Novel insights into the adsorption mechanism of the isopropanol amine collector on magnesite ore: A combined experimental and theoretical computational study

Abstract This paper focuses on the adsorption behavior and mechanism of the isopropanol amine collector as a novel collector on magnesite ore to expand the application of hydroxyl amine collectors and improve the efficiency of low-grade magnesite ore resource usage. Novel insights into the adsorption mechanism of the isopropanol amine collector on magnesite ore were proposed through a combined experimental and theoretical computational study. Flotation tests showed that the collector exhibited different flotation behaviors to three minerals (quartz > dolomite > magnesite). Adsorption was achieved due to the electrostatic and hydrogen bond affinities by Fourier Transform infrared spectroscopy (FTIR), and zeta potential measurements, and the exposed O on the surface was involved in the adsorption interaction. Molecular dynamics simulations confirmed the same rules of the flotation behaviors and illustrated that a compact inner layer of N-dodecyl-isopropanolamine (DIPA) formed on the quartz surface. The hydrogen bonds played a significant role in the different flotation behaviors of DIPA to quartz (O S ··H O R and O S ··H N R ), magnesite (only little O S ··H O R ), and dolomite (O S ··H O R ). Additionally, the results indicated that the flotation behaviors of DIPA were closely related to the O sites density and charge of the surfaces of three minerals. Furthermore, the results reveal some straightforward mechanisms of introducing isopropanol groups at the molecular scale, which is vital for screening the functional groups and guiding the design of the novel collectors for minerals.