Extraction of zinc(II), iron(III) and iron(II) with binary mixtures containing tributyl phosphate and di(2-ethylhexyl)phosphoric acid or CYANEX 302

Abstract

The extraction of zinc(II), iron(III) and iron(II) with TBP and its binary mixtures with DEHPA and CYANEX 302 from hydrochloric acid solutions was studied. It was found that the extraction ability of zinc(II) chlorocomplexes from hydrochloric acid solutions decreased in the order: TBP > TBP:HL=3:1 vol/vol > TBP:HL=1:1 vol/vol. Iron(III) was strongly extracted by TBP and its binary mixtures with DEHPA and CYANEX 302, and the extraction fell in the order: binary mixtures with DEHPA or CYANEX 302> TBP> DEHPA >> CYANEX 302. Iron(II) was not extracted by the considered extractants. Zinc(II) could not be selectively extracted in the presence of iron(III). Contrary, iron(III) could be selectively extracted, especially with the binary 1:1 vol/vol mixtures of TBP with DEHPA or CYANEX 302. The stripping of zinc(II) could be accomplished in three successive stages using water and 0.1 M H 2SO4. Iron(III) could be stripped in three stages with 0.1 M H2SO4.