CN1182037C - Prepn of high-purity alumina - Google Patents

Prepn of high-purity alumina Download PDF

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CN1182037C
CN1182037C CNB021089914A CN02108991A CN1182037C CN 1182037 C CN1182037 C CN 1182037C CN B021089914 A CNB021089914 A CN B021089914A CN 02108991 A CN02108991 A CN 02108991A CN 1182037 C CN1182037 C CN 1182037C
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choline
aluminium
high purity
purity
controlled
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CN1374252A (en
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骆树立
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Hebei Hengbo New Materials Polytron Technologies Inc
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Pengdaxin Material Science & Technology Co Ltd Hebei Prov
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Abstract

The present invention relates to a method for preparing high purity alumina, which is mainly characterized in that choline hydroxide reacts with high purity metallic aluminium to generate choline aluminum, the choline aluminum is hydrolyzed to generate aluminium hydroxide and choline hydroxide, and the aluminium hydroxide is filtered by washing, precipitated, calcined, ground, etc. to obtain high purity alpha-alumina. The method has the advantages of high product purity, good quality, low requirement for technological conditions, no pollution, low cost, etc. The high purity alumina prepared by the method is particularly suitable for being used in the fields of high voltage sodium lamp tubes, rare earth luminescent material, high grade grinding material, fine ceramics, etc.

