CN113603129B - Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization - Google Patents

Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization Download PDF

Info

Publication number
CN113603129B
CN113603129B CN202111000389.6A CN202111000389A CN113603129B CN 113603129 B CN113603129 B CN 113603129B CN 202111000389 A CN202111000389 A CN 202111000389A CN 113603129 B CN113603129 B CN 113603129B
Authority
CN
China
Prior art keywords
rare earth
aluminate
pressure digestion
raw material
polytetrafluoroethylene
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202111000389.6A
Other languages
Chinese (zh)
Other versions
CN113603129A (en
Inventor
王金淑
蔡永丰
胡鹏
宋宁宁
杨韵斐
周文元
周帆
刘乐奇
刘赫雄
张强
胡志凯
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing University of Technology
Original Assignee
Beijing University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing University of Technology filed Critical Beijing University of Technology
Priority to CN202111000389.6A priority Critical patent/CN113603129B/en
Publication of CN113603129A publication Critical patent/CN113603129A/en
Application granted granted Critical
Publication of CN113603129B publication Critical patent/CN113603129B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01FCOMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F17/00Compounds of rare earth metals
    • C01F17/30Compounds containing rare earth metals and at least one element other than a rare earth metal, oxygen or hydrogen, e.g. La4S3Br6
    • C01F17/32Compounds containing rare earth metals and at least one element other than a rare earth metal, oxygen or hydrogen, e.g. La4S3Br6 oxide or hydroxide being the only anion, e.g. NaCeO2 or MgxCayEuO
    • C01F17/34Aluminates, e.g. YAlO3 or Y3-xGdxAl5O12
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01FCOMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F17/00Compounds of rare earth metals
    • C01F17/10Preparation or treatment, e.g. separation or purification
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00Crystal-structural characteristics
    • C01P2002/80Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/01Particle morphology depicted by an image
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/01Particle morphology depicted by an image
    • C01P2004/02Particle morphology depicted by an image obtained by optical microscopy

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Analytical Chemistry (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Luminescent Compositions (AREA)

Abstract

A new approach for synthesizing rare earth-containing aluminate with photoelectric function based on high mechanization belongs to the field of preparation of inorganic photoelectric functional materials. The method is based on three steps of high-pressure digestion, freeze drying and high-temperature calcination, and comprises the steps of weighing raw materials of an aluminum source, a rare earth oxide and other raw materials in proportion, mixing with a proper amount of deionized water, and adding into a polytetrafluoroethylene lining of a high-pressure digestion tank. After high-pressure digestion and freeze drying, the superfine rare-earth-containing aluminate precursor with good uniformity can be directly obtained without post-treatment. Then, the rare earth-containing photoelectric functional aluminate used in the field of electron emission and the field of light functional materials can be obtained through a tubular furnace high-temperature calcination process. The process has high degree of mechanization, all the engineering quantities are completed by equipment, and the quality control of products is strengthened to the greatest extent. Meanwhile, the high-pressure digestion process enables the raw materials with high density difference to be fully and uniformly mixed, and the phenomena of slightly soluble material flow in the traditional washing process and uneven distribution of hot drying precursors are eliminated.

