It is difficult to effectively separatemagnesite 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 betweenmagnesite and dolomite. Micro-flotation tests using sodiumhexametaphosphate (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 themixed collector, which isMg-selective, was initially adsorbed on theMg sites of themagnesite, thus making its surface hydrophobic and caused the magnesite to float and thereby separate from the dolomite. (C) 2020 Elsevier B.V. All rights reserved.