Effect of H2O2 on the Separation of Mo-Bi-Containing Ore by Flotation

Hydrogen peroxide (H2O2) is a strong oxidizer that causes non-selective oxidation of sulfide minerals, and its influence on bismuth sulfide ores is not well-documented. In this study, H2O2 was proposed as an alternative bismuthinite depressant, and its effect on a Mo-Bi-containing ore was intensively investigated by batch flotation tests. Results showed that the addition of H2O2 significantly destabilized the froth phase, thus decreasing the solids and water recovery. The recovery of bismuth in molybdenum concentrate was dramatically decreased to 4.64% by H2O2 compared with that in the absence of H2O2 (i.e., 50.14%). The modified first-order kinetic model demonstrated that the flotation rate of molybdenite slightly declined after H2O2 addition, whereas that of bismuthinite was drastically reduced from 0.30 min−1 to 0.08 min−1 under the same condition. Simulation revealed that H2O2 affected the floatability of both molybdenite and bismuthinite but resulted in more detrimental effect to bismuthinite. Hence, H2O2 has the potential to act as an effective depressant in bismuth sulfide ore flotation.