Description

Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization
Technical Field
The invention relates to a high-mechanization preparation method of rare earth-containing aluminate with photoelectric function, belonging to the technical field of preparation of inorganic photoelectric functional materials.
Background
The rare-earth-containing aluminate with high added value is widely applied to the fields of electron emission and optical functional materials, and the interchange between optical functional aluminate and electrical functional aluminate can be realized by adjusting components and preparation process, so that the preparation methods of the two materials have great similarity. At present, the application of rare-earth aluminate in electron emission materials mainly refers to scandium-containing aluminate and scandium-containing yttrium aluminate used in scandium-containing cathodes, and the light-function rare-earth aluminate-containing materials are mainly applied to aspects of LED devices, afterglow luminescence, biological imaging, display and development and the like. The wide application leads the preparation method of the aluminate containing the rare earth photoelectric function to be comprehensively developed.
The method most commonly used in the industry at present is a high-temperature solid phase method, the method has the greatest advantages of rapidness and low price, but the component uniformity of the precursor and the product repeatability cannot be ensured frequently, and the method is a problem which needs to be solved for the rare-earth-containing aluminate with high added value. Therefore, sol-gel method, hydrothermal method, combustion method, precipitation method and other preparation methods have appeared. However, besides hydrothermal method, other methods have complicated steps or harsh reaction conditions, and are difficult to be applied in industrial process, and thus, the method has not been applied well in practical production. In the hydrothermal method, water is used as a solvent and a mineralizer, is a medium for transferring pressure, and can promote the dissolution-reprecipitation process of the rare-earth aluminate-containing raw material under certain pressure, thereby improving the morphology, granularity and aggregation form of the precursor.
The invention is different from the traditional hydrothermal/digestion method, provides a high-mechanization preparation method of aluminate containing rare earth photoelectric function based on high-pressure digestion, and the aluminate containing rare earth photoelectric function is obtained by three steps of high-pressure digestion, freeze drying and high-temperature calcination. Compared with other preparation methods containing rare earth aluminate, the process has high degree of mechanization, all the engineering quantities are completed by equipment, and the quality control of the product is enhanced to the greatest extent. Has very great application prospect in the industrial production of rare-earth aluminate with high added value.
Disclosure of Invention
The invention provides a highly mechanized preparation method of rare earth-containing aluminate with photoelectric function, which is realized by the following steps:
step A: weighing an aluminum source, a rare earth oxide and carbonate or hydroxide of alkaline earth metal as raw materials in proportion, mixing the raw materials with deionized water, adding the mixture into a polytetrafluoroethylene lining, and then putting the polytetrafluoroethylene lining into a high-pressure digestion tank;
and B, step B: heating the high-pressure digestion tank for 24 hours at 180-200 ℃ by using a blast oven or a homogeneous reactor, naturally cooling and taking out after the heat preservation is finished, and transferring the high-pressure digestion tank into a polytetrafluoroethylene beaker;
step C: freezing the liquid phase raw material mixture subjected to high-pressure digestion and a polytetrafluoroethylene beaker together by using liquid nitrogen, putting the frozen solid phase raw material mixture into a freeze dryer which is cooled to the temperature of between 70 ℃ below zero and 80 ℃ below zero in advance to perform a low-temperature vacuum drying process for more than 12 hours, and taking out the solid phase raw material mixture after complete drying to obtain a powder raw material mixture containing the rare earth photoelectric function aluminate without further treatment;
step D: the powder raw material mixture containing the rare earth photoelectric function aluminate is put into a vertical high-temperature tubular furnace under nitrogen atmosphere (99.99 percent) to be sintered to 1400-1600 ℃, and is kept warm for 1-10 hours, and is taken out and ground after being cooled, so that the rare earth photoelectric function aluminate is obtained.
In step a of the above invention, the aluminum source is selected from aluminum hydroxide, aluminum oxide, aluminum nitrate, etc.; the proportions of the raw materials follow the following principles. Al in aluminum source 2 O 3 The content of (A) is 15-25mol% of the whole raw material; the content of rare earth oxide is 1-20mol% of the whole raw material, and the rest is carbonate or hydroxide of alkaline earth metal.
In step A of the above invention, the pressure of the high-pressure digestion tank (as shown in FIG. 2) during the reaction is 6MPa, not usually 3MPa.
In the step B of the present invention, when the high-pressure digestion reaction is carried out using the forced air drying oven, the stirring at room temperature needs to be carried out for 24 hours in advance. If a homogeneous reactor is used, the high-pressure digestion reaction is directly carried out without a stirring process.
In the step B of the invention, the lining of the high-pressure digestion tank and the beaker are made of polytetrafluoroethylene products (as shown in fig. 2) produced under the same quality standard, so as to eliminate the influence of impurities in external equipment on the experiment to the maximum extent.
