共查询到20条相似文献,搜索用时 15 毫秒
1.
Sun Guo-Xin Cui Yu Han Jing-Tian Shao Hua Bao Bo-Rong 《Journal of Radioanalytical and Nuclear Chemistry》2000,246(2):431-432
The extraction of U(VI) from nitric acid solutions with di-(1-methylheptyl) phosphoric acid has been investigated. The dependence on nitric acid concentration, DMHPA concentration and temperature has been considered and the infra-red spectra of extracted species and extractant were recorded. The mechanism of extraction is discussed in the light of the results obtained. 相似文献
2.
Yang Yan-Zhao Sun Si-Xiu Zhang Lei Yang Yong-Hui Bao Bo-Rong 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(1):383-385
The liquid-liquid extraction of uranium(VI) from aqueous nitric acid with bis(octylsulfinyl)methane (BOSM) has been studied
over a wide range of conditions. The extracted species appear to be UO2(NO3)2·2BOSM. It was found that the extraction increased with increasing nitric acid concentration up to 8.5 mol/l and then descreased.
Extraction also increased with increasing extractant concentration. The influence of temperature and salting-out agent concentration
on the extraction equilibrium has also been investigated, and the enthalpy of the extraction reaction was estimated. 相似文献
3.
You-Shao Wang Guo-Xin Sun De-Feng Xie Bo-Rong Bao Wei-Guo Cao 《Journal of Radioanalytical and Nuclear Chemistry》1996,214(1):67-76
A new symmetrical diamide, the straight-chain alakyl substituted neutral tetrabutyladipicamide (TBAA) has been synthesized, characterized and used for the extraction of U(V) and Th(IV) from nitric acid solutions in a diluent composed of 50% 1,2,4-trimethylbenzene (TMB) and 50% kerosene (OK). Extraction distribution coefficients of U(VI) and Th(IV) as a function of aqueous nitric acid concentration, extractant concentration and temperature have been studied. Back-extraction of U(VI) and Th(IV) from organic phases by dilute nitric acid has been undertaken. From the data, the compositions of extracted species, equilibrium constants and enthalpies of extraction reactions have also been calculated. 相似文献
4.
The liquid-liquid extraction of uranium(VI) from aqueous nitric acid with n-octyldecylsulfoxide (ODSO) in toluene has been studied over a wide range of conditions. The extracted species appears to be UO2(NO3)2·2ODSO. The extraction increased with increasing nitric acid concentration up to 2.0 mol/l and then decreased. Extraction also increased with increasing extractant concentration. The influence of temperature, salting-out agent concentration and complex anion concentration on the extraction equilibrium were also investigated, and the enthalpy of the extraction reaction was calculated. 相似文献
5.
Yang Yan-Zhao Sun Si-Xiu Yang Yong-Hui Zhang Lei Yu Shao-Ning Bao Bo-Rong 《Journal of Radioanalytical and Nuclear Chemistry》1999,241(1):231-234
The synergic extraction of uranium(VI) from nitric acid solution with petroleum sulfoxides (PSO) and tri-n-butyl phosphate (TBP) mixture has been studied. It has been found that maximum synergic extraction effect occurs if the molar
ratio of PSO to TBP is two to three. The composition of the complex of synergic extraction is UO2(NO3)2·TBP·PSO. The formation constant of the complex isK
PT=8.19. The effect of extractant concentration, nitric acid concentration, salting-out agent concentration and temperature
on the extraction equilibrium of uranium(VI) was also studied. 相似文献
6.
The extraction of uranium(VI) with bis(hexylsulfinyl)methane (BHxSM) from nitric acid aqueous solution has been investigated. It was found that the extraction increased with increasing nitric acid concentration up 8.5 mol/l and then decreased. Extraction distribution ratio also increased with the bis(hexylsulfinyl)methane concentration. The extraction species appear to be UO2(NO3)2
.2BHxSM. The influences of temperature, salting-out concentration and oxalate concentration on the extraction equilibrium were also investigated, and the enthalpy of the extraction reaction was obtained. The result shows that the reaction of uranium(VI) extraction with BHxSM is an exothermic one. 相似文献
7.
Yang Yan-Zhao Yang Yong-Hui Xong Jun Sun Si-Xiu Bao Bo-Rong 《Journal of Radioanalytical and Nuclear Chemistry》1999,241(1):235-238
The liquid-liquid extraction behavior of uranium(VI) from aqueous nitric acid with bis(octylsulfinyl)ethane (BOSE) in 1,1,2,2-tetrachloroethane
has been studied over a wide range of conditions. The extracted species appears to be UO2(NO3)2·2BOSE. It was found that the extraction increases with increasing nitric acid concentration up to 7 mol/l and then decreased.
Extraction also increases with increasing extractant concentration. The influence of temperature and salting-out agent concentration
on the extraction equilibrium and stripping of uranium(VI) was also investigated and the enthalpy of the extraction reaction
was obtained. 相似文献
8.
