Development Of The Universal Extraction (Unex) Process For The Simultaneous Recovery Of Cs, Sr, And Actinides From Acidic Radioactive Wastes

Extraction of uranium (VI) by 1.1M tri-n-butylphosphate/ionic liquid and the feasibility of recovery by direct electrodeposition from organic phase

“…The extractant, TBP, though has a few limitations has been indispensable since its introduction by Warf [2], and also does not receive any major challenges from the subsequent extractants that have been proposed as substitutes for use in PUREX process. Massive research work has been underway since then to obtain a superior alternatives to TBP, and to develop synergistic mixtures, and other solvents for efficient separation of trivalent actinides and lanthanide-actinide separations [3][4][5][6][7][8][9][10]. It is important to recognize that all these extractants are * Corresponding author.…”

“…While several actinide specific novel reagents have been developed and studied for the extraction behavior of actinides over the years [3][4][5][6][7][8][9][10], employment of a non-traditional diluent, namely, room temperature ionic liquid (RTIL) as an alternative to molecular diluents in solvent extraction processes is of recent origin [12][13][14][15][16][17][18][19][20][21]. The striking and extraordinary results accomplished in those researches induced investigation of the extraction behavior of actinides and fission products using customary extractants present in non-traditional diluents, viz.…”

Cesium and Strontium Separation Technologies Literature Review

“…In addition, a guanidine carbonate and diethylene triamine pentaacetic acid (DTPA) stripping agent mixture was identified as a satisfactory substitute for the original hydrazine-based stripping agent [52]. The UNEX process has been successfully demonstrated in centrifugal contactors using three different actual radioactive wastes in the U.S. and Russia (with waste volumes up to 100 L) [52,53]. It has also been demonstrated for 70 hours with centrifugal contactors in continuous operation by using a simulated waste feed [54].…”

“…Testing revealed that phenylpolyfluoroalkyl sulfones are promising diluents with respect to the properties evaluated; these sulfone diluents have good chemical and radiation stability, and are chemically innocuous -and surpass typical PUREX solvent explosion and fire safety indices [51]. In addition, a guanidine carbonate and diethylene triamine pentaacetic acid (DTPA) stripping agent mixture was identified as a satisfactory substitute for the original hydrazine-based stripping agent [52]. The UNEX process has been successfully demonstrated in centrifugal contactors using three different actual radioactive wastes in the U.S. and Russia (with waste volumes up to 100 L) [52,53].…”

Advanced Extraction Methods for Actinide/Lanthanide Separations

“…Moreover, the nitrogen donor should be a better ligand for the metal as opposed to sulfur, particularly since the metal-ligand bond will be smaller and the distortion away from the idealized tricapped trigonal prismatic geometry should not be as pronounced. systems wherein the addition of the synergistist CCD greatly facilitates the extraction event, [70][71][72][73][74][75][76][77] presumably due to the fact that the resulting metal complex is more soluble in the organic media with large cations. The extraction experiment with CCD and 21 will be run in the future and should produce an active extractant…”