STUDIES ON DIRECT REDUCTION OF CHROMIUM OXIDE BY SOLID CARBON IN A VACUUM.

Carbothermic reduction of chromium oxide to metallic chromium was carried out in a high vacuum of 1 multiplied by 10** minus **2 up to 10** minus **3 mm Hg at temperatures ranging from 1100 to 1400 C. At reaction temperatures below 1100 C, the predominant reactions involved chromium carbide formation. Metallic chromium almost cannot be detected in reaction product. At reaction temperature of 1200 to 1300 C, metallic chromium was formed by reduction of chromium oxide by chromium carbides. At reaction temperatures 1300 to 1400 C, vaporization rate of metallic chromium was higher than CO gas formation rate.