Study on the surface activation of ilmenite by persulfate and flotation response

In this study, an innovative method was proposed to treat ilmenite by using sodium persulfate (Na2S2O8) as a surface activator to enhance the flotation of ilmenite. The action mechanism of Na2S2O8 on the ilmenite surface was investigated by micro-flotation, adsorption tests, powder contact angle, zeta potential detection, Fourier transform infrared spectroscopy (FT-IR) analysis and X-ray photoelectron spectroscopy (XPS) analysis. Micro-flotation experiments showed that recovery of the ilmenite was effectively enhanced in the pH range of 4.0 similar to 10.0 by adding Na2S2O8. The adsorption tests illustrated that the introduction of Na2S2O8 effectively enhanced the adsorption of NaOL on the surface of ilmenite. The powder contact angle tests presented that the contact angle of samples increased after treatment with Na2S2O8 and NaOL. The zeta potential testing results showed that surface potential of the ilmenite treated with Na2S2O8 and NaOL was negatively migrated in the pH ranging from 3.5 to 10.0, revealing that the mineral surface adsorbed more oleic acid anions. FT-IR analyses suggested that the chemical adsorption of oleic acid on the surface of ilmenite was enhanced after treating with Na2S2O8. XPS analyses revealed that the addition of Na2S2O8 induced a transformation of Fe (+II) into Fe (+III) and enhanced adsorption of NaOL on the ilmenite surface. A reaction model of Na2S2O8 interacting with the surface of ilmenite was proposed to interpret the activation mechanisms.