CN116854118A - Preparation method of high-purity spherical aluminum hydroxide, high-purity spherical aluminum hydroxide and high-purity alumina microsphere - Google Patents
Preparation method of high-purity spherical aluminum hydroxide, high-purity spherical aluminum hydroxide and high-purity alumina microsphere Download PDFInfo
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- CN116854118A CN116854118A CN202310609230.7A CN202310609230A CN116854118A CN 116854118 A CN116854118 A CN 116854118A CN 202310609230 A CN202310609230 A CN 202310609230A CN 116854118 A CN116854118 A CN 116854118A
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- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 title claims abstract description 146
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims abstract description 44
- 239000004005 microsphere Substances 0.000 title claims abstract description 28
- 238000002360 preparation method Methods 0.000 title claims abstract description 12
- 239000013078 crystal Substances 0.000 claims abstract description 70
- 238000000354 decomposition reaction Methods 0.000 claims abstract description 62
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 claims abstract description 51
- 239000002245 particle Substances 0.000 claims abstract description 51
- 229910001388 sodium aluminate Inorganic materials 0.000 claims abstract description 51
- 238000000034 method Methods 0.000 claims abstract description 39
- 238000006386 neutralization reaction Methods 0.000 claims abstract description 24
- 125000004122 cyclic group Chemical group 0.000 claims abstract description 9
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims abstract description 9
- 238000005406 washing Methods 0.000 claims abstract description 8
- 229910021502 aluminium hydroxide Inorganic materials 0.000 claims abstract description 5
- 238000004131 Bayer process Methods 0.000 claims description 17
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 10
- 238000000227 grinding Methods 0.000 claims description 10
- 238000000926 separation method Methods 0.000 claims description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 238000006555 catalytic reaction Methods 0.000 claims description 5
- 238000010335 hydrothermal treatment Methods 0.000 claims description 3
- 230000007547 defect Effects 0.000 abstract description 4
- 239000000243 solution Substances 0.000 description 47
- 239000000047 product Substances 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 239000002994 raw material Substances 0.000 description 10
- 238000003756 stirring Methods 0.000 description 10
- 238000007405 data analysis Methods 0.000 description 9
- 239000007787 solid Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 239000002253 acid Substances 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 7
- 238000004090 dissolution Methods 0.000 description 7
- 238000001914 filtration Methods 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000002002 slurry Substances 0.000 description 6
- 239000012498 ultrapure water Substances 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- 239000000178 monomer Substances 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- 239000002243 precursor Substances 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 239000003513 alkali Substances 0.000 description 4
- -1 aluminum alkoxide Chemical class 0.000 description 4
- 239000011325 microbead Substances 0.000 description 4
- 238000010899 nucleation Methods 0.000 description 4
- 230000006911 nucleation Effects 0.000 description 4
- 238000001878 scanning electron micrograph Methods 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- 238000001354 calcination Methods 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 235000019441 ethanol Nutrition 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000011858 nanopowder Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000000197 pyrolysis Methods 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 230000001627 detrimental effect Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 238000004321 preservation Methods 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 238000012216 screening Methods 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- FJNQSTUXQFLBIS-UHFFFAOYSA-H [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[U+6] Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[U+6] FJNQSTUXQFLBIS-UHFFFAOYSA-H 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- IOGARICUVYSYGI-UHFFFAOYSA-K azanium (4-oxo-1,3,2-dioxalumetan-2-yl) carbonate Chemical compound [NH4+].[Al+3].[O-]C([O-])=O.[O-]C([O-])=O IOGARICUVYSYGI-UHFFFAOYSA-K 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000012295 chemical reaction liquid Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012847 fine chemical Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 239000006148 magnetic separator Substances 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 238000012946 outsourcing Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000004537 pulping Methods 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 238000010900 secondary nucleation Methods 0.000 description 1
- 210000000582 semen Anatomy 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 239000000375 suspending agent Substances 0.000 description 1
- 238000010557 suspension polymerization reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/14—Aluminium oxide or hydroxide from alkali metal aluminates
- C01F7/141—Aluminium oxide or hydroxide from alkali metal aluminates from aqueous aluminate solutions by neutralisation with an acidic agent
- C01F7/142—Aluminium oxide or hydroxide from alkali metal aluminates from aqueous aluminate solutions by neutralisation with an acidic agent with carbon dioxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/30—Particle morphology extending in three dimensions
- C01P2004/32—Spheres
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
Abstract
A preparation method of high-purity spherical aluminum hydroxide, high-purity spherical aluminum hydroxide and a high-purity alumina microsphere comprise the following steps: (1) Adding sodium aluminate solution into aluminium hydroxide seed crystal, introducing CO 2 Performing carbonation neutralization decomposition to obtain aluminum hydroxide; (2) Adding the obtained aluminum hydroxide as seed crystal into new sodium aluminate solution again, and carrying out carbonation neutralization decomposition; (3) Repeating the step (2) for 4-10 times, carrying out repeated cyclic carbonation neutralization decomposition, separating and washing to obtain high-purity spherical aluminum hydroxide; wherein the particle size D of the aluminum hydroxide seed crystal 50 70-100 μm. The method is to carry out repeated cyclic carbonation neutralization and decomposition, so that the seed crystal is continuously grown and large, and the surface defect is filled up once until the seed crystal grows into spherical aluminum hydroxide with a flat surface; the sphericity of the spherical aluminum hydroxide prepared by the application is 80-95%, the grain diameter is 90-150 mu m, the purity is 99.9%, and the high-purity spherical aluminum oxide product can be prepared by roasting.