In the step C of the invention, because the polytetrafluoroethylene has poor thermal conductivity and the rare earth oxide and other raw materials have high density difference, the freezing step adopts the process of the combined action of contact freezing and non-contact freezing of the raw material mixture and liquid nitrogen, namely, the liquid nitrogen is arranged inside and outside the polytetrafluoroethylene beaker, the liquid nitrogen in the polytetrafluoroethylene beaker is directly contacted and frozen with the liquid-phase raw material mixture after high-pressure digestion, and simultaneously, the liquid nitrogen outside the polytetrafluoroethylene beaker is non-contacted and frozen with the liquid-phase raw material mixture after high-pressure digestion.
The invention synthesizes the aluminate containing the rare earth photoelectric function by using a new high-mechanization way, and the prepared precursor containing the rare earth aluminate has uniform components, uniform distribution of rare earth oxide (as shown in figure 3) and no obvious agglomeration phenomenon.
As shown in FIG. 4, the Sc-W cathode composed of the rare earth aluminate-containing material prepared in example 1 has a good electron emission ability. As shown in fig. 5, the rare earth-containing luminescent materials prepared in examples 2 and 3 have good optical properties under ultraviolet excitation, wherein example 2 is orange yellow, and example 3 is orange red. A plurality of embodiments show that the new way of the invention can prepare the aluminate containing the rare earth photoelectric function with good performance, has high mechanization degree, and is suitable for large-scale, batch and industrial production.
Drawings
FIG. 1 is a flow chart of an experiment related to the present invention
FIG. 2 is a high pressure digestion tank shell, polytetrafluoroethylene inner liner and polytetrafluoroethylene beaker used in the present invention.
FIG. 3 is a SEM photograph and elemental distribution of samples of example 2
Fig. 4 is a graph showing the electron emission of a scandium-tungsten cathode composed of rare earth aluminate prepared in example 1.
FIG. 5 is color images of rare earth-containing optical materials prepared in examples 2 and 3 under different light sources.
The specific implementation mode is as follows:
the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.
The pressure of the high-pressure digestion tank (shown in FIG. 2) during the reaction was 6MPa.
Example 1
Weighing 0.4681g of aluminum hydroxide, 0.5172g of scandium oxide, 3.7858g of barium hydroxide octahydrate and 0.2223g of calcium hydroxide by using an analytical balance, mixing the above materials with a proper amount of deionized water, stirring for 24 hours, adding the mixture into a polytetrafluoroethylene lining, and then putting the polytetrafluoroethylene lining into a high-pressure digestion tank. And (3) heating the high-pressure digestion tank for 24 hours at 200 ℃ by using a blast oven, naturally cooling and taking out after the heat preservation is finished, and transferring the high-pressure digestion tank into a polytetrafluoroethylene beaker. Freezing the liquid phase raw material mixture subjected to high-pressure digestion and a polytetrafluoroethylene beaker together by using liquid nitrogen, and putting the frozen solid phase raw material mixture into a freeze dryer which is cooled to-76 ℃ in advance to perform a low-temperature vacuum drying process for 13 hours. After the mixture is completely dried, the mixture is taken out and can be obtained without further treatment. And (3) putting the powder raw material mixture into a vertical high-temperature tube furnace in a nitrogen atmosphere (99.99%) to be sintered to 1500 ℃, preserving the heat for 1 hour, cooling, taking out and grinding to obtain the aluminate containing the rare earth photoelectric function.
Example 2
Weighing 5363 g of aluminum hydroxide, 0.7802g of europium oxide, 0.0176g of barium hydroxide octahydrate, 4.7322g of calcium hydroxide and 0.1852g of calcium hydroxide by using an analytical balance, mixing the above substances with a proper amount of deionized water, stirring for 24 hours, adding the mixture into a polytetrafluoroethylene lining, and then putting the polytetrafluoroethylene lining into a high-pressure digestion tank. And (3) heating the high-pressure digestion tank for 24 hours at 200 ℃ by using a blast oven, taking out after the heat preservation is finished and naturally cooling, and transferring the high-pressure digestion tank to a polytetrafluoroethylene beaker. And (3) freezing the liquid phase raw material mixture subjected to high-pressure digestion and a polytetrafluoroethylene beaker together by using liquid nitrogen, and putting the frozen solid phase raw material mixture into a freeze dryer which is cooled to-73 ℃ in advance to perform a low-temperature vacuum drying process for 12.5 hours. After the mixture is completely dried, the mixture is taken out and can be obtained without further treatment. And putting the powder raw material mixture into a vertical high-temperature tubular furnace in a nitrogen atmosphere (99.99 percent), sintering to 1500 ℃, preserving the heat for 10 hours, cooling, taking out and grinding to obtain the rare earth-containing photoelectric functional aluminate.
Example 3
0.5098g of alumina, 0.8619g of scandia, 0.0704g of europium oxide, 3.9468g of barium carbonate and 0.5004g of calcium carbonate are weighed by using an analytical balance, mixed with a proper amount of deionized water and then added into a polytetrafluoroethylene lining, and then the polytetrafluoroethylene lining is placed into a high-pressure digestion tank. And (3) keeping the temperature of the high-pressure digestion tank at 180 ℃ for 24 hours by using a blast oven, taking out the high-pressure digestion tank after the heat preservation is finished, naturally cooling the high-pressure digestion tank, and transferring the high-pressure digestion tank to a polytetrafluoroethylene beaker. Freezing the liquid phase raw material mixture subjected to high pressure digestion and a polytetrafluoroethylene beaker together by using liquid nitrogen, and putting the frozen solid phase raw material mixture into a freeze dryer which is cooled to-78 ℃ in advance to perform a low-temperature vacuum drying process for 15 hours. After the mixture is completely dried, the mixture is taken out and can be obtained without further treatment. And putting the powder raw material mixture into a vertical high-temperature tubular furnace in a nitrogen atmosphere (99.99 percent), sintering to 1500 ℃, preserving the heat for 10 hours, cooling, taking out and grinding to obtain the rare earth-containing photoelectric functional aluminate.

