The extraction and separation of heavy rare earths（REs） using newly synthesized a-aminophosphonic acid extractant 2-ethylhexyl-3-（2-ethylhexylamino）pentan-3-yl phosphonic acid（HEHAPP, HA） in nheptane were invest...The extraction and separation of heavy rare earths（REs） using newly synthesized a-aminophosphonic acid extractant 2-ethylhexyl-3-（2-ethylhexylamino）pentan-3-yl phosphonic acid（HEHAPP, HA） in nheptane were investigated from chloride medium. The extraction stoichiometries of lanthanum, gadolinium, yttrium and lutetium are determined to be REA3 by the slope analysis method. The favorable separation factors of adjacent heavy REs（Ⅲ）,i.e. β（Y/Ho）, β（Er/Y）,β（Tm/Er）,β（Yb/Tm） and β（Lu/Yb）, are determined to be1.87,1.36, 3.21,3.22 and 1.93, respectively, when extracted from a binary system at proper condition. The loading capacities of HA for Ho, Er, Yb and Lu increase in the order Ho 〈 Er 〈 Yb 〈 Lu with the values being 0.201, 0.205, 0.216 and 0.229 mol/L, respectively. So HA would be a potential extractant for the separation of heavy REs（Ⅲ）. Among inorganic acids such as H2 SO4, HNO3 and HCl, HCl is tested to be the most effective stripping agent.展开更多
A novel hydrothermal process was developed to extract zinc from pure zinc ferrite（ZnFe2O4） nanopowder and zinc-containing electric arc furnace（EAF） dust using hexahydrated ferric chloride（FeCl3-6H2O） as a decomp...A novel hydrothermal process was developed to extract zinc from pure zinc ferrite（ZnFe2O4） nanopowder and zinc-containing electric arc furnace（EAF） dust using hexahydrated ferric chloride（FeCl3-6H2O） as a decomposing agent.The effects of solid FeCl3-6H2O to ZnFe2O4 ratio by mass（RF/Z）,hydrothermal reaction temperature,and time on zinc extraction were systematically investigated.In the results,when the hydrothermal reaction is conducted at 150℃ for 2 h with RF/Z of 15：20,the efficiency of zinc extraction from ZnFe2O4 reaches97.2%,and the concentration of ferric ions（Fe^3＋） in the leaching solution is nearly zero,indicating a high selectivity for zinc.In addition,the zinc extraction efficiency from the EAF dust reaches 94.5%in the case of the hydrothermal reaction performed at 200℃ for 10 h with the solid FeCl3-6H2O to EAF dust ratio by mass（RF/EAF dust） of 15：10.Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.展开更多
A process for actinide(Ⅲ)and lanthanum(Ⅲ)extraction separation from high-level liquid waste(HLLW)was proposed,with N,N,N’,N’-tetraoctyl diglycolamide(TODGA)as the extractant,tri-n–butyl phosphate(TBP)as the phase...A process for actinide(Ⅲ)and lanthanum(Ⅲ)extraction separation from high-level liquid waste(HLLW)was proposed,with N,N,N’,N’-tetraoctyl diglycolamide(TODGA)as the extractant,tri-n–butyl phosphate(TBP)as the phase modifier and 2,6-bis[1-(propan-1-ol)-1,2,3-triazol-4-yl]pyridine(PyTri-Diol or PTD)as hydrophilic stripping agent.This‘hot test’was successfully carried out,achieving 99.92%removal of americium-241(^(241)Am)with a separation factor SF(Eu/Am)of 3.8×10^(3)in the actinide(Ⅲ)product solution.The results show that bisamide podand extractants can effectively realize the extraction and separation of actinide(Ⅲ)and lanthanum(Ⅲ)from Chinese commercial HLLW and thus have a bright practical application potential for the treatment of commercial HLLW.展开更多
The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation betwee...The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.展开更多
Rational design of extractant structure to improve the extraction and separation capacity of rare earth elements(REEs)is a long-standing challenge.Herein,a new strategy was proposed to improve the stability of the che...Rational design of extractant structure to improve the extraction and separation capacity of rare earth elements(REEs)is a long-standing challenge.Herein,a new strategy was proposed to improve the stability of the chelating structure formed by malonamide and REEs.The stability of the chelating structure is greatly improved by using a double-ring framework structure which makes the two carbonyl groups of malonamide unable to rotate freely and both of them point to the metal ion position.Three benzyl groups were used to construct the hydrophobicity of the extractant and the organic shell of the extracted species.Tribenzylhexahydro-pyrrolo-pyridine-dione(THPPD)was designed and synthesized.The structure reduces the energy consumed by rotating carbonyl group in the coordination with metal ions and then improves the extraction ability of extractant.The crystal structure was preorganized as expected,with the two carbonyls pointing in a favorable coordination direction to the structural complement of the metal ion.The extraction behaviors of REEs with THPPD in a nitric acid medium were studied.Compared with N,N’-dibenzyl-N,N’-dimethylmalonamide(DBDM-MA)with a chain structure,the extraction capacity of THPPD is 360 times higher than that of DBDM-MA at 5.0 mol/L sodium nitrate.Furthermore,the binding energy and Gibbs free energy were investigated by density functional theory(DFT)in conjunction with the B3LYP.The theoretical results show that THPPD has more effective interaction with Pr(NO_(3))3 than DBDM-MA.The construction of chelating groups conformation is a worthy direction to improve the coordination ability and even selectivity of extractant.展开更多