Description
Technical Field
The application belongs to the technical field of various alumina, and particularly relates to a preparation method of high-purity spherical aluminum hydroxide.
Background
The spherical alumina belongs to a fine chemical product in an alumina material family, has outstanding compression molding and sintering characteristics, can greatly improve the quality of ceramic products, can avoid scratches in regular morphology, and is favorable for being used as polishing and grinding materials. In the petrochemical industry, the superfine spherical alumina powder directly used as the catalyst can reduce abrasion and prolong the service life of the catalyst, thereby reducing the production cost. The aluminum oxide can be obtained by roasting spherical aluminum hydroxide, and the current production methods of the spherical aluminum hydroxide are various and mainly comprise the following steps: rolling forming, extrusion forming, oil ammonia column, hot oil column, sol gel, template agent method, etc.
CN110204316a provides a preparation method of high-purity alumina grinding microbeads, which comprises the following main technical scheme: grinding and crushing the high-purity alumina powder to obtain high-purity alumina nano powder, wherein the average particle size is required to be 100-500 nm; uniformly mixing high-purity alumina nano powder, an organic monomer and water to obtain an inorganic-organic mixture, wherein the mass ratio of the high-purity alumina nano powder to the organic monomer is 40:100-100:100, and the mass ratio of the organic monomer to the water is 10:100-30:100; adding an initiator accounting for 0.05-5% of the mass of the organic monomer and a suspending agent accounting for 0.1-10% of the mass of the organic monomer into the inorganic-organic mixture, uniformly stirring, and performing bead polymerization reaction to obtain a reaction solution containing a bead precursor; separating, cleaning and drying reaction liquid containing the microsphere precursor to obtain a microsphere blank; and rolling and screening the microbead blank, discharging glue at low temperature, sintering, and screening out damaged microbeads with poor sphericity to obtain the high-purity alumina grinding microbeads.
CN101214984B discloses a method for preparing alumina microsphere, which comprises the following specific steps: (1) placing the feedstock in a crucible; (2) Pyrolyzing raw materials placed in a crucible at 1150-1350 ℃ by using a sintering furnace; (3) pyrolysis and heat preservation for 0.5-1.5 h; (4) furnace cooling to room temperature. Compared with the prior art, the method has the advantages that the alumina microsphere with perfect sphere structure is formed by pyrolysis of the polymer precursor, no protective atmosphere or catalyst is needed, the equipment and the process are simple, the production period is short, the product purity is high, the process controllability and repeatability are good, the monocrystal and polycrystal alumina microsphere can be obtained by controlling the pyrolysis temperature, and the particle size of the microsphere can be regulated and controlled by controlling the heat preservation time.
CN108258231B discloses a preparation method of porous alumina microsphere, the main technical scheme is: step 1, dissolving polyvinylpyrrolidone in absolute ethyl alcohol, ultrasonically stirring for 20-40 min, and cooling to obtain a dispersion alcohol solution; step 2, adding ammonium aluminum carbonate and sodium chloride into the dispersion alcohol solution, and uniformly stirring to form a uniform suspension; step 3, placing the suspension into a reduced pressure distillation reaction kettle for reduced pressure distillation reaction for 20-50 min to obtain a viscous concentrated solution; step 4, adding the viscous concentrated solution into a die, and slowly heating until ethanol is completely removed to obtain an alumina microsphere precursor; step 5, putting the alumina microsphere precursor into a muffle furnace for gradient pressurizing reaction for 2-4 h, slowly releasing pressure, then performing gradient sintering reaction for 4-6 h, and naturally cooling to obtain porous alumina microspheres; and 6, putting the porous alumina microspheres into deionized water for ultrasonic reaction for 3-4 hours, taking out and drying to obtain the porous alumina microspheres.
