Synergistic extraction of uranium from acidic sulfate leach liquor using D2EHPA mixed with TOPO

Uranium extraction from sulfate leach liquor acid by D₂EHPA and TOPO mixture in kerosene was investigated. The effect of different factors affecting the extraction mechanism such as sulfate leach liquor acid, D₂EHPA and TOPO concentrations and temperature have been studied. The mathematical treatment for the obtained date suggested that the composition of synergistic extraction species is (UO₂(D)₂T). The logarithm of the apparent equilibrium constant, log Kex, of synergistic extraction reaction has been evaluated, to be 3.35 ± 0.1. The effect of temperature on extraction process was investigated and the apparent values of the thermodynamics parameters (?H, ?G and ?S) were 38.2 kJ/mol, ?19.1 kJ/mol and 192.5 J/mol respectively.     

Removal of uranium from sulfate leach liquor of salcrete deposits using tri-n-octyl amine

A uranyl sulfate leach liquor obtained by uranium leaching of a technological sample of salcrete deposits of Gabal Qatrani ore was subjected to uranium extraction using the liquid–liquid technique. Uranium was effectively extracted from sulfate leach liquor by [(10 %) tri-n-octylamine (TOA)] dissolved in xylene as a diluent. The extraction efficiency was markedly enhanced as the concentration of TOA increases from 1 to 10 %. The relevant factors controlling the extraction process of uranium using tri-n-octylamine were studied. These factors include the effect of diluents used, TOA concentration, contact time, settling time and phase ratio (O/A) v/v. The optimum extraction conditions were chosen. Stripping of uranium from the loaded TOA has been carried out using 5 % Na₂CO₃ as an effective stripping agent. More than 97 % of uranium was extracted by 10 % TOA, at contact time 10 min, settling time 5 min, phase ratio (V_O/V_A) 1/1 and at room temperature. The feasibility of using the TOA for preconcentration-separation of uranium was assessed by stripping studies. The loaded uranium onto TOA has been stripped by 100 % when using 5 % Na₂CO₃ as an efficient eluting agent at 15 min contact time, 5 min settling time and phase ratio (O/A) 2/1.     

Experimental study on the uranium(VI) extraction rate and droplet mass transfer coefficients from a sulfate leach liquor medium with Alamine 336 in a single drop column

Journal of Radioanalytical and Nuclear Chemistry - The mass transfer coefficient and the extraction degree of uranium was investigated from a leach liquor by Alamine 336 in a single drop column....     

Solvent extraction of uranium(VI) and separation of vanadium(V) from sulfate solutions using Alamine 336

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 H₂SO₄) 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.     

A Study on the extraction of uranium(VI) from sulphate leach liquor using LIX63

The sulphate leach liquor obtained from the sulphuric acid leaching process of Egyptian monazite was treated using solvent extraction to recover U(VI) by LIX63. The influence of various basic variables such as pH, concentration of LIX63, temperature, different stripping agent, phase ratio and diluents was examined. Using 10% LIX63 with the aqueous solution at equilibrium pH 5.5 and a phase ratio A/O?=?1/1, a four-stage McCabe-Thiele plot was constructed, which showed 85.57% of U(VI) extraction. The thermodynamic data showed that the extraction process is exothermic with enthalpy change ΔH?=???43.866?kJ/mol, the stripping of U(VI) was quantitative using 4?M HNO₃. The stable complex UO₂(HSO₄)R_org formed during extraction which supports the cation exchange mechanism was confirmed by FTIR spectral analysis. Uranium cake was finally obtained from the strip solution by the addition of hydrogen peroxide and ammonium hydroxide as precipitating agents, and a workable flowsheet was then formulated.     

Anomalous behavior of radioiodine: Solvent extraction from acidic solution

Anomalous behavior of radioiodine was found in solvent extraction. Iodine was extracted into CS₂ from acidic solution over a wide range of iodine concentration. The distribution ratio was obtained by measuring the -rays from iodine-131. The ratio drastically changed at about 10^–5 mol l^–1. The change is readily explained by the kinetic behavior of radioiodine.     

Uranium(VI) recovery from acidic leach liquor using manganese oxide coated zeolite (MOCZ) modified with amine

Journal of Radioanalytical and Nuclear Chemistry - Manganese oxide coated zeolite modified with trioctyl amine (MOCZ/TOA) was tested for adsorption of uranium. Different experiments were performed...     

