MERCURY 



403 



ploration or development over a hundred-year pe- 

 riod. To avoid high labor costs, in the past 30 years 

 a diligent search has been made in the United States 

 for large low-grade surficial deposits, but the only 

 really major deposit that has been mined by open- 

 pit methods is that of the Sulphur Bank mine also 

 in California, which was discovered 100 years ago. 



Mining and recovery costs at mercury mines vary 

 so widely that averages seriously oversimplify the 

 picture. At open-pit mines, ore containing 2 pounds 

 of mercury per ton ($5 per ton in 1963) has been 

 successfully treated, but concurrently some under- 

 ground mines have lost money on ore containing 10 

 pounds per ton. In 1970 the Quinn River mine (for- 

 merly Cordero) in Nevada closed when the price 

 fell below $425 a flask, and in 1972 the major New 

 Idria mine in California was closed when the price 

 fell below $160 a flask. For comparative purposes, 

 the best guides to costs are price-production curves 

 (fig. 46). At any given price, some mines lose 

 money, others break even, and only a few make a 

 profit. Average costs generally approach average 

 prices within a few percent. 



PRODUCTION 



Total world production during this century has 

 ranged from 65,000 flasks in 1933 to 290,000 flasks 

 in 1969 (fig. 46). Probably nearly 1,000 mines in 

 the world have each produced more than 100 flasks 

 of mercury, but three-fourths of the world produc- 

 tion has come from only six mines or districts. 



Domestic primary production fluctuates wildly in 

 response to short-term variations of a few hundred 

 percent in price. The peak U.S. production, almost 



80,000 flasks, was in 1877. Since then, the domestic 

 industry has undergone a half dozen cycles of stimu- 

 lated production, in response to higher prices, fol- 

 lowed by collapse, on the heels of lower prices. By 

 1943, under war-time conditions, production had 

 risen from the less than 10,000 flasks produced 10 

 years before to almost 52,000 flasks. By 1950, pro- 

 duction had again dropped, to a new low of 5,000 

 flasks. After another cycle, production rose in 1969 

 to 29,000 flasks in response to all-time high prices. 

 Our production through the years has come from 

 over 300 mines in 11 States (table 79) ; however, 

 just as is true for world production, three-fourths 

 of the domestic output has come from six mines, 

 all of which are in California. 



The U.S. proportion of world production, with 

 generally rising demand, has declined from more 

 than 60 percent in 1877 to less than 3 percent in 

 1950 and 6 percent in 1971. The proportion of U.S. 

 consumption coming from domestic mines reached 

 a low of 9 percent in 1950 but rose to 33 percent in 

 1971. This seeming improvement, however, is the 

 result of temporary curtailment of consumption be- 

 cause of pollution problems and does not reflect 

 increased production. 



Secondary production of mercury in the United 

 States, first reported in 1946, has become increas- 

 ingly important in helping to make up the diifer- 

 ence between U.S. requirements and mine produc- 

 tion. Most of the mercury reclaimed is from electro- 

 lytic cells, mercury boilers, discarded instruments, 

 battery scrap, dental amalgam, and electrolytic, 

 oxide, and acetate sludges. Secondary recovery is 

 made by six processors and four scrap dealers in 



Table 79. — Mercury produced in the United States, by States 



[Flaska of 76 lb] 



First 

 State production 1850-1949 1960-69 1960-69 1970 



Primary (from mines) : 



Alaska 1923 4,650 16.919 14.151 (>) 



Arizona 1908 6,034 819 1,439 



Arkansas 1931 11,404 350 (M 



California 1860 2,623,873 110,793 163,042 18,693 



Idaho 1917 14.731 14,268 7,927 1,038 



Nevada 1903 72,996 46,246 64,422 4,909 



New York 1969 280 28 



Oregon 1870'b 89,284 13,629 4,779 274 



Texas 1899 145,655 1,662 1,885 (') 



Utah Early 1880's 3,497 



Washington 1916 6,604 20 34 (>) 



Total primary 



Annual number of producing 



mines 



Annual averages of mercury 



recovered (lb per ton of ore) 



Secondary 1946 11,055 47,430 '94,469 »8,061 



' Alaska, Arkansas, Texas, and Washington, 2,454 flasks in 1970. 



' Alaska, Arkansas, New York, Oregon, and Texas, 1,748 flasks in 1971. 



•Includes GSA releases 1963-71. 



( = ) 

 13,233 

 1,067 

 1,589 

 (=) 

 ( = ) 

 (■) 



