Mathematical Model of the Semi-Batch Countercurrent Extraction Separation of Lutetium and Ytterbium and Its Verification with Model Solutions.

Autor: Ambul, E. V., Goletskii, N. D., Naumov, A. A., Puzikov, E. A., Mamchich, M. V., Bizin, A. V., Medvedeva, A. I.
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Zdroj: Radiochemistry; Jun2023, Vol. 65 Issue 3, p288-295, 8p
Abstrakt: A mathematical model for the lutetium and ytterbium extraction separation was developed. Optimization calculations were performed for two extraction schemes of separating lutetium from ytterbium with a mobile light (extraction mixture) and heavy (nitric acid) phase using an extraction system based on 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (P507) in Isopar M. A scheme with a mobile light phase was selected, since it allows concentrating lutetium by a factor of 3–5 at the stripping stage and reducing the final volume of the separated lutetium fraction. A scheme was proposed for the separation of lutetium from ytterbium by an extraction system of 10% P507 in Isopar M–2 M HNO3 using MCE-45-12P centrifugal extractors equipped with semi-batch countercurrent and countercurrent extraction steps (67 and 5 steps, respectively). The mathematical model was verified by dynamic tests of the semi-batch countercurrent–countercurrent extraction scheme using model solutions with imitation of milligram (500 mg Yb) and decagram (20 g Yb) irradiated ytterbium targets. The possibility of separating lutetium from ytterbium with purification from Yb by a factor of 25 in 5 h was demonstrated in dynamic tests with a 500 mg target. Therewith, the mathematical model exhibited a high convergence of the outgoing chromatograms with dynamic tests. The possibility of lutetium purification from ytterbium by at least 20 times in 18.5 h of operation with a 177Lu yield (including decay) up to 82% was proved with dynamic testing of 20 g ytterbium target. Therewith, the mathematical model gives a worse separation prediction than the results of dynamic tests. Examining the effect of high ytterbium concentrations on the lutetium extraction and scrupulous simulating the distribution of components in the region of high saturations of the extract with metals should be performed for the model correction. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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