Effect of deep oxidation of chalcopyrite on surface properties and flotation performance

In this study, chalcopyrite was oxidized in hydrogen peroxide (H2O2) solutions of different concentrations to simulate different degrees of oxidation in real ores, and the effects of H2O2 treatment on chalcopyrite surface properties and flotation performance were investigated by surface analysis techniques and floatation experiments, which implied the reason for the poor grade and recovery of oxidized chalcopyrite concentrate in the production process of the ore. Flotation results showed that when the concentration of H2O2 increased from 0% (by weight) to 5%, the flotation recovery of chalcopyrite decreased sharply. However, with increasing H2O2 concentration from 5% to 30%, chalcopyrite recovery improved relatively to different degrees with different collector concentrations. Analyses of X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic optical emission spectrophotometry (ICP-OES) results indicated that the pretreatment with H2O2 caused that hydrophilic substance formed on chalcopyrite surface with the dissolution of copper ions, and the dissolution amount of copper increased with the increase of H2O2 concentration. UV–visible spectrophotometer and Fourier transform infrared spectrum (FTIR) studies indicated that the pretreatment of chalcopyrite with H2O2 had little effect on the adsorption amount of potassium butyl xanthate (PBX) on chalcopyrite surface. However, due to the dissolution of copper ions, PBX interacted with chalcopyrite mainly as buthyl dixanthogen (BX)2.