Separation of chalcopyrite from a siliceous copper ore using polyethylene oxide as a depressant: An experimental study complimented by theoretical investigation

Abstract

The separation of quartz and chalcopyrite during flotation in the presence of polyethylene oxide was investigated experimentally and theoretically. It was observed that the polymer adsorbs onto chalcopyrite more than onto quartz especially in high alkaline environment and this was confirmed theoretically. FTIR results of chalcopyrite-polymer system due to complexation were unveiled theoretically using quantum theory of atoms in molecules to consist of conventional hydrogen bonding with other non-covalent bonds and partially covalent interaction, while quartz-polyethylene complex was revealed to be due to conventional hydrogen bonding only. Therefore, flotation tests were performed on a mimicked siliceous-chalcopyrite synthetic mixture for Mpanda Mineral Field from Tanzania using polyethylene oxide as a chalcopyrite depressant. Flotation tests of quartz and chalcopyrite using 60 g/t of octadecan-1-amine and potassium amyl xanthate, respectively at 100 g/t and 500 g/t of polyethylene oxide at pH 10.5 ± 0.1, yielded Cu grades of 14.7% and 16.7% with recoveries of 70.7% and 75.0%. Therefore, polyethylene oxide could be a potential chalcopyrite depressant.