The mixture of(2NaBH4+ MnCl2) was ball milled in a magneto-mill. No gas release was detected. The XRD patterns of the ball milled mixture exhibit only the Bragg diffraction peaks of the Na Cl-type salt which on the ba...The mixture of(2NaBH4+ MnCl2) was ball milled in a magneto-mill. No gas release was detected. The XRD patterns of the ball milled mixture exhibit only the Bragg diffraction peaks of the Na Cl-type salt which on the basis of the present X-ray diffraction results and the literature is likely to be a solid solution Na(Cl)x(BH4)(1-x), possessing a cubic Na Cl-type crystalline structure. No presence of any crystalline hydride was detected by powder X-ray diffraction which clearly shows that NaBH4in the initial mixture must have reacted with MnCl2forming a Na Cl-type by-product and another hydride that does not exhibit X-ray Bragg diffraction peaks. Mass spectrometry(MS) of gas released from the ball milled mixture during combined MS/thermogravimetric analysis(TGA)/differential scanning calorimetry(DSC) experiments, confirms mainly hydrogen(H2) with a small quantity of diborane gas, B2H6. The Fourier transform infra-red(FT-IR) spectrum of the ball milled(2NaBH4+ MnCl2) is quite similar to the FT-IR spectrum of crystalline manganese borohydride, c-Mn(BH4)2, synthesized by ball milling, which strongly suggests that the amorphous hydride mechano-chemically synthesized during ball milling could be an amorphous manganese borohydride. Remarkably, the process of solvent filtration and extraction at 42 °C, resulted in the transformation of mechano-chemically synthesized amorphous manganese borohydride to a nanostructured,crystalline, c-Mn(BH4)2hydride.展开更多
The extraction behavior of uranium(VI) from thiocyanate medium with dibenzo-18-crown-6 (DBC) in nitrobenzene and the effects of alkali canons on the extraction were investigated. The results showed that the uranium (V...The extraction behavior of uranium(VI) from thiocyanate medium with dibenzo-18-crown-6 (DBC) in nitrobenzene and the effects of alkali canons on the extraction were investigated. The results showed that the uranium (VI) can be effectively extracted in the presence of potassium canon, uranium (VI) is extracted as complex anionic species UO2(SCN)2, and the stoichiometry of the extracted complex is KUO2(SCN)32DBC(o)’展开更多
The laser-induced optical fiber fluorimetry has been used for the first time to analyse the concentration of uranium(VI) in the kinetic studies on the extraction of uranium(VI) between 0.5 mol/L H_3PO_4 solution and H...The laser-induced optical fiber fluorimetry has been used for the first time to analyse the concentration of uranium(VI) in the kinetic studies on the extraction of uranium(VI) between 0.5 mol/L H_3PO_4 solution and HDEHP-cyclohexane system with Lewis cell. The effects of stirring speed, temper- ature and concentration of uranium(VI) and HDEHP on the rate of extraction were examined. These data show that the extraction rate of uranium(VI) in this system is controlled by the chemical reaction process at the interface. The rate equations and the rate constants of the forward and reverse ex- tractions were obtained. The mechanism of the extraction has been discussed.展开更多
The solvent extraction of uranium(VI) and europium(III) from nitric acid solution was studied with pi- colinamide dissolved in ethylene dichloride. The distribution ratios of U(VI) and Eu(III) as a function of aqueous...The solvent extraction of uranium(VI) and europium(III) from nitric acid solution was studied with pi- colinamide dissolved in ethylene dichloride. The distribution ratios of U(VI) and Eu(III) as a function of aqueous HNO3 concentration , extractant concentration in organic phase and temperature as well as the salting-out agent con- centration have been measured. The experiment results show that picolinamide has higher extractability for U(VI) than for Eu(III). The composition of extracted species, equilibrium constants and enthalpies of extraction reaction have also been presented.展开更多
