A novel synthetic polymer depressant for the flotation separation of chalcopyrite and galena and insights into its interfacial adsorption mechanism.

[Display omitted] • A novel polymer depressant DTC-PAA was synthesized and used as galena depressant. • DTC-PAA showed excellent depressing performance on galena at pH 8.5. • Chalcopyrite was separated effectively from galena in the presence of DTC-PAA. • DTC-PAA chemisorbed on galena surface via dithiocarbamate groups and Pb sites. In this research, to achieve green effective separation of chalcopyrite and galena, a novel synthetic depressant, dithiocarbamated poly(acrylamide-allyamine) (DTC-PAA), was prepared and innovatively employed as a galena depressant. The flotation behaviours of chalcopyrite and galena were investigated by micro-flotation experiments in the absence and presence of DTC-PAA depressant comparing with potassium dichromate with O-isopropyl-N-ethyl thiocarbamate (IPETC) as the collector. The micro-flotation results showed that DTC-PAA was an effective depressant for galena in the flotation separation from chalcopyrite when using IPETC collector. Their adsorption mechanisms were unravelled by FT-IR, zeta potential, adsorption capacity measurement, XPS and DFT calculations. The results of adsorption capacity tests showed that DTC-PAA prevented the adsorption of IPETC collector on galena surface. However, DTC-PAA could not prevent IPETC from adsorbing on chalcopyrite surface. It was found that DTC-PAA depressant could chemisorb onto Pb sites of galena surface through dithiocarbamate groups in DTC-PAA. These findings were also supported by FT-IR, zeta potential, XPS analysis and DFT calculations results. It implied that DTC-PAA might be a promising alternative of the potassium dichromate depressant in the flotation separation of Cu-Pb ores. [ABSTRACT FROM AUTHOR]