The effects of added chloride ion on copper electrodeposition was studied using Pb-Sb anode and a stainless steel cathode in an acidic sulfate bath containing added Co2+ ion. The presence of added chloride ion in the electrolyte solution containing 150？ppm of Co2+ ion was found to increase the anode and the cell potentials and decrease the cathode potential. Linear sweep voltammetry (LSV) was used to study the effects of added chloride ion on the anodic process during the electrodeposition of copper in the presence of added ？ppm; the oxygen evolution potential is polarised by adding 10？ppm chloride ion at current densities (≥150？A/m2), and further increase in chloride ion concentration increases the polarisation of oxygen evolution reaction more at higher current densities. X-ray diffraction (XRD) showed that added chloride ion and added Co2+ ion changed the preferred crystal orientations of the copper deposits differently. Scanning electron microscopy (SEM) indicated that the surface morphology of the copper deposited in the presence of added chloride ion and added Co2+ ion has well-defined grains. 1. Introduction Copper is generally extracted through pyrometallurgical processes [1]. However several important factors such as nonavailability/depletion of high-grade ores, increasing world demand, increasing process cost like labour cost, energy cost, and so forth, and emission of highly toxic and strongly acidic sulfur-oxide gases from smelter plants creating severe environmental pollution demanded an alternative technology to overcome these problems towards the end of nineteenth century. Thus in mid of 1980, hydrometallurgical processes involving leaching, solvent extraction, and electrowinning (L/SX/EW) were widely adopted for extraction of copper from secondary sources such as oxide ores, mixed sulfide and oxide ores, low grade sulfide ores, industrial wastes from metal plating, metal finishing, wastes from metallurgical industries, scrap copper, and alloys [1]. Although copper leaching and solvent extraction have achieved a state of advanced development, the commercial success of the process is dependent upon the ability to produce high-quality final product through the electrowinning process. The high power consumption associated with this process has been the subject of many investigations in the last few years [2–6]. The attempts made so far are [7](a)improvement in mass transport for cell operation at higher-current density without significant increase in energy requirement,(b)selection of different routes for production of the copper
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