Description

The preparation method of high purity aluminium oxide
Technical field:
The present invention relates to the highly purified metallic aluminium of a kind of usefulness and prepare highly purified method of alumina as raw material through chemical reaction.
Background technology:
High purity aluminium oxide is mainly used in rare-earth luminescent material, high-pressure sodium fluorescent tube and other is such as extraordinary aluminum oxide application scenarios such as abrasive material, catalyzer and structural ceramicss, metals content impurity seldom (less than 0.01%) in the high purity aluminium oxide, sulfide and muriate also are deleterious.
The method that prior art is produced high purity aluminium oxide has following several:
One is the rinsing of Bayer process aluminum oxide, contain excessive sodium and silicon in Bayer process aluminum oxide and the aluminium hydroxide, the concentration of these impurity can reduce by the conditioned disjunction rinsing incinerating aluminum oxide of separating out that changes aluminium hydroxide, but these technology both expensive are unreliable to controlling required impurity level.
Chinese patent literature 95103368.9 and 95105843.6 relates to a kind of processing method of producing aluminum oxide and alumina powder with salting-out process, and its main drawback is that purity is lower, and environmental pollution is serious.
Chinese patent literature 93110316.9 relates to a kind of high-purity ultra-fine alumina production technique and device, and the tschermigite decomposition makes γ-Al 2O 3, phase inversion is α-Al then 2O 3, calcining produces the corrodibility acid gas, has economy and environmental problem.
Select high pure metal aluminium to have very big advantage, because can on technical scale, a large amount of cheapnesss produce 99.99% aluminium now as the starting materials of producing aluminum oxide.
Preparing method of alumina from metallic aluminium has multiple, a kind of is the hydrothermal oxidization metallic aluminium, metallic aluminium is (350-400 degree) and the following aluminum oxide that generates of high pressure (68-308 normal atmosphere) at high temperature, and these conditions need high-pressure reaction vessel, make the metal complete reaction need long time.
CN1079718 puts into the activation of 0.5% mercuric chloride solution with fine aluminium sheet or bits and takes out after one minute, puts into the distilled water hydrolysis again, at last with high-temperature heat treatment come the size of controlled oxidation aluminium nano particle with mutually.Mercury is the deadly defect of this method to the infringement of environment and human body.
Metallic aluminium generates aluminium alcoholates with the alcohol reaction under non-water condition, aluminium alcoholates and water reaction generate oxyhydroxide, Chinese patent literature 91111373.8 and Chinese patent literature 97103240.8 disclose and have a kind ofly prepared the method for super-microfine high pure alumina by low-carbon (LC) aluminium alcoholates hydrolysis reaction, can obtain purity greater than 99.99%, even-grained ultra micro fineness pure alumina product.The stock of the alcohol that this arts demand is relatively large and Distallation systm, what catch fire during operation and explode is dangerous big, simultaneously the cost height of product.
CN87106229 discloses a kind of method of producing high-purity alpha-alumina, this method comprises the oxidation reaction product that is formed by aluminium mother metal and oxygen-containing gas oxidant, the direct oxidation fine aluminium has only when aluminium powder very thin (74 μ) just possible, metallic aluminium and oxygen or oxidant reaction are very fast, so the oxidized hot institute of aluminum oxide fusion, the oxidation that this means aluminium powder both had been difficult to control, and potential danger is arranged again.
Summary of the invention:
The purpose of this invention is to provide the preparation method that a kind of quality product height, processing condition require low, non-environmental-pollution, high purity aluminium oxide that cost is low.
The object of the present invention is achieved like this: a kind of preparation method of high purity aluminium oxide, and it is characterized in that adopting following processing method to obtain high-purity αYang Hualv: i) raw material: purity is 99.996% refined aluminium; The choline that adopts reinforcing yin essence ion exchange resin that choline chloride 60 is transformed and generate; The reaction vessel that ii) adopts polyvinyl chloride, tetrafluoroethylene or the polypropylene plastics of anti-highly basic to make, temperature is controlled by built-in pipeline by circulating water and hot water, is reflected to stir the realization down of pressurized air bubbling; Iii) temperature of reaction is controlled at 20-80 ℃, and choline concentration is controlled at 0.1-2.0M, and the aluminium hydroxide of acquisition is at 110 ℃ of air dryings; Iv) refined aluminium, water, choline react under above-mentioned processing condition, judge speed of response by monitoring hydrogen effusion speed, and be very low or when stopping when speed of response, removes slurry, carries out solid-liquid separation, periodically adds refined aluminium, removes slurry; Aluminium hydroxide obtains dry powder by filtration, spraying drying, choline loops back reaction vessel, dried aluminium hydroxide is placed in kiln in the high purity aluminium oxide crucible and calcines, and the aluminium hydroxide after the calcining is pulverized at ball mill with the high purity aluminium oxide ball and obtained αYang Hualv, and purity can reach 99.99%.
Purpose of the present invention can also realize like this: temperature of reaction is controlled at 75 ℃, and choline concentration is controlled at 0.5M.
The present invention has following advantage: 1) product purity height, quality is good.The finished product aluminum oxide purity can reach 99.99%; 2) processing condition with gentleness are operated in the reactor that band stirs, and environmentally friendly, toxicological harmless is pollution-free; 3) cost is lower, and is attractive economically.
Embodiment:
The present invention is circulating reaction a---process of separating out that replaces the sodium hydroxide in the Bayer technology that everybody is familiar with choline.With the processing condition operation of gentleness, environmentally friendly, attractive economically in the reaction vessel that band stirs.
Indirectly produce aluminum oxide or make aluminium indirectly and water or the reaction of other water-soluble oxidizers generate aluminium hydroxide, calcining then, this method is than direct oxidation method controls reaction speed (and the amount of bringing into of controlling product impurity) preferably.
