Patents by Inventor Xue Duan

Xue Duan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11524901
    Abstract: This invention provides a method for efficiently separating magnesium and lithium from salt lake brine, and simultaneously preparing high-purity magnesium oxide and battery-grade lithium carbonate. The detailed processing steps are as follows: (1) adding urea into the brine to dissolve, (2) placing the solution into the reactor for hydrothermal reaction, the magnesium ion will precipitate and enter the solid phase; (3) filtering and drying the production to get the magnesium carbonate solid, while the lithium ion remains in the liquid phase; (4) after directly concentration and precipitation, the battery-grade lithium carbonate can be obtained, while the calcination of solid-phase product results in the high-purity magnesium oxide. In this method, urea is used as the precipitant to separate magnesium and lithium in salt lake without introducing any new metal ion, and the brine solution is not diluted. The solid product is white and fluffy powder, which is easy to filter and separate.
    Type: Grant
    Filed: March 8, 2019
    Date of Patent: December 13, 2022
    Assignee: BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY
    Inventors: Xu Xiang, Xue Duan
  • Patent number: 11414324
    Abstract: Described is a method for extracting lithium from salt lake brine and simultaneously preparing aluminum hydroxide. This method includes a. adding an aluminum salt to the brine, adding an alkali solution, then subjecting to crystallization reaction and solid-liquid separation to obtain lithium-containing brine; b. evaporating and concentrating the lithium-containing brine, adding an aluminum salt, adding an alkali solution dropwise to perform a co-precipitation reaction and solid-liquid separation to obtain a lithium-containing layered material filter cake, wherein in steps a and b, the alkali solution is an alkali solution free of carbonate ion; c. dispersing the lithium-containing layered material filter cake in deionized water to form a suspension slurry, then adjusting the pH value of the suspension slurry so as to carry out a lithium deintercalation reaction; d. filtering to obtain aluminum hydroxide filter cake; e. washing the aluminum hydroxide filter cake with deionized water and drying.
    Type: Grant
    Filed: April 19, 2019
    Date of Patent: August 16, 2022
    Assignee: BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY
    Inventors: Xu Xiang, Xue Duan
  • Publication number: 20210221697
    Abstract: The present disclosure relates to a method for extracting lithium from salt lake brine and simultaneously preparing aluminum hydroxide. This method includes: a. adding an aluminum salt to the brine to obtain a mixed salt solution A, adding an alkali solution to the mixed salt solution A for co-precipitation reaction, then subjecting to crystallization reaction and solid-liquid separation at the end of the reaction to obtain magnesium-aluminum hydrotalcite solid product and lithium-containing brine, wherein in step a, the alkali solution is an alkali solution free of carbonate ion; b.
    Type: Application
    Filed: April 19, 2019
    Publication date: July 22, 2021
    Inventors: Xu XIANG, Xue DUAN
  • Publication number: 20210139340
    Abstract: This invention provides a method for efficiently separating magnesium and lithium from salt lake brine, and simultaneously preparing high-purity magnesium oxide and battery-grade lithium carbonate. The detailed processing steps are as follows: (1) adding urea into the brine to dissolve, (2) placing the solution into the reactor for hydrothermal reaction, the magnesium ion will precipitate and enter the solid phase; (3) filtering and drying the production to get the magnesium carbonate solid, while the lithium ion remains in the liquid phase; (4) after directly concentration and precipitation, the battery-grade lithium carbonate can be obtained, while the calcination of solid-phase product results in the high-purity magnesium oxide. In this method, urea is used as the precipitant to separate magnesium and lithium in salt lake without introducing any new metal ion, and the brine solution is not diluted. The solid product is white and fluffy powder, which is easy to filter and separate.
