JPH07291622A - Production of transition alumina from aluminum sulfate - Google Patents
Production of transition alumina from aluminum sulfateInfo
- Publication number
- JPH07291622A JPH07291622A JP7036932A JP3693295A JPH07291622A JP H07291622 A JPH07291622 A JP H07291622A JP 7036932 A JP7036932 A JP 7036932A JP 3693295 A JP3693295 A JP 3693295A JP H07291622 A JPH07291622 A JP H07291622A
- Authority
- JP
- Japan
- Prior art keywords
- aluminum sulfate
- water
- transition alumina
- alumina
- specific surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 title claims abstract description 106
- 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 103
- 230000007704 transition Effects 0.000 title claims abstract description 80
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 64
- 238000001035 drying Methods 0.000 claims abstract description 41
- 239000013078 crystal Substances 0.000 claims abstract description 17
- 230000008020 evaporation Effects 0.000 claims abstract description 13
- 238000001704 evaporation Methods 0.000 claims abstract description 13
- 150000004687 hexahydrates Chemical class 0.000 claims abstract description 9
- 238000010304 firing Methods 0.000 claims description 29
- 238000002425 crystallisation Methods 0.000 claims description 22
- 230000008025 crystallization Effects 0.000 claims description 22
- 238000005979 thermal decomposition reaction Methods 0.000 claims description 17
- 229910052746 lanthanum Inorganic materials 0.000 claims description 11
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical group [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 11
- 150000002604 lanthanum compounds Chemical class 0.000 claims description 11
- 150000004677 hydrates Chemical class 0.000 claims description 5
- 150000003839 salts Chemical class 0.000 claims description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims 1
- 239000003054 catalyst Substances 0.000 abstract description 22
- 150000004689 octahydrates Chemical class 0.000 abstract description 8
- 238000000197 pyrolysis Methods 0.000 abstract description 5
- 230000009467 reduction Effects 0.000 abstract description 4
- 238000002485 combustion reaction Methods 0.000 abstract description 2
- 229910052593 corundum Inorganic materials 0.000 abstract 1
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract 1
- 238000000034 method Methods 0.000 description 44
- 238000010438 heat treatment Methods 0.000 description 34
- 238000012856 packing Methods 0.000 description 25
- 239000007789 gas Substances 0.000 description 22
- 239000002994 raw material Substances 0.000 description 20
- 230000018044 dehydration Effects 0.000 description 14
- 238000006297 dehydration reaction Methods 0.000 description 14
- 239000002245 particle Substances 0.000 description 11
- 238000000354 decomposition reaction Methods 0.000 description 8
- 238000005273 aeration Methods 0.000 description 7
- 238000005187 foaming Methods 0.000 description 7
- 238000011084 recovery Methods 0.000 description 7
- 239000007864 aqueous solution Substances 0.000 description 6
- 230000007423 decrease Effects 0.000 description 6
- BUACSMWVFUNQET-UHFFFAOYSA-H dialuminum;trisulfate;hydrate Chemical compound O.[Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O BUACSMWVFUNQET-UHFFFAOYSA-H 0.000 description 6
- 238000001354 calcination Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- 239000000654 additive Substances 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052788 barium Inorganic materials 0.000 description 3
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 3
- 239000000969 carrier Substances 0.000 description 3
- 238000012937 correction Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000003381 stabilizer Substances 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- -1 aluminum alkoxide Chemical class 0.000 description 2
- 238000007084 catalytic combustion reaction Methods 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005469 granulation Methods 0.000 description 2
- 230000003179 granulation Effects 0.000 description 2
- JLRJWBUSTKIQQH-UHFFFAOYSA-K lanthanum(3+);triacetate Chemical compound [La+3].CC([O-])=O.CC([O-])=O.CC([O-])=O JLRJWBUSTKIQQH-UHFFFAOYSA-K 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- 239000010948 rhodium Substances 0.000 description 2
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- 229910052684 Cerium Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- MJWPFSQVORELDX-UHFFFAOYSA-K aluminium formate Chemical compound [Al+3].[O-]C=O.[O-]C=O.[O-]C=O MJWPFSQVORELDX-UHFFFAOYSA-K 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000001739 density measurement Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 229910001679 gibbsite Inorganic materials 0.000 description 1
- 150000004688 heptahydrates Chemical class 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 150000004686 pentahydrates Chemical class 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000011802 pulverized particle Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000011172 small scale experimental method Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000000629 steam reforming Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- VXYADVIJALMOEQ-UHFFFAOYSA-K tris(lactato)aluminium Chemical compound CC(O)C(=O)O[Al](OC(=O)C(C)O)OC(=O)C(C)O VXYADVIJALMOEQ-UHFFFAOYSA-K 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は高比表面積を有する遷移
アルミナの製造方法に関する。更に詳細には接触燃焼触
媒あるいは自動車排気ガス浄化用触媒等の触媒担体に適
した高比表面積を有する硫酸アルミニウムからの遷移ア
ルミナの工業的製造方法に関するものである。FIELD OF THE INVENTION The present invention relates to a method for producing a transition alumina having a high specific surface area. More specifically, it relates to a method for industrially producing transition alumina from aluminum sulfate having a high specific surface area suitable for a catalyst carrier such as a catalytic combustion catalyst or a catalyst for purifying automobile exhaust gas.
【０００２】[0002]
【従来の技術】触媒或いは触媒担体は、自動車排ガス除
去、高温水蒸気改質、炭化水素や水素の接触燃焼等の化
学プロセスへの応用、更には、ガスタ−ビンやボイラ−
等の高温下での触媒反応分野への適用等、近年その用途
は、ますます多用化の傾向にある。2. Description of the Related Art Catalysts or catalyst carriers are applied to chemical processes such as automobile exhaust gas removal, high temperature steam reforming, catalytic combustion of hydrocarbons and hydrogen, and further gas turbines and boilers.
In recent years, the applications thereof are becoming more and more versatile, such as the application to the field of catalytic reactions under high temperature.
【０００３】これら分野に用いられる担体は触媒成分の
有効利用の点より比表面積の高い触媒担体、通常γ−ア
ルミナを主体とする遷移アルミナが多く使用されている
が、これら担体の使用温度は９００℃以上、時には１０
００℃、さらには１２００℃を越える場合もあり、この
条件下の使用において初期比表面積が高く、かつ比表面
積の低下が少ない耐熱性に優れた特性を有する触媒担体
が要求されている。また、アルミナ担体への触媒金属の
担持性の点からは初期の比表面積が高い遷移アルミナが
要求されている。As a carrier used in these fields, a catalyst carrier having a high specific surface area, usually a transition alumina mainly composed of γ-alumina, is often used from the viewpoint of effective utilization of the catalyst component. ℃ or more, sometimes 10
There are cases where the temperature exceeds 00 ° C., and even 1200 ° C., and there is a demand for a catalyst carrier that has a high initial specific surface area under these conditions and has excellent heat resistance with a small decrease in the specific surface area. In addition, transitional alumina having a high initial specific surface area is required from the viewpoint of supporting the catalytic metal on the alumina carrier.
【０００４】遷移アルミナの欠点は周知のように９００
℃以上の高温下に曝されるとα−アルミナ晶へと結晶転
移を起こし、著しく比表面積が低下する。The disadvantages of transitional aluminas are well known as 900
When it is exposed to a high temperature of ℃ or more, a crystal transition occurs to α-alumina crystal, and the specific surface area remarkably decreases.
【０００５】また触媒担体として遷移アルミナをペレッ
ト状もしくは他の形状の成形物に被覆した態様において
使用する場合には、この結晶転移による構造変化が被覆
層の脱落あるいは触媒成分のシンタリングを促進させる
原因となる。When a transition alumina is used as a catalyst carrier in the form of a pellet-shaped or other shaped article coated, the structural change due to the crystal transition promotes the removal of the coating layer or the sintering of the catalyst component. Cause.
【０００６】この遷移アルミナにおける比表面積の低下
を防止する等、熱安定性の向上を計る方法として、ラン
タン等の希土類元素あるいは、バリウム等の元素を硫酸
アルミニウムに添加混合し、乾燥後焼成することにより
耐熱性遷移アルミナを製造することは公知である。As a method for improving the thermal stability, for example, by preventing the reduction of the specific surface area of the transition alumina, a rare earth element such as lanthanum or an element such as barium is added and mixed with aluminum sulfate, followed by drying and firing. It is known to produce refractory transition aluminas according to.
【０００７】しかし、この遷移アルミナにおける比表面
積の低下を防止するため添加剤を添加する方法は、かか
る方法で得られた遷移アルミナを触媒担体として用い、
該担体に触媒を担持させる場合に比表面積の低下防止に
用いた添加剤が担持する金属の触媒作用を変化させるこ
とがあり、場合によっては好ましくない。また、遷移ア
ルミナのコストを引き上げる等経済的な問題をも有す
る。However, the method of adding an additive in order to prevent the reduction of the specific surface area of the transition alumina is as follows:
When the catalyst is supported on the carrier, the additive used to prevent the reduction of the specific surface area may change the catalytic action of the metal supported, which is not preferable in some cases. Further, there is an economical problem such as an increase in the cost of transition alumina.
