Separation and recovery of uranium and plutonium from oxalate supernatant

The separation of uranium and plutonium from oxalate supernatant, obtained after precipitating plutonium oxalate, containing ∼ 10 g/l uranium and 30-100 mg/l plutonium in 3 M HNO3 and 0.10 - 0.18 M oxalic acid solution has been carried out. In one extraction step with 30% TBP in dodecane: ∼ 92% of uranium and ∼ 7% Pu is extracted. The raffinate containing the remaining U and Pu is extracted with 0.2 M CMPO + 1.2 M TBP in dodecane and near complete extraction of both the metal ions is achieved. The metal ions are back extracted from organic phases using suitable stripping agents. The recovery of both the metal ions separately is > 99%. The uranium species extracted into the TBP phase from the HNO3 + oxalic acid medium was identified as UO2(NO3)2 x 2TBP. (author)