Interaction mechanism of copper ions with the surface of sulfidized malachite and its response to flotation

Abstract

The copper ion is a common metal ion in the pulp in the beneficiation industry, and it affects the recovery of the target minerals. In this study, we investigated the interaction mechanism of copper ions with the surface of sulfidized malachite and its effect on flotation. The flotation behavior and surface hydrophobicity were studied by microflotation and contact-angle tests. The experimental results showed that the hydrophobicity of sulfidized malachite modified by a suitable concentration of copper ions was enhanced and the recovery increased. However, after high-concentration copper-ion treatment, the surface hydrophobicity and flotation recovery decreased. Adsorption tests of the collector showed that the collector consumption of sulfidized malachite modified by an appropriate amount of copper ions decreased. According to zeta-potential measurement and X-ray photoelectron spectroscopy analysis, after modification with an appropriate copper-ion concentration, the less reactive –OH component was reduced and the Cu–S component was increased, indicating that the reaction activity and sulfidization product activity of the mineral surface improved. After modification with a high copper-ion concentration, a large number of copper hydroxide complexes formed, resulting in a decrease of the mineral surface reaction activity. Finally, the sulfidization layer on the mineral surface modified by an appropriate amount of copper ions was visually characterized by time-of-flight secondary-ion mass spectroscopy.