【０００８】従来、添加剤を添加しないで遷移アルミナ
を作る方法として、アルミニウムアルコキシドの加水分
解により発生したゾル溶液を、超音波振動子で噴霧させ
て瞬間的に焼成する方法（石油学会誌、３４、（６）、
４８３（１９９１））が、知られている。この方法はゾ
ル溶液を、超音波振動子で噴霧し瞬間焼成するため、噴
霧のために大量のエネルギ−が必要であり、また瞬間的
に焼成するために大量の熱が短期間に必要となるため、
工業的でない。Conventionally, as a method for producing transition alumina without adding an additive, a method in which a sol solution generated by hydrolysis of aluminum alkoxide is sprayed with an ultrasonic oscillator and instantaneously fired (Petroleum Society of Japan, 34 , (6),
483 (1991)) is known. This method requires a large amount of energy for spraying because the sol solution is sprayed with an ultrasonic oscillator and instantaneously baked, and a large amount of heat is required for a short time for instantaneously baking. For,
Not industrial.
【０００９】また、硫酸アルミニウムを原料として熱分
解法により添加物を含まない遷移アルミナを得ることは
公知である。（例えば、特開昭６０−１７１２２０号、
特開平５−２６２５１７号の実施例１、共立出版現代化
学講座１８無機合成化学II第１１３ペ−ジ）。これら公
知文献に見られる遷移アルミナは、かなり高い初期比表
面積を有する遷移アルミナが得られている。例えば、
（共立出版現代化学講座１８無機合成化学II第１１３ペ
−ジ）には１４５ｍ2 ／ｇと１７５ｍ2 ／ｇの初期比表
面積の遷移アルミナが見られる。また特開平５−２６２
５１７号の実施例１には、１０００℃１時間加熱後の比
表面積が１２０ｍ2 ／ｇの遷移アルミナが見られる。し
かしこれらはいずれもビーカや坩堝を用い、電気炉やマ
ッフル炉で加熱、分解する小規模な実験例が教示されて
いるのみで、工業規模での例は見られない。It is also known to obtain transition alumina containing no additives by a thermal decomposition method using aluminum sulfate as a raw material. (For example, JP-A-60-171220,
Example 1 of JP-A-5-262517, Kyoritsu Shuppan Contemporary Chemistry Course 18 Inorganic Synthetic Chemistry II, 113th page). Regarding the transition aluminas found in these known documents, transition aluminas having a considerably high initial specific surface area have been obtained. For example,
(Kyoritsu Shuppan Contemporary Chemistry Course 18 Inorganic Synthetic Chemistry II, 113th page) shows transitional aluminas having initial specific surface areas of 145 m 2 / g and 175 m 2 / g. In addition, JP-A-5-262
In Example 517 of No. 517, transition alumina having a specific surface area of 120 m 2 / g after heating at 1000 ° C. for 1 hour is found. However, all of these teach only small-scale experimental examples of heating and decomposing in an electric furnace or a muffle furnace using a beaker or a crucible, and no examples on an industrial scale are seen.
【００１０】本発明者等は工業規模での生産に適した方
法を探索すべく、硫酸アルミニウムの熱分解をロータリ
ーキルン、瞬間仮焼炉、流動焼成炉等を用い鋭意検討し
たが、これら工業規模での熱分解に適した方法に於いて
は、得られる遷移アルミナの製品収率が低く、また得ら
れる初期比表面積や耐熱性も小規模実験に比較し著しく
低下する場合があり、必ずしも満足し得るものではなか
った。The present inventors diligently investigated the thermal decomposition of aluminum sulfate using a rotary kiln, a flash calcination furnace, a fluidized-bed calcination furnace, etc. in order to search for a method suitable for production on an industrial scale. In the method suitable for thermal decomposition of, the product yield of the obtained transition alumina is low, and the initial specific surface area and heat resistance obtained may be remarkably reduced as compared with the small-scale experiment, which is not always satisfactory. It wasn't something.
【００１１】[0011]
【発明が解決しようとする課題】かかる状況下を鑑み、
本発明者らは遷移アルミナの製品収率に優れ、初期比表
面積が大きく、かつ耐熱性に優れた遷移アルミナを得る
べく鋭意検討した結果、特定条件で加熱乾燥固化した硫
酸アルミニウムを特定の焼成装置を用いて焼成し熱分解
する場合には製品収率よく、初期比表面積の高い遷移ア
ルミナが得られること、また該熱分解時に焼成炉を通過
する気流の空塔速度を特定範囲に調整し焼成する場合に
は、ランタンやバリウム等の安定剤が無添加である場合
であっても耐熱性に優れた遷移アルミナが得られるこ
と、更には該熱分解時に用いる通気ガスの水蒸気濃度を
特定範囲に調湿する場合には極めて高い初期比表面積を
有する遷移アルミナが得られることを見出し、本発明を
完成するに至った。In view of such a situation,
As a result of intensive investigations by the present inventors to obtain a transition alumina having excellent transition alumina product yield, large initial specific surface area, and excellent heat resistance, aluminum sulfate heat-dried and solidified under specific conditions is subjected to a specific firing apparatus. In the case of calcination and pyrolysis, a transition alumina having a high product yield and a high initial specific surface area can be obtained, and the superficial velocity of the air flow passing through the calcination furnace during the pyrolysis is adjusted to a specific range for calcination. In that case, even if no stabilizer such as lanthanum or barium is added, a transition alumina having excellent heat resistance can be obtained, and further, the water vapor concentration of the aeration gas used during the thermal decomposition is within a specific range. It was found that transition alumina having an extremely high initial specific surface area can be obtained when the humidity is controlled, and the present invention has been completed.
【００１２】[0012]
【課題を解決するための手段】すなわち本発明は、硫酸
アルミニウムの結晶水に換算して８水塩を越える水を含
有する硫酸アルミニウムを、硫酸アルミニウム〔Ａｌ2
（ＳＯ4 ）3 として〕１ｇ当たりからの水の蒸発速度が
０．０１ｍｇ／ｓｅｃ〜２．０ｍｇ／ｓｅｃで８水塩以
下の結晶水に相当する水含有量の硫酸アルミニウムとな
るまで乾燥し、該乾燥後の硫酸アルミニウムを必要に応
じて６水塩以下の結晶水に相当する水含有量の硫酸アル
ミニウムとなるまで乾燥した後、該乾燥後の６水塩以下
の結晶水に相当する水含有量の硫酸アルミニウムを竪型
気流接触式焼成炉に供給し、該焼成炉中で熱分解し遷移
アルミナを得ることを特徴とする、硫酸アルミニウムか
らの遷移アルミナの製造方法を提供するにある。That is, according to the present invention, the aluminum sulfate containing aluminum sulphate [Al 2
(SO 4) evaporation rate of water from] 1g per a 3 is dried to 0.01mg / sec~2.0mg / sec at octahydrate following water content of aluminum sulfate corresponding to crystal water, If necessary, the dried aluminum sulfate is dried to aluminum sulfate having a water content corresponding to the water of crystallization of 6 hydrate or less, and then the water containing the water of crystallization of 6 hydrate or less is dried. An object of the present invention is to provide a method for producing transition alumina from aluminum sulfate, which comprises supplying a quantity of aluminum sulfate to a vertical airflow contact type firing furnace and thermally decomposing in the firing furnace to obtain transition alumina.
【００１３】以下、本発明を更に詳細に説明する。本発
明において使用される硫酸アルミニウムは、硫酸アルミ
ニウムの結晶水に換算して８水塩を越える水を含有する
硫酸アルミニウム、普通には１０水塩以上、より好まし
くは２０水塩以上の水を含有する硫酸アルミニウムであ
ればよく、通常一般式Ａｌ2 （ＳＯ4 ）3 ・ｎＨ2 Ｏ
（式中、ｎ＞８である）で表される市販の固体硫酸アル
ミニウム、あるいは液体の硫酸アルミニウムが使用され
る。原料としての硫酸アルミニウムは液状でも固体状で
も良く、通常バイヤ−法で得られたギブサイトを硫酸と
反応させて得られたものが適用される。The present invention will be described in more detail below. The aluminum sulphate used in the present invention contains aluminum sulphate which contains more than 8 hydrates of water converted to crystallization water of aluminum sulphate, usually 10 hydrates or more, more preferably 20 hydrates or more. Aluminum sulfate, which has the general formula Al 2 (SO 4 ) 3 · nH 2 O
Commercially available solid aluminum sulfate represented by the formula (where n> 8) or liquid aluminum sulfate is used. Aluminum sulfate as a raw material may be liquid or solid, and the one obtained by reacting gibbsite obtained by the Bayer method with sulfuric acid is usually applied.
【００１４】また原料としての硫酸アルミニウムは、所
望とする初期比表面積を有する遷移アルミナの得られる
範囲で、硫酸アルミニウムに他のアルミニウム塩、例え
ば塩化アルミニウム、硝酸アルミニウム、蟻酸アルミニ
ウム、乳酸アルミニウム、および酢酸アルミニウムやア
ルミナ水和物、酸化アルミニウムあるいはアルミニウム
アルコキサイド等を併用しても良い。Further, aluminum sulfate as a raw material is aluminum sulfate and other aluminum salts such as aluminum chloride, aluminum nitrate, aluminum formate, aluminum lactate, and acetic acid as long as a transition alumina having a desired initial specific surface area can be obtained. Aluminum, alumina hydrate, aluminum oxide, aluminum alkoxide, etc. may be used together.
