Extraction of titanium dioxide (TiO2) from ilmenite and titaniferous slag



Solutions of ilmenite (FeTiO3) and a titaniferous slag, in fused Li2O. 2B2O3 and Li2O. 4B2O3, yield on cooling compounds tentatively identified as LiFe2.5Ti3O9 and Li2Fe3Ti2.5O9 respectively. Both compounds are orthorhombic, and have the pseudobrookite structure.

The ilmenite solutions yield, in addition, rutile (TiO2). The yield of rutile increases from about 1 to 24% (w/w) of the products, when the solvent is changed from Li2O. 2B2O3 to Li2O. 4B2O3. Substitution of K2O. 4B2O3 for the latter solvent decreases the yield of rutile to c. 10%. The yield of rutile is approximately in inverse proportion to the Lux—Flood basicity of the borate solvent.