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1.
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 ZrCl 4·DOSO, with the mixture of extractants, however, the extracted species appear to be Q 2ZrCl 6·DOSO where Q is R 3
+NH (for Alamine 336) and R 3
+N(CH 3) (for Aliquat 336). Studies on separation of 95Zr– 95Nb pair from aqueous HCl media by Alamine 336 or DOSO and their mixtures in benzene exhibit preferential extraction of 95Nb leaving behind 95Zr in the aqueous phase, and extractions have been found to depend both upon the extractant and HCl concentrations. 相似文献
2.
Solvent extraction of macro amounts of Mo(V) and Mo(VI) from HCl using Aliquat 336 in chloroform was performed for the electrochemistry of Sg. The extraction reaction attained equilibrium with a shaking time of 10 s in higher than 8 M HCl. The D values of Mo(V) obtained by the electrochemical reduction of Mo(VI) were in good agreement with those obtained by the extraction of MoCl 5, and the D values of Mo(V) were higher than those of Mo(VI). These results suggested that the reduction behavior of Sg might be studied by electrochemical reduction combined with the present solvent extraction. 相似文献
3.
Journal of Radioanalytical and Nuclear Chemistry - We have studied extraction behavior of group-6 elements Mo and W to search for suitable conditions for an on-line extraction experiment of their... 相似文献
4.
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, 5. Stripping of Cobalt from 2% Aliquat-336-Xylene Solutions | 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 | 相似文献
5.
The present scientific study on uranium(VI) solvent extraction and vanadium(V) separation from sulfate solutions using Alamine
336 as an extractant diluted in kerosene was established. The preliminary experiments indicating the uranium extraction process
will follow the solvation as well as ion-exchange mechanisms. In the present acid region (0.1–1.0 mol dm −3 H 2SO 4) it showing the ion-exchange type mechanism. Time (1–120 min) and temperature (25–55 °C) not influencing the present extraction
system. Other experimental parameters like loading capacity of Alamine 336, stripping of uranium from loaded organic phase,
recycling of Alamine 336 and separation of uranium(VI)/vanadium(V) was studied. 相似文献
6.
Solvent extraction of 137Cs, 86Rb and 42K by dipicrylaminate and tetraphenyl borate into nitrobenzene was studied from solutions containing various solvents miscible
with water. In all cases the distribution ratios of alkali metals were lower in mixed solutions than in water. In discussing
the results, water structure, ion-association, solubility of Cs(I) ionpairs, ionic strength, and organic phase effects were
taken into account.
Part III in the series Solvent Extraction of Ion-pairs. Part II. Ref. 8 相似文献
7.
Summary Molybdenum was separated from accompanying elements by extraction with Aliquat 336S in ascorbate medium. The determination was performed spectrophotometrically with Tiron. The standard deviation was found to be ±0.5%. 相似文献
8.
Niobium and tantalum which have close chemical similarities have been separated through two different methods, viz. solvent extraction and reversed phase extraction chromatography (RPEC) in tracer scale using Aliquat 336 as a liquid anion exchanger. Quantitative extraction of tantalum in the organic phase from 0.05M HF solution by 5·10 –4M Aliquat 336 solution was achieved leaving niobium in the aqueous phase. In RPEC, hydrophobized kieselguhr impregnated with Aliquat 336 was used as the stationary phase in the column from which niobium was first eluted with 0.1M HF and then tantalum with 10M HNO 3 solution. The purity of the separated isotopes in both the procedures were verified by means of gamma-ray spectrometry. 相似文献
9.
The extraction of thorium(IV) was investigated using two types of W/O microemulsion,one of which was formed by a surface-active saponified extractant sodium bis(2-ethylhexyl) phosphate(NaDEHP) and the other was formed by a mixture of an anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate(AOT) and an extractant bis(2-ethylhexyl)phosphoric acid(HDEHP) as the cosurfactant.The extraction capacities of the above two systems were higher than that of the HDEHP extraction system.High concentration of NaNO 3 showed no influence on the extraction in the NaDEHP based W/O microemulsion system,whilst reduced the extractability in the AOT-HDEHP W/O microemulsion system.The mechanism in acidic condition was demonstrated by the log-log plot method.The structure of the aggregations and the water content in the organic phase after extraction were measured by dynamic light scattering and Karl Fischer water titration,respectively.It was found that NaDEHP based W/O microemulsion broke up after extraction,while AOT-HDEHP W/O microemulsion was reserved. 相似文献
10.
Synergism has been observed in the extraction of zirconium(IV) by mixtures of Aliquat 336 or Alamine 336 with a neutral donor TBP from aq. HCl solutions. Although the extractant dependency for Zr(IV) is found to be nearly second power with respect to TBP alone, monosolvate is found to be formed for extraction by its mixture with Aliquat 336 or Almine 336. Quantitative extraction is observed with mixtures at a lower acidity than that with individual extractants. The species formed is tentatively assigned to be Q 2ZrCl 6. TBP, where
for Aliquat 336 and
for Alamine 336. 相似文献
11.
The extraction of Co/III/ by benzoylacetone solutions has been carried out from acetateacetic acid solutions. The effect of different parameters affecting the distribution coefficient of Co/III/ have been determined. Lg D for Co was found to be a third order dependent on extractant concentration and a negative first order with respect to [H +]. From the thermodynamic parameters and the data of distribution ratios, the extraction mechanism has been suggested. Addition of some electron donor compounds shows no possibility for the increase of coordination number. 相似文献
12.
