Leaching of a copper residue, pr0duced by selected oaldation leaching of aItickel matte, in oXygenated sulfUIic acid solution with the participation of cliloridewas investigated. The effects of quallity of cliloride, flowrate of oxygen, concentration of sulfuric acid and temperature were discussed as leadring variables. Additionof chloride in small amouot into the leach slurry was justified in enhancing c0pperleaching from the residue. Leaching of a copper residue, pr0duced by selected oaldation leaching of aItickel matte, in oXygenated sulfUIic acid solution with the participation of cliloridewas investigated. The effects of quallity of cliloride, flowrate of oxygen, concentration of sulfuric acid and temperature were discussed as leadring variables. Addition of chloride in small amouot into the leach slurry was justified in enhancing cOpperleaching from the residue.