Behaviour of anode impurities in copper electrorefining

Many factors which affect the anode passivation during electrolysis were discussed. These factors includes the amount of slime and slime adhesiveness. The internal factor which affects the amount of slime includes the kinds, concentration and the form of impurities in the anode. The external factor includes the concentration of the dissolved oxygen and impurity ions in electrolyte and the electrolytic condition such as current density. The possibility of passivation increased markedly with an increasing amount of coexisting oxygen in anode, higher current density and greater concentration of dissolved oxygen and impurity ions in electrolyte.