CN110563010A - preparation method of low-sodium regular hexagonal flaky alpha-alumina micro powder - Google Patents
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Abstract
the invention discloses a preparation method of low-sodium regular hexagonal flaky alpha-alumina micro powder, which takes cheap industrial aluminum hydroxide as a raw material; firstly, mixing industrial aluminum hydroxide, a dispersant and deionized water to prepare slurry; grinding, sodium removal, solid-liquid separation, primary washing, solid-liquid separation, drying, pre-sintering and secondary washing to obtain a low-sodium alumina precursor; then adding a morphology inducer, stirring, mixing and calcining to obtain the low-sodium regular hexagonal flaky alpha-alumina micro powder. The sodium oxide content of the low-sodium regular hexagonal flaky alpha-alumina micro powder prepared by the method is less than 0.05 percent, and the alpha-Al micro powder2O3The content is more than 98 percent, the particle appearance is regular hexagon, the side length is less than 1.5 mu m, the thickness is less than 0.5 mu m, and the method can be applied to the fields of semiconductor materials, single crystal sapphire, reinforcing agents, protective layers and the like. The preparation method has the characteristics of wide raw material source, simple equipment and production process, low production cost, realization of industrial production, environmental friendliness and the like.
Description
Technical Field
the invention relates to a preparation method of alumina powder, in particular to a preparation method of low-sodium regular hexagonal flaky alpha-alumina micro powder.
background
the low-sodium flaky alpha-alumina has excellent performances of high hardness, high melting point, high temperature resistance, corrosion resistance, good thermal conductivity and the like of the conventional alpha-alumina, and has special performances of good adhesive force, obvious shielding effect, light reflection capability and the like due to the special two-dimensional plane structure, so that the low-sodium flaky alpha-alumina has great application potential in the fields of high-end automobile polishing, gem processing, high-precision microelectronic processing, cosmetics, functional coatings, ceramic toughening and the like.
At present, the preparation method of the flaky alumina mainly comprises a hydrothermal method, a molten salt method, a sol-gel method, a mechanical method and the like. The flaky alumina prepared by the hydrothermal method has the characteristic of uniform shape, but the reaction period is long, the reaction process needs to be carried out in a closed system, the requirement on equipment is high, and the process is complex; the molten salt method generally uses aluminum sulfate as a raw material, uses sodium sulfate as molten salt, and calcines the raw material at high temperature to realize the shape control of powder, but some molten salts have toxicity and are harmful to human bodies and the environment; the mechanical method has simple process, simple equipment and low cost, but the purity of the powder is not high and the consistency of the shape is poor. The powder prepared by the sol-gel method has high purity and good particle uniformity, but is prepared by taking expensive high-purity aluminum, aluminum isopropoxide or boehmite as a raw material through hydrolytic polycondensation and condensation, and has the defects of expensive raw material, complex production process, high production cost, small capacity and the like.
disclosure of Invention
the invention provides low-sodium regular hexagonal flaky alpha-Al2O3The micro powder preparation method solves the problems of high production cost, complex production process, high sodium content, difficult control of particle size and morphology and the like in the prior art.
The invention is realized by adopting the following technical scheme:
A preparation method of low-sodium regular hexagonal flaky alpha-alumina micropowder takes industrial aluminum hydroxide as a raw material; firstly, mixing industrial aluminum hydroxide, a dispersant and deionized water to prepare slurry; grinding, sodium removal, solid-liquid separation, primary washing, solid-liquid separation, drying, pre-sintering and secondary washing to obtain a low-sodium alumina precursor; then adding a morphology inducer, stirring, mixing and calcining to obtain the low-sodium regular hexagonal flaky alpha-alumina micro powder.
in the technical scheme, the initial particle of the industrial aluminum hydroxide powder is less than 500 mu m, and the content of sodium oxide is 0.2-0.5 wt%.
further, the dispersant is one or two of polyethylene glycol, triethanolamine, polyacrylamide and polyethyleneimine, and the addition amount of the dispersant is 0.2-2 wt% of industrial aluminum hydroxide.
