Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and ...Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.展开更多
The gas transport properties of both single and mixed gas systems including CH_(4),CO_(2),N_(2),C_(2)H_(6),and helium(He)were investigated using novel polymer membranes fabricated via solution casting from organic sol...The gas transport properties of both single and mixed gas systems including CH_(4),CO_(2),N_(2),C_(2)H_(6),and helium(He)were investigated using novel polymer membranes fabricated via solution casting from organic solvents.The fluorinated polytriazole polymers were synthesized through a polycondensation method incorporating hexafluoroisopropylidene the main polymer backbone,with various fluorinated aniline derivatives as side chains.It was observed that the bulky fluorinated aniline derivative groups such as 4-fluoroaniline,2,5-difluoroaniline,4-bromo-2,5-difluoroaniline,and 2,3,4,5,6-pentafluoroaniline significantly influenced the gas separation performance of the polymer membranes,particularly in terms of permeability and selectivity.The membranes exhibited excellent mechanical stability across a wide range of pure CO_(2) feed pressures(100—800 psi,1 psi=6.895 kPa)without signs of plasticization,highlighting their robustness for high-pressure applications.Additionally,the polymer synthesis process is reproducible and can be readily scaled,with each material displaying high solubility in organic solvents such as dimethyl acetamide,chloroform,and N-methyl pyrrolidone.Compared to gases such as CH_(4),N_(2),and C_(2)H_(6),the newly developed polymer membranes demonstrated superior permeability for CO_(2) and He under upstream feed pressures of up to 800 psi.These materials represent a completely novel class of polymer membranes tailored for advanced gas purification technologies.Their enhanced separation performance,particularly for CO_(2) removal and He recovery from natural gas streams at high processing pressures,positions them as promising candidates for industrial applications in gas purification and separation.展开更多
[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 （pUBH5）. [Method] Through the systemic pretreatment, preliminary chrom...[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 （pUBH5）. [Method] Through the systemic pretreatment, preliminary chromatography and fine chromatography. [Result]The optimized separation and purification conditions were that： Supernatant was treated by trichloroacetic acid, then by ultrafiltration desalt and anion exchange chromatography. Strong anion Q F. F. was better than weak anion DEAE F.F. The proper balanced solution was Tris-HCI （ pH 8.0）. The proper conductivity was 6 ms/cm. The maximum applied sample was 240 ATU/ml to matrix of strong anion Q F. F. This optimized procedure was magnified in strong anion exchange HiPrep 16/10Q with the 90% recovery and 70.2% purity. The purification of gel filtration of Sephacryl S-100 to hirudin was not relative to flow rate within certain scope. The application size of sample was 10 ml. The purity checked by HPLC was 95.1%, and the recovery was 93%, and the band of SDS-PAGE was single. [ Conclusion] The research provided the reference of the further industrialization separation and purification of hiruin.展开更多
Deoxynivalenol（DON） is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo a...Deoxynivalenol（DON） is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water（84：16, v/v）. A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography（preparative HPLC） to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol（17：1, v/v）, which provided a good elution effect selected on thin layer chromatography（TLC）. The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry（MS） and ~1H and ^（13）C nuclear magnetic resonance（NMR） spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.展开更多
[Objective] The aim was to separate and purify antioxidant endophytic fun- gi from Stevia leaves. [Method] Stevia leaves were used as materials for endophytic fungi screening and purification. Then, liquid culture was...[Objective] The aim was to separate and purify antioxidant endophytic fun- gi from Stevia leaves. [Method] Stevia leaves were used as materials for endophytic fungi screening and purification. Then, liquid culture was conducted to test fermented supernatant abilities of antioxidant, DPPH free radical clearing and chemilumines- cence inhibition. [Result] Forty two endophytic fungi were separated from F01 to F42. F41 was proved to be the strongest in antioxidant aspect; F37 was the strongest in DPPH clearing; F02, F07, F20, F25, F37, and F416 stood out in a comprehensive comparison of the above aspects. Flow injection chemiluminescenct method was used to test the above six fermentation liquors, and the results showed that antioxidant abilities of the six were quite strong for all of chemiluminescence rates were over 70%. Through preliminary morphological identification, bacterial colony was found white or yellowy and only F02 was of dissepiment. [Conclusion] Fungi with high-antioxidation activities were separated, which paved the way for future research.展开更多
Oxygen diffusion and oxygen selective adsorption properties of rare earths material YBa_2Cu_3O_(7-x) (YBCO) were investigated by thermogravimetric, oxygen static adsorption and selectivity adsorption experiments. The ...Oxygen diffusion and oxygen selective adsorption properties of rare earths material YBa_2Cu_3O_(7-x) (YBCO) were investigated by thermogravimetric, oxygen static adsorption and selectivity adsorption experiments. The results show that YBCO is a very good deoxidizing material. The oxygen desorption of YBCO begins remarkably at about 400 ℃, mass loss can arrive at 1.2% of its original quantity at 800 ℃. Oxygen can be completely absorbed back into the sample again when temperature descends to 400 ℃. The oxygen adsorption selectivity, reproducibility and oxygen adsorption under very low oxygen partial pressure make the material desirable for air separation and gas purification. High purity nitrogen gas was produced with the YBCO molecular sieves in the air separation and gas purification experiments. 0.017 m^3 of high purity nitrogen (>99.9999%) can be obtained with 1 kg YBCO molecular sieve in one cycle. As a deoxidant, an obvious advantage of YBCO is that no hydrogen is needed in its applications.展开更多
