U.S. GEOLOGICAL SURVEY CIRCULAR 930-M 

International Strategic Minerals Inventory 

Summary Report-Niobium (Columbium) 

and Tantalum 

Prepared as a cooperative effort among earthscience and mineral-resource agencies of 

Australia, Canada, the Federal Republic of 

Germany, the Republic of South Africa, the 

United Kingdom, and the United States of 

America 
Geologic Time Scale 

I Million years Age before present 

Holocene 

Quaternary - 0.01 

Pleistocene 

I- 2 u Pliocene 0 

N r- 5 

Miocene 0 

z r- 24 

Oligocene Tertiary w 

u I- 38 

Eocene - 55 

Paleocene 

I 63 

Late Cretaceous 

Cretaceous u - 96 

Early Cretaceous 0 

N I- 138 

0 Jurassic (/) 

w 205 :E rTriassic 

-240 

Permian 

I- 290 

Pennsylvanian - Carboniferous I- -330 

Mississippian u 

0 I- 360 

N Devonian 0 

w I- 410 ....1 

<( Silurian a.. I- 435 

Ordovician 

I- 500 

Cambrian 

-570 u Late Proterozoic 0 

- 900 N 

0 Middle Proterozoic a: 

w I- 1600 z 1-

0 <( 

a: Early Proterozoic a: 

a.. co -2500 

z :E 

<( <( 

w u 

J: 

w 

a: 

a.. u 

a: 

<( 

I 
International Strategic Minerals Inventory 

Summary Report-Niobium (Columbium) 

and Tantalum 

By Richard N. Crockett and David M. Sutphin 

U.S. GEOLOGICAL SURVEY CIRCULAR 930-M 

Prepared as a cooperative effort among earthscience and mineral-resource agencies of 

Australia, Canada, the Federal Republic of 

Germany, the Republic of South Africa, the 

United Kingdom, and the United States of 

America 

1993 
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas l. Peck, Director 

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 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1993 

Free on application to 

U.S. Geological Survey, Map Distribution 

Box 25286, Bldg. 810, Federal Center 

Denver, CO 80225 

Library of Congress Cataloging in Publication Data 

Crockett, R.N. 

International strategic minerals inventory summary report-niobium (columbium) and 

tantalum I by Richard N. Crockett and David M. Sutphin. 

p. em. - (U.S. Geological Survey circular; 930-M) 

"Prepared as a cooperative effort among earth-science and mineral-resource agencies of 

Australia, Canada, the Federal Republic of Germany, the Republic of South Africa, 

the United Kingdom, and the United States of America." 

Includes bibliographical references. 

1. Niobium ores. 2. Tantalum ores. 3. Strategic materials. I. Sutphin, David M. 

IT. Title. ill. Series. 

TN490.N65C68 1993 

333.8'5465-dc20 92-41231 

CIP 
FOREWORD 

Earth-science and mineral-resource agencies from several countries started the 

International Strategic Minerals Inventory in order to cooperatively gather information 

about major sources of strategic mineral raw materials. This circular summarizes 

inventory information about major deposits of niobium and tantalum, two of the mineral 

commodities selected for the inventory. 

The report was prepared by Richard N. Crockett of the British Geological Survey 

(BGS) of the Natural Environment Research Council and David M. Sutphin of the U.S. 

Geological Survey (USGS). David G. Bate, BGS, provided bibliographi~ assistance, and 

the report was transcribed by Dorothy J. Manley, USGS. The niobium and tantalum 

inventory information was compiled by Richard N. Crockett, BGS, with assistance from 

Richard J. Pantel, U.S. Bureau of Mines (USBM). Inventory records were additionally 

supplied by David A. Buckingham, USBM; Ian S. McNaught, Australian Bureau of 

Resource Sciences (BRS); and D. MacRobbie and J. Lepinis, Energy, Mines & 

Resources, Canada (EMR), Mineral Policy Sector (MPS). Additional contributions to the 

report were made by David A. Buckingham, USBM; Theodore J. Armbrustmacher, 

USGS; Ian R. McLeod, BRS; David C. Findlay, EMR, Geological Survey of Canada; and 

Antony B. T. Werner, EMR, MPS. 

Director 

m 

CONTENTS 

Page 

Fo~word------------------------------------------------------------------------------ TIU 

Abstract------------------------------------------------------------------------------- 1 

Part I-Overview - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 

Introduction----------------------------------------------------------------------- 1 

Background and summary of uses - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3 

Uses of niobium - - - --- -- - --- - --- - - - - - - - - - - - --- - --- -- ---- - - - - - - - - --- --- - - - --- - 4 

Uses of tantalum------------------------------------------------------------- 4 

Recent aspects of supply and demand- --- --- - - - - - - - - - - - ---- - - - - - - ---- - - - - - --- --- ---- - - - 4 

Geology and mineralogy of niobium and tantalum---------------------------------------- 6 

Mining and processing - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7 

Niobium mining and processing - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7 

Tantalum mining and processing- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8 

Distribution of niobium and tantalum deposits - --- - --- ------ -- - - - - - - - - - - - --- -- ---------- - 8 

Carbonatites and other alkaline igneous deposits - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8 

Pegmatite deposits and tin placers- --- - - --- - - - - - - - - - - - - - - - --- - -- --- - - - --- -- - - - - - - 10 

Niobium and tantalum ~sources - - - - - - - - -- - - - - -- -- -- - - - - - - - - - -- --- -- - - -- - - - --- - - - - - - - - 10 

Niobium ~sources ----- - --- - - - ---- -- - - - - - - - - - --- - - - --- - --- -- - - - - - - - - - --- ----- 11 

Tantalum ~sources----------------------------------------------------------- 12 

Niobium and tantalum production ----------------------------------------------------- 13 

Niobium and tantalum exports -- - - - ---- -- - -- - - - - - - - - - - - - - -- - --- -- - - - - - - - - - --- -- - --- - - - 14 

Conclusions----------------------------------------------------------------------- 16 

Part II-Selected inventory information for niobium and tantalum deposits and districts- - - - - - - - - - - - - - 17 

Refe~nces cited - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 34 

Additional ~fe~nces on niobium and tantalum resources--------------------------------------- 35 

References on named deposits and districts - - - - - - - - - - --- - - - --- - --- -- - - - - - --- - - -- --- --- -- 35 

Refe~nces on exploration, mining, and processing --------------------------------------- 36 

FIGURE 1. 

2. 

3. 

4. 

5-7. 

8. 

ILLUSTRATIONS 

Page 

Diagram showing United Nations ~source categories used in this ~port- - - --- - - - - - - - - - 3 

Graph showing world mine production of niobium concentrate, for selected years 

1950-90--------------------------------------------------------------- 5 

Diagram showing schematic cross section through a carbonatite complex - - - - - - --- --- - - 8 

Map showing location and geologic deposit type of the world's major niobium and 

tantalum deposits and districts - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9 

Graphs showing the distribution of world5. Niobium ~sources in pyrochlo~-------------------------------------------- 12 

6. Niobium ~sources in o~s other than pyrochlore ------------------------------- 12 

7. Tantalum resources including an assessment of ~sources associated with tin placers-- 12 

Map showing location of major niobium and tantalum post-mill processing facilities----- 15 

v 
TABLE 1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

TABLES 

Page 

World niobium resources in 1989- - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11 

World tantalum resources in 1989 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11 

Estimated cumulative production of niobium and tantalum contained in concentrates, listed 

by country -------------------------------------------------------------- 13 

World production of ores and concentrates, other than pyrochlore, containing niobium 

and tantalum in 1988------------------------------------------------------ 14 

World production of pyrochlore concentrates in 1988-------------------------------- 14 

World exports of partially processed niobium and tantalum materials in 1988 - - - - - - - - - - - - 16 

Selected information for niobium-tantalum post-mill production facilities- -- - - - - - - - -- ---- 18 

Selected geologic and location information from ISMI records for niobium and tantalum 

deposits and districts ------------------------------------------------------ 22 

Selected production and mineral-resource information from ISMI records for niobium 

and tantalum deposits and districts - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - -- - - ---- - - - 28 

VI 
INTERNATIONAL STRATEGIC MINERALS INVENTORY 

SUMMARY REPORT 

NIOBIUM (COLUMBIUM) AND TANTALUM 

By Richard N. Crockett1 and David M. Sutphin2 

Abstract 

Major world resources of niobium and tantalum are 

described in this summary report of information in the International Strategic Minerals Inventory (ISMI). ISMI is a cooperative data-collection effort of earth-science and mineralresource agencies in Australia, Canada, the Federal Republic 

of Germany, the Republic of South Africa, the United Kingdom, and the United States of America. Part I of this report 

presents an overview of the resources and potential supply 

of niobium and tantalum based on inventory information; Part 

II contains tables of both geologic and mineral-resource 

information and includes production data collected by ISMI 

participants. 

Niobium is used principally as an alloying element in 

special steels and superalloys, and tantalum is used mainly in 

electronics. Minerals in the columbite-tantalite series are 

principal ore minerals of niobium and tantalum. Pyrochlore is 

a principal source of niobium. These minerals are found in 

carbonatite, certain rocks in alkaline igneous complexes, 

pegmatite, and placer deposits. ISMI estimates show that 

there are over 7 million metric tons of niobium and almost 0.5 

million metric tons of tantalum in known deposits, outside of 

China and the former Soviet Union, for which reliable estimates have been made. 

Brazilian deposits, followed by Canadian deposits, contain by far the largest source of niobium. Tantalum production 

is spread widely among several countries, and Brazil and 

Canada are the most significant of these producers. Brazil's 

position is further strengthened by potential byproduct 

columbite from tin mining. Present economically exploitable 

resources of niobium appear to be sufficient for the near 

future, but Brazil will continue to be the predominant world 

supplier of ferrocolumbium. Tantalum, a byproduct of tin 

Manuscript approved for publication September 15, 1992. 1 British Geological Survey (Natural Environment Research Council). 2 U.S. Geological Survey. 

production, has been captive to the fluctuations of that 

market, but resources in pegmatite in Canada and Australia 

make it likely that future increases in the present modest 

demand will be met. 

PART I-OVERVIEW 

INTRODUCTION 

The reliability of future supplies of so-called strategic minerals is of concern to many nations. This 

widespread concern led to duplication of effort in the 

gathering of information on the world's major sources of 

strategic mineral materials. With the aim of pooling such 

information, a cooperative program named International 

Strategic Minerals Inventory (ISMI) was started in 1981 

by officials of the governments of the United States, 

Canada, and the Federal Republic of Germany. They 

were subsequently joined by the Republic of South 

Africa, Australia, and the United Kingdom. 

The objective of ISMI reports is to make publicly 

available, in convenient form, nonproprietary data and 

characteristics of major deposits of strategic mineral 

commodities for policy considerations in regard to shortterm, medium-term, and long-term world supply. This 

report provides a summary statement of the data compiled and an overview of the supply aspects of niobium 

and tantalum in a format designed to benefit policy 

analysts and geologists. Knowledge of the geologic 

aspects of mineral resources is essential in order to 

discover and develop mineral deposits. However, technical, financial, and political decisions must also be 
made, and often transportation and marketing systems 

must be constructed before ore can be mined and 

processed and the products transported to the consumer; 

the technical, financial, and political aspects of mineralresource developments are not specifically addressed in 

this report. This report addresses only the primary stages 

in the supply process for niobium and tantalum and some 

considerations of niobium and tantalum demand. 

The term "strategic minerals" is imprecise. It 

generally refers to mineral ore and derivative products 

that come largely or entirely from foreign sources, that 

are difficult to replace, and that are important to a 

nation's economy, in particular to its defense industry. 

In general, the term relates to a nation's perception of 

vulnerability to supply disruptions, and its concern to 

safeguard its industries from the disruptions of a possible 

loss of supplies. 

Because a mineral that is strategic to one country 

may not necessarily be strategic to another, no definitive 

list of strategic minerals can be prepared. The ISMI 

Working Group decided to commence with commodity 

studies on chromium, manganese, nickel, and phosphate. All of these studies, plus those of platinum-group 

metals, cobalt, titanium, graphite, lithium, tin, vanadium, and zirconium have now been published. Additional studies on niobium (columbium) and tantalum 

(this report), tungsten, and rare-earth oxides and yttrium 

have been subsequently undertaken. A regional survey 

of the strategic minerals of subequatorial Africa has been 

published, and a survey on eastern Europe is underway. 

The data in the ISMI niobium and tantalum inventory were collected from January 1988 to January 1990. 

The report was submitted for review and publication in 

September 1991. The information used was the best 

available to the various agencies of the three countries 

that most directly participated in preparation of this 

report. Those agencies were the Bureau of Mines and the 

Geological Survey of the U.S. Department of the Interior; the Geological Survey of Canada and the Mineral 

Policy Sector of the Canadian Department of Energy, 

Mines & Resources; and the British Geological Survey, 

a component of the Natural Environment Research 

Council. Other ISMI participants from the Bureau of 

Resource Sciences of the Australian Department of 

Primary Industries and Energy; the Federal Institute for 

Geosciences and Natural Resources of the Federal 

Republic of Germany; and the Geological Survey and 

Minerals Bureau of the Department of Mineral and 

Energy Affairs of the Republic of South Africa have also 

assisted with later stages of production. 

No geologic definition of a deposit or district is 

used for compiling records for this report. Deposits and 

2 

districts are selected for the inventory on the basis of 

their present or expected future contribution to world 

supply. Records for all deposits compiled by ISMI 

participants meet this general "major deposit" criterion 

and are included in the inventory. No information is 

provided on deposits that were once significant but 

whose resources are now considered to have been 

depleted. In general, the term "ore" as used, for example, in the resources column of table 9 (Part II), refers to 

mineralized rock that contains an economic or subeconomic quantity of either or both niobium and tantalum in 

the form of minerals such as columbite, tantalite, or 

pyrochlore. 

A special difficulty arises, however, in that most 

of the present world supply of tantalum, and formerly 

that of niobium as well, is a byproduct of tin production. 

Entries are not provided in tables 8 and 9 of Part II for 

deposits or districts primarily worked for tin, such as 

those in Nigeria, Malaysia, or Thailand, where niobium 

or tantalum are important byproducts of the beneficiation 

(processing to improve size distribution or grade) of tin 

ore. The extent of resources associated with such tin ores 

is either not known or not reported, and the amount of 

niobium or tantalum from such sources that reaches 

world markets follows the ups and downs of the tin 

industry and the fluctuating prices of tin. Further information on tin deposits from which niobium or tantalum 

are potential byproducts can be found in the ISMI 

summary report for tin (Sutphin and others, 1990). 

