Anodic behaviour of the Pb-Co_3O_4 composite coating in copper electrowinning

摘要

The electrochemical and corrosion properties of Pb-Co_5O_4 (about 3 percent Co) composite anode for copper electrowinning without additives as well as in the presence of two combinations of organic additives in the electrolyte have been investigated and compared with those of Pb-Sb 5.85 percent anode. The formation of PbO_2 layer on the surface of these electrodes was traced by cyclic voltametric measurements using rotating disc electrode (RDE) method. The Pb-Co_3O_4 composite anode shows a depolarizing effect on the process of oxygen evolution as compared to Pb-Sb anode. The corrosion rate of Pb-Co_3O_4 anode during prolonged polarization is approximately 6.7 times lower than that of Pb-Sb anode. The influence of the tested organic additives on the anodic behaviour of both anodes is negligible.