Adsorption performance and mechanism of the commonly used collectors with Oxygen-containing functional group on the ilmenite surface: A DFT study

Abstract

Flotation is the main method to purify ilmenite, the success of flotation is closely related to the effective adsorption of collectors on the mineral surface. Herein, the coordination chemistry adsorption mechanism of the commonly used collectors with oxygen-containing functional groups on ilmenite surface were systematically investigated by first-principles DFT calculations. Adsorption energy results shows that the O bearing pnictogen compounds are the best for ilmenite beneficiation among all the oxygen-containing collectors. In the O-bearing pnictogen compounds, the collection performance of arsenic acid is the best, followed by phosphorous acid and phosphoric acid ester. The frontier molecular orbital analysis predicted that the collectors possessed a good chemical bonding ability with ilmenite, which is confirmed by the charge population analysis that there is significant electron transfer (bonding evidence) between collectors and ilmenite. Partialdensityofstates analysis further confirmed that the physicochemical nature of the adsorption of the collectors on the surface Ti site were ascribed to the hybridization of O 2p and Ti 3d, in which the O 2p electrons of the collectors occupied the empty orbital of Ti 3d to complete the coordination shell of surface Ti atom. This work sheds new light on the screening of solidophilic functional groups for the collector design of ilmenite beneficiation and helps to explain the adsorption mechanism of oxygen-containing collectors on the oxidized mineral surface.