Hydrogen separation and purification are two important chemical processes in the extensive application of hydrogen energy. Membrane technology has opened up a potential solution to the problems of separation and purif...Hydrogen separation and purification are two important chemical processes in the extensive application of hydrogen energy. Membrane technology has opened up a potential solution to the problems of separation and purification in an energy effective way. Membranes of adequate hydrogen permeability, good thermal and mechanical stability are the key to successful application of membrane technology in hydrogen separation and purification. In this paper, the relative parameters concerning hydrogen permeability, the development of different types of membranes namely: palladium composite membranes; V-based alloy membranes, specific functionality embraced alloy membranes, metal hydride (MH) thin films and fabrications, were reviewed and discussed. Pd-free membranes are found to be the ideal alternatives. Suitable MH thin films with mono- or multi-layer microstructures produced by novel fabrication techniques, is likely to be the promising candidates due to possessing properties distinct from those of bulk materials in membrane form.展开更多
The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic...The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic properties were also analyzed.The experimental results indicated that 28% and 56% (NH4)2SO4 saturation could separate the activated protease from the pepsin extract of gastric mucosa of Sheatfish (Silurus soldatovi) ;compared with the homogenate extraction,the pepsin specific activity of purified extraction by Sephadex G-75 gel chromatography system increased 598 fold,was 5 times higher than that of activated liquid,and the total production rate was 10.1%.The purified pepsin liquor at the conditions of pH3.3 0.01 M alanine-formic acid buffering solution,60 cm chromatography column,and the flowing rate of 0.8 ML/min was analyzed by SDS-PAGE,which indicated that there were two bands and the molecular weight was 34.0 kDa and 40.4 kDa,respectively.There were two peaks in the enzyme activity determination of the separated collecting liquor in gel chromatography,and the SDS-PAGE showed the concentrations of the two proteins was different,which indicated that it existed at least two pepsins in the gastric mucosa of Sheatfish (Silurus soldatovi).展开更多
In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, ...In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, 3 × YP ＋ 6% glucose, SC-URA 2% galactose, and SC-URA 2% galactose ＋ 5% NaCI glyeerol-3-phosphate dehydregenase, the cultured S. cerevisiaewas comminuted followed by full-automatic high-speed purification, and SDS-PAGE gel electrophoresis was performed for molecular weight of the GST fusion protein. The results showed that after shaking culture of the S. cerevisiae containing GCY1 at 25 ℃, the OD values of its 3 × YP ＋ 6% glucose culture and SC-URA 2% galaetose ＋ 5% NaC1 culture were 8.75 and 7.35, respectively. It was shown by purification with a Profinia low-pressure liquid chromatograph that only the S. cerevisiae cultured in SC-URA 2% galactose ＋ 5% NaC1 medium expressed glycerel-3-phosphate de- hydrogenase, the molecular weight of which was detected as 65 ku by SDS-PAGE gel electrophoresis.展开更多
[Objectives]To establish an efficient and environmentally friendly separation and purification method for the large-scale preparation of the major active components-eleutherol,eleutherine,and isoeleutherine-from the e...[Objectives]To establish an efficient and environmentally friendly separation and purification method for the large-scale preparation of the major active components-eleutherol,eleutherine,and isoeleutherine-from the ethnomedicinal plant Eleutherine americana Merr.et K.Heyne.[Methods]The sample of E.americana bulbs was initially extracted with ethanol,followed by three successive extractions with ethyl acetate-water(2:1,V/V)to obtain the target component-enriched fraction.Eight solvent systems were systematically optimized,and a mixture of petroleum ether-ethyl acetate-ethanol-water(5:5:6:4,V/V/V/V)was identified as the optimal solvent system for high-speed counter-current chromatography(HSCCC)separation under conditions of 900 rpm,2 mL/min,and 35℃.The crude HSCCC product was further purified by silica gel column chromatography(200-300 mesh)using gradient elution with a solvent system of n-hexane-dichloromethane-ethyl acetate(varying from 10:5:1 to 4:5:1,V/V/V).UPLC-PDA(Agilent SB-C_(18)column)and nuclear magnetic resonance spectroscopy(600 MHz)were comprehensively employed to assess compound purity and confirm molecular structures.[Results]An optimized technique integrating HSCCC and silica gel column chromatography was established,successfully enabling the large-scale preparation of three bioactive components:eleutherol(purity 99%),eleutherine(purity 98%),and isoeleutherine(purity 98%).Structural identification results were consistent with those reported in the literature.Compared to traditional methods,the new approach demonstrated improved separation efficiency and reduced solvent consumption.[Conclusions]The combined separation method utilizing HSCCC and silica gel column chromatography established in this study demonstrates notable advantages,including high efficiency,environmental friendliness,and cost-effectiveness,enabling the large-scale preparation of the three major active components from E.americana.This approach outperforms conventional methods by offering higher separation efficiency,reduced solvent consumption,and superior product purity,providing a robust technical solution for the development and utilization of bioactive compounds from E.americana.Moreover,it offers a novel methodological reference for the isolation and purification of other natural products.展开更多
