Flotation separation of ilmenite and titanaugite by sodium oleate (NaOL)/ cetyltrimethylammonium bromide (CTAB) mixed collectors: Selectivity and synergistic adsorption mechanism

The feasibility of using sodium oleate (NaOL) and cetyltrimethylammonium bromide (CTAB) as mixed collectors in the flotation separation of ilmenite and titanaugite was explored. Flotation tests demonstrated that the selectivity and collecting ability of the mixed collectors were superior to those of NaOL or CTAB used alone. The mixed NaOL/CTAB could increase the TiO2 grade and recovery in the concentrate by 9.49% and 46.28% compared to single collectors, respectively. Surface tension analysis revealed a significant synergistic effect and higher surface activity of the NaOL/CTAB mixture in solution. Zeta potential indicated that both mineral surfaces in the mixed collector system were primarily influenced by CTAB adsorption. Contact angle, adsorption amount, and Time of flight secondary ion mass spectrometry findings revealed that NaOL and CTAB had significantly higher adsorption capacity on ilmenite surface compared to titanaugite. Specifically, CTAB within the mixed collector system significantly promoted the adsorption of NaOL on ilmenite. Conversely, NaOL reduced the adsorption of CTAB on both mineral surfaces and amplified the adhesion difference of CTAB between titanaugite and ilmenite. Furthermore, X-ray photoelectron spectroscopy analysis confirmed that NaOL principally interacted with the Fe site on ilmenite through chemisorption, while CTAB predominantly exhibited electrostatic adsorption on ilmenite. Molecular dynamics simulations further validated the significant adsorption differences between the mixed NaOL/CTAB system on titanaugite and ilmenite. Therefore, the separation of ilmenite from titanaugite was successfully achieved by combining the excellent selectivity of NaOL with the strong collecting ability of CTAB.