TRIM 

(Hamilton and Takahashi, 1996), users are 

able, every 18 months, to purchase computers 

that are twice as powerful at the same price as 

those currently available (Jung, 1999). This 

cyclic trend (with its inherent surplus of old 

computer components) has been sustained for 

nearly 20 years of recent computer history. To 

meet consumer demand, the computer and 

electronics industry has become the largest 

manufacturing employer in the United States, 

representing 11 percent of the gross domestic 

product and growing at an annual rate of 4 

percent (Porter, 1998). 

The quantities and types of materials used in 

computer products to meet this demand are 

great and varied, as is the potential to recover 

these computers and their materials for reuse, 

remanufacturing, and recycling. In 1998, 

nearly 43 million new PC’s and notebook 

computers were purchased by consumers in 

the United States; and it is estimated that in 

the year 2003, nearly 70 million computers 

will be purchased by consumers in the United 

States (National Safety Council, 1999). 

In 1997, it was estimated that between 1985 

and 2005, approximately 325 million PC’s 

would become obsolete in the United States 

(Jung, 1999). In a business environment, the 

useful life of a PC is about 2 years, while in 

homes PC’s are used from 3 to 5 years (Jung, 

1999). Between 14 and 20 million PC’s 

1Based on 1 troy ounce of gold recovered for every 3 t of 

electronic scrap (10.4 grams per metric ton (g/t)) and an 

average gold ore feed grade of 0.9 g/t for a typical gold 

openpit cyanide leaching operation in Nevada with an 

overall 67 percent gold recovery. 

2Based on a 2.7:1 waste-to-ore ratio. 

U.S. Department of the Interior

U.S. Geological Survey 

Figure 1. Circuit boards are sought after by recyclers for their metals content, especia

and silver. Photograph courtesy of Melissa Goodrich, Recycling Today. 

Plastic manufacturers 

Waste to energy 

Hazardous 

waste landfi

Hazardous 

waste 

Nonhazardous 

waste Municipal 

waste landfil

Donation 

recipients 

Obsolete computers 

Obsolete computers in storage 

CRT manufacturers 

Smelters 

Remanufacturing 

Glass 

Metals, glass, and mixed plastics 

Separated plastics 

Mixed plastics 

Reusable parts and 

refurbished computers 

Recycling 

activities 

consisting 

of collection 

and 

separation 

become obsolete every year in the United 

States. About 75 percent of these obsolete 

computers are not discarded because their 

owners perceive them to be valuable 

(Goodrich, 1999); a portion of these will not 

be recycled. For every three computers
 

purchased in the United States, two will be
 

taken out of service, and this ratio is expected 

to increase to 1:1 by 2005. It is projected that
 

by 2005, a total of 680 million PC’s will have 

been sold worldwide. Of that total, it is 

estimated that 150 million computers will be 

recycled that year and 55 million c

will end up in landfills alo

unreclaimed portions of the 150 

recycled computers (Hamilton and T

1996).
 

Recycling Flow
 

Figure 2 is a generalized mate

diagram that shows what happens t

PC’s and their components. 
 

Figure 2. A generalized materials flow diagram illustrating what happens to obsolete 

their components. 

USGS Fact Sheet 
TRIM 

gp

in their business; and the rest from small 

companies, government offices, and 

individuals (National Safety Council, 1999). 

Some scrap is unwanted because of low 

precious metal content and the potentially 

hazardous nature of some of its materials. For 

example, the presence of lead in some 

electronic scrap prevents it from being placed 

in a municipal landfill. Some refiners actually 

have to charge as much as $1 per pound to 

process the scrap because of these deleterious 

materials (Broughton, 1996). 

Some scrap was exported to Taiwan for 

open burning and chemical processing; 

however, the Taiwanese government had 

reportedly become increasingly concerned 

about the environmental damage caused by 

this practice (Broughton, 1996). Chinese and 

other Asian consumers pay 15 to 20 cents per 

pound for electronic scrap on the U.S. West 

Coast (Goodrich, 1999). Environmental 

regulations are less strict (or not enforced), 

and labor costs are much lower in some of 

these countries. 

