Utilizing H2O2 for the selective flotation separation of chalcopyrite and galena with their surface pre-adsorbed with Isopropyl Ethyl Thiocarbamate

•The copper-lead mixed concentrates has the same surface properties after adsorption of the collector.•H2O2 enhances the hydrophilicity of the surface of galena and has little effect on chalcopyrite.•After oxidation, galena forms a lot of metal oxides on the surface.•Metal oxides have hydrophilic properties, which inhibit the flotation of galena. Chalcopyrite and galena often coexisted in ore deposits, and they are usually processed by bulk flotation and then separated to obtain valuable mixed concentrateds. In this paper, we propose a flotation reagent strategy, that uses Isopropyl Ethyl Thiocarbamate (IPETC) and hydrogen peroxide (H2O2) to achieve different floatability on chalcopyrite and galena, it is evident that chalcopyrite and galena with IPETC adsorbed on the surface can be separated by H2O2. The flotation results show that H2O2 has a great inhibition effect on galena and exhibits a weak inhibition effect on chalcopyrite. Mixture of chalcopyrite and galena with IPETC adsorbed on the surface was successfully separated by flotation with 15 mg·L-1 H2O2 at pH 7. The inhibition mechanism of H2O2 was analyzed by contact angle measurements, single-channel scanning Inductively Coupled Plasma emission spectroscopy (single-channel ICP) analysis, Fourier Transform Infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The characterization analysis indicates that the rate of H2O2 oxidation of galena is faster, resulting in more hydrophilic oxidation products such as oxides and hydroxides on the surface of galena, while the surface of chalcopyrite is less affected by H2O2. Also, compared with chalcopyrite, the adsorbed IPETC on the galena surface can be easily blanketed by oxidation products, so realizes the effective separation of chalcopyrite and galena.