply (see Appendix); measured in weight and expressed as a percentage. 

10Net exports of scrap are cobalt contained in exports minus cobalt 

contained in imports of scrap. Trade in cobalt-bearing scrap is assumed to 

be 50 percent new scrap and 50 percent old scrap. 11Estimated unit value for net exports is greater than that for old scrap 

consumed because of the mix of scrap types assumed to be exported, 

imported, and consumed. 

In 1998, the United States produced only negligible 

amounts of byproduct cobalt from its mining operations and 

had no production where cobalt was the primary commodity. The principal countries where cobalt was mined were 

Australia, Canada, Cuba, the Democratic Republic of the 

Congo [Congo (Kinshasa)], New Caledonia, Russia, and 

Zambia (Shedd, 2001, p. 20.17). Cobalt mined in Congo 

(Kinshasa) and Zambia was as a byproduct of copper from 

sediment-hosted deposits. Cobalt mine production from 

most other countries was as a byproduct of nickel. Cuban 

and New Caledonian production was from lateritic deposits. 

Canadian and most of the Russian production was from sulfide deposits. Production from Australia was from lateritic 

M3 

and sulfide deposits. Only in Morocco was cobalt produced 

as the primary commodity from a mining operation; the 

deposits in Morocco are hydrothermal in origin. 

COBALT PRODUCTION PROCESSES 

Cobalt-bearing ores are mined by conventional underground or open pit methods. They are processed by a wide 

variety of extractive metallurgical techniques depending on 

the type of ore, the availability of energy, environmental 

concerns, market demand for primary products and byproducts, and overall project economics. Nickel laterite ores are 

usually processed directly. Most other cobalt-bearing ores 

are first beneficiated, either by mineral flotation or gravimetric methods, to produce a mineral concentrate (De 

Cuyper, 1988, p. 206). Some ores and concentrates are 

roasted or smelted to a material referred to as “matte” prior 

to refining. Most cobalt-producing refineries use hydrometallurgical methods to extract the desirable metals from the 

ores, concentrates, or mattes and to separate cobalt from the 

other metals present in the resulting solutions (Kerfoot and 

Weir, 1988, p. 256). Some refineries also process scrap and 

cobalt intermediates, such as alloys, impure cobalt compounds, mixed metal sulfides, residues, and slags. Depending on the final processing steps, refined cobalt can be in the 

form of cobalt metal (cathode, granules, or ingot), metal 

powder (loose or briquetted), or cobalt chemicals (acetates, 

carbonate, chlorides, hydroxides, nitrates, oxides, or sulfates). 

USES 

U.S. cobalt consumption in 1998 can be divided into 

the following end-use categories: superalloys (44 percent); 

chemical compounds for a variety of applications (31 percent); cemented carbides and diamond tools (9 percent); 

magnetic alloys (8 percent); and specialty steels, other 

alloys, and other metallic uses (8 percent) (Shedd, 2001, p. 

20.12). Superalloys are alloys developed for high-temperature service where relatively high mechanical stress is 

encountered and where surface stability is frequently 

required. Cobalt-bearing magnetic alloys include permanent magnetic alloys, such as alnico, samarium-cobalt, and 

iron-neodymium-boron, and soft magnetic alloys, such as 

permendur. Cobalt-bearing steels include high-speed steels 

from which cutting tools are made and maraging steels, 

which are characterized by their strength and workability. 

Other cobalt-bearing alloys are characterized by their 

resistance to corrosion and/or wear or by their controlled 

expansion. 

Cemented carbides, which are also referred to as “hardmetals,” are sintered powder metallurgical parts used as cutting tools and wear-resistant components by the metalworking, mining, oil drilling, and construction industries. In 

making these parts, cobalt metal powder is used as a binder 

to hold together the tungsten carbide grains. Diamond tools 

are similar to cemented carbides in that cobalt is used as a 
M4 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

binding agent to hold together wear-resistant particles, 

which, in this case, are diamonds. Saws for cutting nonmetallic materials, such as stone and concrete, are essentially steel wheels with diamond-bonded segments attached to 

their circumference. The segments are made by blending, 

pressing, and sintering a mix of diamonds and cobalt metal 

powder. Diamond polishing wheels for grinding gem-quality diamonds are made by impregnating diamonds into a surface layer of cobalt on a steel wheel (Cobalt Development 

Institute, 1993; 2001, p. 83–84). 

Applications for cobalt chemical compounds include 

animal feed additives, bonding agents in steel-belted radial 

tires, catalysts for the chemical and petroleum industries, 

drying agents for paint, electrodes for rechargeable batteries, glass decolorizers, ground coat frits for porcelain enamels, magnetic recording media, and pigments. Most of these 

applications are considered to be dissipative—the cobalt 

represents an important but very minor constituent of the 

final product, which is widely distributed during use. This 

makes cobalt reclamation or recycling impractical or impossible. Two exceptions are the use of cobalt in catalysts and 

rechargeable batteries, which are products that are recycled. 

Cobalt catalysts are used to improve the reaction rates 

of various processes in the chemical and petroleum industries. In 1998, the top two applications that used cobalt catalysts were the hydroprocessing of petroleum and the production of terephthalic acid (TPA) and dimethyl terephthalate (DMT), which were intermediate compounds in the 

production of polyester (Field, 1999). 

Rechargeable batteries are a relatively new and rapidly 

growing application for cobalt. In 1998, three types of 

rechargeable batteries contained cobalt—lithium-ion (Liion), nickel-cadmium (NiCd), and nickel-metal hydride 

(NiMH). The percentages by weight of cobalt in the electrodes in each of these battery types were as follows: Liion, 0 to 50 percent of the cathode; NiCd, 3 to 10 percent of 

the cathode; and NiMH, 3 to 10 percent of the cathode and 

3 to 15 percent of the anode (Dominey, 1997). These batteries were either large wet industrial batteries or small sealed 

dry-cell consumer batteries. 

In 1998, the United States was the world's largest consumer of cobalt (Burstow, 2000). Compared with total 

world cobalt consumption, the United States consumed proportionally more cobalt to make superalloys but less to 

make batteries (Clark, 1996; Dominey, 1997). Even though 

as much as 70 percent of cobalt-bearing batteries were made 

in Asia, a significant percentage of these batteries would 

have been sent to the United States to be used by U.S. consumers (Dominey, 1997). 