Metals 

The metals contained in PC’s commonly 

include aluminum, antimony, arsenic, 

barium, beryllium, cadmium, chromium, 

cobalt, copper, gallium, gold, iron, lead, 

manganese, mercury, palladium, platinum, 

selenium, silver, and zinc. Eight of these 

metals (shown in bolded type) are listed as 

hazardous by the Resource Conservation and 

Recovery Act (RCRA), one of the Federal 

laws that control the disposition of waste in 

the United States. This law prohibits 

g

arsenic, mercury, and, espec

electronics recycling industry. However, in an These elements can contribut

effort to cut costs, manufacturers have harmful atmospheric emissions 

gradually reduced the precious metal content Noranda, Inc., oral commun., 20

in electronic products, and this trend is likely result in additional costs for 

to continue (Porter, 1998). Information on the 


specific amounts of individual precious
 disposal. Military electronic s

metals (gold, silver, and the platinum group computer circuit boards, recei

metals) recovered is unavailable, but as much former Soviet Union (Nadea

as one-third of the precious metals recovered especially sought for recyclin

from scrap may be gold (Sean Magaan, their comparatively high pr

Noranda, Inc., Micro Metallics Corp., oral content. The scrap can contain 

commun., 1999). The value of the 1 t of amount of precious metals tha

precious metals recovered from electronic and significantly higher amoun

scrap in the United States in 1998 (table 1) metals as electronic compone

probably exceeded $3.6 million. This value elsewhere.
 

was obtained by assuming that the precious
 

metals recovered consisted of 60 percent In the mid-1980’s, one of 

silver and 40 percent gold, palladium, and largest mining companies, N

platinum. The average price used to calculate (Noranda) of Canada, investig

the value was $5.10 per troy ounce of silver make their smelters more 

and an average of $300 per troy ounce of Feasibility studies and testing d

gold, palladium, and platinum. Several U.S. “mining” computer and other el

companies reported producing more than would bring a welcome supplem

1,500 troy ounces per year of precious metals and precious metals to the

from electronic scrap (Dawn Amore, National Noranda’s findings indicat

Recycling Coalition, oral commun., 1999). concentration of some metal

Circuit boards and batteries contain most of computer and other electronic 

more than twice that found in or

the heavy metals, and circuit boards contain 

the highest precious metal values. One metric 

ton of circuit boards can contain between 80 So in 1984, Noranda bega

and 1,500 g of gold and between 160 and 210 small amounts of scrap (Reid, 

kg of copper (Veldhuizen and Sippel, 1994). 1999, was the largest electron

This is 40 to 800 times the concentration of plant in North America, receivi

gold contained in gold ore mined in the 50,000 t/yr of electronic scrap 

United States and 30 to 40 times the 400 suppliers in 18 countries (N

concentration of copper contained in copper Reid, 1999). Recyclable m

ore mined in the United States. Gold in an considered to be an import

obsolete computer has little or no value. Like Noranda’s smelters, as esse

ore, it must be collected, concentrated, and concentrates are to the 

refined in order to acquire a high value. profitability (Rob Bouma, N
devices, melted down for use as raw materials 

for new products, or used as fuel. More than 

6,500 t of plastic were reportedly recovered 

from U.S. electronics recyclers in 1998, an 

increase of nearly 25 percent over 1997 

(National Safety Council, 1999). When used 

as a fuel for cement kilns in the smelting 

process, 1 t of plastic can replace nearly 1.3 t 

of coal (National Safety Council, 1999). The 

plastic components are consumed at a very 

high temperature and when mixed with 

oxygen-enriched air aids the combustion 

process. Using plastic in this way conserves 

space in landfills and decreases the use of 

coal. However, truly effective recycling of 

plastics from computers is hampered by two 

things: the variety of plastics used and a lack 

of labeling. Mixtures of recovered plastic 

have little value; however, if the plastics are 

cleaned and separated, prices can range from 

$265/t for flaked polypropylene to $900/t for 

pelletized ABS (acrylonitrile-butadienestyrene). 

Glass 

Glass, primarily from cathode ray tube 

(CRT) monitors, represented about 25 percent 

of the total weight of material produced by 

electronics recyclers in 1998, or about 13,200 t 

(National Safety Council, 1999). Because of 

its lead content, glass is classified as 

Figure 3. Obsolete computers and monitors, which could be donated, recycled, or 

remanufactured, accumulate in office storerooms. 

hazardous waste, and it must be handled, 

processed, and disposed of in a manner 

consistent with federally mandated guidelines. 

In 1998, nearly 1.8 million monitors were 

collected in the United States for recycling or 

remanufacturing (fig. 3), about 60 percent of 

which were exported for this purpose 

(National Safety Council, 1999). Broken 

glass from monitors is purchased by several 

companies for the production of new CRT’s. 