Hydrogen is a green clean fuel and chemical feedstock. Its separation and purification from hydrogencontaining mixtures is the key step in the production of hydrogen with high purity(>99.99%). In this work, carbon ...Hydrogen is a green clean fuel and chemical feedstock. Its separation and purification from hydrogencontaining mixtures is the key step in the production of hydrogen with high purity(>99.99%). In this work, carbon molecular sieve(CMS) membranes with ultrahigh permselectivity for hydrogen purification were fabricated by high-temperature(700–900 ℃) pyrolysis of polymeric precursor of phenolphthaleinbased cardo poly(arylene ether ketone)(PEK-C). The evolution of the microstructural texture and ultramicroporous structure and gas separation performance of the CMS membrane were characterized via TG-MS, FT-IR, XRD, TEM, CO2 sorption analysis and gas permeation measurements. CMS membranes prepared at 700 ℃ exhibited amorphous turbostratic carbon structures and high H2 permeability of 5260 Barrer with H2/CH4, H2/N2 and H2/CO selectivities of 311, 142, 75, respectively. When carbonized at900 ℃, the CMS membrane with ultrahigh H2/CH4 selectivity of 1859 was derived owing to the formation of the dense and ordered carbon structure. CMS membranes with ultrahigh permselectivity exhibit an attractive application prospect in hydrogen purification.展开更多
Nano-Al13 was separated and purified by four methods to investigate its characteristic, and was analyzed by Al-Ferron timed complexation spectrophotometer, ^27Al-NMR （nuclear magnetic resonance）, and transmission el...Nano-Al13 was separated and purified by four methods to investigate its characteristic, and was analyzed by Al-Ferron timed complexation spectrophotometer, ^27Al-NMR （nuclear magnetic resonance）, and transmission electron microscopy （TEM）. Coagulation efficiency of nano-Al13, polyaluminum chloride （PAC）, and AlCl3 in synthetic water were also investigated by jar test. The dynamic process and aggregation state of kaolin suspensions coagulating with nano-Al13, PAC, and AlCl3 were also investigated. The experimental results indicated that the efficiency of gel column chromatography method was the highest for separating PAC solution with low Al concentration. Ethanol and acetone method was simple and could separated PAC solution with different Al concentrations, while silicon alkylation white block column chromatography method could separate PAC solution only with low Al concentration. The SO4^2-/Ba^2＋ displacement method could separate PAC solution with high Al concentration, but extra inorganic cation and anion could be introduced into the solution during the separation. The coagulation efficiency and dynamic experimental results showed that nano- Al13 with a high positive-charged species was the main species of electric neutralization in coagulation process, and it could reduce the turbidity and increase the effective particles collision rate efficiently in coagulation process. Its coagulation speed and the particle size of coagulant formed were of greatest value in this study.展开更多
A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective ...A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective of this study is to investigate general conditions,feed rate,distilling temperature and vacuum,necessary for centrifugal distillation of DC_(12).Under the optimum conditions,distilling temperature 180℃,pressure 30 Pa and feed flow rate700 ml·h^(-1),the purity of DC_(12) in the residence reached 97.55%with a yield of 53.18%by the analysis of gas chromatography.Multiple-pass distillation made a considerable contribution by improving the purity to99.22%.Additionally,the effect of pretreatment(re-crystallization) on distillation process was revealed through a series of comparative experiments.展开更多
The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate im...The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.展开更多
Decabromodiphenyl ethane(DBDPE)is widely used as an additive flame retardant and has led to global pollution.Its has a large molecular mass and is prone to debromination and degradation under photothermal conditions,r...Decabromodiphenyl ethane(DBDPE)is widely used as an additive flame retardant and has led to global pollution.Its has a large molecular mass and is prone to debromination and degradation under photothermal conditions,resulting in smaller homologous compounds.Due to the lack of standard substances for debromination products,the in-depth study of DBDPE environmental geochemical behavior through debromination conversion has been hindered.Therefore,based on DBDPE photodegradation experiment,this study first analyzed and identified the brominated products of DBDPE using high-performance liquid chromatography-atmospheric pressure photoionization-time of flight mass spectrometry(HPLC-APPI-TOF/MS).Four debromination products-nonabromodiphenyl ethane(nonaBDPE),octabromodiphenyl ethane(octa-BDPE),heptabromodiphenyl ethane(hepta-BDPE)and hexabromodiphenyl ethane(hexa-BDPE)are identified based on the characteristic ion peak of[M-Br+O]^(-) in negative ion mode.Subsequently,using methanol as the mobile phase,four debromination products of DBDPE were separated and purified with a semi-preparative high-performance liquid chromatography(SP-HPLC)system equipped with an Agilent Zorbax Eclipse PAH column(4.6 mm×250 mm,5μm).The first-time acquisition of hexa-BDPE(60.00μg),octa-BDPE(19.40μg),hepta-BDPE(31.20μg)and octa-BDPE(isomer,45.20μg)with purity exceeding 90%has been achieved.Among them,the purity of one hepta-BDPE monomer is as high as 98.91%.This study indicates that based on photodegradation experiments,the combination of HPLC-APPI-TOF/MS and SP-HPLC techniques can rapidly identify and prepare DBDPE debrominated products.This approach meets the requirements for preliminary research on the pollution characteristics of DBDPE debrominated compounds and offers a feasible solution for the preparation of standard reference materials for emerging pollutants.展开更多
Magnesium(Mg)is globally abundant in resources,and Mg‐based compounds—such as magnesium based hydrides,hydroxides,oxides,and magnesium metal‐organic frameworks(Mg MOFs)—have shown significant application prospects...Magnesium(Mg)is globally abundant in resources,and Mg‐based compounds—such as magnesium based hydrides,hydroxides,oxides,and magnesium metal‐organic frameworks(Mg MOFs)—have shown significant application prospects in gas separation.This is largely due to the electronic characteristics of Mg or Mg^(2+)ions,which facilitate the capture of hydrogen(H_(2))and acidic gases such as carbon dioxide(CO_(2))and sulfur dioxide(SO_(2))from other gases.Consequently,exploring the use of Mgbased materials in gas separation and purification applications could not only advance the scientific understanding of solid‐gas interaction mechanisms but also provide cost‐effective solutions for gas separation technology at an industrial level.This review summarizes the recent practices and explorations of Mg‐based solid‐state materials in various gas separation and purification methods,including physical adsorption‐based separation,chemical absorption‐based separation,and membrane‐based separation.For each separation method,the relevant Mg‐based materials are discussed in detail,and key findings from existing research are presented and analyzed.Additionally,inspired by the straightforward design of air‐stable hydrogen storage materials,this review specifically addresses anti‐passivation strategies for Mg‐based hydrides,which are crucial for their applications in hydrogen gas separation and purification.Finally,this review highlights key issues and fields for future research and development in Mg‐based gas separation materials.展开更多