Figures 2 and 3 show trends in U.S. consumption of 

cobalt by various industry sectors since 1978. In figure 2, 

the cyclic nature of commercial aircraft production is shown 

in the pattern of cobalt consumption to make superalloys 

(Schenk, 1998). Figure 3 shows a decrease in cobalt consumption by various industries in the late 1970s to early 

1980s. This change in consumption was the result of efforts 

to conserve cobalt and to find substitutes following a rapid 

price increase in the late 1970s and recession in the early 

Figure 2. U.S. cobalt consumption in superalloys from 1978 through 1998. Values are in metric tons of contained cobalt. 
COBALT RECYCLING IN THE UNITED STATES IN 1998 M5 

Figure 3. U.S. cobalt consumption, by end-use sector, excluding superalloys, from 1978 through 1998. 

Values are in metric tons of contained cobalt. 

1980s (Shedd, 1999). Figure 3 also shows increasing cobalt 

consumption for cemented carbides and chemical applications beginning in 1983. 

In the late 1970s, approximately one-quarter of U.S. 

cobalt consumption was for chemical uses, and three-quarters was for metallurgical uses. By the early 1990s, the 

proportion of U.S. cobalt consumption for chemical uses 

had grown to approximately one-third of total U.S. consumption. Although some chemical uses of cobalt are 

recycled, many are dissipative. As a result, an increase in 

cobalt consumption in chemical uses has the potential to 

decrease the proportion of cobalt consumption available 

for recycling. 

PRICES 

The price of cobalt metal has a significant influence on 

its recycling rate. Higher prices for cobalt encourage recycling and metal recovery; lower prices do not. Since the late 

1970s, free market prices for cobalt have varied considerably (Shedd, 1999). During the 1990s, the U.S. spot price 

for cobalt cathode (minimum of 99.8 percent cobalt), as 

reported in Platt's Metals Week, fluctuated widely between 

a low of $7.50 per pound ($16.50 per kilogram) and a high 

of $35 per pound ($77 per kilogram) (figure 4). Although 

this price varied significantly during the course of each 

year, the annual average price has trended downward since 

1995. During 1998, the U.S. spot cathode price decreased 

to a low of $10 per pound ($22 per kilogram) in midDecember from a high of $26 per pound ($57 per kilogram) 

in early January. 

SOURCES OF COBALT SCRAP 

Sources of cobalt scrap are key features of the U.S. 

cobalt materials flow shown in figure 1. Domestic scrap 

originates during manufacturing and following use of products in the United States. Scrap generated in foreign countries can enter the United States as imports. 

OLD SCRAP GENERATED 

Old scrap consists of cobalt-bearing products that are 

no longer being used. Some examples are used turbine 

blades and other parts removed from jet engines, spent 

rechargeable batteries, spent catalysts, used cemented carbide cutting tools, and magnets removed from consumer or 

industrial equipment. To estimate the amount of cobalt that 

becomes available from old scrap (termed “old scrap generated”) in 1998, the following approach was used. For each 

cobalt-consuming industry in the United States, the average 

number of years the products would be in use was estimated. These product lifetimes were subtracted from 1998 to 

determine the year in which the product would have been 

manufactured. The amount of cobalt in the products was 

based on the amount of cobalt consumed by that industry 

sector during the year of manufacture minus the amount of 

cobalt that ended up as waste materials or new scrap. The 

amount of cobalt consumed by each industry sector in the 

year the products were manufactured was based on information collected by the U.S. Bureau of Mines or the U.S. 

Geological Survey. The percentage of cobalt consumed by 

each sector that ended up in final products was derived from 

the National Research Council (1983). 
M6 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Figure 4. U.S. spot cobalt cathode prices from 1988 through 1998. (Source: Platt’s Metals Week) 

This method of estimating old scrap generated is based 

entirely on cobalt consumed to make products in the United 

States and does not take into account the amount of cobalt 

in products imported into the country or exported out of the 

country. Although the net trade of cobalt in products could 

significantly alter the estimation of old scrap generated, the 

amount of cobalt in imported and exported products would 

be very difficult to quantify. Such items as magnets and 

rechargeable batteries are present in a multitude of products, 

instrumentation, and equipment used by consumers, industry, and the military and come in a multitude of sizes and 

various chemical compositions, some of which contain 

cobalt and some of which do not. Because of the lack of 

adequate information from which to make reliable estimates, no attempt was made to estimate the net trade of 

cobalt in products for this study. 

As shown in figure 1 and table 1, 3,500 metric tons (t) 

of cobalt was contained in products that theoretically 

became available for recycling in 1998. 

NEW SCRAP 

New scrap is generated during the manufacture of 

alloys and other cobalt-bearing materials and products. It is 

often divided into “hard” and “soft” scrap. Hard scrap is in 

the form of solid pieces, such as subspecification alloy or 

cemented carbide parts or excess alloy generated during 

casting operations or removed during pressing and forging 

operations. Soft scrap is finely divided material. Examples 

include grinding sludges, swarf, turnings generated during 

machining of steel and alloy parts, baghouse dust from steel 

and alloy manufacturing, and loose powders generated from 

powder metallurgical processes. 

The superalloy industry typically generates large quantities of new scrap. The buy-to-fly ratio, which is the weight 

of metal purchased versus the weight of the finished parts, 

provides a measure of the amount of scrap generated. 

Depending on the part being made, these ratios can range 

from less than 5 to 1 to greater than 20 to 1. In 1998, the 

average buy-to-fly ratio was about 7 to 1; this means that for 

every kilogram of aircraft engine parts produced, 7 kilograms (kg) of metal was purchased and 6 kg of scrap was 

generated (Lane, 1998; Schenk, 1998). New superalloy 

scrap can be in the form of solids, turnings, or grindings. 

By volume, turnings are the largest quantity generated 

(Lane, 1998). 

