Selective galena depression mechanism of tea polyphenol in chalcopyrite flotation

•Tea polyphenol was proposed for the first time as a depressant for galena.•Adsorption of the collector on the surface of galena was hindered after treatment with tea polyphenol.•Tea polyphenols adsorb on the surface of galena, occupying the active site of the pre elements.•Tea polyphenol, as a depressant, offer the advantages of being environmentally friendly, effective, and readily accessible. In this study, the selective galena depression mechanism of tea polyphenol (TP) was investigated in chalcopyrite flotation. The feasibility of using TP as a galena depressant was studied through flotation experiments, and the depressant mechanism of TP on galena was analyzed using contact angle measurements, zeta potential measurements, adsorption experiments, X-ray photoelectron spectroscopy (XPS) analysis, and time-of-flight secondary ion mass spectrometry (ToF-SIMS) tests. Artificially mixed mineral flotation tests were performed at a pH of 8, TP concentration of 4 × 10–4 mol/L, and SIX concentration of 2 × 10–4 mol/L, resulting in a copper concentrate with a recovery of 83.07 % and a copper grade of 29.32 %. The lead recovery and grade of the copper concentrate were 8.87 % and 7.87 %, respectively, demonstrating the feasibility of using TP as a galena depressant. The zeta potential measurements and adsorption experiments showed that the adsorption of SIX on the surface of chalcopyrite was less affected by the TP treatment, while the TP significantly hindered the adsorption of SIX on the surface of galena, which the galena ToF-SIMS test results further support.