The effect of magnetic field and operating parameters on cathodic copper winning in electrowinning process

Abstract

Current efficiency and quality of deposited copper are important parameters in copper electrowinning industries. The effects of imposing an external magnetic field, Fe3+ and Cu2+ mass concentrations and electrical current density on the current efficiency, the thickness of the cathodic copper sheet and its morphology in copper electrowinning process were studied at different experimental operating conditions in a cuboid cell. A full factorial design of experiment is applied here to relate current efficiency and the standard deviation (STDEV) of the thickness with and without magnetic field, Fe3+ concentration (2.5 and 3.5 g/L), Cu2+ concentration (35 and 40 g/L) and electrical current density (150 and 220 A/m2) with constant acid concentration of 175 g/L at temperature of 40 °C for a synthetic electrolyte. Scanning electron microscope (SEM) is applied in studying the surface morphology of the deposited cathodic copper in all tests. The obtained results indicated that the presence of the magnetic field and increasing Fe3+ concentration could decrease the current efficiency up to 17 and 7%, respectively. While increasing Cu2+ concentration and electrical current density increased the current efficiency. Presence of magnetic field, increasing Fe3+ concentration and electrical current density increased the thickness uniformity of copper sheets. Investigation of SEM surface images revealed variations in these main parameters had different effects on deposited cathodic copper morphology.