SI9300649A - Procedure for the preparation of aluminium oxide particles, therefrom produced aluminium oxide powder and its use - Google Patents
Procedure for the preparation of aluminium oxide particles, therefrom produced aluminium oxide powder and its use Download PDFInfo
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- SI9300649A SI9300649A SI9300649A SI9300649A SI9300649A SI 9300649 A SI9300649 A SI 9300649A SI 9300649 A SI9300649 A SI 9300649A SI 9300649 A SI9300649 A SI 9300649A SI 9300649 A SI9300649 A SI 9300649A
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- aluminum
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- 239000002245 particle Substances 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 30
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims abstract description 22
- 239000000843 powder Substances 0.000 title claims abstract description 10
- 238000002360 preparation method Methods 0.000 title abstract description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 27
- 229910052782 aluminium Inorganic materials 0.000 claims description 25
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 25
- 239000007789 gas Substances 0.000 claims description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 11
- 229910052799 carbon Inorganic materials 0.000 claims description 9
- 238000007254 oxidation reaction Methods 0.000 claims description 9
- -1 aluminum carbides Chemical class 0.000 claims description 8
- 230000003647 oxidation Effects 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 6
- 239000003638 chemical reducing agent Substances 0.000 claims description 5
- 238000010891 electric arc Methods 0.000 claims description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 150000001247 metal acetylides Chemical class 0.000 claims description 3
- 229910052760 oxygen Inorganic materials 0.000 claims description 3
- 239000001301 oxygen Substances 0.000 claims description 3
- 239000011230 binding agent Substances 0.000 claims description 2
- 239000003054 catalyst Substances 0.000 claims description 2
- 229910010293 ceramic material Inorganic materials 0.000 claims description 2
- 150000001875 compounds Chemical class 0.000 claims description 2
- 239000000945 filler Substances 0.000 claims description 2
- 238000003780 insertion Methods 0.000 claims description 2
- 230000037431 insertion Effects 0.000 claims description 2
- 238000005498 polishing Methods 0.000 claims description 2
- 239000000443 aerosol Substances 0.000 claims 1
- 230000001590 oxidative effect Effects 0.000 claims 1
- 238000000926 separation method Methods 0.000 claims 1
- 239000000203 mixture Substances 0.000 description 5
- 238000005245 sintering Methods 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical group Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000012798 spherical particle Substances 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- CAVCGVPGBKGDTG-UHFFFAOYSA-N alumanylidynemethyl(alumanylidynemethylalumanylidenemethylidene)alumane Chemical compound [Al]#C[Al]=C=[Al]C#[Al] CAVCGVPGBKGDTG-UHFFFAOYSA-N 0.000 description 1
- LCQXXBOSCBRNNT-UHFFFAOYSA-K ammonium aluminium sulfate Chemical compound [NH4+].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O LCQXXBOSCBRNNT-UHFFFAOYSA-K 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000009970 fire resistant effect Effects 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 235000012054 meals Nutrition 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
- C09K3/14—Anti-slip materials; Abrasives
- C09K3/1409—Abrasive particles per se
- C09K3/1418—Abrasive particles per se obtained by division of a mass agglomerated by sintering
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/02—Boron or aluminium; Oxides or hydroxides thereof
- B01J21/04—Alumina
-
- 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
- C01F7/30—Preparation of aluminium oxide or hydroxide by thermal decomposition or by hydrolysis or oxidation of aluminium compounds
- C01F7/302—Hydrolysis or oxidation of gaseous aluminium compounds in the gaseous phase
-
- 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
- C01F7/42—Preparation of aluminium oxide or hydroxide from metallic aluminium, e.g. by oxidation
- C01F7/422—Preparation of aluminium oxide or hydroxide from metallic aluminium, e.g. by oxidation by oxidation with a gaseous oxidator at a high temperature
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/10—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
- C04B35/111—Fine ceramics
-
- B01J35/613—
-
- 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
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- 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
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 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
- C01P2006/10—Solid density
-
- 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
- C01P2006/12—Surface area
-
- 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
Description
Treibacher Chemische Werke AGTreibacher Chemische Werke AG
Postopek za pripravo delcev aluminijevega oksida, po tem postopku pripravljeni aluminijev oksid v prahu kot tudi njegova uporabaProcess for the preparation of aluminum oxide particles, prepared alumina powder and the use thereof
Izum se nanaša na postopek za pripravo sintrno aktivnih, v največji meri sferičnih delcev aluminijevega oksida s srednjim premerom delcev < 1,0 μαι, na po tem postopku pripravljeni aluminijev oksid v prahu kot tudi na njegovo uporabo.The invention relates to a process for the preparation of sinter-active, largely spherical aluminum oxide particles with a mean particle diameter of <1.0 μαι, to the powder-prepared aluminum oxide as well as to its use.
