Removal of plutonium and americium from waste matrices by supercritical carbon dioxide extraction

Abstract

The extraction of plutonium from tissue paper matrix was carried out using supercritical carbon dioxide (Sc-CO

Recovery of Uranium and Plutonium from Waste Matrices Using Supercritical Fluid Extraction

“…In our earlier studies, we have demonstrated complete recovery (>99 %) of plutonium in its Pu(IV) nitrate form from simulated waste matrices (paper, glass, stainless steel and teflon) using Sc-CO 2 modified with 2 wt% φCMPO in methanol containing 0.16 N HNO 3 under supercritical experimental conditions [19]. Simulated waste containing plutonium stored for several months require addition of nitric acid for its effective removal.…”

“…un-extracted plutonium in cellulose waste matrix was estimated by leaching with 4N HNO 3 . The leaching efficiency using ultrasonication was established earlier in our laboratory and was found to be >98% [19]. After the initial studies, the plutonium bearing waste was taken after cutting it into small pieces in to a 0.1 litre SFE vessel and extraction was carried out.…”

“…tissue paper matrix was demonstrated in our laboratory using modified Sc-CO 2 [18]. In our earlier studies, complete recovery of plutonium from simulated waste matrices such as tissue, glass, teflon and stainless steel was demonstrated using Sc-CO 2 modified with octylphenyl-N, N-diisobutyl-carbamoylmethylphosphine oxide (φCMPO) in methanol [19]. In all these investigations, an analytical scale SFE was carried out, i.e.…”

Supercritical fluid extraction of uranium and thorium from nitric acid medium using organophosphorous compounds

“…The SFE of actinides from various matrices has been reported in literature [5][6][7][8][9][10][11][12][13][14][15][16][17]. The Sc-CO 2 containing chelating agent was employed for the extraction of metal ions such as transition metal ions, lanthanides and actinides [5][6][7][8][9][10][11][12][13][14][15][16][17]. The extraction of uranium from its oxide matrices was carried out using TBP-HNO 3 complex [7,10].…”

“…The extraction of uranium from its oxide matrices was carried out using TBP-HNO 3 complex [7,10]. SFE based methods were also developed and demonstrated at our laboratory for the recovery of uranium, plutonium and americium from diverse waste matrices such as polymer, cellulose, teflon and glass matrices [12][13][14][15][16][17].…”