共查询到20条相似文献,搜索用时 15 毫秒
1.
S. Singh V. Chakravortty K. C. Dash 《Journal of Radioanalytical and Nuclear Chemistry》1988,127(5):349-356
Solvent extraction of thorium/IV/ by a commercially available chelating extractant LIX-54 /a -diketone derivative/ /HA/ and its mixtures with tri-n-butyl phosphate /TBP/, thenoyltrifluoroacetone /HTTA/ and tri-n-octyl phosphineoxide /TOPO/ in benzene as the diluent have been studied. Quantitative extraction of thorium/IV/ by the mixture of 10% LIX-54 and 0.1M TOPO was noticed at pH 2.8. Influence of various concentrations of HTTA and TOPO in their mixtures with LIX-54 on the extraction of the same metal ion has been investigated and pronounced synergism was observed. Slope analyses determination shows the extracted species to be possibly of the type [Th/TTA/2/A/2] in case of extraction by mixtures of HTTA and LIX-54. Slopes of the linear plots were computed employing regression analysis, and variance in results has been shown. 相似文献
2.
Ms. S. Singh C. R. Panda V. Chakravortty K. C. Dash 《Journal of Radioanalytical and Nuclear Chemistry》1988,120(1):65-73
Solvent extractions of thorium(IV) and uranium(VI) by a commercially available chelating extractant LIX-26 (an alkylated 8-hydroxyquinoline) or 8-hydroxyquinoline, benzoic or salicylic acid, dipentyl sulphoxide (DPSO) and their mixtures with butanol as modifier in benzene/methylisobutyl ketone (MIBK) as the diluent have been studied. Extraction of uranium(VI) by 10% LIX-26 and 10% butanol in benzene becomes quantitative at pH 5.0. The pH 0.5 values for the extraction of thorium(IV) and uranium(VI) are 4.95 and 3.35, respectively. Quantitative extraction of thorium(IV) by the mixture of 0.1 M oxine and 0.1 M salicylic acid in methylisobutyl ketone was observed at pH 5.0. The influence of concentration of various anions on the extraction of Th4+ by mixtures of LIX-26 and benzoic acid has been studied. Studies on extraction of thorium(IV) and uranium(VI) by mixtures of LIX-26 (HQ) and DPSO show that the extracted species are possibly of the type [ThQ2/DPSO/2/SCN/2] and [UO2Q2/DPSO/], respectively. 相似文献
3.
Mao Jia-Jun Jia Wei-Jie Shao Xing-Zhi Chen Yu-De 《Journal of Radioanalytical and Nuclear Chemistry》1991,147(2):287-295
The synergistic extraction of uranium(VI) from hydrochloric acid solution with five chelating agents: 1-phenyl-3-methyl-4-benzoylpyrazolone-5 (PMBP), 1-phenyl-3-methyl-4-acetylpyrazolone-5 (PMAP), 1-phenyl-3-methyl-4-(2-chlorobenzoyl)pyrazolone-5 (PMCBP), 1-phenyl-3-methyl-4-(p-nitrobenzoyl)pyrazolone-5 (PMNBP) and 1-phenyl-3-methyl-4-trifluoroacetylpyrazolone-5 (PMTFP) plus the neutral extractants tributylphosphate (TBP), dioctyl sulfoxide (DOSO) and trioctylphosphine oxide (TOPO) in chloroform has been investigated. The extraction coefficients have been found to be greater for such mixtures than the individual component. The formulas of the extracted species have been determined to be UO2A2B (where HA = chelating agent, B = neutral extractant). Extraction power of these chelating agents increases as follows: PMCBP>PMNBP>PMTFP=PMBP>PMAP. Synergistic extraction power of the neutral extractants increases as follows: TOPO>DOSO>TBP. The extraction equilibrium constants have been calculated. The mechanism of the synergistic extraction and possible structure of the extracted species are discussed. 相似文献
4.