Further, the content of the industrial aluminum hydroxide in the slurry is 10-30 wt%.
Further, the grinding is carried out by a sand mill, grinding media are zirconia balls or alumina balls, the diameter of the media balls is 1-5 mu m, and the grinding time is 0.5-6 h.
Further, the sodium removing agent used for removing sodium is one of hydrochloric acid, acetic acid, nitric acid or citric acid, and the addition amount of the sodium removing agent is used for adjusting the pH value of the slurry to be 4-7.
Further, the temperature of deionized water adopted for primary washing and secondary washing is 50-100 ℃, the water-material ratio is 5: 1-20: 1, and the washing times are 2-4; the solid-liquid separation is centrifugal separation, the centrifugal speed is 2000-10000 r/min, and the centrifugal time is 10-60 min; the drying is carried out by adopting an oven or a tunnel furnace, the drying temperature is 110-150 ℃, and the drying time is 8-24 h.
Further, the pre-sintering temperature is 550-900 ℃, and the pre-sintering time is 30-120 min.
further, the morphology inducer is aluminum fluoride or ammonium fluoride, and the addition amount of the morphology inducer is 1-2.4 wt% of the low-sodium alumina precursor; the stirring and mixing is dry stirring and mixing, one of dry mechanical stirring, dry ball milling or dry planetary milling is adopted, and the stirring and mixing time is 10-60 min.
Further, the calcination is carried out in a muffle furnace, the sintering temperature is 900-1200 ℃, the heat preservation time is 30-120 min, the temperature rise speed is 5-20 ℃/min, and the cooling mode is furnace cooling to room temperature.
the sodium oxide content of the low-sodium regular hexagonal flaky alpha-alumina micro powder prepared by the method is less than 0.05 percent, and the alpha-Al micro powder2O3the content is more than 98 percent, the particle appearance is regular hexagon, the side length is less than 1.5 mu m, and the thickness is less than 500 nm.
Compared with the prior preparation technology, the invention has the following technical effects:
(1) the invention overcomes the defects of high cost, low efficiency, low purity, serious pollution and the like of preparing alumina micropowder in the prior art, and provides a novel preparation method of high-purity regular hexagonal flaky alumina micropowder. The process has the characteristics of low cost, environmental friendliness, batch production and the like.
(2) the low-sodium regular hexagonal flaky alumina micropowder prepared by the invention has the characteristics of low sodium oxide content, high alpha-alumina content, regular hexagonal flaky shape, micro-nano grade particle size and the like, and has great application potential in the fields of high-end automobile polishing, gem processing, high-precision microelectronic processing, cosmetics, functional coatings, ceramic toughening and the like.
(3) The presintering process can expose more sodium ions wrapped in the crystal lattices of the transition phase alumina, so that the sodium ions and other impurity elements are greatly reduced in secondary washing. The regular hexagonal flaky alpha-alumina with good appearance can be prepared by adding a shape inducer into a low-sodium alumina precursor subjected to multi-stage sodium removal and sintering at a certain temperature.
Drawings
FIG. 1 is a microstructure of the alumina prepared in example 1;
FIG. 2 is an X-ray diffraction pattern of the alumina prepared in example 1;
FIG. 3 is the microstructure of the alumina prepared in example 2;
FIG. 4 is an X-ray diffraction pattern of the alumina prepared in example 2;
FIG. 5 is the microstructure of the alumina prepared in example 3;
FIG. 6 is an X-ray diffraction pattern of the alumina prepared in example 3;
FIG. 7 is a microstructure of the alumina prepared in comparative example 1;
FIG. 8 is an X-ray diffraction pattern of the alumina prepared in comparative example 1;
FIG. 9 is a microstructure of the alumina prepared in comparative example 2;
FIG. 10X-ray diffraction pattern of the alumina prepared in comparative example 2.
Detailed Description
the invention is further described below with reference to the accompanying drawings and specific embodiments.