A new kind of diamide N,N,N’,N’-tetrahexylsuccinylamide（THSA） was synthesized, characterized and used for the extraction of HNO3, U（VI） and TI（IV） in a diluent composed of 0.5 volume fraction 1,2,4-trimethy be...A new kind of diamide N,N,N’,N’-tetrahexylsuccinylamide（THSA） was synthesized, characterized and used for the extraction of HNO3, U（VI） and TI（IV） in a diluent composed of 0.5 volume fraction 1,2,4-trimethy benzene（TMB） and 0.5 volume fraction kerosene（OK）. Extraction distribution coefficients of U（VI） and TI（IV） as functions of aque- ous nitric acid concentration, extractant concentration, temperature and salting-out agent （LiNO3 ） have been studied, and it is found that THSA as an extractant is superior to TBP for extraction of U（VI） and TI（IV）. Back extraction was also studied. At low acidity, the main adduct of THSA and HNO3 is HNO3.THSA. THSA.（HNO3）2 and THSA.（HNO3）3 are also found at high acidity. The compositions of extracted species, apparent equilibrium constants and enthalpies of extraction reactions have also been calculated.展开更多
The extraction of uranium ((Ⅵ) from nitric acid solution with N-octanoyl-2-methylpiperidine (OMPPD)in eight diluents and the dependence of distribution ratio on temperature and concentrations of both aqueous nitricac...The extraction of uranium ((Ⅵ) from nitric acid solution with N-octanoyl-2-methylpiperidine (OMPPD)in eight diluents and the dependence of distribution ratio on temperature and concentrations of both aqueous nitricacid and OMPPD were investigated. The interaction among OMPPD, the extracted species and diluent has been dis-cussed. The experiments show that the extraction ability of OMPPD decreases gradually for eight diluents in the fol-lowing order: benzene, toluene, n-octane, sulfonated kerosene, cyclohexane, carbon tetrachloride, 1,2-dichloroetheneand chloroform. It cannot be interpreted only on the basis of polarity of diluents.展开更多
The extraction of uranium (Ⅵ) by bis(hexylsulfinyl)ethane(BHxSE) in nitric acid aqueous solution hasbeen investigated. The extracted species appeared to be UO2(NO3)2@2BHxSE. Influences of nitric acid concentration,Na...The extraction of uranium (Ⅵ) by bis(hexylsulfinyl)ethane(BHxSE) in nitric acid aqueous solution hasbeen investigated. The extracted species appeared to be UO2(NO3)2@2BHxSE. Influences of nitric acid concentration,NaNO3 concentration, Na2C2O4 concentration and temperature on the extraction equilibrium were investigated andthe thermodynamic functions of the extraction reaction were obtained.展开更多
Extraction behavior of N,N'-didecanoylpiperazine(DDPEZ)for U(VI) in a series of solvents from aqueous nitric acid media was investigated for the first time.The dependence of distribution ratios on the concentratio...Extraction behavior of N,N'-didecanoylpiperazine(DDPEZ)for U(VI) in a series of solvents from aqueous nitric acid media was investigated for the first time.The dependence of distribution ratios on the concentration of aqueous nitric acid,extractant and temperature has been discussed.The increasing sequence of extractive ability of DDPEZ is given:chloroform,carbon tetrachloride,dimethylbenzene,toluene,benzene.展开更多
The extraction behaviors of uranium （VI） from nitric acid by N-decanoylpyrrolidine （DPOD） in toluene has been studied at varying concentrations of nitric acid, extractant, salting out agent LiNO3 and at different ...The extraction behaviors of uranium （VI） from nitric acid by N-decanoylpyrrolidine （DPOD） in toluene has been studied at varying concentrations of nitric acid, extractant, salting out agent LiNO3 and at different temperatures. The mechanism of extraction is discussed in the light of the results obtained.展开更多
Extraction of uranium with N-octanoylpyrrolidine (OPOD) in sulfonated kerosene from aqueous nitric acid media has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nit...Extraction of uranium with N-octanoylpyrrolidine (OPOD) in sulfonated kerosene from aqueous nitric acid media has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nitric acid, extractant, salting-out agent and the temperature was investigated. The constitution of extracted complex was established, and the related thermodynamic functions were calculated.展开更多