P. K. Mishra V. Chakravortty K. C. Dash N. R. Das S. N. Bhattacharyya 《Journal of Radioanalytical and Nuclear Chemistry》1989,134(2):259-264
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 Q2ZrCl6. TBP, where
for Aliquat 336 and
for Alamine 336. 相似文献
5.
J. N. Mathur M. S. Murali P. R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》1991,152(1):127-135
Extraction of Am(III) by dihexyl N,N-diethylcarbamoylmethyl phosphonate (CMP) in benzene from nitric acid solutions (pH 2.0 to 6.0M) has been studied. High extraction of Am(III) by CMP from 2–3M HNO3 was observed. The species extracted was found to be Am(NO3)3·3CMP. The extraction was also done with mixtures of CMP+TBP and CMP+TOPO, where mixed species were extracted in the organic phase. The back-extraction experiments gave an efficient back-extraction of Am(III) by pH 2.0 (HNO3) from the loaded CMP+TBP phase but a poor back-extraction from the loaded CMP+TOPO phase. The loading of Nd(III) by mixture of CMP and TBP was 50% of the CMP concentrations at a total Nd(III) concentration of 0.182M. The thermodynamic parameters of Am(III) extraction by a mixture of CMP and TBP were evaluated by temperature variation method, which suggests that the two-phase reaction is stabilized by enthalpy and opposed by entropy. 相似文献
6.
K. C. Rout P. K. Mishra V. Charkavortty K. C. Dash 《Journal of Radioanalytical and Nuclear Chemistry》1994,181(1):3-10
Quantitative extraction of uranium(VI) is observed from 0.2M HCl by 5% (v/v) Cyanex 301. The extraction decreases with increasing acid concentration. Mixtures of Cyanex 301 with tri-n-butyl phosphate (TBP), didecyl sulfoxide (DDSO) and Alamine 308 result in significant synergism in the extraction process, where a species of the type UO2R2. L is proposed to be extracted [RH=Cyanex 301 and L=TBP, DDSO or Alamine 308]. Significant extraction of uranium(VI) by 5% (v/v) Alamine 308 is observed at and above 2M HCl, which increases with further increase in acidity attaining a maximum at 6M, after which a slight decrease in extration is observed. Mixtures of Alamine 308 with TBP or DDSO result in a synergism, where a species of the type (R
3
NH)2 UO2Cl4. Lis extracted. [R
3
N=Alamine 308, L=TBP or DDSO]. Mixtures of Alamine 308 and Cyanex 301 at 2M HCl result in a profound antagonism in the extraction of uranium(VI). 相似文献
7.
P. Behera R. Mishra V. Chakravortty 《Journal of Radioanalytical and Nuclear Chemistry》1993,173(1):161-169
Liquid-liquid extraction of uranium (VI) from aqueous phosphoric acid solution by triisodecylamine (Alamine 310), tri-n-butyl phosphate (TBP), di-n-pentyl sulfoxide (DPSO) and their mixtures in benzene in the range 1–10M aqueous H3PO4 shows that extraction is maximum (80%) in the higher acidity range 6–8 M. Extraction of this metal ion by bis(2,4,4-trimethylpentyl)phosphinicacid (Cyanex 301) and its mixtures studied in the range 0.2–1.0M aqueous H3PO4 is far from being quantitative. Antagonism in extraction by mixtures of extractants is observed in most of the cases. Extraction of molybdenum(VI) under identical conditions shows that it is quantitative in the lower acidity range upto 2M H3PO4. Separation of uranium(VI) from molybdenum(VI) is feasible by Alamine 310, TBP and DPSO, the order of efficiency being TBP>DPSO>Alamine 310. 相似文献
8.
