Ch. 3— Minerals Supply, Demand, and Future Trends • 99 



growth has been moderated largely by economic 

 conditions and, to a lesser extent, by reduction in 

 the intensity of copper use and substitution of other 

 materials. Thus, today there is the possibility of 

 substantial excess mine capacity in the world cop- 

 per industry. Overly optimistic forecasts of demand 

 based on consumption trends made in the late 1960s 

 and early 1970s, forecasts of higher real prices, and 

 the unforeseen onset of worldwide recessions be- 

 ginning in 1975 and 1981 contributed to excess cop- 

 per production. 



The U.S. Bureau of Mines forecasts that domes- 

 tic demand will increase to between 2.6 tons and 

 4.5 million tons by 2000, with probable demand 

 about 3.1 million tons of copper (table 3-8). U.S. 

 demand is forecast to increase at an annual rate 

 of approximately 1.9 percent, while the rest of the 

 world is expected to expand copper use at the higher 

 rate of 2.9 percent. 



The intensity of copper use fell by about one- 

 fourth between 1970 and 1980.^^ Reductions in use 

 were caused by the reduction in size of automo- 

 tive and consumer goods, changes in design to con- 

 serve materials or increase efficiency, and substi- 

 tutions of aluminum, plastics, and, to a lesser 

 extent, optical fibers. Although the decline in the 

 intensity of copper use is not expected to continue 

 at the 1970s' rate and even could be offset by gains 

 in other areas, the future of copper demand is un- 

 certain. Moreover, copper is an industrial metal, 

 and its consumption is linked to industrial activity 

 and capital expansion. This makes copper demand 

 very sensitive to general economic activity. 



Zinc 

 Properties and Uses 



Zinc is the third most widely used nonferrous 

 metal, exceeded only by aluminum and copper. It 

 is used for galvanizing (coating) steel, for many 

 zinc-based alloys, and for die castings. Zinc is also 

 used in industrial chemicals, agricultural chemicals, 

 rubber, and paint pigments. Construction mate- 

 rials account for about 45 percent of the slab zinc 

 consumed in the United States; transportation ac- 

 counts for 25 percent; machinery, 10 percent; elec- 

 trical, 10 percent; and other uses, 10 percent. 



National Importance 



During the last 15 to 20 years, the United States 

 has gone from near self-sufficiency in zinc metal 

 production to importing 74 percent of the zinc con- 

 sumed domestically in 1986.^^ Zinc is a component 

 of the National Defense Stockpile; the stockpile goal 

 is 1.4 million tons and the inventory in 1986 was 

 about 378,000 tons — 27 percent of the goal. 



The United States consumed about 1 . 1 million 

 tons of zinc in 1986. Between 1972 and 1982, U.S. 

 slab zinc consumption decreased by nearly half,^^ 

 a dramatic drop attributable to the combined ef- 

 fects of the economic recession and a decline in the 

 intensity of use of zinc in construction and manu- 

 facturing. 



Zinc is imported as both metal and concentrates. 

 Canada provides about half the zinc imported into 

 the United States; Mexico provides 10 percent; 

 Peru, 8 percent; and Australia, 4 percent. All of 



^''Domestic Consumption Trends; 1972-82, and Forecasts to 1993 

 for Twelve Major Metals, p. 60. 



^°J. Jolly, "Zinc," Mineral Commodity Summaries — i987 (Wash- 

 ington, DC: U.S. Bureau of Mines, 1987), p. 180. 



^''Domestic Consumption Trends, 1972-82, and Forecasts to 1993 

 for Twelve Major Metals, p. 131. 



Table 3-8.— U.S. and World Copper Demand in 2000 



2000 



A ctual Low Probable Hi£ 



(thousand tons) 

 2,390^ 2,600 3,100 3,9( 



8,300 11,700 13,400 15,0( 



— 14,300 16,500 18,8( 



^U.S. data for 1986, J. Jolly, and D. Edelstein, "Copper," Mineral Commodity Summaries— 1987 (Washington, DC: U.S. Bureau of Mines, 1987), p. 42, world data for 



1983 from source below. 

 SOURCE: Adapted from J. Jolly, "Copper," Mineral Facts and Problems— 1985 Edition (Wasfiington, DC: Bureau of Mines, 1986), p. 219. 



