Abstract:Copper-starting-sheet cathode and graphite anode were adapted to electrowin sheet-form metallic copper from acidic cupric chloride etchant waste in diaphragm cell with cation exchange membrane. The effects of initial Cu2+ and Cl- concentration in cathode compartment, cathodic current density, bath temperature and distance on electrowinning process were investigated. The optimal conditions were obtained including initial Cl- concentration of 5.5 mol/L, initial H+ concentration of 3.0 mol/L, additives of 0.2 g/L, cathode current density of 350 A/m2, bath temperature of 36 ℃, distance 5 cm and Cu2+ concentration from 40 g/L down to 20 g/L. Under these optimum conditions, cathode current efficiency could reach 92.77%, average cell voltage could be under 3 V, dense sheet-form metallic copper could be obtained on cathode and the catholyte waste could return to prepare the new etching solution.