Solvent extraction of U(Ⅵ) by N,N-dimethyl-N',N'-dioctylsuccinylamide and N,N-dimethyl-N',N'-didecylsuccinylamide in cyclohexane

The extraction of uranyl nitrate by novel extractants of N,N-dimethyl-N',N'-dioctylsuccinylamide(DMDOSA)and N,N-dimethyl-N',N'-didecylsuccinylamide(DMDDSA) from aqueous nitric/nitrate solutions was investigated.It was found both the concentration of HNO_3 and extractants had an effect on the U(Ⅵ) extraction distribution.The extraction mechanism was established,and stoichiometry of the main extracted species was confirmed to be UO_2(NO_3)_2·2DMDOSA and UO_2(NO_3)_2·2DMDDSA,respectively.Both of the extraction reactions are exothermic.FTIR spectral study of the U(Ⅵ) extracted species was also made.     

Study on Liquid-Liquid Extraction of Lithium by Benzo-15-Crown-5/Ionic Liquid System

正By using high isotope effect extracting agent benzo-15-crown-5(B15C5,for short)and green and stable solvent ionic liquid[C_4MIm]NTf_2(Fig.1),liquid-liquid extraction system B15C5-[C_4MIm]NTf_2/LiA-H_2O(anion A was NTf_2~-,OTf~-and Cl~-)was established to separate lithium isotopes efficiently.Based on lots of experimental data,the separation system was proved to     

γ-ray induced radiolysis of [C_2mim][NTf_2] and its effects on Dy~(3+) extraction

The water-soluble radiolytic products of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ionic liquid([C2mim][NTf2]) under γ-radiation, such as CF3 SOOH, CF3SO2NH2, HF, and H2SO3, were identified by using1 H NMR,19 F NMR, and ion chromatography. The extraction behavior of Dy3+using irradiated [C2mim][NTf2] in combination with 2,6-di(5,6-diisobutyl-1,2,4-triazin-3-yl)pyridine(isobutyl-BTP)was studied and the abnormal increase of Dy3+partitioning after irradiation is mainly attributed to the precipitation formed between Dy3+and radiolytic products of [C2mim][NTf2](F–and SO2–3). Washing irradiated[C2mim][NTf2] with water provides a simple method for ionic liquid recycling.     

Synergistic extraction of U（VI） and Th（IV） from nitric acid media with HBMPPT and TBP in toluene

The sysnergistic extraction of U(VI)and Th(IV) from nitric acid solution by HBMPPT(4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione) and TBP( tributylphosphate)in toluene was studied.The extraction ability of HBMPPT for U(VI) and Th(IV) was not so high.but when a little TBP was added in,the ability to extract U(VI) and Th(IV) was improved.The extracted complexes may be presented as UO2NO3.BMPPT.TBP and UO2(BMPPT)2.TBP for U(VI).and Th(NO3)3.BMPPT.TBP and Th(NO3)2(BMPPT)2.TBP for Th(IV),respectively,in the synergistic extraction system.The synergistic effect of HBMPPT and TBP makes the separation cofeeicient of U(VI)/Th (IV) or U(VI)/Eu(Ⅲ) reach a high value.     

Extraction chromatography–electrodeposition(EC–ED) process to recover palladium from high-level liquid waste

The extraction chromatography–electrodeposition(EC–ED) process was proposed for the quantitative recovery of palladium from high-level liquid waste(HLLW) in this study. The process coupled the extraction chromatography method to obtain the decontamination of Pd(II) from HLLW with the electrochemical method to recover metallic palladium from the concentrated solution.Separation of Pd(II) from a nitric acid medium by extraction chromatography using iso Bu-BTP/SiO_2-P adsorbent and the electrochemical behavior of Pd(II) in nitric acid solution in the presence of thiourea(TU) were investigated.iso Bu-BTP/SiO_2-P exhibited a high selectivity for Pd(II)over other fission products(FPs), and Pd(II) could be desorbed by TU from loaded BTP/SiO_2-P. The adsorbent performed good stability against HNO_3 because the adsorption performance kept Pd(II) after extended contact with HNO_3 solution. The column experiment achieved the separation of Pd(II) from simulated HLLW successfully.The electrochemical behavior of Pd(II) in palladium desorption solution containing TU and nitric acid was investigated at a platinum electrode by cyclic voltammetry. A weak reduction wave at-0.4 V was due to the reduction in Pd(II) to Pd(0), and the deposition process wasirreversible. In electrowinning experiments, a maximum of92% palladium could be obtained.     