This paper reviewed various systems such as neutral phosphorus and acid phosphorus, carboxylic acid and amine extractant for solvent extraction chemistry of yttrium, including thermodynamics, kinetics and yttrium extr...This paper reviewed various systems such as neutral phosphorus and acid phosphorus, carboxylic acid and amine extractant for solvent extraction chemistry of yttrium, including thermodynamics, kinetics and yttrium extracting separation process containing the development course and new separation process.展开更多
Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution ...Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution of monomyristyl phosphoric acid (MPA) in chloroform.Mineral acids are used as developers. The effect of concentration of acids and/or salts upon R_f has been investigated.According to the re- sults of R_f values for a given rare earth element in various acids,the order of extraction ability is HCl>HNO_3>H_2SO_4.A tetrad effect is clearly observed.for the R_f value of rare earth elements.The effects of other parameters on the R_f value,such as the quantities of extractant retained by the paper and the temperature are also examined.Based on the determination of the molar ratio of MPA to rare earth elements and the number of H^+ ions released in extraction reaction,a reasonable mechanism is proposed.The mutual separation of heavy rare earth elements will be better than that of the light rare earth group because of the larger separation coefficient of the former.A mixture of Ho-Er-Tm-Lu is successfully separated by the present method.展开更多
Separation technology of rare earth elements （REEs）, as the critical step in the separation process, had long been fraught with technical difficulty. A research project conducted by Baotou Shibo Rare Earth Extracti...Separation technology of rare earth elements （REEs）, as the critical step in the separation process, had long been fraught with technical difficulty. A research project conducted by Baotou Shibo Rare Earth Extraction ＆ Equipment Co. Ltd., Baotou REE Research Institute, and Baotou Steel ＆ REE Group Hi-Tech Co. Ltd （Inner Mongolia）, has successfully solved the problem using a centrifugal extractor and advanced techniques to achieve a key breakthrough.展开更多
An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo wa...An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo was studied. The precursor solution was obtained via evaporation deamination and H202-complex transformation processes. Then it was extracted with a mixture extractant of tri-alkyl phosphine oxide （TRPO） and tributyl phosphate （TBP） to separate Mo and W. The results indicated that the evaporation deamination complex method reduced the acid consumption by more than 90% in comparison with the traditional directly acid regulation complex method. The transformation rates of W and Mo were higher than 95% and the decomposition rate of H202 was less than 15% at a 1.8-1.9 times H202 dosage, 45-50 ℃, initial pH of 1.80-1.90, and transformation volume ratio of 100% for 60 min in the H2O2-complexation transformation process. The minimum extraction rate of W was 2%, the maximum extraction rate of Mo was 82.6% and the highest separation coefficient was 76.7 in a single-stage extraction.展开更多
tert-butanol and ethyl acetate,as fuel additives and oxygenated fuels,can improve fuels quality and reduce exhaust emissions.Therefore,the recovery of these compounds from azeotropic systems is of great significance.I...tert-butanol and ethyl acetate,as fuel additives and oxygenated fuels,can improve fuels quality and reduce exhaust emissions.Therefore,the recovery of these compounds from azeotropic systems is of great significance.Ionic liquids(ILs)are promising green solvents for separating azeotropic systems.In this study,an efficient extraction strategy based on 1-butyl-3-methylimidazolium acetate([Bmim][AC])is proposed.The mechanism by which ILs enable the separation of binary alcohol-ester azeotropes was revealed by evaluating the lowest conformational energy through combining an independent gradient model based on the Hirshfeld partition(IGMH)and frontier molecular orbitals,to preliminarily screen the extractants.The range of extractants was further reduced by a vapor–liquid phase equilibrium(VLE)experiment,and a modeling method for separating the alcohol–ester system and recovering the solvent using[Bmim][AC]and 1-ethyl-3-methyl-3-imidazolium acetate([Emim][AC])is established.Under the optimal operating conditions,the use of[Bmim][AC]can reduce the total annual cost(TAC)per year by 17.78%,and the emissions of CO_(2),SO_(2),and NO can be reduced by 10.86%.In this study,a comprehensive method for screening extractants is proposed,and the simulation process is optimized in combination with the economic and environmental impact.The results have important guiding significance for realizing efficient,energy-saving,and green azeotropic separation systems in industry.展开更多
A new method to extract and separate tetracycline（TC） in a new aqueous tyro-phase system（ATPS） consisting of hydrophilic [Bmim]BF4 and NaH2PO4 was investigated. The effects of the amount of salt, ionic liquid as w...A new method to extract and separate tetracycline（TC） in a new aqueous tyro-phase system（ATPS） consisting of hydrophilic [Bmim]BF4 and NaH2PO4 was investigated. The effects of the amount of salt, ionic liquid as well as tetracycline on extraction efficiency were studied systematically. The results show that ionic liquid-ATPS exhibited the highest extraction efficiency higher than 90%. When the concentration of NaH2PO4 was 33.3%--38.5% （mass fraction）, the amounts of ionic liquid and TC were 1.0--2.0 mL and 1.8 mL, respectively, and ionic liquid could be re-used.展开更多
