The effect of galvanic interaction between chalcopyrite and pyrite on the surface chemistry and collector adsorption: Flotation and DFT study

Abstract An investigation on the surface properties and collector adsorption was conducted after the galvanic interaction of chalcopyrite and pyrite in the flotation system. The surface compositions were studied through the metal ion dissolution test and X-ray photoelectron spectroscopy (XPS) characterization. The galvanic effect on flotation behavior was examined by the flotation test of mineral mixtures; the collector adsorption on the defect chalcopyrite surfaces was analyzed by DFT calculation. The results showed that the addition of pyrite enhanced copper ion dissolution from the chalcopyrite surface significantly. Adsorption of copper ion on the pyrite surface was observed by XPS analysis. Chalcopyrite surface showed a higher oxidation degree after contacting with pyrite as polysulfide and elemental sulfur appeared. Mineral recovery from flotation tests showed the galvanic effect caused lower selectivity of chalcopyrite and pyrite with SBX as a collector. DFT study revealed that the metal-deficient chalcopyrite surface does not facilitate collector adsorption with high adsorption energy. Therefore, pyrite is galvanically protected while the oxidation dissolution of chalcopyrite is enhanced in their galvanic cell. Lower chalcopyrite recovery from mineral mixtures was obtained due to surface defection and weaken collector adsorption.