Liquid–liquid extraction (LLE) of iron and titanium by bis-(2-ethyl-hexyl) phosphoric acid (D2EHPA)

This work presents the results of the Fe(III) and Ti(IV) separation using D2EHPA (1.5 mol L−1 in n-dodecane), after ilmenite leaching with H2SO4. It was possible to recover over 99 wt% Ti in a two-stage process. The co-extracted Fe was stripped (>99.5 wt%) with 4.5 mol L−1 H2SO4. Fe can be extracted from this solution by D2EHPA (1.5 mol L−1 in n-dodecane) in ⩽1.2 mol L−1 H2SO4. Both metals can be stripped from the organic phase by aqueous F− (pH 4.5). The stripping and the residual acid solutions can be recycled. The LLE process is a feasible alternative for producing high purity TiO2.