CN114735734a discloses a method for preparing soluble aluminium hydroxide by bayer process. The method disclosed by the application adopts carbon decomposition to prepare seed crystals, then adds the seed crystals into Bayer process semen to carry out seed decomposition to prepare aluminum hydroxide products, improves the technological conditions of carbon decomposition and seed decomposition, reduces the granularity of single crystal particles, increases the agglomeration granularity of the seed crystals, and thus, the crystal forms of the finally prepared aluminum hydroxide products are different from those of aluminum hydroxide prepared by a conventional Bayer process, and easily soluble aluminum hydroxide products with coarse granularity and high acid dissolution rate are prepared. Aluminum hydroxide prepared by the method of the application is graded D 50 The granularity is above 90 mu m, the acid dissolution rate is above 90% under the conditions of the hydrochloric acid concentration of 21%, the temperature of 95 ℃, the aluminum hydroxide mass fraction of 15% and the reaction time of 1h, and is greatly higher than the acid dissolution rate of 55-65% of the conventional aluminum hydroxide. In addition, the method fully utilizes the aluminum in the aluminum hydroxide washing liquor of the Bayer process, greatly reduces the consumption of aluminum salt raw materials and reduces the production cost.
CN101450811a discloses a method for extracting alumina from coal gangue, which comprises the following main technical scheme: grinding coal into stone powder and then passing through a fluidized bed furnace; removing iron by a strand firing and magnetic separator, reacting the iron-removed pestle with acid to obtain an alumina solution without silicon impurities, concentrating and crystallizing the alumina solution, calcining at low temperature to obtain coarse alumina, reacting the coarse alumina with uranium hydroxide to obtain uranium metaaluminate mother liquor, removing iron and iron impurities, and adding hydrogen into the mother liquorAlumina seed and CO feed 2 And (3) performing seed precipitation on the gas to obtain aluminum hydroxide precipitate, and calcining to obtain metallurgical-grade aluminum oxide. The method uses hydrochloric acid and sulfuric acid to directly leach and extract alumina under normal pressure without any auxiliary agent.
CN1552925a discloses a method for processing industrial waste, which is waste in the aluminum and secondary aluminum smelting industry and the aluminum and aluminum alloy application industry, comprising: 60 to 90 parts by weight of Al 2 O 3 0 to 20 parts by weight of Al,0 to 15 parts by weight of SiO 2 And may further comprise 0 to 15 parts by weight of impurities. The processing method sequentially comprises the following steps: (1) dissolution: the raw materials are dissolved out under the conditions of the dissolution temperature of 70-220 ℃, the caustic alkali concentration of 100-220 g/L and the dissolution time of 0.2-8 h, so as to form sodium aluminate solution: (2) separation: carrying out liquid-solid separation on the dissolved slurry to obtain a sodium aluminate solution: (3) decomposition: adding aluminium hydroxide seed crystal into sodium aluminate solution for seed decomposition or introducing CO 2 Performing carbonation decomposition to obtain aluminum hydroxide: (4) roasting: roasting aluminum hydroxide at 500-1500 deg.c to obtain alumina. The two patents describe a process for producing soluble aluminum hydroxide by carbon seed precipitation, which comprises adding carbonated decomposed aluminum hydroxide (with higher activity) as seed crystal into sodium aluminate solution for seed precipitation decomposition to prepare aluminum hydroxide, decomposing the aluminum hydroxide once to obtain a product, loosening and dissolving the product easily in acid, taking the product as an aluminum hydroxide raw material for acid dissolution, and roasting the aluminum hydroxide to obtain aluminum oxide, wherein the obtained metallurgical-grade aluminum oxide product has poor shape and low quality, and does not accord with the application in the fields of high heat conduction, grinding, catalysis and the like at present.
In order to solve the above problems, there is a need to prepare aluminum hydroxide with high sphericity and purity, and to obtain an alumina product with high sphericity and purity after calcination.