Extraction behavior of thorium(Ⅳ) and uranium(Ⅵ) from nitric acid(HNO_3) was studied using N,N,N',N'-tetraoctyldiglycolamide(TODGA) as extractant in different ionic liquids, and isooctane as comparison.Slope...Extraction behavior of thorium(Ⅳ) and uranium(Ⅵ) from nitric acid(HNO_3) was studied using N,N,N',N'-tetraoctyldiglycolamide(TODGA) as extractant in different ionic liquids, and isooctane as comparison.Slope analyses with varying HNO_3 concentrations and diluents revealed the extraction mechanism. With increasing length of alkyl chain and HNO_3 concentration, the extraction mechanism of TODGA/IL system changed from cation exchange to neutral complex and/or anion exchange,and the molar ratio between TODGA and metal ions varied gradually from 2:1 to 1:1 for Th(Ⅳ) and 3:1 to 1:1 for U(Ⅵ). The kinetics and thermodynamic studies of Th(Ⅳ)and U(Ⅵ) by the best TODGA/[C_2mim][NTf_2] system showed that the extraction equilibrium was reached within 2 h and extraction reactions were endothermic. Compared to TODGA/isooctane system, TODGA/[C_2mim][NTf_2]system presented higher radiation stability under c-irradiation. Therefore, it would have a promising application in spent fuel reprocessing.展开更多
The mechanism of extraction uranium(Ⅵ) with di(2-ethylhexyl) sulfoxide (DEHSO)from aqueous nitric acid media has been studied. The influence of the concentrations of nitricacid, cxtractant, salting-out agent, tempera...The mechanism of extraction uranium(Ⅵ) with di(2-ethylhexyl) sulfoxide (DEHSO)from aqueous nitric acid media has been studied. The influence of the concentrations of nitricacid, cxtractant, salting-out agent, temperature and complex anions (C2O24-) on the distribution ratio was studied.展开更多
The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum syner...The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum synergistic extraction effect occurs where the molar ratio of PSO to TBP is one to two. The composition of the complex of synergistic extraction is UO2(NO3)2-TBP.PSO. The formation constant of the complex KTp=57.44.展开更多
Porphyrinoid metal-organic frameworks(MOFs)with dual effective uranium uptake sites were synthesized through combined insitu and post-synthetic method.The MOF10@5 demonstrates the uptake amount of uranium reaches 1476...Porphyrinoid metal-organic frameworks(MOFs)with dual effective uranium uptake sites were synthesized through combined insitu and post-synthetic method.The MOF10@5 demonstrates the uptake amount of uranium reaches 1476 mg/g under visiblelight irradiation.The PN-MOF10@5 with dual uranyl uptake sites yields the amount of extracting uranyl of 1590 mg/g under visible-light irradiation.The density functional theory(DFT)calculations reveal strong interaction between uranyl and dual uranyl effective active sites.These MOFs demonstrate a powerful synthesis strategy for uranium extraction materials with dual effective active sites.展开更多
基金supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery grant to Prof. R.A. Varin
文摘The mixture of(2NaBH4+ MnCl2) was ball milled in a magneto-mill. No gas release was detected. The XRD patterns of the ball milled mixture exhibit only the Bragg diffraction peaks of the Na Cl-type salt which on the basis of the present X-ray diffraction results and the literature is likely to be a solid solution Na(Cl)x(BH4)(1-x), possessing a cubic Na Cl-type crystalline structure. No presence of any crystalline hydride was detected by powder X-ray diffraction which clearly shows that NaBH4in the initial mixture must have reacted with MnCl2forming a Na Cl-type by-product and another hydride that does not exhibit X-ray Bragg diffraction peaks. Mass spectrometry(MS) of gas released from the ball milled mixture during combined MS/thermogravimetric analysis(TGA)/differential scanning calorimetry(DSC) experiments, confirms mainly hydrogen(H2) with a small quantity of diborane gas, B2H6. The Fourier transform infra-red(FT-IR) spectrum of the ball milled(2NaBH4+ MnCl2) is quite similar to the FT-IR spectrum of crystalline manganese borohydride, c-Mn(BH4)2, synthesized by ball milling, which strongly suggests that the amorphous hydride mechano-chemically synthesized during ball milling could be an amorphous manganese borohydride. Remarkably, the process of solvent filtration and extraction at 42 °C, resulted in the transformation of mechano-chemically synthesized amorphous manganese borohydride to a nanostructured,crystalline, c-Mn(BH4)2hydride.
