Effect and mechanism of the xanthate/H2O2 addition order on flotation separation of chalcopyrite and sphalerite

Abstract

Oxidation will affect the flotation of sulfide ore, but both sulfide ore and xanthate are easily oxidized, the role of oxidation in the flotation separation of sulfide ore is still unclear. In this study, different single mineral flotation tests were designed to explore the role of hydrogen peroxide (H2O2) in the flotation separation of chalcopyrite and sphalerite, and artificial mixed minerals tests was conducted to verify the selective depression effect of H2O2. Ultraviolet–visible (UV–vis) spectrometer, inductively coupled plasma-mass spectrometry (ICP-MS) measurement, microcalorimetry measurement, contact angle measurement, and Fourier transform infrared (FTIR) spectrometer were used to discuss the depressive mechanism of H2O2 on sphalerite. Flotation tests with different dosing methods show that mineral self-oxidation is the main reason for its depression. Both the chalcopyrite and sphalerite can be oxidized by H2O2, and the PBX adsorbed on its surfaces can also be desorbed by H2O2. However, sphalerite is easier to oxidize than chalcopyrite, and the PBX adsorbed on the surface of sphalerite is also easier to be desorbed. Therefore, sphalerite is selectively depressed by H2O2 in the flotation of chalcopyrite in the order of “mineral + PBX + H2O2″.