Interfacial differentiation of a high-performance collector adsorption enabling selective flotation separation of chalcopyrite from pyrite

Abstract

This research introduces N-butyl thiophosphoric triamide (NBPT) as a novel selective collector for chalcopyrite and investigates its adsorption characteristics and mechanisms on both chalcopyrite and pyrite surfaces. The results of single and binary mixed mineral flotation tests demonstrated that at a slurry pH of 8, an effective separation between chalcopyrite and pyrite could be achieved using NBPT as the collector and methyl isobutyl carbinol (MIBC) as the frother. Additionally, the selective adsorption mechanism of NBPT on chalcopyrite was elucidated through adsorption density measurements, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. Adsorption density analysis showed that NBPT was more inclined to adsorb on the chalcopyrite surface rather than the pyrite surface. In addition, FT-IR analysis indicated that the adsorption intensity of NBPT on chalcopyrite was much higher than that on pyrite. XPS analysis and DFT calculations further indicated that chemisorption occurs between the S atoms of NBPT itself and the Cu sites on the surface of chalcopyrite, forming S-Cu coordination bonds, whereas only physisorption occurs on the surface of pyrite. This differentiated adsorption mechanism is key to the selective collection of chalcopyrite by NBPT. In conclusion, NBPT, as an environmentally friendly collector, demonstrated broad application prospects in chalcopyrite-pyrite flotation systems.