| openaire: EC/H2020/730480/EU//ITERAMS This work was supported by the European Union H2020 program under Grant Agreement number Horizon 2020 Framework Programme 730480.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...