Basic metal and four closes ammonium hydroxide (molecular formula [(CH 3) 3N (CH 2CH 2OH)] OH, be abbreviated as ROH) reaction can easily metallic aluminium be converted into aluminium hydroxide and not produce any pollution, particularly four close ammonium hydroxide and have four organic groups to be connected with covalent linkage with nitrogen-atoms in the amine, ROH is a highly basic, on intensity with alkali metal hydroxide seemingly, this and organic amine (as an amine, diamines, triamine) are that weakly alkaline conclusion is completely contradicted, the intensity of ROH derives from being connected of four organic groups and nitrogen-atoms, the organic group of covalent linkage has been avoided contact (as the amine) of nitrogen-atoms with water, forces OH -Ionization fully, choline is operated in a looping fashion among the present invention, and Recycle design makes the consumption of reagent reach minimum, and the amount of by-products that produces during calcining is minimum.
It is that the molecular structural formula of choline is because its low toxicity reaches suitability preferably that choline is used for the present invention:
High purity aluminium oxide preparation process chemical equation of the present invention is:
R wherein +OH -Be choline molecular formula [(CH 3) 3N (CH 2CH 2OH)] OH's writes a Chinese character in simplified form.
The present invention adopts 99.996% refined aluminium as raw material, and its foreign metal is analyzed as table 1.
Choline can utilize choline chloride 60 is prepared by strong basic ion exchange resin, choline concentration is controlled at 0.1-2.0M (doing the standard titration with hydrochloric acid), choline chloride 60 is incomplete to the conversion of choline, choline alkalescence is stronger than ammonia and amine, but a little less than sodium hydroxide, its toxicity is because its corrodibility and strong basicity.
Reaction vessel is made by plastics of anti-highly basic such as polyvinyl chloride, tetrafluoroethylene, polypropylene, stirs the pressurized air bubbling and realizes, temperature is controlled by built-in pipeline by circulating water and hot water, and the system architecture material is to keeping product purity very important.Speed of response is judged that by the speed that monitors the hydrogen effusion reactant is by vacuum filtration, sedimentation, press filtration, and a large amount of unreacted metal were restored in this step, and aluminium hydroxide is at 110 ℃ of air dryings.
During mass production, an amount of metallic aluminium, water, acetylcholine response are very low or stop to speed of response, remove slurry, carry out solid-liquid separation, periodically add metallic aluminium, remove slurry.Aluminium hydroxide obtains dry powder by filtration, spraying drying, and choline loops back reaction vessel, and dry back aluminium hydroxide is placed in kiln in the high purity aluminium oxide crucible to be calcined, and the aluminium hydroxide after the calcining is pulverized in ball mill with the high purity aluminium oxide ball.
The alkalescence of choline determines in the specific conductivity under the differing temps that by aqueous choline base solution under the measurement differing temps specific conductivity is to measure the easier method of cholinium ionization.The specific conductivity of same concentration differing temps is linear, increases with the rising of temperature, and this point is the same with other ionogen.The specific conductivity detected result shows that choline is a highly basic less than 0.5M the time.
Aqueous choline base solution is decomposed near 100 ℃ the time, and principal reaction is:
0.5M choline solution in 75 ℃ of waters bath with thermostatic control, place 28h and do not have change in concentration, obviously do not decompose, because any decomposition can cause the noticeable change led than electricity.Described thermolysis can not become the problem that the present invention applies, the severe condition that the choline that this experiment has repeated decomposes.In actually operating, choline solution partly is converted into the choline aluminide, and this also can reduce the rate of decomposition of choline conversely.As previously mentioned, purity is the alumina product sixty-four dollar question.Though inevitably can bring impurity in the operating process, as long as the final product purity of carefully handled has still surpassed 99.99% target (seeing Table 1).
Table 1
Original aluminum Aluminium hydroxide The comminution by gas stream aluminum oxide
Si 0.0015 0.0012 0.0020
Fe 0.0010 0.0010 0.0015
Ca 0.0010 0.0012 0.0010
Mg 0.0004 0.0004 0.0005
Na 0.0010 0.0011 0.0010
Cu 0.0015 0.0007 0.0010
Impurity amounts to 0.0064 0.0056 0.0070
Purity 99.9936 99.9944 99.9930
Calcining exist with the fore portion choline with aluminium hydroxide in, but can residual carbon and nitrogen after the calcining.The granularity of the aluminium hydroxide of producing in the reactor is decided by the existence of temperature, degree of supersaturation, crystal seed.Yet in plant-scale operation, these parameters all keep relative stability, yet size-grade distribution can change by the retouching operation parameter.The size-grade distribution that separate out, calcine, grinding and the correct coupling of fractionated can be produced any needs.
The specific surface of aluminium hydroxide is 25-60m 2/ g, high like this specific surface come from separate out during the reunion of small-crystalline.Calcinations of aluminum hydroxide can produce 2-400m 2/ g specific surface area.
When not having crystal seed, the crystalline phase of the aluminium hydroxide that choline and metallic aluminium reaction generate is a bayerite.
After producing aluminium hydroxide, adopt traditional calcining and grinding explained hereafter αYang Hualv, by the character optimizing that adjusting is separated out, calcined, grinding, progressive operation can make final αYang Hualv product, to satisfy the concrete needs of using.
The aluminum oxide of present method preparation is specially adapted to high-pressure sodium fluorescent tube, rare earth luminescent material, senior abrasive substance, fine ceramics field.
Embodiment: the aluminium foil 100g that 0.1mm is thick puts into 1000 milliliters beaker, the aqueous choline base solution that adds 600 milliliters of 0.5M, be placed in 75 ℃ the water bath with thermostatic control, per 30 minutes with the rod stirring once, reacted 24 hours, at this moment most aluminium foils have changed into aluminium hydroxide powder, remaining minute quantity unreacted aluminium foil completely is deposited in the bottom of beaker, crosses 100 mesh sieves, and sieve is aluminium hydroxide down, it on the sieve unreacted aluminium foil completely, about 5g that weighs after the oven dry, with the aluminium hydroxide vacuum filtration, filtrate is returned beaker, filter cake 1200 ℃ of calcinings 4 hours, obtains α-Al with the high temperature retort furnace 2O 3Powder 183g.