Production of, and trade in, niobium and tantalum 

arising as a byproduct of the beneficiation of tin ore or, 

in Southeast Asia, from the reprocessing of tin-smelting 

slags are, however, included as much as possible within 

other regional or national analyses contained within this 

report. 

The ISMI record collection and this report on 

niobium and tantalum have adopted the international 

classification system for mineral resources recommended by the United Nations Group of Experts on 

Definitions and Terminology for Mineral Resources 

(United Nations Economic and Social Council, 1979; 

Schanz, 1980). The terms, definitions, and resource 

categories of this system were established in 1979 to 

facilitate international exchange of mineral-resource 

data; the Group of Experts sought a system that would be 

compatible with the several systems already in use in 

several countries. Figure 1 shows the United Nations 

(U.N.) resource classification used here. This report 

focuses on category R1, which includes reliable estimates of tonnages and grades of known deposits. The 

familiar term "reserves," which many would consider to 
R* 

IN SITU RESOURCEsQuantities of economic interest 

for the next few decades 

R1 R2 R3 

KNOWN DEPOSITSReliable estimates 

EXTENSIONS OF KNOWN DEPOSITS 

AND NEWLY DISCOVERED DEPOSITSUNDISCOVERED DEPOSITSTentative estimates 

R1E 

~ R1M R1S R2E R2S 

Economically Marginally Subeconomic Economically Subeconomic 

exploitable economic exploitable 

*The capitai''R" denotes resources in situ; a lower case "r" expresses the corresponding recoverable resources for each category and 

subcategory. Thus, r1E is the recoverable equivalent of R1E. This report deals only with R1 and R2, not with R3. 

FIGURE 1. United Nations resource categories used in this report (modified from Schanz, 1980, p. 313). 

be equivalent to r1E or R1E has been interpreted 

inconsistently and thus has been deliberately avoided in 

the U.N. classification. 

It should be noted that, generally, until a deposit 

has been extensively explored or mined, its size and 

grade are imperfectly defined. In many cases, deposit 

size will prove to be significantly larger, sometimes even 

several times larger, than was established when the 

decision to mine was made. Experts with a sound 

knowledge of a deposit and its geologic setting might 

infer that the deposit extends beyond the bounds reliably 

established up to that time. Tonnage estimates for such 

inferred extensions fall into category R2. For major 

deposits, ISMI records show R2 estimates in the few 

cases for which they are readily available. Category R3, 

postulated but undiscovered resources, is not dealt with 

in this report. 

Not all companies or countries report resource data 

in the same way. In this report, all resource data are 

quoted as being in place. The proportion of ore extracted 

in the mining process, termed "mining recovery," 

depends on individual conditions and may vary considerably. However, most niobium and tantalum are produced from open pit mining where recovery from 

in-place ore may be about 75 to 90 percent. In the case 

of tin-bearing placer deposits from which some columbite or tantalite may be extracted, the recovery of 

unbeneficiated ore may be in excess of 90 percent. After 

mining, some part of the mineral content is likely to be 

lost in processing (concentration and separation stages). 

For placer deposits, this is generally not more than 5 

3 

percent, but the metallurgical recovery rates of hard-rock 

ore depend on grain size. 

The World Bank economic classification of countries (World Bank, 1986, p. 180-181), which is based 

primarily on gross national product (GNP) per capita, 

has been used in other ISMI reports to illustrate distribution of resources and production according to economic groupings of countries. This classification was 

chosen because it relies primarily on objective economic 

criteria and does not contain political bloc labels that 

might be perceived differently by different countries. 

Such a classification has not been attempted in this report 

since the concentration of resources and production in 

both commodities into a relatively small number of 

countries and, in the case of tantalum, the link with the 

fluctuating fortunes of the tin industry give such analyses 

little value. 

BACKGROUND AND SUMMARY OF USES 

Niobium and tantalum are relatively rare metallic 

elements and constitute, on average, only about 20 and 

1. 7 parts per million, respectively, of the material 

contained within the Earth's crust. Nevertheless, the 

crustal abundance of niobium is greater than that of some 

familiar metals such as lead and tin. Even tantalum is 

present at a geochemical concentration that is comparable to that of tin. Unlike these metals, however, ore 

deposits in which niobium- or tantalum-bearing minerals 

predominate are rare. 

Niobium and tantalum occupy positions 41 and 73, 

respectively, in the periodic table of chemical elements. 
Confusion has persisted for many years over the alternative names of niobium and columbium for element 41; 

niobium (Nb) is the preferred term in chemistry and most 

other sciences and was officially adopted by the International Union of Pure and Applied Chemistry in 1950. 

The term "columbium" is still used in metallurgy and 

mineral trades3 (Parker and Adams, 1973, p. 443). 

Uses of Niobium 

The principal use of niobium is as an alloying 

element in high-strength, low-alloy (HSLA) steels and 

superalloys. HSLA's are so named because of their 

relatively high strengths that are obtained by the addition 

of less than 1 percent of alloying elements other than iron 

and manganese. There is widespread and increasing use 

of HSLA steels in oil and gas pipeline steels, in lighter 

and more fuel-efficient automobiles, and in major construction such as skyscrapers, bridges and nuclear reactors (Manker, 1981; Miller and others, 1986). Niobium 

is also used as a carbide stabilizer in stainless steels to 

improve their resistance to corrosion when used in 

exhaust manifolds, fire walls, and pressure vessels. 

High-purity ferrocolumbium and nickel-niobium 

are gaining increasingly important applications as alloying elements in superalloys. Nickel-, cobalt-, and ironbased superalloys containing 1 to 5 percent niobium are 

used to make gas-turbine engine components, rocketnozzle subassemblies, and heat-resistant combustion 

equipment (Cunningham, 1985a). 

A possible new market for niobium is in the field 

of superconductors using specialized alloys with titanium (NbTi) or tin (Nb3Sn). Superconducting magnets 

are used as accelerator magnets in high-energy physics 

research, in magnetic-confinement magnets for experimental work in controlled thermonuclear fusion, and for 

medical use in magnetic resonance imaging equipment 

(Gregory, 1984). Although current demand for superconducting materials is relatively low, continued 

research and development is expanding market applications and future demand may arise from magnetohydrodynamics, energy storage, superconduction transmission 

lines, and superconducting computers among others. 

At present, however, the prospects for expansion in 

demand for niobium in the field of superconductors has 

become somewhat uncertain following the discovery of 

3 This double name leads to ambiguities in the nomenclature of chemicals 

and minerals derived from this element. The niobium-rich ore mineral columbite 

is rarely given the name niobite even in those countries in which niobium is the 

element name in common usage. Columbite may be regarded conversely, in 

chemical terms, as a niobate (but rarely, or never, columbate) of iron or 

manganese. 

4 

rare-earth-element-bearing ceramic superconductors that 

promise more favorable performance characteristics. 

Uses of Tantalum 

In the United States, the electronics industry is 

responsible for about 60 percent of domestic tantalum 

consumption (Cunningham, 1985b). In Japan, a comparable figure of about 70 percent reflects the relatively 

greater importance of the manufacture of electronics to 

the economy of that country. The principal electronic use 

for tantalum is in capacitors; tantalum oxide has the 

highest known dielectric constant of any metallic oxide. 

Other electronic uses include rectifiers, amplifiers, oscillators, controls, signal devices, alarm systems, and 

timing devices in which the ability of tantalum to 

conduct alternating current in only one direction and the 

high electrical resistance of some tantalum alloys are 

utilized. 

Tantalum carbide (TaC), alloyed with cemented 

carbides of metals such as tungsten, titanium, or niobium, and used in metalworking machinery, accounts for 

about 16 percent of U.S. consumption of tantalum. 

A growth area in tantalum consumption in the 

United States is in aerospace and other transportation 

applications; 14 percent consumption was reported for 

this sector in 1983. Tantalum, with its high melting point 

of 2,996 °C, strength at elevated temperatures, and 

corrosion resistance, is combined with cobalt, iron, and 

nickel to produce refractory superalloys. Smaller 

amounts of tantalum are consumed in the manufacture of 

chemical process equipment, nuclear reactors, prosthetic 

devices, optical glass, laboratory equipment, and electroplating devices. 

RECENT ASPECTS OF SUPPLY AND DEMAND 

From the viewpoint of many market economy 

countries-notably the United States, most western 

European countries, and the industrialized countries of 

the Pacific rim-supplies of niobium and tantalum are 

strategic in the sense that a high proportion must be 

imported. Neither, however, are critical because substitutions are often possible, although with a cost or 

performance penalty. 

Certain aspects of the recent history of niobium 

and tantalum supply and demand indicate the significant 

changes that are underway and deserve a more detailed 

assessment. For example: 

• Figure 2 shows the significant change in the pattern of 

supply of niobium concentrates that has taken place in 

the last three decades. Nigeria was the main supplier 
40 

c: 

0 ·u 

::J-

.,en 30 0 c: .... 0 Q. ..... 

Q)•!:! 

..... .... ~'al 

C: E 20 Ol-o (.) c: c: co 0 en (.) ::J 

Eo 

::J£ 10 :.c0 

z 

1955 1960 1965 1970 1975 1980 1985 1990 

Year 

FIGURE 2. World mine production of niobium concentrate, for 

selected years 1950-90 (modified from U.S. Bureau of 

Mines, 1987, p. 7 5, with data from Cunningham, 1991 , p. 

17). 

of the niobium requirement of market economy countries until the mid-1960's, but thereafter production in 

Nigeria declined significantly in comparison with that 

in Canada and, recently and more emphatically, in 

Brazil. At present, Western World niobium production is dominated by three producers that mine pyrochlore; the Araxa open pit in Minas Gerais, Brazil, the 

CataHio I open pit operation at Miner~ao Catalao de 

Goias, Goias state, also in Brazil, and the Niobec 

underground mine in Quebec Province, Canada. The 

Brazilian position is currently being further strengthened by the considerable potential for byproduct 

columbite output from tin mining in that country, 

particularly from the large Pitinga tin-dredging operation in Amazonas state. Although Pitinga as a tin 

producer is not included in the survey of niobium 

deposits in tables 8 and 9 in Part II, the U.S. Bureau 

of Mines reports the presence of at least 500,000 

metric tons of Nb20 5 at that locality, and that estimate 

may be too small by a factor of three (Thorman and 

Drew, 1988). 

• Work on other niobium prospects evaluated in recent 

years includes pilot-scale mining on the pyrochlore 

deposit at Lueshe, Zaire; design work for a laboratoryscale pilot plant to process complex ore from the 

Brockman rare-earth-element deposit in Western Australia; and the continuing examination of the Mount 

Weld carbonatite deposit, also in Western Australia. 

At a more advanced stage, a processing plant was 

commissioned in 1987 near Sao Paulo by the Brazilian 

group Paranapanema. By 1990, this plant was 

expected to produce 900 metric tons annually of 

5 

mixed niobium and tantalum oxides (90 percent 

Nb20 5) derived as a byproduct output of ores from 

Pitinga. 

• Other reports have appeared recently reporting the 

discovery of major new resources of niobium or 

tantalum at Motzfeldt in Greenland (Mining Journal, 

1988; Jones, 1988a, p. 71) and Mabounie in Gabon 

(Laval and others, 1988). In neither case does there 

yet appear to have been any serious attempt at economic evaluation, so those deposits are not included 

in the ISMI niobium and tantalum inventory. 

• The United States, while dominating world output of 

refined niobium products as opposed to steelmakinggrade ferrocolumbium, is facing increasing competition from Brazilian production of niobium oxide and 

superalloy-grade additives based on local ores. There 

is also increasingly aggressive competition from countries such as Japan, which, despite a lack of indigenous resources, are setting up their own processing 

facilities. Japan has previously imported most of its 

requirements for niobium metal and specialized alloys 

from the United States, but in 1986 Toho Titanium 

developed a process of chlorination and electron-beam 

melting to produce an anticipated annual output of 20 

metric tons of niobium from ferrocolumbium. 

• Prior to the acceptance of niobium as a major additive 

in special steels in the early 1960's, world demand for 

niobium was met by byproduct columbite concentrates from Nigerian tin production. Following the 

development of large deposits of pyrochlore, especially in Brazil, the contribution of tin-related byproduct columbite ores has become insignificant. While 

maintaining its position as a supplier of niobium ore 

mined in its own right, Brazil will contribute in the 

1990's to a revival of niobium output associated with 

tin production following the startup of a niobiumtantalum processing operation based on concentrates 

from the Pitinga mine. 

• In contrast to niobium, a significant proportion of 

world output of tantalum has always been associated 

with tin production. Tantalum can be recovered in any 

of three processes: concentrates can be produced 

along with those of tin from certain alluvial deposits; 

tantalum can be recovered from furnace slag at certain 

tin smelters; and tin-mining waste can be reprocessed 

to recover various minerals that can contain tantalum. 

The steep fall in tin prices following the financial 

collapse of the International Tin Council in October 

1985 brought about an acceleration in the decline, 

already in evidence since 1980, of tantalum output 

associated with alluvial tin, particularly from Southeast Asian sources. Following the temporary peak in 
tantalum prices experienced in 1979-80, commercial 

processors of tantalum concentrates and tantalum-rich 

slags had built up substantial inventories of raw 

materials, and thus the shortage of raw materials 

following the collapse of the tin price could be met by 

the run-down of such stocks. However, such stocks 

were considerably reduced by the end of 1987, and 

continuing weakness in the tin market will affect the 

tantalum supply position until well into the 1990's. 

• Plans have been announced to rebuild the Thai niobium and tantalum processing plant that was 

destroyed by fire on June 23, 1986, just prior to 

commissioning. 

• During the period 1986 to early 1989 when tin prices 

were exceptionally depressed, increasing demand for 

tantalum was met by enhanced output of tantalite from 

those few mines that either did not produce tin or that 

were able to sustain tantalite output even in the face of 

unfavorable market conditions for tin. The trend 

continues today. In particular, Greenbushes Ltd., in 

southwestern Western Australia, produces tantalite in 

concentrates as well as recovering tantalum oxide 

from high-grade slag derived from the company's tin 

smelter. Until recently, this output was won exclusively from a combination of surface alluvial mining 

and tailings retreatment, but now there is also a deep 

mine at Greenbushes, yet to be brought into production, that has a potential annual capacity of 160 metric 

tons (350,000 pounds) Ta20 5 . Further resources at 

Greenbushes are accessible to hard-rock open-pit 

extraction, and production from this source is reported 

to have commenced in mid-1989. Further developments at Greenbushes are constrained, however, until 

a new grinding and crushing circuit is commissioned, 

at an estimated cost of A$6 million. In Canada, 

Tantalum Mining Corporation (Tanco), a non-tin 

producer, restarted tantalite production at Bernie Lake 

in Manitoba in August 1988; previous production 

ceased in 1982. In Minas Gerais, Brazil, Companhia 

de Estanho Brasil maintains a considerable output of 

tantalite despite the recent poor state of the tin market. 

