Selective extraction of Hf(IV) over Zr(IV) from aqueous H2SO4 solutions by solvent extraction with acidic organophosphorous based extractants

Abstract BACKGROUND The present paper describes the selective extraction of Hf( IV ) over Zr( IV ) using two acidic extractants ( D2EHPA and Cyanex 272) and its mixture with LIX 63 from sulphate medium. To achieve this, extractant and H 2 SO 4 concentrations were varied and results obtained. RESULTS Selective extraction of Hf( IV ) over Zr( IV ) was possible using D2EHPA /or Cyanex 272 at 2 mol L ‐1 and higher H 2 SO 4 solutions. For all investigated experimental conditions, D2EHPA exhibited greater efficiency than Cyanex 272 for the extraction of Hf( IV ). Compared with either D2EHPA or Cyanex 272 alone, binary extractant mixtures ( D2EHPA + LIX 63, Cyanex 272+ LIX 63) did not show much selectivity towards the extraction of Hf( IV ) over Zr( IV ). Extraction with D2EHPA at 4 mol L ‐1 H 2 SO 4 solution led to a separation factor around 30 between Hf( IV ) and Zr( IV ). CONCLUSIONS Hf( IV ) was selectively extracted over Zr( IV ) in the investigated systems, with a good separation factor. Results indicated the possibility of separating the metal ions by selective extraction of Hf( IV ). The selective extraction of Hf( IV ) is important and advantages in separation give the potential for application in nuclear science and technology. © 2013 Society of Chemical Industry