基金Nuclear Industrial Science Foundation of China (J 95 GY 403)
文摘The extraction behavior of uranium(VI) from thiocyanate medium with dibenzo-18-crown-6 (DBC) in nitrobenzene and the effects of alkali canons on the extraction were investigated. The results showed that the uranium (VI) can be effectively extracted in the presence of potassium canon, uranium (VI) is extracted as complex anionic species UO2(SCN)2, and the stoichiometry of the extracted complex is KUO2(SCN)32DBC(o)’
文摘The laser-induced optical fiber fluorimetry has been used for the first time to analyse the concentration of uranium(VI) in the kinetic studies on the extraction of uranium(VI) between 0.5 mol/L H_3PO_4 solution and HDEHP-cyclohexane system with Lewis cell. The effects of stirring speed, temper- ature and concentration of uranium(VI) and HDEHP on the rate of extraction were examined. These data show that the extraction rate of uranium(VI) in this system is controlled by the chemical reaction process at the interface. The rate equations and the rate constants of the forward and reverse ex- tractions were obtained. The mechanism of the extraction has been discussed.
文摘The solvent extraction of uranium(VI) and europium(III) from nitric acid solution was studied with pi- colinamide dissolved in ethylene dichloride. The distribution ratios of U(VI) and Eu(III) as a function of aqueous HNO3 concentration , extractant concentration in organic phase and temperature as well as the salting-out agent con- centration have been measured. The experiment results show that picolinamide has higher extractability for U(VI) than for Eu(III). The composition of extracted species, equilibrium constants and enthalpies of extraction reaction have also been presented.
文摘A new kind of diamide N,N,N’,N’-tetrahexylsuccinylamide（THSA） was synthesized, characterized and used for the extraction of HNO3, U（VI） and TI（IV） in a diluent composed of 0.5 volume fraction 1,2,4-trimethy benzene（TMB） and 0.5 volume fraction kerosene（OK）. Extraction distribution coefficients of U（VI） and TI（IV） as functions of aque- ous nitric acid concentration, extractant concentration, temperature and salting-out agent （LiNO3 ） have been studied, and it is found that THSA as an extractant is superior to TBP for extraction of U（VI） and TI（IV）. Back extraction was also studied. At low acidity, the main adduct of THSA and HNO3 is HNO3.THSA. THSA.（HNO3）2 and THSA.（HNO3）3 are also found at high acidity. The compositions of extracted species, apparent equilibrium constants and enthalpies of extraction reactions have also been calculated.
文摘The extraction of uranium ((Ⅵ) from nitric acid solution with N-octanoyl-2-methylpiperidine (OMPPD)in eight diluents and the dependence of distribution ratio on temperature and concentrations of both aqueous nitricacid and OMPPD were investigated. The interaction among OMPPD, the extracted species and diluent has been dis-cussed. The experiments show that the extraction ability of OMPPD decreases gradually for eight diluents in the fol-lowing order: benzene, toluene, n-octane, sulfonated kerosene, cyclohexane, carbon tetrachloride, 1,2-dichloroetheneand chloroform. It cannot be interpreted only on the basis of polarity of diluents.
基金the National Natural Sciences Foundation of China (20171029)the National Sciences Foundation of Shandong Province(Y2002B12).