【００１５】本発明の原料硫酸アルミニウムとしては特
に制限されるものではないが、Ｆｅ、Ｎａ，Ｋ，Ｃａ，
Ｓｉ，Ｍｇの無機不純物の総量が３０ｐｐｍ以下の高純
度の硫酸アルミニウムを用いる場合には耐熱性の優れ
た、例えばランタン等の安定剤を添加しなくても１２０
０℃、３時間加熱処理後も約５０ｍ2 ／ｇ以上の高い比
表面積を示す遷移アルミナを得ることができる。The raw material aluminum sulfate of the present invention is not particularly limited, but may be Fe, Na, K, Ca,
When using high-purity aluminum sulfate in which the total amount of inorganic impurities of Si and Mg is 30 ppm or less, it is possible to use a high-heat-resistant aluminum sulfate without adding a stabilizer such as lanthanum.
It is possible to obtain a transition alumina having a high specific surface area of about 50 m 2 / g or more even after heat treatment at 0 ° C. for 3 hours.
【００１６】本発明の実施に際し、硫酸アルミニウムは
結晶水の含有量が８水塩以下になる迄加熱し、乾燥、固
化する。加熱は原料硫酸アルミニウムを硫酸アルミニウ
ムの結晶水に換算して、８水塩以下の水を有する硫酸ア
ルミニウムになるまで乾燥するが、この場合乾燥後の硫
酸アルミニウムが実質的に発泡しない条件で乾燥する。
かかる乾燥方法としては原料硫酸アルミニウムを、Ａｌ
2 （ＳＯ4 ）3 に換算して硫酸アルミニウム１ｇ当たり
の蒸発速度が０．０１ｍｇ／ｓｅｃ〜２．０ｍｇ／ｓｅ
ｃの範囲で乾燥すればよい。In carrying out the present invention, aluminum sulfate is heated until the content of water of crystallization becomes not more than octahydrate, dried and solidified. The heating is performed by converting the raw material aluminum sulfate into water of crystallization of aluminum sulfate and drying until aluminum sulfate having water of octahydrate or less is obtained, but in this case, it is dried under the condition that the dried aluminum sulfate does not substantially foam. .
As such a drying method, aluminum sulfate is used as a raw material.
When converted into 2 (SO 4 ) 3 , the evaporation rate per 1 g of aluminum sulfate is 0.01 mg / sec to 2.0 mg / se.
It may be dried in the range of c.
【００１７】結晶水の蒸発速度が２．０ｍｇ／ｓｅｃを
越える場合、得られる８水塩以下の結晶水に相当する水
を含有する硫酸アルミニウムは実質的に発泡しており、
強度が弱いため粉化し十分な通気焼成ができないとか、
粉化した粒子が通気ガスにより逸散し、歩留まりが低下
し経済性が悪化する。また、結晶水の蒸発速度が０．０
１ｍｇ／ｓｅｃ未満の場合には乾燥速度が遅く生産性が
劣るため経済的でない。硫酸アルミニウムの乾燥工程
は、上記乾燥速度で乾燥できる設備であれば特に制限さ
れるものではないが、例えば、オ−ブン、オイルバス、
通気乾燥装置、ベルト乾燥機、ロ−タリ−乾燥機、流動
乾燥機等の公知の方法が使用できる。When the evaporation rate of water of crystallization exceeds 2.0 mg / sec, the obtained aluminum sulfate containing water corresponding to water of crystallization of octahydrate or less is substantially foamed,
Because the strength is weak, it cannot be pulverized and aerated with sufficient ventilation,
The pulverized particles dissipate due to the ventilation gas, which lowers the yield and deteriorates the economic efficiency. In addition, the evaporation rate of crystal water is 0.0
If it is less than 1 mg / sec, the drying speed is slow and the productivity is poor, which is not economical. The drying process of aluminum sulfate is not particularly limited as long as it is equipment capable of drying at the above-mentioned drying speed, but, for example, an oven, an oil bath,
Known methods such as an aeration dryer, a belt dryer, a rotary dryer and a fluid dryer can be used.
【００１８】このように、本発明の実施に際しては、原
料硫酸アルミニウムは、該硫酸アルミニウムが有する水
量が硫酸アルミニウムの結晶水に換算して８水塩以下に
なるまで実質的に発泡が生じない条件、即ち上記乾燥速
度で加熱、乾燥する。乾燥は８水塩以下、通常６水塩以
下まで上記乾燥速度で実施する。勿論、上記乾燥速度で
無水塩に相当するまで、乾燥してもよい。上記条件での
乾燥を硫酸アルミニウムの結晶水に換算して８水塩以下
でかつ６水塩を越える時点で終えた場合には、乾燥条件
は制限されないが、更に加熱、乾燥し、硫酸アルミニウ
ムに含有される水を結晶水に換算して６水塩以下にす
る。該乾燥後の硫酸アルミニウムの含有水が６水塩を越
える場合には、焼成工程において硫酸アルミニウムは徐
々に粘性を増し粒子同士が粘着し、次いで発泡がおこり
強度が低下するため、通気焼成におけるガスの偏流や粒
子の破壊による飛散が生じ、歩留まりが低下するので、
工業的に安価に通気焼成が出来ない。得られた硫酸アル
ミニウムが実質的に発泡しているか否かは目視でも視認
可能であるが、２ｍｍ〜６．７ｍｍ（ＪＩＳ篩）に整粒
した未乾燥品の硫酸アルミニウムの重量を測定し、該未
乾燥品の有する結晶水が完全に除かれた場合の重量を算
出し、これにより計算で求めた充填密度（平均０．５０
ｇ／ｃｃであった）の値を未発泡の硫酸アルミニウムの
基準充填密度と定め、この基準充填密度と以下に記載す
る方法で測定し、補正した試料の充填密度とを比較する
事により、発泡の程度を表すことが可能である。本発明
に於いては充填密度が０．４５ｇ／ｃｃ未満のものは実
質的に発泡していると判断した。試料の充填密度測定・
補正方法；乾燥後の硫酸アルミニウム１００ｇを２００
ｃｃメスシリンダーに入れ、シリンダーを３ｃｍの高さ
より１００回落下させた後充填密度（ｇ／ｃｃ）を測定
し（乾燥品の充填密度）、次いで該乾燥品の重量を測定
し、更に５００℃、２時間加熱して乾燥品中の結晶水を
前部脱水させた後重量を測定し、以下の式より試料の充
填密度を求めた。 補正した試料の充填密度 ＝ 乾燥品の充填密度 ×
〔５００℃脱水後の重量／５００℃脱水前の乾燥品重
量〕As described above, in the practice of the present invention, the raw material aluminum sulfate is substantially free from foaming until the amount of water contained in the aluminum sulfate is not more than octahydrate when converted to crystal water of aluminum sulfate. That is, heating and drying are performed at the above drying rate. Drying is carried out at the above-mentioned drying speed up to octahydrate, usually 6 hexahydrate or less. Of course, you may dry until it corresponds to an anhydrous salt in the said drying rate. When the drying under the above conditions is finished at a time of not more than 8 hydrate and more than 6 hydrate in terms of water of crystallization of aluminum sulfate, the drying conditions are not limited, but further heating and drying to give aluminum sulfate. The water contained is converted to water of crystallization so as to have a hexahydrate or less. When the water content of the aluminum sulfate after drying exceeds hexahydrate, the aluminum sulfate gradually increases in viscosity in the firing step, particles adhere to each other, and then foaming occurs to lower the strength. Uneven distribution and scattering of particles will occur, and the yield will decrease.
