Cobalt method hydrochloride joined reactor, and then gradually adding cobalt, to dissolve and the reaction heated to 80 ℃, and depending on cobalt nitrate was added as appropriate, to generate hydrogen peroxide solution of cobalt chloride removal of iron, if necessary, adjusted by adding sodium carbonate or ammonia, to ensure complete decontamination. The purified cobalt chloride solution, adjusted with hydrochloric acid to Ph2 ~ 3. After filtration, evaporation to boiling, cooling crystallization, centrifugal separation, drying, cobalt chloride product obtained.