Dissolution and extraction of actinide oxides in supercritical carbon dioxide containing the complex of tri-n-butylphosphate with nitric acid |
| |
Authors: | Trofim I. Trofimov Maxim D. Samsonov Yurri M. Kulyako Boris F. Myasoedov |
| |
Affiliation: | Laboratory of Radiochemistry, V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Kosygin str., 19, Moscow, Russia |
| |
Abstract: | Dissolution of individual actinide oxides (Th, U, Pu, Np), or their mechanical mixtures, as well as of solid solutions U–Pu, U–Np, U–Am and U-Pu-Eu oxides in supercritical fluid carbon dioxide (SF-CO2) containing the complex of tri-n-butyl phosphate (TBP) with nitric acid (TBP–HNO3) has been investigated. The effect of the calcination temperature of solid solutions of dioxides on the separation of actinides during supercritical fluid extraction (SFE) has been studied as well. It was shown for the first time that milligram amounts of uranium dioxide could be quantitatively dissolved in (SF-CO2) containing the TBP–HNO3 complex and efficiently separated from Pu, Np, and Th during SFE of mechanical mixture of these oxides. On the contrary, both U and Pu are quantitatively dissolved in SF-CO2–TBP–HNO3 during SFE from solid solutions of U–Pu dioxide. An increase of the calcination temperature of the mixed U(IV)–Pu(IV) dioxide from 850 to 1200 °C has no influence on the relative extraction yield of these actinides during SFE. To cite this article: T. Trofimov et al., C. R. Chimie 7 (2004).RésuméDissolution d’oxides d'actinides et extraction d’éléments dans le dioxide de carbone supercritique contenant le complexe tri-n-butylphosphate–acide nitrique. La dissolution d’oxydes de Th, U, Pu et Np, de leurs mélanges et de solutions solides U–Pu, U–Np, U–Am et U–Pu–Eu dans le dioxyde de carbone supercritique (CO2-SC) contenant le complexe tri-n-butyl phosphate–acide nitrique (TBP–HNO3) a été étudiée, et notamment l’effet de la température de calcination des solutions solides. On montre que quelques milligrammes de UO2 peuvent être dissous dans le système CO2-SC–TBP–HNO3 et être séparés de Pu, Np et Th en traitant un mélange d’oxydes. En revanche, U et Pu sont dissous dans la phase CO2-SC–TBP–HNO3 durant le traitement des solutions solides U(IV)–Pu(IV). Une augmentation de la température de calcination de 850 à 1200 °C de ces solutions solides n’a pas d’effet sur le rendement d’extraction des actinides. Pour citer cet article : T. Trofimov et al., C. R. Chimie 7 (2004). |
| |
Keywords: | Supercritical carbon dioxide ActinidesMots clé s: Dioxyde carbone supercritique Actinides |
本文献已被 ScienceDirect 等数据库收录! |
|