A. S. Solovkin 《Journal of Radioanalytical and Nuclear Chemistry》1974,21(1):15-29
Thermodynamic treatment of the experimental data on the extraction of quadrivalent Pu, U, Th and Zr with tri-n-butyl phosphate (TBP) from nitric acid solutions is presented. It is shown that the extraction of all the quadrivalent metals studied is going according to the same mechanism: M(OH)4?i+(4?i)NO 3 ? +2TBP?M(OH)i(NO3)4?i·2 TBP. For Zr, i=0, 1, and 2; for the remaining M(IV), i=0 and 1. The thermodynamic constants of extraction of M(IV) with the kerosene solutions of TBP according to the above mentioned equation are as follows: Zr: K 0 0 =0.6; K 1 0 =14; K 2 0 =5. Pu: K 0 0 =380; K 1 0 =4.8·104. U: K 0 0 =300; K 1 0 =1.8·104. Th: K 0 0 ~150. It has been established that Zr and Pu(IV) are extracted into 2-thenoyltrifluoracetone (HA) from perchloric acid solutions under the formation of MA4 and M(ClO4)A3 species. For the extraction from nitric acid solutions, the species formed are ZrA4 and Zr(NO3)A3 in the case of Zr, PuA4 and Pu(OH)A3 in the case of Pu. The differences in the qualitative and quantitative characteristics of the extraction of M(IV) with TBP and HA from nitric and perchloric acids are explained by the effect of the character of the acid and of ionic potential upon the structure of the hydration shell of M aq 4+ . 相似文献
9.
V. Gopalakrishnan P. S. Dhami A. Ramanujam M. V. Balarama Krishna M. S. Murali J. N. Mathur R. H. Iyer A. K. Bauri A. Banerji 《Journal of Radioanalytical and Nuclear Chemistry》1995,191(2):279-289
Bench-Scale studies on the partitioning and recovery of minoractinides from the actual and synthetic sulphate-bearing high level waste (SBHLW) solutions have been carried out by giving two contacts with 30% TBP to deplete uranium content followed by four contacts with 0.2M CMPO+1.2M TBP in dodecane. The acidity of the SBHLW solutions was about 0.3M. In the case of actual SBHLW, the final raffinate contained about 0.4% -activity originally present in the HLW, whereas with synthetic SBHLW the -activity was reduced to the background level.144Ce is extracted almost quantitative in the CMPO phase,106Ru about 12% and137Cs is practically not extracted at all. The extraction chromatographic column studies with synthetic SBHLW (aftertwo TBP contacts) has shown that large volume of waste solutions could be passed through the column without break-through of actinide metal ions. Using 0.04M HNO3>99% Am(III) and rare earths could be eluted/stripped. Similarly >99% Pu(IV) and U(VI) could be eluted.stripped using 0.01M oxalic acid and 0.25M sodium carbonate, respectively. In the presence of 0.16M SO
4
2–
(in the SBHLW) the complex ions AmSO
4
+
, UO2SO4, PuSO
4
2+
and Pu(SO4)2 were formed in the aqueous phase but the species extracted into the organic phase (CMPO+TBP) were only the nitrato complexes Am(NO3)3·3CMPO, UO2(NO3)2·2CMPO and Pu(NO3)4·2CMPO. A scheme for the recovery of minor actinides from SBHLW solution with two contacts of 30% TBP followed by either solvent extraction or extraction chromatographic techniques has been proposed. 相似文献
10.
M. Eskandari Nasab 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(3):1739-1747
The extraction of thorium(IV) and uranium(VI) from nitric acid solutions has been studied using mixtures of bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex272 or HA), and synergistic extractants (S) such as tri-butylphosphate (TBP), tri-octylphosphine oxide (TOPO) or bis(2,4,4-trimethylpentyl)thiophosphinic acid (Cyanex301). The results showed that these metallic ions are extracted into kerosene as Th(OH)2(NO3)A·HA and UO2(NO3)A·HA with Cyanex272 alone. In the presence of neutral organophosphorus ligands TBP and TOPO, they are found to be extracted as Th(OH)2(NO3)A·HA·S and UO2(NO3)A·HA·S. On the other hand, Th(IV), U(VI) are extracted as Th(OH)2(NO3)A·HA·2S and UO2(NO3)A·HA·S in the presence of Cyanex301. The addition of neutral extractants such as TOPO and TBP to the extraction system enhanced the extraction efficiency of both elements while Cyanex301 as an acidic extractant has improved the selectivity between uranium and thorium. The effect of TOPO on the extraction was higher than other extractants. The equilibrium constants of above species have been estimated by non-linear regression method. The extraction amounts were determined and the results were compared with those of TBP. Also, it was found that the binding to the neutral ligands by the thorium–Cyanex272 complexes follows the neutral ligand basicity sequence. 相似文献
11.