Claims (5)

1. The high-mechanization preparation method of the aluminate with the rare earth photoelectric function is characterized by comprising the following steps:
step A: weighing an aluminum source, a rare earth oxide and carbonate or hydroxide of alkaline earth metal as raw materials in proportion, mixing the raw materials with deionized water, adding the mixture into a polytetrafluoroethylene lining, and then putting the polytetrafluoroethylene lining into a high-pressure digestion tank;
and B: heating the high-pressure digestion tank for 24 hours at 180-200 ℃ by using a blast oven or a homogeneous reactor, naturally cooling and taking out after the heat preservation is finished, and transferring the high-pressure digestion tank into a polytetrafluoroethylene beaker;
and C: freezing the liquid phase raw material mixture subjected to high-pressure digestion and a polytetrafluoroethylene beaker together by using liquid nitrogen, putting the frozen solid phase raw material mixture into a freeze dryer which is cooled to the temperature of between 70 ℃ below zero and 80 ℃ below zero in advance to perform a low-temperature vacuum drying process for more than 12 hours, and taking out the solid phase raw material mixture after complete drying to obtain a powder raw material mixture containing the rare earth photoelectric function aluminate without further treatment;
step D: putting the powder raw material mixture containing the rare earth photoelectric function aluminate into a vertical high-temperature tubular furnace in the atmosphere of 99.99 percent nitrogen, sintering to 1400-1600 ℃, preserving heat for 1-10 hours, cooling, taking out and grinding to obtain the rare earth photoelectric function aluminate;
in the step A, an aluminum source is selected from aluminum hydroxide, aluminum oxide and aluminum nitrate; the proportion of the raw materials follows the following principle; al in aluminum source 2 O 3 The content of (A) is 15-25mol% of the whole raw material; the content of rare earth oxide is 1-20mol% of the whole raw material, and the rest is carbonate or hydroxide of alkaline earth metal.
2. The highly mechanized preparation method of rare earth-containing aluminate with photoelectric function according to claim 1, wherein in step A, the pressure of the high-pressure digestion tank is 6MPa during the reaction.
3. The highly mechanized preparation method of aluminate with rare earth photoelectric function according to claim 1, wherein in the step B, if the high pressure digestion reaction is carried out by using an air-blast drying oven, the normal temperature stirring is carried out for 24 hours in advance; if a homogeneous reactor is used, the high-pressure digestion reaction is directly carried out without a stirring process.
4. The method for preparing the rare earth-containing photoelectric functional aluminate in a highly mechanized manner according to claim 1, wherein in the step B, the lining of the high-pressure digestion tank and the beaker are made of polytetrafluoroethylene products which are produced under the same quality standard, so as to eliminate the influence of impurities in external equipment on the experiment to the maximum extent.
5. The highly mechanized preparation method of aluminate with rare earth photoelectric function according to claim 1, wherein in step C, because of poor thermal conductivity of polytetrafluoroethylene and high density difference between rare earth oxide and other raw materials, the freezing step adopts a combined process of contact freezing and non-contact freezing of raw material mixture and liquid nitrogen, that is, liquid nitrogen is present inside and outside the polytetrafluoroethylene beaker, the liquid nitrogen in the polytetrafluoroethylene beaker is directly contacted and frozen with the liquid raw material mixture after high pressure digestion, and simultaneously the liquid nitrogen outside the polytetrafluoroethylene beaker is non-contact frozen with the liquid raw material mixture after high pressure digestion.
CN202111000389.6A 2021-08-27 2021-08-27 Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization Active CN113603129B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111000389.6A CN113603129B (en) 2021-08-27 2021-08-27 Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111000389.6A CN113603129B (en) 2021-08-27 2021-08-27 Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization

