Investigation of selective adsorption of sodium oleate during separation of ilmenite from titanaugite via surface magnetization

Abstract

The selective adsorption behavior of sodium oleate during the surface magnetization of ilmenite and titanaugite was investigated using magnetic separation test, contact angle and adsorb amount measurements, molecular dynamic (MD) simulation, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) detections in this study. The results revealed that the ilmenite was effectively separated from titanaugite by surface magnetization in the presence of sodium oleate and sodium silicate. The analyses of adsorption amount and contact angle manifested that sodium oleate selectively adsorbed onto ilmenite and magnetite, and which enlarged the difference of surface hydrophobicity between ilmenite and titanaugite. The MD simulation results demonstrated that the selective adsorption of sodium oleate onto ilmenite and magnetite can be ascribed to the reduction of sodium silicate on the adsorption of sodium oleate onto titanaugite. Furthermore, the XPS analysis evidenced that the adsorbed sodium silicate occupied the Ca active site for which sodium oleate adsorption and weakened the adsorption of sodium oleate on titanaugite surface. While the sodium silicate little influenced the adsorption of sodium oleate onto ilmenite surface. Hence, the sodium oleate selectively adsorbed on the surface of ilmenite and led to the selective surface magnetization of ilmenite.