Effect of Impurities on the Electrowinning Process of Zinc and its Removal

The effects of organic impurities(trioctyl phosphate and methyl ester),inorganic impurity ammonium and Pb2+ on the electrowinning process of zinc in ZnSO4-H2SO4 system were investigated.The methods of removing the effects on electrowinning process of zinc by organic impurity trioctyl phosphate and inorganic impurity Pb2+ were studied.The experimental results showed that methyl ester had little influence on electrowinning process of zinc while trioctyl phosphate had big influence on it.Normal electrolytic zinc can be obtained by electrowinning after adsorption treatment with active carbon.Ammonium had almost no influence on electrowinning process of zinc while Pb2+ influenced the quality of cathode zinc greatly.The addition of suitable additive SrCO3 can effectively reduce the lead content in cathode zinc after the lead plate activated,and 0# zinc can be obtained under certain conditions.