An annual output of between 34 and 45 metric tons of 

tantalite is converted into oxide at a nearby chemical 

plant (Jones, 1988b, p. 96). It remains to be seen 

whether this diversification in tantalum supply will be 

maintained in the face of any recovery of the tin 

market after 1990. 

• The People's Republic of China is reported to have an 

annual production base of approximately 100 to 200 

metric tons Ta20 5 (Jones, 1989, p. C91), most of 

which is consumed internally. The two most significant sources are the Limu mine in Guangxi Province 

6 

and the Yichun niobium-tantalum mine in Jiangxi 

Province (Werner, 1988). Yichun was reported to 

have been upgraded to treat 1 ,500 metric tons of ore 

per day during 1987, and foreign technical assistance 

was being sought to extend the output of tantalum 

powder at the Ningxia nonferrous metal smelter 

(Jones, 1988b, p. 97). 

• Even less is known concerning the current levels of 

niobium and tantalum output in the former Soviet 

Union. Most production appears to be centered in the 

region of the major alkaline intrusive complexes of 

Lovozero in the Kola Peninsula and Vishnevogorsk in 

the middle Ural region. 

• Both niobium and tantalum are held on the U.S. 

strategic stockpile. In 1988, the stockpile contained 

1,368 metric tons of niobium in the form of concentrates (about 38 percent), ferrocolumbium (19 percent), metal (1.5 percent), and carbide (less than 1 

percent); another 29 percent in concentrate and 11 

percent in ferrocolumbium are designated as nonstockpile grade. Also in 1988, the tantalum stockpile 

contained 1,392 metric tons of tantalum in minerals 

(55 percent), metal (6.5 percent), carbide (1 percent), 

and nonstockpile-grade minerals (37.5 percent). 

• In terms of world production, niobium and tantalum 

are low tonnage commodities, and the amount of 

tantalum that enters world trade is small, even relative 

to niobium. However, at 1989 price levels, the price 

of tantalum concentrates exceeds that of niobium 

approximately by a factor of ten. The change in the 

early 1960's from columbite to low-cost pyrochlore as 

the principal source of niobium, associated with the 

start of production from Araxa in Brazil, dampened 

the price growth for niobium despite a major growth 

in demand for it as a steel additive. In contrast, the 

tantalum price during the same period increased with 

the growth of the capacitor market and lately has 

expanded in response to the demand produced by the 

growth in the use of computers. 

GEOLOGY AND MINERALOGY OF NIOBIUM AND TANTALUM 

All of the minerals that include niobium and 

tantalum as economically important constituents can be 

regarded as multiple oxides or hydroxides in which the 

two elements are chemically combined with a variety of 

other metallic elements. The most important minerals 

from an economic point of view are those of the 

columbite-tantalite series, which is a source of both 

elements, and pyrochlore, which is the primary source of 

niobium. 
Columbite ((Fe,Mn)Nb20 6) and tantalite ((Fe,Mn) 

T~0 ) are similar in chemical composition and atomic 

structure as well as in minerals that have all degrees 

of intermediate composition from ferrocolumbite 

(FeNb20 6) and manganocolumbite ((Mn,Fe)(Nb,Tah 

0 6) to ferrotantalite (FeTa20 6) and manganotantalite 

(MnTa20 6 ). Columbite-tantalite occurs mainly as an 

accessory mineral disseminated in granitic rocks or in 

pegmatites associated with granites. Economic mineral 

concentrations occur where, as in Nigeria or in Southeast 

Asia, weathering has led to residual or placer deposits or 

where, as in the Bernie Lake deposit in Canada, the 

pegmatites themselves contain a particularly high concentration of these minerals. 

The other principal ore mineral is pyrochlore 

((Ca,Nah(Nb,Tah06(0,0H,F)). The ratio of niobium 

to tantalum in pyrochlore is about 200:1 or greater, and 

the mineral therefore has no importance as a source of 

tantalum. Pyrochlore is commonly found in rocks of 

alkaline igneous complexes, frequently in association 

with minerals of titanium, thorium, uranium, and rare 

earth elements. The pyrochlore deposits of Canada and 

Zaire occur in carbonatite and associated alkaline rocks. 

In Brazil, the occurrences are in eluvial deposits resulting from the weathering in place of carbonatites, which 

leaves an enriched concentration of magnetite, apatite, 

and bariopyrochlore (pandaite). 

Other rarer minerals, of small or local economic 

importance, include pandaite (Ba,Srh(Nb,Tih(O,OHh, 

a barium-rich pyrochlore; loparite (Ce,Na,Cah 

(Ti,Nbh06 , the principal niobium mineral occurring in 

the Lovozero alkali rocks of the Kola Peninsula in the 

former Soviet Union; and ixiolite (Ta,Nb,Sn,Fe,Mn)4 

0 8 . Micro lite is a tantalum-rich mineral analogous to 

pyrochlore, but, unlike the columbite-tantalite series, 

few mineral species having compositions intermediate 

between the pyrochlore and microlite end members have 

been recorded, and the characteristic occurrence of the 

latter is in the albitized zones of granite pegmatites and 

is often associated with tantalite or columbite. A 

titanium-bearing oxide, strtiverite (Ti,Ta,Fe)30 6 , is used 

as a low-grade source of tantalum that is recoverable 

from tin-mining wastes in Southeast Asia. Latrappite 

(Ca,Na)(Nb,Ti,Fe)03 is the main ore mineral at Oka, 

Quebec, Canada. 

Prior to the 1970's, and because of the geochemical affinity between niobium and tantalum, concentrates 

from most sources contained mixtures of these elements. 

The upsurge in demand for niobium in the early 1970's 

was not matched by a corresponding trend in tantalum 

demand, and the extra requirement for the former was 

met by exploitation of pyrochlore, a mineral having 

7 

negligible significance as a source of tantalum. This 

considerably reinforced the position of Brazil and Canada as world suppliers of niobium. In the 1980's, a 

modest resurgence in the production of mixed concentrates occurred, but Brazilian predominance is not challenged because that country's rapid emergence as the 

leading world supplier of tin has ensured that byproduct 

niobium-tantalum concentrates are in abundant supply. 

MINING AND PROCESSING 

Niobium Mining and Processing 

Of the existing major pyrochlore mines, the Canadian Niobec is the only underground operation. Two 

other active Brazilian producers, as well as approximately 16 other properties that have been evaluated for 

possible production, employ or would employ open-pit 

mining. The only exception is the Lueshe deposit in 

Zaire where underground mining may commence after 5 

or 6 years of surface mining. 

Beneficiation of pyrochlore ore is carried out 

through crushing and grinding, magnetic separation, 

desliming (removal of extremely fine particles encountered in ore treatment), flotation, leaching, and calcining. Thereafter, the conversion of niobium-rich concentrates into alloys, metal, and compounds can be 

accomplished by various means. Generally, pyrochlore 

concentrates are now used to make ferrocolumbium, 

which is used principally in steelmaking but which can 

also be used as an intermediate step in the manufacture 

of high-purity ferrocolumbium, nickel niobium, and 

niobium metal. 

In Brazil, Companhia Brasileira de Metalurgia e 

Minera<;ao makes steelmaking-grade ferrocolumbium in 

batches from pyrochlore concentrates using aluminum 

powder as a reductant in an exothermic reaction. The 

aluminothermic process involves the preparation of a 

charge consisting of a mixture of pyrochlore concentrate 

containing about 60 percent Nb20 5 , iron oxide in the 

form of hematite (68 percent iron), and aluminum 

powder in the proportions 18:4:6, respectively. Smaller 

quantities of fluorspar and lime are added as a flux. A 

thoroughly mixed charge weighing about 30 metric tons 

is then ignited in a magnesite-lined steel cylinder. The 

reaction time is about 15 minutes during which temperatures of 2,400 oc are attained, and gangue material and 

impurities separate as slag from a ferrocolumbium "button." The normal grade of ferrocolumbium produced 

contains about 66 percent niobium. The process can, 

however, be adapted for the batch production of highpurity ferrocolumbium, nickel niobium, or metallic 
niobium. Process technology at Niobec is similar to that 

in Brazil except that ferrocolumbium containing 60 

percent niobium is the assumed product (U.S. Bureau of 

Mines, 1987, p. 76). 

Outside Brazil, other smaller producers of niobium, such as Shieldalloy at Newfield, N.J., principally 

use an electro-aluminothermic smelting process. 

Tantalum Mining and Processing 

In contrast to niobium, which currently is produced mainly from pyrochlore, mining developments 

associated with tantalum production usually depend 

upon the recovery of other products, generally tin but 

sometimes lithium, for economic viability. The nature of 

the concentrate from which tantalum is recovered may 

vary from a relatively pure tantalite to a concentrate that 

contains a considerable admixture of columbite that 

sometimes approaches a 50:50 niobium to tantalum 

ratio. The degree to which niobium is recovered from 

such mixed concentrates depends upon prevailing market 

prices. 

Both alluvial and residual tin deposits, including 

tantalite, are mined either by primitive hand techniques 

or, in larger units, by hydraulic or dry open-pit methods. 

Pegmatites are mined by either underground or open-pit 

methods, operations that demand a higher degree of 

preliminary rock breaking and crushing than is the case 

for alluvial and residual deposits. Concentration is 

achieved by wet gravity methods followed by gravity, 

electrostatic, or electromagnetic separation from associated minerals. 

A potentially important source of tantalum is slag 

produced at tin smelters (Jones, 1988b). The tantalum 

content of slags depends upon the nature of the original 

ore and upon smelting practice. Smelting of Bolivian tin 

ores, for example, produces no useful tantalum values. 

Material containing more than about 10 percent Ta20 5 , 

produced principally from the Thaisarco smelter at 

Phuket, Thailand, can be processed directly for tantalum 

recovery, but slags produced at Penang, Malaysia, and 

.Mamore, Brazil, contain about 3 percent Ta20 5 and 

require further upgrading that may not be economic 

at times of low tantalum prices. As with tantalite 

concentrates, varying proportions of niobium may be 

recoverable. 

Extraction of tantalum from mineral concentrates, 

slags, or other material is achieved by digestion with 

hydrofluoric acid followed by liquid-liquid extraction 

with methyl isobutyl ketone. The resultant fluotantalic 

acid solution is treated with potassium chloride or 

fluoride to precipitate potassium tantalum fluoride or, 

8 

Satellite vent from tension dike 

(cone-sheet) 

Shear dike (ring di 

of sovite 

Agglomerate, 

carbonatite, 

and lava Tuff, agglomerate, carbonatite, 

phonolite, nephelinite, trachyte, etc. 

FIGURE 3. Schematic cross section through a carbonatite complex (from Krauss and others, 1982a, after Garson, 1966). 

alternatively, with ammonia to produce pure tantalum 

pentoxide. Tantalum metal can be produced from the 

disassociation of potassium tantalum fluoride either by 

electrolysis when molten or by its reduction with molten 

sodium metal. Tantalum pentoxide is used for the manufacture of tantalum carbide by solid state reaction with 

carbon under vacuum or inert conditions at 1 ,600 oc 

(Cunningham, 1985b). 

DISTRIBUTION OF NIOBIUM AND TANTALUM DEPOSITS 

Carbonatites and Other Alkaline Igneous Deposits 

Almost all of the 24 or so major niobium deposits 

identified in table 8 in Part II of this report are associated 

with the mineral pyrochlore, large concentrations of 

which are found in carbonatite or in other alkaline 

igneous or metamorphic rocks. Carbonatite-igneous 

rock composed primarily of calcium and (or) magnesium 

carbonate-is produced from plutonic activity, and 

many of the circular carbonatite complexes in which 

pyrochlore is found represent the deeply eroded roots of 

volcanoes from which the material was originally 

erupted (fig. 3). Carbonatite complexes can be common 

in the provinces in which they occur, but they are 

confined to a few geographic regions (fig. 4). Geographic groupings of carbonatites appear to be correlated 

broadly with rifting in parts of the otherwise stable shield 

areas of the Earth's crust. 
I.e 

160° 120° 

60° 

40° ·-

oo 

20° ·-

40° oo 40° 80° 120° 160° 

GREENLANDfft~. -~ . t( r?r'\r~ ()' /1~,· ·~~ v 

~>.·--'~'(\~~~ ~ ,;\r-~L, w 

, . u.j ·~~ ~~, 

t rlk'~' ' ' . [l ' ' ' h Crev1er N; "'· .. - 1··, << J , /11: (} / 

obec (St Hono "') /-,-~<'">-::::t ~ ~· ;;;vi N . '• , ... ·--• .• r'- · I' emegosenda -- 'Q \\:_'s ·'::----' ~ ,-('/-' ('• ~--..., " v· - \_( StAnd•• . •. " ""1:·'-" . \ o_ __r-' •• , ~ "--.... >.1 \. I I . . I \ Ok __....,., ~ • ' ' '· "' ' I~ . • I _ ~ ?o a d;stdct ' <. · >--· ' ' - r' .. , I · '· - - · 

·~ ~J!a "-fj ~- \r-.... - - '7'·' .. ,_ r--'' r·· ·------ ,. ,-1 t:..,/ o -"". ' • """' • ,. ... '' "'""'. CHINA 

-~~~~ ·,, ~-r~ ' Bayan Obo 

.. , ,.3 ' ,,.c.. , .. ,-~--- ' ; ' .. . . .~ .• I 

~. • I . <-. "'.0 1 )' • • \ ' •' ,. ' -' ~-·_l ~?-\.-.. f'-"- I, /(·/ '· ~/ Sukulu Hills \ ( , - \ • -, AIRE · ·,, ... •. '• .• . . · '' ('f'·-. BRAZIL Luesh~ ::'.! ...... ·( KENYA Vb ! "\'t'V ,; -~~ r' · .. -, Catalao I TA '\)· :!~;>'. t. ' . A . Panda H'll "" .'iP ' ! -. -ctr '· 

' 

.. 0 

J

. • '; ( S · Bin · ~ ec·I'Q \ ~-ri ~ ••• ~agos go Mnma Hill ·~. ~...r . i V't_\ c' Catal8o 

11 

NZANIA ~~-~'-'~· ~- · ...,_ 

(

' •axa •. ' ~ - .... ' . ti ~' Tapira ~ •. \ ~ lOOO 70 500 o· LATITUDE ~~ r MOZAMB AUSTRALIA 

0 

70 I C Geolog;c d . LEGEND Alto Ug~QhUE Brockman ~~ Boseoodaoy loom .~:odesa"'teh '"' Geo 500 1000 KILOMETERS \\. I ! ., AlkaHne comple eposot t e yp Geolog;c depo . n a M G ount Weld ~ ,....--.,.,AJ 

""""' oepoeseot"~;sseoschaheo ood Roh .,_ Ca~bonatlte x • Place• sot type IOenbushe:~ .,_ 

oot necessa"l sto e ' P • ,. Y a\]thontptlve egmatite * Volcan;c \-o 

H ,. • v 

ydrothermal + 

' repl~cement 

40° ·- /~ t,.! 