New scrap is also generated during the casting of corrosion-resistant alloys. In this industry sector, for every kilogram of alloy poured, only 0.4 to 0.6 kg of usable casting is 

produced. In other words, 40 to 60 percent of the melt 

becomes new scrap, which would be either recycled inhouse or sold to be recycled elsewhere. The number of buyers may be limited, however, by the composition of the 

scrap. Certain elements that may be present in cobalt-base 

corrosion-resistant alloys, such as copper and tungsten, are 

not tolerated in many other cobalt-bearing alloys (Spence 

and Stickle, 2002). 

For the purpose of this study, new scrap does not 

include home scrap, which is generated and consumed 
COBALT RECYCLING IN THE UNITED STATES IN 1998 

within a single plant. Quantities of new scrap and home 

scrap generated by U.S. producers of cobalt metal powder 

and chemicals were estimated from information in the U.S. 

Environmental Protection Agency's Toxics Release Inventory (TRI). Reports that provided data on releases, transfers, 

and recycling of cobalt compounds were generated by using 

the toxic releases query form at URL http://www.epa.gov/ 

enviro/html/tris/tris_query.html. Reported data from individual plants were summed to estimate U.S. totals. In 1998, 

the cobalt metal powder and chemical producers recycled 

approximately 20 t of cobalt in new scrap inhouse (identified as home scrap in figure 1), transferred approximately 

30 t of cobalt in new scrap to other plants to be recycled, 

and released approximately 15 t of cobalt as processing 

losses to the air, land, or water. 

Cobalt in processing losses, new scrap generated, and 

products from U.S. industry sectors that produced alloys, 

parts, and other cobalt-bearing products are shown on the 

right-hand side of figure 1. The amount of cobalt lost during 

fabrication was derived from TRI releases. In 1998, approximately 350 t of cobalt was released as processing losses. 

This equaled 3 percent of the apparent supply of cobalt used 

for fabrication. The amount of cobalt in new scrap generated in 1998 was calculated by adding the estimates for cobalt 

in new scrap consumed and new scrap exports. 

SCRAP IMPORTS 

U.S. trade statistics are classified under the Harmonized Tariff Schedule of the United States Annotated 

(HTSA). The HTSA provides statistical categories and the 

applicable tariff rates for all merchandise imported into the 

United States. It is based on the international Harmonized 

System, which is the global classification system that is 

used to describe most world trade in goods. 

The U.S. Census Bureau reported gross weight and customs value of imports of cobalt waste and scrap under 

HTSA category 8105.10.9000. The cobalt content of these 

imports was estimated as follows: for each month, for each 

country of origin and port of entry, the gross weight was 

multiplied by the unit value divided by Platt’s Metals 

Week’s monthly average spot price for cobalt metal. 

In 1998, the United States imported an estimated 250 t 

of cobalt in cobalt-bearing scrap under HTSA category 

8105.10.9000. On the basis of gross weight, most of this 

scrap originated from Belgium, Canada, Finland, France, 

Germany, Japan, the Netherlands, and the United Kingdom. 

Additional cobalt was likely to have been imported in 

scrap listed under other HTSA categories. One example 

would be superalloy scrap imported under the HTSA category for nickel waste and scrap (7503.00.0000). The total 

estimated cobalt content of imported scrap was increased to 

600 t to include an estimate for the cobalt content of these 

other types of scrap. 

Specific information on the type of scrap imported was 

not available. Industry sources confirmed that much of the 

M7 

imported superalloy scrap is in the form of turnings. The 

amounts of new and old scrap imported were estimated by 

using the new-scrap-to-old-scrap ratio of 50:50 that was calculated for U.S. consumption. 

DISPOSITION OF COBALT SCRAP 

Cobalt-bearing scrap can be consumed (by recycling, 

processing to recover the cobalt, or downgrading), stocked, 

exported, or disposed of. 

SCRAP CONSUMPTION (RECYCLING AND 

RECOVERY) 

Estimates of new and old scrap consumption were 

made by using information from various sources, which 

included data reported to the U.S. Geological Survey, personal communications with industry representatives, and 

published reports. In 1998, U.S. industry consumed an estimated 1,700 t of new scrap and 1,700 t of old scrap. This 

resulted in a new-to-old-scrap ratio of 50:50 (table 1). 

Recycled cobalt includes cobalt in recycled scrap 

where the cobalt is not necessarily wanted, but is tolerated. 

This is referred to as “downgraded cobalt.” Downgrading 

happens when cobalt-bearing scrap is recycled to a steel or 

to an alloy in which the cobalt is diluted to a residual or 

background level to a point where its unique properties are 

not fully utilized. Cobalt then effectively acts as a substitute for iron, nickel, or other alloying metals. For the purposes of this study, downgraded cobalt was counted as 

scrap consumption rather than as a loss (see definition for 

recycling in the Appendix). 

SCRAP EXPORTS 

The U.S. Census Bureau combined exports of cobalt 

waste and scrap with those of cobalt metal under HTSA category 8105.10.0000. The following procedure was used to 

distinguish cobalt scrap from cobalt metal. Data were available on a monthly basis for individual countries of destination and ports of departure. For each month, a minimum 

price for cobalt metal was determined from a comparison of 

prices published in Platt’s Metals Week and Metal Bulletin 

and unit values of National Defense Stockpile (NDS) cobalt 

awarded by the Defense National Stockpile Center. Exports 

with unit values above this minimum were considered to be 

cobalt metal, and exports with unit values below this minimum were considered to be cobalt scrap. The cobalt content 

of the cobalt metal exports was assumed to be nearly 100 

percent, or roughly equal to the gross weight. The cobalt 

content of the scrap exports was estimated as follows: for 

each month, for each country of destination and port of 

departure, the unit value in dollars per pound was calculated by dividing the free-alongside-ship value by the gross 

weight. The gross weight was then multiplied by the unit 

value divided by Platt’s Metals Week’s monthly average 

spot price for cobalt metal. 
M8 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

In 1998, the United States exported an estimated 200 t 

of cobalt in cobalt-bearing scrap under HTSA category 

8105.10.0000. On the basis of gross weight, most of this 

scrap was sent to Belgium, Canada, China (which included 

Hong Kong), Finland, France, Japan, the Netherlands, and 

the United Kingdom. The remainder was sent to 14 other 

countries. 

