The influence of rare earth La on properties of lead-based alloy anode for zinc electrowinning

The development of suitable lead alloys anodes is an important target in zinc electrowinning. Here, we prepared Pb-Ag-Ca-Al-La alloys using the melting method with various La contents to investigate the influence of rare earth La on the properties of lead alloys. The effects of La content on the mechanical properties and electrochemical properties of the alloys were studied systematically. The characterization techniques including metallographic structure, hardness, tensile test, cyclic voltammetry, Tafel, electrochemical impedance spectroscopy, long-term anodic oxidation, physical composition, and surface morphology were employed to explore the detailed changes. The results show properties of the alloys have been improved to some extent when the content of La is in range 0.003–0.006%. Nevertheless, the properties of the alloy seriously deteriorate when the content of La exceed 0.01%, even worse than those of the alloy without La. The results would provide the support for the preparation and design of improved anode materials in zinc electrowinning.