INVESTIGATION OF THE PROCESSES OF OBTAINING PLASTIC TREATMENT AND ELECTROCHEMICAL-BEHAVIOR OF LEAD ALLOYS IN THEIR CAPACITY AS ANODES DURING THE ELECTRO-EXTRACTION OF ZINC .2. ELECTROCHEMICAL FORMATION OF PHASE LAYERS ON BINARY PB-AG AND PB-CA, AND TERNARY PB-AG-CA ALLOYS IN A SULFURIC-ACID ELECTROLYTE FOR ZINC ELECTRO-EXTRACTION

The electrochemical oxidation processes and phase formation on binary Pb-Ag and Pb-Ca, and ternary Pb-Ag-Ca alloys during anodic treatment o f the electrodes for conditions in a sulphuric acid electrolyte were i nvestigated. The electrochemical behaviour of lead and its alloys was studied by the cyclic voltammetry method (CVA). X-ray and SEM were use d for the phase composition and surface structure analysis. It was est ablished that only the ternary plastically treated Pb-Ag 0.5%-Ca 0.11% alloys reveal similarities to the industrially applied Pb-Ag 1% anode s. It may be assumed in the case of ternary alloys that the catalytic layer is composed of a dense non-conductive MnO2 layer of crystals ser ving as basic sites for oxygen evolution.