Solvent extraction of uranium(VI) with DI-2-ethylhexyldithiophosphoric acid from aqueous nitrate,chloride, sulfate and phosphate media

The extraction of uranium(VI) with di-2-ethylhexyldithiophosphoric acid (HEhdtp) in benzene from aqueous solutions containing nitrate, chloride, sulfate and phosphate anions was investigated. The data obtained show hat the mechanism of extraction is similar to that established for perchlorate media. The inorganic anions present in the aqueous phase do not participate in the extraction process but affect the magnitude of the distribution ratio by the complexation phenomena which occur in the aqueous phase. In benzene the extracted species is a 12 complex of uranium(VI) with HEhdtp.     

Solvent extraction studies of cobalt in aqueous thiocyanate solutions using Aliquat-336

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

     

13.

Solvent extraction of yttrium(III) by TBP from acidic organic-aqueous solutions     

L. Rosický  J. Hála 《Journal of Radioanalytical and Nuclear Chemistry》1983,80(1-2):43-48

Extraction by benzene solutions of TBP of carrier-free⁹⁰Y(III) from mixed aqueous-organic nitrate and perchlorate solutions was studied with special respect to the S-shaped D_Y versus acid concentration plots observed in aqueous systems. The presence of organic solvents in the aqueous phase enhanced the extraction of Y(III) and also influenced the shape of the D_Y vs. acid concentration plots in that the minimum was shifted towards lower acid concentration, became less pronounced, and eventually vanished completely.     

14.

Liquid-liquid extraction of uranium(VI) by Cyanex 301/alamine 308 and their mixtures with TBP/DDSO     

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).     

15.

Deactivation of the scandium concentrate recovered from uranium leach liquors     

Vladimir N. Rychkov  Vladimir S. Semenishchev  Maxim A. Mashkovtsev  Evgeny V. Kirillov  Sergey V. Kirillov  Grigory M. Bunkov  Maxim S. Botalov 《Journal of Radioanalytical and Nuclear Chemistry》2016,310(3):1247-1253

     

16.

Solvent extraction and spectrophotometric determination of uranium (VI)     

Badri V. Agarwal  Satendra P. Sangal  Arun K. Dey 《Fresenius' Journal of Analytical Chemistry》1965,207(4):256-259

Summary Solvent extraction of uranium-sodium diethyldithiocarbamate with ethylmethyl ketone and separation from titanium, zirconium, thorium, lanthanum and cerium has been described. It has been found that 11.75 to 47.00 mg of uranium can be extracted from a binary mixture containing 4.78 to 19.04 mg of titanium, 9.12 to 36.48 mg of zirconium, 116.0 to 460.0 mg of thorium, 6.95 to 27.8 mg of lanthanum or 7.06 to 28.24 mg of cerium at pH 3.0. The pH range between which the separations may be carried out successfully is 2.0 to 3.5. The following cations interfere in the separations: Cu^II, Fe^III, Co^II, Bi^III, Ni^II, Cr^VI, Te^IV, Se^IV, Ag^I, Hg^II, As^III, Sn^IV, Pb^IV, Cd^II, Mo^VI, Mn^II, V^V, Zn^II, In^III, Tl^I, W^VI, Os^VIII and Nb^V.

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Zusammenfassung Uran kann durch Extraktion als Diäthyldithiocarbamidat mit Methyläthylketon von Ti, Zr, Th, La oder Ce getrennt werden. Der günstigste pH-Bereich liegt zwischen 2,0 und 3,5. Die Trennungen wurden mit folgenden Mengen durchgeführt: U (11,75–47,00 mg); Ti (4,78 bis 19,04 mg), Zr (9,12–36,48 mg) Th (116,0–460,0 mg), La (6,95–27,8 mg), Ce (7,06–28,24 mg). Folgende Ionen verursachen Störungen: Cu^II, Fe^III, Co^II, Bi^III, Ni^II, Cr^VI, Te^IV, Se^IV, Ag^I, Hg^II, As^III, Sn^IV, Pb^IV, Cd^II, Mo^VI, Mn^II, V^VI, Zn^II, In^III, Tl^I, W^VI, Os^VIII sowie Nb^V.

     

17.

