New insights into the selective depression mechanism of galactomannan in flotation separation of chalcopyrite and talc

In this study, galactomannan (GM) was applied for the first time to the flotation separation of chalcopyrite and talc. Micro-flotation experiments demonstrated that GM exhibited better selectivity than traditional depressants such as sodium carboxymethyl cellulose (CMC) and dextrin. Optimal separation, achieving a flotation difference of 55.13 % between chalcopyrite and talc, was obtained at pH 10.8 with GM, sodium butyl xanthate (SBX), and methyl isobutyl carbinol (MIBC) dosages of 40, 30, and 30 mg/L, respectively. Infrared spectroscopy, zeta potential, and X-ray photoelectron spectroscopy analyses revealed that GM selectively inhibited SBX adsorption on talc without significantly affecting chalcopyrite. GM primarily bonded to Mg sites on talc and Cu/Fe sites on chalcopyrite. Density functional theory calculations further confirmed that GM showed stronger adsorption on talc, and differences in adsorption configurations explained its preferential inhibition of talc during flotation. This study offers guidance for flotation separation and reagent development in complex ore systems, supporting sustainable mineral resource utilization.