Abstract: The effect of 2， 3-disulfanylbutanedioic acid (DMSA) on the flotability of chalcopyrite and molybdenite with kerosene as a collector was investigated. The interaction mechanism between the DMSA and minerals was explored via Zeta potential analysis and quantum-chemistry calculation. Flotation results showed that DMSA has strong depression effect on chalcopyrite but slightly inhibition effect on molybdenite. Optimal separation efficiency is obtained when DMSA concentrate was only 1/9~1/13 of sodium sulphide. According to the results of Zeta potential test， DMSA adsorbs both on chalcopyrite and molybdenite surface， but the adsorption ability of DMSA on chalcopyrite surface is much stronger than that on molybdenite. The results of quantum-chemistry calculation indicated that electrochemical reaction only occurs between DMSA and chalcopyrite but not between DMSA and molybdenite.

Key words: chalcopyrite, molybdenite, flotation separation, 2, 3-disulfanylbutanedioic acid, Zeta potential, frontier orbital