Effect of Cd²⁺ on Electrodeposition of Copper in Cyclone Electrodeposition

A strategy to determine the effect of Cd²⁺ on the electrodeposition of copper from a copper electrolyte by cyclone electrowinning is presented. The concentration of Cu²⁺ in the copper electrolyte with different Cd²⁺ concentrations was determined by atomic absorption spectrometry (AAS). It indicated that the current efficiency, the rate of electrodeposition, and the rate copper electrodeposition decreased with the addition of Cd²⁺ in the three stages of electrodeposition. The current efficiency declined from 99.6 to 79.2% and the copper electrodeposition rate declined from 52 to 40% in the first electrodeposition. The current efficiency had no significant change, and the copper electrodeposition rate declined from 88 to 77% in the second electrodeposition. The current efficiency declined from 72.6 to 40.3%, and the copper electrodeposition rate was all at 99% in the third electrodeposition. The influences of the Cd²⁺ concentration on the purity and morphology of cathode copper were investigated. The effect of Cd²⁺ concentration on the purity and morphology of cathode copper was also studied. In the three-stage electrodeposition, the addition of the Cd²⁺ concentration mainly affected the microstructure of the cathode copper, but it had little effect on the purity of the cathode copper. The higher the amount of Cd²⁺, the rougher the morphology of the cathode copper and the larger the gap between the grains; the higher the amount of Cd²⁺, the lower the electrodeposition rate and current efficiency, though the reduction was small.