Aluminijev oksid v prahu uporabljajo kot pigmente, brusna in polirna sredstva, v nepregornih ah v ognju obstojnih izdelkih, v keramiki, kot material za katalizatorje ali kot polnilo kot tudi za premaze.Aluminum oxide powder is used as pigments, abrasives and polishing agents, in refractory fire resistant products, in ceramics, as catalyst material or as filler as well as coatings.
Odločilni za tehnično uporabo aluminijevega oksida so njegova kemična obstojnost, dobre mehanske trdnosti, zlasti ugodne obrabne lastnosti, velika električna upornost in dobra temperaturna obstojnost. Poleg tega aluminijev oksid ni strupen.Crucial to the technical use of aluminum oxide are its chemical resistance, good mechanical strength, especially its favorable wear properties, high electrical resistance and good temperature resistance. In addition, aluminum oxide is not toxic.
Za pripravo zelo kakovostnih keramičnih, zlasti nepregornih izdelkov, se zahtevajo predvsem tele lastnosti:For the production of high quality ceramic, especially non-refractory products, the following properties are required in particular:
- visoka sintma aktivnost (zlasti zaradi majhnih velikosti zrn),- high synthetic activity (especially due to the small grain size),
- minimiranje nečistot, ki zavirajo proces sintranja ali pospešujejo nezaželeno rast zm,- minimizing impurities that inhibit the sintering process or promote unwanted growth of the sn,
- kar najmanjše vsebnosti spremljajočih snovi, ki tvorijo talinske faze,- the minimum content of the accompanying substances forming the melt phase,
- dobra obdelovalnost (stisljivost),- good workability (compressibility),
- velika gostota materiala v surovem stanju.- high density of the material in its raw state.
Za dosego velikih trdnosti materiala v surovem stanju (gostot materiala v surovem stanju) je potrebna tudi majhna poroznost posameznih delcev (prašnih delcev).In order to achieve high strengths of the raw material (density of the raw material), a small porosity of the individual particles (dust particles) is also required.
Znana je vrsta termičnih, mokro kemičnih, mehanskih in fizikalnih postopkov za pripravo sintmo aktivnih, mikrokristaliničnih delcev in prahov A12O3.A number of thermal, wet chemical, mechanical and physical processes are known for the preparation of synthetically active, microcrystalline particles and A1 2 O 3 powders.
Sem spadajo termični razkroj in temu sledeča kalcinacija očiščenega galuna (amonijevega aluminijevega sulfata) ali termični razkroj aluminijevega klorida po t.i. postopku razpršilnega praženja. Slabe strani pri tovrstnih termičnih presnovah aluminijevih soli so visoka cena za ustrezne naprave in ostanki soli, ki preostanejo v oksidu, ki lahko prispevajo k povečani rasti zm med procesom sintranja.These include thermal decomposition followed by calcination of purified gallun (ammonium aluminum sulphate) or thermal decomposition of aluminum chloride by so-called. the spray roasting process. The disadvantages of this kind of thermal digestion of aluminum salts are the high cost of suitable devices and residues of the salt that remain in the oxide, which can contribute to increased growth of the mixture during the sintering process.
