Microviscosity of ions and salting-out in the extraction of rare-earth and transplutonium elements

1989 ◽  
Vol 131 (1) ◽  
pp. 111-119 ◽  
Author(s):  
B. Gorski ◽  
N. Gorski ◽  
Chr Winde
Keyword(s):  
Rare Earth ◽  
Salting Out ◽  
Transplutonium Elements

A method for selective separation of scandium (III) from yttrium and a number of rare-earth elements for its subsequent determination

2018 ◽  
Vol 84 (11) ◽  
pp. 23-27
Author(s):  
M. I. Degtev ◽  
A. A. Yuminova ◽  
A. S. Maksimov ◽  
A. P. Medvedev
Keyword(s):  
Rare Earth ◽  
Aqueous Phase ◽  
Selective Isolation ◽  
Optimum Ratio ◽  
Extraction Condition ◽  
Sulfosalicylic Acid ◽  
Salting Out ◽  
Subsequent Determination ◽  
Toxic Organic Solvents ◽  
Metal Ions Extraction

The possibility of using an aqueous stratified system of antipyrine — sulfosalicylic acid — water for the selective isolation of scandium macro- and microquantities for subsequent determination is studied. The proposed extraction system eliminates the usage of toxic organic solvents. The organic phase with a volume of 1.2 to 2.0 ml, resulting from delamination of the aqueous phase containing antipyrine and sulfosalicylic acid is analysed to assess the possibility of using such systems for metal ions extraction. Condition necessary for the formation of such a phase were specified: the ratio of the initial components, their concentration, presence of inorganic salting out agents. The optimum ratio of antipyrine to sulfosalicylic acid is 2:1 at concentrations of 0.6 and 0.3 mol/liter in a volume of the aqueous phase of 10 ml. The obtained phase which consists of antipyrinium sulfosalicylate, free antipyrine and water, quantitatively extracts macro- and microquantities of scandium at pH = 1.54. Macro- and microquantities of yttrium, terbium, lanthanum, ytterbium and gadolinium are not extracted under the aforementioned conditions thus providing selective isolation of scandium from the bases containing yttrium, ytterbium, terbium, lanthanum, and gadolinium.

Oxidative digestion of spent sulfocationites containing radioactive rare earth and transplutonium elements

2020 ◽  
Vol 325 (2) ◽  
pp. 667-671
Author(s):  
V. V. Milyutin ◽  
O. V. Kharitonov ◽  
L. A. Firsova ◽  
N. N. Nekrasova ◽  
E. A. Kozlitin
Keyword(s):  
Rare Earth ◽  
Transplutonium Elements

Use of complexones for the extraction separation of rare earth and transplutonium elements with amines

1979 ◽  
Vol 51 (1) ◽  
pp. 27-46 ◽  
Author(s):  
A. A. Kopyrin ◽  
V. D. Murashov ◽  
V. D. Demidov ◽  
V. P. Shvedov
Keyword(s):  
Rare Earth ◽  
Transplutonium Elements ◽  
Extraction Separation

scholarly journals Solubility of Rare Earth Chlorides in Ternary Water-Salt Systems in the Presence of a Fullerenol—C60(OH)24 Nanoclusters at 25 °C. Models of Nonelectrolyte Solubility in Electrolyte Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 349
Author(s):  
Nikolay A. Charykov ◽  
Viktor A. Keskinov ◽  
Kirill A. Tsvetkov ◽  
Ayat Kanbar ◽  
Konstantin N. Semenov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Pure Water ◽  
Pitzer Model ◽  
Ternary Systems ◽  
Electrolyte Solutions ◽  
Water Soluble ◽  
Salting Out ◽  
Isothermal Saturation ◽  
Water Salt ◽  
Salt Systems

The solubility in triple water-salt systems containing NdCl3, PrCl3, YCl3, TbCl3 chlorides, and water-soluble fullerenol C60(OH)24 at 25 °C was studied by isothermal saturation in ampoules. The analysis for the content of rare earth elements was carried out by atomic absorption spectroscopy, for the content of fullerenol—by electronic spectrophotometry. The solubility diagrams in all four ternary systems are simple eutonic, both consisting of two branches, corresponding to the crystallization of fullerenol crystal-hydrate and rare earth chloride crystal-hydrates, and containing one nonvariant point corresponding to the saturation of both solid phases. On the long branches of C60(OH)24*18H2O crystallization, a C60(OH)24 decreases by more than 2 orders of magnitude compared to the solubility of fullerenol in pure water (salting-out effect). On very short branches of crystallization of NdCl3*6H2O, PrCl3*7H2O, YCl3*6H2O, and TbCl3*6H2O, the salting-in effect is clearly observed, and the solubility of all four chlorides increases markedly. The four diagrams cannot be correctly approximated by the simple one-term Sechenov equation (SE-1), and very accurately approximated by the three-term modified Sechenov equation (SEM-3). Both equations for the calculation of nonelectrolyte solubility in electrolyte solutions (SE-1 and SEM-3 models) are obtained, using Pitzer model of virial decomposition of excess Gibbs energy of electrolyte solution. It is shown that semi-empirical equations of SE-1 and SEM-3 models may be extended to the systems with crystallization of crystal-solvates.