Disclosure of Invention
In order to solve the above problems, the present application proposes a method for preparing high purity spherical aluminum hydroxide, wherein the sphericity of spherical aluminum hydroxide is >90%, the particle size is 90-150 μm, the purity is 99.9%, the purity of high purity alumina microsphere is >99.99%, and sphericity is >90%.
The preparation method of the high-purity spherical aluminum hydroxide comprises the following steps:
(1) Adding sodium aluminate solution into aluminium hydroxide seed crystal, introducing CO 2 Performing carbonation neutralization decomposition to obtain aluminum hydroxide;
(2) Adding the obtained aluminum hydroxide as seed crystal into new sodium aluminate solution again, and carrying out carbonation neutralization decomposition;
(3) Repeating the step (2) for 4-10 times, carrying out repeated cyclic carbonation neutralization decomposition, separating and washing to obtain high-purity spherical aluminum hydroxide;
particle size D of the aluminum hydroxide seed crystal 50 70-100 μm.
Preferably, the aluminum hydroxide seed crystal is a high-purity aluminum hydroxide (purity 99.9%) seed crystal, and the high-purity aluminum hydroxide seed crystal is selected from aluminum alkoxide high-purity aluminum hydroxide, modified Bayer process high-purity aluminum hydroxide, carbon separation process high-purity aluminum hydroxide, seed separation process high-purity aluminum hydroxide and ammonium salt process high-purity aluminum hydroxide.
Preferably, the aluminum hydroxide seed crystals are selected from modified bayer process high purity aluminum hydroxide.
Preferably, the addition amount of the aluminum hydroxide seed crystal is 200 to 400g/L.
Preferably, the carbonation neutralization decomposition temperature is 70 to 90 ℃ and the time is 1h.
Preferably, al of sodium aluminate 2 O 3 The content is 70-120 g/L.
Preferably, the sodium aluminate solution is prepared by the following steps: the method comprises the steps of taking high-purity sodium aluminate solid as a raw material, taking high-purity water as a solvent for pulping and blending, filtering the obtained sodium aluminate solution, and removing insoluble matters to obtain the sodium aluminate solution.
Preferably, CO 2 The concentration is 30-40%.
Preferably, CO 2 The concentration blending method comprises the following steps: adopts outsourcing food-grade high-purity CO 2 The concentration is 100 percent, the purity is 99.99 percent, and the air purified by three stages of air is used for dilution to obtain CO with the concentration of 30 to 40 percent 2 。
Preferably, the sphericity of the obtained high-purity spherical aluminum hydroxide is 80-95%, the particle size is 90-150 μm, and the purity is 99.9%.
Preferably, the high purity alumina microspheres have a purity of >99.99% and a sphericity of >90%;
preferably, the preparation method of the high-purity alumina microsphere comprises the following steps: carrying out hydrothermal treatment on high-purity spherical aluminum hydroxide at 200 ℃ for 2 hours, filtering, washing, drying, and roasting at 1200 ℃ to obtain the high-purity aluminum oxide microspheres. The high-purity alumina microsphere is applied to the fields of high heat conduction, grinding, catalysis and the like.
The application adopts high-purity aluminum hydroxide as seed crystal, adds the seed crystal into sodium aluminate solution and uses CO 2 For decomposing the neutralizer, carbonation neutralization decomposition is carried out by adjusting the concentration, the temperature and the CO of each component of the sodium aluminate solution 2 The method has the advantages that the method realizes continuous growth of aluminum hydroxide precipitated from sodium aluminate solution on coarse-grain aluminum hydroxide crystal faces by various parameters such as ventilation speed, time and the like, aims at sphericizing aluminum hydroxide, enables the aluminum hydroxide to grow and the particle morphology to be more and more sphericized by repeated cyclic carbonation neutralization and decomposition, finally obtains a high-purity spherical aluminum hydroxide product with uniform crystal phase, and is mainly applied to the fields of high heat conduction, grinding, catalysis and the like after roasting.