The extraction of cobalt/II/ from ammonium thiocyanate solutions by di-n-pentyl sulphoxide /DPSO/, di-n-octyl sulphoxide /DOSO/ and their mixtures in carbon tetrachloride has been studied. The species extracted were found to be Co/SCN/ 2. 4S /where S=DOSO or DOSO/. Synergic effects have been observed which are ascribed to the formation of mixed ligand metal complexes. The influence of the metal concentration, temperature and the diluent on the extraction of cobalt/II/has been investigated. 相似文献
13.
The results for the extractions of divalent (manganese, cobalt, zinc and cadmium) and trivalent (gallium and indium) metals and hexavalent uranium from aqueous solutions by various extractants such as organophosphorus compounds (tributyl phosphate, trioctylphosphine oxide, di-(2-ethylhexyl)phosphoric acid and 2-ethylhexyl 2-ethylhexylphosphonic acid), sulfur-containing compound (dihexyl sulfoxide), high-molecular weight amines (trioctylamine and trioctylmethylammonium chloride) and 7-alkylated hydroxyquinoline (7-(5,5,7,7-tetramethyl-1-octen-3-yl)-8-hydroxyquinoline are discussed in the viewpoint of separation chemistry. 相似文献
14.
Journal of Radioanalytical and Nuclear Chemistry - Cd and Zn were separated from Co, from chloride solutions containing 16 different metal ions. The separation method used was liquid–liquid... 相似文献
15.
We report on a novel and selective method for the preconcentration and determination of Cr(VI) in aqueous samples. Cr(VI) is adsorbed - in a “batch mode” - on multiwalled carbon nanotubes covered with Aliquat 336 and then determined directly, i.e., on the solid, by X-ray fluorescence spectrometry. This reduces the number of reagents and minimizes sample handling. The method combines the advantages of solid-phase extraction with the benefits of the XRF method in that the large areas required by the carbon nanotubes make them a promising solid sorbent for preconcentration. The enrichment factor was calculated after considering that the thin film obtained from the 10?mL solution of 1?mg?L ?1 of Cr(VI) has a real thickness of 0.04?mm and a final diameter of 16.7?mm, so that the volume deposited on the pellet is 0.0088 cm 3 and the preconcentration factor is 1000. A novel and selective method for the preconcentration and determination of Cr(VI) in aqueous samples is proposed. Cr(VI) is adsorbed - in a “batch mode” - on multiwalled carbon nanotubes (MWCNTs) covered with Aliquat 336 and then determined directly, i.e., on the solid, by X-ray fluorescence spectrometry. This reduces the number of reagents and minimizes sample handling. 相似文献
16.
The extraction of reduced 99mTc with 5,7-dichloroxine, tributyl phosphate (TBP) and 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (PMBP) from HCl−LiCl mixtures
has been studied. A mechanism of extraction is proposed and the stability of the chlorocomplexes of technetium (V) in a hydrochloric
and—lithium chlorid—perchloric acid mixture has been established using extraction data of 99mTc and spectrophotometric measurements with 99Tc. 相似文献
17.
A solid-phase absorbent obtained by the immobilization of Aliquat 336 chloride in poly(vinyl chloride) is reported to extract preferentially Co(II) from its 7 M hydrochloric acid solutions containing Ni(II). Under the experimental conditions there was no extraction of Ni(II) which allowed the complete separation of these two ions. Co(II) was rapidly and quantitatively back-extracted with deionised water. A mechanism for the extraction of Co(II) is proposed based on the formation of the ion-pair A +[HCoCl 4] − where A + is the Aliquat 336 cation. Fe(III) and Cd(II), usually present in Co(II) and Ni(II) samples, were also extracted into the solid-phase absorbent though at a slower rate than Co(II) and they did not interfere with the separation of Co(II) from Ni(II). It was also demonstrated that this approach allowed the complete separation of Ni(II) from the other metal ions mentioned above. 相似文献
18.
A micro-cloud point extraction method was discussed for preconcentration and spectrophotometric quantification of U(VI). The method depends on complex formation between U(VI) and 2-(4-sulphophenyloazo)-1,8-dihydroxy-3,6-naphtalenedisulphonic acid (SPADNS) at pH 7.0 and subsequent extraction of the complex in a mixed surfactant medium (cethyltrimethyl ammonium bromide and Triton X-114). The separation was carried out in the presence of 1% Na 2SO 4 at room temperature. The calibration curve was linear up to 3000 µg L ?1. The enrichment factor, detection limit and precision were 16.0, 1.05 µg L ?1, and 2.3%, respectively. The method was employed for the determination of U(VI) in real samples with different matrices. 相似文献
19.
The solvent extraction of silver/I/ has been carried out in 0.5M nitric acid in presence of cyanide by 2,4-dihydroxyacetophenone thiosemicarbazone /DATS/. Ethyl acetate has been used as a solvent and quantitative recovery is made possible with 12.5-fold excess of the reagent in a single extraction. In this medium silver/I/ forms a 22 complex /metal:ligand/ with DATS. The effect of diverse ions on the extraction of silver/I/ has been investigated. 相似文献
20.
Several calixarenes were tested with the aim to find a synergic solvent extraction system with dicarbollide suitable for the extraction of europium from nitric acidic solutions. The best results were obtained with C 56H 72O 12S 4 and chlorobenzene. Data on the selectivity and interferences by other nitrates are given. The effect of the concentrations of the extractants and aqueous nitric acid was investigated. Basic data on the kinetics of the extraction reaction are presented. Attempts are described to transform this extraction reaction into an adsorption chromatographic arrangement. 相似文献
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