FioURE 4. Location and geologic deposit type of the world's major niobium and tantalum deposits and districts. Locations and names are from tables 8 and 9 in Part II. 
Alkaline igneous rocks and certain metamorphic 

equivalents are distinguished in that they tend to contain 

a higher proportion of the alkaline elements sodium and 

potassium compared with the average granitic composition of crustal rocks. Envelopes of alkaline rocks may 

surround carbonatite, but in other cases similar alkaline 

rocks may occur in zones that have carbonatite. 

As few as four areally restricted provinces may be 

defined in which carbonatite and alkaline igneous rocks 

are not only present in some abundance but also contain 

significant pyrochlore mineralization (fig. 4). The Laurentian Highlands of the Canadian Shield between the St. 

Lawrence Valley and Hudson Bay and the southeastern 

Brazilian Shield within the states of Goias and Minas 

Gerais at present produce virtually the entire Western 

World's output of niobium. A third carbonatite province 

in several conterminous countries of central Africa, and 

in close proximity to the Great Rift system, contains a 

number of pyrochlore deposits, but resource data are 

available only for the deposit at Lueshe in Zaire. At the 

northwestern extremity of the former Soviet Union, a 

continuation of the Baltic Shield is marked by the Kola 

Peninsula within which the Lovozero Complex (fig. 4), 

a major carbonatite and alkaline complex, probably 

supplies a large proportion of eastern Europe's requirement for niobium. 

Outside these four provinces, scattered carbonatites, some of which have limited niobium resources, 

are known from certain localities and may be associated 

with somewhat more active tectonic zones around the 

margins of other large shields. Examples of this type 

occur in the southwestern United States and around the 

margins of the Siberian Shield in the former Soviet 

Union. As far as is known, the Vishnevogorsk deposit in 

the Ural Mountains is the only such deposit from which 

niobium is being produced. 

Pegmatite Deposits and Tin Placers 

Minerals within the columbite-tantalite series are 

common accessories in granitic rocks, but concentrations 

of economic interest are rare and are confined to certain 

pegmatites. Only a small proportion of world demand for 

niobium is met directly from such pegmatites, which are 

more important as a source of tantalum. Pegmatites at 

Bernie Lake in Manitoba, Canada, and at Greenbushes 

in Western Australia are mined principally for their 

tantalite content. The Alto Ligonha pegmatite in 

Mozambique may prove to be important in the future. 

Indirectly, however, pegmatite is more significant 

as a source of columbite and tantalite. The larger 

proportion of Western World demand for tantalum, in 

10 

particular, is not produced from pegmatite but as a 

valuable byproduct from the treatment of tin-bearing 

placer deposits located in Brazil and Southeast Asia that 

are in turn derived from the deep denudation of former 

pegmatite fields. 

Although not strictly a geological occurrence, the 

link between tin and tantalum production is further 

reinforced by the recovery of tantalum from some 

tin-smelting slags-particularly in Southeast Asia. This 

intimate association with the tin industry and its fortunes 

means that most of the western supply of tantalum 

cannot be itemized in tables 8 and 9 in Part II. Apart 

from Asian tantalum of both placer and smelter origin, 

small quantities are also produced from tin-bearing 

placers in Nigeria and central Africa. 

The status of tantalum production in the former 

Soviet Union and the People's Republic of China is less 

clear. It is uncertain whether pegmatites in these countries are worked specifically for tantalum or in association with other elements. Much of the Soviet Union's 

demand for tantalum may be met from pegmatite deposits within the Kola Peninsula-coincidentally, close to 

the main center of pyrochlore-based niobium production 

in that country. Although three pegmatite fields are 

identified in southern China, there is little information as 

to the contribution they make to that country's output; a 

substantial proportion may be recovered as a byproduct 

of tin-placer mining in the southwestern provinces. 

NIOBIUM AND TANTALUM RESOURCES 

Published data on which it might be possible to 

base world estimates of niobium and tantalum resources 

are, at best, fragmentary and incomplete. In general, 

accurate figures are available only from individual mines 

or prospects in Australia, Brazil, and Canada. Even in 

these three countries, there is no certainty that the 

collective total of such estimates approaches a realistic 

resource estimate for each nation as a whole. For most 

other countries where niobium and tantalum concentrates 

are produced, resource data are not published or have 

never been collected, particularly with respect to nations 

having centrally planned economies and certain others, 

such as Mozambique, that do not publish such data for 

niobium and tantalum. 

Further complicating the assessment of resources 

is the fact that much of world demand for tantalum, and 

some for niobium, is met by the production of these 

elements as byproducts of tin mining and metallurgy. 

Because measuring and classifying niobium and tantalum resources that may exist within the tin sector in 

terms of either the U.N. classification or in parallel 
TABLE 1.-World niobium resources in 1989 

[Estimate of "reserves" is from unpublished data furnished by the U.S. 

Bureau of Mines unless otherwise noted. N .r., not reported. Figures 

are in metric tons of contained niobium] 

U.S. Bureau Total Rl 

Continent Country of Mines estimates 

estimate of known to 

"reserves" ISMI 

North America .... Canada 122,500 1,940,000 

Greenland N.r. 500,000 

United States 1

357,000 262,500 

South America .... Brazil 3,220,000 3,700,000 

Africa ............ Gabon N.r. 500,000 

Kenya N.r. 240,000 

Nigeria2 63,500 N.r. 

Tanzania N.r. 141,000 

Uganda N.r. 182,000 

Zaire 31,700 32,000 

Asia .............. Malaysia2

·

3 900 N.r. 

Soviet Union3 680,000 N.r. 

Thailand2

'

3 5,400 N.r. 

Other economies 

Other market economies4 •••••••• 6,400 N.r. 

Centrally planned economies ..... N.r. N.r. 

U.S. Bureau of Mines estimate 

of world total (excluding 

"uneconomic" U.S. total) 

(excluding Soviet Union) ....... 3,747,000 

(including Soviet Union) ........ 4,124,000 

World total of R 1 resources 

reported in ISMI ............... 7,497,500 

1 Considered an "uneconomic resource" by the U.S. Bureau of Mines. 2 Byproduct of tin output; data not collected by ISMI. 3 Unpublished update of figures previously published by the U.S. Bureau 

of Mines (Cunningham, 1985a). 4 Cunningham (1990a, p. 51). 

systems such as that adopted by the U.S. Bureau of 

Mines are difficult, little attempt has been made to do so. 

In view of the incompleteness of published data 

concerning niobium and tantalum resources that are 

available to ISMI, tables 1 and 2 not only summarize 

such data but also include "reserves" (as well as "reserve 

base") information collected by the U.S. Bureau of 

Mines and published in the annual Mineral Commodity 

Summaries. This information represents a distillation of 

expert opinion within the Bureau. 

Considerable caution should, however, be adopted 

in any line-by-line comparison of ISMI and U.S. Bureau 

of Mines estimates-not least because the incomplete R1 

totals reported to ISMI have in some cases proved to be 

greater than the corresponding U.S. Bureau of Mines 

"reserves," which ostensibly embrace the total for the 

country concerned. Resources are shown for the major 

new discoveries in Motzfeldt, Greenland (tables 1 and 2), 

and in Mabounie, Gabon (table 1). 

11 

TABLE 2.-World tantalum resources in 1989 

[Estimate of "reserves" is from unpublished data furnished by the U.S. 

Bureau of Mines unless otherwise noted. N .r., not reported. Figures 

are in metric tons of contained tantalum] 

U.S. Bureau Total Rl 

of Mines estimates 

Continent Country estimates of known to 

"reserves" ISMI 

North America .... Canada 1,800 5,000 

Greenland N.r. 450,000 

United States 1

1,500 N.r. 

South America .... Brazil 900 N.r. 

Africa ............ Nigeria2 3,200 N.r. 

Zaire 1,800 

Asia .............. Malaysia2

'

3 900 N.r. 

Soviet 

Union3 4,500 N.r. 

Thailand2

'

3 7,300 N.r. 

Australia ...................... 4,500 1,500 

Other economies 

Other market economies4 ••••••• 1,400 N.r. 

Centrally planned economies .... N.r. N.r. 

U.S. Bureau of Mines estimate 

of world total (excluding 

"uneconomic" U.S. total) 

(excluding Soviet Union) ...... 21,800 N.r. 

(including Soviet Union) ...... 26,300 N.r. 

World total of R1 resources 

reported in ISMI. ............. 456,500 

1 Considered an "uneconomic resource" by the U.S. Bureau of Mines. 2 Byproduct of tin output; data not collected by ISMI. 3 Unpublished update of figures previously published by the U.S. Bureau 

of Mines (Cunningham, 1985b). 4 Cunningham, (1990b, p. 171). 

Niobium Resources 

The total of R1 resources determined by ISMI for 

the two largest western niobium producers (table 1), 

Brazil and Canada, is somewhat greater than the corresponding reserves figure published by the U.S. Bureau 

of Mines. In Zaire, the Lues he prospect appears to be the 

most promising pyrochlore deposit within the central 

African carbonatite belt. The U.S. Bureau of Mines 

statement of reserves for 1989 includes a figure for 

Nigeria that is not included within the definition of R1 

resources recognized by ISMI since this figure represents 

a byproduct of that country's tin mining industry. However, for the sake of additional interest, separate figures 

for Malaysia and Thailand- also associated with tin 

production-previously published by the U.S. Bureau of 

Mines in 1985 are included. The world total of R1 

resources determined by ISMI of over 7 million metric 

tons of contained niobium metal is considerably higher 
than the U.S. Bureau of Mines "reserves"4 total of 3.75 

million metric tons and is higher than the 4 million 

metric tons for "reserve base. "5 Closer agreement 

between the U.S. Bureau of Mines and ISMI totals is 

achieved if figures quoted by ISMI for Greenland, 

Gabon, Kenya, Tanzania, and Uganda are not accorded 

status even within "reserve base" by the U.S. Bureau of 

Mines; in view of the high degree of geological certainty 

of the existence of these deposits of niobium, however, 

it is hard to see how they can be properly accorded any 

status less than R1S (subeconomic known deposits) 

within the U.N. classification. 

Tantalum Resources 

Assessing the world resource position for tantalum 

(table 2) is more difficult than for niobium, and a 

comparison between U.S. Bureau of Mines and ISMI 

figures is harder to establish. ISMI data relate only to 

tantalum derived from pegmatite or similar deposits, 

whereas the U.S. Bureau of Mines assessment embraces 

estimates of the tantalum content of tin placers in several 

countries. Even so, the ISMI total for Rl resources far 

exceeds the U.S. Bureau of Mines "reserves" total for 

countries outside the former Soviet Union and China. As 

with niobium, however, the uncertain status of large 

resources in Greenland-possibly to be equated with 

R 1 S-has a distorting effect. If the Greenland figure is 

excluded from the ISMI total, the ISMI figure of 6,500 

metric tons tantalum content in pegmatite deposits alone 

is compatible with the U.S. Bureau of Mines (1990) 

estimate of 21,800 metric tons covering both pegmatite 

and tin-placer deposits. 

Figures 5 through 7 show the distribution of 

niobium and tantalum resources of the U.N. Rl category 

on a worldwide basis. The former Soviet Union and the 

People's Republic of China are, however, excluded 

owing to the complete lack of resource data. Despite a 

level of geologic knowledge of the Motzfeldt deposit that 

justifies inclusion within the Rl category, ISMI experts 

are not convinced that the measurement of resource 

tonnage has been undertaken with concomitant precision; therefore, Greenland totals included in tables 1 and 

2 are not included in figures 5 to 7. 

4 Reserves-That part of the reserve base that could be economically 

extracted or produced at the time of determination (from U.S. Bureau of Mines 

and U.S. Geological Survey, 1990, p. 195). 5 Reserve base-That part of an identified resource that meets specified 

minimum physical and chemical criteria related to current mining and production 

practices, including those for grade, quality, thickness, and depth (from U.S. 

Bureau of Mines and U.S. Geological Survey, 1990, p. 195). 

12 

>- a: 

1-

z 

::::) 

0 

u 

Brazil 

Canada 

Gabon 

Kenya 

Uganda 

Tanzania 

Zaire 

0 1 ,000 2,000 3,000 

THOUSAND METRIC TONS OF 

CONTAINED NIOBIUM 

4,000 

FIGURE 5. Distribution of world niobium resources in 

pyrochlore. 

>- a: 

1-

z 

~ 

0 

u 

United States 

Nigeria1 

Thailand 1 

Malaysia1 

0 100 200 

THOUSAND METRIC TONS OF 

CONTAINED NIOBIUM 

1

Associated with tin. 

300 

FIGURE 6. Distribution of world niobium resources in ores other 

than pyrochlore. 

>- a: 

1-

z 

~ 

0 

u 

Thailand1 

Canada 

Nigeria1 

Zaire1 

Australia2 

Malaysia1 

0 2,000 4,000 6,000 8,000 

METRIC TONS OF 

CONTAINED TANTALUM 

1

Associated with tin. 2Partially associated with tin. 

FIGURE 7. Distribution of world tantalum resources including 

an assessment of resources associated with tin placers. 
NIOBIUM AND TANTALUM PRODUCTION 

Estimated cumulative production of niobium and 

tantalum contained in concentrates by country for the 

years 1971-87 is listed in table 3. For that period, 

Brazil was by far the largest producer of both niobium 

and tantalum followed by Canada for both elements. The 

reported world total in table 3 for both commodities 

indicates that niobium is produced in much greater 

amounts than tantalum and that tantalum production is 

less concentrated among a few countries than is niobium 

production. 

Tables 4 and 5 show world production of, respectively, minerals other than pyrochlore used as a source of 

niobium or tantalum or both and pyrochlore used as a 

source of niobium only. For 1988, the total niobium 

content for all concentrates produced outside the former 

Soviet Union and China was almost 18,000 metric tons 

of which only about 1.2 percent originated from ores 

other than pyrochlore. About 15,200 metric tons (or 85 

percent) of the 1988 production of niobium in concentrate was derived from Brazilian pyrochlore. In 1987, 

there was a temporary depression in world pyrochlore 

production; Brazil's output was half of its 1988 figure, 

but Brazil's contribution to world output of niobium in 

concentrate outside the Soviet Union and China was 

about 79.5 percent. 