    Type: Application
    Filed: March 8, 2019
    Publication date: May 13, 2021
    Inventors: Xu XIANG, Xue DUAN
  • Patent number: 10016727
    Abstract: The present invention relates to a method for extracting magnesium and lithium and also producing layered double hydroxides (LDH) from brine, comprising the steps of: adding an aluminum salt to brine, to prepare a mixed salt solution A for preparing MgAl-LDH; adding an alkaline solution to carry out co-precipitation, followed by crystallization; after the crystallization is complete, performing solid-liquid separation to obtain a solid product of MgAl-LDH and a filtrate; concentrating the filtrate by evaporation to obtain a lithium-rich brine, adding an aluminum salt thereto to prepare a mixed salt solution B for preparing LiAl-LDH; adding the mixed salt solution B to an alkaline solution to carry out precipitation; after the precipitation is complete, performing solid-liquid separation to obtain a solid product of LiAl-LDH and a filtrate; and concentrating the filtrate by evaporation, returning the solution concentrated by evaporation to the lithium-rich brine for recycled use.
    Type: Grant
    Filed: November 13, 2015
    Date of Patent: July 10, 2018
    Assignee: Beijing University of Chemical Technology
    Inventors: Xu Xiang, Ruirui Wang, Xue Duan
  • Publication number: 20170189855
    Abstract: The present invention relates to a method for extracting magnesium and lithium and also producing layered double hydroxides (LDH) from brine, comprising the steps of: adding an aluminum salt to brine, to prepare a mixed salt solution A for preparing MgAl-LDH; adding an alkaline solution to carry out co-precipitation, followed by crystallization; after the crystallization is complete, performing solid-liquid separation to obtain a solid product of MgAl-LDH and a filtrate; concentrating the filtrate by evaporation to obtain a lithium-rich brine, adding an aluminum salt thereto to prepare a mixed salt solution B for preparing LiAl-LDH; adding the mixed salt solution B to an alkaline solution to carry out precipitation; after the precipitation is complete, performing solid-liquid separation to obtain a solid product of LiAl-LDH and a filtrate; and concentrating the filtrate by evaporation, returning the solution concentrated by evaporation to the lithium-rich brine for recycled use.
    Type: Application
    Filed: November 13, 2015
    Publication date: July 6, 2017
    Inventors: Xu Xiang, Ruirui Wang, Xue Duan
  • Patent number: 9475705
    Abstract: The present invention belongs to the synthesis technology field of inorganic functional materials, and particularly provides a self-balanced high-pressure and high-shear autoclave and its application in the preparation of layered double hydroxides (LDHs). In this invention, by imbedding the handpiece of emulsification mill into the autoclave, and by taking the motor driving system outside of the autoclave, the pressure of the autoclave can be highly stable by the use of self-balanced seal gland. These characters solve the problem that the typical emulsification mill cannot be used in high-pressure system, and ensure the crystallization under the high-pressure and high-shear conditions. Such autoclave takes the advantages of additional equipment, and eliminates the volume effect in the amplification process. By the use of this new autoclave, the reaction time can be shorten from 24 hours to 2-6 hours, the reaction temperature can be reduced from 180° C. to 140° C.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: October 25, 2016
    Assignees: BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY, JIANGYIN RUIFA CHEMICAL CO., LTD.
    Inventors: Yanjun Lin, Kaitao Li, Bo Ning, Dianqing Li, Xue Duan, Chenfa Wen, Xuchang Tan
  • Patent number: 9315420
    Abstract: The present invention relates to a preparation method for a UV-shielding material based on Mg—Al Layered Double Hydroxide. The material with multi-layered overlay structure is made from Mg—Al double hydroxide layers and interlayer carbonate, its molecular composition is: Mg1-xAlx(OH)2(CO3)x/2.mH2O. The inorganic layers of this material can play a physical shielding role against UV, and the metal elements dispersed on the layer as well as the interlayer anion can play a great role in the chemical absorbing. In addition, by controlling the particle size and the amount of the layers, UV light can be effectively shielded by multi-level reflection and absorption of the multi-level layered structure. Therefore, the material with multi-level chemical and physical shielding properties has a good UV barrier effect for the anti-ageing asphalt, and could significantly increase its UV resistance properties.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: April 19, 2016
    Assignees: BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY, WUHAN UNIVERSTIY OF TECHNOLOGY
    Inventors: Xue Duan, Wenying Shi, Min Wei, Yanjun Lin, Shaopeng Wu, Jianying Yu
  • Publication number: 20160009566
    Abstract: The present invention belongs to the synthesis technology field of inorganic functional materials, and particularly provides a self-balanced high-pressure and high-shear autoclave and its application in the preparation of layered double hydroxides (LDHs). In this invention, by imbedding the handpiece of emulsification mill into the autoclave, and by taking the motor driving system outside of the autoclave, the pressure of the autoclave can be highly stable by the use of self-balanced seal gland. These characters solve the problem that the typical emulsification mill cannot be used in high-pressure system, and ensure the crystallization under the high-pressure and high-shear conditions. Such autoclave takes the advantages of additional equipment, and eliminates the volume effect in the amplification process. By the use of this new autoclave, the reaction time can be shorten from 24 hours to 2-6 hours, the reaction temperature can be reduced from 180° C. to 140° C.
