Leaching studies of alkali roasted bomarilmenite and anatase during the processing of synthetic rutile

Abstract

The leaching of sodium (Na+) and Fe2+,3+, ions from the soda-ash roasted ilmenite (FeO–TiO2) or anatase minerals has been examined as a chemical method for beneficiating titani-ferous minerals for the production of pigment grade TiO2. In the leaching step, the roles of catalytic aeration, dilute concentrations of organic liquids (methanol) in the range of 0.5% (v/v) in 1.5% (w/v) ammonium chloride are explained. The results of leaching experiments are also compared in the presence of inorganic acid with that of ammonium salt and acetic acid for retaining the particle size. The role of pH in the removal of sodium and iron ion is also explained based on Eh–pH diagram. The paper also explains the selective separation of rare earth oxides during the processing of synthetic rutile. The data obtained at each step of processing is explained and interpreted on the basis of results obtained through XRD, SEM and EDX. Rare earth oxides are separated unattacked by the processing steps.