The volume of tantalum production in 1988 was 

far smaller than that of niobium (tables 4 and 5), and, 

although the data given in table 4 do not distinguish 

between tantalum-bearing concentrates produced as a 

primary product and those produced as a byproduct of 

tin-mining operations, total world output of tantalum in 

concentrate in 1988 was about 350 metric tons. No 

single country occupies a predominant position as a 

supplier of tantalum comparable to that of Brazil in the 

case of niobium (tables 3-5). The supply of nonpyrochlore concentrates from Spain, Namibia, Canada 

(from mine production or off stockpiles), Brazil, Thailand, and Australia is directed to tantalum rather than to 

niobium production. The output of concentrates from 

Spain and Namibia is negligible, but the other four 

countries, along with Malaysia, account for about 90 

percent of the annual world production of tantalum in 

concentrate. Of these, Brazil and Thailand are the clear 

leaders with production in 1988 of about 187 and 78 

metric tons, respectively. 

A source of niobium and tantalum not included in 

tables 4 and 5 is metal recovered from the refining of tin 

slags. Output from this source is likely to be negligible in 

the case of niobium but is significant with respect to the 

limited amount of world output of tantalum. About 80 

13 

TABLE 3. -Estimated cumulative production of niobium and 

tantalum contained in concentrates, listed by country 

[Figures are in metric tons. Figures do not add to totals shown due to 

rounding. Figures in parentheses are percent of total. Source: U.S. 

Bureau of Mines, 1973-89] 

Cumulative production/ 1971-87 

Country 

Niobium Tantalum 

Brazil ................... 151,816 (81. 7) 1,499 (23.0) 

Canada .................. 27,392 (14.7) 1,290 (19.8) 

Nigeria .................. 4,344 (2.3) 621 (9.5) 

Thailand ................. 588 (0.3) 749 (11.5) 

Australia ................ 503 (0.3) 951 (14.6) 

Zaire .................... 328 (0.2) 335 (5.1) 

Malaysia ................ 295 (0.2) 97 (1.5) 

Rwanda ................. 223 (0.1) 150 (2.3) 

Mozannbique ............. 134 (0.1) 460 (7.1) 

Zinnbabwe ............... 81 (0.0) 212 (3.3) 

Portugal ................. 28 (0.0) 25 (0.4) 

Nannibia ................. 12 (0.0) 13 (0.2) 

Uganda .................. 8 (0.0) 5 (0.1) 

Argentina ................ 4 (0.0) 5 (0.1) 

South Africa ............. 4 (0.0) 4 (0.1) 

Burundi ................. 2 (0.0) 2 (0.0) 

Spain ................... 0 (0.0) 88 (1.4) 

Reported total ....... 185,761 (100) 6,505 (100) 

1 China, the former Soviet Union, and Zambia are believed to have 

niobium and tantalum mineral-concentrate production. 

percent of tantalum from this source ongmates from 

three tin smelters in Southeast Asia-one in Thailand 

and two in Malaysia; the remainder are principally from 

smelters in South Africa and Zimbabwe. Figures provided by the Tantalum-Niobium International Study 

Center located in Brussels, Belgium (Jones, 1988b, p. 

96), suggest that, for about 5 years prior to the collapse of 

the tin price in late 1985, annual production of tantalum 

from slags was between 300 and 450 metric tons thus 

considerably exceeding production from concentrates 

that were never more than 260 metric tons in the same 

period. Production of tantalum in concentrate estimated 

at 353 metric tons for 1988 (table 4) appears therefore to 

have remained more or less constant for several years. 

However, because of the downturn in the tin market, 

production from slags may be reduced to below that for 

concentrates. 

World niobium and tantalum post-mill facilities 

(fig. 8) are located in countries, such as Australia, 

Brazil, and the United States, that have primary mine 

production of concentrates and in countries, such as the 

Federal Republic of Germany, Japan, and the United 

Kingdom, that rely on imports of concentrates. Statistics 

on ferrocolumbium production are not published on a 

systematic basis, and the British Geological Survey 
TABLE 4.-World production of ores and concentrates, other than pyrochlore, containing niobium 

and tantalum in 1988 

[Modified from British Geological Survey, 1990. N.r., not reported] 

Estimated average Estimated metal Type of 

Country ore or content (in percent) Mine production content (in metric tons) 

(in metric tons) concentrate Niobium Tantalum Niobium Tantalum 

Australia .......... Columbite-tantalite 20 33 1120 24.0 39.6 

Brazil ............. Columbite-tantalite 20 30 622 124.4 186.6 

Canada ............ Tantalite 3 30 37 1.1 11.1 

Malaysia ........... Columbite 40 14 N.r. 2 N.r. N.r. 

Stri.iverite N.r. 10 42 N.r. 4.2 

Namibia ............ Tantalite N.r. 14 7 N.r. 1.0 

Nigeria ............. Columbite 43 6 50 21.5 3.0 

Rwanda ............ Columbite-tantalite 30 23 7 2.1 1.6 

Thailand ........... Columbite-tantalite 17 25 124 21.1 31.0 

Stri.iverite N.r. 6 788 N.r. 47.3 

Zaire ............... Columbite-tantalite 27 27 34 9.2 9.2 

Zimbabwe .......... Columbite-tantalite 11 28 _____M ___1_d 18.5 

Total3 •.....•.•......••••••••....... 1,897 210.7 353.1 

1

British Geological Survey estimate based on 1987 production. 2

Zero production recorded in 1988 is presumably the result of a cutback in tin output; 228 metric tons of niobium 

concentrate were produced in 1987. 3

These totals exclude an unknown quantity of niobium and titanium concentrates produced in the former Soviet Union 

and the People's Republic of China. Minor amounts are believed to be produced intermittently in Argentina, Burundi, French 

Guiana, Portugal, Spain, and Zambia. No detailed information is available on the production of tantalum-bearing tin slags. but 

in recent years the major producers have been Malaysia and Thailand, and small amounts have come from Australia, Brazil, 

Nigeria, Portugal, South Africa, and Zaire. 

TABLE 5. -World production of pyrochlore concentrates in 1988 

[Modified from British Geological Survey, 1990] 

Country 

Brazil ........ . 

Canada ....... . 

Total ..... . 

Estimated tonnage 

Mine production Niobium content of niobium 

(in metric tons) (weight percent) in concentrate 

(in metric tons) 

36,200 

5,600 

41,800 

42 

45 

15,204 

2,520 

17,724 

(1990) is able to report regularly from primary sources 

those statistics with respect to only Brazil ( 19, 106 metric 

tons), Japan (704 metric tons), and the reported world 

total (19,755 metric tons). 6 Brazil, by far the largest 

world producer of niobium in concentrate, dominates the 

production of steelmaking-grade ferrocolumbium. However, Canadian pyrochlore may be used as the basis for 

the production of this grade, principally in Japan and 

Luxembourg and somewhat in the United States. Most, 

but not all, of the remaining Western World production 

6 Production data for other countries are proprietary. European smelters, 

in particular, may produce ferrocolumbium only to special order. Apart from 

Japan, whose annual production of ferrocolumbium approached 2,000 metric 

tons for a time in the mid-1970's, no other country is believed to produce 

ferrocolumbium in excess of 1,000 metric tons per year, and the dominance of 

Brazil, especially in the production of steelmaking grades, is unchallenged. 

14 

consists of specialist production of high-purity ferrocolumbium produced from niobium oxide. In the United 

States, Shieldalloy produces both standard and highgrade ferrocolumbium, and Cabot Corporation, Reading 

Alloys, and Teledyne Wah Chang Albany primarily 

produce high-purity grades. In Europe, Murex Ltd., in 

the United Kingdom, Gesellschaft flir Elektrometallurgie 

(GtE) in the Federal Republic of Germany, and Continental Alloys of Luxembourg are the principal suppliers 

of ferrocolumbium, although not necessarily on a regular 

basis. Table 7 in Part II contains selected information on 

niobium and tantalum post-mill processing facilities. 

NIOBIUM AND TANTALUM EXPORTS 

Reports of the export of partially processed niobium and tantalum ores, concentrates, and tin slags from 

the United States, the United Kingdom, the Federal 

Republic of Germany, and Singapore are not significant 

in the context of world supply since these can be 

assumed to be re-exports (table 6). Canada is the biggest 

exporter of partially processed material other than ferrocolumbium (about 4,000 metric tons), and the bulk of 

this tonnage is niobium-rich concentrates derived from 

Niobec pyrochlore ore. The largest markets for Canadian 

pyrochlore in 1988 appear to have been the United States 
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FIGURE 8. Location of major niobium and tantalum post-mill processing facilities. Locations and names are from table 7 in Part IL 
TABLE 6.-World exports of partially processed niobium and 

tantalum materials in 1988 

[Modified from British Geological Survey, 1990] 

Country Description of material 

in national trade return1 

Australia ........... Columbite-tantalite 

Brazil .............. Columbite-tantalite 

Ferrocolumbium 

Canada ............. Niobium and tantalum ores 

Federal Republic Niobium and tantalum ores 

of Germany. Ferrocolumbium 

Malaysia ........... Columbite and tantalite 

Nigeria ............. Columbite 

Singapore .......... Tantalum ores and 

concentrates (re-exports) 

Tin slags3 

Tin slags (re-exports) 

Sweden ............ Ferrocolumbium 

Thailand ........... Columbite and tantalite 

Tin slags3 

United Kingdom .... Ferrocolumbium and 

ferrocolumbium-tantalum 

United States ....... Tantalum ores and 

concentrates 

Zaire ............... Columbite-tantalite 

Exports 

(in metric tons) 

208 

346 

14,352 

4,000 

95 

927 

23 2

126 

125 

1,463 

690 

14 

243 

2

935 

486 

97 

1 Official trade nomenclature varies from country to country, and the 

distinction between "ore" and "concentrate" may be applied inconsistently. 2 Figure for 1987 (British Geological Survey, 1990). 3 Estimates for concentrate from tin slags, primarily used for the recovery 

of tantalum values, are difficult to compare on a country by country basis. Slags 

originating in Thailand contain about 10 percent T~0 , for example, but slags of 

Malaysian origin contain considerably less Ta20 5 • 

(about 2,000 metric tons), Belgium and Luxembourg, 

and the Federal Republic of Germany, which probably 

share most of the remaining 2,000 metric tons. For the 

Federal Republic of Germany; Canada has replaced 

Brazil as principal supplier following the Brazilian 

decision in 1981 to ban exports of pyrochlore so as to 

increase exports of higher value ferrocolumbium (U.S. 

Bureau of Mines, 1987, p. 75). Until the early 1980's, 

the United States imported about 200 metric tons of 

niobium in concentrate from Nigeria-representing 

about 75 percent of Nigeria's output (Krauss and others, 

1982a). The U.S. Bureau of Mines reports that such 

imports are now negligible, and the United States currently is dependent upon material derived from Canadian 

pyrochlore. Japan, the other major importer of niobium 

concentrates (1,300 metric tons in 1987), presumably 

uses nonpyrochlore material, principally of Southeast 

Asian origin. 

Many countries export nonpyrochlore tantalum 

and niobium concentrates. Canada and Australia mine 

specifically for these concentrates; however, concentrates originating from African or Southeast Asian 

sources, in contrast, are derived as a byproduct of the tin 

16 

industry. World trade in all such concentrates involves 

shipment of material whose value depends upon varying 

contents of niobium or tantalum or, usually, both. In 

most cases, however, niobium can be regarded as the 

byproduct within the concentrate because such material 

is valued mainly in terms of its tantalum content. Trade 

flow for partially processed tantalum is particularly 

difficult to determine in view of the inconsistency of 

individual countries' trade nomenclature. In volumetric 

terms, world trade in tantalum-not dependent on pyrochlore concentrates-is much less than that of niobium. 

A German study (Krauss and others, 1982b) suggests 

that Canadian tantalum concentrate is largely shipped to 

the United States. The remaining United States' requirement and also that of Western Europe is met from a 

mixture of Brazilian, African, Far Eastern, and Australian sources. The Japanese requirement appears to be 

met entirely from Far Eastern sources. 

In the case of ferrocolumbium, Brazil is the only 

exporter of this commodity produced from locally mined 

ore; other, minor exports of ferrocolumbium originate 

from smelters in countries having no indigenous ore 

(table 6). Analysis of trade data made available to the 

British Geological Survey suggests that about 19,000 

metric tons of ferrocolumbium and other materials produced by Brazil in 1988 was probably destined for the 

Federal Republic of Germany (4,000 metric tons), Italy 

(4,000 metric tons), the United States (4,500 metric 

tons), Japan (2,700 metric tons), and the United Kingdom (550 metric tons); the balance of 3,250 metric tons 

is harder to account for. A comparison of 1988 with 

1980 export statistics (Krauss and others, 1982a, pl. 5), 

shows that about 1,000 metric tons is shipped to centrally planned economy countries, such as countries of 

the former Soviet Union. The remainder is sent to 

countries that make special steel grades. 

CONCLUSIONS 

Present economically viable resources of niobium 

appear to be more than sufficient to meet future demand. 

The concentration of ferrocolumbium production in Brazil, along with the location there of some of the largest 

deposits of pyrochlore, suggests that Brazil will continue 

to be a primary world supplier. Nevertheless, the ability 

of manufacturers of specialty steels to switch to ferrocolumbium production when necessary and the existence 

of large North American and African pyrochlore deposits 

having mining costs comparable to those of the Brazilian 

operations suggest that niobium is unlikely to become a 

critical material for industrially advanced nations. 
The supply situation for tantalum is more complex. 

Much of world output of tantalum is as byproduct 

captive to tin production; during the 1980's, tantalum 

supply paralleled the ups and downs of the troubled tin 

market. Increased detachment from the tin market may 

come, however, from rising production from pegmatite 

sources in Canada and Australia and the potential for the 

development of similar deposits elsewhere. Therefore, 

supply difficulties will not constrain future increases in 

demand for tantalum. 

PART II-SELECTED INVENTORY INFORMATION FOR 

NIOBIUM AND TANTALUM 

DEPOSITS AND DISTRICTS 

Table 7 contains information on the world's 

niobium- and tantalum-producing facilities made available by the participating agencies. The information is 

primarily from publications of government agencies, 

such as the U.S. Bureau of Mines and the British 

Geological Survey, that report on mineral production 

and sources of mineral supply. 

17 

Tables 8 and 9 contain information from the International Strategic Minerals Inventory record forms for 

niobium and tantalum deposits and districts. Only 

selected items of information about the geology and 

location (table 8) and mineral production and resources 

(table 9) of the deposits are listed here; some of this 

information has been abbreviated. 

