Surface regulation of activated pyrite via ammonium persulfate for efficient marmatite-pyrite flotation separation

The efficient flotation separation of activated marmatite and pyrite is crucial for zinc production but remains challenging owning to their similar surface properties. This study investigates the use of ammonium persulfate (APS) as a selective depressant for pyrite. Flotation experiments demonstrated that APS effectively reduced pyrite recovery from 85.11 % to 5.57 % while preserving high marmatite recovery. To elucidate the underlying mechanism, contact angle measurements, Fourier-transform infrared spectroscopy (FTIR), zeta potential analysis, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were employed. The results indicate that APS induces selective oxidation on the pyrite surface, leading to the formation of Fe (III)-O/OH and Fe (II)-O/OH species, which inhibit Cu 2 + activation and suppress collector adsorption, thereby reducing pyrite hydrophobicity . This study advances the understanding of APS-mediated surface modification and provides valuable insights into the development of selective flotation depressants for sulfide mineral separation.