DISSOLUTION OF ACTINIDE OXIDES IN SUPERCRITICAL FLUID CARBON DIOXIDE MODIFIED WITH VARIOUS ORGANIC LIGANDS

摘要

The dissolution of actinide oxides in supercritical fluid carbon dioxide containing a complex of tri-n-butyl phosphate with nitric acid was investigated. It was shown for the first time that milligram amounts of uranium dioxide can be quantitatively dissolved in supercritical carbon dioxide containing this reagent and efficiently separated from plutonium, neptunium, and thorium on its supercritical fluid extraction from a mixture of their oxides. The quantitative dissolution of milligram amounts of uranium trioxide in supercritical carbon dioxide containing thenoyltrifluoroacetone and tri-n-butyl phosphate was first performed using ultrasonication. The separation of uranium (Ⅵ) and cerium (Ⅳ) in the system involved was demonstrated.