Electrodeposition of MnO2-doped Pb-0.6%Sb/α-PbO2/β-PbO2 novel composite energy-saving anode for zinc electrowinning

Zinc is an important non-ferrous metal material, of which the hydrometallurgy process has requirements for anode materials. In the present work, novel Pb-0.6%Sb/α-PbO2/β-PbO2-MnO2 composite energy-saving anodes with different proportions of co-deposited MnO2 were electrodeposited and investigated, among which the optimal one was contrasted with that of Pb based anodes in long-period zinc electrowinning application. It was found that the composite anode with MnO2 concentration of 20 g·L−1 exhibited the minimum charge transfer resistance Rct of oxygen evolution reaction (6.299 Ω·cm2) and the best corrosion resistance (Ecorr 1.3134 V, icorr 3.28 × 10−4 A). The codeposition of MnO2 effectively refined the grain size and improved the electrocatalytic activity. In addition, the mechanism of MnO2 and β-PbO2 co-deposition modification was clarified. Compared with Pb based anodes in long-period zinc electrowinning application, the cell voltage and the power consumption of the novel composite energy-saving anodes were separately reduced up to 205 mV and 218.59 kWt/(t·Zn), as well as the current efficiency was improved by 1.4 %. The energy-saving effect is remarkable.