UNITED STATES MINERAL RESOURCES 



GRAPHITE 



By Paul L. Weis 



CONTENTS 



Page 



Abstract of conclusions 277 



Introduction 277 



Exploitation 279 



Geologic environment 280 



Geochemistry 280 



Geology 280 



Vein graphite 280 



Flake graphite 280 



Amorphous graphite 281 



Resources 281 



Identified and hypothetical resources 281 



Speculative resources 282 



Prospecting 282 



Problems for research 282 



Selected references 283 



FIGURE 



31. Graph shovidng U.S. consumption of graphite, 



1910-69 279 



TABLES 



Page 



52. Consumption, by uses, of natural graphite in 



the United States in 1969 278 



53. Tonnage and value of 1969 U.S. imports for 



consumption of natural graphite, by coun- 

 tries 278 



54. Identified resources of graphite of the United 



States 281 



55. Identified and hypothetical graphite resources 



of the world 282 



ABSTRACT OF CONCLUSIONS 



Within the last 20 years technology and attitudes in the 

 graphite industry have changed significantly. In 1950 the 

 domestic industry demanded natural graphite from only a 



few sources and strongly resisted substitutions. Since 1960, 

 the price of raw graphite has risen because of steadily in- 

 creasing costs of labor at the source areas abroad and the 

 more recent devaluation of the dollar in the world market. 

 Today, new technology has shown that these old preferences 

 need not be so rigorously applied. Domestic consumption of 

 generally more costly synthetic graphite has increased and 

 by 1969 was seven times that of natural graphite. 



This combination of technical and economic factors has 

 generated renewed interest in domestic graphite deposits 

 whose total resources are greater than 10 million tons. Ex- 

 cept for one active mine in Texas, no domestic resources of 

 graphite currently seem competitive with foreign sources. 

 Flake graphite deposits in Alabama, New York, and Penn- 

 sylvania are probably too low grade to mine now. Flake 

 and amorphous deposits in Alaska are too remote, and vein 

 deposits in Montana are too small to be of commercial value 

 soon. 



The likelihood of finding richer, larger, or more favorably 

 located domestic deposits seems slight. 



INTRODUCTION 



The graphite industry is one of the Nation's 

 smallest mineral industries. The total sales of natu- 

 ral graphite in the domestic industry were less than 

 $61/2 million in 1969; however, the unique physical 

 and chemical properties of graphite make it irre- 

 placeable in some uses. The importance of graphite 

 to the national economy is therefore difficult to de- 

 fine precisely, but is far greater than the annual 

 dollar value of commercial sales would appear to 

 indicate. 



Graphite is pure crystalline carbon ; it is steel gray 

 and has a hardness of 1 to 2, specific gravity of 2.1 

 to 2.3, and excellent cleavage. It is sectile, flexible, 

 and a good conductor of heat and electricity. Graph- 

 ite is also extremely inert to most chemical reagents, 

 including hydrofluoric acid and boiling aqua regia. 

 At temperatures above 600 °G graphite decomposes 

 slowly in an oxidizing atmosphere, but if protected 

 by a nonoxidizing atmosphere or an inert coating, it 

 remains stable to 3,500°C. 



U.S. GEOL. SURVEY PROF. PAPER 820 



277 