Low-sodium regular hexagonal flaky alpha-Al2O3The preparation method of the micro powder comprises the following steps:
(1) Mixing and stirring industrial aluminum hydroxide, a dispersing agent and deionized water to prepare aluminum hydroxide slurry with the solid content of 10-30 wt%, and grinding in a sand mill, wherein a grinding medium is zirconia balls, the diameter of each ball is 1-5 mu m, and the grinding time is 0.5-6 h to obtain refined aluminum oxide precursor slurry;
(2) stirring the alumina precursor slurry prepared in the step (1) in a water bath at 70-100 ℃ for 10-60 min, adding a sodium remover while stirring to adjust the pH value of the slurry to 4-7, and obtaining non-alkaline alumina precursor slurry;
(3) and (3) performing solid-liquid separation on the alumina precursor slurry prepared in the step (2) by adopting a high-speed centrifuge to obtain a solid alumina precursor. The centrifugation speed is 2000-10000 r/min, and the centrifugation time is 10-60 min;
(4) And (4) carrying out primary washing and solid-liquid separation on the solid alumina precursor prepared in the step (3) for 2-4 times to obtain the alumina precursor. The temperature of deionized water used in the water washing is 50-100 ℃, and the water-material ratio is 5: 1-20: 1.
(5) Drying the alumina precursor prepared in the step (4) in an oven at 110-150 ℃ for 8-24 h;
(6) And (5) putting the sample obtained in the step (5) into a muffle furnace for pre-sintering, wherein the pre-sintering temperature is 550-900 ℃, and the heat preservation time is 30-120 min. And (5) carrying out secondary washing on the pre-sintered micro powder, repeating the step (4) in the washing process, and drying after washing to obtain the low-sodium alumina precursor.
(7) Adding a morphology inducer aluminum fluoride or ammonium fluoride into the low-sodium alumina precursor prepared in the step (6), uniformly mixing and stirring to prepare uniformly mixed composite micro powder;
(8) And (3) placing the composite micro powder prepared in the step (7) into a muffle furnace for high-temperature calcination, wherein the sintering temperature is 900-1200 ℃, the heat preservation time is 30-120 min, and the temperature rise speed is 5-20 ℃/min. Cooling to room temperature along with the furnace to obtain the high-purity regular hexagonal flaky alumina micropowder.
Example 1
(1) Weighing 6 parts of aluminum hydroxide powder (the initial particle size of the powder is 100 mu m, the content of sodium oxide is 0.35 wt%), 0.1 part of polyacrylamide and 34 parts of deionized water, preparing into 15 wt% aluminum hydroxide slurry, and then putting into a sand mill for grinding to obtain a refined aluminum oxide precursor. The grinding medium is zirconia balls, the diameter of each ball is 2 microns, and the grinding time is 2 hours;
(2) Stirring the alumina precursor slurry prepared in the step (1) in a water bath at 80 ℃ for 30min, and adding hydrochloric acid while stirring to adjust the pH value of the slurry to 4 to obtain non-alkaline alumina precursor slurry;
(3) and (3) performing solid-liquid separation on the alumina precursor slurry prepared in the step (2) in a high-speed centrifuge to obtain a solid alumina precursor. The centrifugation speed is 5000 r/min, and the centrifugation time is 30 min;
(4) And (4) carrying out 3 times of primary water washing and solid-liquid separation on the solid alumina precursor prepared in the step (3) to obtain a low-sodium alumina precursor. The temperature of deionized water used in the water washing is 80 ℃, and the volume ratio of water to materials is 5: 1.
(5) Drying the low-sodium alumina precursor prepared in the step (4) in an oven at 110 ℃ for 20 h;
(6) And (4) calcining the dried low-sodium alumina precursor prepared in the step (5) in a muffle furnace at 700 ℃, and preserving heat for 60 min. And (5) carrying out secondary washing for 2 times according to the washing process in the step (4), and drying for later use.