Separation of rare-earth and transplutonium elements by displacement chromatography on S-957 phosphonic ion exchanger

2012 ◽  
Vol 54 (2) ◽  
pp. 164-167 ◽  
Author(s):  
Yu. B. Shumilova ◽  
V. M. Gelis ◽  
V. V. Milyutin ◽  
O. V. Kharitonov ◽  
L. A. Firsova
Keyword(s):  
Rare Earth ◽  
Ion Exchanger ◽  
Displacement Chromatography ◽  
Transplutonium Elements

scholarly journals EXTRACTION OF RARE-EARTH ELEMENTS BY MIXES OF ISOMERS OF TRIBUTYLPHOSPHATE WITH NITRATE TRIALKYLMETHYLAMMONIUM

2018 ◽  
Vol 61 (7) ◽  
pp. 55
Author(s):  
Alexander V. Val'kov ◽  
Nadezhda D. Khmelevskaya
Keyword(s):  
Rare Earth ◽  
Synergistic Effect ◽  
Rare Earth Elements ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Constant Composition ◽  
Salting Out ◽  
Isomolar Series ◽  
Variable Concentration ◽  
Gadolinium Nitrate

Results of studying of extraction of nitrates of rare-earth elements (REE) and trialkylmetylammoniya nitrate (TAMAN) are given by mixes of isomers of tributyl phosphate (TBP). Tri-iso-butylphosphate and tri - sec-butylphosphate are investigated as isomers of normal tributylphosphate. The water phase contained 8 mol/dm3 nitrate of ammonium and 5.10-4 mol/dm3 of neodymium nitrate at рН = 2-3. The content of extractants in isomolar series was varied in the range of 0-0.3 mol/dm3. It was established that synergistic effect decreases in a series of TBP> TIBP> TvtBP. Synergistic effect is calculated as the distribution coefficient relation at extraction by mix of extractants to the sum of coefficients of distribution at extraction by each of extractants. Synergistic effect reaches its maximum value at the ratio: [NPOC] : [TAMAN] = 2 : 1 for TBP and 4-5 : 1 for TiBP, TvtBP, and the absolute value fluctuates within 10-50 at extraction of microconcentration of REE. It is noted that the method of isomolar series is applied incorrectly in many researches with the violation of the fundamental requirements (variable concentration of rare earth metals and acid in the aqueous phase, an assumption of a possibility of simultaneous existence of several solvate, variable concentration of salting-out owing to extraction into the organic phase, the association and polymerization in the organic phase, etc..), which must be followed when using this method. Мultiple saturation method (MSM) is offered for a correct application of the method of isomolar series. The method consists in the fact that the organic phase is saturated repeatedly (5-6 times) with the original aqueous solution until a constant composition of the aqueous phase at all points of  isomolar series. It is possible to believe that the organic phase is responsible for the deviation from the additivity in this case. It was established that synergistic effect tends to unity or virtually disappears in the extraction of REE macroamounts method of ofisomolar series of multiple saturation. It is shown that value of synergistic effect approaches unity at gadolinium nitrate extraction by isomolar mix in the MSM mode. Synergistic effect for a mixture of rare earth elements is close to unity in the extraction of REE mixtures macroamounts of TiBP and TAMAN, and the individual elements are distributed in accordance with the extraction characteristics of each of the extractants alone: synergistic effect for several elements of cerium is greater than one, and yttrium - somewhat less than one. It is suggested that if there is free extragent the formation of mixed solvate may be explained by the steric effect, which disappears at saturation of extracgent.Forcitation:Val'kov A.V., Khmelevskaya N.D. Extraction of rare-earth elements by mixes of isomers of tributylphosphate with nitrate trialkylmethylammonium. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 54-60

Sign in / Sign up

Export Citation Format

Share Document