Claims (2)

1, a kind of preparation method of high purity aluminium oxide is characterized in that adopting following processing method to obtain high-purity αYang Hualv:
I) raw material: purity is 99.996% refined aluminium; The choline that adopts reinforcing yin essence ion exchange resin that choline chloride 60 is transformed and generate;
The reaction vessel that ii) adopts polyvinyl chloride, tetrafluoroethylene or the polypropylene plastics of anti-highly basic to make, temperature is controlled by built-in pipeline by circulating water and hot water, is reflected to stir the realization down of pressurized air bubbling;
Iii) temperature of reaction is controlled at 20-80 ℃, and choline concentration is controlled at 0.1-2.0M, and the aluminium hydroxide of acquisition is at 110 ℃ of air dryings;
Iv) refined aluminium, water, choline react under above-mentioned processing condition, judge speed of response by monitoring hydrogen effusion speed, and be very low or when stopping when speed of response, removes slurry, carries out solid-liquid separation, periodically adds refined aluminium, removes slurry; Aluminium hydroxide obtains dry powder by filtration, spraying drying, choline loops back reaction vessel, dried aluminium hydroxide is placed in kiln in the high purity aluminium oxide crucible and calcines, and the aluminium hydroxide after the calcining is pulverized at ball mill with the high purity aluminium oxide ball and obtained αYang Hualv, and purity can reach 99.99%.
2, the preparation method of high purity aluminium oxide according to claim 1 is characterized in that: temperature of reaction is controlled at 75 ℃, and choline concentration is controlled at 0.5M.
CNB021089914A 2002-04-19 2002-04-19 Prepn of high-purity alumina Expired - Lifetime CN1182037C (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1974867B (en) * 2006-11-28 2011-07-20 河南大学 Aluminium anode consuming process in water solution for producing micron or nanometer aluminium particle
JP2010168271A (en) * 2008-12-25 2010-08-05 Sumitomo Chemical Co Ltd Method for producing alumina
CA2773571A1 (en) * 2009-09-18 2011-03-24 Eestor, Inc. Selective-cation-removal purification of aluminum source
CN102173756B (en) * 2011-01-30 2013-03-20 河北恒博精细陶瓷材料有限公司 Preparation method of high-purity aluminum oxide sintered body for growing sapphire crystal
CN102674419B (en) * 2011-11-22 2014-02-05 昆明马克西姆科技有限公司 Preparation method of high-purity ultrafine Al2O3 powder
CN103241756A (en) * 2012-02-03 2013-08-14 上海飞凯光电材料股份有限公司 Preparation method for alumina solid
CN103663525B (en) * 2012-09-24 2016-04-20 韩香娟 Methylamine legal system is for high purity aluminium oxide
CA2895229C (en) * 2012-12-17 2021-10-26 Polar Sapphire Ltd. Process for making high-purity aluminum oxide from a high purity aluminum starting material
CN103043692B (en) * 2012-12-27 2016-03-30 西安迈克森新材料有限公司 A kind of preparation method of high-purity aluminum oxide powder material
JP2022529200A (en) * 2019-04-16 2022-06-20 フィナジー リミテッド Manufacture of high-purity alumina and co-products from used electrolytes in metal-air batteries
CN110683569A (en) * 2019-11-13 2020-01-14 山东恒嘉高纯铝业科技股份有限公司 Method for producing alumina superfine powder in large batch at low cost
CN115196658B (en) * 2022-05-18 2023-11-21 陕西煤业化工技术研究院有限责任公司 High-purity alumina powder prepared rapidly through self-catalysis and method
CN116282107B (en) * 2023-01-31 2024-07-02 中铝山东有限公司 Method for preparing 4N-grade high-purity aluminum oxide through continuous seed precipitation

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