A Study on the Application Characteristics of the Insoluble MMO (Mixed Metal Oxide) Electrode for Energy Reduction of Zinc Electrowinning Process

Abstract

Objective The zinc electrowinning industry is one of the high energy consumption industries where energy saving is required. In the zinc electrowining process, electrode is a high energy consuming part. In order to reduce energy use in the electrolytic smelting industry, a comparative study was conducted on the current usage of Pb+Ag alloy electrode and insoluble composite metal oxide (MMO) electrode. Methods In this study, a comparative evaluation of energy consumption was conducted between the generally used Pb+Ag alloy electrode and an insoluble MMO electrode. Aluminum was used as a reducing electrode. The actual on-site zinc electrowinning solution and ZnSO₄ simulated solution were prepared to estimate the electrode potential, voltage, zinc deposition efficiency, and lifetime characteristics under the current density of 500 A/m². Results and Discussion The overvoltage of the insoluble MMO electrode was 28.9% lower and the voltage was 15.0% lower than that of Pb+Ag alloy electrode. The zinc deposition efficiency of the insoluble MMO electrode was higher 1.9% in the actual on-site zinc electrowinning solution and 6.3% in the simulated solution. Compared with the Pb+Ag alloy electrode in use, the insoluble composite metal oxide electrode exhibited low overvoltage, good voltage characteristics, and high current efficiency characteristics. Conclusions When the energy consumption of the Pb+Ag alloy and the insoluble MMO electrodes was compared, The insoluble MMO electrode showed 17.0% lower energy consumption in the actual on-site zinc electrowinning solution and 23.8% lower in the ZnSO₄ simulated solution than Pb+Ag alloy electrode.

Keywords

• energy consumption
• pb+ag alloy electrode
• insoluble mixed metal oxide electrode
• zinc electrowinning
• simulated solution