Investigation on mechanism of sorption and aggregation properties of long-chained thiol collectors in application to polymineral copper ores

Abstract

Polish polymineral copper ores contain mainly chalcocite, chalcopyrite, bornite and covellite in very fine dispersion of pure mineral in gangue. This demands very thorough milling and high selectivity of flotation. In this paper the investigations on the flotation selectivity of chalcocite and chalcopyrite using longchained aliphatic xanthates is described. Sorption studies and electrochemical measurements employing cyclic voltammetry were performed. Additionally aggregation and flotation tests were executed. Spectacular increase of sorption rate of higher xanthates at the surfaces of examined minerals was observed. Theoretical aspect of the research applies to processes and mechanisms of xanthate sorption at the surface of sulphide minerals. At the same time aggregation of fine chalcocite and chalcopyrite particles take place in the presence of xanthates. This effect increase together with increasing alkyl chain lengh and with collector concentration. Decyl and undecyl xanthate showed the best aggregation ability. An attempt of explanation of aggregation mechanism was undertaken. Verifying flotation tests confirmed efficiency of the higher xanthates as a collectors in flotation of chalcocite and chalcopyrite fine particles. This can be applied in the practice.