Adsorption characteristics of Pb(II) species on the sulfidized malachite surface and its response to flotation

Abstract

Sulfidization flotation is the main method for recovering non-ferrous metals oxide minerals, and the sulfidization effect determines the flotation recovery of minerals. In this paper, the effect of Pb(II) on the flotation of malachite sulfidized with sodium sulfide was studied through microflotation experiments, zeta-potential determination, adsorption experiments, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The microflotation experiments revealed that the floatability of sulfidized malachite was increased after treatment with Pb(II), with the maximum flotation recovery reaching 89.8% under the experimental conditions. The zeta-potential measurements showed that Pb(II) species can adsorb on the sulfidized malachite surface, increased the active sites on the mineral surface, and promoted the adsorption of the collector. XPS analysis indicated that addition of Pb(II) changed the chemical environment of the sulfidized malachite surface, and the formation of Pb species (Pb–S) and S species (S2− and Sn2−) enhanced the sulfidization of malachite surfaces. ToF-SIMS surface and depth profile analysis were used to intuitively explore the adsorption of the reagents, and they confirmed the positive effect of Pb(II) on malachite sulfidization. These results illustrated that the adsorption of Pb(II) on the sulfidized malachite surface was conducive to its flotation recovery.