Enhanced adsorption of sodium oleate on ilmenite by Fe2+-assisted H2O2 pre-oxidation: Study on flotation separation mechanism of ilmenite from titanaugite

The development of high-efficiency beneficiation processes for ilmenite has garnered widespread attention. This study proposed the utilize of a heterogeneous Fenton catalytic technology involving H 2 O 2 and Fe 2+ to enhance ilmenite flotation. The flotation results indicated that pre-oxidation of ilmenite with H 2 O 2 -Fe 2+ before adding collector could recover over 80 % of ilmenite from titanaugite. Electron Paramagnetic Resonance and slurry iron component concentration analyses revealed that the •OH generated within the ilmenite-H 2 O 2 -Fe 2+ catalytic system could oxidize Fe 2+ to Fe 3+ . The stronger binding capability of Fe 3+ with NaOL led to a remarkable discrepancy in floatability between ilmenite and titanaugite. Zeta potential analysis further confirmed that the oxidation degree of the ilmenite surface and the adsorption of iron species were higher than those of titanaugite. Additionally, Time-of-Flight Secondary Ion Mass Spectrometry and X-ray photoelectron spectroscopy analyses provided evidence for the selective activation of ilmenite by the H 2 O 2 -Fe 2+ . Furthermore, Density Functional Theory calculations revealed that the stable adsorption of Fe 2+ and Fe(OH) 2 + offered additional active sites on the ilmenite surface for NaOL adsorption. Moreover, the adsorption of •OH significantly affected the electronic spin density of the Fe 3d orbitals of Fe atom in ilmenite, and played a crucial positive in the surface activity of ilmenite.