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Recovery of rare earths from ion-absorbed rare earths ore with MgSO_4-ascorbic acid compound leaching agent

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Journal of Rare Earths 2018年第5期36卷 521-527页

作者： Fuguo Lai Li Huang guohua gao Run Yang Yanfei Xiao School of Metallurgical and Chemical Engineering Jiangxi University of science and Technology Ganzhou 341000 China Institute of Engineering ＆ Research Jiangxi University of Science and Technology Ganzhou 341000 China

The magnesium sulfate leaching technology for the ion-absorbed rare earths ore can solve the ammonia pollution problem existing in ammonium sulfate leaching process. However, the leaching capacity of magnesium sulfate is slightly weaker than that of ammonium sulfate, resulting in a bigger consumption of magnesium sulfate. In this paper, the MgSO4-ascorbic acid compound leaching agent had been demonstrated to deal with the ion-absorbed rare earths ore. The ascorbic acid could form a stable coordination with rare earth ions, so that it can strengthen the leaching of ion-exchangeable ***, ascorbic acid has a strong reductive property, it can leach the colloidal sediment phase rare earth as well. The present study investigates the effect of the initial pH and the composition of leaching agent on the rare earth leaching. It is determined that the rare earth leaching efficiency is 107.5% under the condition of pH 2.00,0.15 mol/L magnesium sulfate and 1.0 g/L ascorbic acid in leaching agent. In this case, the content of the ion-exchangeable phase and colloidal sediment phase rare earth in the leaching residues are both only 0.02‰. The leaching efficiency of colloid sediment phase rare earth can be 85.7%,so that the Ce partition in the leaching liquor increases to be 5.77%. The magnesium-ascorbic acid compound leaching agent is proposed to be a promising choice to deal with the ion-absorbed rare earths ore, which can realize the efficient leaching, low consumption of MgSO4 and environmentally friendly leaching.

关键词： Rare earth Leaching MgSO4 Ascorbic acid Ion-absorbed rare earths ore

Swelling acidic poly(ionic liquid)s as efficient catalysts for the esterification of cyclohexene and formic acid

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Green Energy & Environment 2020年第2期5卷 138-146页

作者： Xin Wang Sanguan Ma Bihua Chen Jingshun Zhang Yongya Zhang guohua gao Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal University3663 North Zhongshan RoadShanghai200062China

Acidic poly(ionic liquid)s(PILs)with swelling ability were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,divinylbenzene(DVB)and sodium acrylate(NaAA),and further acidification by sulfuric *** swelling ability of acidic PILs was greatly affected by cross-linker content and chain length of 3-alkyl-substituents on ***-linked network structures could be observed from the cryogenic scanning electron microscopy(cryo-SEM)images of the swollen acidic PILs in formic *** PILs with network structures in swollen state exhibited excellent activities in the esterification of cyclohexene and formic acid,and the catalytic activities were in positive correlation with their swelling *** PIL with 3-octyl-substituent and 2.5 mol%DVB(PIL-C8-2.5DVB-HSO4)had the highest swelling ability in formic acid and exhibited comparable catalytic activities with homogeneous catalysts such as sulfuric acid and p-toluenesulfonic acid.

关键词： Acidic poly(ionic liquid)s Swelling Esterification Cyclohexene

Hydrogen peroxide and applications in green hydrocarbon nitridation and oxidation

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Chinese Journal of Chemical Engineering 2022年第1期35卷 145-161页

作者： Yanqiang Shi Yuetong Xia Guangtong Xu Langyou Wen guohua gao Baoning Zong State Key Laboratory of Catalytic Materials and Reaction Engineering Research Institute of Petroleum ProcessingSinopecBeijing 100083China

