METHOD FOR EXTRACTION OF COBALT Russian patent published in 1997 - IPC

FIELD: metallurgy, particularly, hydrometallurgical process of extraction of cobalt. SUBSTANCE: roasting of cobalt hydroxide is carried out to prepare cobalt oxide. Thus prepared cobalt oxide is then cooled and dissolved in sulfuric acid to prepare solution of cobalt sulfate, said dissolution takes place in the presence of reduction agent. Then purification of solution against impurities, evaporation of said solution, crystallization of cobalt sulfate as crystallohydrate and drying of salt take places. Mentioned above roasting of cobalt hydroxide is carried out at 800-940 C. Cooling thus prepared oxide takes place by discharging it into water. Dissolution in sulfuric acid takes place in the presence of hydrazine hydrate, its quantity being 0.05-1 % of mass of cobalt oxide, the process takes place till final pH is 3.1-4.0. EFFECT: improved efficiency of the method. 3 tbl