First Principle Study of the Relationship between Electronic Properties and Adsorption Energy: Xanthate Adsorption on Pyrite and Arsenopyrite

Abstract

This study investigates the correlation between the electronic structure of the active sites on mineral surfaces and their adsorption capacity. Density functional theory (DFT) and flotation experiments are employed to examine the bonding behavior and adsorption enthalpy of ethylxanthate on pyrite (1 0 0) and arsenopyrite (0 0 1) surfaces. The results indicate that ethylxanthate adsorbs more significantly on pyrite than on arsenopyrite. The adsorption is chemical, primarily occurring through the orbitals of sulfur in the ethylxanthate and iron on the mineral surface. Compared to arsenopyrite, the d-band center of the iron atoms on the surface of pyrite is closer to the Fermi level; thus, the adsorption strength of ethylxanthate on the pyrite surface is greater than on arsenopyrite. The d-band centers of pyrite and arsenopyrite exhibit a direct relationship with their adsorption capacity.