Effect of Oxidation of Zinc Powder on Purification of High-Cobalt and High-Germanium Zinc Sulfate Solutions

摘要

It is popular to use zinc powder to purify electrolytic zinc sulfate solution via replacement reactions between zinc and other metals in the solution. In view of easy oxidation of zinc that affects its purification performance, in this study, the influence of oxidation of zinc powder on the purification of high-cobalt and high-germanium zinc sulfate solutions was explored. The oxidation of zinc powder was simulated by adding ZnO. It was demonstrated that the oxidation percentages of fine and coarse zinc powders should not exceed 2.5% and 1.0%, respectively, for sufficient removal of cobalt from the solution, while for removal of germanium, the corresponding values were 0.5% and 0.2%. The results can be used for guiding purification of zinc sulfate solution to meet the requirements of subsequent operation.