T. Omori M. Tadokodo Y. Suzuki H. Suganuma K. Yoshihara 《Journal of Radioanalytical and Nuclear Chemistry》1994,181(1):71-76
Solvent extraction mechanism of pertechnetic acid with TBP from perchloric acid solutions is discussed. When cyclohexane is used as a diluent of TBP, perchloric acid can be extracted in the form of HClO4(TBP)2 into the organic phase. The TBP extraction of pertechnetic acid competes with perchloric acid and its equilibria are expressed as follows: HTcO4+3TBPHTcO4(TBP)3 and HTcO4(TBP)3+TBPHTcO4(TBP)4. 相似文献
12.
M. Knothe 《无机化学与普通化学杂志》1980,470(1):216-226
Investigations on the Extraction of the Platinum-Group Metals from Hydrochloric-Acid Solutions by the Use of Tributyl Phosphate Comparative investigations on the extraction of Rh, Pd, Ir, and Pt from hydrochloric acid solutions by the use of tributyl phosphate (TBP) have been carried out in various organic phases (type of the ester and diluting agent) and in aqueous phases (concentration of the platinum group metals, acidity, salt additives). Pretreatment of aqueous initial solutions to avoid disturbances by metastable complexes was of special importance. Extraction proceeded rapidly and was reversible. Extractibility of the platinum group-metals and its dependence upon the extraction conditions decreased in the following order: The structure of the extracted compound (schematically represented by [H+(H2O)x(TBP)y]n[MeClm]) is assumed to be uniform and, based on this assumption, the extraction results are discussed. 相似文献
13.
M. L. P. Reddy G. P. Preetha C. V. Meena T. Prasada Rao C. S. P. Iyer A. D. Damodaran 《Journal of Radioanalytical and Nuclear Chemistry》1996,211(2):305-316
The extraction of Zn(II) and Cd(II) from thiocyanate solutions with bis-2-ethylhexyl sulphoxide (B2EHSO) in benzene as an extractant has been studied by tracer techniques. For comparison, extraction has also been carried out with tributylphosphate (TBP). The extraction data have been analysed by both graphical and theoretical methods by taking into account complexation of the metal in the aqueous phase by inorganic ligands and plausible complexes extracted into the organic phase. The results demonstrate that Zn(II) is extracted as Zn(SCN)2·2B2EHSO and Zn(SCN)2·2TBP. In the case of Cd(II), the extracted species are Cd(SCN)2·4B2EHSO/4TBP. The synergistic extraction of Zn(II) and Cd(II) with mixtures of 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP) and B2EHSO or TBP or trioctylphosphine oxide (TOPO) from acetate buffer solutions has also been investigated. Zn(II) is extracted as Zn(PMBP)2·B2EHSO/TBP/TOPO. On the other hand, Cd(II) is found to be not extracted with these mixed-ligand systems under the experimental conditions. These results also demonstrate the mutual separation of Zn(II) and Cd(II) using the synergistic extraction with HPMBP in the presence of various neutral oxodonors. 相似文献
14.
R. N. Singh S. Sujatha G. K. Mishra 《Journal of Radioanalytical and Nuclear Chemistry》1990,146(6):427-436
The distribution ratios for the extraction of Zr(IV) by TBP and its binary mixtures with DMSO or Py in n-dodecane in the presence of HNO3, and HClO4 have been determined. Based on stoichiometric and slope analysis methods a possible mechanism for the extraction has been proposed. 相似文献
15.
16.