Extraction of U,Pu,Am,Eu and Sr With TODGA-DHOA/OK

The extraction of U(Ⅵ), Pu(Ⅳ), Am(Ⅲ) Eu(Ⅲ) and Sr(Ⅱ) with N,N,N',N'-tetraoctyl-3-oxapentane diamide (TODGA) and N, N-dihexyl-octanamide (DHOA)/kerosene (OK) as extractants from nitric acid     

SEPARATION AND PURIFICATION OF ^234Th FROM AGED URANIUM SALT

This paper summarizes the results of separation and purification of ^234Th from aged uranium salt with two processes(see flowsheet A or B).The flowsheet.A:TBP extraction,anion exchange and TTA extraction;the flowsheetB:Cation and anion exchange,TTA extraction.The total recovery efficiency of ^234Th is about 90%.The γ-spectrum of the end-product contains only two typic peaks of ^234Th(63and 92keV).Pure ^234Th is prepared.     

Efficient extraction of U(VI) ions from solutions

The rapid development of advanced techniques for selective and efficient U(Ⅵ) extraction from aqueous solutions is essential for addressing U(Ⅵ) environmental pollution and energy issues. Here, we share recent progress in U(Ⅵ) extraction from aqueous solutions, especially the most frequently applied techniques such as adsorption, catalysis(photocatalysis, piezocatalysis, and electrocatalysis), chemical deposition, and reduction by zero-valent metal particles. We attempt to elucidate the strategi...     

The n-Octylododecylsulfoxide(ODSO)-carbon tetrachloride extracting uranium(Ⅵ）

The liquid-liquid extraction behavior of uranium(Ⅵ） from nitric acid aqueous solution with n-octyldodecylsulfoxide(ODSO) has been studied over a wide range of conditions.The extracted species appear to be UO2(NO3)2.2O DSO.It was found that the extraction was increased with increasing sodium nitrate concentration. Extracting also increases with increasing extractant concentration.The influence of temperature and nitric acid concentration on extraction equilibrium was also investigated and gthe enthalpy of the extraction reaction was obtained.     

Extraction of lanthanide ions with N,N,N′,N′-tetrabutyl-3-oxadiglycolamide from nitric acid media

Extractability and extraction mechanism of lanthanide ions were investigated by using a new extractant,N,Nn,N′,N′-tetrabutyl-3-oxa-diglycolamide(TBDGA),in toluene from nitric acid media.The effects of HNO_3 and TBDGA concentrations,and temperature,on extraction of lanthanide ions were studied.Stoichiometrics of the main extracted species were HNO_3·TBDGA and M(NO_3)_3-3TBDGA(M = Er,Dy,Tb,Gd,La,Ce,Nd,Sm and Eu).The extracted species for metal ions were established to be ionic complex.In this complex,nitrate anion was not coordinated to the central ion.The extraction pattern increased gradually across the lanthanide ions series,showing enhanced affinity of TBDGA toward heavy lanthanide ions.Thermodynamic parameters were investigated for the exothermic extraction reaction.     

Solvent extraction of uranium（VI） and thorium（IV） in nitric acid solution by N,N,N‘,N’—tetrabutyladipicamide

N,N,N‘N‘-tetrabutyladipicamide(TBAA) has been synthesized,and applied to the extraction of U(VI) and Th(IV) from nitric acid solutions in a diluent composed of 0.50 volume fraction 1,2,4-trimethyl benzene (TMA) and 0.50 volume fraction kerosene(OK),The effects of the aueous nitric acid concentration,extractant concentration,slating-out agent (LiNO3) and temperature on extraction ability of TBAA for U(VI) and Th(IV) have been studied.Back Extraction of U(VI) and Th (IV) from organic phases were performed by dilute nitric acid.The compositions of extracted complexes,equilibrium constants and enthalpies of extraction reactions have also been estimated.The IR spectra of extraction of U(VI) and Th(IV) have been studied.     

Process Study of Extract Separation of An(Ⅲ) and Ln(Ⅲ)

<正>For the purpose of achieving the real norrcradionuclides of high-level liquid waste in the XX pre-research project,it is necessary to separate Am from high-level liquid waste.According to the preliminary research,TODGA+TBP process has been verified to meet the conditions of this project through cascade experiment,where technological parameters have been further opti-mized.The second step is to realize the separation of An(Ⅲ) and Ln(Ⅲ).Based on the research on the stability of back-extractant PTD and single-stage separation performance,the preliminary work has identified technological parameters of bench experiment.     

Radiochemistry and Nuclear Chemistry Extraction of U, Pu, Am, Eu and Sr With TODGA-DHOA/OK

The extraction of U（Ⅵ）, Pu（Ⅳ）, Am（Ⅲ） Eu（Ⅲ） and Sr（ Ⅱ ） with N,N,N＇,N＇-tetraoctyl-3-oxapentane diamide （TODGA） and N, N-dihexyl-octanamide （DHOA）/kerosene （OK） as extractants from nitric acid solutions has been studied. The results show that the value of D（M） （there, M are U, Pu, Am and Eu） increase with the increasing HNO3 concentration, while the value of D（Sr） reaches the maximum at 3 mol/L HNO3.     

