Method for separating uranium and thorium and reagent used for separation

Abstract

The invention discloses a method for separating uranium and thorium and an extraction agent used for separation. According to the method, uranium and thorium nitrate mixed aqueous solution is placed in imidazolyl ionic liquid diluent in which the reagent is dissolved or n-amyl alcohol diluent in which the reagent is dissolved, thorium is extracted, and uranium stays in an aqueous phase. The extraction agent used for separation is1-methylimidazole showed in a first formula or 2-methylimidazole showed in a second formula. The method and the reagent have the advantages that the extraction agent is cheap and can be obtained easily, an extraction system is simple, extraction efficiency is high, the number of used extraction agents is small, and specificity is strong.

Description

technical field [0001] The invention relates to a method for separating radioactive elements, more precisely, the invention relates to a method for extracting and separating uranium and thorium and the extractant used. Background technique [0002] Both uranium and thorium are important raw materials in the nuclear industry. At the same time, their radioactivity pollutes the environment and threatens human health. Therefore, the separation and determination of uranium and thorium are very important no matter in the application of nuclear fuel or in environmental treatment. The methods widely studied and applied to the separation and determination of uranium and thorium include precipitation method (including co-precipitation, etc.), solvent extraction, ion exchange, foam flotation, membrane dialysis, adsorption separation, extraction chromatography separation (including solid phase extraction chromatography SPE ), electrodeposition, etc. The more traditional of these meth...

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Problems solved by technology

[0004] (2) Sulfur-containing extractants, such as: HBMPPT-DOS0, HBMPPT-PS0, HBMPPT-TBP, HBMPPT-TOPO series, the separation coefficient of extracting uranium and thorium is relatively high Among them, HBMPPT-PS0 has the best extraction effect in toluene. This series of extraction agents has good thermal stability and strong extraction capacity, but it is necessary to find an ideal co-extraction agent, and the recovery of the solvent is relatively difficult.

[0005] (3) Supramolecular compound extractants such as crown ethers and calixarenes, such as poly[dibenzo-18-ring-6] reported by Sandip R. Sabale in 2010 as a stationary phase, and L-arginine aqueous solution as a mobile The phase is used to extract and chromatographically separate uranium and thorium, which has a good effect; then in 2012, R. B. Kadam et al. reported that poly[dibenzo-18-cyclo-6] was used as the stationary phase and glycine aqueous solution was used as the mobile phase. Extraction chromatography separates uranium and thorium. This series of methods is simple and fast, with high selectivity and good reproducibility, but the raw materials are relatively expensive and the synthesis of the extractant is complicated.

[0006] (4) Other synthetic organic extractants, such as DMDOHEMA and TODGA reported by K. Van Hecke et al. in 2003, Cyanex-923 reported by SNEHAL M. et al. in 2009, TBEP reported by Sujoy Biswas et al. in 2010 and Fang Kong in 2013 , TiAP-KO reported by Jia-li Liao et al. is superior to traditional TBP in terms of extraction performance, and the selectivity is also good, but the preparation process of the extractant is relatively complicated, and its practical application is also subject to various limitations (Journal of Radioanalytical and Nuclear Chemistry , Vol. 261, No. 2 (2004) 269-275; J. Serb. Chem. Soc. 75 (11) 1549–1557 (2010), JSCS–4075; J Radioanal Nucl Chem (2010) 283:665–668 ; J Radioanal Nucl Chem, DOI 10.1007 / s10967-013-2482-2)

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