Abstract:Co-grinding three nonferrous metal oxides (CuO, PbO and ZnO) with element sulphur under mild conditions and flotation of the ground samples were conducted to investigate the surface properties and floatability of the oxides. Phase transition, morphological features, electrochemical properties and surface chemical compositions of ground samples were studied. The results show that the floatability of CuO is improved after grinding with sulfur, by the formation of surface layer with properties similar to CuS due to the Cu—S bonding. The floatability of PbO is deteriorated after mechanochemical processing due to surface carbonation and the formation of PbS and PbSO4 by disproportionation reaction with sulfur. ZnO shows no evident response to mechanochemical sulfidation.

Key words: grinding; nonferrous metal oxides; flotation; sulfur; recycling