Effect of ferric ions on surface sulfidization of hemimorphite and implications for xanthate adsorption

Abstract

• Addition of Fe 3+ weakened the surface activity of hemimorphite. • The sulfidization of hemimorphite was depressed in the presence of Fe 3+ . • Adsorption of xanthate on hemimorphite surfaces was hindered by Fe 3+ . The existence of ferric ions (Fe 3+ ) in the pulp solution will severely affect the surface properties and flotation performance of targeted minerals, so its specific effect on the interaction of flotation reagents with the mineral surface must be understood. In this work, the effect of Fe 3+ on the surface sulfidization of hemimorphite was investigated, and the interaction mechanism of Fe 3+ with the hemimorphite surface was clarified. The results of time-of-flight secondary-ion mass spectrometry and X-ray photoelectron spectroscopy indicated that the addition of Fe 3+ before sulfidization generated Fe–OOH species and hindered the formation of active sulfide species on hemimorphite particles. Infrared spectroscopy and contact-angle measurements showed that the addition of Fe 3+ was detrimental to the adsorption of xanthate species on hemimorphite particles, prohibiting the formation of hydrophobic hemimorphite surfaces in the Fe 3+ –sulfidization–xanthate system. Thus, the presence of Fe 3+ in the pulp of hemimorphite was not conducive to the formation of the desired sulfidization products and stable adsorption layers of xanthate on its surface, resulting in unsatisfactory floatability of zinc oxide minerals containing hemimorphite.