96 



UNITED STATES MINERAL RESOURCES 



devices. Experimental uses and some laboratory 

 reagent chemicals account for small additional quan- 

 tities (Bancel, 1971). 



The future for bismuth seems good. However, 

 much of the demand for bismuth depends somevi^hat 

 on the state of health of the aircraft and automobile 

 industries. These affect lead production, and in- 

 creased lead production should normally increase 

 bismuth production. 



The search for new and undiscovered sources of 

 bismuth will correspond to the search for bismuth's 

 associated metals, such as cobalt, copper, gold, lead, 

 molybdenum, silver, tin, tungsten, and zinc. Ash 

 from some coals contains as much as 0.003 percent 

 bismuth, or 30 ppm (Goldschmidt, 1935). 



Estimated annual production of bismuth in the 

 United States ranged from 590,000 pounds in 1962 

 to approximately 850,000 pounds in 1971. These 

 figures probably include some bismuth produced in 

 the United States from foreign ores. The United 

 States consumed from 2,175,038 to 3,199,321 pounds 

 of bismuth metal annually during 1963-70 ; in 1971, 

 consumption dropped to 1,648,718 pounds. World 

 bismuth production in 1971 (excluding People's Re- 

 public of China and U.S.S.R.) totaled 7,990,000 

 pounds (Cook, 1972). 



U.S. bismuth demand is forecast to increase at an 

 annual rate of 3 percent, and the domestic consump- 

 tion in the year 2000 is estimated to range from 3 

 to 5.2 million pounds (Charlie Wyche, oral commun., 

 1972). Though the supply of bismuth seems assured, 

 exploration cutbacks, production problems (such as 

 strikes, continued smelter closings, or mine fires), 

 or nationalization of foreign mines may result in a 

 reduction of much-needed imports as well as domes- 

 tic production. The bismuth supply situation could 

 then become most critical. 



EXPLOITATION 



Bismuth, a metallic element, was probably un- 

 known to the Greeks and Romans; in the Middle 

 Ages it became familiar but was frequently con- 

 fused with other metals, such as tin, lead, antimony, 

 and zinc. In the 15th century Basil Valentine re- 

 ferred to it as "wismit." About 1597, the eflScacy of 

 bismuth nitrate in treating intestinal disorders was 

 discovered by Andreas Lebanius, and the element 

 has been used for that purpose to the present. How- 

 ever, it was not until the 18th century that J. H. 

 Pott, C. J. Geoffrey, and T. Bergman produced pure 

 bismuth metal. Beginning in 1833 with the Patti- 

 son process for desilverization of lead bullion and 

 attendant extraction of bismuth alloy, continued 

 development and improvement of metallurgical 



processes for extraction and purification of bismuth 

 have resulted in commercial availability of bismuth 

 metal of 97.995 percent purity. 



Bismuth compounds were noted initially for their 

 soothing effects on human digestive disorders and 

 healing effects on wounds and sores. This property 

 of bismuth was exploited in many medicinal and 

 cosmetic preparations, and until 1930 some 90 per- 

 cent of the bismuth used was for this purpose. The 

 development of low-melting alloys has since resulted 

 in a wide variety of industrial applications of bis- 

 muth alloys and chemical compounds such as metal- 

 lurgical additives for aluminum, carbon steel, and 

 malleable iron and in pearlescent pigments. The 

 major current uses for metallic bismuth depend on 

 its ability to impart fusibility and machinability to 

 a variety of alloys. The United States consumes con- 

 siderably more bismuth than is recovered from 

 domestic ores and must therefore rely on imports 

 for 50-75 percent of its supply (Persse, 1970). 

 Major sources of imports in 1971 were Mexico, 

 Japan, and Peru. Refinery production of bismuth in 

 the United States is mainly from the American 

 Smelting and Refining Co. in Omaha, Nebr. ; U.S. 

 Smelting, Refining, and Mining Co. at East Chicago, 

 Ind. ; and Southern California Chemical Co., Los 

 Nietos, Calif. 



Reductions in lead production and subsequent 

 closures of any lead refining facilities will seriously 

 affect the bismuth supply in the United States. Cur- 

 rent environmental problems are having a serious 

 impact on the domestic mining industry and will 

 continue until such problems can be solved. 



GEOLOGIC ENVIRONMENT 



GEOCHEMISTRY 



The average bismuth content of the earth's crust 

 is estimated at 0.1 ppm or one part in 10 million. 

 Bismuth's abundance is reported to be highest in 

 oceanic manganese nodules, where it ranges from 

 0.5 to 24 ppm, and is next highest in silicic rocks, 

 in which it ranges from 0.02 to 0.9 ppm (Michael 

 Fleischer, written commun., 1970). Analyses from 

 various sources indicate that the abundance of bis- 

 muth in coal ash may be as much as 0.003 percent, 

 or 30 ppm (Goldschmidt, 1935). 



Bismuth, like arsenic and antimony, is chalcophile, 

 and all three show a strong affinity for sulfur. Most 

 bismuth-bearing minerals crystallize in late mag- 

 matic stages or are deposited by relatively hot hydro- 

 thermal solutions. Throughout the geochemical cycle, 

 bismuth is comparatively readily precipitated as 

 basic carbonate which forms during the hydrolytic 

 decomposition of bismuth salts in aqueous solution. 



