Investigations on the synergistic effect of combined NaOl/SPA collector in ilmenite flotation

Abstract Combined collector of different reagents is widely used in mineral flotation, while the synergistic effect mechanism remains in dispute. In this study, two anionic collectors of sodium oleate (NaOl) and styrene phosphonic acid (SPA) were applied in ilmenite flotation. Microflotation experiments showed that NaOl had a stronger collection ability than the SPA, and the mixed collector of NaOl and SPA at a molar ratio of 3:1 exhibited the best performance in ilmenite flotation. Zeta potential measurement revealed that both NaOl and SPA could adsorb onto the ilmenite surface. The practical zeta potentials of the ilmenite using a combined NaOl/SPA collector were different from the calculated value, suggesting the possible interaction between these two agents and the ilmenite surface. X-ray photoelectron spectroscopy (XPS) analysis revealed the chemical adsorption of NaOl at the Fe sites of the ilmenite surface while SPA could interact with both Fe and Ti sites at the ilmenite surface. Molecular dynamics simulation (MDS) showed that the adsorption energy improvement using a NaOl/SPA mixture could be attributed to the mutual complement of NaOl and SPA, in which NaOl were easier to generate compact adsorption structure and SPA had the ability to interact with more metal sites.