The adsorption mechanism of N-butoxypropyl-S-[2-(hydroxyimino) propyl] dithiocarbamate ester to copper minerals flotation

In this paper, a novel surfactant, N-butoxypropyl-S-[2-(hydroxyimino) propyl] dithiocarbamate ester (BOPHPDT) was first synthesized and introduced as a flotation collector for copper minerals. The micro and bench-scale flotation results demonstrated BOPHPDT exhibited superior flotation performance for chalcopyrite in comparison with xanthates and excellent selectivity against pyrite, and the preferable pH values for its attachment to chalcopyrite surfaces were 4–8. Adsorption thermodynamics and kinetics elucidated that BOPHPDT adsorption on to chalcopyrite was a spontaneously endothermic chemisorption process. The results of in situ scanning electrochemical microscopy (SECM) and zeta potential showed that BOPHPDT might anchor on the positively charge sites of chalcopyrite surfaces to form new species. Fourier transform infrared (FTIR) spectra further elucidated that BOPHPDT might react with the Cu atoms of chalcopyrite surfaces through its CNOH and NHC(S) groups. The double chelating groups and multiple hydrophobic chains of BOPHPDT, rendered it to possess excellent affinity and hydrophobicity for improving copper minerals flotation.