Aeration firing cannot be industrially inexpensive. Whether or not the obtained aluminum sulfate is substantially foamed can be visually confirmed, but the weight of the undried aluminum sulfate that has been sized to 2 mm to 6.7 mm (JIS sieve) is measured, and The weight of the undried product when the water of crystallization was completely removed was calculated, and the packing density (average 0.50
The value of (g / cc) was defined as the standard packing density of unfoamed aluminum sulfate, and the standard packing density was measured by the method described below and the packing density of the corrected sample was compared. It is possible to express the degree of. In the present invention, those having a packing density of less than 0.45 g / cc were judged to be substantially foamed. Sample packing density measurement
Correction method: 200 g of aluminum sulfate after drying to 200 g
cc graduated cylinder, after dropping the cylinder 100 times from a height of 3 cm, the packing density (g / cc) is measured (the packing density of the dry product), then the weight of the dry product is measured, and further 500 ° C. After heating for 2 hours to dehydrate the water of crystallization in the dried product in the front, the weight was measured, and the packing density of the sample was determined from the following formula. Corrected sample packing density = Dry product packing density x
[Weight after dehydration at 500 ° C / Weight of dried product before dehydration at 500 ° C]
【００１９】このようにして得られた実質的に発泡のな
い硫酸アルミニウムは次いで竪型気流接触式焼成炉よ
り、硫酸アルミニウムを熱分解する。熱分解に供する硫
酸アルミニウムは結晶水に換算して６水塩以下に相当す
る水を含有する硫酸アルミニウムである。該、竪型気流
接触式焼成炉は焼成炉中に乾燥後の硫酸アルミニウムを
充填し、充填床内を通過する気流と接触させながら熱分
解するものであり、具体的には、新化学工学講座III −
６ 窯炉（功刀雅長著，日刊工業新聞社発行）の第１０
５頁〜第１０６頁に記載の竪窯（シャフトキルン）等の
公知の焼成装置が適用される。 通気ガスと硫酸アルミ
ニウムの接触は向流でも並流でもどちらでも良く、また
バッチでも移動床でも良い。しかし、熱伝達の優れた向
流移動床方式が工業的に有利であり好ましい。The substantially unfoamed aluminum sulfate thus obtained is then thermally decomposed in a vertical airflow contact type firing furnace. Aluminum sulfate to be subjected to thermal decomposition is aluminum sulfate containing water equivalent to hexahydrate or less in terms of crystal water. The vertical airflow contact type firing furnace is one in which dried aluminum sulfate is filled in the firing furnace and pyrolyzed while being in contact with the airflow passing through the packed bed. III −
6th kiln (written by Masanori Kouto, published by Nikkan Kogyo Shimbun) No. 10
A known firing device such as a kiln (shaft kiln) described on pages 5 to 106 is applied. The contact between the vent gas and aluminum sulfate may be countercurrent or cocurrent, and may be batch or moving bed. However, a countercurrent moving bed system having excellent heat transfer is industrially advantageous and preferable.
【００２０】焼成炉中に充填される硫酸アルミニウムの
結晶水に換算して６水塩以下の水を有する硫酸アルミニ
ウムは、熱分解時充填床内を熱風が通過し易くするため
に平均粒径で約０．５ｍｍ〜約５０ｍｍ，好ましくは約
１ｍｍ〜約２０ｍｍの塊状或いは板状で用いることが好
ましい。このような方法として、原料が硫酸アルミニウ
ム水溶液の場合には硫酸アルミニウム水溶液を加熱し、
該硫酸アルミニウムが流動性を有する間に板状や塊状に
凝固し、或いは成形し、必要に応じてこれを所望形状に
粉砕した後、乾燥し焼成することができる。或いは硫酸
アルミニウム水溶液を加熱することなく凝固温度以下ま
で冷却し次いでこれを所望形状に粉砕した後、乾燥し焼
成することもできる。また原料が固体の場合には粉砕
し、粉状にした後、転動造粒や押出し成形等の既存の方
法で所望形状に成形後、乾燥し、充填焼成することが好
ましい。勿論、原料粒径を整える目的より、必要ならば
乾燥前、或いは乾燥後の成形体を篩別し、焼成して熱分
解することもできる。Aluminum sulfate having a water content of 6-hydrate or less in terms of the water of crystallization of aluminum sulfate charged in the firing furnace has an average particle size of 30 μm in order to facilitate passage of hot air through the packed bed during thermal decomposition. It is preferable to use in the form of a lump or plate having a thickness of about 0.5 mm to about 50 mm, preferably about 1 mm to about 20 mm. As such a method, when the raw material is an aluminum sulfate aqueous solution, the aluminum sulfate aqueous solution is heated,
While the aluminum sulfate has fluidity, it can be solidified or shaped into a plate or a lump, and if necessary, this can be crushed into a desired shape, then dried and fired. Alternatively, the aluminum sulfate aqueous solution may be cooled to a solidification temperature or lower without heating and then crushed into a desired shape, followed by drying and firing. When the raw material is a solid, it is preferable to grind it into a powder, and then to form it into a desired shape by an existing method such as rolling granulation or extrusion molding, and then dry, fill and bake. Of course, for the purpose of adjusting the particle size of the raw material, the molded product before or after drying may be sieved and pyrolyzed by firing if necessary.
【００２１】本発明の実施に際し、硫酸アルミニウムの
焼成（分解）は、硫酸アルミニウムの熱分解温度以上
で、かつ分解後得られる遷移アルミナの比表面積が可能
な限り高くなる条件、通常、硫酸アルミニウムの温度が
大気中で約７００℃〜約１０００℃になる通気ガス温度
で１時間〜１００時間、好ましくは約７５０℃〜約９５
０℃になる通気ガス温度で５時間〜２０時間程度焼成す
ればよい。In carrying out the present invention, the firing (decomposition) of aluminum sulfate is carried out under the conditions that the temperature is not lower than the thermal decomposition temperature of aluminum sulfate and the specific surface area of the transition alumina obtained after the decomposition is as high as possible. 1 hour to 100 hours, preferably about 750 ° C. to about 95 at an aeration gas temperature at which the temperature is about 700 ° C. to about 1000 ° C. in the atmosphere.
It suffices to perform firing for 5 to 20 hours at an aeration gas temperature of 0 ° C.
【００２２】充填床を通過するガスの空塔線速度は約
０．０１Ｎｍ／ｓ〜約１．０Ｎｍ／ｓ、好ましくは約
０．１Ｎｍ／ｓ〜約０．５Ｎｍ／ｓの範囲である。原因
は定かでないが風速が１．０Ｎｍ／ｓを越えて大きくな
ると得られた遷移アルミナの細孔容積が小さくなり、耐
熱性が低下する傾向を示す。またガスの空塔線速度が
０．０１Ｎｍ／ｓ未満では、発生した分解ガスの置換が
速やかに行われないためか焼成に時間がかかり経済的で
ない。The superficial linear velocity of the gas passing through the packed bed is in the range of about 0.01 Nm / s to about 1.0 Nm / s, preferably about 0.1 Nm / s to about 0.5 Nm / s. Although the cause is not clear, when the wind velocity exceeds 1.0 Nm / s and becomes large, the pore volume of the obtained transition alumina becomes small, and the heat resistance tends to decrease. If the superficial linear velocity of the gas is less than 0.01 Nm / s, it may be uneconomical because it takes a long time to perform the firing, probably because the generated decomposition gas is not replaced quickly.
【００２３】焼成に用いる通気ガスは上記温度になし得
るものであれば特に限定されるものではなく、通常の燃
料ガスや燃料オイル等の燃焼による加熱空気、電気、熱
媒等による加熱空気、或いはこれらに水蒸気や還元ガ
ス、ＳＯｘガス等を添加したガスを用いてもよい。ま
た、水蒸気濃度が、露点で２０℃以下に調湿した通気ガ
スを用いる場合には特に比表面積が大きい遷移アルミナ
を得ることができるので推奨される。The ventilation gas used for firing is not particularly limited as long as it can reach the above temperature, and heating air by combustion of ordinary fuel gas or fuel oil, heating air by electricity, heat medium, or the like, or You may use the gas which added steam, reducing gas, SOx gas, etc. to these. Further, when an aeration gas whose moisture concentration is adjusted to 20 ° C. or less at the dew point is used, transition alumina having a large specific surface area can be obtained, which is recommended.
【００２４】上記した本発明方法によれば、初期比表面
積が約１５０ｍ2 ／ｇ以上、普通には約１５０ｍ2 ／ｇ
〜２５０ｍ2 ／ｇ、水蒸気濃度を上記範囲に調湿した通
気ガスを用いる場合には約２００ｍ2 ／ｇ以上であり、
１１００℃、３時間熱処理後の比表面積が１００ｍ2 ／
ｇ以上、普通には約１００ｍ2 ／ｇ〜１５０ｍ2 ／ｇの
遷移アルミナを得ることができる。According to the method of the present invention described above, the initial specific surface area is about 150 m 2 / g or more, usually about 150 m 2 / g.
˜250 m 2 / g, when using an aeration gas whose water vapor concentration is adjusted to the above range, it is about 200 m 2 / g or more,
The specific surface area after heat treatment at 1100 ° C. for 3 hours is 100 m 2 /
g or more, and usually can be obtained transition alumina of approximately 100m 2 / g~150m 2 / g.
【００２５】本発明において遷移アルミナとは、水酸化
アミニウム等を加熱し、θまたはαアルミナになる過程
の物を指し、具体的にはγ、δ、η、κ、χ等の結晶形
態を有する物であり、就中γ、δ、η晶の遷移アルミナ
である。これら遷移アルミナの結晶構造は分解後のアル
ミナの焼成温度や時間をコントロールすることにより容
易に得ることが可能である。In the present invention, the transition alumina refers to a substance in the process of heating aminium hydroxide or the like to form θ or α alumina, and specifically has a crystal form such as γ, δ, η, κ, χ. It is a transition alumina having γ, δ and η crystals. The crystal structure of these transition aluminas can be easily obtained by controlling the firing temperature and time of the alumina after decomposition.
【００２６】更に本発明方法に於いて、より高温での耐
熱性を改良する目的より、原料である硫酸アルミニウム
中に、該硫酸アルミニウム中のＡｌ原子をアルミナ（Ａ
ｌ2Ｏ3 ）に換算してアルミナ１００重量部に対してラ
ンタン原子換算で１〜１２重量部、好ましくは１〜１０
重量部の範囲になるようにランタン化合物を添加調合
し、これを本発明方法により乾燥した後、加熱（分解）
してもよい。Further, in the method of the present invention, for the purpose of improving the heat resistance at a higher temperature, the aluminum atom as a raw material is added to the aluminum sulfate (A).
