Preparation and properties of Pb/Pb-MnO2 composite anode for zinc electrowinning

A new type of Pb/Pb-MnO2 composite anode was prepared by composite electrodeposition, the effects of particle size and crystal of MnO2, electrodes configuration and electrodeposition time on the particles content in co-deposit were studied, and the optimum conditions of anode preparation were ascertained by orthogonal experiments. The electrocatalytic activity for oxygen evolution reaction (OER) of the composite anode was evaluated by cyclic voltammetry (CV) and galvanostatic polarization method. The results indicate that Pb/Pb-MnO2 composite deposit containing 1%~10% (mass fraction, %) MnO2 particles can be obtained in the fluoborate solution of lead plating. In the stimulant evaluation of industrial electrowinning, the composite anode prepared under the optimal conditions is about 300 mV, more active than the pure lead anode at the initial stage of electrolysis, and the stable potential after 24 h is 100 mV lower than that of pure lead anode, which is equal to that of Pb-Ag(0.6%) anode.