The polysaccharides from Sepia esculenta ink are potential candidates for biomedical applications due to their functional properties.In our study,a heteropolysaccharide,SE-1,isolated from Sepia esculenta ink,had a mol...The polysaccharides from Sepia esculenta ink are potential candidates for biomedical applications due to their functional properties.In our study,a heteropolysaccharide,SE-1,isolated from Sepia esculenta ink,had a molecular weight of 13.1 kDa and a monosaccharide composition of Man:GlcN:GlcUA:GalN:Xyl:Fuc=1.00:1.38:0.65:2.89:0.76:1.99.Through partial acid hydrolysis,me-thylation and one-and two-dimensional nuclear magnetic resonance(1D and 2D NMR)spectroscopic analyses,it is indicated that the structure of SE-1 consists of→4)-α-D-GlcpNAc-(1→,→4)-α-L-Fucp-(1→,→3)-α-D-GalpNAc-(1→,→2,6)-α-D-Manp-(1→and→3)-β-D-GlcpUA-(1→as the main chain and single terminalβ-D-Xylp-(1→,which links to O-2 of(1→2,6)-α-Manp,as the side chain.A new aminosugar-abundant heteropolysaccharide was isolated from S.esculenta ink for the first time.展开更多
Due to the increasing global demand for industrial gas, the development of large-scale cryogenic air separation systems has attracted considerable attention in recent years. Increasing the height of the adsorption bed...Due to the increasing global demand for industrial gas, the development of large-scale cryogenic air separation systems has attracted considerable attention in recent years. Increasing the height of the adsorption bed in a vertical radial flow adsorber used in cryogenic air separation systems may efficiently increase the treatment capacity of the air in the adsorber. However, uniformity of the flow distribution of the air inside the adsorber would be deteriorated using the height-increasing method. In order to reduce the non-uniformity of the flow distribution caused by the excessive height of adsorption bed in a vertical radial flow adsorber, a novel parallel connection method is proposed in the present work. The experimental apparatus is designed and constructed; the Computational Fluid Dynamics(CFD) technique is used to develop a CFD-based model, which is used to analyze the flow distribution, the static pressure drop and the radial velocity in the newly designed adsorber. In addition, the geometric parameters of annular flow channels and the adsorption bed thickness of the upper unit in the parallelconnected vertical radial flow adsorber are optimized, so that the upper and lower adsorption units could be penetrated by air simultaneously. Comparisons are made between the height-increasing method and the parallel connection method with the same adsorber height. It is shown that using the parallel connection method could reduce the difference between the maximum and minimum radial static pressure drop by 86.2% and improve the uniformity by 80% compared with those of using the height-increasing method. The optimal thickness ratio of the upper and lower adsorption units is obtained as 0.966, in which case the upper and lower adsorption units could be penetrated by air simultaneously, so that the adsorbents in adsorption space could be used more efficiently.展开更多
China is the global leader in rare earth （RE） production using hydrometallurgical processes. Advantageous extraction techniques of rare earths from Baotou mixed rare earth minerals, bastnaesite, and ion-adsorption c...China is the global leader in rare earth （RE） production using hydrometallurgical processes. Advantageous extraction techniques of rare earths from Baotou mixed rare earth minerals, bastnaesite, and ion-adsorption clays of rare earth deposits have been developed in China. The separation and purification technologies have also achieved rapid development. The industrial application processes for rare earth hydrometallurgy were summarized in the present paper. With the large demands and rapid development of rare earths, the issues of resources and environment are more prominent. This review gives an overview of the main processes that were developed in the past toward greener hydrometallurgy of rare earths in China. Based on the development of the rare earth industry, comprehensive utilization and cleaner production should still be focused on in the future, to support the sustainable development.展开更多
In this paper, the recent advance of processes for treating Baotou mixed-type rare earths concentrate, bastnasite, and ionic adsorption deposit in China was reviewed. The R & D circumstance and new progresses in s...In this paper, the recent advance of processes for treating Baotou mixed-type rare earths concentrate, bastnasite, and ionic adsorption deposit in China was reviewed. The R & D circumstance and new progresses in separation and purification of individual and high purity RE compounds in China were introduced. Moreover, the development of RE hydrometallurgy was also predicted. So we suggest to enhance the research and development of products applying RE, especially Ce, Y, Gd, Sm etc., for keeping RE consumption equilibrium and extending applications, to increase enterprise's automatic control level for improving the stability and the consistency of the products, and to pay more attention to protection of environment.展开更多
基金financially supported by the Original Exploration Project of the National Natural Science Foundation of China(No.52150079)the National Natural Science Foundation of China(Nos.U22A20130,U2004215,and 51974280)+1 种基金the Natural Science Foundation of Henan Province of China(No.232300421196)the Project of Zhongyuan Critical Metals Laboratory of China(Nos.GJJSGFYQ202304,GJJSGFJQ202306,GJJSGFYQ202323,GJJSGFYQ202308,and GJJSGFYQ202307)。
文摘Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.