In view of the problem of ammonia-nitrogen wastewater pollution in rare earths extraction and separation, the novel saponification agent of organic phase, which is magnesium bicarbonate solution, was prepared with the...In view of the problem of ammonia-nitrogen wastewater pollution in rare earths extraction and separation, the novel saponification agent of organic phase, which is magnesium bicarbonate solution, was prepared with the natural rich and cheap dolomite as raw material through carbonation process. The behavior and purification of main impurities ions in the carbonation process as well as the application effect of the novel saponification agent in the extraction and separation was researched. The results showed that the concentration of Fe, A1, Si im- purities ions was.less than 5 ppm in the saponification agent through the development of effective removal technology, respectively. When the novel saponification agent was used in the extraction and separation, magnesium utilization rate was more than 95%, and rare earths extrac- tion rate above 99.5% has achieved. Therefore, the technology could replace ammonia-water to saponify the organic phase in rare earth ex- traction and separation process.展开更多
The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and inso...The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and insoluble fraction(CT-HI)were obtained by n-heptane Soxhlet extraction.The extraction rate of CT-HS reached 92.79%(mass),which indicated that there are few heavy compounds in it.Further,different solvents(methylbenzene,benzene,ethyl acetate,methylbenzene-ethanol)were used to elute CT-HS by chromatographic column to obtain five fractions(saturates,aromatics,heteroatoms,phenolics and resins,named CT-SA,CT-AR,CT-HE,CT-PH,CT-RE,respectively).The yields of CTSA,CT-AR,CT-HE,CT-PH,CT-RE are 42.12%,10.43%,2.19%,9.50%and 6.63%(mass),respectively.Gas chromatography-mass spectrometry analysis of eluting components show that alkanes are the main components in CT,followed by polycyclic aromatics,and the corresponding fractions are CT-SA and CT-AR,respectively.The relative content of aliphatics in CT-SA is 76.93%,and the relative content of aromatics in CT-AR is 75.05%.This separation technology effectively separates and enriches different components in CT,and the activation energy required for the pyrolysis process of a single eluting fraction is lower than that of CT,which is expected to provide an important reference for the separation,analysis and conversion of complex oil products such as coal-oil co-processing products,coal tar and other complex heavy carbon oil products.展开更多
China is a major producer of rhenium, which is widely used in aerospace technologies （as superalloy） and petrochemical industries （as catalyst）. There is a gap between the demand and fact for the enrichment of rhe...China is a major producer of rhenium, which is widely used in aerospace technologies （as superalloy） and petrochemical industries （as catalyst）. There is a gap between the demand and fact for the enrichment of rhenium, due to its rather small content （10-9） in the earth＇s crust. Also, there is no available single occurrence of mineral rhenium. Instead, the rhenium is associated with either molybdenum or copper （of up to 0.2% in content） as a by-product in metallurgical industry. This makes the separation of rhenium from the major mineral metals a challenge. The recent progresses in the separation and enrichment of rhenium were reviewed in this paper, especially, the advances in China. The details of varied separation methods used either in laboratories or factories, such as ion-exchange, solvent extraction, separation utilizing extractive resins, liquid membrane, or novel materials, etc., were elaborated. Comparison of the different methods was disclosed and an outlook on the rhenium chemistry and industry in the future was brought forward.展开更多
A number of epuilibrium data of single stage in the system (Nd-SM)Cl_3-HCl-H_2O-1mol/L HEHEHP-kerosence was determined On the basis of epuilibrium data, two mathematical describing extract epui-librium of Nd and Sm...A number of epuilibrium data of single stage in the system (Nd-SM)Cl_3-HCl-H_2O-1mol/L HEHEHP-kerosence was determined On the basis of epuilibrium data, two mathematical describing extract epui-librium of Nd and Sm were developed.The models cover wide available ranges (the total RE concentration inepuilibrated apueous phase is 0. 07～0. 77 mol/L and the acidity is 0. 11～0. 48 mol/L; the mole fraction ofMd or Sm is 0. 020～0. 998) with small average relative errors(The model of Nd is 6. 11 % and the model ofSm is 3. 07 %, respectively ) With the developed models, the extract behaviors of Nd and sM, such as thedistribution of rare earth concentrations in both phase, the effects of acidity, RE concentration, mole fractionof RE in aqueous phase on the RE concentration in organic phase, were researched The separation circuits be-tween Nd and Sm simulated and performed by the experiments in laboratory. The purities obtained prod-uct of Nd_2O_3O_3 as well as Sm_2O_3 were higher than 99%.Two calculation programs were written in BASIC language. One of them is used for publishing epuilibri-um model and another is used for simulation of fractional solvent extraction. The amulation results obtainedmay serve as a reference for designing solvent extraction process.展开更多