文摘The extraction of uranium (Ⅵ) by bis(hexylsulfinyl)ethane(BHxSE) in nitric acid aqueous solution hasbeen investigated. The extracted species appeared to be UO2(NO3)2@2BHxSE. Influences of nitric acid concentration,NaNO3 concentration, Na2C2O4 concentration and temperature on the extraction equilibrium were investigated andthe thermodynamic functions of the extraction reaction were obtained.
文摘Extraction behavior of N,N'-didecanoylpiperazine(DDPEZ)for U(VI) in a series of solvents from aqueous nitric acid media was investigated for the first time.The dependence of distribution ratios on the concentration of aqueous nitric acid,extractant and temperature has been discussed.The increasing sequence of extractive ability of DDPEZ is given:chloroform,carbon tetrachloride,dimethylbenzene,toluene,benzene.
文摘The extraction behaviors of uranium （VI） from nitric acid by N-decanoylpyrrolidine （DPOD） in toluene has been studied at varying concentrations of nitric acid, extractant, salting out agent LiNO3 and at different temperatures. The mechanism of extraction is discussed in the light of the results obtained.
文摘Extraction of uranium with N-octanoylpyrrolidine (OPOD) in sulfonated kerosene from aqueous nitric acid media has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nitric acid, extractant, salting-out agent and the temperature was investigated. The constitution of extracted complex was established, and the related thermodynamic functions were calculated.
基金financially supported by the National Natural Science Foundation of China(No.11475112)the Ph.D. Programs Foundation of Ministry of Education of China(No.20130073120051)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning
文摘Extraction behavior of thorium(Ⅳ) and uranium(Ⅵ) from nitric acid(HNO_3) was studied using N,N,N',N'-tetraoctyldiglycolamide(TODGA) as extractant in different ionic liquids, and isooctane as comparison.Slope analyses with varying HNO_3 concentrations and diluents revealed the extraction mechanism. With increasing length of alkyl chain and HNO_3 concentration, the extraction mechanism of TODGA/IL system changed from cation exchange to neutral complex and/or anion exchange,and the molar ratio between TODGA and metal ions varied gradually from 2:1 to 1:1 for Th(Ⅳ) and 3:1 to 1:1 for U(Ⅵ). The kinetics and thermodynamic studies of Th(Ⅳ)and U(Ⅵ) by the best TODGA/[C_2mim][NTf_2] system showed that the extraction equilibrium was reached within 2 h and extraction reactions were endothermic. Compared to TODGA/isooctane system, TODGA/[C_2mim][NTf_2]system presented higher radiation stability under c-irradiation. Therefore, it would have a promising application in spent fuel reprocessing.
文摘The mechanism of extraction uranium(Ⅵ) with di(2-ethylhexyl) sulfoxide (DEHSO)from aqueous nitric acid media has been studied. The influence of the concentrations of nitricacid, cxtractant, salting-out agent, temperature and complex anions (C2O24-) on the distribution ratio was studied.
基金Supported by the National Natural Science Foundation of China (20171029)
文摘The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum synergistic extraction effect occurs where the molar ratio of PSO to TBP is one to two. The composition of the complex of synergistic extraction is UO2(NO3)2-TBP.PSO. The formation constant of the complex KTp=57.44.
基金supported by the National Natural Science Foundation of China(No.22301108)the Project Startup Foundation for Distinguished Scholars of Jiangsu University(No.4111310026).
文摘Porphyrinoid metal-organic frameworks(MOFs)with dual effective uranium uptake sites were synthesized through combined insitu and post-synthetic method.The MOF10@5 demonstrates the uptake amount of uranium reaches 1476 mg/g under visiblelight irradiation.The PN-MOF10@5 with dual uranyl uptake sites yields the amount of extracting uranyl of 1590 mg/g under visible-light irradiation.The density functional theory(DFT)calculations reveal strong interaction between uranyl and dual uranyl effective active sites.These MOFs demonstrate a powerful synthesis strategy for uranium extraction materials with dual effective active sites.
