Method for production of metallic cobalt from the nickel solvent extraction raffinate

Abstract

Method for production of metallic cobalt from the raffinate from solvent extraction of nickel'. Said method comprises the following stages: (A) obtaining the raffinate from solvent extraction of nickel, for production of cobalt; (B) adding a sulfide precipitation agent to said raffinate, for cobalt sulfide and zinc sulfide precipitation; (C) removing all ammonia from the sulfidized pulp (solids and liquid); (D) subjecting the filtered solid—cobalt sulfide (and impurities)—to atmospheric leaching; (E) reducing to a minimum the zinc concentration in the cobalt round, by means of solvent extraction with D2EPHA extractant diluted in solvent, in any solvent extraction system comprising the required number of extraction, scrubbing, and stripping stages, with resident time of not less than 1 minute at each of the stages used; (F) performing nickel removal by ion exchange, for nickel purification; (G) adding sodium carbonate to the solution, for cobalt carbonate precipitation; (H) leaching the produced cobalt carbonate in a system that utilizes an acid, preferably sulfuric acid, and more preferably, the anolyte from cobalt electrolysis; (I) performing cobalt electrowinning so as to recover the cobalt from the solution in its metallic form; and (J) allowing the metallic cobalt to settle on insoluble stainless steel plates during the time required for production of the cobalt cathodes.