Basic organic chemicals and high value–added products are mainly produced by hydrocarbon nitridation and ***,several drawbacks limit the application of the traditional oxidation and nitridation technologies in the future,such as complex processes,poor intrinsic safety,low atom utilization,and serious environmental *** green nitridation and oxidation technologies are urgently *** peroxide,a well–known green oxidant,is widely used in green hydrocarbon oxidation and *** its industrial production in China adopts fixed–bed technology,which is fall behind slurry–bed technology adopted by advanced foreign chemical companies,limiting the development of hydrogen peroxide industry and green hydrocarbon nitridation or oxidation *** article reviews the industrial production technologies of hydrogen peroxide and basic organic chemicals such as caprolactam,aniline,propene oxide,epichlorohydrin,phenol,and benzenediol,especially introduces the green production technologies of basic organic chemicals related with H_(2)O_(2).The article also emphasis on the efforts of Chinese researchers in developing its own slurry–bed technology of hydrogen peroxide production,and corresponding green hydrocarbon nitridation or oxidation technologies with hydrogen *** with traditional nitridation or oxidation technologies,green production technologies of caprolactam,propene oxide,epichlorohydrin,and benzenediol with hydrogen peroxide promote the nitrogen atom utilization from 60%to near 100%and the carbon atom utilization from 80%to near 100%.The waste emissions and environmental investments are reduced *** blockade against the green chemical industry of China are partially broken down,and technological upgrade in the chemical industry of China is guaranteed.

关键词： Hydrogen peroxide Green chemical process Partial oxidation Nitridation

Non-ammonia enrichment of rare earth by magnesium oxide from rare earth leaching liquor in magnesium salt system

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Journal of Rare Earths 2019年第8期37卷 886-894,I0004页

作者： Li Huang guohua gao Ran Wu Qian Zhang Fuguo Lai Yanfei Xiao School of Metallurgical and Chemical Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Institute of Engineering&Research Jiangxi University of Science and TechnologyGanzhou 341000China

In order to solve the problem of ammonia-nitrogen pollution in the enrichment process of the ionadsorption type rare earth ore,the technology of non-ammonia precipitation with magnesium oxide precipitant was carried *** is determined that the rare earth precipitation efficiency is 99.6%and the purity of rare earth concentrates is only 85.89 wt%under the optimum precipitation *** the contents of MgO,SO3 and Al2O3 in the rare earth concentrates are 5.12 wt%,6.77 wt%and 1.78 wt%,***,the thermo-decomposition process of precipitates was investigated by TGDSC,XRD and *** thermal decomposition process consists of two stages:the dehydration of rare earth hydroxide and alkaline rare earth sulfate within 900℃and the thermal decomposition of RE2O2SO4 at 900-1300℃.Therefore,a high-temperature calcinations method for removing SO3 from precipitates is *** the precipitates are calcined at 1300℃for 2 h,the rare earth concentrates with a purity of 92.03 wt%can be ***,the content of SO3 in the concentrate is only 0.46 wt%.In the MgO precipitation and high-temperature calcinations process,the raw material cost is low and the quality of rare earth concentrates is *** could have great significance for nonammonia enrichment of rare earth from the rare earth leaching liquor,and finally solve the problem of ammonia nitrogen in the extraction process of the ion-adsorption type rare earth ore within magnesium salt system.

关键词： Non-ammonia Enrichment Magnesium oxide Ion-adsorption type rare earth ore

Efficient synthesis of dimethyl carbonate via transesterification of ethylene carbonate catalyzed by swelling poly(ionic liquid)s

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Green Chemical Engineering 2021年第4期2卷 423-430页

作者： Xin Wang Hao Hu Bihua Chen Lulu Dang guohua gao Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal University3663 North Zhongshan RoadShanghai200062China

The synthesis of dimethyl carbonate(DMC)via transesterification of ethylene carbonate(EC)and methanol(MeOH)was an environmental and practical ***,poly(ionic liquid)s(PILs)with swelling abilities were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,sodium 4-vinylbenzoate and cross-linker(1,8-triethylene glycoldiyl-3,3'-divinylimidazolium bromide([(EG)_(3)-DVIm]Br_(2)).The swelling abilities of PILs in various solvents were measured,and PILs could swell in methanol(MeOH).The swelling ability of PILs in MeOH could be modulated by changing the cross-linker content and chain length of 3-alkyl-substituents on *** swollen state of PILs in MeOH presented a porous cross-linked network structure observed by the cryo-scanning electron microscope(cryo-SEM).The swelling PILs were used to catalyze the transesterification of ethylene carbonate(EC)and MeOH to prepare the DMC,and the catalytic activities was correlated with the swelling abilities of *** PIL with 3-butyl-substituent and 2.5 mol%cross-linker(poly[VBIm-VBA-DVIm]-2.5%)had the highest swelling ratio(Q=12.4(g/g))in MeOH and EC mixed solvents and exhibited excellent catalytic activities,which was similar to corresponding homogeneous ionic ***,the catalyst could be reused up to seven runs without any considerable loss of its initial activity.

