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

摘要

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 H_2SO_4. It was possible to recover over 99 wt percent Ti in a two-stage process. The co-extracted Fe was stripped (>99.5 wt percent) with 4.5 mol L~(-1) H_2SO_4. Fe can be extracted from this solution by D2EHPA (1.5 mol L~(-1) in K-dodecane) in <=1.2 mol L~(-1) H_2SO_4. 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 TiO_2.