(7) Adding 1 wt% of morphology inducer ammonium fluoride into the dried low-sodium alumina precursor prepared in the step (6), and mechanically stirring for 0.5h to prepare uniformly mixed composite micro powder;
(8) And (4) calcining the composite micro powder prepared in the step (7) in a box type furnace at 1200 ℃ for 60min to prepare the low-sodium regular hexagonal flaky alpha alumina micro powder.
na of the low-sodium regular hexagonal alpha alumina micropowder prepared in example 12O content of 0.034%, alpha-Al2O3The content is 99.5 percent, the particle appearance is regular hexagon, the side length is about 1000nm, and the thickness is about 300 nm. Scanning electron photographs and X-ray diffraction patterns of the fine powder are shown in fig. 1 and 2, respectively.
Example 2
(1) weighing 7 parts of aluminum hydroxide powder (the initial particle size of the powder is 80 mu m, the content of sodium oxide is 0.30 wt%), 0.21 part of triethanolamine and 33 parts of deionized water, preparing aluminum hydroxide slurry with the concentration of 17.5 wt%, and then putting the aluminum hydroxide slurry into a sand mill for grinding to obtain a refined aluminum oxide precursor. The grinding medium is zirconia balls, the diameter of each zirconia ball is 1 mu m, and the grinding time is 3 h;
(2) Stirring the alumina precursor slurry prepared in the step (1) in a water bath at 90 ℃ for 30min, adding nitric acid while stirring to adjust the pH value of the slurry to 5, and obtaining non-alkaline alumina precursor slurry;
(3) and (3) performing solid-liquid separation on the alumina precursor slurry prepared in the step (2) in a high-speed centrifuge to obtain a solid alumina precursor. The centrifugation speed is 6000 r/min, and the centrifugation time is 30 min;
(4) and (4) carrying out 3-time primary washing and centrifugal solid-liquid separation on the solid alumina precursor prepared in the step (3) to obtain a low-sodium alumina precursor. The temperature of deionized water used in the water washing is 90 ℃, and the volume ratio of water to materials is 10: 1.
(5) drying the low-sodium alumina precursor prepared in the step (4) in a drying oven at 110 ℃ for 24 hours;
(6) And (4) calcining the dried low-sodium alumina precursor prepared in the step (5) in a muffle furnace at 600 ℃, and preserving heat for 60 min. And (5) carrying out secondary washing for 2 times according to the washing process in the step (4), and drying for later use.
(7) adding 1.8 wt% of aluminum fluoride as a morphology inducer aluminum fluoride into the dried low-sodium alumina precursor prepared in the step (6), and mechanically stirring for 20min to prepare uniformly mixed composite micro powder;
(8) And (4) calcining the composite micro powder prepared in the step (7) in a box type furnace at 1100 ℃ for 90min to prepare the low-sodium regular hexagonal alpha alumina micro powder.
na of the low-sodium regular hexagonal alpha alumina micropowder prepared in example 22o content of 0.028%, alpha-Al2O3The content is 99.1 percent, the particle appearance is regular hexagon, the side length is about 800nm, and the thickness is about 250 nm. Scanning electron photographs and X-ray diffraction patterns of the fine powder are shown in fig. 3 and 4, respectively.
Example 3
(1) Weighing 8 parts of aluminum hydroxide powder (the initial particle size of the powder is 120 mu m, the content of sodium oxide is 0.27 wt%), 0.15 part of triethanolamine and 32 parts of deionized water, preparing 20 wt% aluminum hydroxide slurry, and then putting the aluminum hydroxide slurry into a sand mill for grinding to obtain a refined aluminum oxide precursor. The grinding medium is zirconia balls, the diameter of each zirconia ball is 3 mu m, and the grinding time is 5 h;
(2) stirring the alumina precursor slurry prepared in the step (1) in a water bath at 95 ℃ for 50min, adding citric acid while stirring to adjust the pH value of the slurry to 6, and obtaining non-alkaline alumina precursor slurry;
(3) And (3) performing solid-liquid separation on the alumina precursor slurry prepared in the step (2) in a high-speed centrifuge to obtain a solid alumina precursor. The centrifugation speed is 7000 r/min, and the centrifugation time is 40 min;
(4) And (4) carrying out 2-time primary washing and solid-liquid separation on the solid alumina precursor prepared in the step (3) to obtain a low-sodium alumina precursor. The temperature of deionized water used in the water washing is 95 ℃, and the volume ratio of water to materials is 20: 1.