1 to 12 parts by weight, preferably 1 to 10 parts by weight of lanthanum atom based on 100 parts by weight of alumina in terms of l 2 O 3 ).
The lanthanum compound was added and blended so as to be in the range of parts by weight, dried by the method of the present invention, and then heated (decomposed).
You may.
【００２７】アルミナ１００重量部に対するランタンの
添加量が１重量部より少ない場合には高温使用時の比表
面積低下抑制効果が十分でなく、他方添加量が多すぎる
場合には、１２００℃以上の温度での使用時に比表面積
の大幅な低下が起こる。If the amount of lanthanum added to 100 parts by weight of alumina is less than 1 part by weight, the effect of suppressing the decrease in the specific surface area at high temperature is not sufficient. When used in, the specific surface area is significantly reduced.
【００２８】ランタンの添加法は、製品としての遷移ア
ルミナ中にランタン化合物が存在していればよく特に制
限されるものではないが、例えば、ランタン化合物を硫
酸アルミニウム原料である水酸化アルミニウムに添加す
る方法、硫酸アルミニウムの水溶液にランタン化合物を
添加する方法、固体硫酸アルミニウムにランタン化合物
を分散した水溶液を添加する方法、焼成後得られた遷移
アルミナにランタン化合物水溶液を含浸し乾燥し、ラン
タン化合物をランタン酸化物に分解する方法等が挙げら
れるが、添加効果は原料である硫酸アルミニウムの熱分
解時にランタン化合物が存在している方が効果大であ
る。また得られる遷移アルミナの耐熱性の改良効果の点
から、ランタン化合物を添加する場合に適用する硫酸ア
ルミニウムは２０水塩以上の結晶水に相当する水を含有
するものを用いることが推奨される。The method for adding lanthanum is not particularly limited as long as the lanthanum compound is present in the transition alumina as a product, but for example, the lanthanum compound is added to aluminum hydroxide which is a raw material of aluminum sulfate. Method, method of adding lanthanum compound to aqueous solution of aluminum sulfate, method of adding aqueous solution of lanthanum compound dispersed in solid aluminum sulfate, impregnation of transition alumina obtained after firing with aqueous solution of lanthanum compound and drying, lanthanum compound to lanthanum Although a method of decomposing into an oxide can be mentioned, the effect of addition is more effective when a lanthanum compound is present at the time of thermal decomposition of aluminum sulfate as a raw material. From the viewpoint of improving the heat resistance of the obtained transition alumina, it is recommended that the aluminum sulfate used when adding the lanthanum compound contains water corresponding to crystallization water of 20 hydrate or more.
【００２９】本発明方法に於いて、硫酸アルミニウムに
安定化剤としてランタンを添加し得られた遷移アルミナ
は、細孔容積が約０．６ｃｃ／ｇ〜約２．０ｃｃ／ｇと
大きく、且つ初期比表面積が約１５０ｍ2 ／ｇ以上、普
通には約１５０ｍ2 ／ｇ〜約２５０ｍ2 ／ｇ、１１００
℃、３時間熱処理後の比表面積が約１００ｍ2 ／ｇ以
上、普通には約１００ｍ2 ／ｇ〜１５０ｍ2 ／ｇ、１２
００℃、３時間熱処理後の比表面積が約５０ｍ2 ／ｇ以
上、普通には約５０ｍ2 ／ｇ〜約１２０ｍ2 ／ｇの遷移
アルミナを得ることができる。In the method of the present invention, the transition alumina obtained by adding lanthanum as a stabilizer to aluminum sulfate has a large pore volume of about 0.6 cc / g to about 2.0 cc / g, and has an initial stage. the specific surface area of about 150 meters 2 / g or more, and usually about 150 meters 2 / g to about 250m 2 / g, 1100
° C., 3 hours the specific surface area after heat treatment of about 100 m 2 / g or more, and usually about 100m 2 / g~150m 2 / g, 12
00 ° C., it is the specific surface area following heat treatment for 3 hours is about 50 m 2 / g or more, and usually obtaining a transition alumina of approximately 50 m 2 / g to about 120 m 2 / g.
【００３０】このように本発明方法で得られた遷移アル
ミナは極めて大きい比表面積と、優れた耐熱性を有して
おり、そのままで、あるいは粉砕した後、触媒担体や樹
脂充填材として、或いは各種形状触媒担体成形用原料と
して使用される。さらにセラミック質あるいはメタルハ
ニカム等の既成形体表面に被覆するウォッシュコート用
組成物原料用アルミナとしても適用できる。As described above, the transition alumina obtained by the method of the present invention has an extremely large specific surface area and excellent heat resistance, and is used as it is or after crushing, as a catalyst carrier or resin filler, or in various types. Used as a raw material for molding shaped catalyst carriers. Further, it can also be applied as alumina for a raw material for a washcoat composition for coating the surface of an already formed body such as a ceramic material or a metal honeycomb.
【００３１】特に自動車排ガスの非選択脱硝反応用ある
いは完全酸化反応用のハニカム状貴金属触媒のウォッシ
ュコ−ト用組成物原料として適している。自動車排ガス
触媒として、本発明の遷移アルミナを適用する場合、公
知の方法でハニカムにウォッシュコ−トする前、或いは
ウォッシュコ−トした後、白金、ロジウム及びパラジウ
ムより選んだ貴金属を担持し触媒とすることも可能であ
る。更にウォッシュコ−トに際し本発明の遷移アルミナ
とセリアを混合してコ−トすることも可能である。この
ようにして得られた触媒は自動車排ガスコンバ−タ内に
取り付け、最高触媒温度が約９００〜１１００℃の条件
で使用することが可能である。In particular, it is suitable as a raw material for a wash coat of a honeycomb-shaped noble metal catalyst for non-selective denitration reaction of automobile exhaust gas or for complete oxidation reaction. When applying the transition alumina of the present invention as an automobile exhaust gas catalyst, before or after washcoating on a honeycomb by a known method, a precious metal selected from platinum, rhodium and palladium is supported as a catalyst. It is also possible to do so. It is also possible to mix the transition alumina of the present invention with ceria for the wash coating. The catalyst thus obtained can be installed in an automobile exhaust gas converter and used under conditions of a maximum catalyst temperature of about 900 to 1100 ° C.
【００３２】尚、白金、パラジウム、ロジウム、セリウ
ム、ジルコニウム、バリウム、ニッケル、銅、鉄等の触
媒成分を加熱分解前の硫酸アルミニウムに添加存在せし
めることも可能である。It is also possible to add a catalyst component such as platinum, palladium, rhodium, cerium, zirconium, barium, nickel, copper or iron to aluminum sulfate before thermal decomposition.
【００３３】[0033]
【発明の効果】以上詳述したごとく、本発明方法によれ
ば硫酸アルミニウムという廉価な原料を用い、簡単な原
料調整を行うことにより工業的焼成法を製品収率の低下
を招くことなく可能ならしめ、且つ得られる遷移アルミ
ナも、従来品に比較し、初期比表面積が大きく、高温
下、長時間の使用に於いても比表面積の低下の少ない耐
熱性に優れた遷移アルミナの提供を可能ならしめたもの
で、触媒或いは触媒担体等の分野においてその工業的価
値は頗る大なるものである。As described in detail above, according to the method of the present invention, if an inexpensive raw material of aluminum sulfate is used and a simple raw material adjustment is performed, an industrial firing method can be performed without lowering the product yield. In addition, the transition alumina obtained has a large initial specific surface area compared to conventional products, and it is possible to provide a transition alumina excellent in heat resistance with a small decrease in specific surface area even after long-term use at high temperature. It has a great industrial value in the field of catalysts or catalyst carriers.
【００３４】[0034]
【実施例】以下、本発明を実施例により更に詳細に説明
するが本発明は以下の実施例により制限される物ではな
い。EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to the following examples.
【００３５】尚、実施例においてＢＥＴ比表面積の測定
は窒素吸着法（測定温度７７Ｋ）で行った。また乾燥後
の硫酸アルミニウムの発泡程度は前記した基準充填密度
と補正後の試料の充填密度との比較より求めた。In the examples, the BET specific surface area was measured by the nitrogen adsorption method (measurement temperature 77K). The degree of foaming of aluminum sulfate after drying was determined by comparing the above-mentioned standard packing density with the packing density of the corrected sample.
