Interaction of a novel depressant m-nitrobenzoate with arsenopyrite surface: DFT and experimental studies.

The selective interaction of reagents with mineral surfaces is the core basis for mineral flotation separation. Herein, the interaction mechanism of a novel depressant m-nitrobenzoate with arsenopyrite has been investigated with the help of density functional theory (DFT) simulations, supplemented by micro-flotation tests and X-ray photoelectron spectroscopy (XPS) analyses. It is found that the adsorption of m-nitrobenzoate on the surface of arsenopyrite was mainly due to the effect of –NOO– in m-nitrobenzoate. These findings provide a clear correlation between the experiments and DFT, indicating that the –NOO– in m-nitrobenzoate can adsorb on the surface of arsenopyrite via a covalent bond, thereby realizing the depress of arsenopyrite. [Display omitted] • The oxidative properties of the -NOO- exacerbate the oxidation of arsenopyrite. • The presence of π-back bonding favors the interaction between ligands and metal ions on the mineral surface. • The lone pair of electrons of the depressant gives the empty orbital of the surface metal ion to form a positive σ bond. [ABSTRACT FROM AUTHOR]