During the cyanidation of gold-copper ores or concentrates, the presence of cyanide-soluble copper significantly increases the cyanide consumption. However, the consumption of cyanide and dissolved oxygen, the concentration of sulfide ions in the leaching solution decreased with the increase of PbO amount. The SEM-EDS analyzed that there was no obvious corrosion on the surface of the bornite leaching residue in the presence of 1.5 g/L. PbO, but the surface was getting very sleek. It was known from thermodynamic calculation that PbO would partially dissolve to form plumbite ions in the alkaline cyanide solution, and plumbite ions would react with sulfide ions to form PbS precipitate. The XPS analysis also proved that a large amount of undissolved PbO and PbS precipitation were adsorbed on the surface of bornite. The adhesion of PbO and PbS on the surface of bornite inhibited dissolution of bornite in the cyanide solution. (C) 2020 Elsevier B.V. All rights reserved.