(5) Drying the low-sodium alumina precursor prepared in the step (4) in a drying oven at 150 ℃ for 24 hours;
(6) And (4) calcining the dried low-sodium alumina precursor prepared in the step (5) in a muffle furnace at 700 ℃, and preserving heat for 45 min. And (5) carrying out secondary washing for 2 times according to the washing process in the step (4), and drying for later use.
(7) Adding 2 wt% of morphology inducer ammonium fluoride into the dried low-sodium alumina precursor prepared in the step (6), and mechanically stirring and mixing for 10min to prepare uniformly mixed composite micro powder;
(8) and (4) placing the composite micro powder prepared in the step (7) into a box type furnace for sintering to obtain the low-sodium regular hexagonal nano alumina micro powder. The sintering temperature is 1050 ℃, the heat preservation time is 120min, the temperature rising speed is 10 ℃/min, and the sintering temperature is cooled to the room temperature along with the furnace.
Na of the low-sodium regular hexagonal alpha alumina micropowder prepared in example 32O content of 0.021%, alpha-Al2O3The content is 98.5 percent, the particle appearance is regular hexagon, the side length is about 500nm, and the thickness is about 180 nm. Scanning electron photographs and X-ray diffraction patterns of the fine powder are shown in fig. 5 and 6, respectively.
comparative example 1:
(1) Weighing 6 parts of aluminum hydroxide powder (the initial particle size of the powder is 100 mu m, the content of sodium oxide is 0.35 wt%), 0.1 part of polyacrylamide and 34 parts of deionized water, preparing into 15 wt% aluminum hydroxide slurry, and then putting into a sand mill for grinding to obtain a refined aluminum oxide precursor. The grinding medium is zirconia balls, the diameter of each ball is 2 microns, and the grinding time is 2 hours;
(2) stirring the alumina precursor slurry prepared in the step (1) in a water bath at 80 ℃ for 30min, and adding hydrochloric acid while stirring to adjust the pH value of the slurry to 4 to obtain non-alkaline alumina precursor slurry;
(3) And (3) performing solid-liquid separation on the alumina precursor slurry prepared in the step (2) in a high-speed centrifuge to obtain a solid alumina precursor. The centrifugation speed is 5000 r/min, and the centrifugation time is 30 min;
(4) And (4) carrying out 3 times of primary water washing and solid-liquid separation on the solid alumina precursor prepared in the step (3) to obtain a low-sodium alumina precursor. The temperature of deionized water used in the water washing is 80 ℃, and the volume ratio of water to materials is 5: 1.
(5) drying the low-sodium alumina precursor prepared in the step (4) in an oven at 110 ℃ for 20 h;
(6) And (4) carrying out secondary washing for 2 times on the low-sodium alumina precursor prepared in the step (5) according to the washing process in the step (4), and drying for later use.
(7) Adding 1 wt% of morphology inducer ammonium fluoride into the dried low-sodium alumina precursor prepared in the step (6), and mechanically stirring for 0.5h to prepare uniformly mixed composite micro powder;
(8) And (4) calcining the composite micro powder prepared in the step (7) in a box type furnace at 1200 ℃ for 60min to prepare the low-sodium flaky alpha alumina micro powder.
