The role of HABTC’s hydroxamate and dithiocarbamate groups in chalcopyrite flotation

The adsorption mechanism and flotation performance of S-[(2-hydroxyamino)-2-oxoethyl]-N,N-dibutyl-dithiocarbamate (HABTC) to chalcopyrite (CuFeS2) particles. [Display omitted] •S-[(2-hydroxyamino)-2-oxoethyl]-N,N-dibutyl-dithiocarbamate surfactant.•HABTC hydrophobilized copper mineral particles at pH 6–10.•Chalcopyrite adsorbing HABTC is an endothermic chemisorption.•Both dithiocarbamate and hydroxamate of HABTC anchored on chalcopyrite.•Cu(II)-hydroxamate and Cu(I)-dithiocarbamate exist in Cu-HABTC species. In this paper, S-[(2-hydroxyamino)-2-oxoethyl]-N,N-dibutyl-dithiocarbamate (HABTC) was first synthesized and characterized by 1H NMR, 13C NMR and FTIR. The role of HABTC’s hydroxamate and dithiocarbamate groups in chalcopyrite flotation was evaluated by micro-flotation, bench-scale flotation, adsorption experiments, zeta potential and X-ray photoelectron spectroscopy (XPS). HABTC exhibited excellent affinity to chalcopyrite particles under pH 6–10 and achieved superior flotation recovery of copper minerals in comparison with sodium isobutyl xanthate (SIBX). The adsorption thermodynamics and kinetics elucidated that HABTC adsorption on to chalcopyrite surfaces was a spontaneously endothermic chemisorption process. Zeta potential demonstrated that HABTC might chemisorb on to the positive sites of chalcopyrite surfaces. XPS spectra further revealed that both dithiocarbamate and hydroxamate groups of HABTC anchored on chalcopyrite surfaces through Cu(II)-hydroxamate and Cu(I)-dithiocarbamate configurations, resulting in an enhanced collecting power of HABTC to chalcopyrite particles.