Za pripravo aluminijevega oksida v obliki finih delcev je tudi znano mletje glinice, pripravljene po ti. Bayerjevem postopku. Vendar je to fino mletje zelo drago in tem dolgotrajnejše, čim fineje je treba zmleti material tako, da se da delce pod 1 μτη - če sploh - pripraviti le s skrajnim tehničnim trudom. Morfologija tako pripravljenih prašnih delcev je razen tega iverasto-zmasta. To lahko povzroči pomanjkljivosti pri reoloških lastnostih.For the preparation of alumina in the form of fine particles, it is also known to grind alumina prepared by so-called. Bayer's process. However, this fine grinding is very expensive and the longer it takes, the finer the grinding material, so that particles below 1 μτη - if any - can only be prepared with extreme technical effort. In addition, the morphology of the particulates thus prepared is chipboard-like. This can lead to defects in rheological properties.
Iz US-A-4,818,515 je znana priprava sferičnih delcev A12O3 po postopku, pri katerem obdelajo aluminijev oksid, ki vsebuje vodo, v posebni, večstopenjski termični obdelavi. Postopek zahteva izhodno snov, ki se jo da zaradi potrebne čistote pripraviti le ob znatnih stroških.US-A-4,818,515 discloses the preparation of A1 2 O 3 spherical particles by a process in which water-containing aluminum oxide is treated in a special, multi-stage thermal treatment. The process requires a starting material that can only be prepared at considerable cost because of the required purity.
Končno se da s hidrolizo aluminijevih alkoksidov pripraviti kalcinate v obliki drobnih delcev, ki pa kažejo po stopnji kalciniranja deloma znatno mikroporoznost, kar vodi v sledečem procesu sintranja do ustreznega (nezaželenega) krčenja.Finally, the hydrolysis of aluminum alkoxides allows the preparation of calcinates in the form of fine particles, which in part show a significant microporosity after calcination, which in the subsequent sintering process leads to an appropriate (undesirable) shrinkage.
Zato se navedeni postopki iz tehničnih in ekonomskih razlogov niso uveljavili za mnoge masovne uporabe.Therefore, for technical and economic reasons, the above procedures have not been established for many mass applications.
Zato je pričujočemu izumu za osnovo naloga ponuditi postopek, ki omogoča na stroškovno sorazmerno ugoden način pripravo zelo finih delcev aluminijevega oksida v submikrometerskem območju (< 1,0 μηϊ), pri čemer je cilj v največji meri sferična oblika zrna, majhna poroznost in s tem dobre lastnosti pri zgoščevanju in sintranju, da bi omogočili uporabo za v začetku navedene smotre oz. da bi jo optimirali.It is therefore an object of the present invention to provide a process that enables the production of very fine alumina particles in the submichrometer range (<1.0 μηϊ) in a cost-effective way, with the objective being largely spherical grain shape, low porosity, and thus good densification and sintering properties to allow for the use of the aforementioned purpose. to optimize it.
Ta smoter dosežemo s postopkom v začetku omenjene vrste, ki se odlikuje z naslednjimi stopnjami:This purpose is achieved by the procedure at the beginning of the mentioned species, characterized by the following stages:
- vnašanje nosilca aluminija, kot Al ali A12O3, v pečni agregat,- insertion of an aluminum carrier, such as Al or A1 2 O 3 , into the furnace,
- segrevanje nosilca aluminija,- heating of the aluminum carrier,
- redukcija nosilca aluminija, v kolikor ga ne vnesemo kot kovinski aluminij, do kovinskega aluminija in/ali aluminijevih karbidov (vključno aluminijevih oksikarbidov),- reduction of the aluminum carrier, unless introduced as metallic aluminum, to metallic aluminum and / or aluminum carbides (including aluminum oxycarbides),
- zvišanje pečne temperature na vrednost, pri kateri se kovinski aluminij oz. aluminijevi karbidi uparijo,- raising the furnace temperature to the value at which metallic aluminum or aluminum carbides evaporate,
- temu sledeča oksidacija kovinskega aluminija oz. njegovih karbidov v aluminijev oksid v plinskem toku in- the next oxidation of metallic aluminum or. of its carbides to aluminum oxide in a gas stream and
- uvajanje plinskega toka v filter, pri čemerintroducing a gas stream into the filter,
- naravnamo temperaturo, atmosfero in zadrževalni čas delcev aluminijevega oksida v plinskem toku ustrezno zaželeni velikosti delcev.- adjust the temperature, atmosphere and residence time of the aluminum oxide particles in the gas stream to suit the desired particle size.
