共查询到20条相似文献,搜索用时 15 毫秒
1.
I. C. Pius M. M. Charyulu C. K. Sivaramakrishnan S. K. Patil 《Journal of Radioanalytical and Nuclear Chemistry》1994,186(5):385-392
The extraction of Pu(IV) from oxalic acid-nitric acid mixtures has been investigated using a liquid anion exchanger, Aliquat-336, in xylene. The presence of oxalic acid is known to have adverse effects on the extraction of Pu(IV) by Aliquat-336. The use of cations, Al(III), Fe(III) or Zr(IV) was explored to overcome the effect of oxalic acid on Pu(IV) extraction. The data obtained reveal that Pu(IV) is quantitatively extracted by Aliquat-336, even in the presence of oxalic acid, when Al(III), Fe(III) or Zr(IV) is added. The extracted Pu(IV) can be back-extracted using aqueous ammonium carbonate. 相似文献
2.
P. K. Mishra V. Chakravortty K. C. Dash N. R. Das S. N. Bhattacharyya 《Journal of Radioanalytical and Nuclear Chemistry》1989,131(2):281-287
Liquid-liquid extractions of zirconium(IV) from aqueous HCl solutions by mixtures of Aliquat 336 or Alamine 336 and diocytl sulfoxide (DOSO) in the diluent benzene has been found to be always higher than that by any single extractant. While the cationic extractants extract Zr(IV) above 6M HCl, DOSO extracts from 4M onwards. Synergism has been observed in all cases. With any of these extractants extraction becomes almost quantitative at and above 10M HCl, but with mixtures of the cationic and neutral extractants, extraction is quantitative in the range 8–9M HCl. Although the extracted species with DOSO alone seems to be ZrCl4·DOSO, with the mixture of extractants, however, the extracted species appear to be Q2ZrCl6·DOSO where Q is R3
+NH (for Alamine 336) and R3
+N(CH3) (for Aliquat 336). Studies on separation of95Zr–95Nb pair from aqueous HCl media by Alamine 336 or DOSO and their mixtures in benzene exhibit preferential extraction of95Nb leaving behind95Zr in the aqueous phase, and extractions have been found to depend both upon the extractant and HCl concentrations. 相似文献
3.
The violet complex formed between chromium(III) DCTA can be quantitatively extracted by Aliquat-336 in chloroform as [Cr(DCTA)] [Aliquat-336]. The conditions for quantitative extraction have been established. The method facilitates the determination of chromium in the presence of other coloured cations. 相似文献
4.
R. D. Bhanushali I. C. Pius S. K. Mukherjee V. N. Vaidya 《Journal of Radioanalytical and Nuclear Chemistry》2002,254(2):299-303
A new ion exchange material prepared by impregnating Aliquat-336 on silica-gel has been investigated for the recovery of plutonium from nitric-oxalic acid solutions. The distribution ratio of Pu(IV) was studied at various concentrations of nitric and oxalic acids. The presence of Al(III) and Fe(III) in the solution, enhances the uptake of Pu(IV). Pu(IV) breakthrough capacities (btc) have been determined using 2.5 ml bed of the ion exchange material column in the absence and the presence of Al(III) and Fe(III) nitrate. The elution behavior of Pu(IV) was also studied using nitric acid solutions containing reducing agents. More than 90% of plutonium could be recovered from nitric-oxalic acid solutions. 相似文献
5.
A rapid extractive photometric method using Aliquat-336 and xylenol organe for the determination of plutonium(IV) at μg levels
has been developed. Quantitative extraction is obtained from ∼4M aqueous HNO3 medium, affording estimation in the presence of several commonly occurring impurities, viz. iron, uranium, fission products
and cladding materials. Effects of acidity, reagent concentration and diverse ions on the estimation have also been invetigated.
Unlike the well-known absorptiometric method for determining plutonium(IV) employing Arsenazo III, the procedure presented
here tolerates manyfold excesses of uranium(VI) as well as chromium(III), iron(III) and zirconium(IV), which are some of the
major contaminants of plutonium during reprocessing. 相似文献
6.
Solvent extraction of Zr(IV) from aqueous HCl solutions by mixtures of TOA and different organophosphorous bases in carbontetrachloride
solvent have been found to be always higher than that by any single extractant. Synergism has been observed in the range of
2.4–9.6M HCl. Although the species extracted with neutral donor alone seems to be ZrCl4·TOPO etc, with a mixture of extractants, however, the extracted species appears to be Q2ZrCl6·TOPO where Q is R3NH. The extraction has also been found to increase with increase in the concentration of amines and neutral donors. Enhancement
of extraction has been explained by the formation of a complex adduct in organic phase. Synergistic coefficients and apparent
formation constants of the complex adducts have also been calculated. 相似文献
7.
8.
Tracer concentrations of Hf(IV) were extracted by 60% TBP solution in benzene from 5M HClO4, 5M HCl, 6M HNO3 and 8M H2SO4 solutions, and by 1·10?4 M TOPO solution in benzene from 2M HClO4 and 2M HCl solutions in the presence of a variety of organic solvents miscible with the aqueous phase. Whereas for TBP these solvents caused an increase of HF(IV) extraction, an opposite effect was observed for TOPO. The results were discussed from the point of view of various solute-solvent and solvent-solvent interactions. 相似文献
9.
Summary The foam separation of zirconium(IV) from chloride solutions has been investigated over the 1.8–12 pH range using sodium lauryl sulphate or cetyl(trimethyl)ammonium bromide as collectors. The effects of gas flow rate, bubbling time, collector and zirconium(IV) concentrations, ageing of the metal ion, and ionic strength have been studied and the results are discussed in relation to the hydrolytic behaviour of zirconium(IV). Under optimum conditions,ca. 99.5% removal can be achieved. 相似文献
10.
Niobium cannot be separated from zirconium or hafnium when these elements occur together in solution with common anions such as chloride and sulphate. This is ascribed to the co-polymerization of niobium(V) and the hydrolysed ionic species of zirconium(IV) and hafnium(IV) to form colloidal particles. In hydrochloric acid the particles are positively charged, whereas in sulphate solution the Zr-and Hf-sulphate complexes confer a negative charge. The two cases are considered separately. 相似文献
11.
The extraction of uranium(IV) from methanolic and ethanolic nitric acid solutions was investigated. The results are discussed with regard to the complex equilibrium in the mixed aqueous-organic phase and the extraction of acid into the organic phase. 相似文献
12.
Cobalt ions in aqueous thiocyanate solution react with Aliquat-336-xylene solution to form anion-association complex which is easily extracted into the organic phase. A typical extraction procedure involves extracting a solution which is 10 ppm in cobalt and 0.06 M,
Strippant | Cobalt stripped (%) |
Na2S (M) 1.0 | 18.3 |
2.0 | 10.7 |
Na2SO3 (M) 0.1 | 10.7 |
0.5 | 49.6 |
1.0 | 52.9 |
EDA (%) 2.5 | 76.6 |
NaOH (M) 0.1 | 4.1 |
0.5 | 74.1 |
1.0 | 90.8 |
2.0 | 76.8 |
NH4OH (M) 0.1 | 24.1 |
0.5 | 91.8 |
1.0 | 97.5 |
2.0 | 99.9 |
EDTA (M) 0.02 | >99.9 |
0.05 | >99.9 |
0.1 | >99.9 |
EDTA (%) 0.1 | >99.9 |
0.5 | >99.9 |
1.0 | >99.9 |