Na of low-sodium flaky alpha alumina micropowder prepared in comparative example 12O content of 0.097%, alpha-Al2O3The content is 94.5 percent, the particle appearance is irregular flake alumina, the side length is about 1000nm, and the thickness is about 500 nm. Scanning electron photographs and X-ray diffraction patterns of the fine powder are shown in fig. 7 and 8, respectively.
comparative example 2
(1) Weighing 7 parts of aluminum hydroxide powder (the initial particle size of the powder is 80 mu m, the content of sodium oxide is 0.30 wt%), 0.21 part of triethanolamine and 33 parts of deionized water, preparing aluminum hydroxide slurry with the concentration of 17.5 wt%, and then putting the aluminum hydroxide slurry into a sand mill for grinding to obtain a refined aluminum oxide precursor. The grinding medium is zirconia balls, the diameter of each zirconia ball is 1 mu m, and the grinding time is 3 h;
(2) Stirring the alumina precursor slurry prepared in the step (1) in a water bath at 90 ℃ for 30min, adding nitric acid while stirring to adjust the pH value of the slurry to 5, and obtaining non-alkaline alumina precursor slurry;
(3) and (3) performing solid-liquid separation on the alumina precursor slurry prepared in the step (2) in a high-speed centrifuge to obtain a solid alumina precursor. The centrifugation speed is 6000 r/min, and the centrifugation time is 30 min;
(4) And (4) carrying out washing and centrifugal solid-liquid separation on the solid alumina precursor prepared in the step (3) for 3 times to obtain a low-sodium alumina precursor. The temperature of deionized water used in the water washing is 90 ℃, and the volume ratio of water to materials is 10: 1.
(5) Drying the low-sodium alumina precursor prepared in the step (4) in a drying oven at 110 ℃ for 24 hours;
(6) and (4) calcining the dried low-sodium alumina precursor prepared in the step (5) in a muffle furnace at 600 ℃, and preserving heat for 60 min.
(7) Adding 1.8 wt% of aluminum fluoride as a morphology inducer aluminum fluoride into the low-sodium aluminum oxide precursor prepared in the step (6), and mechanically stirring for 20min to prepare uniformly mixed composite micro powder;
(8) and (4) calcining the composite micro powder prepared in the step (7) in a box type furnace at 1100 ℃ for 90min to prepare the low-sodium flaky alpha alumina micro powder.
Na of low-sodium flaky alpha alumina fine powder prepared in comparative example 22o content of 0.11%, alpha-Al2O391.0 percent of the total aluminum oxide, the particle morphology is irregular flake aluminum oxide, the side length is about 1500nm, and the thickness is about 300 nm. Scanning electron photographs and X-ray diffraction patterns of the fine powder are shown in fig. 9 and 10, respectively.
Claims (10)
1. A preparation method of low-sodium regular hexagonal flaky alpha-alumina micropowder is characterized by comprising the following steps: industrial aluminum hydroxide is used as a raw material; firstly, mixing industrial aluminum hydroxide, a dispersant and deionized water to prepare slurry; grinding, sodium removal, solid-liquid separation, primary washing, solid-liquid separation, drying, pre-sintering and secondary washing to obtain a low-sodium alumina precursor; then adding a morphology inducer, stirring, mixing and calcining to obtain the low-sodium regular hexagonal flaky alpha-alumina micro powder.
2. The method for preparing the low-sodium regular hexagonal flaky alpha-alumina micropowder according to claim 1, wherein the initial particle of the industrial aluminum hydroxide powder is less than 500 μm, and the sodium oxide content is 0.2-0.5 wt%.
3. The preparation method of the low-sodium regular hexagonal flaky alpha-alumina micropowder according to claim 1, wherein the dispersant is one or two of polyethylene glycol, triethanolamine, polyacrylamide and polyethyleneimine, and the addition amount of the dispersant is 0.2-2 wt% of industrial aluminum hydroxide.
4. The method for preparing the low-sodium regular hexagonal flaky alpha-alumina micropowder according to claim 1, wherein the content of industrial aluminum hydroxide in the slurry is 10 to 30 wt%.
