A novel activation for ilmenite using potassium permanganate and its effect on flotation response

Abstract

This study proposed a novel activation method for ilmenite by using potassium permanganate as an oxidant and a surface modifier. The valence state of iron atoms on the ilmenite surface was transformed under weak-acid conditions; therefore, the interaction between Fe sites on the ilmenite surface and sodium oleate was enhanced. The flotation of ilmenite was improved with a high recovery close to 90 %. The activation mechanism was studied via batch flotation, zeta-potential measurements, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The results showed that under weak-acid conditions, potassium permanganate promoted the interaction between sodium oleate and ilmenite. The addition of potassium permanganate resulted in new characteristic absorption peaks in the infrared spectra of the ilmenite, and the chemical shifts at 1559.78 cm−1 and 1444.94 cm−1 were greater than those of the unactivated ilmenite. The positive shift of the binding energy of Fe 2p promoted the electron supply of Fe(II) to the permanganate ions. The Fe(III) content on the ilmenite surface greatly increased, making the interaction with sodium oleate easier. Thus, potassium permanganate promoted the valence transition of Fe(II) to Fe(III) and enhanced the adsorption between minerals and collectors, which ultimately improved the flotation recovery of ilmenite.