Dimercaptosuccinic acid as an efficient depressant for the separation of molybdenite from chalcopyrite: Applications and mechanisms

This study presents the application of dimercaptosuccinic acid (DMSA) as a selective depressant for chalcopyrite in copper-molybdenum separation, with a systematic investigation of its mechanisms of action. Single-mineral flotation tests showed that under weakly alkaline conditions, DMSA demonstrated significant depressant effects on chalcopyrite, while having a minimal impact on the recovery of molybdenite. In artificial mixed ore tests at a DMSA dosage of 40 mg/L, the molybdenite concentrate achieved a grade of 59.86 % with a recovery of 83.04 %, while the chalcopyrite concentrate achieved a grade of 0.49 % and a recovery of only 1.18 %. Using multi-scale characterization techniques, including contact angle measurement, SEM-EDS, zeta potential analysis, LEIS, FTIR, and XPS, it was found that DMSA interacts with metal sites on the chalcopyrite surface via its -SH groups, forming a hydrophilic chelating complex. This complex prevents the adsorption of kerosene effectively. Molecular dynamics simulations further validated that DMSA enhances the density of water molecules on the chalcopyrite surface. DMSA therefore selectively depresses the flotation of chalcopyrite, enabling the efficient separation of chalcopyrite and molybdenite.