Noranda recycles more than 1,000 t of 

monitors, CRT’s, and broken glass from 

CRT’s per year (Rob Bouma, Noranda, Inc., 

oral commun., 1999). Whole monitors are fed 

to the company’s copper smelter in Quebec. 

These monitors may contain between 4 and 7 

percent copper, between 5 and 10 percent 

lead, approximately 30 percent silica (the 

chief component of the glass in CRT’s), in 

addition to other material (primarily plastic 

from the plastic casings). 

CRT’s also are recycled. They have 

between 10 and 13 percent copper, between 

15 and 20 percent lead, and between 50 and 

60 percent silica. The copper is recovered and 

converted into a saleable metal at Noranda’s 

metallurgical facilities in Quebec. The silica 

contained in the glass CRT’s has value 

because silica is required as a fluxing agent in 

the metals separation process. The silica 

ultimately combines with slag, an iron-silicate 

waste product. The lead in the glass is not 

currently recovered and also is contained in 

the slag. Because the slag is highly inert and 

stable, it does not leach lead (Rob Bouma, 

Noranda, Inc., oral commun., 2000). The 

silica recovered from the glass CRT’s 

replaces purchases of equivalent amounts of 

silica. 

Clean CRT glass (crushed/broken with the 

steel and plastic removed) is sent to 

Noranda’s lead smelter in New Brunswick. 

The facility treats about 200,000 t of lead ore 

concentrates annually. A large percentage of 

the lead contained in the glass is recovered, 

and the silica is consumed in the process as a 

fluxing agent (Rob Bouma, Noranda, Inc., 

oral commun., 1999). 

In Canada, if the monitors or CRT’s are 

shredded or broken, they are classified as 

hazardous waste. As such, this material must 

have formal import approval from the 

Canadian Government and must be shipped 

under a Canadian Federal waste manifest. 
qy, 

energy is consumed, the amount of potentially 

toxic material destined for landfills is 

reduced, and there is less disruption to the 

environment. The reuse of components and 

refurbishment of computers lengthens their 

life spans and, when part of donation 

programs, provides inexpensive learning tools 

for students. 

Currently, the most effective way to recycle 

computers is through manufacturers, such as 

Hewlett-Packard. Most businesses, however, 

must arrange to have their discarded 

computers handled by electronics recycling 

firms and (or) hazardous waste facilities. 

Computer monitors and other computer 

components, such as lithium batteries, are 

separated out by the electronics recycling 

businesses, are usually considered to be 

hazardous waste, and, as a result, cannot be 

placed in municipal landfills. Therefore, 

computer recyclers in the United States are 

typically classified as hazardous waste 

handlers. A number of hazardous waste 

regulations apply to computer recyclers, 

which significantly increase operating costs 

and the overall costs of recycling (Jung, 

1999). Additionally, as PC technology 

continues to evolve, the amount of precious 

plastics, and eliminating toxic materials 

wherever possible. The Environmental Health 

Center, a division of the National Safety 

Council, provides information on obsolete 

computers, including a list of recyclers. It is 

available from the World Wide Web at 

http://www.nsc.org/ehc/epr2/donate.htm 

The Environmental Issues Council of the 

Electronic Industries Alliance has organized 

the Consumer Education Initiative to inform 

consumers about recycling and reuses of used 

electronics, including computers. An 

extensive list of recyclers, by State, is offered 

at their website. It is available from the World 

Wide Web at http://www.eiae.org/ 

References Cited 

Advanced Recovery, Electronic equipment 

recycling. (Accessed on the web on January 

5, 2000, at http://www.advancedrecovery. 

com/environmentalissues/html/electronic_ 

equipment_recycling.html) 

Amore, Dawn, 1999, Study finds computer 

recycling not clicking: Waste Age, v. 30, 

no. 12, p. 13–14. 

Broughton, Anne, 1996, Electronics 

recycling—Circuit board recycling 

Telephone: (303) 2368747, ext. 340
 

E-mail: bleiwas@usgs.gov
 

or 

Thomas Kelly
 

Telephone: (303) 236-8747, ext. 269
 

E-mail: kellyt@usgs.gov
 

U.S. Geological Survey, MS 750
 

Denver Federal Center, Box 25046
 

Denver, CO 80225
 

or visit the Minerals Information home page 

at http://minerals.usgs.gov/minerals 

or contact the Minerals Information Team at 

(703) 648-4911