120 



UNITED STATES MINERAL RESOURCES 



PROBLEMS FOR RESEARCH 



The fundamental problem of chromium supply for 

 the United States is lack of domestic high-grade de- 

 posits and scarcity even of low-grade resources. 

 Endeavors to expand the domestic resource base 

 substantially would, it is believed, be very costly 

 (Brantley, 1970, p. 260). Without access to South 

 African, Rhodesian, and Russian sources, we would 

 have to be prepared to depend largely on low-grade 

 high-iron chromite ores from the Stillwater Com- 

 plex, from Canada, and from Greenland. This would 

 entail major shifts and inefficiencies in metallurgy 

 and for most other uses. 



Exploration for concealed podifoi-m chromite de- 

 posits in the United States faces major problems and 

 limitations. The first problem is the inability of 

 known geophysical and geochemical methods to point 

 to deposits concealed under very thin cover in areas 

 of even moderate relief. The limitations are twofold : 

 most podiform deposits are too small to be minable 

 even at moderate depths, and in aggregate the few 

 postulated relatively large deposits could only miti- 

 gate the national supply problem temporarily and at 

 very high cost. 



Research on means to recover more chromium 

 from scrap and from low-grade ores appears more 

 promising than geological research on domestic re- 

 sources. Stainless-steel scrap, other than mill scrap, 

 in 1968 provided the eqxiivalent of 51,000 tons of 

 chromium, or about 12 percent as much as was im- 

 ported in ore (Brantley, 1970, p. 252). Recovery of 

 chromium from scrap presumably will increase with 

 development of processes to dispose of solid waste in 

 general. 



Development of processes to smelt the higher 

 grades of Stillwater crude ore directly to FeCr alloy 

 with local energy would avoid losses of 15-20 percent 

 of contained CrsO., in milling (Thayer, 1962, p. 12) 

 and could greatly reduce transportation costs to 

 eastern consuming centers. Research aimed at adapt- 

 ing a process for direct smelting of high-iron chrom- 

 ite to stainless steel, announced in 1966 (Brantley, 

 1970, p. 261), to treat crude Stillwater ores, would 

 seem to be indicated. Though such a process cannot 

 compete with recovery of chromium from African 

 ores at present prices, increases in wages of African 

 miners to equitable scales and increased production 

 of FeCr in southern Africa for export could change 

 the situation drastically. Investigations of the Green- 

 land ores should consider the likelihood of separating 

 chromite readily from anorthosite by sink-float 

 methods, and recovery of the contained 0.3 percent 

 of V2O5 (Ghisler and Windley, 1967). 



REFERENCES CITED 



Balasundaram, M. S., 1972, A review of the reserves and 

 demand pattern of iron, manganese and chromite ores 

 in India: Eastern Metals Review, Ann. No., v. 25, p. 39- 

 49. 



Batty, J. v., Mitchell, T. F., Havens, R., and Wells, R. R., 

 1947, Beneficiation of chromite ores from the western 

 United States: U.S. Bur. Mines, Rept. Inv. R. I. 4079, 

 26 p. 



Berbert, C. 0., 1973, Geologia geral dos complexes basicos 

 e ultra-basicos de Goias : 24th Congresso Brasileiro de 

 Geologia, Soc. Brasileira de Geologia (in press). 



Brantley, F. E., 1970, Chromium, in Mineral facts and prob- 

 lems: U.S. Bur. Mines Bull. 650, p. 247-262. 



Cameron, E. N., and Desborough, G. A., 1969, Occurrence and 

 characteristics of chromite deposits — eastern Bushveld 

 Complex, 171 Wilson, H.D.B., ed., Magmatic ore deposits, 

 a symposium: Econ. Geol. Mon. 4, p. 23^0. 



Davies, J. F., 1958, Chromite deposits of southeastern Mani- 

 toba: Canadian Mining Jour., v. 79, p. 112-114. 



Flint, D. E., Guild, P. W., and de Albear, J. F., 1948, 

 Geology and chromite deposits of the Camagiiey Dis- 

 trict, Camagiiey, Province, Cuba: U.S. Geol. Survey 

 Bull. 954-B, p. 39-63. 



Ghisler, M., and Windley, B. F., 1967, The chromite deposits 

 of the Fiskenaesset region. West Greenland: Geol. Sur- 

 vey Greenland, Rept. 12, 39 p. 



Griggs, A. B., 1945, Chromite-bearing sands of the southern 

 part of the coast of Oregon: U.S. Geol. Survey Bull. 

 945-E, p. 113-150. 



Gross, G. A., 1970a, Nature and occurrence of iron ore de- 

 posits, in Survey of World iron ore resources, pt. 2: 

 New York, United Nations, p. 13-31. 



Gross, G. A., 1970b, Iron ore deposits of Canada and the 

 West Indies, in Survey of World iron ore resources, Pt. 

 3: New York, United Nations, p. 237-252. 



Hammer, S., Nettleton, L. L., and Hastings, W. K., 1945, 

 Gravimeter prospecting for chromite in Cuba: Geo- 

 physics, V. 10, p. 34-49. 



Jackson, E. D., 1961, Primary textures and mineral associa- 

 tions in the ultramafic zone of the Stillwater complex, 

 Montana: U.S. Geol. Survey Prof. Paper 358, 106 p. 



■ 1963, Chromium, in Mineral and water resources of 



Montana: U.S. Cong., 88th, 1st sess., Senate Comm. In- 

 terior and Insular Affairs, p. 57-60. Also reprinted as 

 Montana Bur. Mines and Geology Spec. Pub. 28. 



1968, The chromite deposits of the Stillwater Com- 



plex, Montana, in Ore deposits of the United States, 

 1933-1697 (Graton-Sales Volume), v. 2: New York, Am. 

 Inst. Mining, Metall. and Petroleum Engineers, p. 1495- 

 1510. 



Kahma, A., Siikarla, T., Veltheim, V., Vassjoki, O., and 

 Heikkinen, A., 1962, On the prospecting and geology of 

 the Kemi chromite deposit, Finland: Finlande Comm. 

 Geol. Bull. 194, 91 p. 



Kujanpaa, J., 1971, Maliesintyman geologia (Geology of 

 the Kemi ore deposit) : Vuorimieslehti-Bergshantering, 

 no. 2, 1971, p. 92-93 [translation in English by Outo- 

 kumpu Oy]. 



Materials Advisory Board, 1959, Report of the Committee 

 on Refractory Metals: Nat. Acad. Sci.-Nat. Research 

 Council, Rept. MAB-154-M (1), v. 2, chap. 4, p. 23^7. 



Mining Journal, 1972, Brazilian chromite development: Min- 

 ing Jour. (London) , v. 278, p. 93. 