Additional cobalt was likely to have been exported in 

scrap listed under other HTSA categories. Following discussions with major foreign refiners of U.S. cobalt-bearing 

scrap and an analysis of exports of nickel waste and scrap 

under HTSA category 7503.00.0000, the total estimated 

cobalt content of exported scrap was increased to 1,800 t, 

and the new-to-old-scrap ratio was estimated to be 50:50. 

UNRECOVERED OLD SCRAP 

In figure 1 and table 1, unrecovered old scrap represents 

cobalt in scrap that has not been recycled either in the United States or elsewhere. The amount of cobalt recycled 

depends on the type of scrap and the price of cobalt (De 

Jonghe, 1996, p. 9-12). An estimate of the amount of cobalt 

in unrecovered old scrap was derived by subtracting old scrap 

consumption and old scrap exports from old scrap supply. 

The following factors could lead to overestimating the 

amount of unrecovered old scrap: an overestimate of the 

amount of old scrap generated that results from products that 

were still being used in 1998 or that had been exported prior 

to 1998, double counting between old scrap generated and 

old scrap imports that results from imported obsolete products that had been manufactured in the United States prior to 

1998, and underestimates of old scrap consumed or exported. 

OLD SCRAP RECYCLING EFFICIENCY 

Recycling efficiency shows the relation between the 

amount of cobalt in used products theoretically available for 

recycling and the amount that is recovered or recycled. By 

definition, this relation is the amount of cobalt in old scrap 

consumed and exported divided by the amount of cobalt in 

old scrap generated, imported, and released from stocks. 

The recycling efficiency for old scrap calculated for 1998 

was 68 percent (table 1). Factors that would lead to underestimating old scrap recycling efficiency are as follows: 

underestimates of the amounts of cobalt-bearing scrap consumed or exported and overestimates of old scrap supply. 

INFRASTRUCTURE OF COBALT SCRAP 

INDUSTRY 

Although the United States is a major cobalt consumer, 

it has not mined or refined a significant amount of cobalt for 

many years. In 1998, only negligible amounts of byproduct 

cobalt were produced as intermediate products from U.S. 

mining operations. U.S. cobalt supply comprised imports, 

releases from industry stocks, sales of excess cobalt metal 

from the NDS, and the recycling of cobalt-bearing scrap. 

The collection and processing of cobalt-bearing scrap 

depended on several factors, such as the type, quality, and 

volume of the scrap. A wide variety of collecting, sorting, 

preliminary processing, and recycling or metal reclamation 

systems was used. Some scrap was handled by dealers, brokers, or waste management companies. Some scrap went 

through other collection, sorting, and processing routes. 

Examples of collecting, sorting, and preliminary processing 

routes for two types of scrap—alloy scrap and batteries— 

are described below. Following collection, sorting, and preliminary processing, most of the cobalt-bearing scrap was 

processed and/or consumed in the United States. Examples 

of scrap processing technologies used in the United States 

are described in the section “Processing of Cobalt Scrap.” 

The remaining cobalt-bearing scrap was exported to foreign 

smelters, refiners, processors, or consumers either directly 

or following some initial processing. 

ALLOY SCRAP 

This category includes new and old scrap of the following types: corrosion- and wear-resistant alloys, magnetic alloys, specialty steels, superalloys, and other cobaltbearing alloys. Scrap metal processors collect, sort, and 

process metal and alloy scrap and then return it to scrap 

consumers for melting (Institute of Scrap Recycling Industries, Inc., 1996, p. 15). Solid pieces of new and old metal 

and alloy scrap are first hand sorted by alloy type. Skilled 

sorters do a preliminary sort on the basis of shape (object 

recognition), color, and weight of the scrap items. If necessary, the items are then tested with one or more of the following methods: response to a magnet, analysis of the 

spark pattern generated when the alloy is ground on an 

abrasive wheel, or chemical or physical analysis by various 

methods (Newell and others, 1982, p. 1–2; Riley, 1990, p. 

576–577). Once the solids have been sorted by alloy type, 

any attachments must be removed and all assemblies must 

be dismantled. Additional processing, such as washing, 

degreasing, chemical milling, shot blasting, pickling, and 

cutting to size, depends on the condition of the scrap and 

the customer's requirements (Meschter, 1990; Monico 

Alloys, Inc., undated). 

Turnings represent the largest quantity, by volume, of 

superalloy scrap generated. Scrap processors collect these 

turnings; qualitatively verify their chemical purity to 

remove materials that would contaminate a superalloy melt; 

crush the turnings into chips; quantitatively assay the chips; 

clean residual cutting fluids and dirt from the chips by kiln 

processing, detergent cleaning, or solvent cleaning; sample 

and analyze the scrap to certify that it meets certain chemical specifications; prepare homogeneous lots if desired; 

densify the chips if desired; and then package the scrap for 

return to the superalloy melter (Lane, 1998). 

Turbine engine parts from dismantled military aircraft 

are an example of cobalt-bearing old scrap. The Defense 

Reutilization and Marketing Service (DRMS) is the U.S. 
COBALT RECYCLING IN THE UNITED STATES IN 1998 

Department of Defense (DOD) agency that disposes of 

excess property received from the military services. The 

DRMS first offers excess military property for reuse within 

the DOD, transfers it to other Federal agencies, or donates 

it to State and local governments and certain nonprofit 

organizations. Property that is not reused, transferred, or 

donated is offered for sale to private companies and individuals (Defense Reutilization and Marketing Service, 

undated). The DRMS periodically holds sealed bid sales 

with offers of high-temperature alloy scrap in the form of 

turbine engine parts. Scrap metal processors are potential 

buyers of this scrap. 

BATTERIES 

The use of rechargeable batteries and the subsequent 

recycling of spent batteries are motivated by the desire to 

conserve natural resources, to reclaim valuable metals, and 

to reduce the levels of hazardous metals released into the 

environment. Battery scrap can be classified into the following broad categories: manufacturing wastes, large wet 

industrial batteries, and small sealed dry-cell consumer batteries. Manufacturing scrap is generally limited in terms of 

the number of sources and battery chemistries at each 

source, a fact that facilitates collection for recycling. In contrast, industrial batteries and, to an even greater extent, consumer batteries become widely dispersed when put into 

products and distributed to end users. As a result, their collection and sorting by battery chemistry is one of the challenges to achieving a high recycling rate. 

