THE SYNERGISTIC EXTRACTION OF BISMUTH AND ZINC BY 2-ETHYLHEXYL PHENYLPHOSPHONIC ACID AND MICELLES OF DINONYL NAPHTHALENE SULFONIC-ACID

The extraction of bismuth(III) and zinc(II) from perchloric acid solut ions into ligroine solutions of a mixture of 2-ethylhexyl phenylphosph onic acid (HEH Phi P) and micellar dinonyl naphthalene sulphonic acid (HDNNS) extractants is reported. A synergistic enhancement of extracti on was observed for only Bi(III); the enhancement was by a factor of 9 .5. We report an aggregation number of HDNNS for Bi(III). Slope analys is, organic phase loading and continuous variation methods were employ ed to ascertain the extraction stoichiometry. The extraction stoichiom etry varies as the concentration of the micellar HDNNS in the organic phase and the acidity of the aqueous phase changes.