Effect of hydrogen peroxide on the separation of copper sulfide minerals and arsenic-bearing copper minerals using flotation

摘要

Effect of oxidation treatment using hydrogen peroxide on the separation of copper sulfide minerals (i.e., chalcopyrite and bornite) and arsenic-bearing copper minerals (i.e., tennantite and enargite) was investigated in this work. Floatability of each mineral significantly decreased following the oxidation treatment. However, flotation tests using mixed mineral of chalcopyrite and arsenic-bearing copper minerals indicate that the arsenic-bearing copper minerals had a higher floatability compared to that of chalcopyrite after the oxidation treatment followed by the addition of potassium amyl xanthate (PAX). Adsorption of PAX and X-ray photoelectron spectroscopy were performed to understand the phenomenon. Adsorption test results show that PAX was more adsorbed on tennantite and enargite compared to that of chalcopyrite. The similar trend of PAX adsorption on mineral surfaces was observed in the presence of H2O2. Moreover, the oxidation treatment enhanced the PAX adsorption. This phenomenon is likely caused by the fonnation of CuSCm and Cu(OH)_2 on the mineral surfaces under oxidation treatment as the exchange sites for PAX adsorption. Meanwhile, the low adsorption of PAX and the formation of hydrophilic species on chalcopyrite might be the reason for selective flotation of chalcopyrite with enargite and tennantite. The bench scale flotation was conducted to confirm the mixed flotation phenomenon and the results suggest that the oxidation method and the addition of PAX could deliver a satisfying separation of copper sulfide minerals and arsenic-bearing copper minerals.