In recent years,with the rapid developme nt of the econo my and society,pollution of valuable metal ions in wastewater has become a major challenge to environmental sustainability.In order to solve the pollution cause...In recent years,with the rapid developme nt of the econo my and society,pollution of valuable metal ions in wastewater has become a major challenge to environmental sustainability.In order to solve the pollution caused by metal ions,researchers have conducted continuous re searches and explored various re mediation methods.Crown ether has attracted great attention because of its ionic radius and cavity size matching well with metal ions,which makes it have the ability to selectively complex metal ions.This unique property enables the directed removal and recovery of metal ions and makes crown ethers increasingly popular in extraction and separation processes.In this paper,the research progress of crown ethers in the extraction and separation of valuable metal ions was reviewed,with emphasis on the principles,extraction systems and the key factors affecting the extraction process.This study can provide some technical support for the application of separation and extraction of valuable metal ions by crown ether.展开更多
Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extractio...Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.展开更多
The radioactivity of uranium in radioactive coal bottom ash（CBA） may be a potential danger to the ambient environment and human health. Concerning the limited research on the distribution and mode of occurrence of u...The radioactivity of uranium in radioactive coal bottom ash（CBA） may be a potential danger to the ambient environment and human health. Concerning the limited research on the distribution and mode of occurrence of uranium in CBA, we herein report our investigations into this topic using a number of techniques including a five-step Tessier sequential extraction, hydrogen fluoride（HF） leaching, Siroquant（Rietveld） quantification, magnetic separation, and electron probe microanalysis（EPMA）. The Tessier sequential extraction showed that the uranium in the residual and Fe–Mn oxide fractions was dominant（59.1%and 34.9%, respectively）. The former was mainly incorporated into aluminosilicates,retained with glass and cristobalite, whereas the latter was especially enriched in the magnetic fraction, of which about 50% was present with magnetite（Fe_3O_4） and the rest in other iron oxides. In addition, the uranium in the magnetic fraction was 2.6 times that in the non-magnetic fraction. The experimental findings in this work may be important for establishing an effective strategy to reduce radioactivity from CBA for the protection of our local environment.展开更多
A multi-objective decision procedure was proposed to select the optimal precase parameters of extractionseporating zirconium and hafnium from sulphuric acid solution with Alamine-336 as an extractant in this pa-per.Ad...A multi-objective decision procedure was proposed to select the optimal precase parameters of extractionseporating zirconium and hafnium from sulphuric acid solution with Alamine-336 as an extractant in this pa-per.Adaptive Random Search(ARS) algorithm was adopted for optimizing calculation. The results obtainedshow that the multi-objective decision method is much better than sangle-objecive decision method.展开更多
[Objectives] Chemical compositions of S. carthamoides root were isolated and identified. [Methods]Solvent extraction,repeated silica gel column chromatography,ODS column chromatography,preparative liquid chromatograph...[Objectives] Chemical compositions of S. carthamoides root were isolated and identified. [Methods]Solvent extraction,repeated silica gel column chromatography,ODS column chromatography,preparative liquid chromatography and recrystallization were used for separation and purification,and chemical structure of compound was identified via its physical-chemical properties and spectral analysis data.[Results] Eight compounds were obtained from methanol extract of S. carthamoides root: 24-ethyl-20-oxhydryl ecdysone( 1),β-ecdysterone( 2),Ajugasterone C( 3),3,4-DHBA( 4),3-methoxy-quercetin( 5),( 7 S,8 S)-syringoylglycerol( 6),( E)-3,7-dimethyl-1-O-[α-L-arabinofuranosyl-( 1→6)-β-D-glucopyranosy1]-oct-2-en-7-ol( 7),Polypodine B( 8). [Conclusions] Compounds 6 and 7 were firstly isolated from the plant.展开更多
基金Project supported by National Basic Research Program of China(973 program,2012CBA01206)the National Natural Science Foundation of China(21521092,51222404)the Strategic Priority Research Program of CAS(XDA02030100)
文摘The extraction and separation of heavy rare earths（REs） using newly synthesized a-aminophosphonic acid extractant 2-ethylhexyl-3-（2-ethylhexylamino）pentan-3-yl phosphonic acid（HEHAPP, HA） in nheptane were investigated from chloride medium. The extraction stoichiometries of lanthanum, gadolinium, yttrium and lutetium are determined to be REA3 by the slope analysis method. The favorable separation factors of adjacent heavy REs（Ⅲ）,i.e. β（Y/Ho）, β（Er/Y）,β（Tm/Er）,β（Yb/Tm） and β（Lu/Yb）, are determined to be1.87,1.36, 3.21,3.22 and 1.93, respectively, when extracted from a binary system at proper condition. The loading capacities of HA for Ho, Er, Yb and Lu increase in the order Ho 〈 Er 〈 Yb 〈 Lu with the values being 0.201, 0.205, 0.216 and 0.229 mol/L, respectively. So HA would be a potential extractant for the separation of heavy REs（Ⅲ）. Among inorganic acids such as H2 SO4, HNO3 and HCl, HCl is tested to be the most effective stripping agent.