The application has the following beneficial effects:
1. in the application, high-purity aluminum hydroxide seed crystal is added into sodium aluminate solution, and CO is introduced 2 The high-purity aluminum hydroxide seed crystal is continuously grown under the decomposition condition by carrying out repeated cyclic carbonation neutralization decomposition, and the surface defects are filled and flattened once and again until the high-purity aluminum hydroxide seed crystal is grown into spherical aluminum hydroxide with a flat surface;
2. the application selects the granularity D of the high-purity aluminum hydroxide seed crystal 50 70-100 μm, which is to ensure that the seed crystal is not decomposed too fast in the sodium aluminate solution and can grow smoothly into a sphere; if the aluminum hydroxide seed crystal is too thin, the activity of the seed crystal is too high, and the seed crystal is easy to decompose in the sodium aluminate solution, so that the growth rate of the seed crystal into a sphere is slowed down;
3. the spherical aluminum hydroxide prepared by the method can be prepared into a high-purity spherical aluminum oxide product by roasting, and is mainly applied to the fields of high heat conduction, grinding, catalysis and the like;
4. the spherical aluminum hydroxide prepared by the application has the sphericity of 80-95%, the grain diameter of 90-150 mu m and the purity of 99.9%;
5. the purity of the high-purity alumina microsphere prepared by the method is more than 99.99 percent, and the sphericity is more than 90 percent;
6. the application has the advantages of simple and stable process and low cost, and has good market popularization and application values.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application.
FIG. 1 is an SEM image of spherical aluminum hydroxide obtained in example 1;
FIG. 2 is an SEM image of aluminum hydroxide obtained in comparative experiment 1 without seed crystal added;
Detailed Description
Example 1: (1) High purity sodium aluminate solids (Al 2 O 3 Content of 41%, na 2 30% of O and 99.9% of purity), high-purity water (resistance greater than 13 kiloΩ) is used as solvated slurry, and Al in sodium aluminate solution is regulated 2 O 3 The concentration is 90g/L, and the sodium aluminate solution is obtained after filtration.
(2) With food-grade high purity CO 2 (purity 99.99%) as raw material, air was three-stage filtered to obtain CO 2 Is mixed by mixing to obtain CO with concentration of 35% 2 And (3) gas.
(3) Adding modified Bayer process aluminum hydroxide seed crystals to 1L of sodium aluminate solution according to 300g/L, and obtaining the granularity D 50 80 μm, 99.9% pure, and 35% CO was introduced 2 Performing carbonation neutralization decomposition, and starting stirring for 200r/m, wherein the decomposition temperature is 90 ℃, and the decomposition time is 1h to obtain aluminum hydroxide;
(4) Adding the obtained aluminum hydroxide as seed crystal into new sodium aluminate solution again, and carrying out carbonation neutralization decomposition;
(5) Repeating the step (4) for 6 times, separating and washing to obtain high-purity spherical aluminum hydroxide with the granularity D 50 148 μm and a sphericity of 92%.
Example 2: (1) High purity sodium aluminate solids (Al 2 O 3 Content of 41%, na 2 30% of O and 99.9% of purity), high-purity water (resistance greater than 13 kiloΩ) is used as solvated slurry, and is adjusted to sodium aluminate solution Al 2 O 3 The concentration is 90g/L, and the sodium aluminate solution is obtained after filtration.
(2) With food-grade high purity CO 2 (purity 99.99%) as raw material, air was three-stage filtered to obtain CO 2 Is mixed by mixing to obtain 30% CO 2 And (3) gas.
(3) Adding high-purity aluminum hydroxide seed crystal of aluminum alkoxide method into 1L sodium aluminate solution according to 300g/L, and obtaining the granularity D 50 70 μm, 99.9% pure, and 30% CO was introduced 2 Performing carbonation neutralization decomposition, and starting stirring for 200r/m, wherein the decomposition temperature is 90 ℃, and the decomposition time is 1h to obtain aluminum hydroxide;
(4) Adding the obtained aluminum hydroxide as seed crystal into new sodium aluminate solution again, and carrying out carbonation neutralization decomposition;
(5) Repeating the step (4) for 6 times, separating and washing to obtain high-purity spherical aluminum hydroxide with the granularity D 50 102 μm and a sphericity of 81%.
Example 3: (1) High purity sodium aluminate solids (Al 2 O 3 Content of 41%, na 2 30% of O and 99.9% of purity), high-purity water (resistance greater than 13 kiloΩ) is used as solvated slurry, and is adjusted to sodium aluminate solution Al 2 O 3 The concentration is 90g/L, and the sodium aluminate solution is obtained after filtration.
(2) With food-grade high purity CO 2 (purity 99.99%) as raw material, air was three-stage filtered to obtain CO 2 Is mixed by mixing to obtain CO with concentration of 40% 2 And (3) gas.