Summary descriptions and data are presented in the 

tables essentially as they were reported in the inventory 

records. For instance, significant digits for amounts of 

production or resources have been maintained as 

reported. Data that were reported in units other than 

metric tons have been converted to metric tons for 

comparability. Some of the data in the tables are more 

aggregated than in the inventory records, such as cumulative production totals that for some mines have been 

reported by year or by groups of years. Some of the 

abbreviations used in the inventory record forms have 

been used in these tables; they are explained in the 

headnotes. 
TABLE 7.-Selected information for niobiumAbbreviations used throughout this table include 

Annual capacity includes some or all of the following items (separated by semicolons): annual capacity of material produced in metric tons; 

material produced; and year of capacity estimate. 

Production includes some or all of the following items (separated by semicolons): amount in metric tons of material produced; material 

produced; and year of production. 

- , not reported; t, metric tons 

Producer Latitude Longitude Plant type Feed Process 

AUSTRALIA 

Greenbushes Chemical plant 33°50'S. l16°00'E. Nb concentrates Solvent extraction 

(Western Australia). 

AUSTRIA 

Treibacher Chemische Werke AG 47°30'N. l4°30'E. 

(Seebach). 

BELGIUM-LUXEMBOURG 

Continental Alloys S.A. (CASA) 49°38'N. 06°09'E. Thermit 

(Dommeldange). 

Sadaci N. V. (Ghent, Belgium) Electric furnace 

BRAZIL 

Companhia Brasileira de l9°35'S. 46°56'W. Electron-beam Aluminothermic reaction; 

Metalurgia e Minera~ao (Araxa). furnace. proprietary chemical process. 

Minera~ao Catalao de Goias Ltda. l8°1l'S. 47°56'W. Aluminothermic reaction 

(Catalao, Goias). 

Paranapanema S.A. Minera~ao 00°45'S. 60°W. Nb concentrates Solvent extraction 

Industria e Constru~ao 

(Amazonas). 

CANADA 

Teck Corp. (St. Honore, Quebec) 47°44'N. 69°08'W. 

CHINA 

Liuzhou (Limu) (Guangx{ 24°19'N. 109°24'E. Smelter 

Province). 

GERMANY 

Gesellschaft ftir Elektrometallurgie 49°27'N. ll 005'E. Smelter Nb and Ta concen- Air furnaces, multiple heating 

m.b.H. (GfE) (Ntirnberg). trates and tin slag. roaster. 

H.C. Starck (Goslar) 51°55'N. 10°25'E. Chemistry and Ta and Nb concenfurther processing. trates, Ta and Nb 

containing tin slag, 

Ta containing chemical residues, Ta 

scrap. 

H.C. Starck (Laufenberg) 47°36'N. 08°04'E. Smelter and tin slag .... do ........ 

chlorination. 

ITALY 

Salem-SpA Leghee Metalli 44°25'N. 08°57'E. 

(Genoa). 

18 
tantalum post-mill production facilities 

Annual capacity (metric tons) 

150,000,000; tailings 

100; tin 

58.97; T~05 

50; carbide products 

Not definitely known. Capacity 

information on ferroalloy 

production believed to be at 

least 10,000 metric tons per 

year. 

Not stated for ferrocolumbium 

2,300; Nb20 5 

23,000; ferrocolumbium 

2,800; ferrocolumbium with 

60-70 percent Nb. 

900; Nb205; 1987 

90; Ta20 5; 1987 

500; ferrocolumbium 

Production (metric tons) Comments 

AUSTRALIA-Continued 

21.9; Ta20 5; 1988 

8.82; Nb20 5; 1988 

21.95; T~05 inTa glass; 1988 

Ta20 5 production is scheduled to be 290 

metric tons per year by 1992. 

AUSTRIA -Continued 

A joint venture with Greenbushes of 

Australia to market niobium and tantalum 

carbide products. 

BELGIUM-LUXEMBOURG-Continued 

Ferrocolumbium is only one of several 

products, but plant has long-term 

contracts. 

Reference 

Cunningham 

(1990c). 

Cunningham 

(1990c). 

Cunningham 

(1985a). 

Minor carbon production of ferro- Do. 

17 ,000; Nb20 5 

16,200; ferrocolumbium 

BRAZIL-Continued 

columbium evident in 1985 but is 

believed not to be producing now. 

Principal products are molybdenum and 

ferromolybdenum. 

Produced 85 percent of Brazil's 

ferrocolumbium in 1987. 

Cunningham 

(1990c). 

128; high-purity ferrocolumbium 

2, 700; ferrocolumbium 

2,900; Nb205; 1987 

3,400; Nb20 5; 1986 

Produced 15 percent of Brazil's 

ferrocolumbium in 1987. 

CANADA-Continued 

CHINA-Continued 

Ensminger (1989). 

Cunningham 

(1989). 

Cunningham 

(1989). 

Niobium and tantalum are byproducts of Werner (1988). 

tin smelting. 

GERMANY -Continued 

ITALY -Continued 

19 

Produces niobium and tantalum metal and 

powder and capacitor-grade tantalum 

powder. 

Produces Ta and Nb compounds, oxide, 

metal powder, capacitor grade Ta powder, 

mill products (e.g., wire, sheets, etc.) . 

.... do ....... . 

In 1986, sold to Liguria Gas; since then, 

no ferroalloy production has occurred. 

Cunningham 

(1985a). 

Sexton and 

Calas (1988). 
TABLE 7. -Selected information for niobiumProducer Latitude Longitude Plant type Feed Process 

JAPAN 

Awamura Metal Industry Co. Ltd. 34°53'N. 135°48'E. Submerged furnaces Aluminotherrnic reaction 

(Uji, Kyoto). 

Japan Metals and Chemicals Co. 38°04'N. 139°45'E. 

Ltd. (Oguni, Yamagata). 

Nippon Kokan KK. (Toyama and 36°40'N. 137°ll'E. 

Niigata). 

Taiyo Mining and Industrial Co. 34°44'N. 134°22'E. Thermit 

Ltd. (Ako City, Hyogo). 

Toho Titanium Co. Ltd. 35°19'N. 139°22'E. 

(Chigasaki, Kanagawa). 

RWANDA 

Regie d'Exploitation et de 02°S. 30°E. 

Development des Mines. 

THAILAND 

Thailand Smelting and Refining 07°53'N. 98°24'E. Smelter Tin concentrates 

Co. Ltd. (Thaisarco) (Phuket). 

Thailand Tantalum Industry Corp. orss'N. 98°22'E. "Chemical plant" 

(TTIC) (Phuket). 

UNITED KINGDOM 

London and Scandinavian 53°25'N. Ol 0

20'W. Approximately 20 Nb20 5 , Ta20 5 

Metallurgical Co. Ltd. furnaces of several 

(Rotherham, Yorkshire). types. 

Murex Ltd. (Rainham, Essex) 51°2l'N. 00°36'E. Various types Nb and Ta concen- Aluminotherrnic reaction 

trates. 

UNITED STATES 

Cabot Corp.(Boyertown, Pa.) 40°20'N. 75°38'W. Ta and Nb ores Concentrate-digesting solvent 

extraction. 

Cabot Corp. (Revere, Pa.) 40°3l'N. 75°10'W. 

Fansteel Metals (Muskogee, Okla.) 35°45'N. 95°22'W. Smelter Ore 

Fansteel Metals (North Chicago, 40°50'N. 87°40'W. Fabrication only 

lll.). 

Kennametal Inc. (Latrobe, Pa.) 40°19'N. 79°24'W. Vacuum furnace Carbon reaction in a vacuum 

furnace. 

NRC Inc. (Newton, Mass.) 42°2l'N. 71°12'W. Refinery Columbite, tantalite 

Reading Alloy Inc. (Robesonia, 40°2l'N. 76°08'W. Aluminothermic Metallothermic reduction of 

Pa.). smelter. NbzOs. 

Shieldalloy Metallurgical Corp. 39°32'N. 75°0l'W. Aluminotherrnic reaction 

(Newfield, N.J.). 

Teledyne Wah Chang Albany 44°34'N. 123°00'W. Refinery . ... do ........ 

(Albany, Oreg.). 

20 
tantalum post-mill production facilities-Continued 

Annual capacity (metric tons) 

300; 60-70 percent 

ferrocolumbium. 

130; ferrocolumbium with 60-70 

percent Nb. 

50; Nb metal; 1986 

320; Ta in tin slags 

300; Tllz05 

300; Nb20 5 

Total capacity is approximately 

25,000-30,000 metric tons per 

year of FeA, FeB, FeTi, FeV, 

Cr metal, Bats alloy, and 

melting base. 

2,000; 60-70 percent Ni 

Production (metric tons) Comments Reference 

86; ferrocolumbium 

130; ferrocolumbium 

JAPAN -Continued 

Principal product is ferrochromium. 

Ferrocolumbium production is minor. 

Company mentioned in first edition of 

ferroalloy directory but not second 

(1988). Minor production of ferrocolumbium and several other ferroalloys. 

Small plant produces a variety of ferroalloys. 

Principal product is titanium sponge. 

Niobium metal from this plant is a minor 

product for superconducting magnet 

applications. 

RWANDA-Continued 

State mining corporation created to 

manage 20 mines. 

THAILAND-Continued 

Operated significantly under capacity in 

1988. 

Construction delayed because of a delay 

in supplying the technology by Hermann 

C. Starck of Germany. 

Cunningham 

(l985a). 

Krauss and others 

(1982a); Cunningham (1985a). 

Sexton and Calas 

(1988). 

Sexton and Calas 

(1988). 

Cunningham 

(1987). 

Cunninghatn 

(l990c). 

Cunningham 

(1990c). 

Wu (1989). 

UNITED KINGDOM-Continued 

Output of ferrocolumbium may always 

be limited. 

Produces a variety of ferroalloys, other 

metals, and alloys. 

Krauss and others 

(1982a); Cunningham (1985a). 

Do. 

UNITED STATES-Continued 

21 

Produces niobium and tantalum products Cunningham 

(1990c). 

Produces ferro- or nickel-columbium Do. 

Produces both niobium and tantalum Do. 

products. 

Produces tantalum and niobium rolled Do. 

products and wire tube. 

Produces niobium and tantalum carbide Do. 

products. 

Produces niobium and tantalum metal Do. 

products. 

Produces ferro- or nickel-columbium 

products. 

Associated with London and Scandinavian 

Metallurgical Co. Ltd. of the United 

Kingdom. 

Produces tantalum and several other 

metals. 

Metal Bulletin 

Books Ltd. 

(1988). 
TABLE 8. -Selected geologic and location information from 

[Byproduct niobium and tantalum associated with tin products are not covered by this table; deposits, principally in centrally planned economy 

countries, for which ISMI data are inadequate also are omitted] 

Host rock includes all or some of the following items (separated by semicolons): main host rock type; formation name; geologic age; geologic 

age-dating method; and host rock age. 

Pleistocene . . . . . . . . . . . . PLEIS 

Cretaceous . . . . . . . . . . . . CRET 

Permian . . . . . . . . . . . . . . PERM 

Cambrian ............. CAMB Early ................ E 

Precambrian . . . . . . . . . . . PREC 

Proterozoic . . . . . . . . . . . . PROT 

Archean . . . . . . . . . . . . . . ARCH 

Middle ............... M 

Mississippian ........... MISS 

Abbreviations used throughout this table include 

-, not reported on the ISMI record form 

Ma, Million years 

Ga, Thousand million years 

Part A-Principal niobium mines and deposits 

Site name Latitude Longitude 

Brockman (Western Australia) l8°19'S. 127°46'E. 

Mount Weld (Western Australia) 28°52'S. 22°32'E. 

Araxa (Minas Gerais) l9°35'S. 47°00'W. 

Catalao I (Goias) l8°08'S. 47°48'W. 

Catalao II (Goias) l8°08'S. 47°47'W. 

Seis Lagos (Amazonas) ~ooos. 66°W. 

Tapira (Minas Gerais) l9°53'S. 46°50'W. 

Aley (British Columbia) 56°27'N. 123°43'W. 

Argor (Ontario) 50°50'N. 80°38'W. 

Cargill (Ontario) 49°18'N. 82°49'W. 

Crevier (Quebec) 49°29'N. 72°45'W. 

Lackner Lake (Multi-Minerals) 4r47'N. 83°08'W. 

(Ontario). 

Manitou Islands (Ontario) 46°15'N. 79°35'W. 

Martison Lake (Ontario) 50°19'N. 83°24'W. 

Late ................. L 

Deposit type Host rock 

AUSTRALIA 

Volcanic Volcanic; ARCH, 

EPROT. 

Carbonatite Carbonatite; PROT 

(2.0 Ga). 

BRAZIL 

Carbonatite Quartzite; PREC 

.... do ........ Araxa Group 

.... do ........ .. .. do ........ 

.... do ........ Gneiss and migmatite; Guianese 

Complex. 

.... do ........ Quartzite; Canastra 

Group; PREC. 

CANADA 

Carbonatite Carbonatite; MISS 

.... do ........ Dolomite carbonatite; 

EPROT; K-Ar; 

1,655 Ma. 

.... do ........ Carbonatites; Cargill 

Alkaline Complex; 

PREC; K-Ar; 1,745 

Ma. 

Alkaline complex Nepheline syenite; 

LPROT; K-Ar; 879 

Ma. 

.... do ........ Ijolite; MPROT; 

K-Ar; 1,090 Ma. 

.... do ........ Fenite; LPROTCAMB; K-Ar; 570 

Ma. 

Carbonatite Residuum; CRET 

Carbonatite; PROT 

22 

Age of mineralization 

EPROT 

PROT (2.0 Ga) 

LCRET 

Unknown 

. ... do ........ 

