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.