(3) Adding high-purity aluminum hydroxide seed crystal of carbon separation method into 1L of aluminum according to 300g/LSodium acid solution, particle size D 50 100 μm, 99.9% pure, and 40% CO was introduced 2 Performing carbonation neutralization decomposition, and starting stirring for 200r/m, wherein the decomposition temperature is 90 ℃, and the decomposition time is 1h to obtain aluminum hydroxide;
(4) Adding the obtained aluminum hydroxide as seed crystal into new sodium aluminate solution again, and carrying out carbonation neutralization decomposition;
(5) Repeating the step (4) for 6 times, separating and washing to obtain high-purity spherical aluminum hydroxide with the granularity D 50 136 μm and a sphericity of 87%.
Example 4: unlike example 1, the particle size D of the Bayer process aluminum hydroxide seed crystals is modified in step (3) 50 70 μm to finally obtain high-purity spherical aluminum hydroxide with the granularity D 50 97 μm and a sphericity of 89%.
Example 5: unlike example 1, the particle size D of the Bayer process aluminum hydroxide seed crystals is modified in step (3) 50 100 μm to finally obtain high-purity spherical aluminum hydroxide with the granularity D 50 143 μm and a sphericity of 83%.
Example 6: unlike example 1, in step (3), modified Bayer process aluminum hydroxide seed crystals were added at 200g/L to 1L of sodium aluminate solution to finally obtain high purity spherical aluminum hydroxide of particle size D 50 126 μm and a sphericity of 91%.
Example 7: unlike example 1, in step (3), modified Bayer process aluminum hydroxide seed crystals were added at 400g/L to 1L of sodium aluminate solution to finally obtain high purity spherical aluminum hydroxide of particle size D 50 114 μm and a sphericity of 82%.
Example 8: unlike example 1, the decomposition temperature in step (3) was 70℃to finally obtain high-purity spherical aluminum hydroxide having a particle size D 50 133 μm and a sphericity of 79%.
Example 9: unlike example 1, the decomposition temperature in step (3) was 100℃to finally obtain high-purity spherical aluminum hydroxide having a particle size D 50 125 μm and a sphericity of 90%.
Example 10: unlike in the case of example 1,repeating the decomposition for 4 times in the step (5) to finally obtain the high-purity spherical aluminum hydroxide with the granularity D 50 117 μm and a sphericity of 86%.
Example 11: unlike example 1, the number of repeated decomposition in step (5) was 10, and finally high-purity spherical aluminum hydroxide of particle size D was obtained 50 137 μm and a sphericity of 90%.
Example 12: unlike example 1, in step (1), sodium aluminate solution Al is added 2 O 3 The concentration is regulated to 70g/L, and finally the high-purity spherical aluminum hydroxide with the granularity D is obtained 50 124 μm and a sphericity of 89%. Example 13: unlike example 1, in step (1), sodium aluminate solution Al is added 2 O 3 The concentration is adjusted to 120g/L, and finally the high-purity spherical aluminum hydroxide with the granularity D is obtained 50 129 μm and a sphericity of 85%. Example 14: the high-purity spherical aluminum hydroxide obtained in example 1 was subjected to hydrothermal treatment at 200℃for 2 hours, filtered, washed, dried, and calcined at 1200℃to obtain high-purity aluminum oxide microspheres having a purity of 99.99% and a sphericity of 92%.
Comparative example 1: (1) High purity sodium aluminate solids (Al 2 O 3 Content of 41%, na 2 30% of O and 99.9% of purity), high-purity water (resistance greater than 13 kiloΩ) is used as solvated slurry, and is adjusted to sodium aluminate solution Al 2 O 3 The concentration is 90g/L, and the sodium aluminate solution is obtained after filtration.
(2) With food-grade high purity CO 2 (purity 99.99%) as raw material, air was three-stage filtered to obtain CO 2 Is mixed by mixing to obtain CO with concentration of 35% 2 And (3) gas.
(3) CO with concentration of 35% 2 Introducing into sodium aluminate solution, performing carbonation neutralization decomposition, stirring for 200r/m at 90deg.C for 1 hr to obtain aluminum hydroxide with particle size D 50 The columnar dispersed aluminum hydroxide particles (see FIG. 2) were 74 μm, not spherical in morphology, and had a sphericity of 0%.
Comparative example 2: unlike example 1, the particle size D of the Bayer process aluminum hydroxide seed crystals is modified in step (3) 50 Is 20 mu m, and finally the irregular aluminum hydroxide aggregate with the granularity D is obtained 50 134 μm and 0% sphericity.