Če izhajamo npr. iz aluminijevega oksida v kosih, ga torej najprej reduciramo v kovinski aluminij in/ali aluminijeve karbide, te nato oz. vzporedno uparimo in končno na primeren način ponovno oksidiramo, predno v filtru ločimo sekundarno nastale delce aluminijevega oksida.If we derive e.g. of aluminum oxide in pieces, then it is first reduced to metallic aluminum and / or aluminum carbides, and then respectively. Evaporate in parallel and finally oxidize appropriately before separating the secondary alumina particles in the filter.
Pri tem je za dosego finosti delcev aluminijevega oksida, kot je definirana z nalogo, popolnoma bistveno, da vodimo delce A12O3, ki jih vodimo v plinskem toku, v priključeni filter v plinskem toku. Čim krajši je zadrževalni čas delcev A1?O3 v plinskem toku, tem manjša je velikost delcev, ki jo lahko sekundarno uravnavamo tudi s temperaturo in (oksidimo) atmosfero plinskega toka.In order to achieve the fineness of the aluminum oxide particles, as defined by the assignment, it is absolutely essential to guide the A1 2 O 3 particles, which are guided in the gas stream, to the connected filter in the gas stream. The shorter the dwell time of the A1 particles ? About 3 in the gas stream, the smaller the particle size, which can also be controlled secondarily by the temperature and (oxidize) atmosphere of the gas stream.
Da bi dosegli kar najfinejše delce A12O3, je torej filter priključen neposredno za spredaj opisano oksidacijsko stopnjo.In order to obtain the finest A1 2 O 3 particles, the filter is therefore connected directly to the oxidation step described above.
Kot pečni agregat se je kot posebno ugodna izkazala električna obločna peč. Ta obratuje po eni izvedbeni obliki izuma z gostotami toka med 10 in 50 A/cm2, prednostno v območju med 15 in 30 A/cm2.An electric arc furnace proved particularly favorable as a furnace unit. It operates according to one embodiment of the invention with a current density between 10 and 50 A / cm 2 , preferably in the range of 15 to 30 A / cm 2 .
Za zvišanje učinkovite storilnosti uparevanja se je pokazal kot ugoden dodatek redukcijskega sredstva (kot ogljika) pri reakciji redukcije aluminijevega oksida v aluminij, aluminijev karbid ali aluminijev oksikarbid. Tudi spojine, ki oddajajo ogljik, lahko uporabimo v tem smislu.To enhance effective evaporation performance, it has proven to be a favorable addition of a reducing agent (such as carbon) in the reaction of reducing aluminum oxide to aluminum, aluminum carbide or aluminum oxycarbide. Carbon-emitting compounds can also be used in this sense.
Neposredno sledečo oksidacijo aluminija v obliki pare in/ali kondenziranih aluminijevih delcev lahko pospešimo z zunanjim dovajanjem kisika. S tem je omogočeno, da pri le kratkem zadrževalnem času delcev v oksidacijski stopnji le-te takoj nato ločimo v primernem filtru, npr. filtrski vreči.The subsequent oxidation of aluminum in the form of steam and / or condensed aluminum particles can be accelerated by the external oxygen supply. This makes it possible to separate the particles in the oxidation stage immediately after a short residence time in a suitable filter, e.g. filter bag.
Alternativno lahko izvedemo oksidacijsko stopnjo tako, da vodimo delce aluminija v odsek peči, v katerem je oksidima atmosfera.Alternatively, the oxidation step can be carried out by guiding the aluminum particles to the furnace section in which the oxides are atmosphere.
Z opisanim postopkom se da pripraviti sintmo aktivne sferične delce aluminijevega oksida z gostoto do 3,97 g/cm3 in specifično površino med 0,5 in 60 m2/g.By the procedure described above, it is possible to prepare synthetically active spherical alumina particles with a density of up to 3.97 g / cm 3 and a specific surface area between 0.5 and 60 m 2 / g.