文摘The gas transport properties of both single and mixed gas systems including CH_(4),CO_(2),N_(2),C_(2)H_(6),and helium(He)were investigated using novel polymer membranes fabricated via solution casting from organic solvents.The fluorinated polytriazole polymers were synthesized through a polycondensation method incorporating hexafluoroisopropylidene the main polymer backbone,with various fluorinated aniline derivatives as side chains.It was observed that the bulky fluorinated aniline derivative groups such as 4-fluoroaniline,2,5-difluoroaniline,4-bromo-2,5-difluoroaniline,and 2,3,4,5,6-pentafluoroaniline significantly influenced the gas separation performance of the polymer membranes,particularly in terms of permeability and selectivity.The membranes exhibited excellent mechanical stability across a wide range of pure CO_(2) feed pressures(100—800 psi,1 psi=6.895 kPa)without signs of plasticization,highlighting their robustness for high-pressure applications.Additionally,the polymer synthesis process is reproducible and can be readily scaled,with each material displaying high solubility in organic solvents such as dimethyl acetamide,chloroform,and N-methyl pyrrolidone.Compared to gases such as CH_(4),N_(2),and C_(2)H_(6),the newly developed polymer membranes demonstrated superior permeability for CO_(2) and He under upstream feed pressures of up to 800 psi.These materials represent a completely novel class of polymer membranes tailored for advanced gas purification technologies.Their enhanced separation performance,particularly for CO_(2) removal and He recovery from natural gas streams at high processing pressures,positions them as promising candidates for industrial applications in gas purification and separation.
基金Supported by 863 Program of China(2006AA03Z0453)NaturalScience Research Program of Higher Education of Jiangsu Province(09KJB230001)+1 种基金973 Program of China(2009CB724700)AndSchool Foundation of Jiangsu University(08JDG009)~~
文摘[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 （pUBH5）. [Method] Through the systemic pretreatment, preliminary chromatography and fine chromatography. [Result]The optimized separation and purification conditions were that： Supernatant was treated by trichloroacetic acid, then by ultrafiltration desalt and anion exchange chromatography. Strong anion Q F. F. was better than weak anion DEAE F.F. The proper balanced solution was Tris-HCI （ pH 8.0）. The proper conductivity was 6 ms/cm. The maximum applied sample was 240 ATU/ml to matrix of strong anion Q F. F. This optimized procedure was magnified in strong anion exchange HiPrep 16/10Q with the 90% recovery and 70.2% purity. The purification of gel filtration of Sephacryl S-100 to hirudin was not relative to flow rate within certain scope. The application size of sample was 10 ml. The purity checked by HPLC was 95.1%, and the recovery was 93%, and the band of SDS-PAGE was single. [ Conclusion] The research provided the reference of the further industrialization separation and purification of hiruin.
基金supported by the National Natural Science Foundation of China (31402268)the Natural Science Foundation of Jiangsu Province of China (BK20140691)+1 种基金Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), ChinaThe Introduction of International Advanced Agricultural Science and Technology Project from the Ministry of Agriculture of China (2012-Z22)
文摘Deoxynivalenol（DON） is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water（84：16, v/v）. A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography（preparative HPLC） to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol（17：1, v/v）, which provided a good elution effect selected on thin layer chromatography（TLC）. The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry（MS） and ~1H and ^（13）C nuclear magnetic resonance（NMR） spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.
基金Supported by National Natural Science Foundation of China(31060193)Starting Foundation of Scientific research in Guilin University of Technology~~
文摘[Objective] The aim was to separate and purify antioxidant endophytic fun- gi from Stevia leaves. [Method] Stevia leaves were used as materials for endophytic fungi screening and purification. Then, liquid culture was conducted to test fermented supernatant abilities of antioxidant, DPPH free radical clearing and chemilumines- cence inhibition. [Result] Forty two endophytic fungi were separated from F01 to F42. F41 was proved to be the strongest in antioxidant aspect; F37 was the strongest in DPPH clearing; F02, F07, F20, F25, F37, and F416 stood out in a comprehensive comparison of the above aspects. Flow injection chemiluminescenct method was used to test the above six fermentation liquors, and the results showed that antioxidant abilities of the six were quite strong for all of chemiluminescence rates were over 70%. Through preliminary morphological identification, bacterial colony was found white or yellowy and only F02 was of dissepiment. [Conclusion] Fungi with high-antioxidation activities were separated, which paved the way for future research.
基金Project supported by the Science and Technology of Henan Province (991110343)
文摘Oxygen diffusion and oxygen selective adsorption properties of rare earths material YBa_2Cu_3O_(7-x) (YBCO) were investigated by thermogravimetric, oxygen static adsorption and selectivity adsorption experiments. The results show that YBCO is a very good deoxidizing material. The oxygen desorption of YBCO begins remarkably at about 400 ℃, mass loss can arrive at 1.2% of its original quantity at 800 ℃. Oxygen can be completely absorbed back into the sample again when temperature descends to 400 ℃. The oxygen adsorption selectivity, reproducibility and oxygen adsorption under very low oxygen partial pressure make the material desirable for air separation and gas purification. High purity nitrogen gas was produced with the YBCO molecular sieves in the air separation and gas purification experiments. 0.017 m^3 of high purity nitrogen (>99.9999%) can be obtained with 1 kg YBCO molecular sieve in one cycle. As a deoxidant, an obvious advantage of YBCO is that no hydrogen is needed in its applications.
