US EPA

1514260 

Journal Article 

Mineral Facts and Problems 

Anonymous 

1970 

650 

250-253 

Chromium (7440473) occurs in nature only in a combined state. It is found in a large number of minerals, the only one of commercial importance being chromite (1308312). Current mining practices involve both open pit and underground methods, with the latter supplying the major part of the world's chromite ore. Techniques used in mining vary, with the more modern equipment found to a greater extent in the more developed countries which usually have higher labor costs. Chromite of metallurgical grade is converted into ferrochromium or other chromium additives and usually finds its way into special steels or alloys. Chromium metal is made either by electrochemical or pyrochemical methods. Research currently being conducted by industry on chromium concerns application of the metal and the ore to metallurgical, chemical, and refractory uses. Apparent reserves of chromite in the world are discussed. 

DCN-179040; Chromium VI; Metallic minerals; Heavy metals; Mining industry; Transition metals; Hexavalent chromium; Steelmaking industry; 7440-47-3; 1308-31-2