Selective flotation of chalcopyrite and molybdenite with H₂O₂ oxidation

The selective flotation of chalcopyrite (CuFeS₂) and molybdenite (MoS₂) was studied using surface oxidation treatments (i.e., ozone (O₃) and hydrogen peroxide (H₂O₂)). The results indicated that the oxidation treatments had different effects on the wettability of chalcopyrite and molybdenite. Single mineral flotation results showed that the H₂O₂ treatment had higher separation selectivity for molybdenite and chalcopyrite compared with that of the ozone treatment. The contact angle measurement and X-ray photoelectron spectroscopy (XPS) analysis results showed that the chalcopyrite surface became hydrophilic owing to the surface deposition of oxidized iron and copper after the H₂O₂ treatment. On the other hand, the contact angle of molybdenite slightly increased following the H₂O₂ treatment at high concentrations. Possible mechanisms of this phenomenon were proposed in this work. Moreover, the separation selectivity of each oxidation method was discussed. Flotation tests using bulk Cu-Mo concentrate showed that H₂O₂ could deliver a flotation result comparable to conventional Cu-Mo flotation using NaHS.