MISS 

EPROT; K-Ar; 1,655 Ma 

PREC; K-Ar; 1,745 Ma 

CRET 

LPROT; K-Ar; 879 Ma 

MPROT; K-Ar; 1,090 Ma 

LPROT-CAMB; K-Ar; 570 Ma 

PROT;CRET 
ISM/ records for niobium and tantalum deposits and districts 

Abbreviations for mineral names (after Longe and others, 1978, p. 63-66): 

Aegirine . . . . . . . . . . . . . . AGRN 

Albite . . . . . . . . . . . . . . . . ALBT 

Allanite ............... ALNT 

Amphibole ............ AMPB 

Ankerite . . . . . . . . . . . . . . ANKR 

Apatite . . . . . . . . . . . . . . . APTT 

Arfvedsonite . . . . . . . . . . . AFVD 

Armstrongite . . . . . . . . . . . ARMS 

Astrophyllite . . . . . . . . . . . ASPH 

Barite . . . . . . . . . . . . . . . . BRIT 

Bastnaesite . . . . . . . . . . . . BSNS 

Beryl ................ BRYL 

Biotite . . . . . . . . . . . . . . . BOTT 

Calcite . . . . . . . . . . . . . . . CLCT 

Cassiterite . . . . . . . . . . . . . CSTR 

Catapleiite. . . . . . . . . . . . . CTPL 

Chlorite .............. CLRT 

Clay ................. CLAY 

Columbite . . . . . . . . . . . . . CLMB 

Crandallite . . . . . . . . . . . . CRND 

Dolomite .............. DLMT 

Elpidite. . . . . . . . . . . . . . . ELDP 

Euxenite .............. EXNT 

Feldspar . . . . . . . . . . . . . . FLDP 

Fersmite . . . . . . . . . . . . . . FRSM 

Fluorite. . . . . . . . . . . . . . . FLRT 

Gadolinite . . . . . . . . . . . . . GDLN 

Garnet . . . . . . . . . . . . . . . GRNT 

Gittinsite .............. GTTN 

Goethite .............. GTHT 

Hematite .............. HMTT 

Ilmenite . . . . . . . . . . . . . . ILMN 

Kaolin ............... KOLN 

Lepidolite . . . . . . . . . . . . . LPDL 

Magnetite ............. MGNT 

Microcline . . . . . . . . . . . . MCCL 

Micro lite. . . . . . . . . . . . . . MCRL 

Monticellite. . . . . . . . . . . . MNCL 

Part A-Principal niobium mines and deposits-Continued 

Monazite. . . . . . . . . . . . . . MNZT 

Muscovite . . . . . . . . . . . . . MSCV 

Narsarsukite . . . . . . . . . . . NRSR 

Nepheline ............. NPLN 

Niocalite . . . . . . . . . . . . . . NOC 

Pandaite . . . . . . . . . . . . . . PNDT 

Perovskite ............. PRVK 

Phlogopite ............. PLGP 

Plagioclase . . . . . . . . . . . . PLGC 

Pyrite ................ PYRT 

Pyrochlore . . . . . . . . . . . . PCLR 

Pyroxene .............. PRXN 

Pyrrhotite . . . . . . . . . . . . . PYTT 

Quartz ............... QRTZ 

Richterite ............. RCHT 

Riebeckite. . . . . . . . . . . . . RBCK 

Rutile ................ RUTL 

Siderite . . . . . . . . . . . . . . . SDRT 

Simpsonite . . . . . . . . . . . . SMPS 

Sphalerite . . . . . . . . . . . . . SPLR 

Spodumene . . . . . . . . . . . . SPDM 

Sulfides . . . . . . . . . . . . . . SLPD 

Tantalite .............. TNLT 

Thorite . . . . . . . . . . . . . . . THRT 

Titanite. . . . . . . . . . . . . . . TINT 

Tourmaline ............ TRML 

Uraninite .............. URNN 

Vlasovite . . . . . . . . . . . . . VLSV 

Wodginite ............. WDGN 

Wollastonite . . . . . . . . . . . WLST 

Zircon. . . . . . . . . . . . . . . . ZRCN 

Tectonic setting Local environment Principal mineral assemblages References 

Geosynclinal sediments 

and volcanics marginal 

to mobile zone. 

Associated with Laverton 

tectonic zone imposed on 

greenstone-granite terrane. 

Continental margin 

Intracratonic 

Canadian Shield 

Intracratonic 

Intracratonic 

.... do ....... . 

AUSTRALIA-Continued 

Stratabound mineralization in steeply 

dipping tuff-lava-sediment sequence. 

Enrichment in residual zone over 

carbonatite body. 

CLMB, TNTL, PCLR, ZRCN, BSNS, 

CSTR, SPLR, FLRT, and others. 

APTT, MGNT, ILMN, PCLR, MNZT 

Roberts (1988). 

Willett and others (1988). 

BRAZIL-Continued 

Harben (1984). 

SDRT, ANKR, DLMT, BRIT, GTHT, Woolley (1987). 

PYRT, Nb-RUTL. 

PCRL, PNDT Do. 

CANADA-Continued 

Carbonatite-syenite complex intruding 

Cambrian to Devonian sedimentary 

rocks. 

Carbonatite dike cutting Precambrian 

granulitic rocks of the Kapuskasing 

structural zone. 

Kapuskasing "High" 

Anorogenic alkaline intrusion 

emplaced in migmatitic metasedimentary rocks. 

Alkaline complex emplaced in 

Archean granitic gneiss of the 

Kapuskasing structural zone. 

Alkaline stock emplaced in 

Proterozoic gneissic rocks. 

Proterozoic carbonatite complex 

emplaced in Archean metamorphic 

rocks. 

FRSM, PCLR, CLMB, DLMT, CLCT, Mader (1986). 

APTT, CLRT, RUTL, AMPB, PYRT, 

rare earth carbonates. 

PCLR, CLMB, MGNT, HMTT, DLMT, Fielder (1970). 

APTT, RBCK, PLGC. 

APTT; minor: GTHT, SDRT, MGNT, Sage (1988). 

CRND; PYRT. 

PCLR, ALBT, MCCL, NPLN, BOTT; Gagnon and Gendron (1981). 

Urano-PCLR, CLCT, BOTT. 

PCLR, MGNT, APTT, PRXN, NPLN Ferguson (1971). 

PCLR, K-FLDP, PRXN, BOTT, CLCT, Do. 

APTT, MGNT, PYRT, PYTT, URNN. 

PCLR, APTT, MGNT, GTHT, HMTT, Do . 

CLAY, CLCT, DLMT, BSNS. 

23 
TABLE 8. -Selected geologic and location information from 

Site name Latitude Longitude Deposit type Host rock Age of mineralization 

CANADA-Continued 

Nemegosenda (Ontario) 48°01'N. 83°05'W. Alkaline complex Fenitized gneiss; MPROT 

ARCH. 

Syenite; MPROT; 

Rb-Sr; 1,015 ± 63 

Ma. 

Niobec (St. Honore) (Quebec) 48°32'N. 71°10'W. Carbonatite Carbonatite; LPROT; 

K-Ar; 650 Ma. 

Oka district (Quebec) 45°30'N. 74°02'W. .... do ........ Sovite; CRET; K-Ar; CRET; K-Ar; 116 ± 4 Ma 

116 ±4 Ma. 

St. Andre (Quebec) 45°34'N. 74°17'W. .... do ........ Carbonatite; CRET 

Strange Lake (Newfoundland) 56°19'N. 64°07'W. Alkaline complex Altered peralkaline MPROT 

granite; MPROT; 

K-Ar; 1,270 ± 30 

Ma. 

Thor Lake (Northwest Territories) 62°06'N. l12°36'W. .... do ........ Syenite; EPROT; EPROT; U-Pb; 2,094 ± 10 Ma 

U-Pb; 2,094 ± 10 

Ma. 

CHINA 

Bayan Obo (Inner Mongolia) 41°45'N. l10°E. Hydrothermal Dolomite; Y8 Pre-PERM 

replacement. (MPROT). 

Dolomite; MPROT 

GREENLAND 

Sarfartoq (West Greenland) 66°30'N. 51°15'W. Carbonatite Granulites; ARCH LPROT; 600 Ma 

Gneiss; PROT 

KENYA 

MrimaHill 04°30'S. 39°16'E. Carbonatite 

TANZANIA 

Panda Hill (Mbeya) 08°59'S. 33°14'E. Carbonatite 

UGANDA 

Sukulu Hills (Buganda) 00°29'N. 33°12'E. Carbonatite 

UNITED STATES 

Bear Valley placers (Idaho) 44°2l'N. 115°24'W. Placer Black sands derived PLEIS 

from Idaho batholith; PREC. 

Gem Park Complex (Colorado) 38°15'N. 105°32'W. Carbonatite dikes Igneous rocks and CAMB 

carbonatites. 

Precambrian metamorphic rocks. 

McClure Mountain Complex 38°21'N. 105°28'W. Carbonatite Syenite and ijolite; CAMB (about 520 Ma) 

(Colorado). CAMB; 535 ± 5 

Ma. 

Gneiss and amphibolite; PROT; 1.6-

2.5 Ga. 

Powder Hornllron Hill deposit 38°16'N. 107°03'W. .... do ........ Carbonatite plug into PREC 

(Colorado). pyroxenites. 

24 
ISM! records for niobium and tantalum deposits and districts-Continued 

Tectonic setting 

Intracratonic 

Intracratonic; Saguenay rift 

zone. 

Intracratonic; St. Lawrence 

Valley rift system. 

.... do ....... . 

Intracratonic 

Intracratonic 

Intracontinental rifting 

(800 Ma). 

Zone of weakness in 

Precambrian shield. 

Local environment Principal mineral assemblages References 

CANADA-Continued 

Anorogenic alkalic complex emplaced PCLR, PRXN, APTT, MGNT, WLST, Ferguson (1971). 

in gneissic rocks of the Kapuskasing GRNT. 

structural zone. 

Carbonatite and related alkaline rocks 

that have intruded Proterozoic 

metamorphic rocks. 

Carbonatite and related alkaline rocks 

emplaced in Proterozoic gneiss. 

Carbonatite emplaced in granitic 

rocks. 

Anorogenic peralkaline granite 

emplaced in Proterozoic gneissic 

granitoid rock. 

Anorogenic Proterozoic alkaline 

complex emplaced in Archean 

granitic and metasedimentary rocks. 

PCLR, CLMB, APTT, BOTT, MGNT, Gagnon and Gendron (1981); 

DLMT, CLCT, PRXN, ZRCN, HMTT, Vallee and Dubuc (1970). 

PYRT, PYTT. 

PCLR, APTT, PRXN, BOTT, MGNT, Gold and others (1967). 

MNCL, PRVK, RCHT, NOC. 

PCLR,FLRT 

GTTN, ELDP, VLSV, CTPL, ARMS, Unpublished data. 

NRSR, ASPH, ZRCN, PCLR, FLRT, 

BSNS, HMTT, MNZT, AGRN, RBCK, 

ALBT,SDRT,TTNT,GDLN,ALNT, 

THRT, SLPD. 

CLMB, BSNS, ALNT, ZRCN, MNZT, Trueman and others (1988). 

AMPB, BOTT, K-FLDP, ALBT, 

MGNT, FLRT. 

CIDNA-Continued 

Hydrothermal replacement near the 

top of a system associated with an 

unexposed alkaline-carbonatite 

pluton. 

MGNT, HMTT, FLRT, MNZT, BSNS, Drew and others (1990). 

PLGP, DLMT. 

GREENLAND-Continued 

Hydrothermal activity gave rise to 

several phases of mineralization in 

veins and shear zones. 

PCLR, ZRCN, Nb-RUTL, DLMT- Woolley (1987). 

ANKR, APTT, PLGP, RCHT-AFVD, 

MGNT. 

KENYA-Continued 

PCLR, PNDT, MNZT 

TANZANIA-Continued 

UGANDA-Continued 

UNITED STATES-Continued 

ILMN, MGNT, GRNT, TINT, MNZT, Savage (1961). 

ZRCN, CLMB, EXNT. 

Woolley (1987). 

Intruded into Proterozoic metamorphic Ti-MGNT, BSNS, MNZT Do. 

rocks. 

DLMT, ANKR, SDRT, CLCT, PCLR, Staatz and others (1979). 

APTT, MGNT, ILMN, HMTT, GTHT, 

PYRT, RUTL, ZRCN, MNZT, FLRT, 

BOTT, BRIT. 

25 
TABLE 8. -Selected geologic and location information from 

Site name Latitude Longitude Deposit type Host rock Age of mineralization 

ZAIRE 

Bingo (Upper Zaire) 00°32'N. 29°19'E. Carbonatite Pyrochlore 

carbonatite. 

Lueshe (Kivu) 01°00'S. 29°00'E. .... do ........ . ... do ........ 

Part B-Principal tantalum mines and deposits 

Site name Latitude Longitude Deposit type Host rock Age of mineralization 

AUSTRALIA 

Greenbushes (Western Australia) ll5°59'E. Pegmatite Pegmatite; ARCH ARCH; 2.53 Ga 

CANADA 

Bernie Lake (Manitoba) 95°27'W. Pegmatite Albitic aplite; ARCH ARCH 

MOZAMBIQUE 

Alto Ligonha (Zambezia) Pegmatite CRET 

26 
ISM/ records for niobium and tantalum deposits and districts-Continued 

Tectonic setting Local environment Principal mineral assemblages References 

ZAIRE-Continued 

Part B-Principal tantalum mines and deposits-Continued 

Tectonic setting Local environment Principal mineral assemblages References 

AUSTRALIA -Continued 

Metamorphosed sediments 

and mafic volcanics. 

Emplacement of rare-earth-bearing 

pegmatites during shearing and 

metamorphism. 

CSTR, TNTL, SPDM, BRYL, KOLN, Blackley (1980). 

stibio-TNTL. 

CANADA-Continued 

Bird River greenstone belt Internal zones within a complex WDGN, SMPS, MCRL, TNTL, ALBT, 

QRTZ, MSCV, APTT, TRML, MCCL, 

CSTR, ILMN, ZRCN, SPDM, LPDL, 

SLPD. 

pegmatite body. 

MOZAMBIQUE-Continued 

27 
TABLE 9. ~Selected production and mineral-resource information 

[Byproduct niobium and tantalum associated with tin production are not covered by this table; deposits, principally in centrally planned economy 

countries, for which ISMI data are inadequate also are omitted] 

Abbreviations used throughout this table include 

-, not reported on the ISMI record form 

t, metric tons 

REB, rare earth elements; REO, rare earth oxides 

cone, concentrate 

kg/t, kilograms per metric ton 

Part A-Principal niobium mines and deposits 

Site name 

Brockman (Western 

Australia). 

Mount Weld (Western 

Australia). 

. Araxa mine (Minas Gerais) 

Catalao I (Goilis) 

Catalao II (Gohis) 

Seis Lagos (Amazonas) 

Tapira (Minas Gerais) 

Aley (British Columbia) 

Argor (Ontario) 

Cargill (Ontario) 

Crevier (Quebec) 

Lackner Lake (MultiMinerals) (Ontario). 

Manitou Islands (Ontario) 

Year of 

discovery 

1973 

1973 

1954 

1894 

1894 

1980 

1960 

1975 

1981 

1954 

1952 

Year of first 

production 

None 

None 

1961 

1976 

1985 

None 

None 

None 

None 

None 

1954 

Mining 

method 

N 

N 

s 

s 

s 

N 

N 

N 

N 

N 

u 

Elements and minerals 

of economic interest 

Annual production (in 1 ,000 t) 

AUSTRALIA 

Nb, Ta, Y, Zr, Hf, 

Ga, REB. 

Nb,REE,Ta,P, Y 

BRAZIL 

Nb Ore: 3,350; 2.5 percent Nb20 5 ; 1984; Ace 

Leach cone: 0.14; 60.0 percent Nb20 5 ; 1984; Ace 

Fe-Nb cone: amount not published; 66.0 percent Nb20 5 ; 

1984. 