In 1998, U.S. collection programs for spent rechargeable batteries were coordinated by a wide variety of entities. 

“Charge Up to Recycle!” was a public education and battery 

recycling program. This program had been developed by the 

Portable Rechargeable Battery Association and was administered by Rechargeable Battery Recycling Corp. (RBRC), 

which was an international nonprofit public service organization funded by manufacturers and marketers of portable 

rechargeable batteries and products. In 1998, the RBRC 

program promoted and implemented the collection of spent 

NiCd batteries from households and businesses. These batteries were collected at an established network of more than 

20,000 retail outlets, 300 community collection centers, and 

1,000 businesses and public agencies. Batteries collected 

under the RBRC program were sent to The International 

Metals Reclamation Co. (INMETCO) for metal recovery. In 

early 2000, RBRC announced that it planned to expand its 

collection program to include Li-ion, NiMH, and small 

sealed lead rechargeable batteries (England, 1999; 

Rechargeable Battery Recycling Corp., 2000). 

Most NiCd battery manufacturers maintained battery 

take-back programs and developed specific arrangements 

with metal recovery facilities to process the batteries 

(Morrow and Keating, 1999, p. 27, 34). Sony Electronics 

M9 

Inc. had a take-back program for their Li-ion batteries. In 

1998, approximately 1 to 2 t of spent Li-ion batteries was 

collected by Sony and sent to the company's Dothan, Ala., 

facility, where they were calcined to remove any residual 

charge. The calcined batteries were then sent to a refiner or 

processor to recover the cobalt (Smith, 1999). 

By 1998, many manufacturers of NiCd battery-powered consumer products, such as Black & Decker Corp. and 

Motorola, Inc., had battery take-back programs and were 

participating in the RBRC program. End-users of industrial 

NiCd batteries generally had arrangements with their suppliers to return spent batteries for recycling. Some municipalities, armed services, and government agencies also ran 

battery collection programs (Biagoni, 1999; Morrow and 

Keating, 1999, p. 28, 34). 

INMETCO collected consumer and industrial NiCd 

batteries under several programs that were developed to 

serve the needs of cellular phone companies, hospitals, 

police departments, libraries, municipalities, local communities, and lead smelters that received spent NiCd batteries 

instead of spent lead batteries. INMETCO collected consumer batteries via a mail-back program, a prepaid container program, the RBRC program, a small package program, 

and "milk runs" (see Appendix). INMETCO had its own 

industrial battery collection program and received industrial batteries collected by waste management companies. In 

addition to batteries from the United States, INMETCO 

received batteries from Canada, Europe, and South America and battery manufacturing scrap from the United States 

and elsewhere (Hanewald, McComas, and Liotta, 1999, 

p. 61–63).

Spent rechargeable batteries collected under various 

programs were either shipped directly to a metal recovery 

facility in the United States or elsewhere or sent to a battery 

processor, also referred to as a “battery breaker” or “secondary battery recycler.” The responsibility of the battery 

processor was to sort the batteries by chemistry and then to 

send them to the appropriate recovery facilities. In some 

cases, the processor also dismantled the batteries, separated 

their components, treated the electrolytes, and/or stored batteries or electrodes prior to shipping them to recovery facilities (Morrow and Keating, 1999, p. 29-30). Kinsbursky 

Brothers, Inc., of Anaheim, Calif., is an example of a battery 

processor. In 1998, Kinsbursky Brothers was permitted to 

process the following cobalt-bearing battery types: Li-ion, 

NiCd, and NiMH (Coy, 1999). 

PROCESSING OF COBALT SCRAP 

A wide variety of technologies are used to process 

cobalt-bearing scrap in the United States. The following are 

brief descriptions of some of the technologies in use in 1998 

for various types of this scrap. 
M10 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

ALLOY SCRAP 

Sorting and processing activities performed by scrap 

metal processors were described previously in the section 

“Infrastructure of Cobalt Scrap Industry, Alloy Scrap.” In 

some cases, alloy scrap required remelting before it could 

be reused. Greenville Metals, Inc., of Transfer, Pa., was a 

specialty alloy producer that offered scrap conversion services. These services entailed remelting customer alloy scrap 

in an electric arc furnace, adjusting its chemical composition, and then returning the scrap to the customer as an alloy 

in the form of shot, pigs, or ingots with a certified uniform 

chemistry. Greenville Metals was able to treat various forms 

of alloy scrap, such as grindings, turnings, and other lowgrade scrap (Greenville Metals, Inc., undated a–d). Additional companies that treated alloy grindings and dusts by 

using hydrometallurgical or pyrometallurgical processes are 

described in the section “Mixed Scrap Feeds.” 

BATTERY SCRAP 

When recycling cobalt-bearing batteries, certain metals, such as the cadmium in NiCd batteries and the aluminum in Li-ion batteries, were first recovered or separated 

from the scrap to facilitate processing the remaining scrap. 

The processes used by INMETCO and OMG Americas, 

Inc., to recycle battery scrap are described in the section 

“Mixed Scrap Feeds.” 

CEMENTED CARBIDE SCRAP 

Many processes for recycling cemented carbide scrap 

were available for use during 1998. The processes could be 

generally classified as either direct or indirect recycling. In 

direct recycling, the cemented carbides were disaggregated, 

and the resulting powder of tungsten carbide and cobalt was 

more or less ready to be used to make new cemented carbide parts. Examples of direct recycling processes include 

bloating, the coldstream process, leach milling with partial 

cobalt removal, and the zinc process. In indirect recycling 

processes, the individual components were recovered and 

purified separately by using chemical methods. Examples 

of indirect recycling processes included chlorination, leach 

milling with total cobalt removal, nitrate and/or nitrate-carbonate fusion, and oxidation-sodium hydroxide leaching. 

In general, the chemical processes had advantages, such as 

the ability to remove impurities, but tended to have higher 

costs, higher energy consumption, lower yields, and more 

waste products than the direct recycling methods. A balance between using indirect chemical recycling and direct 

recycling processes allowed industry to recycle soft and 

hard, contaminated and clean cemented carbide scrap; to 

reduce the overall impurity levels in reclaimed materials; 

and to reduce recycling costs (Kieffer, 1982; Kieffer and 

Lassner, 1987; Stjernberg and Johnson, 1998; Gries, 1999; 

Oakes, 1999). 