Publications (2)

Publication Number Publication Date
CN113603129A CN113603129A (en) 2021-11-05
CN113603129B true CN113603129B (en) 2023-03-14

Family

ID=78342201

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111000389.6A Active CN113603129B (en) 2021-08-27 2021-08-27 Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization

Country Status (1)

Country Link
CN (1) CN113603129B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4024070A (en) * 1974-05-24 1977-05-17 U.S. Philips Corporation Method of manufacturing a cerium activated luminescent rare-earth aluminate
WO2014067109A1 (en) * 2012-10-31 2014-05-08 海洋王照明科技股份有限公司 Aluminate luminescent material and preparation method therefor
CN104528799A (en) * 2014-12-10 2015-04-22 中国地质大学(武汉) Preparation method of ultrafine magnesium-based rare earth hexaaluminate powder
CN113044864A (en) * 2021-03-05 2021-06-29 北京工业大学 Method for preparing alkaline earth metal aluminate for cathode by freeze drying method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4024070A (en) * 1974-05-24 1977-05-17 U.S. Philips Corporation Method of manufacturing a cerium activated luminescent rare-earth aluminate
WO2014067109A1 (en) * 2012-10-31 2014-05-08 海洋王照明科技股份有限公司 Aluminate luminescent material and preparation method therefor
CN104528799A (en) * 2014-12-10 2015-04-22 中国地质大学(武汉) Preparation method of ultrafine magnesium-based rare earth hexaaluminate powder
CN113044864A (en) * 2021-03-05 2021-06-29 北京工业大学 Method for preparing alkaline earth metal aluminate for cathode by freeze drying method

Also Published As

Publication number Publication date
CN113603129A (en) 2021-11-05

Similar Documents

Publication Publication Date Title
CN106221695B (en) The preparation method of aluminum-nitride-based fluorescent powder
CN104761251B (en) A kind of reaction sintering method preparing magnesium aluminate spinel
CN102260500A (en) Method for making nitride/nitrogen oxide fluorescent powder for white light LED (Light Emitting Diode)
CN111019648A (en) Molten salt method preparation method of oxysalt or oxynitride fluorescent powder
CN112851344A (en) Microwave dielectric ceramic with medium dielectric constant and preparation method thereof
CN113044864B (en) Method for preparing alkaline earth metal aluminate for cathode by freeze drying method
CN113603129B (en) Novel approach for synthesizing rare earth-containing photoelectric functional aluminate based on high mechanization
CN101831292A (en) Strontium aluminate luminous material and controllable synthesis method thereof
CN111410958B (en) Method for preparing red fluorescent powder by using LiF as fluxing agent
CN100497518C (en) Process for preparing aluminate luminescent materials
CN115197690B (en) Orange-red fluorescent powder and preparation method thereof
CN105331365A (en) Preparation method of LED fluorescent powder
CN104388081A (en) Synthetic method for aluminate doped with valence-state-controllable rare earth element and product thereof
CN105713604B (en) A kind of preparation method of LED silicate fluorescent powders
CN110396408B (en) Preparation method of small-particle-size YAG (yttrium aluminum garnet) Ce fluorescent powder
CN114133245A (en) Thermoelectric ceramic material and preparation method thereof
CN112480919A (en) High-thermal-stability yellow-green fluorescent powder and preparation method thereof
CN115074119B (en) Be applied to white light LED (Ba, ca)4Al2O7:Eu3+Red fluorescent powder and preparation method thereof
CN106010528A (en) Bismuth-manganese-doped blue fluorescent powder and preparation method and application thereof
CN105984891A (en) Method for preparing nano aluminum oxide at low temperature
CN116376548B (en) Silicon-aluminum-based red fluorescent powder and preparation method thereof
CN104927855B (en) Rare earth borate-based red fluorescent powder
CN105623659B (en) A kind of preparation method of LED titanate fluorescent powders
CN109516800A (en) A kind of high energy-storage property media ceramic, preparation method and applications
CN114921244B (en) Spindle rod-shaped MgAl 2 O 4 :Tb 3+ Fluorescent powder and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant