Investigation of the processes of obtaining plastic treatment and electrochemical behaviour of lead alloys in their capacity as anodes during the electroextraction of zinc II. Electrochemical formation of phase layers on binary PbAg and PbCa, and ternary PbAgCa alloys in a sulphuric-acid electrolyte for zinc electroextraction

Abstract

The electrochemical oxidation processes and phase formation on binary PbAg and PbCa, and ternary PbAgCa alloys during anodic treatment of the electrodes for conditions in a sulphuric acid electrolyte were investigated. The electrochemical behaviour of lead and its alloys was studied by the cyclic voltammetry method (CVA). X-ray and SEM were used for the phase composition and surface structure analysis. It was established that only the ternary plastically treated PbAg 0.5%-Ca 0.11% alloys reveal similarities to the industrially applied PbAg 1 % anodes. It may be assumed in the case of ternary alloys that the catalytic layer is composed of a dense non-conductive MnO 2 layer of crystals serving as basic sites for oxygen evolution.