Surface characteristic and sulfidization-xanthate flotation behaviours of malachite as influenced by ferric ions

During the sulfidization–xanthate flotation of malachite in industrial production, Fe3+ in the pulp may affect mineral enrichment. In this study, we examined the adsorption of Fe3+ on the malachite surface and sulfidized surface to investigate the effect of Fe3+ on malachite sulfidization, sulfidization products, and mineral floatability. The results of experiments indicated that Fe3+ formed an adsorption layer on the samples surface and sulfidized samples surface, and adsorption of Fe–hydroxyl species led to hydroxylation of the samples. The proportion of Cu (I) species decreased during sulfidization, which indicated that the existence of Fe3+ had a negative effect on the sulfidization of the sample. Sulfidization products were identified, which revealed that the proportion of SO2–n increased significantly after treatment with Fe3+, suggesting that the reaction activity of the sulfidized surface was reduced. Moreover, the hydrophobicity of the mineral surface reduced after interaction with Fe3+ species, and led to reduced flotation recovery.