Comparative example 3: (1) High purity sodium aluminate solids (Al 2 O 3 Content of 41%, na 2 30% of O and 99.9% of purity), high-purity water (resistance greater than 13 kiloΩ) is used as solvated slurry, and is adjusted to sodium aluminate solution Al 2 O 3 The concentration is 90g/L, and the sodium aluminate solution is obtained after filtration.
(2) Adding modified Bayer process aluminum hydroxide seed crystals to 1L of sodium aluminate solution according to 300g/L, and obtaining the granularity D 50 80 μm with purity of 99.9%, stirring for 200r/m, decomposing at 90deg.C for 1 hr to obtain aluminum hydroxide with particle size D 50 41um and 0% sphericity.
In all examples and comparative examples, the sphericity was calculated by: testing and characterizing sphericity of particles by using an SEM scanning electron microscope and IPP software; the particle size detector is a Mastersizer 3000 laser particle size detector; the purity detector is an ICP purity detector.
TABLE 1 particle size, sphericity and purity of high purity spherical aluminum hydroxide
TABLE 2 impurity content of high purity spherical alumina in example 14
From the data analysis of examples 1,2 and 3 in table 1, the seed crystal raw material is the most preferred seed crystal of the improved bayer process high-purity aluminum hydroxide, the aluminum alkoxide process high-purity aluminum hydroxide and the carbon precipitation process high-purity aluminum hydroxide, and because of different processes, the improved bayer process high-purity aluminum hydroxide particles have relatively smooth crystal morphology, good sphericity of cyclic decomposition particles, irregular looseness of the aluminum alkoxide process high-purity aluminum hydroxide, poor sphericity of the cyclic decomposition particles, large surface defects of the columnar crystal morphology of the carbon precipitation process high-purity aluminum hydroxide particles, and general sphericity of the cyclic decomposition 6 times of particles.
From the data analysis of examples 1,4 and 5 in Table 1, it can be obtained that the optimal granularity of the seed crystal is 80 μm, and under the same decomposition condition, the granularity of the seed crystal has an effect on sphericity of the decomposed product, the granularity fine decomposition activity is high, and aluminum hydroxide is decomposed and separated out too quickly, which is not beneficial to perfection of sphericity of the particles; the seed crystal has large granularity and low decomposition activity, and is unfavorable for uniform growth of spherical particles.
As can be seen from the data analysis of examples 1,6 and 7 in Table 1, the optimal addition amount of the seed crystal is 300g/L, under the same decomposition condition, the addition amount of the seed crystal has an effect on the sphericity of the product, the supersaturation degree of the decomposition of the seed crystal with low solid content is lower, and the growth of the decomposed spherical aluminum hydroxide is slow; the seed crystals have a high solids content and a fast decomposition, but at the same time under stirring the particle size decreases due to attrition between the particles.
From the data analysis of examples 1,8 and 9 in Table 1, it can be obtained that the decomposition temperature is optimal to 90 ℃, the decomposition temperature has an effect on sphericity of the product, the decomposition speed is high due to the too low temperature, the nucleation amount is large, and the growth of coarse-particle spherical alumina is not favored; too high a temperature, slow decomposition is detrimental to particle growth.
From the data analysis of examples 1, 10 and 11 in table 1, it can be obtained that the optimal cycle number is 6, the number of decomposition cycles has obvious influence on sphericity of the product, the cycle number is low, the surface growth of aluminum hydroxide is imperfect, and sphericity is poor; the circulation times are too high, the abrasion among the aluminum hydroxide particles is serious, the growth of the particles is not facilitated, meanwhile, the production cost is increased due to the too high circulation times, and the economy is poor.
From the data analysis of examples 1, 12, 13 in Table 1, it can be seen that Al of sodium aluminate 2 O 3 The optimal content is 90g/L, and the supersaturation curve of the sodium aluminate solution is known to be Al of the sodium aluminate solution 2 O 3 Too high or too low a concentration will result in increased stability of the solution, which is detrimental to the increase of the decomposition rate and affects the particle growth of the spherical aluminum hydroxide.
As can be seen from the data analysis of example 1 and comparative example 1 in Table 1, the sphericity of aluminum hydroxide obtained by directly carrying out carbonation neutralization decomposition without adding seed crystal was 0%, and carbonation decomposition without adding seed crystal resulted in a large amount of explosive nucleation, rapid growth of granular shape, serious defect of the surface of the granule, and no sphericity.
As can be seen from the data analysis of example 1 and comparative example 2 in Table 1, when the seed particle size is 20 μm and is too small, the sphericity of the obtained aluminum hydroxide is 0%, the seed particle size is too fine, and the activity is too high, which causes a large amount of secondary nucleation, is unfavorable for the growth of particles, the dispersed growth of small particles and the sphericity of the particle morphology is poor.
