Investigating the Selectivity of Xanthates for the Flotation Separation of Base Metal and PGM Ores

The current study investigated the effects of thiol collectors on the flotation of base metals (BMs) and platinum group metals (PGMs) ores. The properties of a single-mineral flotation test were conducted using sodium isobutyl xanthate (SIBX), sodium ethyl xanthate (SEX), potassium ethyl xanthate (PEX), and sodium isopropyl xanthate (SIPX) at concentrations of 40, 60, 80, 100, and 120 g/t and pH 9. Rougher flotation recoveries higher than 85% were obtained at typical rougher mass pulls using these xanthates at various dosages, which demonstrated high selectivity properties towards both ores. The dosages of these collectors were monitored by UV-Vis in solution as a function of time at a constant pH. The UV-Vis results showed high mineral-collector interaction between the mineral surface and xanthate at 300 nm. The thiol collectors (SIPX, SEX, SIBX, and PAX) were found to be selective towards PGMs and BMs as similar increased cumulative recoveries were obtained. The structures of xanthates had an impact on the flotation recovery. For instance, iso-alkyl xanthate (SIBX) showed better consistency in terms of maximum cumulative recovery at various dosages when compared to other xanthates.