Separation of Minor Actinides from Lanthanides by Dithiophosphinic Acid Extractants

The selective extraction of the minor actinides (Am(III) and Cm(III)) from the lanthanides is an important part of advanced reprocessing of spent nuclear fuel. This separation would allow the Am/Cm to be fabricated into targets and recycled to a reactor and the lanthanides to be dispositioned. This separation is difficult to accomplish due to the similarities in the chemical properties of the trivalent actinides and lanthanides. Research efforts at the Idaho National Laboratory have identified an innovative synthetic pathway yielding new regiospecific dithiophosphinic acid (DPAH) extractants. The synthesis provides DPAH derivatives that can address the issues concerning minor actinide separation and extractant stability. For this work, two new symmetric DPAH extractants have been prepared. The use of these extractants for the separation of minor actinides from lanthanides will be discussed.

[1]  C. Adamo,et al.  Toward a clear-cut vision on the origin of 2,6-di(1,2,4-triazin-3-yl)pyridine selectivity for trivalent actinides: insights from theory. , 2006, Inorganic chemistry.

[2]  A. Geist,et al.  6,6′‐Bis(5,5,8,8‐tetramethyl‐5,6,7,8‐tetrahydro‐benzo[1,2,4]triazin‐3‐yl) [2,2′]bipyridine, an Effective Extracting Agent for the Separation of Americium(III) and Curium(III) from the Lanthanides , 2006 .

[3]  G. Modolo,et al.  Thermodynamic Study on the Synergistic Mixture of Bis(chlorophenyl)dithiophosphinic Acid and Tris(2-ethylhexyl)phosphate for Separation of Actinides(III) from Lanthanides(III) , 2005 .

[4]  M. Ephritikhine,et al.  The distinct affinity of cyclopentadienyl ligands towards trivalent uranium over lanthanide ions. Evidence for cooperative ligation and back-bonding in the actinide complexes. , 2005, Dalton transactions.

[5]  D. Guillaumont,et al.  Thermodynamic study of the complexation of trivalent actinide and lanthanide cations by ADPTZ, a tridentate N-donor ligand. , 2005, Inorganic chemistry.

[6]  M. Jensen,et al.  Comparison of covalency in the complexes of trivalent actinide and lanthanide cations. , 2002, Journal of the American Chemical Society.

[7]  K. Nash,et al.  ACTINIDE PARTITIONING—A REVIEW , 2001 .

[8]  M. Drew,et al.  Separation of americium(III) from europium(III) with tridentate heterocyclic nitrogen ligands and crystallographic studies of complexes formed by 2,2′∶6′,2′′-terpyridine with the lanthanides , 2000 .

[9]  R. Rogers,et al.  Thermodynamics and hydration of the europium complexes of a nitrogen heterocycle methane-1,1-diphosphonic acid , 2000 .

[10]  Z. Kolarik,et al.  EXTRACTION OF Am(lll) AND Eu(lll) NITRATES BY 2-6-DI-(5,6-DIPROPYL-1,2,4-TRIAZIN-3-YL)PYRIDINES 1 , 1999 .

[11]  Yongjun Zhu,et al.  The Separation of Am from Lanthanides by Purified Cyanex 301 Extraction , 1996 .

[12]  Yongjun Zhu.  The Separation of Americium from Light Lanthanides by Cyanex 301 Extraction , 1995 .

[13]  R. Diamond,et al.  An Ion-exchange Study of Possible Hybridized 5f Bonding in the Actinides1 , 1954 .