Solvent extraction of cobalt from cobalt sulfate solution

摘要

A process for the preparation and purification of a cobalt oxide hydroxide intermediate from a cobalt sulphate solution containing cationic and anionic impurities, including the successive steps of (i) contacting the cobalt sulphate solution with an organic reagent to extract iron and zinc cationic impurities from the sulphate solution; (ii) extracting the cobalt from the sulphate solution with an organic reagent to produce a cobalt loaded organic phase substantially free of all anionic impurities; (iii) stripping the cobalt loaded organic phase with a concentrated ammoniacal ammonium carbonate solution to produce an ammoniacal ammonium carbonate strip liquor rich in cobalt II ammines; (iv) oxidizing the cobalt II ammines in the ammoniacal ammonium carbonate strip liquor to cobalt III tetraammines; (v) extracting the majority of nickel impurity from the cobalt III tetraammine rich ammoniacal liquor with an organic reagent; and (vi) recovering the cobalt from the cobalt III tetraammine rich ammoniacal liquor.