    Type: Application
    Filed: May 21, 2013
    Publication date: January 14, 2016
    Inventors: Yanjun LIN, Kaitao LI, Bo NING, Dianqing LI, Xue DUAN, Chenfa WEN, Xuchang TAN
  • Patent number: 9029167
    Abstract: This invention relates to the field of preparation technology of optical pH sensor by co-intercalated fluorescein and 1-heptanesulfonic acid sodium into layered double hydroxide. The sensor is composed by conductive materials and the surface LDH films by co-interacted FLU and HES. The synthesis method is: first: synthesis of LDH colloid suspension, subsequently, the FLU and HES co-intercalated LDH colloid solution was prepared following the ion-exchange method, then the thin film of FLU-HES/LDH was spreaded on the surface of the conductive material by electrophoretic deposition, and the oriental pH sensor was synthesized. The advantages of the present invention is: first, the LDH matrix provides chromophore molecules with a confined and stable environment; the novel electrophoretic deposition strategy in this work provides a method for precise control of thickness (ranging from nanometers to micrometers), and the oriental pH sensor show good pH responsive.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: May 12, 2015
    Assignee: Beijing University of Chemical Technology
    Inventors: Min Wei, Wenying Shi, Jun Lu, Xue Duan
  • Patent number: 8906337
    Abstract: The present invention relates to a method for preparing graphene using the two-dimensional confined space between the layers of inorganic layered materials. Such method comprises the following steps: mix a soluble salt of a divalent metal ion M2+, a soluble salt of a trivalent metal ion M?3+, a soluble salt of a chain alkyl anion A? and a carbon source molecule C and dissolve them in deionized and CO2-eliminated water to prepare a mixed salt solution; mix the mixed salt solution with an alkali solution under nitrogen protection and subject them to reaction and crystallization under nitrogen, and filter the suspension obtained thereafter and wash the filter cake with deionized water until the pH of the filtrate is 7 to 7.
    Type: Grant
    Filed: March 27, 2012
    Date of Patent: December 9, 2014
    Assignee: Beijing University of Chemical Technology
    Inventors: Wensheng Yang, Jie Sun, Haimei Liu, Xu Chen, Xue Duan
  • Patent number: 8765632
    Abstract: A process for preparing a catalyst comprising palladium supported on a carrier via a layered precursor, comprising the following steps: (1) synthesis of hydrotalcite layered precursor which comprises promoting metal element and aluminium on the surface of the carrier of A12O3 microspheres, the atoms of the promoting metal and aluminium being highly dispersed by each other and bonded firmly to the carrier due to the crystal lattice positioning effect of the hydrotalcite crystal; (2) introduction of palladium into the carrier through impregnation; (3) drying; and (4) calcination and reduction with H2, the hydrotalcite layered precursor being converted into a composite oxide which consists of oxides of the promoting metal and aluminium, and the promoting metal element and aluminium being highly dispersed by each other and being able to separate and disperse the mainly active palladium element loaded later.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: July 1, 2014
    Assignee: Beijing University of Chemical Technology
    Inventors: Fazhi Zhang, Peng Chen, Rong Hou, Jiali Chen, Chao Gao, Hui Zhang, Dianqing Li, Feng Li, Xue Duan
  • Publication number: 20140154165
    Abstract: The present invention relates to a method for preparing graphene using the two-dimensional confined space between the layers of inorganic layered materials. Such method comprises the following steps: mix a soluble salt of a divalent metal ion M2+, a soluble salt of a trivalent metal ion M?3+, a soluble salt of a chain alkyl anion A? and a carbon source molecule C and dissolve them in deionized and CO2-eliminated water to prepare a mixed salt solution; mix the mixed salt solution with an alkali solution under nitrogen protection and subject them to reaction and crystallization under nitrogen, and filter the suspension obtained thereafter and wash the filter cake with deionized water until the pH of the filtrate is 7 to 7.