文摘Hydrogen separation and purification are two important chemical processes in the extensive application of hydrogen energy. Membrane technology has opened up a potential solution to the problems of separation and purification in an energy effective way. Membranes of adequate hydrogen permeability, good thermal and mechanical stability are the key to successful application of membrane technology in hydrogen separation and purification. In this paper, the relative parameters concerning hydrogen permeability, the development of different types of membranes namely: palladium composite membranes; V-based alloy membranes, specific functionality embraced alloy membranes, metal hydride (MH) thin films and fabrications, were reviewed and discussed. Pd-free membranes are found to be the ideal alternatives. Suitable MH thin films with mono- or multi-layer microstructures produced by novel fabrication techniques, is likely to be the promising candidates due to possessing properties distinct from those of bulk materials in membrane form.
基金Sponsored by the Key Research Program of Chinese Academy of Fishery Sciences (Grant No. 1999-01-10)Agricultural Science and Technology Fund of Department of Science and Technology (Grant No. 02EFN216900727)the National Natural Science Foundation of China (Grant No. 50638020)
文摘The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic properties were also analyzed.The experimental results indicated that 28% and 56% (NH4)2SO4 saturation could separate the activated protease from the pepsin extract of gastric mucosa of Sheatfish (Silurus soldatovi) ;compared with the homogenate extraction,the pepsin specific activity of purified extraction by Sephadex G-75 gel chromatography system increased 598 fold,was 5 times higher than that of activated liquid,and the total production rate was 10.1%.The purified pepsin liquor at the conditions of pH3.3 0.01 M alanine-formic acid buffering solution,60 cm chromatography column,and the flowing rate of 0.8 ML/min was analyzed by SDS-PAGE,which indicated that there were two bands and the molecular weight was 34.0 kDa and 40.4 kDa,respectively.There were two peaks in the enzyme activity determination of the separated collecting liquor in gel chromatography,and the SDS-PAGE showed the concentrations of the two proteins was different,which indicated that it existed at least two pepsins in the gastric mucosa of Sheatfish (Silurus soldatovi).
基金Supported by Social Service Project of New Countryside Development Research Institute of Yangtze University(201411)
文摘In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, 3 × YP ＋ 6% glucose, SC-URA 2% galactose, and SC-URA 2% galactose ＋ 5% NaCI glyeerol-3-phosphate dehydregenase, the cultured S. cerevisiaewas comminuted followed by full-automatic high-speed purification, and SDS-PAGE gel electrophoresis was performed for molecular weight of the GST fusion protein. The results showed that after shaking culture of the S. cerevisiae containing GCY1 at 25 ℃, the OD values of its 3 × YP ＋ 6% glucose culture and SC-URA 2% galaetose ＋ 5% NaC1 culture were 8.75 and 7.35, respectively. It was shown by purification with a Profinia low-pressure liquid chromatograph that only the S. cerevisiae cultured in SC-URA 2% galactose ＋ 5% NaC1 medium expressed glycerel-3-phosphate de- hydrogenase, the molecular weight of which was detected as 65 ku by SDS-PAGE gel electrophoresis.
基金Supported by Natural Science Foundation of Tibet Autonomous Region,Science and Technology Department of Tibet(XZ202501ZR0118).
文摘[Objectives]To establish an efficient and environmentally friendly separation and purification method for the large-scale preparation of the major active components-eleutherol,eleutherine,and isoeleutherine-from the ethnomedicinal plant Eleutherine americana Merr.et K.Heyne.[Methods]The sample of E.americana bulbs was initially extracted with ethanol,followed by three successive extractions with ethyl acetate-water(2:1,V/V)to obtain the target component-enriched fraction.Eight solvent systems were systematically optimized,and a mixture of petroleum ether-ethyl acetate-ethanol-water(5:5:6:4,V/V/V/V)was identified as the optimal solvent system for high-speed counter-current chromatography(HSCCC)separation under conditions of 900 rpm,2 mL/min,and 35℃.The crude HSCCC product was further purified by silica gel column chromatography(200-300 mesh)using gradient elution with a solvent system of n-hexane-dichloromethane-ethyl acetate(varying from 10:5:1 to 4:5:1,V/V/V).UPLC-PDA(Agilent SB-C_(18)column)and nuclear magnetic resonance spectroscopy(600 MHz)were comprehensively employed to assess compound purity and confirm molecular structures.[Results]An optimized technique integrating HSCCC and silica gel column chromatography was established,successfully enabling the large-scale preparation of three bioactive components:eleutherol(purity 99%),eleutherine(purity 98%),and isoeleutherine(purity 98%).Structural identification results were consistent with those reported in the literature.Compared to traditional methods,the new approach demonstrated improved separation efficiency and reduced solvent consumption.[Conclusions]The combined separation method utilizing HSCCC and silica gel column chromatography established in this study demonstrates notable advantages,including high efficiency,environmental friendliness,and cost-effectiveness,enabling the large-scale preparation of the three major active components from E.americana.This approach outperforms conventional methods by offering higher separation efficiency,reduced solvent consumption,and superior product purity,providing a robust technical solution for the development and utilization of bioactive compounds from E.americana.Moreover,it offers a novel methodological reference for the isolation and purification of other natural products.