Nb Ore: 1.6; Nb grade not available; 1985; Ace 

Nb Ore: 1.1; Nb-Ta grade not available; 1985; Est 

CANADA 

Nb,REE 

Nb 

Nb,P 

Nb,Ta 

Nb, Fe, P, U, REB 

Nb,U,P 

28 
from ISM! records for niobium and tantalum deposits and districts 

Abbreviations for mining method are S, surface; U, underground; N, not yet producing. 

Annual production and cumulative production figures are reported as ore or concentrate. The descriptors that follow are separated by semicolons 

and, in order, are annual and cumulative production in thousand metric tons; grade of reported material; year of reported production; and 

(where reported) accurate (Ace) or estimated (Est). Years for reported cumulative production are in parentheses. 

Resources includes, for various resource categories, some or all of the following items (separated by semicolons): ore or other reported category; 

resource in thousand metric tons; U.N. resource classification (see fig. 1; United Nations Economic and Social Council, 1979; Schanz, 1980); 

grades of one or more commodities; and year of estimate. 

Part A-Principal niobium mines and deposits-Continued 

Cumulative production 

(in 1,000 t) Resources (in 1,000 t) 

AUSTRALIA-Continued 

Ore: 4,290; R1E; 0.44 percent Nb20 5 ; 0.027 percent Ta20 5 , 0.124 percent 

Y20 3 , 1.04 percent Zr02 , O.Oll percent Ga; 1985. 

Ore: 5,000; RIE; 0.44 percent Nb20 5 ; 0.027 percent T~0 , 0.124 percent 

Y20 3 , 1.04 percent Zr02 , O.Oll percent Ga, 0.035 percent Hf, 0.09 percent 

REO; 1986. 

Ore: 7 ,400; 9.4 percent REO (5 percent cutoff); 1988 

Ore: 6,100; 0.33 percent Y20 3 (0.33 percent cutoff); 1988 

Ore: 22,800; 1.86 percent Nb20 5 (1 percent cutoff); 1988 

Ore: 2,200; 0.0999 percent Ta20 5 (0.05 percent cutoff); 1988 

Ore: 250,000; 18 percent P20 5 (10 percent cutoff); 1988 

Ore: 39,000; 2.5 percent CeO, 1.36 percent LaO, 0.12 percent Y20 5 ; 1988 

Ore: 273,000; 0.9 percent Nb20 5 ; 1988 

Ore: 145,000; 0.34 percent Ta20 5 ; 1988 

BRAZIL -Continued 

Ore: 131,612; R1E; 2.5 percent Nb20 5 ; 1979 

Ore: 288,335; R2E; 2.5 percent Nb20 5 ; 1979 

Ore: 10,000; 1.3 percent Nb20 5 ; 1984 

No data published 

Ore: 60,000; 1.5 percent Nb20 5 ; 1976 

CANADA-Continued 

No data published 

Ore: 50,000; 0.52 percent Nb20 5 ; I970 

Ore: 56,700; RIM; 20 percent P20 5 ; I976 

Ore: 7 ,600; RIM; 31.4 percent P 20 5 ; I987 

Ore: >900; R1S; 0.015 percent U30 8 ; 0.07 percent Nb20 5 ; 1 percent REE; 

I977. 

Ore: 15,200; R1S; 0.189 percent Nb20 5 , 0.02 percent Ta20 5 ; 1981 

Ore: 33,566; R1S; 0.198 percent Nb20 5 , 21.3 percent apatite, 13.7 percent 

magnetite; 1968. 

Ore: 4,558; R1S; 0.173 percent Nb20 5 , 21.9 percent apatite, 69.6 percent 

magnetite; 1968. 

Ore: 45,360; R1S; 0.26 percent Nb20 5 ; 1968 

Ore: 798; R1S; 0.9 percent Nb20 5 ; 1968 

Ore: 689; R1S; 0.23 percent Nb20 5 ; 1968 

Ore: 3,262; R1S; 0.67 percent Nb20 5 , 0.032 percent U30 8 ; 1973 

29 

Comments 

Future startup dependent on viability of several commodities. 

The resources reported are a 

mixture of various resource 

categories within the U.N. 

classification. 

Deposit has 230 m of unconsolidated cover. 

Substantial apatite and anatase 

resources occur at this deposit. 

Ore is residual capping on carbonatite. The carbonatite is not 

ore. 

Uranian pyrochlore is concentrated in steeply dipping shoots 

6 to 18m wide. 
TABLE 9. -Selected production and mineral-resource information 

Site name Year of Year of first Mining Elements and minerals Annual production (in 1,000 t) discovery production method of economic interest 

CANADA-Continued 

Martison Lake (Ontario) 1980 None N Nb,P 

Nemegosenda (Ontario) 1956 None N Nb, U, Th, REE, Zr, 

P, Fe. 

Niobec (St. Honore) 1969 1976 u Nb,REE,P Ore: 762; 0.66 percent Nb20 5 ; 1987 

(Quebec). 

Oka district (Quebec) 1956 1961 s. u Nb 

St. Andre (Quebec) 1969 None N Nb 

Strange Lake 1980 None N Nb, Zr, Y, Be, REE 

(Newfoundland). 

Thor Lake (Northwest 1979 None N Nb, Ta, Zr, Y, Be 

Territories). 

CHINA 

Bayan Obo (Inner 1957 (Fe, s Fe, REE, Nb Ore: 7 ,000; Fe ore; 1987; Est 

Mongolia). REE). REE cone: 15; REE; 1987; Est 

GREENLAND 

Sarfartoq (West Greenland) None N Nb,REE, U,P 

KENYA 

MrimaHill 1934 None N Nb, Th, Ba, Ta, Ti, 

P. 

TANZANIA 

Panda Hill (Mbeya) 1950 None N Nb, REE, U, Th, Ti, 

Ta. 

UGANDA 

Sukulu Hills (Buganda) 1939 1964 s Nb,P 

UNITED STATES 

Bear Valley placers 1950 1954 N Nb, U, Ta, Ti, Zr, Ore: 23; estimated capacity only. Some production 

(Idaho). REE. (possibly from stockpile) until 1959. 

Gem Park Complex 1880 N Nb, REE, Th, U, Sr, Ore: 3; estimated capacity only 

(Colorado). P, Ba, Mo. 

McClure Mountain 1963 N Th, Nb, U, REE 

Complex (Colorado). 

Powder Hom/Iron Hill 1880 N Nb, U, Th, REE, P, 

deposit (Colorado). Ba, Ta, Ti, mica. 

30 
from ISM/ records for niobium and tantalum deposits and districts-Continued 

Cumulative production 

(in 1,000 t) 

Cone; 52; (1961-68) 

Cone; 10; 0.306 percent 

Nb205; (1961-70). 

Resources (in 1 ,000 t) 

CANADA-Continued 

Ore: 140,000; R1S; 0.35 percent Nb20 5 , 20 percent P20 5 ; 1983 

Ore: 57 ,000; R1S; 0.4 percent Nb20 5 , 23 percent P20 5 , 0.4 percent REO; 

1984. 

Ore: 18,144; R1S; 0.47 percent Nb20 5 ; 1956 

Ore: 12,260; R1E; 0.656 percent Nb20 5 ; 1988 

Ore: 23,193; R1M; 0.44 percent Nb20 5 ; 1974 

Ore: 15,785; R1S; 0.3-0.4 percent Nb20 5 

Ore: 96,620; R1S; 0.26 percent Nb20 5 

Ore: 20,412; R1S; 0.4-0.5 percent Nb20 5 , 0.2-0.5 percent REO, 0.06 percent 

Th02. 

Ore: 27,216; R1S; 0.6 percent Nb20 5 

Ore: 22,680; R1S; 0.35 percent Nb20 5 

Ore: 3,447; R1S; 0.31 percent Nb20 5 , 0.5 percent REO 

No data published 

Ore: 52,000; R1S; 0.56 percent Nb, 3.25 percent Zr02 , 0.66 percent Y20 3 , 

1.3 percent REE, 0.12 percent BeO; 1981. 

Ore: 62,500; R1S; 0.57 percent Nb20 5 , 0.04 percent Ta20 5 , 1.99 percent 

REO, 4.73 percent Zr02 ; 1987. 

CIDNA-Continued 

Ore: 770,000; R1M; 0.13 percent Nb; 1990 

Ore: 2::: 800,000; RlE; 6 percent REE; 1990 

Ore: 2::: 4,300,000; R1E; 35 percent Fe; 1990 

GREENLAND-Continued 

KENYA-Continued 

Ore; 51,000; 0.67 percent Nb20 5 

TANZANIA -Continued 

Ore; 67 ,500; 0.3 percent Nb20 5 

UGANDA-Continued 

Ore; 130,000; 0.2-0.25 percent Nb20 5 

UNITED STATES-Continued 

No data published 

No data published 

No data published 

Ore: 655,622; R1E; 0.0041 Th02, 0.00127 percent U30 8 , 0.3965 percent 

REO, 0.057 percent Nb20 5 ; 1979. 

Ore: 2,423,998; R2E; 0.0041 Th02, 0.00127 percent U30 8 , 0.3965 percent 

REO, 0.057 percent Nb20 5 ; 1979. 

31 

Comments 

Ceased production 1976. 

Nb is not produced but is 

present in the slag from iron 

smelting. 

Concentrations of REE, U, Nb, 

and P occur in amounts that 

may attract economic interest. 

Production ceased in 1959. 

REE and niobium grades are 

low, but thorium is abundant 

in vein-type deposits. 
Site name 

Bingo (Upper Zaire) 

Lueshe (Kivu) 

TABLE 9. -Selected production and mineral-resource information 

Year of Year of first Mining Elements and minerals 

discovery production method of economic interest 

1958 

1938 

N 

N 

Nb 

Nb 

ZAIRE 

Annual production (in 1 ,000 t) 

Part B. -Principal tantalum mines and deposits 

Site name 

Greenbushes (Western 

Australia). 

Bernie Lake (Manitoba) 

Alto Ligonha (Zambezia) 

Year of 

discovery 

1888 

1928 

(for 

Srt). 

Year of first Mining 

production method 

1944 (for s 

Ta). 

1969 u 

s 

Elements and minerals 

of economic interest 

AUSTRALIA 

Sn, Ta, Nb, Li 

CANADA 

Annual production (in 1,000 t) 

Ore: 1,500; 0.027 percent T~0 ; 1985-86; Ace 

Ore: 1,270; 0.027 percent Ta20 5 ; 1986-87; Ace 

Ore: 1,630; 0.057 percent Ta20 5 ; 1987-88; Ace 

Ta, Li, Cs, Be, Ga, T~05 in cone: 0.125; grade not available; 1981; Est 

Nb, Rb, quartz, Sn, 

feldspar, Ti, Mn. 

MOZAMBIQUE 

Ta, Nb 

32 
from ISM/ records for niobium and tantalum deposits and districts-Continued 

Cumulative production 

(in 1,000 t) Resources (in l ,000 t) 

Ore; 4,800; 2.3 percent Nb20 5 

Ore; 34,500; 1.02 percent Nb20 5 

ZAIRE-Continued 

Part B.-Principal tantalum mines and deposits-Continued 

Cumulative production 

(in 1,000 t) 

Tantalite cone: 1.241; 

(until 1975); Ace. 

T~0 : 0. 712; 

(1976-87); Ace. 

Resources (in 1,000 t) 

AUSTRALIA-Continued 

Soft rock: 7 ,280; R1E; 0.26 kg/t Sn, 0.07 kg/t T~0 , 0.03 kg/t ~0 ; 1988 

Tailings: 8,950; R1E; 0.06 kg/t Sn, 0.045 kg/t T~0 , 0.03 kg/t Nb20 5; 1988 

Hard rock: 13,460; R1E; 1.50 kg/t Sn, 0.060 kg/t T~0 , 0.40 kg/t Nb20 5 ; 

1988. 

CANADA-Continued 

Ta cone: 1.7;(1969-87); Ore: 1,879; R1E; 0.216 percent T~0 ; 1979 

Ace. Ore: 981; R1E; 0.138 percent T~0 ; 1983 

Tailings: 637; R1E; 0.065 percent T~0 ; 1983 

MOZAMBIQUE-Continued 

33 

Comments 

Comments 

Production was suspended in 

1982 and re-started in 1988. 

Believed to have begun production in about 1988. 
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INTERNATIONAL STRATEGIC MINERALS INVENTORY 

PARTICIPATING AGENCIES 

Australia 

Bureau of Resource Sciences 

Canada 

Energy, Mines & Resources Canada 

Mineral Policy Sector 

Geological Survey of Canada 

Federal Republic of Germany 

Bundesanstalt fiir Geowissenschaften 

und Rohstoffe 

Republic of South Africa 

Minerals Bureau 

Geological Survey 

United Kingdom 

British Geological Survey 

United States 

Bureau of Mines 

Geological Survey 

SUMMARY REPORTS 

This circular is one of several reports on selected mineral commodities to be published 

in the U.S. Geological Survey 930 series. The circulars published to date are listed below; 

year of publication is shown in parentheses. Copies are available free on application to the 

U.S. Geological Survey, Map Distribution, Box 25286, Bldg. 810, Federal Center, Denver, 

CO 80225 U.S.A. 

930-A. Manganese (1984) 

930-B. Chromium (1984) 

930-C. Phosphate (1984) 

930-D. Nickel (1985) 

930-E. Platinum-Group Metals (1986) 

930-F. Cobalt (1987) 

930-G. Titanium (1988) 

930-H. Graphite (1988) 

930-1. Lithium (1990) 

930-J. Tin (1990) 

930-K. Vanadium (1992) 

930-L. Zirconium (1992) 

930-M. Niobium (Columbium) and 

Tantalum (1993) 

Requests for copies of International Strategic Minerals Inventory summary reports and for further information may 

also be addressed to: 

Gordon C. Battey, Director 

Mineral Resource Branch 

Bureau of Resource Sciences 

John Curtin House 

22 Brisbane A venue 

Barton, ACT 2600 

AUSTRALIA 

Mineral Policy Sector 

Energy, Mines & Resources Canada 

460 O'Connor Street-Room 908 

Ottawa, Ontario, KIA OE4 

CANADA 

Distribution Branch 

Bundesanstalt fiir Geowissenschaften 

und Rohstoffe 

Postfach 51 01 53 

D-3000 Hannover 51 

FEDERAL REPUBLIC OF GERMANY 

Chief Director, Minerals Bureau 

Private Bag X4 

Braamfontein 2017 

REPUBLIC OF SOUTH AFRICA 

Gregory R. Chapman 

British Geological Survey 

Keyworth 

Nottingham NG12 5GG 

UNITED KINGDOM