    Type: Application
    Filed: March 27, 2012
    Publication date: June 5, 2014
    Applicant: BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY
    Inventors: Wensheng Yang, Jie Sun, Haimei Liu, Xu Chen, Xue Duan
  • Patent number: 8318123
    Abstract: The present invention discloses a preparation method of carbon nanotube by decomposing the polymer with hydrotalcite as a catalyst, which belongs to the field of preparation technology of carbon nanotube (CNT). The technical solution of the present invention are as below: firstly, the hydrotalcite with the particle size at nanometer or sub-micron level is prepared, and then is added into the polymer. After the calcination process at high temperature and a treatment with acid, the nano-scale CNT can be obtained. The CNTs prepared by the method supplied in this invention not only have the advantages including high yield, uniform diameter, few structural defects, low impurity content, low cost and simple preparation process, which is suitable for large-scale industrial production, but also can solve the problem of recirculation of waste plastics and utilization of the resource.
    Type: Grant
    Filed: January 12, 2010
    Date of Patent: November 27, 2012
    Assignee: Beijing University of Chemical Technology
    Inventors: Fazhi Zhang, Lixia Zhang, Xiaodong Lei, Rushi Li, Sailong Xu, Xue Duan
  • Patent number: 8309741
    Abstract: The present invention discloses a benzocarbazole-intercalated layered double hydroxides (LDHs) composite luminescent material and its preparation method. The detailed procedure comprises preparing divalent and trivalent metal cation solution A and glycol solution B of sodium 2-hydroxy benzo[a]carbazole-3-carboxylate, mixing the solutions A and B to obtain solution C, slowly adding the prepared NaOH solution dropwise into the solution C, regulating pH of the resultant after dropwise addition to obtain slurry D, allowing the slurry D to react under water bath or microwave temperature-controlled heating condition, centrifuging and washing the obtained product, and drying in vacuum to obtain 2-hydroxy benzo[a]carbazole-3-carboxylate anion intercalated LDHs composite material.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: November 13, 2012
    Assignee: Beijing University of Chemical Technology
    Inventors: Dongpeng Yan, Jun Lu, Min Wei, Xue Duan
  • Publication number: 20120282706
    Abstract: This invention relates to the field of preparation technology of optical pH sensor by co-intercalated fluorescein and 1-heptanesulfonic acid sodium into layered double hydroxide. The sensor is composed by conductive materials and the surface LDH films by co-interacted FLU and HES. The synthesis method is: first: synthesis of LDH colloid suspension, subsequently, the FLU and HES co-intercalated LDH colloid solution was prepared following the ion-exchange method, then the thin film of FLU-HES/LDH was spreaded on the surface of the conductive material by electrophoretic deposition, and the oriental pH sensor was synthesized. The advantages of the present invention is: first, the LDH matrix provides chromophore molecules with a confined and stable environment; the novel electrophoretic deposition strategy in this work provides a method for precise control of thickness (ranging from nanometers to micrometers), and the oriental pH sensor show good pH responsive.