基金the National Key R&D Program of China(2017YFB0603403)National Natural Science Foundation of China(21676044,21878033,21978034)+1 种基金High Level Innovation Team of Liaoning Province(XLYC1908033)Fundamental Research Funds for the Central Universities(DUT19ZD211,DUT 2018TB02)for the financial support。
文摘Hydrogen is a green clean fuel and chemical feedstock. Its separation and purification from hydrogencontaining mixtures is the key step in the production of hydrogen with high purity(>99.99%). In this work, carbon molecular sieve(CMS) membranes with ultrahigh permselectivity for hydrogen purification were fabricated by high-temperature(700–900 ℃) pyrolysis of polymeric precursor of phenolphthaleinbased cardo poly(arylene ether ketone)(PEK-C). The evolution of the microstructural texture and ultramicroporous structure and gas separation performance of the CMS membrane were characterized via TG-MS, FT-IR, XRD, TEM, CO2 sorption analysis and gas permeation measurements. CMS membranes prepared at 700 ℃ exhibited amorphous turbostratic carbon structures and high H2 permeability of 5260 Barrer with H2/CH4, H2/N2 and H2/CO selectivities of 311, 142, 75, respectively. When carbonized at900 ℃, the CMS membrane with ultrahigh H2/CH4 selectivity of 1859 was derived owing to the formation of the dense and ordered carbon structure. CMS membranes with ultrahigh permselectivity exhibit an attractive application prospect in hydrogen purification.
基金supported by the National Natural Sciences Foundation of China (No. 50678095)the Postdoctoral Innovative Projects of Shandong Province (No. 200703053).
文摘Nano-Al13 was separated and purified by four methods to investigate its characteristic, and was analyzed by Al-Ferron timed complexation spectrophotometer, ^27Al-NMR （nuclear magnetic resonance）, and transmission electron microscopy （TEM）. Coagulation efficiency of nano-Al13, polyaluminum chloride （PAC）, and AlCl3 in synthetic water were also investigated by jar test. The dynamic process and aggregation state of kaolin suspensions coagulating with nano-Al13, PAC, and AlCl3 were also investigated. The experimental results indicated that the efficiency of gel column chromatography method was the highest for separating PAC solution with low Al concentration. Ethanol and acetone method was simple and could separated PAC solution with different Al concentrations, while silicon alkylation white block column chromatography method could separate PAC solution only with low Al concentration. The SO4^2-/Ba^2＋ displacement method could separate PAC solution with high Al concentration, but extra inorganic cation and anion could be introduced into the solution during the separation. The coagulation efficiency and dynamic experimental results showed that nano- Al13 with a high positive-charged species was the main species of electric neutralization in coagulation process, and it could reduce the turbidity and increase the effective particles collision rate efficiently in coagulation process. Its coagulation speed and the particle size of coagulant formed were of greatest value in this study.
文摘A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective of this study is to investigate general conditions,feed rate,distilling temperature and vacuum,necessary for centrifugal distillation of DC_(12).Under the optimum conditions,distilling temperature 180℃,pressure 30 Pa and feed flow rate700 ml·h^(-1),the purity of DC_(12) in the residence reached 97.55%with a yield of 53.18%by the analysis of gas chromatography.Multiple-pass distillation made a considerable contribution by improving the purity to99.22%.Additionally,the effect of pretreatment(re-crystallization) on distillation process was revealed through a series of comparative experiments.
基金financially supported by the Special Project on the Integration of Industry, Education and Research of Guangdong Province, China (No. 20013A090100013)by the High Technology Research and Development Program of Xinjiang Uygur Autonomous Region of China (No. 201407300993)
文摘The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.
基金supported by the National Natural Science Foundation of China(Nos.42107284 and 22078177)the Postdoctoral Fellowship Program of CPSF(No.GZB20240410)。
文摘Decabromodiphenyl ethane(DBDPE)is widely used as an additive flame retardant and has led to global pollution.Its has a large molecular mass and is prone to debromination and degradation under photothermal conditions,resulting in smaller homologous compounds.Due to the lack of standard substances for debromination products,the in-depth study of DBDPE environmental geochemical behavior through debromination conversion has been hindered.Therefore,based on DBDPE photodegradation experiment,this study first analyzed and identified the brominated products of DBDPE using high-performance liquid chromatography-atmospheric pressure photoionization-time of flight mass spectrometry(HPLC-APPI-TOF/MS).Four debromination products-nonabromodiphenyl ethane(nonaBDPE),octabromodiphenyl ethane(octa-BDPE),heptabromodiphenyl ethane(hepta-BDPE)and hexabromodiphenyl ethane(hexa-BDPE)are identified based on the characteristic ion peak of[M-Br+O]^(-) in negative ion mode.Subsequently,using methanol as the mobile phase,four debromination products of DBDPE were separated and purified with a semi-preparative high-performance liquid chromatography(SP-HPLC)system equipped with an Agilent Zorbax Eclipse PAH column(4.6 mm×250 mm,5μm).The first-time acquisition of hexa-BDPE(60.00μg),octa-BDPE(19.40μg),hepta-BDPE(31.20μg)and octa-BDPE(isomer,45.20μg)with purity exceeding 90%has been achieved.Among them,the purity of one hepta-BDPE monomer is as high as 98.91%.This study indicates that based on photodegradation experiments,the combination of HPLC-APPI-TOF/MS and SP-HPLC techniques can rapidly identify and prepare DBDPE debrominated products.This approach meets the requirements for preliminary research on the pollution characteristics of DBDPE debrominated compounds and offers a feasible solution for the preparation of standard reference materials for emerging pollutants.
基金supported by National Key Research&Development Program of China(2023YFB3809103 and 2023YFB3809100)National Natural Science Foundation of China(52201266,52171186)+1 种基金Startup Fund for Young Faculty at SJTU(SFYF at SJTU)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001).
