A novel oxidation reagent scheme to realize efficient flotation separation of chalcopyrite and pyrrhotite

Magnetic separation poses challenges for the effective separation of chalcopyrite and pyrrhotite. Therefore, flotation separation has emerged as a key research focus. This study investigated the oxidative properties and flotation behavior associated with the separation of chalcopyrite and pyrrhotite using sodium periodate (NaIO4). The results of flotation test show that without adding depressant, the recovery of chalcopyrite and pyrrhotite were 91.57 % and 90.15 %, respectively. When addition of 1 x 10-3 mol/L NaIO4 and 1 x 10-4 mol/L potassium butyl xanthate, chalcopyrite and pyrrhotite achieved recovery of 88.25 % and 15.41 %, respectively. This effectively promoted the flotation separation of the two minerals. The NaIO4 oxidation reduced pyrrhotite's surface hydrophobicity by forming hydrophilic species. The S2- and Fe2+ species on the pyrrhotite surface were oxidized to hydrophilic SO4 2- and Fe3+ species, potentially forming FeOOH- species and sulfate films that hindered collector adsorption. However, the S2- species on the chalcopyrite surface were oxidized to hydrophobic S0/Sn2-, enabling the mineral to maintain its good floatability. Moreover, a descriptive model was developed to illustrate the different oxidative properties of both chalcopyrite and pyrrhotite treated with NaIO4. This study provides a new approach for the efficient enrichment and utilization of pyrrhotite.