【００３６】実施例１ 硫酸アルミニウム（住友化学工業株式会社製１７％品塊
状（中心粒径１０ｍｍ，Ａｌ2 （ＳＯ4 ）3 ・１４．３
Ｈ2 Ｏ）を１ｋｇ、アルミニウム製のバットに薄く広が
るように入れ、１１０℃のエアバスで乾燥した。乾燥中
１時間毎に重量を計ったところ、最大蒸発速度は有する
硫酸アルミニウムをＡｌ2 （ＳＯ4 ）3に換算して１ｇ
当たり、０．３ｍｇ／ｓｅｃで乾燥していた。２４時間
乾燥すると硫酸アルミニウムの結晶水に換算して７水塩
まで乾燥されていたので、乾燥を終了した。乾燥終了
後、乾燥品の総重量を測定した後、該乾燥品中より目視
で発泡している粒子を取り出して重量を計り、発泡品の
重量割合を求めた。その結果発泡率は２％であり実質的
に発泡していなかった。乾燥品の充填密度を測定したと
ころ０．７０ｃｃ／ｇであった。またこの試料の５００
℃脱水後の重量と５００℃脱水前の乾燥品重量の比は
０．７３であり補正後の試料の充填密度は０．５１ｇ／
ｃｃであった。次いで、乾燥品（観察した発泡品は元に
戻した）を２ｍｍ〜６．７ｍｍに篩別、調整し、この中
から１００ｇを無作為に採集し、内径７０ｍｍφ、長さ
１ｍのアルミナ製炉心管が垂直にセットされている環状
炉に、先ず１５ｍｍφのアルミナボ−ルを５０ｃｍ深さ
まで敷き、その上に乾燥品を供給した後、該乾燥品の中
央部に炉コントロ−ル用の熱電対を仕込み、更に乾燥品
の上から１５ｍｍφのアルミナボールを炉心管の上部ま
で仕込んだ。このようにして構成した炉心管の下部よ
り、露点が５０℃になるように調湿した空気を、炉心管
内の空塔線速度が０．３Ｎｍ／ｓｅｃに成るように導入
し、充填した硫酸アルミニウムを２５０℃／Ｈｒで８６
０℃まで昇温し、昇温後更に１６時間保持し焼成、熱分
解して遷移アルミナ（ｘ線回折の結果、大部分がγアル
ミナであった）を得た。焼成前後の重量より遷移アルミ
ナの回収率を求めたところ９８％であった。得られたア
ルミナの比表面積（初期比表面積）は１６２ｍ2 ／ｇで
あった。また得られた遷移アルミナ２ｇをアルミナ製坩
堝に入れマッフル炉中、露点１５℃の含水蒸気大気１．
５リットル／分の気流下で１１００℃、１２００℃の温
度で各３時間加熱して耐熱試験を行い、加熱後の比表面
積を測定した。この結果、１１００℃の温度で３時間加
熱後の比表面積は１２９ｍ2 ／ｇ、１２００℃の温度で
３時間加熱後の比表面積は２３ｍ2 ／ｇであった。[0036] Example 1 Aluminum sulfate (manufactured by Sumitomo Chemical Co., Ltd. 17% product mass (center particle diameter 10mm, Al 2 (SO 4) 3 · 14.3
1 kg of H 2 O) was placed in an aluminum vat so as to spread thinly and dried in an air bath at 110 ° C. When weighed every hour during drying, the maximum evaporation rate was 1 g of aluminum sulfate, which had been converted to Al 2 (SO 4 ) 3.
Therefore, it was dried at 0.3 mg / sec. When it was dried for 24 hours, it was converted to water of crystallization of aluminum sulfate up to the heptahydrate, so the drying was completed. After the completion of the drying, the total weight of the dried product was measured, and then the foamed particles were taken out from the dried product and weighed to determine the weight ratio of the foamed product. As a result, the foaming rate was 2%, and substantially no foaming occurred. The packing density of the dried product was measured and found to be 0.70 cc / g. Also 500 of this sample
The ratio of the weight after dehydration at 0 ° C and the weight of dried product before dehydration at 500 ° C was 0.73, and the packing density of the corrected sample was 0.51 g /
It was cc. Next, the dried product (the observed foamed product was returned to the original) was sieved and adjusted to 2 mm to 6.7 mm, and 100 g was randomly collected from this, and an alumina core tube with an inner diameter of 70 mmφ and a length of 1 m was collected. First, a 15 mmφ alumina ball was laid to a depth of 50 cm in an annular furnace in which the vertical axis was set to 50 cm, a dry product was supplied on the alumina ball, and a thermocouple for the furnace control was placed in the center of the dry product. Further, 15 mmφ alumina balls were charged from the dried product to the upper part of the furnace core tube. From the lower portion of the thus constructed core tube, air whose humidity was adjusted to a dew point of 50 ° C. was introduced so that the superficial linear velocity in the core tube was 0.3 Nm / sec, and aluminum sulfate was charged. 86 at 250 ° C / Hr
The temperature was raised to 0 ° C., and after the temperature was raised, the temperature was maintained for another 16 hours, followed by firing and thermal decomposition to obtain transition alumina (most of which was γ alumina as a result of x-ray diffraction). The recovery rate of transition alumina was calculated from the weight before and after firing, and was 98%. The specific surface area (initial specific surface area) of the obtained alumina was 162 m 2 / g. Further, 2 g of the obtained transition alumina was placed in an alumina crucible and in a muffle furnace, a steam-containing atmosphere having a dew point of 15 ° C. 1.
A heat resistance test was conducted by heating at a temperature of 1100 ° C. and 1200 ° C. for 3 hours under an air flow of 5 liter / min, and the specific surface area after heating was measured. As a result, the specific surface area after heating at 1100 ° C. for 3 hours was 129 m 2 / g, and the specific surface area after heating at 1200 ° C. for 3 hours was 23 m 2 / g.
【００３７】実施例２ 実施例１において、１７％硫酸アルミニウムの乾燥を、
１２０℃のエアバスで乾燥した。乾燥中１時間毎に重量
を計ったところ、最大蒸発速度は有する硫酸アルミニウ
ムをＡｌ2 （ＳＯ4 ）3 に換算して１ｇ当たり、１．７
ｍｇ／ｓｅｃで乾燥していた。２４時間乾燥すると硫酸
アルミニウムの結晶水に換算して６水塩まで乾燥されて
いたので、乾燥を終了した。この乾燥品の中から発泡し
ている粒子を取り出して重量を計り、乾燥取り出し重量
から割合を求めると、８％であった。乾燥品の充填密度
を測定したところ０．６２ｃｃ／ｇであった。またこの
試料の５００℃脱水後の重量と５００℃脱水前の乾燥品
重量の比は０．７６であり補正後の試料の充填密度は
０．４７ｇ／ｃｃであった。発泡品を戻した乾燥品を、
実施例１と同様の焼成、熱分解して遷移アルミナを得
た。焼成前後の重量より、遷移アルミナの回収率を求め
ると、９２％であった。また、得られた遷移アルミナを
実施例１と同様の方法で比表面積を測定したところ、初
期比表面積は１５６ｍ2 ／ｇ、１１００℃の温度で３時
間加熱後の比表面積は１３０ｍ2 ／ｇ、１２００℃の温
度で３時間加熱後の比表面積は１７ｍ2／ｇであった。Example 2 In Example 1, drying of 17% aluminum sulfate was performed.
It was dried in an air bath at 120 ° C. When weighed every hour during drying, the maximum evaporation rate was 1.7% per 1 g of aluminum sulfate converted to Al 2 (SO 4 ) 3.
It was dry at mg / sec. When it was dried for 24 hours, it was converted to water of crystallization of aluminum sulfate up to the hexahydrate, so the drying was terminated. The foamed particles were taken out from the dried product, weighed, and the ratio was calculated from the dry taken-out weight, and it was 8%. The packing density of the dried product was measured and found to be 0.62 cc / g. The ratio of the weight of this sample after dehydration at 500 ° C. to the weight of dried product before dehydration at 500 ° C. was 0.76, and the packing density of the sample after correction was 0.47 g / cc. The dried product which returned the foamed product,
The same firing and thermal decomposition as in Example 1 were performed to obtain transition alumina. The recovery rate of transition alumina was calculated from the weight before and after firing, and was found to be 92%. Further, when the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 156 m 2 / g, the specific surface area after heating at a temperature of 1100 ° C. for 3 hours was 130 m 2 / g, The specific surface area after heating for 3 hours at a temperature of 1200 ° C. was 17 m 2 / g.
【００３８】実施例３ 実施例１の方法に於いて、熱分解時、露点を５０℃に調
湿した空気に換えて露点が−３５℃になるように乾燥し
た空気を用いた他は実施例１と全く同様にして遷移アル
ミナを得た。得られた遷移アルミナを実施例１と同様の
方法で比表面積を測定したところ、初期比表面積は２２
５ｍ2 ／ｇ、１１００℃の温度で３時間加熱後の比表面
積は１０２ｍ2 ／ｇ、１２００℃の温度で３時間加熱後
の比表面積は１３ｍ2 ／ｇであった。Example 3 In the same manner as in Example 1, except that during the thermal decomposition, the air whose dew point was adjusted to 50 ° C. was replaced with dry air having a dew point of −35 ° C. Transition alumina was obtained in exactly the same manner as in 1. When the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 22.
The specific surface area after heating at a temperature of 5 m 2 / g and 1100 ° C. for 3 hours was 102 m 2 / g, and the specific surface area after heating at a temperature of 1200 ° C. for 3 hours was 13 m 2 / g.
