The electrolysis was performed at 0.2 A and 50 degrees C, the electrolyte contained 20 to 40 L(-1) of Cu and 100 to 160 g L(-1) of H(2)SO(4), and the initial reactions took place at low potential (0.4-0.6 V) until the transformation of Cu(2)S into CuS, detected by the considerable increase in cell potential. Anodic and cathodic efficiencies greater than 100% and 95%. respectively, were obtained. The bight anodic efficiencie is due to faradic and chemical dissolution too. If is also shown that the (CuS) produced as waste material can replace elemental sulphur as copper precipitating agent in ammoniacal media.