Extraction of uranium from simulated ore by the supercritical carbon dioxide fluid extraction method with nitric acid-TBP complex

Dung, L. T. K.*; Imai, Tomoki*; Tomioka, Osamu ; Nakashima, Mikio; Takahashi, Kuniaki ; Meguro, Yoshihiro  

Supercritical fluid extraction (SFE) method using supercritical CO fluid containing a complex of HNO-tri--butyl phosphate (TBP) as an extractant was applied to extract uranium from a several uranyl phosphate compounds and simulated uranium ores. Extraction method consisting of a static and a dynamic extraction processes was established and experimental condition such as pressure, temperature, and extraction time were optimized. It was found that uranium could be efficiently extracted from both of the uranyl phosphates and simulated ores by the SFE method and then it was demonstrated that SFE was useful as a pretreatment method for uranium analysis in ores.