Xanthate interaction and flotation separation of H2O2-treated chalcopyrite and pyrite

This study investigated the effects of H2O2 treatment on xanthate interaction and flotation separation of chalcopyrite and pyrite by making use of a series of laboratory flotation experiments and surface analysis techniques. Flotation test results showed that H2O2 treatment influenced the flotation behaviors of the two minerals; however, flotation of pyrite was depressed more significantly than that of the chalcopyrite. Under well-controlled H2O2 concentration, the selective separation of chalcopyrite from pyrite was realized at pH 9.0, at which the recovery of chalcopyrite was over 84% and that of pyrite was less than 24%. Zeta potential, UV-visible and IR spectrum measurements revealed that the collector interacted differently with the two minerals after H2O2 treatment, and the surface of chalcopyrite adsorbed much greater amount of xanthate than that of the pyrite. IR and XPS analyses showed that the H2O2 treatment significantly changed the surface properties of pyrite to very hydrophilic species that inhibited the adsorption of collector and thus depressed the floatability of pyrite. While, the surface of chalcopyrite remained mildly inert to H2O2, as a result, the adsorption of xanthate and its oxidation to dixanthogen were very effective, which enhanced the flotation of chalcopyrite.