Adsorption behavior and selective regulation of tartaric acid at solid-liquid interface: For ilmenite flotation separation

Ilmenite and its main gangue minerals (titanaugite and forsterite) are challenging to separate due to their similar surface chemical properties. The flotation process is an effective method, and the use of surface modifiers is essential. There is an urgent need to develop more effective and environmentally friendly agents to address the shortcomings of existing surface modifiers and the lack of understanding of the inhibition mechanism. In this work, sodium oleate was used as a collector to investigate the inhibitory effect of tartaric acid (TA) on gangue minerals in ilmenite flotation. This was done through micro-flotation experiments, Zeta potential measurements, x-ray photoelectron spectroscopy (XPS) analysis, solution chemical simulations, molecular dynamics (MD) simulations, and density functional theory (DFT). The results demonstrated a significant decrease in the recovery rates of titanaugite and forsterite after the addition of 1 × 10^4 mol/L TA at pH = 8. TA chemically adsorbs onto the Ca and Mg sites on the surfaces of titanaugite and forsterite through carboxylic acid groups. This impedes the adsorption of anionic collectors due to electrostatic repulsion and steric hindrance, effectively inhibiting gangue minerals and achieving separation from ilmenite. [Display omitted] •TA is a good surface modifier in ilmenite flotation separation.•At pH = 7–9, TA has absolute specificity for titanaugite and forsterite.•TA can be chemically adsorbed on the surface of titanaugite and forsterite.