关键词： Poly(ionic liquid)s Swelling Transesterification Dimethyl carbonate Methanol

Synthesis of Bis-benzimidazolium Cyclic Receptors and Their Anion Binding Properties

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Chinese Journal of Chemistry 2013年第5期31卷 673-678页

作者： Xiaozhi Jiang Meiyun Feng Dawei Zhang Binshen Wang Zhiyun Dong guohua gao Shanghai Key Laboratory of Green Chemistry and Chemical Processes Department of Chemistry East China Normal University 3663 North Zhongshan Road Shanghai 200062 China

A series of cyclic receptors 1--5 based on bis-benzimidazolium group were designed and synthesized. Their anion recognition properties were investigated by UV-vis, fluorescent spectroscopy, 1H NMR and MALDI-TOF mass spectrometry. The UV-vis and fluorescent spectroscopic studies showed that the receptors 1--5 had different binding abilities for various anions such as fluoride, chloride, bromide, iodide and acetate. The high selectivity of the receptors for fluoride and acetate anions is attributed to their basicity. Job plot and MALDI-TOF mass spec- trometry demonstrated that the receptors form 1 ： 1 complex with fluoride. DFT calculation and 1H NMR studies indicated that the receptors bind anions through （C--H）＋…X- hydrogen bond.

关键词： cyclic ionic receptors bis-benzimidazolium anion recognition hydrogen bond

Ionic liquids containing the urea moiety for recognition of halides and complex anions

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Chinese Science Bulletin 2012年第5期57卷 473-478页

作者： DONG ZhiYun YANG Yu ZHANG LiFeng XUE YunRong FENG MeiYun gao guohua Shanghai Key Laboratory of Green Chemistry and Chemical Processes Department of ChemistryEast China Normal UniversityShanghai200062China

A series of novel imidazolium based ionic liquids containing the urea moiety were designed and synthesized for anion recognition. 1-Ethylurea-3-methylimidazolium acetate ([Eumim]OAc) was used as the receptor for the halides and complex anions (BF4-, PF6-, BPh4-). 1H NMR spectra showed that the urea protons and imidazolium C(2) proton of the receptor ([Eumim]OAc) moved upfield on addition of various anions. A Job plot showed that the [Eumim]OAc receptor formed a 1:1 complex with BPh4-. X-ray diffraction analysis and the molecular modeling study revealed that the conformations of [Eumim]OAc and [Eumim]BPh4 were different. The conformational change of the cation was caused by anion exchange, and may provide an alternative to current methods for recognition of anions.

关键词：阴离子识别离子液体卤化物尿素成分 X射线衍射分析质子受体构象变化

Compliance Modeling of a Compliant Stage with Symmetric Configuration

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Journal of Applied Mathematics and Physics 2020年第11期8卷 2500-2508页

作者： Yunsong Du guohua gao Faculty of Materials and Manufacturing Beijing University of Technology Beijing China College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology Beijing China

This paper presents the compliance modeling of a compliant stage with symmetric configuration. Empirical compliance equations for the circular flexure hinge are first introduced. Using the matrix method, the output compliance of a compliant stage with symmetric configuration is then obtained. Finally, the compliances derived from the proposed theoretical model and finite element analysis (FEA) are compared. It indicates that the results calculated by the theoretical model are in good agreement with those derived from FEA, which demonstrates the accuracy of the theoretical model.

关键词： Flexure Hinge Compliance Modeling Compliant Stage Symmetric Configuration

A Method of Eliminating Information Disclosure in View Publishing

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Wuhan University Journal of Natural Sciences 2006年第6期11卷 1753-1756页

作者： LIU guohua gao Shihong College of Information Science and Engineering Yanshan University Qinhuangdao 066004 Hebei China

Although it is convenient to exchange data by publishing view, but it may disclose sensitive information. The problem of how to eliminate information disclosure becomes a core problem in the view publishing process. In order to eliminate information disclosure, deciding view security algorithm and eliminating information disclosure algorithm are proposed, and the validity of the algorithms are proved by experiment. The experimental results showing, deciding view security algorithm can decide the safety of a set of views under prior knowledge, and eliminating information disclosure algorithm can eliminate disclosure efficiently.

关键词： view publishing sensitive information prior knowledge information disclosure