Selective co-adsorption of a novel mixed collector onto magnesite surface to improve the flotation separation of magnesite from dolomite

Abstract

It is difficult to effectively separate magnesite from dolomite owing to the similarity of their surface properties. In this study, a novel mixed collector of oleic acid and dodecyl phosphate was used to increase the flotation difference between magnesite and dolomite. Micro-flotation tests using sodium hexametaphosphate (SH) as a depressant were performed to evaluate the separation performance of the mixed collector. The results demonstrated that oleic acid and dodecyl phosphate as a mixed collector was more selectively promoted the flotation of magnesite. The adsorption mechanism of the mixed collector on the surfaces of the samples was studied using Zeta potential, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results suggested that the mixed collector, which is Mg-selective, was initially adsorbed on the Mg sites of the magnesite, thus making its surface hydrophobic and caused the magnesite to float and thereby separate from the dolomite.