In the United States, an estimated 35 percent of 

cemented carbide scrap was recycled by using indirect 

chemical processes, 25 percent was recycled by using the 

zinc process, and 5 percent was recycled by using other 

processes. The remaining 35 percent was not recycled 

(Stjernberg and Johnson, 1998). 

Osram Sylvania Inc. was an example of one U.S. company that used a chemical process to recycle cemented carbide scrap. Tungsten production at Osram’s Towanda, Pa., 

plant was from ore concentrates and tungsten-bearing scrap. 

The concentrates and oxidized scrap were leached with 

sodium hydroxide to produce a sodium tungstate solution, 

which was filtered to remove byproduct sludge that contained cobalt and other metals recovered from the scrap. The 

sludge was treated chemically to separate the metals. Once 

separated, the cobalt was converted to cobaltic oxide, which 

was then reduced by hydrogen to cobalt metal powder. In 

addition to cemented carbide scrap, Osram’s chemical 

process was able to treat other cobalt-bearing scrap, such as 

alloys and catalysts (GTE Products Corp., undated, p. 8–9, 

16–17; Osram Sylvania Inc., undated). 

In 1998, OMG Americas expanded its Apex hydrometallurgical plant in Saint George, Utah, to recycle hard and 

soft cemented carbide scrap. Cobalt compounds and ammonium paratungstate were the products of this recycling 

(Magdics, 1997, p. 17; 1998, p. 19, 22, 31; OM Group, Inc., 

1999, p. 3). More information on the Apex plant is provided in the section “Mixed Scrap Feeds.” 

Some U.S. tungsten processors and cemented carbide 

producers used the zinc process to recycle hard cemented 

carbide scrap. The scrap was first sorted by grade and 

cleaned to remove any brazing or impurities and then 

immersed in molten zinc in the presence of argon gas. The 

molten zinc reacted with the cobalt binder, which caused the 

scrap to expand. The zinc was removed by vacuum distillation and left behind a tungsten carbide and cobalt material, 

which was crushed, milled, and blended. Following chemical analysis and carbon adjustment, the reclaimed powder 

was then ready to press into new cemented carbide parts 

(Kieffer, 1982; Stjernberg and Johnson, 1998). 

DIAMOND TOOL SCRAP 

Small amounts of scrap generated by diamond tool 

manufacturers were recycled, primarily to recover the diamonds. The recovered cobalt was sent to cobalt processors 

or refiners. Used tools were either discarded or downgraded 

to steel (De Jonghe, 1996, p. 9). 

MIXED SCRAP FEEDS 

In 1998, an undetermined number of plants in the United States recovered cobalt and other metals from a mix of 

waste and scrap types. The cobalt-bearing waste and scrap 

treated by these plants included alloys, battery scrap, cakes, 
COBALT RECYCLING IN THE UNITED STATES IN 1998 

dusts, filters, grindings, overspray, powders, residues, slags, 

sludges, slurries, solids, solutions, and spent catalysts from 

the petroleum and chemical industries. Selected plants, the 

processes they used, and the types of scrap treated are 

described in the remainder of this section. 

The OMG Americas Apex plant recovered cobalt from 

a variety of scrap materials, which included alloys, spent Liion and NiMH batteries, Li-ion and NiMH battery manufacturing scrap, spent catalysts from the petroleum and 

polyester fiber manufacturing industries, residues, and other 

cobalt-bearing materials. The general process for treating 

scrap at Apex was as follows: leaching, removal of impurities, solvent extraction, precipitating the cobalt as carbonate, and then drying the carbonate or calcining it to oxide. 

Torched spent battery scrap was shredded, screened, and 

then magnetically separated before processing. Li-ion battery electrode scrap was shredded, calcined, and then 

screened to separate aluminum from frit-grade oxide without hydrometallurgical treatment. Products from the Apex 

plant included cobalt carbonate, cobalt nitrate, cobalt oxide, 

cobalt sulfate solution, frit-grade oxide, lithium-cobalt dioxide, and custom-produced specialty chemicals. The plant 

had the capacity to recycle from approximately 450 to 900 

metric tons per year (t/yr) of cobalt (Magdics, 1997, p. 17, 

19–20, 25–29; 1998, p. 16, 19, 22, 24, 26–31). 

The INMETCO plant in Ellwood City, Pa., used a high 

temperature metal recovery process to treat a wide range of 

nickel-, chromium-, and iron-bearing wastes, which included spent batteries, spent catalysts from oil refining and 

chemical manufacturing, and wastes from the plating, specialty steel, superalloy, and surface-finishing industries in 

the form of cakes, dusts, filters, grindings, mill scale, 

sludges, solutions, and swarf. Cobalt-bearing batteries 

accepted by INMETCO included Li-ion, NiCd, and NiMH. 

Some of the other materials processed by INMETCO also 

contained minor amounts of cobalt. In general, INMETCO 

accepted solid wastes with less than 2 percent cobalt on a 

dry-weight basis and liquid wastes with less than 1,800 milligrams per liter cobalt. 

Spent NiCd batteries were first treated in INMETCO’s 

cadmium recovery furnace to separate cadmium from the 

other metals present, which were primarily nickel and iron. 

At INMETCO’s main metal recovery plant, solid wastes 

were blended with carbon and pelletized by using either liquid wastes or water. The pellets, spent catalysts, and shredded nickel and iron from the batteries were reduced in a 

rotary hearth furnace and then fed into a submerged electric 

arc furnace where they were smelted to extract the metals. 

The molten metal was cast into pigs, which were used as 

remelt alloy by the stainless steel industry. The remelt alloy 

was primarily iron with from 9 to 19 percent chromium, 

from 8 to 16 percent nickel, and a maximum of 0.8 percent 

cobalt. 

