Flotation behavior and surface adsorption mechanism of a novel selective inhibitor HDP in the separation of chalcopyrite and talc flotation

Chalcopyrite and talc exhibit strong natural hydrophobicity, making it challenging for conventional inhibitors to effectively separate the two through flotation. This paper proposes a novel starch-modified reagent, Hydroxypropyl distarch phosphate (HDP), for the separation of chalcopyrite and talc. Micro-flotation test results indicate that HDP has a significant inhibitory effect on talc, while the flotation recovery of chalcopyrite is almost unaffected. Effective separation of chalcopyrite and talc can be achieved with the addition of only 5 mg/L of HDP. Zeta potential, adsorption amount, and FTIR tests reveal that HDP can selectively adsorb onto the surface of talc, with minimal adsorption on chalcopyrite. Further analysis through XPS and AFM indicates that HDP acts on the talc surface through physical adsorption, generating a larger phase angle to inhibit talc flotation. Concurrently, Density functional theory (DFT) simulation calculations suggest the presence of hydrogen bonding during the adsorption process between HDP and talc.