Preferential extraction of lanthanides over trivalent actinides by monoacidic organophosphates from carboxylic acids and from mixtures of carboxylic and aminopolyacetic acids

Weaver, B.; Kappelmann, F.A.

doi:10.1016/0022-1902(68)80089-2

Cited by 202 publications

(108 citation statements)

References 4 publications

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“…The error bars shown on the plot represent one standard deviation in the average distribution coefficient. The distribution data are consistent with the order of extractability of the lanthanides reported by Weaver and Kapplemann [9]. Although the distribution coefficients measured in this study are smaller due to the lower HDEHP concentration, the shape of curves through the data are generally the same.…”

Section: Resultssupporting

confidence: 91%

“…At pH 1.8 the separation factor for Am increased from 1.2 for La to 27 for Eu. The same trend was also observed at pH 3.0 where the Am separation factor increased from 5.4 for Ce to 41 for Eu [9]. The use of dissopropylbenzene as the diluent in the previous work prevents a direct comparison with the separation factors measured in the presence of TPEN and NH 4 SCN.…”

Section: Resultssupporting

confidence: 60%

“…The use of dissopropylbenzene as the diluent in the previous work prevents a direct comparison with the separation factors measured in the presence of TPEN and NH 4 SCN. The use of aliphatic diluents was reported to increase distribution ratios but lowered the separation factors of Eu from Am [9].…”

Section: Resultsmentioning

confidence: 99%

“…In 1964, Weaver and Kappelmann [8] reported the development of the TALSPEAK process to separate transplutonium elements from the lanthanides by preferentially extracting the lanthanides from an aqueous solution containing lactic acid and the sodium salt of diethylenetriaminepentaacetic (DTPA) into bis-(2-ethylhexyl)phosphoric acid (HDEHP). Under optimal conditions, Nd was the least extractable of the lanthanides and Cf was the most extractable of the transplutonium elements [9]. Weaver and Kappelmann also investigated the use of other aminopolycarboxylic acid as replacements for DTPA.…”

Section: Introductionmentioning

confidence: 99%

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Distribution of lanthanide and actinide elements between bis-(2-ethylhexyl)phosphoric acid and buffered lactate solutions containing selected complexants

Rudisill

DiPrete

Thompson

2012

J Radioanal Nucl Chem

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With the renewed interest in the closure of the nuclear fuel cycle, the TALSPEAK process is being considered for the separation of Am and Cm from the lanthanide fission products in a next generation reprocessing plant. However, an efficient separation requires tight control of the pH which likely will be difficult to achieve on a large scale. To address this issue, we measured the distribution of lanthanide and actinide elements between aqueous and organic phases in the presence of complexants which were potentially less sensitive to pH control than the diethylenetriaminepentaacetic (DTPA) used in the process. To perform the extractions, a rapid and accurate method was developed for measuring distribution coefficients based on the preparation of lanthanide tracers in the Savannah River National Laboratory neutron activation analysis facility. The complexants tested included aceto-, benzo-, and salicylhydroxamic acids, N,N,N,N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), and ammonium thiocyanate (NH 4 SCN). The hydroxamic acids were the least effective of the complexants tested. The separation factors for TPEN and NH 4 SCN were higher, especially for the heaviest lanthanides in the series; however, no conditions were identified which resulted in separations factors which consistently approached those measured for the use of DTPA.

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Section: Resultssupporting

confidence: 91%

Section: Resultssupporting

confidence: 60%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Distribution of lanthanide and actinide elements between bis-(2-ethylhexyl)phosphoric acid and buffered lactate solutions containing selected complexants

Rudisill

DiPrete

Thompson

2012

J Radioanal Nucl Chem

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show abstract

“…In a typical process trivalent lanthanide cations are selectively extracted into an organic phase containing HDEHP (bis(2-ethylhexyl)phosphoric acid, with trivalent actinides being held back in the aqueous phase through selective complexation by aminopolyacetic acids. [3][4][5] Taking inspiration from the TALSPEAK process, we have investigated an alternative approach to extraction selectivity among the felements that takes advantage of the higher valence states unique to several early actinide elements. U, Np, Pu, and Am have access to pentavalent and hexavalent states where they exist as linear dioxo-cations in aqueous solution ( i.e., actinyl ions).…”

Section: Introductionmentioning

confidence: 99%