A novel method for improving sulfidization xanthate flotation of malachite: Copper-ammonium synergistic activation

Malachite, as an important copper oxide mineral, is mainly separated and recovered from ores using sulfidization xanthate flotation method. In this paper, copper ions and ammonium salts were used as activators to modify the malachite surface, which improved its reactivity and improved the sulfidization and hydrophobicity of the mineral surface. Micro-flotation test results show that the flotation recovery of malachite can be greatly improved by this synergistic activation system, compared with that upon treatment in a direct sulfidization system. Zeta potential, XPS and ToF-SIMS analysis showed that the content of highly active cuprous sulfide species and copper sites on the malachite surface increased after the copper-ammonium synergistic activation treatment. FTIR characterization and contact angle measurement indicated that more xanthate components were stably adsorbed on the malachite mineral surface after the synergistic activation of the copper-ammonium, thereby increasing the hydrophobicity of the surface. Therefore, the synergistic activation not only resulted in the enhanced sulfidization of malachite surfaces, but also enhanced the reactivity and hydrophobicity of malachite surfaces, thus promoting the hydrophobic flotation of malachite. This represents a new concept and process for the efficient flotation recovery of oxidized copper minerals.