【００３９】実施例４ 実施例１の方法に於いて、熱分解時の炉心管の下部より
炉心管内に導入する空気の空塔線速度を０．３Ｎｍ／ｓ
ｅｃから１．２８Ｎｍ／ｓｅｃに換え、かつ露点を５０
℃に調湿した空気に換えて露点が−３５℃になるように
乾燥した空気を用いた他は実施例１と全く同様にして遷
移アルミナを得た。得られた遷移アルミナを実施例１と
同様の方法で比表面積を測定したところ、初期比表面積
は２２７ｍ2 ／ｇ、１１００℃の温度で３時間加熱後の
比表面積は７５ｍ2 ／ｇ、１２００℃の温度で３時間加
熱後の比表面積は１０ｍ2 ／ｇであった。Example 4 In the method of Example 1, the superficial linear velocity of air introduced into the core tube from the lower part of the core tube at the time of thermal decomposition was 0.3 Nm / s.
ec to 1.28 Nm / sec and dew point 50
A transition alumina was obtained in exactly the same manner as in Example 1 except that the air whose temperature was adjusted to ℃ was replaced by the air which was dried to have a dew point of −35 ° C. When the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 227 m 2 / g, the specific surface area after heating at a temperature of 1100 ° C. for 3 hours was 75 m 2 / g, 1200 ° C. The specific surface area after heating for 3 hours at 10 m 2 / g was 10 m 2 / g.
【００４０】実施例５ Ｆｅ，Ｎａ，Ｋ，Ｃａ，Ｓｉ，Ｍｇのト−タルが１０ｐ
ｐｍ以下の粉状結晶硫酸アルミニウム１ｋｇを皿径が７
０ｃｍの転動造粒装置でイオン水をスプレ−しながら中
心粒径が１０ｍｍに成るように造粒した。この造粒品は
硫酸アルミニウムの結晶水に換算して２０水塩に相当す
る水を含有していた。この造粒品を１１０℃のエアバス
で乾燥した。乾燥中１時間毎に重量を計ったところ、最
大蒸発速度は硫酸アルミニウムをＡｌ2 （ＳＯ4 ）3 に
換算して１ｇ当たり、０．３ｍｇ／ｓｅｃで乾燥してい
た。３０時間乾燥すると硫酸アルミニウムの結晶水に換
算して６水塩まで乾燥されたので、乾燥を終了した。こ
の乾燥品中に占める発泡品の割合は２％であった。乾燥
品の充填密度を測定したところ０．６７ｃｃ／ｇであっ
た。またこの試料の５００℃脱水後の重量と５００℃脱
水前の乾燥品重量の比は０．７６であり補正後の試料の
充填密度は０．５１ｇ／ｃｃであった。得られた乾燥品
を実施例１と同様の方法で焼成、熱分解して遷移アルミ
ナを得た。この方法に於ける遷移アルミナの回収率は９
８％であった。得られた遷移アルミナを実施例１と同様
の方法で比表面積を測定したところ、初期比表面積は１
５２ｍ2 ／ｇ、１１００℃の温度で３時間加熱後の比表
面積は１３６ｍ2 ／ｇ、１２００℃の温度で３時間加熱
後の比表面積は５７ｍ2 ／ｇであった。Example 5 Total of Fe, Na, K, Ca, Si and Mg is 10 p.
1 kg of powdery crystalline aluminum sulphate of pm or less with a dish diameter of 7
While ionic water was sprayed with a 0 cm tumbling granulator, granulation was carried out so that the central particle size became 10 mm. This granulated product contained water corresponding to 20-hydrate in terms of crystal water of aluminum sulfate. This granulated product was dried in an air bath at 110 ° C. When the weight was measured every hour during drying, the maximum evaporation rate was 0.3 mg / sec per 1 g of aluminum sulfate converted to Al 2 (SO 4 ) 3 . When it was dried for 30 hours, it was converted to water of crystallization of aluminum sulfate to be dried up to hexahydrate, so the drying was finished. The proportion of the foamed product in this dried product was 2%. The packing density of the dried product was measured and found to be 0.67 cc / g. The ratio of the weight of this sample after dehydration at 500 ° C. to the weight of dried product before dehydration at 500 ° C. was 0.76, and the packing density of the sample after correction was 0.51 g / cc. The obtained dried product was baked and pyrolyzed in the same manner as in Example 1 to obtain transition alumina. The recovery rate of transition alumina in this method is 9
It was 8%. When the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 1
The specific surface area after heating at 52 m 2 / g and a temperature of 1100 ° C. for 3 hours was 136 m 2 / g and the specific surface area after heating at a temperature of 1200 ° C. for 3 hours was 57 m 2 / g.
【００４１】実施例６ ２リットルビ−カ−に、市販の液体硫酸アルミニウム
（住友化学工業株式会社製、硫酸アルミニウム濃度２７
％）５００ｇと、原料硫酸アルミニウム中のアルミナ１
００重量部当たりランタン元素として３．０重量部とな
る量の酢酸ランタンを仕込み、室温で３０分撹拌しなが
ら十分溶解させた。この溶液を１２０℃のエアバスで硫
酸アルミニウムの結晶水に換算して６水塩まで乾燥し
た。乾燥中１時間毎に重量を計ったところ、最大蒸発速
度は有する硫酸アルミニウムをＡｌ2 （ＳＯ4 ）3 に換
算して１ｇ当たり、０．３ｍｇ／ｓｅｃで乾燥してい
た。この乾燥品は、ビ−カ−の形のまま収縮した状態で
乾燥しており、発泡していなかった。この乾燥品をハン
マ−で解砕し、中心粒径が１ｃｍになるようにした。乾
燥品の充填密度を測定したところ０．７０ｃｃ／ｇであ
った。またこの試料の５００℃脱水後の重量と５００℃
脱水前の乾燥品重量の比は０．７６であり補正後の試料
の充填密度は０．５３ｇ／ｃｃであった。実施例１と同
様方法で熱分解し遷移アルミナを得た。この方法による
遷移アルミナの回収率は１００％であった。得られた遷
移アルミナを実施例１と同様の方法で比表面積を測定し
たところ、初期比表面積は１５３ｍ2 ／ｇ、１１００℃
の温度で３時間加熱後の比表面積は１２８ｍ2 ／ｇ、１
２００℃の温度で３時間加熱後の比表面積は７４ｍ2 ／
ｇであった。Example 6 A commercially available liquid aluminum sulfate (manufactured by Sumitomo Chemical Co., Ltd., aluminum sulfate concentration 27) was added to a 2-liter beaker.
%) 500 g, and alumina 1 in the raw material aluminum sulfate.
Lanthanum acetate in an amount of 3.0 parts by weight as lanthanum element per 00 parts by weight was charged and sufficiently dissolved with stirring at room temperature for 30 minutes. This solution was converted into aluminum sulfate water of crystallization by an air bath at 120 ° C. and dried to hexahydrate. When the weight was measured every hour during drying, it was found that aluminum sulfate having a maximum evaporation rate was converted into Al 2 (SO 4 ) 3 and dried at 0.3 mg / sec per 1 g. The dried product was dried in a contracted state in the form of a beaker and was not foamed. The dried product was crushed with a hammer so that the central particle size became 1 cm. The packing density of the dried product was measured and found to be 0.70 cc / g. The weight of this sample after dehydration at 500 ° C and 500 ° C
The ratio of the dry product weight before dehydration was 0.76, and the corrected packing density of the sample was 0.53 g / cc. Pyrolysis was performed in the same manner as in Example 1 to obtain transition alumina. The recovery rate of transition alumina by this method was 100%. When the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 153 m 2 / g, 1100 ° C.
Specific surface area after heating for 3 hours at 128m 2 / g, 1
The specific surface area after heating at a temperature of 200 ° C. for 3 hours is 74 m 2 /
It was g.
【００４２】実施例７ 実施例６と同様の方法に於いて、原料硫酸アルミニウム
中のアルミナ１００重量部当たりランタン元素として１
２重量部となるように酢酸ランタンを仕込んだ。この溶
液を実施例６と同じ方法で、乾燥、解砕、焼成・熱分解
を行い遷移アルミナを得た。得られた遷移アルミナを実
施例１と同様の方法で比表面積を測定したところ、初期
比表面積は１５１ｍ2 ／ｇ、１１００℃の温度で３時間
加熱後の比表面積は１０１ｍ2 ／ｇ、１２００℃の温度
で３時間加熱後の比表面積は５３ｍ2 ／ｇであった。Example 7 In the same manner as in Example 6, 1 lanthanum element was added per 100 parts by weight of alumina in the raw material aluminum sulfate.
Lanthanum acetate was charged so as to be 2 parts by weight. This solution was dried, crushed, calcined and pyrolyzed in the same manner as in Example 6 to obtain transition alumina. When the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 151 m 2 / g, the specific surface area after heating at a temperature of 1100 ° C. for 3 hours was 101 m 2 / g, 1200 ° C. The specific surface area after heating at a temperature of 3 hours for 3 hours was 53 m 2 / g.
【００４３】比較例１ 実施例１と同様の方法で得られた乾燥品を、内径７ｃｍ
φで高さが１０ｃｍのアルミナ坩堝に４ｃｍ層高になる
ように入れ、箱形のマッフル炉で室温から２５０℃／Ｈ
ｒで昇温し８５０℃で、分解ガスが発生しなくなるまで
焼成・熱分解し遷移アルミナを得た。分解終了するまで
９３時間を必要とした。得られた遷移アルミナを実施例
１と同様の方法で比表面積を測定したところ、初期比表
面積は１３３ｍ2 ／ｇ、１１００℃の温度で３時間加熱
後の比表面積は１３１ｍ2 ／ｇ、１２００℃の温度で３
時間加熱後の比表面積は３３ｍ2 ／ｇであった。COMPARATIVE EXAMPLE 1 A dried product obtained by the same method as in Example 1 had an inner diameter of 7 cm.