基金supported by the National Basic Research Priorities Program of China (Nos. 2014CB643401 and 2013AA032003)the National Natural Science Foundation of China (No.51372019)
文摘A novel hydrothermal process was developed to extract zinc from pure zinc ferrite（ZnFe2O4） nanopowder and zinc-containing electric arc furnace（EAF） dust using hexahydrated ferric chloride（FeCl3-6H2O） as a decomposing agent.The effects of solid FeCl3-6H2O to ZnFe2O4 ratio by mass（RF/Z）,hydrothermal reaction temperature,and time on zinc extraction were systematically investigated.In the results,when the hydrothermal reaction is conducted at 150℃ for 2 h with RF/Z of 15：20,the efficiency of zinc extraction from ZnFe2O4 reaches97.2%,and the concentration of ferric ions（Fe^3＋） in the leaching solution is nearly zero,indicating a high selectivity for zinc.In addition,the zinc extraction efficiency from the EAF dust reaches 94.5%in the case of the hydrothermal reaction performed at 200℃ for 10 h with the solid FeCl3-6H2O to EAF dust ratio by mass（RF/EAF dust） of 15：10.Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.
文摘A process for actinide(Ⅲ)and lanthanum(Ⅲ)extraction separation from high-level liquid waste(HLLW)was proposed,with N,N,N’,N’-tetraoctyl diglycolamide(TODGA)as the extractant,tri-n–butyl phosphate(TBP)as the phase modifier and 2,6-bis[1-(propan-1-ol)-1,2,3-triazol-4-yl]pyridine(PyTri-Diol or PTD)as hydrophilic stripping agent.This‘hot test’was successfully carried out,achieving 99.92%removal of americium-241(^(241)Am)with a separation factor SF(Eu/Am)of 3.8×10^(3)in the actinide(Ⅲ)product solution.The results show that bisamide podand extractants can effectively realize the extraction and separation of actinide(Ⅲ)and lanthanum(Ⅲ)from Chinese commercial HLLW and thus have a bright practical application potential for the treatment of commercial HLLW.
文摘The extraction and stripping of scandium from its sulfate solutions by isopropyl phosphonic acid mono (1-hexyl-4-ethyl) octyl ester (PT-2, HL) diluted with n-hexane are reported. A high efficiency of separation between scandium, iron and lutetium can be achieved by controlling aqueous acidity. Different mechanisms of Sc3+ with PT-2 in various acid range have been proposed.At lower aqueous acidity, it is a cation exchange reaction, while at higher acidity. a solvation reaction was ascertained. Its IR and NMR spectra have been discussed. The effect of temperature on extraction of Sc3+ was observed and thermodynamic functions were calculated.
