UNITED STATES MINERAL RESOURCES 



COBALT 



By John S. Vhay, Donald A. Brobst, and Allen V. Heyl 



CONTENTS 



Page 



Abstract of conclusions 143 



Introduction . 143 



Exploitation 144 



Geologic environment 145 



Geochemistry 145 



Cobalt minerals 146 



Types of deposits 146 



Hypogene deposits associated with mafic in- 

 trusive igneous rocks 146 



Contact metamorphic deposits 147 



Lateritic deposits 148 



Massive sulfide deposits in metamorphic rocks 148 



Hydrothermal deposits 149 



Strata-bound deposits 150 



Chemical 'precipitates 150 



Resources 150 



Identified resources 150 



Hypothetical resources 151 



Speculative resources 152 



Prospecting techniques 152 



Problems for research 153 



Eeferences cited 153 



TABLES 



29. 

 30. 

 31. 

 32. 



33. 



Page 



World production of cobalt in 1969 144 



Average cobalt content of igneous rocks 145 



Cobalt minerals 146 



Identified resources of cobalt in the United 



States 150 



Identified resources of cobalt in the world 151 



ABSTRACT OF CONCLUSIONS 



Cobalt is a hard, silvery white metal of strategic import- 

 ance in the production of high-temperature alloys, perma- 

 nent magnets, and tool steels. Currently the United States 

 ■onsumes about 15 million pounds of the world's annual 

 cobalt production of 45 million pounds, but the domestic 

 production, only about 3 million pounds, is derived from 

 recycled scrap and the byproduct of iron mining in Penn- 



sylvania. That the amount of cobalt mined annually in the 

 United States is so small is more a function of economic and 

 technological problems than the lack of ore deposits contain- 

 ing cobalt. Nearly all the cobalt that now reaches the world 

 markets is the byproduct of mining sulfide ores of associated 

 metals, chiefly copper, nickel, and iron in central Africa, 

 Canada, and Finland. Large potential supplies of cobalt are 

 in lateritic iron-nickel deposits of tropical regions. More 

 than 1 billion pounds of cobalt is in the identified resources 

 of the United States, chiefly in various types of deposits of 

 sulfide ore in the Appalachian and midcontinent regions. Pub- 

 lished data indicate that the identified cobalt resources of the 

 world contain more than 9.9 billion pounds of the element. 

 Additional large amounts of cobalt are in the manganese 

 nodules of the sea floor. The world's hypothetical and specu- 

 lative resources of cobalt likely amount to many more bil- 

 lions of pounds of metal. 



INTRODUCTION 



Cobalt (Co) is a hard, moderately malleable and 

 ductile, strongly magnetic, silvery, white metal of 

 great commercial importance in metallurgical appli- 

 cations. The major uses of cobalt in the United States 

 are, in order of consumption : ( 1 ) high-temperature 

 alloys, the superalloys, (2) permanent-magnet al- 

 loys, (3) cutting and wear-resistant alloys, (4) tool 

 steels, (5) miscellaneous alloys, (6) pigments and 

 driers for paint, ink, lacquer, and varnish, (7) 

 ground-coat frit for enameling, (8) catalysts in the 

 chemical and petroleum industries, (9) ceramic 

 glazes, (10) additives and supplements to sheep and 

 cattle feed, and (11) as radioactive Co^° in several 

 medical applications. 



In 1969 the United States consumed about 15 mil- 

 lion pounds of the world's estimated production of 

 45 million pounds of cobalt (table 29). Domestic 

 sources provided only about 3 million pounds, de- 

 rived from recycled scrap and as a moderate-yield 

 byproduct from iron mines in southeastern Pennsyl- 

 vania (DeHuff, 1971, p. 399). The remaining domes- 

 tic needs of 12 million pounds were filled by imports 

 from ores originating chiefly in Zaire, Canada, 

 Morocco, and Zambia. 



U.S. GEOL. SURVEY PROF. PAPER 820 



143 