The INMETCO process recovered 97 percent of the 

cobalt present in the waste and scrap. In 1991, the Ellwood 

M11 

City plant had the capacity to treat 50,000 t/yr of raw material to produce 21,000 t of remelt alloy with an average 

cobalt content of 0.5 percent. This represented approximately 100 t/yr of cobalt. The INMETCO process also generated slag, which was sold as an aggregate, and flue dust 

and filter cake, which were treated offsite to reclaim lead and 

zinc (Hanewald, Munson, and Schweyer, 1991, p. 842–846; 

Hanewald, Onuska, and Schweers, 1995; International 

Metals Reclamation Co., Inc., The, 1998, p. 1–4, 8–10). 

Agmet Metals, Inc., processed filter cakes, filters, 

grindings, solutions, and spent catalysts that contained primarily cobalt, copper, nickel, and/or zinc. The company 

produced metal oxide products by calcining these materials 

in a natural-gas-fired rotary furnace at its plant in Oakwood 

Village, Ohio. The metal oxides that contained nickel and 

cobalt were exported to Canadian smelters. Agmet also calcined TPA catalyst sludge, as necessary, to remove organics. 

The sludge was then toll-leached by Encycle, Inc., at its 

plant in Corpus Christi, Tex., to remove sodium bromide. 

The final product of this recycling was a cobalt-manganese 

powder that was used as a substitute for cobalt oxide by the 

frit industry (Cassidy, 2000; 2001, p. 2). 

The International Metals & Chemicals Group produced 

a variety of cobalt and nickel compounds from metallic 

feeds, plating cake and solutions, and spent catalyst at its 

PPB Technologies plant in Shelby, N.C. The plant processed 

feed materials by leaching followed by precipitation and filtering (Cassidy, 2001, p. 11). 

The Amax Metals Recovery, Inc., plant in Braithwaite, 

La., processed solutions and sludges that contained cobalt, 

copper, and nickel in soluble or hydroxide form by using the 

technology which is described in the section “Spent Catalysts” (Case, Garretson, and Wiewiorowski, 1995, p. 465). 

The Osram Sylvania process, which is described in the 

section “Cemented Carbide Scrap,” was able to treat various 

types of cobalt-bearing scrap, which included alloys and 

catalysts (Osram Sylvania Inc., undated). 

SPENT CATALYSTS 

In 1998, two companies operated metal recovery 

plants in the United States that used spent cobalt-molybdenum and nickel-molybdenum hydroprocessing catalysts as 

their main source of feed. At Gulf Chemical & Metallurgical Corp.’s Freeport, Tex., plant, spent catalysts and sodium carbonate were roasted in a multiple-hearth furnace to 

burn off the hydrocarbons and some of the sulfur and to 

convert the molybdenum, the vanadium, and the remaining 

sulfur to water-soluble salts. After roasting, the calcine was 

milled, leached with water to dissolve the molybdenum 

and vanadium compounds, and then filtered to separate the 

alumina, cobalt, and nickel solids from the molybdenum 

and vanadium in solution. The solution was treated to produce molybdenum and vanadium compounds. Depending 

on its metal content, the filtercake was sold to cement manufacturers or nickel refineries or smelted onsite in Gulf 
M12 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

Chemical’s electric arc furnace. If smelted onsite, then the 

products were high-grade fused alumina for refractory and 

abrasive applications and an alloy that contained from 37 

to 43 percent nickel and from 12 to 17 percent cobalt, 

which was sold to nickel-cobalt refineries (Gulf Chemical 

& Metallurgical Corp., 1999; Llanos and Deering, 2000, 

p. 764–768).

The Amax plant in Braithwaite, was operated under the 

name CRI-MET and was a partnership between subsidiaries of CRI International, Inc., and Cyprus Amax Minerals Co. This plant used a two-stage pressure-leaching 

process to recover metals from spent hydroprocessing catalysts. Spent catalysts were milled in a solution of sodium 

aluminate and sodium hydroxide. The resulting slurry was 

fed into an autoclave and leached under oxidizing conditions at elevated temperature and pressure to convert the 

sulfur to sulfate, to oxidize the organic compounds, and to 

dissolve the molybdenum and vanadium. The autoclaved 

material was thickened and filtered to separate the liquid 

from the solids. Molybdenum and vanadium were recovered from the liquid and converted to oxides. The solids, 

which contained alumina, cobalt, and nickel, were leached 

a second time at high temperature and pressure with a 

strong caustic to solubilize aluminum. The nickel-cobalt 

solids from the second leach were separated, washed, dried, 

and then shipped to another plant to be calcined. The calcined nickel-cobalt material was then exported to a nickelcobalt refiner (Crnojevich and others, 1990, p. 463–467; 

Case and others, 1995, p. 450–453, 461). 

Spent hydroprocessing catalysts were also processed by 

INMETCO and OMG Americas, as described in the section 

“Mixed Scrap Feeds.” 

Spent cobalt-manganese catalyst residues from the 

production of DMT and TPA were sent to cobalt chemical 

producers, such as OMG Americas and The Hall Chemical 

Co. These companies either reclaimed the metals by producing cobalt chemicals or upgraded the spent catalysts to 

new catalysts, which they then returned to the catalyst user 

(Chemical Marketing Reporter, 1995; Magdics, 1997, p. 

19; Hall Chemical Co., The, undated). As described in the 

section “Mixed Scrap Feeds,” Agmet Metals and Encycle 

converted spent cobalt-manganese catalyst residues into a 

cobalt-manganese powder that was used as a substitute for 

cobalt oxide by the frit industry (Cassidy, 2000). 

OUTLOOK 

The recycling of cobalt-bearing scrap and the recovery 

of cobalt from scrap materials are well-established practices 

for a number of reasons. The relatively high price of cobalt 

compared with that of many other metals and the relatively 

low price of cobalt-bearing scrap compared with that of primary cobalt make recycling and cobalt recovery economic 

and desirable. Concern over potential supply disruptions 

that could result from a high dependence on imports from 

uncertain supply sources has encouraged recycling and 

metal recovery as a way to diversify the sources of raw 

materials for the production of cobalt and tungsten chemicals, metals, and end products. Additional factors that play 

a role in promoting cobalt recycling and recovery include 

environmental regulations; periodic increases in the price of 

cobalt; the desire to conserve resources and energy, to 

reduce mining and mineral processing wastes and the costs 

of disposing of these wastes and of used products, to reduce 

levels of such hazardous materials as cadmium in NiCd batteries from the environment, and to demonstrate an environmentally responsible image. 