基金Project supported by the National Natural Science Foundation of China(21876062)Shandong Provincial Natural Science Foundation(ZR2022QB067)。
文摘Rational design of extractant structure to improve the extraction and separation capacity of rare earth elements(REEs)is a long-standing challenge.Herein,a new strategy was proposed to improve the stability of the chelating structure formed by malonamide and REEs.The stability of the chelating structure is greatly improved by using a double-ring framework structure which makes the two carbonyl groups of malonamide unable to rotate freely and both of them point to the metal ion position.Three benzyl groups were used to construct the hydrophobicity of the extractant and the organic shell of the extracted species.Tribenzylhexahydro-pyrrolo-pyridine-dione(THPPD)was designed and synthesized.The structure reduces the energy consumed by rotating carbonyl group in the coordination with metal ions and then improves the extraction ability of extractant.The crystal structure was preorganized as expected,with the two carbonyls pointing in a favorable coordination direction to the structural complement of the metal ion.The extraction behaviors of REEs with THPPD in a nitric acid medium were studied.Compared with N,N’-dibenzyl-N,N’-dimethylmalonamide(DBDM-MA)with a chain structure,the extraction capacity of THPPD is 360 times higher than that of DBDM-MA at 5.0 mol/L sodium nitrate.Furthermore,the binding energy and Gibbs free energy were investigated by density functional theory(DFT)in conjunction with the B3LYP.The theoretical results show that THPPD has more effective interaction with Pr(NO_(3))3 than DBDM-MA.The construction of chelating groups conformation is a worthy direction to improve the coordination ability and even selectivity of extractant.
基金Project supported by the National Basic Research Program(973 Program)(2006CB403302)
文摘This paper reviewed various systems such as neutral phosphorus and acid phosphorus, carboxylic acid and amine extractant for solvent extraction chemistry of yttrium, including thermodynamics, kinetics and yttrium extracting separation process containing the development course and new separation process.
文摘Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution of monomyristyl phosphoric acid (MPA) in chloroform.Mineral acids are used as developers. The effect of concentration of acids and/or salts upon R_f has been investigated.According to the re- sults of R_f values for a given rare earth element in various acids,the order of extraction ability is HCl>HNO_3>H_2SO_4.A tetrad effect is clearly observed.for the R_f value of rare earth elements.The effects of other parameters on the R_f value,such as the quantities of extractant retained by the paper and the temperature are also examined.Based on the determination of the molar ratio of MPA to rare earth elements and the number of H^+ ions released in extraction reaction,a reasonable mechanism is proposed.The mutual separation of heavy rare earth elements will be better than that of the light rare earth group because of the larger separation coefficient of the former.A mixture of Ho-Er-Tm-Lu is successfully separated by the present method.
文摘Separation technology of rare earth elements （REEs）, as the critical step in the separation process, had long been fraught with technical difficulty. A research project conducted by Baotou Shibo Rare Earth Extraction ＆ Equipment Co. Ltd., Baotou REE Research Institute, and Baotou Steel ＆ REE Group Hi-Tech Co. Ltd （Inner Mongolia）, has successfully solved the problem using a centrifugal extractor and advanced techniques to achieve a key breakthrough.
基金Project(2010ZX07212-008) supported by the Major Science and Technology Program for Water Pollution Control and Treatment the China Molybdenum Co., Ltd.for financial support
文摘An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo was studied. The precursor solution was obtained via evaporation deamination and H202-complex transformation processes. Then it was extracted with a mixture extractant of tri-alkyl phosphine oxide （TRPO） and tributyl phosphate （TBP） to separate Mo and W. The results indicated that the evaporation deamination complex method reduced the acid consumption by more than 90% in comparison with the traditional directly acid regulation complex method. The transformation rates of W and Mo were higher than 95% and the decomposition rate of H202 was less than 15% at a 1.8-1.9 times H202 dosage, 45-50 ℃, initial pH of 1.80-1.90, and transformation volume ratio of 100% for 60 min in the H2O2-complexation transformation process. The minimum extraction rate of W was 2%, the maximum extraction rate of Mo was 82.6% and the highest separation coefficient was 76.7 in a single-stage extraction.
基金National Natural Science Foundation of China(22078166)Taishan Scholar Constructive Engineering Foundation(tsqn202211163).
文摘tert-butanol and ethyl acetate,as fuel additives and oxygenated fuels,can improve fuels quality and reduce exhaust emissions.Therefore,the recovery of these compounds from azeotropic systems is of great significance.Ionic liquids(ILs)are promising green solvents for separating azeotropic systems.In this study,an efficient extraction strategy based on 1-butyl-3-methylimidazolium acetate([Bmim][AC])is proposed.The mechanism by which ILs enable the separation of binary alcohol-ester azeotropes was revealed by evaluating the lowest conformational energy through combining an independent gradient model based on the Hirshfeld partition(IGMH)and frontier molecular orbitals,to preliminarily screen the extractants.The range of extractants was further reduced by a vapor–liquid phase equilibrium(VLE)experiment,and a modeling method for separating the alcohol–ester system and recovering the solvent using[Bmim][AC]and 1-ethyl-3-methyl-3-imidazolium acetate([Emim][AC])is established.Under the optimal operating conditions,the use of[Bmim][AC]can reduce the total annual cost(TAC)per year by 17.78%,and the emissions of CO_(2),SO_(2),and NO can be reduced by 10.86%.In this study,a comprehensive method for screening extractants is proposed,and the simulation process is optimized in combination with the economic and environmental impact.The results have important guiding significance for realizing efficient,energy-saving,and green azeotropic separation systems in industry.