K. A. Venkatesan B. Robert Selvan M. P. Antony T. G. Srinivasan P. R. Vasudeva Rao 《Journal of Radioanalytical and Nuclear Chemistry》2005,266(3):431-440
Summary Commercially available polystyrene-divinylbenzene (PS-DVB) resins functionalized with isothiouronium (Tulsion CH-95), phosphinic
acid (Tulsion CH-96) and methylene thiol (Tulsion CH-97) moieties have been used for separating palladium from nitric acid
medium. Extraction of palladium has been studied as a function of time, concentration of nitric acid and palladium. The distribution
coefficients (Kd, ml/g) of palladium on sulfur based resins (Tulsion CH-95 and Tulsion CH-97) are higher (5000-104ml/g in 0.1M nitric acid) than on Tulsion CH-96 resin and decrease with increasing concentration of nitric acid. The initial
rate of extraction of palladium by Tulsion CH-95 and Tulsion CH-97 resins was very rapid and the time required for the establishment
of equilibrium was a function of palladium concentration in the aqueous phase. The rate data could be fitted by a second order
rate equation and the magnitude of rate constant for the extraction of palladium by these resins (~102M-1. min-1) decreased in the order of: Tulsion CH-95 > Tulsion CH-97 > Tulsion CH-96. The extraction isotherms of Tulsion CH-95 were
fitted by Langmuir adsorption model and the coefficients were obtained by regression. The extraction capacity of palladium
on Tulsion CH-95 was found to be ~20 mg/g at 3M nitric acid. Column experiments have been conducted and the data were fitted
using Thomas model. A column utilization of 75% was achieved for the extraction of palladium by Tulsion CH-95 resin. 相似文献
9.
Yang Xing-Lu Bao Bo-Rong Zhou Fang Cao Wei-Guo Li Yu-Lan 《Journal of Radioanalytical and Nuclear Chemistry》2001,250(3):573-575
A novel extractant, N, N-didecanoylpiperazine (DDPEZ), was synthesized for the first time. The extraction of U(VI) by DDPEZ from aqueous nitric acid media in carbon tetrachloride has been studied. The dependence of extraction distribution ratio on concentration of aqueous nitric acid, extractant, salting-out agent and temperature was investigated and the enthalpy of the extraction was calculated. 相似文献
10.
D. Cvjetićanin N. Cvjeticanin M. Pravica Ž. Knežević 《Journal of Radioanalytical and Nuclear Chemistry》1978,45(2):349-356
The extraction of trivalent iron in the ionic and colloidal states from diluted nitric acid solutions with di-n-butylphosphoric
acid in cyclohexane has been studied. Depending on the concentration of di-n-butylphosphoric and nitric acid, the ionic and
colloidal trivalent iron can be distributed between the solvent, aqueous phase and solvent-aqueous interface. 相似文献
11.
Yang Xing-Cun Bao Bo-Rong Cao Wei-Gou Sun Guo-Xin Li Zhen 《Journal of Radioanalytical and Nuclear Chemistry》2001,250(3):559-561
A novel extractant, N,N-dilauroylpiperazine (DLPEZ), was synthesized for the first time. The extraction of uranium(VI) with the novel extractant in carbon tetrachloride from aqueous nitric acid media has been studied. The dependence of extraction distribution ratio on the concentration of aqueous nitric acid, extractant, salting-out agent and temperature was investigated and the enthalpy of the extraction was determined. 相似文献
12.
K. A. Venkatesan K. V. Shyamala M. P. Antony T. G. Srinivasan P. R. Vasudeva Rao 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(3):563-570
Batch and dynamic extractions of uranium(VI) in 10−3–10−2M concentrations in 3–4M nitric acid medium have been investigated using a commercially available phosphinic acid resin (Tulsion
CH-96). The extraction of uranium(VI) has been studied as a function of time, batch factor (V/m), concentrations of nitric acid and uranium(VI) ion. Dual extraction mechanism unique to phosphinic acid resin has been established
for the extraction of uranium(VI). Distribution coefficient (K
d
) of uranium(VI) initially decreases with increasing concentration of nitric acid, reaches a minimum value at 1.3M, followed
by increases in K
d
. A maximum K
d
value of ∼2000 ml/g was obtained at 5.0M nitric acid. Batch extraction data has been fitted into the linearized Langmuir
adsorption isotherm. The performance of the resin under dynamic extraction conditions was assessed by following the breakthrough
behavior of the system. Effect of flow rate, concentrations of nitric acid and uranium ion in the feed on the breakthrough
behavior of the system was studied and the data was fitted using Thomas model. 相似文献
13.
Asha Jain O. V. Singh S. N. Tandon 《Journal of Radioanalytical and Nuclear Chemistry》1991,147(2):355-361
Mono-(2-ethylhexyl)phosphoric acid (H2MEHP) has been used to study the extraction of some lanthanoids and other associated elements from nitric acid medium. Effect of various variables like kind of diluent, concentration of metal ion, nitric acid and extractant has been investigated. Based on distribution data, it was possible to achieve some separations of lighter lanthanoids from metals like titanium, zirconium, thorium and uranium with high separation factors. 相似文献
14.