Extraction of U（VI） and Th（IV） with a novel extractant N,N‘—tetrahexylmalonamide （THMA） in toluene

The dependence of THMA extraction behaviour for U(VI) and Th(IV) on nitric acid concentration,THMA concentratioin and molecular structure of extracted complex has been studied.For nitric acid solutions of 3.0 mol/L a coordinative mechanism may possibly dominate in the extraction of metal catioins,The complex composition of UO2(NO3)2(THMA)2,Th(NO3)4(THMA)2 and Th(NO3)4(THMA03 are proved.     

Radiochemical Analysis Auto-system of ~(90)Sr in Liquid Effluent from Nuclear Facility

<正>The analysis of~(90) Sr is an important content in liquid effluent from nuclear facilities and environmental radioactivity monitoring.The traditional analytical methods include fuming nitric acid method,ion exchange,solid-phase extraction method,etc.These analysis methods all relyon manual analysis.In order to further reduce the labor intensity and workload of analysts,an automatic analysis system of 90 Sr in environmental water was developed based on the solid phase extraction technology.     

γ-Ray radiolysis of acetohydroxamic acid in HNO_3 and its radiolytic product

Acetohydroxamic acid(AHA) is a novel saltfree reagent used for the separation of Pu and Np from U in the advanced Purex process. This paper reports the c-ray damage of AHA in HNO_3 and its radiolytic product. For 0.2 mol L~(-1) AHA in 0.2–2.0 mol L~(-1) HNO_3 irradiated at a dose of 5–25 kGy, the radiolytic rate of AHA is6.63–77.5%, and it increases with the HNO_3 concentration and absorbed dose. The main radiolytic gases are N_2O and H_2, with volume fractions of(0.500–16.2) 9 10~(-2) and(1.30–11.8) 9 10~(-3), respectively, and they increase with the absorbed dose; the H_2 volume fraction decreases with increasing HNO_3 concentration. The main liquid radiolytic products are CH_3 COOH and HNO_2, and their concentrations are(3.40–19.7) 9 10~(-2) and(0.200–4.80) 9 10~(-3)-mol L~(-1), respectively, which increase with the HNO_3 concentration. Since a significant concentration of HNO_2 is present in the irradiated AHA-HNO_3 solution, a holding reductant must be used to destroy HNO_2 and stabilize Pu(Ⅲ) and Np(Ⅴ) when AHA is applied for the separation of Pu and Np from U.     

Identification of radiolytic products of [C_4mim][PF_6] under γ-irradiation

The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate([C4mim][PF6]) were identified by analysing water-washed samples of γ-irradiated ionic liquids. HF and difluorophosphinic acid were confirmed as the main radiolytic products of [C4mim][PF6], and their radiation chemical yields were quantified by19 F NMR(G(F-) = 0.14 μmol/J, G(HOP(O)F2) = 0.053 μmol/J). Compared to [C4mim][NTf2], [C4mim][PF6] shows better radiation stability.     

DBC solent extraction of U(Ⅵ） from thiocyanate medium

The extraction behavior of uranium(Ⅵ） from thiocyanate medium with dibenzo-18-crown-6(DBC) in nitrobenzene and the effects of alkali cations on the extraction were investigated,The results showed that the uranium (Ⅵ） can be effectively extracted in the presence of potassium cation ,uranium (Ⅵ） is extracted as complex anionic species UO2(SCN)3^- ,and the stoichiometry of the extracted complex is KUO2(SCN)3 2DBC(o).     

The Separation and Measurement of Np(Ⅴ,Ⅵ) and Its Daughter ~(237)Pa

By means of liquid scintillation measurement of the Np sample solution which reaches 237Np-233Pa equilibrium with its daughter Pa, the detection efficiency of low energy y spectrum at 28.54, 86.59 and 311.98 keV are obtained. Using these data, the separation of different valence of Np from its daughter Pa is studied. The initial valence of Np is Np(Ⅴ) in solution. In order to compare the separation results, H2O2 is used to prepare Np( Ⅴ). Np(Ⅵ) is prepared by K2Cr2O7 and concentrated HNO3, respectively. TTA and/or TOPO and the back-extraction of them are used to separate Np and Pa. It indicates that initial Np( Ⅴ ) can be separated by TTA or TOPO, and the Np     

Reaction Between Mono-methylhydrazine and Tc(Ⅶ) in Nitric Acid Medium

Methyl hydrazine (MMH) is a supporting reagent used in the Purex process in order to eliminate nitrous acid in the system. The reaction between MMH and Tc(Ⅶ) in nitric acid medium was studied by extraction method. The influences of temperature, acidity, the concentrations of MMH and pertechnetate