Solvent extraction of Tc(VII) by the mixture of TBP and 2-nitrophenyl octyl ether

The extraction of Tc(VII) by the mixture of tri-n-butyl phosphate: (TBP) an d 2-nitrophenyl octyl ether (NPOE) has been studied. 0.2M NPOE-TBP can extr act Tc(VII) effectively from LM HNO3 and 1M NaOH solutions with distributio n ratios of 57.1 and 12.3, respectively. The distribution ratio of Tc(VII) decreases with increasing (>0.5M) HNO3 concentration but increases with the increase of NaOH concentration. A pH 9 NaOH solution has proven to be suit able for Tc(VII) stripping. A simple extraction-stripping cycle can remove Tc(VII) from a sodium hydroxide solution. A more sophisticated extraction p rocess is proposed to remove Tc(VII) from nitric acid solution because the co-extracted HNO3 prevents the direct stripping of Tc(VII) by NaOH solution of pH 9.