Bao Bo-Rong Bao Ya-Zhi Shen Chao-Hong Wang Gao-Dong Qian Jun Cao Zheng-Bai 《Journal of Radioanalytical and Nuclear Chemistry》1992,162(2):391-398
A study on solvent extraction of U(VI), Th(IV) and HNO3 from nitric acid media by DEHSO is described. Extraction coefficients of U(VI), Th(IV) and HNO3 as a function of aqueous HNO3 concentration, extractant concentration and temperature have been studied. From the data the compositions of extracted species, equilibrium constants and enthalpies of extraction reaction have been evaluated. Back-extraction of U(VI) and Th(IV) from the organic phase by dilute nitric acid has also been tested. All studies on DEHSO are compared with TBP. 相似文献
15.
The distribution of acid, water, methanol, ethanol and acetone between mixed aqueous-organic nitric acid solutions and solutions
of trilaurylammoniumnitrate in cyclohexane has been investigated. The distribution of acid rises with increasing concentrations
of nitric acid, methanol, ethanol and acetone in the mixed aqueous-organic phase. The effect of the organic additives in increasing
the distribution of the acid is methanol<ethanol<acetone. The concentration of nitric acid in the organic phase can be calculated
by a formula similar to that describing the extraction from pure aqueous solutions. The distribution curves of water, methanol
and ethanol resemble each other, all of them showing a minimum, when the distribution ration is plotted versus the nitric
acid concentration in the mixed aqueous-organic phase. The acetone distribution decreases steadily with increasing nitric
acid concentration. The shape of the curves is briefly discussed.
相似文献
16.
The extraction of copper(II) from strongly acidic solution (0.01-8M hydrochloric and 0.01-5M nitric acid) with ammonium 1-pyrrolidinecarbodithioate in di-isobutyl ketone has been studied. Compared with the hydrochloric acid system, a considerably larger amount of the reagent is needed for complete extraction of copper chelate from nitric acid solution as the extract is more unstable in the nitric acid system. The decomposition of copper chelates extracted from nitric acid is based on the oxidation of the reagent and the chelate; the spectral change of the extract from nitric acid suggests that the copper(II) chelate is initially oxidized to copper(II) and then decomposes. The upper limit of the acidity of both acids from which the copper chelate can be quantitatively extracted strongly depends on the reagent concentration; the limit with 8 x 10(-2)M APCD (500-fold reagent: metal molar ratio) was taken as 8 and 4M for hydrochloric and nitric acid, respectively. 相似文献
17.
Y. -S. Wang X. -F. Tan C. -H. Shen B. -R. Bao 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(2):683-686
N,N,N',N'-Tetrabutyladipicamide (TBAA) was used for the extraction of nitric acid and uranyl(II) ion from nitric acid media
into toluene. The effects of nitric acid, uranyl(II) ion, and extractant concentration, temperature and back extraction on
the distribution coefficient of uranyl(II) ion have been studied. The main adduct of TBAA and HNO3 is TBAA·HNO3 in 1.0 mol/l nitric acid solution. The 1:2:2 complex of uranyl(II) ion, nitrate ion and TBAA as extracted species is further
confirmed by IR spectra of the extraction of uranyl(II) ion with TBAA. The values of the thermodynamic parameters have also
been calculated. 相似文献
18.
The influence of acetone on the extraction of Th(IV) and U(VI) from aqueous solutions of nitric acid by solutions of Amberlite
LA-2 and trilaurylamine in cyclohexane has been investigated. The partition of nitric acid and acetone between the two phases
is discussed. The change of the distribution ratios of Th(IV) and U(VI) by adding acetone to the liquid-liquid-system is explained
by the shift of the equilibrium of the metal nitrate complexes and by the increase of the concentration of nitric acid in
the organic phase.
相似文献
19.
M. Draye A. Favre-Réguillon G. Le Buzit J. Foos M. Lemaire A. Guy 《Journal of Radioanalytical and Nuclear Chemistry》1997,220(1):105-107
Thiamacrocycles-synergized sulfonic acid extraction systems have been studied for removing traces of palladium from nitric acid solutions. The influence of the concentration of nitric acid, HDNNS, and thiamacrocycle were studied. Then different thiamacrocycles, with various cavity size and with or without substituent were evaluated. Influences on the extraction and stripping behavior is discussed. 相似文献
20.
M. Ejaz 《Journal of Radioanalytical and Nuclear Chemistry》1977,35(2):341-349
The solvent extraction of cerium(III) from nitric, hydrochloric and sulphuric acid solutions by 4-(5-nonyl)pyridine oxide
and trioctylamine oxide in xylene has been studied. The influence of the concentration of the solvents and salting-out agents
is described. From the results of partition experiments attempts have been made to deduce the nature of the extracted species.
The investigation shows that cerium(III) can be separated from cerium(IV) from very dilute solutions of mineral acids and
also from moderate nitric acid media. 相似文献