Postopek omogoča tvorbo delcev aluminijevega oksida s srednjo velikostjo delcev razločno pod 1 /im, z ustreznim naravnanjem parametrov postopka, kot so temperatura, atmosfera in zadrževalni čas delcev A12O3 v plinskem toku, celo tja do 0,10 μτη.The process allows the formation of aluminum oxide particles with a mean particle size clearly below 1 / m, with appropriate adjustment of the process parameters such as temperature, atmosphere and residence time of A1 2 O 3 particles in the gas stream, even up to 0.10 μτη.
Posebna ugodnost je v tem, da kažejo po opisanem postopku pripravljeni delci A12O3 skoraj idealno sferično (kroglasto) konfiguracijo tako, da se da material posebno ugodno uporabiti npr. za brusna in polima sredstva ali v nepregomih keramičnih materialih (tam tudi kot vezivo oz. vezivna komponenta). Kroglasta oblika je odločilno odgovorna za to, da delci prispevajo k izvrstnim reološkim lastnostim ustreznih sistemov.It is a particular advantage that the prepared A1 2 O 3 particles exhibit an almost ideally spherical (spherical) configuration according to the procedure described in such a way that the material can be particularly advantageously used e.g. for abrasive and polymers or in non-stick ceramic materials (also there as a binder or bonding component). The spherical shape is decisively responsible for the particles contributing to the excellent rheological properties of the respective systems.
Pri uporabi električne obločne peči se lahko nahaja vložek brez težav v obliki kosov. Pri tem je uparjevalni učinek nastalega obloka odvisen od njegove vsebnosti energije in lokalne temperature obloka. Pri gostotah toka v območju od 10 do 50 A/cm2 leži uparjevalni učinek v območju med 40 in 100 g Al2O3/kwh.When using an electric arc furnace, the insert can easily be in the form of pieces. The evaporative effect of the resulting arc depends on its energy content and the local temperature of the arc. For current densities in the range of 10 to 50 A / cm 2, the evaporative effect lies in the range of 40 to 100 g Al 2 O 3 / kwh.
Sestava delcev A12O3, dobljenih po postopku, je odvisna od uporabljene surovine, ki vsebuje aluminij (nosilca aluminija) in uporabljenega redukcijskega sredstva. Če vsebuje surovina in/ali redukcijsko sredstvo alkalijske in/ali zemeljskoalkalijske okside, SiO2, železov oksid ali podobno, najdemo te nečistote skoraj kvantitativno spet v končnem produktu. Pri uporabi ogljika kot redukcijskega sredstva, deloma pa tudi zaradi ogljika iz elektrod peči, se sproste majhne množine ogljika in tvorijo se karbidi ali oksikarbidi. V končnem produktu so takrat, v kolikor ponovna oksidacija ne poteče popolnoma, možne vsebnosti ogljika do okoli 0,5 mas. %, ki jih po potrebi lahko še nadalje reduciramo z naknadno termično obdelavo (npr. žarilno obdelavo).The composition of the A1 2 O 3 particles obtained by the process depends on the feedstock containing aluminum (the aluminum carrier) and the reducing agent used. If the raw material and / or reducing agent contains alkali and / or alkaline earth oxides, SiO 2 , ferric oxide or the like, these impurities are found almost quantitatively again in the final product. When carbon is used as a reducing agent, and partly because of carbon from the furnace electrodes, small amounts of carbon are released and carbides or oxycarbides are formed. In the final product, if the re-oxidation does not proceed completely, carbon contents of up to about 0.5 wt. % which can be further reduced by heat treatment (eg incandescent) if necessary.
Izum sedaj bliže opisujemo z izvedbenim primerom:The invention is now more closely described by way of example:
V električno obločno peč z grafitnimi elektrodami damo mešanico iz 85 mas. delov aluminijevega oksida v kosih in 15 mas. delov grafitnega zdroba. Po vžigu obloka se sprva tvori talina iz aluminijevega oksida, A14O4C in Al4C3, ki je ugodna kot zaščitna plast za oblogo dna peči (ki sestoji tu iz ogljikovih opek). Zmogljivost obloka je v območju med 150 in 180 kVA. Gostota toka znaša med 16 in 23 A/cm2.A mixture of 85% by weight was placed in an electric arc furnace with graphite electrodes. pieces of aluminum oxide in pieces and 15 wt. parts of graphite meal. Upon ignition of the arc, the aluminum oxide melt, A1 4 O 4 C and Al 4 C 3 , is initially formed, which is advantageous as a protective layer for the furnace bottom lining (consisting here of carbon bricks). The capacity of the arc is between 150 and 180 kVA. The current density is between 16 and 23 A / cm 2 .
