Production of electrolytic manganese dioxide from purified solutions after the leaching of manganese-bearing slurry

The production of electrolytic manganese dioxide from purified solutions after the leaching of manganese-bearing slurry is investigated. The influence of the anodic current density on the electrolysis of manganese-bearing solutions is determined. The preliminary purification of manganese-bearing solutions before electrolysis is discussed. Purification of the solution at pH 6.5–7.0 ensures the maximum deposition of all the impurities that interfere with electrolysis: copper, zinc, nickel, cobalt, aluminum, phosphorus, arsenic, antimony, iron (III), and iron (II). After impurity deposition, the pulp is filtered; the hydrate deposits are washed; and the filtered liquid is sent for electrolysis to obtain electrolytic manganese dioxide. The samples of electrolytic manganese dioxide are studied by means of X-ray fluorescent analysis, X-ray phase analysis, and scanning electron microscopy. The results show that the electrolytic manganese dioxide obtained in the laboratory with anodic current density I_a = 150–200 A/m² meets all the requirements on a highly active product: the content of the basic component (MnO₂) in the experiments is 95.0–96.5 wt %.