Study On The Oxidation Promotion Mechanism Of Ilmenite Activation Flotation

Sodium oleate is widely used in ilmenite flotation because of its low cost and high collector property.Unfortunately,the poor selectivity of this collector and incomplete separation between ilmenite and gangue minerals are the main problems encountered during ilmenite flotation.In this study,sodium oleate was used as a collector during ilmenite flotation to explore the effects of H₂O₂,KCr₂O₇,Ca?Cl O?₂,Na Cl O,KMn O₄,and other oxidants on single-mineral ilmenite flotation behaviors via the oxidization modification method.Zeta potential measurements,Fourier transform infrared spectroscopy?FTIR?,X-ray photoelectron spectroscopy?XPS?,scanning electron microscopy,and solution chemical and thermodynamics calculations confirmed that addition of KMn O₄,as an example,can oxidize and activate ilmenite to promote the flotation of ilmenite.The oxidation mechanism of ilmenite was subsequently studied,and tests of oxidant-activated ilmenite flotation were carried out.The main conclusions are as follows:?1?Sodium oleate is a suitable collector for ilmenite.Under weakly acidic conditions?p H=6?,single-mineral experiments of ilmenite showed that Na Cl O and KMn O₄ could promote ilmenite flotation.Moreover,KMn O₄and Na Cl O revealed the best activation effects on ilmenite at p H=6.Compared with that of ilmenite treated with sodium oleate only,the recovery of ilmenite increased from approximately 60%to nearly 90%.However,the amount of Na Cl O necessary to achieve the same effect under the same conditions was approximately five times the amount of KMn O₄applied.?2?Solution chemical calculations revealed that,under the condition of weak acidity or basicity,the active site of ilmenite surface is Fe.At p H<10,thermodynamic calculation showed that the Gibbs free energy of Fe³⁺(?G^?_Fe3+)was far smaller than those of Ca²⁺,Mg²⁺,Mn²⁺,and Fe²⁺.In solutions that are either weakly acidic or close to neutral,sodium oleate preferentially interacts with Fe³⁺because?G^?_Fe3+is far lower than?G^?_Fe2+.The FTIR spectra showed that sodium oleate is chemically adsorbed on the ilmenite surface and that this process is driven by KMn O₄.The XPS spectra showed that KMn O₄ promotes the valence transformation of Fe on the surface of ilmenite and increases the Fe³⁺content by 27.2%,thus enhancing the interaction between sodium oleate and Fe?III?-O.?3?Actual ore tests demonstrated that the recovery rate of Ti O₂ in ilmenite concentrate increases remarkably with increasing KMn O₄ dosage when the grinding fineness is–0.074 mm accounting for 80%.When the KMn O₄ dosage was 110 g/t,the ilmenite recovery rate increased by 11.68%and the grade decreased only slightly.KMn O₄ promotes ilmenite flotation and indirectly improves the selectivity of sodium oleate.