Kasneje pride do uparjenja kosovnega izhodnega materiala ob tvorbi kovinskega aluminija in aluminijevih karbidov, ki se potem v atmosferi ali z dovajanjem kisika ponovno oksidirajo v delce A12O3, predno le-te uvedemo v tkaninski filter, kjer se več kot 99 mas. %-no izločijo. Povprečna velikost dobljenih, pretežno sferičnih delcev aluminijevega oksida v prahu, znaša 0,2 μ,πι. Gostota materiala znaša 3,8 g/cm3. Specifična površina znaša 9,8 m2/g.Subsequently, the bulky starting material is evaporated upon the formation of metallic aluminum and aluminum carbides, which are then re-oxidized in the atmosphere or by oxygen supply to A1 2 O 3 particles before being introduced into the fabric filter, where more than 99 wt. % eliminated. The average size of the obtained mainly spherical particles of alumina powder is 0.2 μ, πι. The material density is 3.8 g / cm 3 . The specific surface area is 9.8 m 2 / g.
Pri sestavi izhodnega materiala A12O3 z 0,03 mas. % Na2O + K^O 0,014 mas. % Fe2O3 0,03 mas. % MgO 0,03 mas. % SiO2 preostanek A12O3 dobimo A12O3 v prahu s tole sestavo delcev: 0,037 mas. % Na2O + K2OIn the composition of the starting material A1 2 O 3 with 0.03 wt. % At 2 O + K ^ O 0.014 wt. % Fe 2 O 3 0.03 wt. % MgO 0.03 wt. % SiO 2 the residue A1 2 O 3 gives A1 2 O 3 powder with the following particle composition: 0.037 wt. % At 2 O + K 2 O
Zvišanje nečistot izvira pri tem iz deleža pepela grafita, uporabljenega za redukcijo, kot tudi iz elektrod peči.The increase in impurities stems from the ash content of the graphite used for the reduction as well as from the furnace electrodes.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4241625A DE4241625C1 (en) | 1992-12-10 | 1992-12-10 | Process for the production of sinter-active, largely spherical aluminum oxide and its use |
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| SI9300649A true SI9300649A (en) | 1994-06-30 |
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| SI9300649A SI9300649A (en) | 1992-12-10 | 1993-12-10 | Procedure for the preparation of aluminium oxide particles, therefrom produced aluminium oxide powder and its use |
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| EP (1) | EP0601453A3 (en) |
| JP (1) | JPH07309618A (en) |
| CA (1) | CA2110961A1 (en) |
| CZ (1) | CZ260493A3 (en) |
| DE (1) | DE4241625C1 (en) |
| HU (1) | HUT68748A (en) |
| PL (1) | PL301393A1 (en) |
| SI (1) | SI9300649A (en) |
| SK (1) | SK138493A3 (en) |
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| DE19520614C1 (en) * | 1995-06-06 | 1996-11-07 | Starck H C Gmbh Co Kg | Microcrystalline sintered abrasive grains based on a-AI¶2¶O¶3¶ with high wear resistance, process for its production and its use |
| DE19605556C1 (en) * | 1996-02-15 | 1997-09-11 | Vaw Silizium Gmbh | Reactive spherical metal oxide powder particles |
| US5856254A (en) * | 1996-02-15 | 1999-01-05 | Vaw Silizium Gmbh | Spherical metal-oxide powder particles and process for their manufacture |
| KR19990023544A (en) * | 1997-08-19 | 1999-03-25 | 마쯔모또 에이찌 | Aqueous dispersion of inorganic particles and preparation method thereof |
| US6391072B1 (en) * | 2000-05-04 | 2002-05-21 | Saint-Gobain Industrial Ceramics, Inc. | Abrasive grain |
