Activation of ilmenite flotation by sodium chlorite in the sodium oleate system

Development of environmentally friendly, energy-efficient, methods to improve flotation recovery of ilmenite is significant. Herein, a new method of ilmenite surface modification was developed based on sodium chlorite activation using sodium oleate as a collector. The mechanism of sodium chlorite activation was investigated via microflotation, zeta potential, Fourier transform infrared (FT-IR), contact angle, X-ray photo-electron spectros-copy (XPS), and atomic force microscopy (AFM) analyses. Flotation tests showed that the recovery of ilmenite after sodium chlorite activation was substantially increased in the sodium oleate system, with the highest re-covery of 83.18 % at pH 8. Under the simultaneous influence of sodium chlorite and sodium oleate, the zeta potential of ilmenite tended to be more negative than that of sodium oleate-treated ilmenite, and the adsorption of sodium oleate on the surface was increased. FT-IR and XPS results showed that sodium chlorite induced a chemical reaction on the surface of ilmenite, converting more Fe2+ to Fe3+ and strengthening the adsorption of sodium oleate. Both contact angle and AFM results confirmed that the activation of ilmenite by sodium chlorite significantly increased the number of active sites on the surface. Compared to the ilmenite without activation, the hydrophobic layer was thicker, thereby improving the floatability.