Mechanism of Cu-Pb selective flotation separation based on quercetin as a novel depressant

This study presents an organic reagent, quercetin, as a flotation depressant used to effectively separate chalcopyrite and galena. Quercetin and O-isopropyl-N-ethyl thionocarbamate (IPETC) are used as depressants and collectors, respectively, and results of micro-flotation tests showed that quercetin can depress galena and has less effect on chalcopyrite. Tests of artificially mixed samples of the chalcopyrite and galena show that the separation effect of quercetin as a depressant is better than that of sodium sulfate and sodium silicate combined depressant, it is close to that of potassium bichromate as a depressant, that is, it has the potential to be a depressant to achieve selective separation of chalcopyrite and galena. The X-ray Photoelectron Spectroscopy and Fourier Transform Infrared Spectroscopy results demonstrate that quercetin can chemisorb with oxidized metal sites on minerals’ surfaces. Results of the contact angle, adsorption capacity, and Atomic Force Microscope show that quercetin has comparable adsorption amounts on both minerals’ surfaces, and can hinder the IPETC adsorption on the mineral surface, but the amount of IPETC adsorb on chalcopyrite is much higher than on galena surfaces. The differences in the adsorption of the collector on their surface are the main reason for realizing the separation of chalcopyrite from galena.