Electrolytic Recovery of Cadmium from Cyanide Washing Solutions on Filtering Carbon-Graphite Electrodes

Electrorecovery of cadmium(II) on filtering carbon-graphite electrodes from washing cyanide solutions formed in cadmium-plating of articles in a cyanide electrolyte was studied. The effect of the dilution factor of the supporting electrolyte on the run of cathodic polarization curves, pH value, and solution resistivity was analyzed. The influence exerted by the efficiency of cadmium(II) recovery on the carbon-graphite electrodes was studied in relation to current density, solution flow rate, cadmium(II) concentration in solution, dilution factor of the supporting electrolyte, and material of the carbon-graphite electrode. The possibility of dissolution of cadmium deposited onto a filtering carbon-graphite electrode via anodic dissolution or because of the operation of a short-circuited electrochemical system constituted by the carbon-graphite electrode, cadmium, and cyanide solution was considered.