基金Supported by the National Natural Science Foundation of China(No.20777029)Department of Education Project of Jilin Province,China(No.20070156)
文摘A new method to extract and separate tetracycline（TC） in a new aqueous tyro-phase system（ATPS） consisting of hydrophilic [Bmim]BF4 and NaH2PO4 was investigated. The effects of the amount of salt, ionic liquid as well as tetracycline on extraction efficiency were studied systematically. The results show that ionic liquid-ATPS exhibited the highest extraction efficiency higher than 90%. When the concentration of NaH2PO4 was 33.3%--38.5% （mass fraction）, the amounts of ionic liquid and TC were 1.0--2.0 mL and 1.8 mL, respectively, and ionic liquid could be re-used.
基金Project supported by the National High Technology Research and Development Program of China (2010AA03A405)the Key Program of National Natural Science Foundation of China (50934004)
文摘In view of the problem of ammonia-nitrogen wastewater pollution in rare earths extraction and separation, the novel saponification agent of organic phase, which is magnesium bicarbonate solution, was prepared with the natural rich and cheap dolomite as raw material through carbonation process. The behavior and purification of main impurities ions in the carbonation process as well as the application effect of the novel saponification agent in the extraction and separation was researched. The results showed that the concentration of Fe, A1, Si im- purities ions was.less than 5 ppm in the saponification agent through the development of effective removal technology, respectively. When the novel saponification agent was used in the extraction and separation, magnesium utilization rate was more than 95%, and rare earths extrac- tion rate above 99.5% has achieved. Therefore, the technology could replace ammonia-water to saponify the organic phase in rare earth ex- traction and separation process.
基金financed by the project supported by the National Natural Science Foundation of China(22078266,21908180,22178289,22278338)the Key Research and Development Program of Shaanxi(2020ZDLGY11-02,2021GY-136)the Special Fund for High-level Scholars of China(XJ21B10)。
文摘The low temperature coal tar(CT)is taken as the raw material,and the extraction and column chromatography are used for detailed and accurate characterization in this paper.The n-heptane soluble fraction(CT-HS)and insoluble fraction(CT-HI)were obtained by n-heptane Soxhlet extraction.The extraction rate of CT-HS reached 92.79%(mass),which indicated that there are few heavy compounds in it.Further,different solvents(methylbenzene,benzene,ethyl acetate,methylbenzene-ethanol)were used to elute CT-HS by chromatographic column to obtain five fractions(saturates,aromatics,heteroatoms,phenolics and resins,named CT-SA,CT-AR,CT-HE,CT-PH,CT-RE,respectively).The yields of CTSA,CT-AR,CT-HE,CT-PH,CT-RE are 42.12%,10.43%,2.19%,9.50%and 6.63%(mass),respectively.Gas chromatography-mass spectrometry analysis of eluting components show that alkanes are the main components in CT,followed by polycyclic aromatics,and the corresponding fractions are CT-SA and CT-AR,respectively.The relative content of aliphatics in CT-SA is 76.93%,and the relative content of aromatics in CT-AR is 75.05%.This separation technology effectively separates and enriches different components in CT,and the activation energy required for the pyrolysis process of a single eluting fraction is lower than that of CT,which is expected to provide an important reference for the separation,analysis and conversion of complex oil products such as coal-oil co-processing products,coal tar and other complex heavy carbon oil products.
基金supported by the National Natural Science Foundation of China(Nos.21472194,21701073 and 21772202)the Fundamental Research Funds for the Central Universities(No. lzujbky-2017-12)
文摘China is a major producer of rhenium, which is widely used in aerospace technologies （as superalloy） and petrochemical industries （as catalyst）. There is a gap between the demand and fact for the enrichment of rhenium, due to its rather small content （10-9） in the earth＇s crust. Also, there is no available single occurrence of mineral rhenium. Instead, the rhenium is associated with either molybdenum or copper （of up to 0.2% in content） as a by-product in metallurgical industry. This makes the separation of rhenium from the major mineral metals a challenge. The recent progresses in the separation and enrichment of rhenium were reviewed in this paper, especially, the advances in China. The details of varied separation methods used either in laboratories or factories, such as ion-exchange, solvent extraction, separation utilizing extractive resins, liquid membrane, or novel materials, etc., were elaborated. Comparison of the different methods was disclosed and an outlook on the rhenium chemistry and industry in the future was brought forward.
