Poster Presentation International Solvent Extraction Conference 2025

The Extraction of Tetra- and Hexa-valent Actinides by HEH[EHP] and T2EHDGA Individually and in Combination: Distribution and Speciation (123151)

Logan A Smith 1 , Artem V Gelis 1
  1. University of Nevada, Las Vegas, Las Vegas, NV, United States

This poster presents companion material to the oral presentation ‘Group Actinide Separation Process (GrASP): A Single-Solvent Process for U/TRU Recovery and Minor An/Ln Separations Using HEH[EHP] and T2EHDGA.’ We report in this poster the ideal distribution of Th(IV), Np(IV), Pu(IV), U(VI), Np(VI), Pu(VI), and Am(VI) between nitric acid and organic solutions of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and/or N,N,N′,N′-tetra(2-ethylhexyl)diglycolamide (T2EHDGA) for various acid and ligand concentrations. Most experiments used 25uM metal with 5mM hydrazine or bromate to maintain the oxidation state and scavenge nitrite. We also present conclusions on the stoichiometries of the extracted complexes based on slope analysis and crude spectrophotometric titrations, the net extraction enthalpies, and observations on the redox behaviors of the hexavalents.

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