Study of scandium and thorium sorption from uranium leach liquors     

Alexey L. Smirnov  Svetlana M. Titova  Vladimir N. Rychkov  Grigory M. Bunkov  Vladimir S. Semenishchev  Eugeny V. Kirillov  Nikolay N. Poponin  Ilya A. Svirsky 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(2):277-283

Scandium and thorium sorption from simulated uranium leach liquors by phosphorous containing ion exchange resins was studied. Increase of thorium concentration resulted in a decrease of scandium sorption by 26–65%. Tulsion CH 93 resin was chosen for Sc separation from uranium leach liquors. It was shown that 180 g L^?1 Na₂CO₃ allowed for elution 94.1% of Sc and 98.9% of Th in dynamic conditions. Using (NH₄)₂SO₄ (50 g L^?1) + ACBM (180 g L^?1) mixture for primary Sc/Th separation at the resin/eluent ratio of 1:5 resulted in thorium desorption degree as high as 66–69%, whereas scandium loss did not exceed 10%.     

18.

Solvent extraction separation of uranium(VI) with dibenzo-24-crown-8     

B. S. Mohite  J. M. Patil  D. N. Zambare 《Journal of Radioanalytical and Nuclear Chemistry》1993,170(1):215-224

Uranium(VI) was quantitatively extracted with 0.01M DB-24-crown-8 in nitrobenzene from 6 to 10M hydrochloric acid. From the organic phase uranium was stripped with 2M nitric acid and determined spectrophotometrically with PAR at 530 nm. Uranium(VI) was separated from a large number of elements in binary mixtures as well as from multicomponent mixtures. The method was extended to the analysis of uranium in geological samples and animal bone.     

19.

An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media   总被引：1，自引：0，他引：1  

Dietz ML  Horwitz EP  Sajdak LR  Chiarizia R 《Talanta》2001,54(6):1173-1184

The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923^® (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925^®, due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k′ values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO₃. The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.     

20.

Automatic analysis of uranium-bearing extracts in amine solvent extraction plants processing sulfate leach liquors     

Samuel J. Lyle  Massoud Tamizi 《Fresenius' Journal of Analytical Chemistry》1984,318(8):599-603

Summary Instrumentation based on continuous segmented flow analysis is suggested for the control of uranium loading in the amine phase of solvent extraction plants processing sulfate leach liquors. It can be installed with relatively little capital outlay and operational costs are expected to be low. The uranium(VI) in up to 60 samples of extract (0.1 to 5 g l^–1 U) per hour can be determined. Application of spectrophotometry to the analysis of various process streams is discussed and it is concluded that it compares favourably in several important respects with the use of alternative techniques.

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Automatische Analyse uranhaltiger Extrakte bei der Verarbeitung aminhaltiger Sulfatlaugen

Zusammenfassung Die vorgeschlagene Kontrolle der Uranbelastung beruht auf der Durchflußanalyse mit kontinuierlicher Segmentierung. Der Aufwand ist relativ gering und auch die Betriebskosten sind niedrig. Uran(VI) kann in bis zu 60 Proben je Stunde (0,1–5 g/l U) bestimmt werden. Die Anwendung der Spektralphotometrie für die Analyse verschiedener Prozeßströme wird diskutiert. In mehrfacher Hinsicht ist das Verfahren mit anderen Methoden gut vergleichbar.

     

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

Solvent extraction of yttrium(III) by TBP from acidic organic-aqueous solutions

Extraction by benzene solutions of TBP of carrier-free⁹⁰Y(III) from mixed aqueous-organic nitrate and perchlorate solutions was studied with special respect to the S-shaped D_Y versus acid concentration plots observed in aqueous systems. The presence of organic solvents in the aqueous phase enhanced the extraction of Y(III) and also influenced the shape of the D_Y vs. acid concentration plots in that the minimum was shifted towards lower acid concentration, became less pronounced, and eventually vanished completely.     

Liquid-liquid extraction of uranium(VI) by Cyanex 301/alamine 308 and their mixtures with TBP/DDSO

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).     

