Solvent Systems Combining Neutral and Acidic Extractants for Separating Trivalent Lanthanides from the Transuranic Elements

Journal Article · Fri Apr 23 04:00:00 EDT 2010 · Solvent Extraction and Ion Exchange, 28(3):287-312

DOI:https://doi.org/10.1080/07366291003684253· OSTI ID:982298

Lumetta, Gregg J; Gelis, Artem V; Vandegrift, George F

This paper is a review of recent publications that have focused on combined extractant systems for separating trivalent actinides from the lanthanides. These mixed solvent systems combine an acidic extractant with a neutral extractant to achieve the actinide/lanthanide separation. Depending on the neutral extractant used, three categorizations of systems can be considered, including combinations of acidic extractants with 1) diamides, 2) carbamoylmethylphosphine oxides, and 3) polydentate nitrogen-donor ligands. This review of relevant publications indicates that, although there is significant potential for practical exploitation of mixed neutral/acidic extractant systems to achieve a single-step separation of trivalent actinides from acidic high-level waste solutions, the fundamental chemistry underlying these combined systems is not yet well understood. For example, although there is strong evidence suggesting that adducts form between the neutral and acidic extractants, the nature of these adducts generally is not known. Likewise, the structures of the mixed complexes formed between the metal ions and the two different extactants are not fully understood. Research into these basic phenomena likely will provide clues about how to design practical mixed-extractant systems that can be used to efficiently separate the transuranic elements from the lanthanides and other components of irradiated fuel.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 982298
• Report Number(s): PNNL-SA-69303; AF5805000
• Journal Information: Solvent Extraction and Ion Exchange, 28(3):287-312, Journal Name: Solvent Extraction and Ion Exchange, 28(3):287-312 Journal Issue: 3 Vol. 28; ISSN 0736-6299; ISSN 1532-2262
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACTINIDES
ADDUCTS
BASIC
CHEMISTRY
COMPLEXES
DESIGN
ELEMENTS
IONS
LIGANDS
LIQUID WASTES
METALS
MIXED SOLVENTS
OXIDES
POTENTIALS
RARE EARTHS
REVIEWS
SOLVENTS
SPENT FUELS
WELLS
acidic extractant
mixed solvent
neutral extractant
synergysm