| CN101538119B (en) | 2001-08-02 | 2013-07-24 | 3M创新有限公司 | Method for manufacturing article made of glasses and glass ceramic article prepared therefor |
| CN1649802B (en) * | 2001-08-02 | 2012-02-01 | 3M创新有限公司 | Ceramic materials, abrasive particles, abrasive articles, and methods of making and using the same |
| US7563293B2 (en) | 2001-08-02 | 2009-07-21 | 3M Innovative Properties Company | Al2O3-rare earth oxide-ZrO2/HfO2 materials, and methods of making and using the same |
| US8056370B2 (en) | 2002-08-02 | 2011-11-15 | 3M Innovative Properties Company | Method of making amorphous and ceramics via melt spinning |
| US7811496B2 (en) | 2003-02-05 | 2010-10-12 | 3M Innovative Properties Company | Methods of making ceramic particles |
| US7292766B2 (en) | 2003-04-28 | 2007-11-06 | 3M Innovative Properties Company | Use of glasses containing rare earth oxide, alumina, and zirconia and dopant in optical waveguides |
| CN101829607B (en) * | 2010-05-17 | 2012-04-18 | 昆明珀玺金属材料有限公司 | Method for preparing catalyst carrier Al2O3 powder by activating and hydrolyzing metallic aluminium under ultrasound-electric field coupling |
| NO337267B1 (en) * | 2014-02-10 | 2016-02-29 | Elkem As | Process for the production of alumina particles |
| CN106062122B (en) | 2014-02-27 | 2018-12-07 | 3M创新有限公司 | Abrasive grain, abrasive product and its preparation and application |
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| NL82125C (en) * | 1951-12-19 | |||
| NL108800C (en) * | 1954-05-28 | 1900-01-01 | ||
| SU967029A1 (en) * | 1965-11-20 | 1983-08-30 | Институт Химической Физики Ан Ссср | Process for preparing metal oxides |
| IT1020754B (en) * | 1973-09-10 | 1977-12-30 | Electricity Council | PROCEDURE AND EQUIPMENT FOR THE PRODUCTION OF ULTRAFINE PARTICLES OF OXIDIC CERAMIC MATERIALS |
| BR7502067A (en) * | 1974-04-26 | 1976-03-03 | J Chevalley | PROCESS AND INSTALLATION THAT ALLOW THE TRANSPORT AND REVALUATION OF ENERGY FORMS LOCALLY AVAILABLE |
| IT1184114B (en) * | 1985-01-18 | 1987-10-22 | Montedison Spa | ALFA ALUMINATES IN THE FORM OF SPHERICAL PARTICLES, NOT AGGREGATED, WITH RESTRIBUTION GRANULOMETRIC RESTRICTED AND OF LESS THAN 2 MICRONS, AND PROCESS FOR ITS PREPARATION |
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- 1992-12-10 DE DE4241625A patent/DE4241625C1/en not_active Revoked
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- 1993-12-01 EP EP19930119343 patent/EP0601453A3/en not_active Withdrawn
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- 1993-12-08 CA CA002110961A patent/CA2110961A1/en not_active Abandoned
- 1993-12-09 PL PL93301393A patent/PL301393A1/en unknown
- 1993-12-09 JP JP5344621A patent/JPH07309618A/en active Pending
- 1993-12-10 HU HU9303535A patent/HUT68748A/en unknown
- 1993-12-10 SI SI9300649A patent/SI9300649A/en unknown
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| Publication number | Publication date |
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| HU9303535D0 (en) | 1994-04-28 |
| EP0601453A2 (en) | 1994-06-15 |
| JPH07309618A (en) | 1995-11-28 |
| CZ260493A3 (en) | 1994-08-17 |
| PL301393A1 (en) | 1994-06-13 |
| HUT68748A (en) | 1995-04-27 |
| SK138493A3 (en) | 1994-07-06 |
| DE4241625C1 (en) | 1994-06-30 |
| EP0601453A3 (en) | 1994-12-07 |
| CA2110961A1 (en) | 1994-06-11 |
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