Synergistic extraction of uranyl ion with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP) and oxo donors with widely varying basicity, viz. diphenyl sulfoxide (DPSO), tri-n-butyl phosphate (TBP) and tri-n-octylphosphine-oxide (TOPO) has been studied at various fixed temperatures. Results indicate that the equilibrium constants in the organic phase for addition reactions (KS) with these donors follow their order of basicity (KH) viz. DPSO (0.033)<TBP (0.16)TOPO (8.9) with log KS values of 3.70, 4.28 and 6.45, respectively. The thermodynamic parameters associated with the formation of these systems have been evaluted by the temperature coefficient method. The results indicate that the complex in the organic phase for DPSO and TBP is stabilized only by enthalpy, whereas both enthalpy and entropy contribute to the stabilization of the TOPO complex. Also, enthalpy contribution is more prominent as compared with the UO
2
2+
/HTTA/TOPO system, where both enthalpy and entropy contribute almost equally. 相似文献
17.
Alaaeldine Sh. Saleh Jong-Il Yun 《Journal of Radioanalytical and Nuclear Chemistry》2017,313(1):93-99
Solvent extraction studies on the purification of uranium from zirconium rich sodium diuranate (SDU) feed was carried out using n-tri butyl phosphate (TBP) as extractant and n-decanol as phase modifier. The presence of Zr in SDU leached solution leads to the formation of third phase during liquid–liquid extraction of uranium which was successfully prevented by addition of n-decanol in 30% (v/v) TBP/n-dodecane mixture. A seven stage counter current extraction of SDU feed solution followed by five stage stripping were carried out using optimum concentration of phase modifier 15% n-decanol-30% TBP in n-dodecane as solvent. Based on the findings a process flow-sheet has been developed for the purification of SDU to nuclear grade ammonium diuranate. 相似文献
18.
K. Shakir Sh. G. Beheir M. Aziz 《Journal of Radioanalytical and Nuclear Chemistry》1992,162(2):371-380
The effect of added TBP on the extraction of uranium(VI) with a solution of di-(2-ethylhexyl)-phosphoric acid (HDEHP) in o-dichlorobenzene from nitric acid solutions has been investigated at varying concentrations of nitric acid, HDEHP, TBP and uranium(VI). The mechanism of the synergistic effect of TBP is discussed on the basis of the results and can be summarized in the following equation: UO
2(aq)
2+
+0.67(HX)3(o)+2TBP(o)UO2X2·2TBP(o)+2H
(aq)
+
where HX denotes HDEHP and the HDEHP loaded on the foam is trimerized. 相似文献
19.
Ying-Mao Chen 《中国化学会会志》1966,13(2):82-89
Extraction study on polonium from large amounts of irradiated bismuth was made with diluted TBP solution. Polonium used in this work was Po-210, which was prepared by the irradiation of bismuth according to the following nuclear reaction, . From this study the following extraction conditions were obtained.
- (1) Extraction from 7 N HCl was found to be most suitable.
- (2) Degree of the dilution of TBP with diluent was studied and TBP concentration at about 10% was found to be most effective.
- (3) With various kinds of the solvent as diluent, the following order of the extraction was found: o-xylene>carbon tetrachloride>benzene>amy1 alcohol>chloroform.
20.
Shen Chaohong Bao Borong Bao Yizhi Wang Gaodong Qian Ju Cao Zhengbei 《Journal of Radioanalytical and Nuclear Chemistry》1994,178(1):91-98
The extracting abilities for thorium, uranium and some fission products by five sulfoxides are given. The results show that di(2-ethylhexyl) sulfoxide (DEHSO) is not only completely miscible with kerosene, but also superior to tri-n-butyl phosphate in some properties. The extraction behavior of uranium, thorium and some fission products such as zirconium, niobium and ruthenium from aqueous nitric acid with DEHSO in kerosene has been studied over a wide range of conditions. DEHSO extracted uranium and fission products better than TBP under all conditions and is similar to TBP in extraction of thorium. A study of extraction mechanism indicates that U and Th are extracted as disolvates, whereas HNO3 is extracted as monosolvate. Extraction of the two actinides decreases with increasing temperature, indicating the extraction to be exothermic. Preliminary studies show that -ray irradiated DEHSO extracts Zr and Nb to a smaller extent than irradiated TBP in the range of 104–107 rad. 相似文献