As shown in fig. 1, SEM image of the spherical aluminum hydroxide obtained in example 1 shows that the aluminum hydroxide obtained in example 1 is spherical with a very smooth and flat surface and a regular shape. Under the condition of the embodiment 1, the matching of the decomposition speed and the nucleation amount with the growth demand of the seed crystal particles is good, the slow spherical growth of the seed crystal particles is satisfied, and the particle size and the morphology of the decomposed product are relatively good.
As can be seen from the data analysis of example 14 in Table 2, the impurity content of the obtained high-purity alumina microsphere is greatly reduced, and the main impurity is Na 2 O, which is caused by the decomposition of the alkali system, na 2 O exists in the form of mainly attached alkali and intergranular alkali, while the hydrothermal method principle is that Na can be effectively removed through lattice rearrangement 2 O, the spherical crystal appearance is not changed, thus laying a foundation for the production of high-purity alumina, and then obtaining the high-purity spherical alumina product by roasting at 1200 ℃.
As shown in fig. 2, the SEM image of the aluminum hydroxide obtained in comparative example 1 shows that the aluminum hydroxide obtained in comparative example 1 has a very uneven surface, is not in the form of regular round spheres, and is columnar and divergent aluminum hydroxide particles.
As can be seen from the analysis of the data of comparative examples 1 and 3, CO was not introduced 2 The aluminum hydroxide obtained without carbonating decomposition is a product with fine particles and irregularities, because CO is not introduced 2 The neutralization decomposition has low nucleation rate, is unfavorable for the growth of particles, and can form small particles with double peak particle size distribution and poor particle morphology under the rapid stirring of 200 r/m.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, as relevant to see a section of the description of method embodiments.
The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are to be included in the scope of the claims of the present application.
Claims (10)
1. The preparation method of the high-purity spherical aluminum hydroxide is characterized by comprising the following steps of:
(1) Adding aluminium hydroxide seed crystal into sodium aluminate solution, introducing CO 2 Performing carbonation neutralization decomposition to obtain aluminum hydroxide;
(2) Adding the obtained aluminum hydroxide as seed crystal into new sodium aluminate solution again, and carrying out carbonation neutralization decomposition;
(3) Repeating the step (2) for 4-10 times, carrying out repeated cyclic carbonation neutralization decomposition, separating and washing to obtain high-purity spherical aluminum hydroxide;
particle size D of the aluminum hydroxide seed crystal 50 The method comprises the following steps: 70-100 mu m.
2. The preparation method according to claim 1, wherein the aluminum hydroxide seed crystal is a high-purity aluminum hydroxide seed crystal with a purity of 99.9%, and the high-purity aluminum hydroxide seed crystal is selected from the group consisting of aluminum alkoxide-process high-purity aluminum hydroxide, modified bayer-process high-purity aluminum hydroxide, carbon-separation-process high-purity aluminum hydroxide, seed-separation-process high-purity aluminum hydroxide, and ammonium-salt-process high-purity aluminum hydroxide.
3. The method of claim 2, wherein the aluminum hydroxide seed crystals are selected from the group consisting of modified bayer process high purity aluminum hydroxide.
4. The method according to claim 3, wherein the amount of the aluminum hydroxide seed crystal added is 200 to 400g/L.
5. The method according to claim 1, wherein the carbonation neutralization decomposition temperature is 70 to 100 ℃ and the time is 1 hour.
6. The method according to claim 1, wherein the sodium aluminate is Al 2 O 3 The content is 70-120 g/L.
7. The method of claim 1, wherein the CO 2 The concentration is 30-40%.
8. The preparation method according to claim 1, wherein the obtained high-purity spherical aluminum hydroxide has a sphericity of 80 to 95%, a particle diameter of 90 to 150 μm and a purity of 99.9%.
9. A high purity alumina microsphere prepared according to any one of claims 1-8, wherein the high purity alumina microsphere has a purity of >99.99% and a sphericity of >90%;
the preparation method of the high-purity alumina microsphere comprises the following steps: and carrying out hydrothermal treatment on the high-purity spherical aluminum hydroxide, and roasting to obtain the high-purity aluminum oxide microspheres.
10. A high purity alumina microsphere prepared according to claim 9, which is applied to the fields of high heat conduction, grinding, catalysis and the like.
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