文摘A number of epuilibrium data of single stage in the system (Nd-SM)Cl_3-HCl-H_2O-1mol/L HEHEHP-kerosence was determined On the basis of epuilibrium data, two mathematical describing extract epui-librium of Nd and Sm were developed.The models cover wide available ranges (the total RE concentration inepuilibrated apueous phase is 0. 07～0. 77 mol/L and the acidity is 0. 11～0. 48 mol/L; the mole fraction ofMd or Sm is 0. 020～0. 998) with small average relative errors(The model of Nd is 6. 11 % and the model ofSm is 3. 07 %, respectively ) With the developed models, the extract behaviors of Nd and sM, such as thedistribution of rare earth concentrations in both phase, the effects of acidity, RE concentration, mole fractionof RE in aqueous phase on the RE concentration in organic phase, were researched The separation circuits be-tween Nd and Sm simulated and performed by the experiments in laboratory. The purities obtained prod-uct of Nd_2O_3O_3 as well as Sm_2O_3 were higher than 99%.Two calculation programs were written in BASIC language. One of them is used for publishing epuilibri-um model and another is used for simulation of fractional solvent extraction. The amulation results obtainedmay serve as a reference for designing solvent extraction process.
基金financially supported by the National Natural Science Foundation of China (52174336)the Natural Science Foundation of Shandong Province (ZR2021MB051)。
文摘In recent years,with the rapid developme nt of the econo my and society,pollution of valuable metal ions in wastewater has become a major challenge to environmental sustainability.In order to solve the pollution caused by metal ions,researchers have conducted continuous re searches and explored various re mediation methods.Crown ether has attracted great attention because of its ionic radius and cavity size matching well with metal ions,which makes it have the ability to selectively complex metal ions.This unique property enables the directed removal and recovery of metal ions and makes crown ethers increasingly popular in extraction and separation processes.In this paper,the research progress of crown ethers in the extraction and separation of valuable metal ions was reviewed,with emphasis on the principles,extraction systems and the key factors affecting the extraction process.This study can provide some technical support for the application of separation and extraction of valuable metal ions by crown ether.
基金Project(50904031) supported by the National Natural Science Foundation of ChinaProject(2008E0049M) supported by the Natural Science Foundation of Yunnan Province,China+1 种基金Project(07Z40082) supported by the Science Foundation of the Education Department of Yunnan Province,ChinaProject(2007-16) supported by the Science Foundation of Kunming University of Science and Technology,China
文摘Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.
基金financial support from the Talent Support Fund of Tsinghua University (No. 413405001)
文摘The radioactivity of uranium in radioactive coal bottom ash（CBA） may be a potential danger to the ambient environment and human health. Concerning the limited research on the distribution and mode of occurrence of uranium in CBA, we herein report our investigations into this topic using a number of techniques including a five-step Tessier sequential extraction, hydrogen fluoride（HF） leaching, Siroquant（Rietveld） quantification, magnetic separation, and electron probe microanalysis（EPMA）. The Tessier sequential extraction showed that the uranium in the residual and Fe–Mn oxide fractions was dominant（59.1%and 34.9%, respectively）. The former was mainly incorporated into aluminosilicates,retained with glass and cristobalite, whereas the latter was especially enriched in the magnetic fraction, of which about 50% was present with magnetite（Fe_3O_4） and the rest in other iron oxides. In addition, the uranium in the magnetic fraction was 2.6 times that in the non-magnetic fraction. The experimental findings in this work may be important for establishing an effective strategy to reduce radioactivity from CBA for the protection of our local environment.
文摘A multi-objective decision procedure was proposed to select the optimal precase parameters of extractionseporating zirconium and hafnium from sulphuric acid solution with Alamine-336 as an extractant in this pa-per.Adaptive Random Search(ARS) algorithm was adopted for optimizing calculation. The results obtainedshow that the multi-objective decision method is much better than sangle-objecive decision method.
基金Supported by Guangxi Science and Technology Research Project(Guikegong1346008-4)Guangxi Natural Science Foundation Project(2014GXNSFA A118271)
文摘[Objectives] Chemical compositions of S. carthamoides root were isolated and identified. [Methods]Solvent extraction,repeated silica gel column chromatography,ODS column chromatography,preparative liquid chromatography and recrystallization were used for separation and purification,and chemical structure of compound was identified via its physical-chemical properties and spectral analysis data.[Results] Eight compounds were obtained from methanol extract of S. carthamoides root: 24-ethyl-20-oxhydryl ecdysone( 1),β-ecdysterone( 2),Ajugasterone C( 3),3,4-DHBA( 4),3-methoxy-quercetin( 5),( 7 S,8 S)-syringoylglycerol( 6),( E)-3,7-dimethyl-1-O-[α-L-arabinofuranosyl-( 1→6)-β-D-glucopyranosy1]-oct-2-en-7-ol( 7),Polypodine B( 8). [Conclusions] Compounds 6 and 7 were firstly isolated from the plant.
