Synergism mechanism of the combined NaOL-SDBS collector at solid-liquid interface and its response to flotation separation of ilmenite from pyroxene

Recovering ilmenite efficiently through froth flotation is challenging. In this research, a novel binary system of sodium oleate (NaOL) and sodium dodecyl benzene sulfonate (SDBS) was applied to promote the flotation performance of ilmenite. Using a total dosage of 90 mg/L combined NaOL-SDBS (4:1) collector, the highest flotation recovery rate of ilmenite was 91.55% at pH 5.0. Furthermore, the artificially mixed ore tests produced a concentrate with a TiO2 grade of 43.55% and a TiO2 recovery of 84.07%, confirming the promising separation performance of the combined collector. Results indicated positive synergism between NaOL and SDBS in ilmenite flotation. The synergism of the binary collector at the solid-liquid interface was identified by the analyses of adsorption amount, contact angle, surface tension, atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). Insights into the synergistic effect between NaOL and SDBS on the ilmenite flotation were mainly attributed to a significant decrease in the surface tension of solid-liquid interface, and the strong adhesion forces of co-adsorption between the combined NaOL-SDBS collector and the mineral surface.