Interaction mechanism of ferrate(VI) with arsenopyrite surface and its effect on flotation separation of chalcopyrite from arsenopyrite

Abstract

Potassium ferrate (K2FeO4) was used as a novel environmental-friendly depressant, and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate (PEX) as a collector was investigated by flotation experiments, contact angle measurements, adsorption measurements, localized electrochemical impedance spectroscopy (LEIS) measurements, and X-ray photoelectron spectroscopy (XPS) analyses. The results showed that K2FeO4 strongly depressed arsenopyrite in a pH range of 4—11, and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10—4 mol/L K2FeO4 and 5×10—5 mol/L PEX at pH 8 or 10. In the presence of K2FeO4 and PEX, the contact angle and the xanthate adsorption capacity of arsenopyrite decreased significantly. LEIS measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite surface. XPS analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.