Studies on Actinides Separation in JAERI

Advanced Extraction Methods for Actinide/Lanthanide Separations

“…[5][6][7][8] During the last few decades, a number of processes for the removal of actinides from nitric acid waste streams have been reported. [9][10][11][12][13][14][15][16][17][18][19][20][21][22] With few exceptions, 13,15 these processes are based on liquid-liquid extraction procedures. Initially, a number of acidic organophosphorous extractants have been employed in the waste processing flowsheets.…”

“…Initially, a number of acidic organophosphorous extractants have been employed in the waste processing flowsheets. The studies have focused on bis(2-ethylhexyl) phosphoric acid, [14][15][16] diisodecyl phosphoric acid, 17 and bis(hexylethyl) phosphoric acid. 18 Procedures involving these acidic extractants, however, suffer from major drawbacks.…”

“…34,63 This trend can be attributed to the enhanced ability of ligand to satisfy the geometrical requirements of the metal center, but often, the improvement in binding affinity comes at the expense of selectivity. In 15, the DGA groups are tethered to the triphenoxymethane platform by only two carbons, and to test the effect of the length of this arm linker on the extraction ability, a new tri-substituted diglycolamide was synthesized with three carbons linking the DGA arms to the triphenoxymethane base (17).…”

Stripping voltammetric assay of trace technetium with a topo coated glassy-carbon electrode

“…One kind of electrode modification which was considered promising in this respect consisted of coating a glassy carbon electrode (GCE) with trin-octylphosphinoxide (TOPO) which already proved its worth in stripping voltammetric uranium assays of sea water samples without requiring an additional separation step [ 1 , 2 ]. For it is known that, similar to uranium, technetium also reacts with TOPO to give a stable complex [ 3 ] which can be extracted from hydrochloric acid solutions and the composition of which is reported to be HTcO 4 ·2 (TOPO) [ 4 ].…”

“…Since the coefficient of Tc-VII distribution in the TOPO-HCI system attains its maximum of slightly over 100 at about 3 M HCI [ 3 ], which is equivalent to an extraction extent of at least 99%, it was obvious to attempt enrichment from about 3 M HCI acid solutions.…”