The Effect of Tetrathionate Ions on the Surface Chemistry and Flotation Response of Selected sulphide Minerals

This study investigated the impact of tetrathionate ions on selected sulfide mineral surfaces and their flotation response to tetrathionates using X-ray photoelectron spectroscopy (XPS), zeta potential and batch flotation studies and linking the results to previously reported electrochemistry, FTIR and microflotation studies. XPS revealed that tetrathionates have the propensity to oxidize minerals, changing the chemical composition of the mineral surface. This surface alteration renders the sulfide minerals hydrophilic through sulphoxy and hydroxy entities reducing collector adsorption as noted in FTIR and mixed potential studies. Zeta potentials showed little specific adsorption of tetrathionates on the sulfides except at moderately high concentrations, i.e., 1000 mg/L. Batch flotation showed that tetrathionates in solution depressed sulfide minerals, particularly galena, reducing its recovery to the concentrates in support of earlier microflotation results.