Experimental Findings on Minor Actinide and Lanthanide Separations using Ion Exchange

Technical Report · Fri Sep 12 04:00:00 EDT 2014

DOI:https://doi.org/10.2172/1157060· OSTI ID:1157060

Hobbs, D. T. ^[1]; Shehee, T. C. ^[1]

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1. Savannah River National Laboratory (SRNL), Aiken, SC (United States)

During FY14, experimental work focused in the following areas: (1) synthesis, characterization and testing of ion-exchange materials and (2) investigating methods to oxidize americium(III) in dilute nitric acid using peroxydisulfate. Ion-exchange materials tested at SRNL included antimony silicates. Inorganic and hybrid ion-exchange materials tested previously in this project are limited to a pH of about 2. In more concentrated acid solutions, the ion-exchange material is chemically unstable or exhibits poor ion-exchange performance for metal ions. FY14 research focused on testing antimony silicates, which had been reported to exhibit good ion-exchange in 0.2 – 1.0 M nitric acid and some ion-exchange capacity in as high as 3 M nitric acid. Performance testing of archived antimony silicate samples from Prof. R. Harjula (U. Helsinki) and freshly prepared samples showed very low affinity for lanthanide ions in 0.1, 1.0 and 3.0 M nitric acid. Tests carried out in FY14 continued work initiated the previous year to understand the effects that Pu(IV) and nitrite have on the oxidation of Am(III) by peroxydisulfate. Findings indicate that both Pu(IV) and nitrite are oxidized by peroxydisulfate. Consequently, an excess of peroxydisulfate is needed to maximize the conversion of Am(III) to Am(V).

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States); Savannah River National Laboratory (SRNL), Aiken, SC (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC09-08SR22470
• OSTI ID: 1157060
• Report Number(s): SRNL--STI-2014-00398; FCRD-SWF-2014-000230
• Country of Publication: United States
• Language: English