World cobalt consumption is expected to continue to 

increase in coming years. Because most cobalt products can 

be recycled, the availability of cobalt-bearing scrap is also 

expected to increase. Future increases in the supply of primary cobalt could negatively impact the amount of cobalt 

that will be recycled. Cobalt production has been increasing 

in recent years and is anticipated to continue to increase at 

a faster rate than that of cobalt demand. The likely response 

to a growing market surplus would be a generally downward 

trend in cobalt prices (Shedd, 2001, p. 20.8). The combined 

effect of a surplus of primary cobalt and low cobalt prices 

would impact the economics of some recycling and cobalt 

recovery processes. The prices at which cobalt recycling or 

recovery would become unprofitable for consumers, processors, and refiners are not available because companies do 

not want to reveal proprietary information related to their 

processing costs. One analyst has stated that chemical 

processors reportedly begin to hold back on using scrap 

when the price of cobalt is below approximately $15 per 

pound ($33 per kilogram) but that a major cobalt refiner 

reportedly has continued to process superalloy scrap when 

the price of cobalt was as low as $10 per pound ($22 per 

kilogram) (Hawkins, 1998). Another analyst has stated that 

there is some evidence that the economics of cobalt recycling and reclamation begin to be impacted when the price 

of cobalt decreases to $12 per pound ($26 per kilogram) but 

that the impact is much greater when prices drop to $10 per 

pound ($22 per kilogram) or lower (Kielty, 2001). 

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M16 FLOW STUDIES FOR RECYCLING METAL COMMODITIES IN THE UNITED STATES 

APPENDIX—DEFINITIONS


apparent consumption. Primary plus secondary production (old scrap) plus imports minus exports plus 

adjustments for Government and industry stock 

changes. 

apparent supply. Apparent consumption plus consumption 

of new scrap. 

catalyst. A substance that changes the rate of a chemical 

reaction without being consumed in the reaction. 

dissipative use. A use in which the metal is dispersed or 

scattered, such as paints or fertilizers, making it exceptionally difficult and costly to recycle or recover the 

metal. 

downgraded scrap. Scrap intended for use in making a 

metal product of lower value than the metal product 

from which the scrap was derived. 

home scrap. Scrap generated as process scrap and consumed in the same plant where generated. 

milk run. A routine trip involving stops at many places. 

new scrap. Scrap produced during the manufacture of metals 

and articles for both intermediate and ultimate consumption, including all defective finished or semifinished articles that must be reworked. Examples of new scrap are 

borings, castings, clippings, drosses, skims, and turnings. 

New scrap includes scrap generated at facilities that consume old scrap. Included as new scrap is prompt industrial scrap—scrap obtained from a facility separate from 

the recycling refiner, smelter, or processor. Excluded 

from new scrap is home scrap that is generated as 

process scrap and used in the same plant. 

new-to-old-scrap ratio. New scrap consumption compared 

with old scrap consumption, measured in weight and 

expressed as a percentage of new plus old scrap consumed (for example, 40:60). 

old scrap. Scrap including (but not limited to) metal articles that have been discarded after serving a useful 

purpose. Typical examples of old scrap are electrical 

wiring, lead-acid batteries, silver from photographic 

materials, metals from shredded cars and appliances, 

used aluminum beverage cans, spent catalysts, and tool 

bits. This is also referred to as postconsumer scrap and 

may originate from industry or the general public. 

Expended or obsolete materials used dissipatively, 

such as paints and fertilizers, are not included. 

old scrap generated. Cobalt content of products theoretically becoming obsolete in the United States in the 

year of consideration, excluding dissipative uses. 

old scrap recycling efficiency. Amount of old scrap recovered and reused relative to the amount available to be 

recovered and reused. Defined as [consumption of old 

scrap (COS) plus exports of old scrap (OSE)] divided 

by [old scrap generated (OSG) plus imports of old 

scrap (OSI) plus a decrease in old scrap stocks (OSS) 

or minus an increase in old scrap stocks], measured in 

weight and expressed as a percentage: 

COS + OSE ×100 

OSG + OSI + decrease in OSS or − increase in OSS 

old scrap supply. Old scrap generated plus old scrap 

imported plus old scrap stock decrease. 

old scrap unrecovered. Old scrap supply minus old scrap 

consumed minus old scrap exported minus old scrap 

stock increase. 

price. Prices for cobalt scrap are not published. The average 

price of cobalt metal in 1998 was used to estimate the 

total value of old scrap consumed. For each type of 

scrap, a percentage was applied to adjust the relative 

value of cobalt contained in the scrap to the price of 

cobalt metal. The total value of net exports of cobalt 

scrap was derived from trade statistics reported by the 

U.S. Census Bureau as follows: total estimated value of 

cobalt scrap exports minus total estimated value of 

cobalt scrap imports. See “Scrap Exports” and “Scrap 

Imports” sections of this report for further information 

on how cobalt scrap trade statistics were estimated. 

recycling. Reclamation of a metal in usable form from scrap 

or waste. This includes recovery as the refined metal or 

as alloys, mixtures, or compounds that are useful. 

Examples of reclamation are recovery of alloying metals (or other base metals) in steel, recovery of antimony in battery lead, recovery of copper in copper sulfate, 

and even the recovery of a metal where it is not desired 

but can be tolerated—such as tin from tinplate scrap 

that is incorporated in small quantities (and accepted) 

in some steels, only because the cost of removing it 

from tinplate scrap is too high and (or) tin stripping 

plants are too few. In all cases, what is consumed is the 

recoverable metal content of scrap. 

recycling rate. Fraction of the apparent metal supply that 

is scrap on an annual basis. It is defined as [consumption of old scrap (COS) plus consumption of new 

scrap (CNS)] divided by apparent supply (AS), measured in weight and expressed as a percentage: 

COS + CNS × 100 

AS 

scrap consumption. Scrap added to the production flow of 

a metal or metal product. 

superalloys. Alloys developed for high-temperature service 

where relatively high mechanical stress is encountered 

and where surface stability is frequently required. 

swarf. Fine metallic particles and abrasive fragments 

removed by cutting or grinding tools.