Production method for cobalt sulfate

Abstract

Provided is a method for separating impurities and cobalt without using an electrolysis process from a cobalt chloride solution containing impurities and producing a high purity cobalt sulfate. The production method includes: a first solvent extraction step (S) of bringing an organic solvent containing an alkyl phosphoric acid-based extractant into contact with a cobalt chloride solution containing impurities, and extracting zinc, manganese, and calcium into the organic solvent to separate to remove zinc, manganese, and calcium; a copper removal step (S) of adding a sulfurizing agent to a cobalt chloride solution and generating a precipitate of sulfide of copper to separate to remove copper; a second solvent extraction step (S) of bringing an organic solvent containing a carboxylic acid-based extractant into contact with a cobalt chloride solution and back extracting cobalt with sulfuric acid after extracting cobalt into the organic solvent to obtain cobalt sulfate solution; and a crystallization step (S) of the cobalt sulfate solution obtained after having undergone through the second solvent extraction step (S). These steps are sequentially executed. Without using an electrolysis process, a high purity cobalt sulfate is directly produced by separating cobalt and impurities containing manganese.