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- Author or Editor: R. Swarup x
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Abstract
Extraction of U/VI/ by mixtures of 8-hydroxy quinoline /Oxine/ and neutral donors was studied from 0.1M NaCl at a pH 
4.5. The presence of a neutral donor enhanced the extraction of U/VI/ and the species responsible for synergism was established to be 1
1 adduct UO2Ox2S. From the data, the equilibrium constants for the adduct formation reaction were calculated and was found to be the lowest with TBP and the highest with TOPO.
Synergistic extraction of hexavalent actinides by HTTA and neutral donors-II
Np(VI), Pu(VI)-HTTA-TBP-Benzene system
Abstract
Synergistic extraction studies on Np(VI) and Pu(VI) have been carried out as a part of the programme on the synergistic extraction of hexavalent actinides. Extraction of Np(VI) and Pu(VI) were carried out by mixtures of HTTA and TBP in benzene from aqueous perchlorate and nitrate media. Equilibrium constant values for the various reaction equilibria involved were calculated from the data obtained by using slope-ratio as well as Job’s method. The extraction of Np(VI) by the synergistic mixture from 1M nitric acid indicated that the species NpO2 (TTA) (NO3). TBP was not involved in the extraction. The log values of KA, KAB and βAB were −1.5, 2.92 and 4.43, respectively for Np(VI) and −1.63, 2.50 and 4.13 respectively for Pu(VI).
Abstract
The extraction of thorium by benzene solutions of HIPT in presence of different neutral extractants (S) was studied using perchloric, hydrochloric and sulphuric acids as aqueous media. With TBP as the donor the effect of the diluents CCl4, benzene and CHCl3 on the extraction was studied. The synergism observed was attributed to the formation of the extractable adduct Th(IPT)4 · S and, in some cases, to the extraction of additional mixed adducts involving the participation of the anion of the aqueous medium used for extraction. The adduct formation constants for the formation of Th(IPT)4 ·S were evaluated and the formation of this adduct was independently confirmed by spectrophotometric measurements. The aqueous complexing of thorium by IPT was investigated spectrophotometrically as these data were required for the quantitative interpretation of the extraction data.
Summary
The sorption of Pu from nitric acid solutions containing oxalate/fluoride was studied using an indigenously available macroporous bifunctional phosphinic acid (MPBPA) resin. Batch experiments were carried out to obtain the distribution data of Pu(IV) with a view to optimize conditions for its recovery from nitric acid waste solutions containing oxalate or fluoride ions. The measurements showed high distribution ratio (D) values even in the presence of strong complexing ions, like oxalate and fluoride, indicating the possibility of recovery of Pu from these types of waste solution. Column studies were carried out using this resin to recover Pu from the oxalate supernatant waste solution, which showed that up to 99% of Pu could be adsorbed on the resin. Elution of Pu loaded on the resin was studied using different eluting agents.
Abstract
Recovery of americium from nitric acid solutions was studied by co-precipitation as hydroxide with various ions like calcium, ferric, nickel using sodium hydroxide and ammonium hydroxide. Studies were also carried out to recover americium using lanthanum fluoride and bismuth phosphate co-precipitation. All the methods are able to co-precipitate Am quantitatively. However, co-precipitation of Am with optimum concentration iron using ammonia is found to be better from nitric acid solutions containing large concentrations of calcium ions. Approximately 2 g of Am was recovered from 150 litres of solution batch wise using iron.