    Type: Application
    Filed: March 12, 2010
    Publication date: November 8, 2012
    Applicant: Beijing University of Chemical Technology
    Inventors: Min Wei, Wenying Shi, Jun Lu, Xue Duan
  • Patent number: 8298618
    Abstract: A preparation method of composite blue luminescent thin film of sulfonated poly(p-phenylene) (i.e. poly[2,5-bis(3-sulfonatopropoxy)-1,4-phenylene-alt-1,4-phenylene]) and LDHs (Layered Double Hydroxides) is disclosed. The preparation method comprises the following steps: preparing delaminated LDHs colloidal solution using formamide solvent, preparing sulfonated poly(p-phenylene) aqueous solution, and performing alternate assembling on hydrophilically treated substrate in the two solutions to give the composite thin film of sulfonated poly(p-phenylene)/LDHs multilayer. The preparation method has the advantages of simple preparation process, and film thickness controllable at nanoscale precision, in addition, this method also achieves the immobilization of luminescent polymer via restricted space among LDHs layers and host-guest interaction, effectively improves thermal stability, and reduces fluorescence quenching caused by aggregation.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: October 30, 2012
    Assignee: Beijing University of Chemical Technology
    Inventors: Dongpeng Yan, Jun Lu, Min Wei, Xue Duan
  • Publication number: 20120240821
    Abstract: The present invention relates to a preparation method for a UV-shielding material based on Mg—Al Layered Double Hydroxide. The material with multi-layered overlay structure is made from Mg—Al double hydroxide layers and interlayer carbonate, its molecular composition is: Mg1-xAlx(OH)2(CO3)x/2.mH2O. The inorganic layers of this material can play a physical shielding role against UV, and the metal elements dispersed on the layer as well as the interlayer anion can play a great role in the chemical absorbing. In addition, by controlling the particle size and the amount of the layers, UV light can be effectively shielded by multi-level reflection and absorption of the multi-level layered structure. Therefore, the material with multi-level chemical and physical shielding properties has a good UV barrier effect for the anti-ageing asphalt, and could significantly increase its UV resistance properties.
    Type: Application
    Filed: February 22, 2012
    Publication date: September 27, 2012
    Applicants: WUHAN UNIVERSITY OF TECHNOLOGY, Beijing University of Chemical Technology
    Inventors: Xue DUAN, Wenying Shi, Min Wei, Yanjun Lin, Shaopeng Wu, Jianying Yu
  • Patent number: 8088349
    Abstract: Disclosed is a clean method for preparing layered double hydroxides (LDHs), in which hydroxides of different metals are used as starting materials for production of LDHs by atom-economical reactions. The atom efficiency of the reaction is 100% in each case because all the atoms of the reactants are converted into the target product since only M2+(OH)2, M3+(OH)3, and CO2 or HnAn? are used, without any NaOH or other materials. Since there is no by-product, filtration or washing process is unnecessary. The consequent reduction in water consumption is also beneficial to the environment.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: January 3, 2012
    Assignee: Beijing University of Chemical Technology
    Inventors: Xue Duan, Dianqing Li, Zhi Lv, Yanjun Lin, Xiangyu Xu
  • Publication number: 20110268646
    Abstract: The present invention discloses a preparation method of carbon nanotube by decomposing the polymer with hydrotalcite as a catalyst, which belongs to the field of preparation technology of carbon nanotube (CNT). The technical solution of the present invention are as below: firstly, the hydrotalcite with the particle size at nanometer or sub-micron level is prepared, and then is added into the polymer. After the calcination process at high temperature and a treatment with acid, the nano-scale CNT can be obtained. The CNTs prepared by the method supplied in this invention not only have the advantages including high yield, uniform diameter, few structural defects, low impurity content, low cost and simple preparation process, which is suitable for large-scale industrial production, but also can solve the problem of recirculation of waste plastics and utilization of the resource.
    Type: Application
    Filed: January 12, 2010
    Publication date: November 3, 2011
    Applicant: BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY
    Inventors: Fazhi Zhang, Lixia Zhang, Xiaodong Lei, Rushi Li, Sailong Xu, Xue Duan