Recovery of uranium and thorium from zirconium oxychloride by solvent extraction

Xue-ming, Zhong; Wu, Yuehui

doi:10.1007/s10967-011-1409-z

Cited by 17 publications

(3 citation statements)

References 22 publications

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“…Several methods have been used for separation and purification of thorium from different matrices, including precipitation methods, , chromatographic methods, − supercritical fluid extraction (SFE), , ion exchange resins, − electrochemical methods, , solid phase extraction, − molecular imprinting, − and solvent extraction. − Lack of selective precipitating agents, possibility of losing some of the samples during precipitation and washing, and difficulty of pH adjustment especially in industrial usage are disadvantages of the precipitation methods. The chromatographic and ion exchange methods are time consuming, and furthermore, they do not lead to quantitative separations.…”

Section: Introductionmentioning

confidence: 99%

Separation of Thorium from Zirconium Carbide Waste by Liquid–Liquid Extraction Using Tri-n-octylamine Solvent after Selective Acid Leaching

Nejad

Amini

Ghaziaskar

2020

Ind. Eng. Chem. Res.

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Separation of thorium from zirconium carbide waste is reported. The waste typically contains zirconium, yttrium, uranium, and thorium, along with other impurities including rare earth elements (REEs), iron, calcium, aluminum, hafnium, and titanium. The first step in the separation was selective leaching of zirconium, uranium, and most other impurities with HNO 3 −HF, leaving thorium and REEs as insoluble fluorides. The effective parameters such as HNO 3 and HF concentrations, temperature, and time were optimized for achieving the maximum leaching of zirconium and the minimum leaching of thorium, using central composite design and a multiple response optimization algorithm. Thorium and REEs were leached from the residual solid with H 2 SO 4 , followed by their precipitation with ammonia, dissolution of the precipitate in HNO 3 , and extraction of thorium with tri-noctylamine−kerosene. The factors affecting the extraction of thorium were optimized with respect to HNO 3 , TOA, diluent, V org /V aq , and extraction time. Using the above sample preparation and extraction methods, thorium could be extracted with an efficiency of 95.6%.

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Section: Introductionmentioning

confidence: 99%

Separation of Thorium from Zirconium Carbide Waste by Liquid–Liquid Extraction Using Tri-n-octylamine Solvent after Selective Acid Leaching

Nejad

Amini

Ghaziaskar

2020

Ind. Eng. Chem. Res.

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“…The method of removing U(VI) and Th(IV) in conventional hydrometallurgical processing of rare earths has problems pertaining to the disposal of solid and/or liquid waste, in addition to substantial loss of rare earths to waste (Gui, et al, 2014;Zhu, et al, 2015). For that reason, in the past decade there has been a resurgence of investigations into U(VI) and Th(IV) separation involving the use of different methods (Cheng, et al, 2011;Deng, et al, 2013;Fan, et al, 2011;Gao, et al, 2012;Nasab, et al, 2011;Song, et al, 2009;Zhang, et al, 2012;Zhong & Wu, 2012;Zuo, et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

The effectiveness of ion exchange resins in separating uranium and thorium from rare earth elements in acidic aqueous sulfate media. Part 1. Anionic and cationic resins

Ang

Nikoloski

2017

Hydrometallurgy

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Conventional ion exchange resins with different functional groups were evaluated for their potential application in separating uranium U(VI) and thorium Th(IV) from rare earth elements RE(III). The resins studied comprised strong-and weak-base anion exchange resins, and strong-and weak-acid cation exchange resins. The selectivity of these resins to adsorb U(VI) and Th(IV) in the presence of selected RE(III) was examined in sulfuric acid media of varying concentrations. It was evident that the adsorption performance of the resins was acid concentration-dependent. Most candidate resins had potentially feasible selective adsorption at or below 0.1 mol/L H 2 SO 4 (pH ≥ 0.7). Within the group of anion exchange resins, both the strong-and weak-base resins exhibited a similar selectivity with U(VI) adsorbed in preference to RE(III). The difference between them was their adsorption of Th(IV). The weak-base resin with primary amine functional group demonstrated superior separation of Th(IV) from RE(III). For this resin, 78% of U(VI) and 68% of Th(IV) were adsorbed while RE(III) co-adsorption was less than 5% at 0.0005 mol/L H 2 SO 4 (pH 3). In the case of the strong-acid cation exchange resins, Th(IV) and RE(III) were adsorbed in preference to U(VI), i.e., RE(III) > Th(IV) >> U(VI). The weak-acid cation exchange resins, on the other hand, displayed limited adsorption of all elements.

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“…Recovery and separation of thorium from rare earths is one of the most important tasks in the process of hydrometallurgy and treatment of nuclear fuel. This led to a surge of investigations on thorium separation in the past decade involving the use of different methods and various types of materials based on compositions ranging from inorganic and organic to polymeric species . Attracted by its simplicity and ease of operation, solvent extraction or liquid–liquid extraction has been considered to be a convenient and efficient method for purifying rare earth elements.…”

Section: Introductionmentioning

confidence: 99%

Solvent extraction of thorium(IV) and rare earth elements with novel polyaramide extractant containing preorganized chelating groups

Jiang

Jia

et al. 2013

J of Chemical Tech & Biotech

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BACKGROUND Oligoamides containing intramolecular hydrogen bonds have proved to be excellent extractants for metal cations, but their polymeric counterparts have never been used. Thorium separation from rare earth elements has long been a research subject due to its importance in nuclear energy and metallurgy. In this work a novel polyaramide has been synthesized and investigated for solvent extraction and separation of thorium and rare earths. RESULTS The synthesized polymer 1 [(C32H46N2O6)n], shows a high extractability of 89.4% towards Th(IV) compared with only 36–48% for rare earths. The optimized pH value for extraction of Th(IV) was 3.97. At C1/CM = 2.0, the extraction for Th(IV) reached 95.1%. When adding NaNO3, the separation of Th(IV) from La(III) is more efficient than that from Eu(III) or Yb(III), especially at higher NaNO3 concentration. Th(IV) can be thoroughly stripped from organic phase at 1.50 mol L‐1 HNO3 concentration. CONCLUSION Direct condensation of aromatic diamine and diacid led to a novel polyaramide with introverted chelating groups. Selective extraction of Th(IV) with respect to rare earths was observed and the extraction was an endothermic process. The salting‐out agent and C1/CM ratio can affect the separation efficiency. Thus, the polymer 1 may be a potential candidate for separating thorium and rare earths under specified conditions. © 2013 Society of Chemical Industry

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Recovery of uranium and thorium from zirconium oxychloride by solvent extraction

Cited by 17 publications

References 22 publications

Separation of Thorium from Zirconium Carbide Waste by Liquid–Liquid Extraction Using Tri-n-octylamine Solvent after Selective Acid Leaching

Separation of Thorium from Zirconium Carbide Waste by Liquid–Liquid Extraction Using Tri-n-octylamine Solvent after Selective Acid Leaching

The effectiveness of ion exchange resins in separating uranium and thorium from rare earth elements in acidic aqueous sulfate media. Part 1. Anionic and cationic resins

Solvent extraction of thorium(IV) and rare earth elements with novel polyaramide extractant containing preorganized chelating groups

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