文摘Magnesium(Mg)is globally abundant in resources,and Mg‐based compounds—such as magnesium based hydrides,hydroxides,oxides,and magnesium metal‐organic frameworks(Mg MOFs)—have shown significant application prospects in gas separation.This is largely due to the electronic characteristics of Mg or Mg^(2+)ions,which facilitate the capture of hydrogen(H_(2))and acidic gases such as carbon dioxide(CO_(2))and sulfur dioxide(SO_(2))from other gases.Consequently,exploring the use of Mgbased materials in gas separation and purification applications could not only advance the scientific understanding of solid‐gas interaction mechanisms but also provide cost‐effective solutions for gas separation technology at an industrial level.This review summarizes the recent practices and explorations of Mg‐based solid‐state materials in various gas separation and purification methods,including physical adsorption‐based separation,chemical absorption‐based separation,and membrane‐based separation.For each separation method,the relevant Mg‐based materials are discussed in detail,and key findings from existing research are presented and analyzed.Additionally,inspired by the straightforward design of air‐stable hydrogen storage materials,this review specifically addresses anti‐passivation strategies for Mg‐based hydrides,which are crucial for their applications in hydrogen gas separation and purification.Finally,this review highlights key issues and fields for future research and development in Mg‐based gas separation materials.
基金funded by the Natural Science Founda-tion of Zhejiang Province,China(No.LTGS23D060001)the Scientific Research Foundation for the Introduc-tion of Talent of Zhejiang Ocean University(No.JX6311130823).
文摘The polysaccharides from Sepia esculenta ink are potential candidates for biomedical applications due to their functional properties.In our study,a heteropolysaccharide,SE-1,isolated from Sepia esculenta ink,had a molecular weight of 13.1 kDa and a monosaccharide composition of Man:GlcN:GlcUA:GalN:Xyl:Fuc=1.00:1.38:0.65:2.89:0.76:1.99.Through partial acid hydrolysis,me-thylation and one-and two-dimensional nuclear magnetic resonance(1D and 2D NMR)spectroscopic analyses,it is indicated that the structure of SE-1 consists of→4)-α-D-GlcpNAc-(1→,→4)-α-L-Fucp-(1→,→3)-α-D-GalpNAc-(1→,→2,6)-α-D-Manp-(1→and→3)-β-D-GlcpUA-(1→as the main chain and single terminalβ-D-Xylp-(1→,which links to O-2 of(1→2,6)-α-Manp,as the side chain.A new aminosugar-abundant heteropolysaccharide was isolated from S.esculenta ink for the first time.
基金Supported by the National Key R&D Program of China(2017YFB0603702)the Natural Science Foundation of Zhejiang Province(Y15E060014)+1 种基金the National Natural Science Foundation of China(51636007)Shanghai Young Teachers Development Program(10-16-301-801)
文摘Due to the increasing global demand for industrial gas, the development of large-scale cryogenic air separation systems has attracted considerable attention in recent years. Increasing the height of the adsorption bed in a vertical radial flow adsorber used in cryogenic air separation systems may efficiently increase the treatment capacity of the air in the adsorber. However, uniformity of the flow distribution of the air inside the adsorber would be deteriorated using the height-increasing method. In order to reduce the non-uniformity of the flow distribution caused by the excessive height of adsorption bed in a vertical radial flow adsorber, a novel parallel connection method is proposed in the present work. The experimental apparatus is designed and constructed; the Computational Fluid Dynamics(CFD) technique is used to develop a CFD-based model, which is used to analyze the flow distribution, the static pressure drop and the radial velocity in the newly designed adsorber. In addition, the geometric parameters of annular flow channels and the adsorption bed thickness of the upper unit in the parallelconnected vertical radial flow adsorber are optimized, so that the upper and lower adsorption units could be penetrated by air simultaneously. Comparisons are made between the height-increasing method and the parallel connection method with the same adsorber height. It is shown that using the parallel connection method could reduce the difference between the maximum and minimum radial static pressure drop by 86.2% and improve the uniformity by 80% compared with those of using the height-increasing method. The optimal thickness ratio of the upper and lower adsorption units is obtained as 0.966, in which case the upper and lower adsorption units could be penetrated by air simultaneously, so that the adsorbents in adsorption space could be used more efficiently.
基金financially supported by the National Natural Science Foundation of China(Nos.50934004 and 51404035)
文摘China is the global leader in rare earth （RE） production using hydrometallurgical processes. Advantageous extraction techniques of rare earths from Baotou mixed rare earth minerals, bastnaesite, and ion-adsorption clays of rare earth deposits have been developed in China. The separation and purification technologies have also achieved rapid development. The industrial application processes for rare earth hydrometallurgy were summarized in the present paper. With the large demands and rapid development of rare earths, the issues of resources and environment are more prominent. This review gives an overview of the main processes that were developed in the past toward greener hydrometallurgy of rare earths in China. Based on the development of the rare earth industry, comprehensive utilization and cleaner production should still be focused on in the future, to support the sustainable development.
基金Project supported by the National Science Foundation of China (50374015)
文摘In this paper, the recent advance of processes for treating Baotou mixed-type rare earths concentrate, bastnasite, and ionic adsorption deposit in China was reviewed. The R & D circumstance and new progresses in separation and purification of individual and high purity RE compounds in China were introduced. Moreover, the development of RE hydrometallurgy was also predicted. So we suggest to enhance the research and development of products applying RE, especially Ce, Y, Gd, Sm etc., for keeping RE consumption equilibrium and extending applications, to increase enterprise's automatic control level for improving the stability and the consistency of the products, and to pay more attention to protection of environment.
