Separation of Americium from a Complex Matrix by Solvent Extraction Using CyMe₄BTPhen in a Room Temperature Ionic Liquid Diluent

ABSTRACT

The extraction performance and mechanism of 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo[1,2,4]triazin-3-yl)-1,10-phenanthroline (CyMe₄BTPhen) in the room temperature ionic liquid 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₄mim][NTf₂]) have been studied and are herein reported. Americium is extracted from nitric acid solutions by cation exchange and is most efficient at low (< 1 M) nitric acid concentrations as opposed to the high (4 M) concentration preferred when using most traditional molecular diluents. The kinetics are slow, taking 24 hours to achieve quantitative extraction of americium but are greatly improved, achieving the same within 8 hours, by dilution with 1-octanol. High SF_Am/Eu > 3000 were achieved although decontamination factors for americium from more complex matrices were non-competitive with extraction using traditional molecular diluents. Modest improvements in decontamination factor were attained by the addition of the hydrophilic reagent N,N,N’,N’-tetraethyl diglycolamide (TEDGA).

KEYWORDS:

• Americium
• separation
• CyMe₄BTPhen
• ionic liquid

Acknowledgments

Funding for this project was provided by AWE and EPSRC via a studentship to JM through the Next Generation Nuclear Centre for Doctoral Training, The University of Manchester.

Disclosure statement

No potential conflict of interest was reported by the author(s).