Solvent extraction and spectrophotometric determination of uranium (VI)

Summary Solvent extraction of uranium-sodium diethyldithiocarbamate with ethylmethyl ketone and separation from titanium, zirconium, thorium, lanthanum and cerium has been described. It has been found that 11.75 to 47.00 mg of uranium can be extracted from a binary mixture containing 4.78 to 19.04 mg of titanium, 9.12 to 36.48 mg of zirconium, 116.0 to 460.0 mg of thorium, 6.95 to 27.8 mg of lanthanum or 7.06 to 28.24 mg of cerium at pH 3.0. The pH range between which the separations may be carried out successfully is 2.0 to 3.5. The following cations interfere in the separations: Cu^II, Fe^III, Co^II, Bi^III, Ni^II, Cr^VI, Te^IV, Se^IV, Ag^I, Hg^II, As^III, Sn^IV, Pb^IV, Cd^II, Mo^VI, Mn^II, V^V, Zn^II, In^III, Tl^I, W^VI, Os^VIII and Nb^V.

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Zusammenfassung Uran kann durch Extraktion als Diäthyldithiocarbamidat mit Methyläthylketon von Ti, Zr, Th, La oder Ce getrennt werden. Der günstigste pH-Bereich liegt zwischen 2,0 und 3,5. Die Trennungen wurden mit folgenden Mengen durchgeführt: U (11,75–47,00 mg); Ti (4,78 bis 19,04 mg), Zr (9,12–36,48 mg) Th (116,0–460,0 mg), La (6,95–27,8 mg), Ce (7,06–28,24 mg). Folgende Ionen verursachen Störungen: Cu^II, Fe^III, Co^II, Bi^III, Ni^II, Cr^VI, Te^IV, Se^IV, Ag^I, Hg^II, As^III, Sn^IV, Pb^IV, Cd^II, Mo^VI, Mn^II, V^VI, Zn^II, In^III, Tl^I, W^VI, Os^VIII sowie Nb^V.

     

Study of scandium and thorium sorption from uranium leach liquors

Scandium and thorium sorption from simulated uranium leach liquors by phosphorous containing ion exchange resins was studied. Increase of thorium concentration resulted in a decrease of scandium sorption by 26–65%. Tulsion CH 93 resin was chosen for Sc separation from uranium leach liquors. It was shown that 180 g L^?1 Na₂CO₃ allowed for elution 94.1% of Sc and 98.9% of Th in dynamic conditions. Using (NH₄)₂SO₄ (50 g L^?1) + ACBM (180 g L^?1) mixture for primary Sc/Th separation at the resin/eluent ratio of 1:5 resulted in thorium desorption degree as high as 66–69%, whereas scandium loss did not exceed 10%.     

Solvent extraction separation of uranium(VI) with dibenzo-24-crown-8

Uranium(VI) was quantitatively extracted with 0.01M DB-24-crown-8 in nitrobenzene from 6 to 10M hydrochloric acid. From the organic phase uranium was stripped with 2M nitric acid and determined spectrophotometrically with PAR at 530 nm. Uranium(VI) was separated from a large number of elements in binary mixtures as well as from multicomponent mixtures. The method was extended to the analysis of uranium in geological samples and animal bone.     

An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media

The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923^® (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925^®, due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k′ values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO₃. The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.     

Automatic analysis of uranium-bearing extracts in amine solvent extraction plants processing sulfate leach liquors

Summary Instrumentation based on continuous segmented flow analysis is suggested for the control of uranium loading in the amine phase of solvent extraction plants processing sulfate leach liquors. It can be installed with relatively little capital outlay and operational costs are expected to be low. The uranium(VI) in up to 60 samples of extract (0.1 to 5 g l^–1 U) per hour can be determined. Application of spectrophotometry to the analysis of various process streams is discussed and it is concluded that it compares favourably in several important respects with the use of alternative techniques.

---

Automatische Analyse uranhaltiger Extrakte bei der Verarbeitung aminhaltiger Sulfatlaugen

Zusammenfassung Die vorgeschlagene Kontrolle der Uranbelastung beruht auf der Durchflußanalyse mit kontinuierlicher Segmentierung. Der Aufwand ist relativ gering und auch die Betriebskosten sind niedrig. Uran(VI) kann in bis zu 60 Proben je Stunde (0,1–5 g/l U) bestimmt werden. Die Anwendung der Spektralphotometrie für die Analyse verschiedener Prozeßströme wird diskutiert. In mehrfacher Hinsicht ist das Verfahren mit anderen Methoden gut vergleichbar.