5. The preparation method of the low-sodium regular hexagonal flaky alpha-alumina micropowder according to claim 1, wherein the grinding is carried out by a sand mill, the grinding medium is zirconia balls or alumina balls, the diameter of the medium balls is 1-5 μm, and the grinding time is 0.5-6 h.
6. the preparation method of the low-sodium regular-hexagonal flaky alpha-alumina micropowder according to claim 1, wherein the sodium remover used for sodium removal is one of hydrochloric acid, acetic acid, nitric acid or citric acid, and the addition amount of the sodium remover is such that the pH value of the slurry is adjusted to 4-7.
7. the preparation method of the low-sodium regular hexagonal flaky alpha-alumina micropowder according to claim 1, wherein the temperature of deionized water adopted for the primary washing and the secondary washing is 50-100 ℃, the water-material ratio is 5: 1-20: 1, and the washing frequency is 2-4 times; the solid-liquid separation is centrifugal separation, the centrifugal speed is 2000-10000 r/min, and the centrifugal time is 10-60 min; the drying is carried out by adopting an oven or a tunnel furnace, the drying temperature is 110-150 ℃, and the drying time is 8-24 h.
8. The preparation method of the regular hexagonal flaky alumina micropowder according to claim 1, wherein the pre-sintering temperature is 550 to 900 ℃ and the pre-sintering time is 30 to 120 min.
9. The preparation method of the regular hexagonal flaky alumina micropowder according to claim 1, wherein the morphology inducer is aluminum fluoride or ammonium fluoride, and the addition amount of the morphology inducer is 1-2.4 wt% of the low-sodium alumina precursor; the stirring and mixing is dry stirring and mixing, one of dry mechanical stirring, dry ball milling or dry planetary milling is adopted, and the stirring and mixing time is 10-60 min.
10. the preparation method of the regular hexagonal flaky alumina micropowder according to claim 1, wherein the calcination is carried out in a muffle furnace, the sintering temperature is 900-1200 ℃, the holding time is 30-120 min, the temperature rise rate is 5-20 ℃/min, and the cooling mode is furnace cooling to room temperature.
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Cited By (6)
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| CN113651345A (en) * | 2021-08-12 | 2021-11-16 | 中化学科学技术研究有限公司 | Morphology control method for high-purity flaky boehmite |
| CN114057505A (en) * | 2021-12-13 | 2022-02-18 | 西安邮电大学 | Preparation method of porous flaky alumina framework |
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| CN113651345A (en) * | 2021-08-12 | 2021-11-16 | 中化学科学技术研究有限公司 | Morphology control method for high-purity flaky boehmite |
| CN113651345B (en) * | 2021-08-12 | 2023-05-26 | 中化学科学技术研究有限公司 | High-purity flaky boehmite morphology control method |
| CN114057505A (en) * | 2021-12-13 | 2022-02-18 | 西安邮电大学 | Preparation method of porous flaky alumina framework |
| CN114057505B (en) * | 2021-12-13 | 2023-02-28 | 西安邮电大学 | Preparation method of porous flaky alumina framework |
| CN114988886A (en) * | 2022-06-01 | 2022-09-02 | 洛阳中超新材料股份有限公司 | Preparation method of high-purity alpha-alumina powder capable of being sintered at low temperature |
| CN115073147A (en) * | 2022-06-28 | 2022-09-20 | 浙江自立新材料股份有限公司 | Preparation method of low-sodium and ultra-low-sodium tabular sintered corundum |
| CN115974112A (en) * | 2022-12-15 | 2023-04-18 | 西北工业大学 | Low-sodium submicron alpha-alumina powder and preparation method and application thereof |
| CN115894072A (en) * | 2022-12-29 | 2023-04-04 | 江苏省宜兴非金属化工机械厂有限公司 | Corrosion-resistant ceramic filter plate and preparation method thereof |
| CN115894072B (en) * | 2022-12-29 | 2024-03-08 | 江苏省宜兴非金属化工机械厂有限公司 | Corrosion-resistant ceramic filter plate and preparation method thereof |
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