Correlation of homogenization effect with flotation separation between oxidized pyrite and dolomite

This work attempts to clarify the reason for low gold recovery in Carlin-type gold ores flotation by revealing the correlation of interactions between pyrite and dolomite during the oxidation process with flotation performance. In this paper, the sulfur oxidation rate determined by Ion chromatography (IC) was adopted to evaluate the oxidation degrees of the mixed pyrite and dolomite systems. Flotation tests observed that the difference in the floating rate of pyrite and dolomite gradually decreases with the accumulation of oxidation degrees. The normalized Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) identified the homogenization effect that occurs between pyrite and dolomite surface during the oxidation process can change the affinity of the mineral surface towards the xanthate collector. Focused beam reflectance measurement (FBRM), Particle video microscope (PVM), and Extended Derjaguin–Landau–Verwey–Overbeek (E-DLVO) calculation show that the homogenization effect changes the interaction force between oxidized pyrite and dolomite, and caused the adhesion between minerals, ultimately, deteriorated the separation performance of Carlin-type gold deposits. This study can give a more detailed explanation of the reason for poor selectivity in the Carlin-type gold ores flotation.