Effect of hydrogen peroxide on flotation behavior and mechanism of galena with different pre-adsorbed collectors

• DMPDTP, DDTC, and PAX all exhibit good collecting properties for galena. • In the presence of H₂O₂, the recovery of galena pre-adsorbed with DMPDTP on the surface is low. • In the presence of H₂O₂, the oxidation rate of galena varies depending on the pre-adsorbed collector on its surface. • When DMPDTP adsorbs onto the surface of galena, H₂O₂ causes the formation of metal oxides on the galena surface, thereby depressing its flotation. This study investigates the oxidation rate of galena when different collectors are pre-adsorbed onto its surface under the action of hydrogen peroxide (H 2 O 2 ). Subsequently, the oxidation of galena surfaces enables efficient separation from sphalerite, thereby achieving the recovery of lead and zinc resources. Galena treated with DMPDTP (dimethylphenyldithiophosphoric acid), DDTC (sodium diethyldithiocarbamate) and PAX (potassium amyl xanthate) all showed good floatability. Through flotation experiments and various experimental evaluations, this study investigates whether the flotation behavior of galena, whose surface is adsorbed with DMPDTP, PAX and DDTC, exhibits differences under the influence of H 2 O 2 . Flotation experiments show that, according to the dosing sequence of “galena + collector + 10mg/L H 2 O 2 ”, at pH=10, galena is strongly depressed when the collector is DMPDTP, and the galena recovery is only 1.61%. When DDTC and PAX were used as collectors, galena could maintain good floatability and recover more than 90%. A variety of analytical techniques, including contact angle measurement, Zeta potential analysis, Inductively coupled plasma spectrometer tests, Fourier transform infrared (FTIR) spectroscopy, Ultraviolet spectroscopy and X-ray photoelectron spectroscopy (XPS) for surface composition analysis, were used to investigate the depression of H 2 O 2 on galena. Mechanistic analysis showed that the surface of galena with pre-adsorbed DMPDTP under the action of H 2 O 2 was oxidized by H 2 O 2 to produce lead oxides, the oxides were hydrophilic to cover the galena surface, and the flotation behavior of galena was depressed. However, galena pre adsorbed with DDTC and PAX was little affected by H 2 O 2 , no hydrophilic oxides were generated, and flotation behavior was unaffected. Therefore, the flotation behavior of galena with three collectors adsorbed on the surface under the action of H 2 O 2 is different.