It is put into an alumina crucible with a height of 10 cm and a height of 4 cm, and it is heated from room temperature to 250 ° C / H in a box-shaped muffle furnace.
The temperature was raised at r and the temperature was raised to 850 ° C., and the alumina was calcined and thermally decomposed until no decomposition gas was generated to obtain transition alumina. It took 93 hours to complete the decomposition. When the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 133 m 2 / g, the specific surface area after heating at a temperature of 1100 ° C. for 3 hours was 131 m 2 / g, 1200 ° C. At the temperature of 3
The specific surface area after the time heating was 33 m 2 / g.
【００４４】比較例２ 実施例６と同様の方法で得られたランタン化合物を含む
乾燥品を、内径７ｃｍφで高さが１０ｃｍのアルミナ坩
堝に４ｃｍ層高になるように入れ、箱形のマッフル炉で
室温から２５０℃／Ｈｒで昇温し８５０℃で、分解ガス
が発生しなくなるまで焼成・熱分解し遷移アルミナを得
た。分解終了するまで９３時間を必要とした。得られた
遷移アルミナを実施例１と同様の方法で比表面積を測定
したところ、初期比表面積は１２８ｍ2 ／ｇ、１１００
℃の温度で３時間加熱後の比表面積は１０７ｍ2 ／ｇ、
１２００℃の温度で３時間加熱後の比表面積は７０ｍ2
／ｇであった。Comparative Example 2 A dried product containing a lanthanum compound obtained in the same manner as in Example 6 was placed in an alumina crucible having an inner diameter of 7 cmφ and a height of 10 cm so that the layer height was 4 cm, and a box-shaped muffle furnace was used. The temperature was raised from room temperature to 250 ° C./Hr at 850 ° C., and calcined and thermally decomposed until no decomposition gas was generated to obtain transition alumina. It took 93 hours to complete the decomposition. When the specific surface area of the obtained transition alumina was measured by the same method as in Example 1, the initial specific surface area was 128 m 2 / g, 1100.
The specific surface area after heating at a temperature of ℃ for 3 hours is 107 m 2 / g,
The specific surface area after heating at 1200 ° C for 3 hours is 70m 2
/ G.
【００４５】比較例３ 実施例１において、１７％硫酸アルミニウムの乾燥を、
１４０℃のエアバスで実施した。乾燥中１時間毎に重量
を計ったところ、最大蒸発速度は有する硫酸アルミニウ
ムをＡｌ2 （ＳＯ4 ）3 に換算して１ｇ当たり、２．４
ｍｇ／ｓｅｃであった。２４時間乾燥すると硫酸アルミ
ニウムの結晶水に換算して５水塩まで乾燥されていたの
で、乾燥を終了した。この乾燥品の中から発泡率を実施
例１と同様の方法で測定したところ３０％であった。乾
燥品の充填密度を測定したところ０．４０ｃｃ／ｇであ
った。またこの試料の５００℃脱水後の重量と５００℃
脱水前の乾燥品重量の比は０．７９であり補正後の試料
の充填密度は０．３２ｇ／ｃｃであった。得られた乾燥
品を、実施例１と同じ方法で焼成、熱分解し遷移アルミ
ナを得た。この方法に於ける遷移アルミナの回収率は７
０％であり、発泡していた粒子が飛散消失していること
が判った。Comparative Example 3 In Example 1, drying of 17% aluminum sulfate was performed.
It was carried out in an air bath at 140 ° C. When the weight was measured every hour during drying, the maximum evaporation rate was 2.4 per 1 g of aluminum sulfate converted into Al 2 (SO 4 ) 3.
It was mg / sec. When it was dried for 24 hours, it was converted to water of crystallization of aluminum sulfate up to the pentahydrate, so the drying was terminated. The foaming ratio of this dried product was measured by the same method as in Example 1, and it was 30%. When the packing density of the dried product was measured, it was 0.40 cc / g. The weight of this sample after dehydration at 500 ° C and 500 ° C
The ratio of the dry product weight before dehydration was 0.79, and the corrected packing density of the sample was 0.32 g / cc. The obtained dried product was baked and pyrolyzed in the same manner as in Example 1 to obtain transition alumina. The recovery rate of transition alumina in this method is 7
It was 0%, and it was found that the foamed particles were scattered and disappeared.
【００４６】比較例４ 実施例１において、１７％硫酸アルミニウムの乾燥を、
１１０℃のエアバスで乾燥した。乾燥中１時間毎に重量
を計り、硫酸アルミニウムの結晶水に換算して１０水塩
になったところで乾燥を終了した。最大蒸発速度は有す
る硫酸アルミニウムをＡｌ2 （ＳＯ4 ）3 に換算して１
ｇ当たり、０．３ｍｇ／ｓｅｃで乾燥していた。乾燥品
の発泡率は２％であった。乾燥品の充填密度を測定した
ところ０．７７ｃｃ／ｇであった。またこの試料の５０
０℃脱水後の重量と５００℃脱水前の乾燥品重量の比は
０．６６であり補正後の試料の充填密度は０．５１ｇ／
ｃｃであった。得られた乾燥品を、実施例１と同じ方法
で焼成、熱分解し遷移アルミナを得た。この方法に於け
る遷移アルミナの回収率は８５％であり、熱分解時粒子
が飛散消失していることが判った。Comparative Example 4 In Example 1, drying of 17% aluminum sulfate was carried out.
It was dried in an air bath at 110 ° C. The weight was measured every hour during the drying, and the drying was completed when 10 hydrates were calculated in terms of the water of crystallization of aluminum sulfate. The maximum evaporation rate is 1 when converting the aluminum sulphate it has to Al 2 (SO 4 ) 3.
It was dried at 0.3 mg / sec per g. The foaming rate of the dried product was 2%. When the packing density of the dried product was measured, it was 0.77 cc / g. Also 50 of this sample
The ratio of the weight after dehydration at 0 ° C. and the weight of dried product before dehydration at 500 ° C. was 0.66, and the packing density of the corrected sample was 0.51 g /
It was cc. The obtained dried product was baked and pyrolyzed in the same manner as in Example 1 to obtain transition alumina. The recovery rate of the transition alumina in this method was 85%, and it was found that the particles were scattered and disappeared during the thermal decomposition.
【００４７】比較例５ 実施例１において、焼成（熱分解）に内径７０ｍｍ，長
さ１ｍの回転機能を有するアルミナ製炉心管で内部に厚
さ１ｃｍ、炉内壁よりの高さ１ｃｍの堰を２個有する外
熱式ロータリー炉を用い、この堰間に乾燥品１００ｇを
供給した他は、実施例１と全く同様に乾燥、熱分解し遷
移アルミナを得た。得られた遷移アルミナはＸ線回折の
結果、大部分がγアルミナであり、また遷移アルミナの
回収率は６９％であった。Comparative Example 5 In Example 1, an alumina core tube having an inner diameter of 70 mm and a length of 1 m, which has a rotating function and has a thickness of 1 cm and a weir having a height of 1 cm from the inner wall of the furnace were used for firing (pyrolysis). An externally heated rotary furnace was used, and 100 g of a dried product was supplied between the weirs, and the same drying and thermal decomposition as in Example 1 was performed to obtain transition alumina. As a result of X-ray diffraction, the obtained transition alumina was mostly γ-alumina, and the transition alumina recovery rate was 69%.
Claims (5)
水塩を越える水を含有する硫酸アルミニウムを、硫酸ア
ルミニウム〔Ａｌ2 （ＳＯ4 ）3 として〕１ｇ当たりか
らの水の蒸発速度が０．０１ｍｇ／ｓｅｃ〜２．０ｍｇ
／ｓｅｃで８水塩以下の結晶水に相当する水含有量の硫
酸アルミニウムとなるまで乾燥し、該乾燥後の硫酸アル
ミニウムを必要に応じて６水塩以下の結晶水に相当する
水含有量の硫酸アルミニウムとなるまで乾燥した後、該
乾燥後の６水塩以下の結晶水に相当する水含有量の硫酸
アルミニウムを竪型気流接触式焼成炉に供給し、該焼成
炉中で熱分解し遷移アルミナを得ることを特徴とする硫
酸アルミニウムからの遷移アルミナの製造方法。1. Amount of crystallization of aluminum sulfate of 8
The evaporation rate of water per 1 g of aluminum sulfate [as Al 2 (SO 4 ) 3 ] containing water exceeding water salt is 0.01 mg / sec to 2.0 mg.
/ Sec to obtain aluminum sulfate having a water content corresponding to crystal water of 8 hydrate or less, and the aluminum sulfate after the drying is, if necessary, a water content corresponding to crystal water of 6 hydrate or less. After drying until it becomes aluminum sulfate, aluminum sulfate having a water content corresponding to the water of crystallization of the hexahydrate or less after the drying is supplied to a vertical airflow contact type firing furnace, and pyrolyzed and transitioned in the firing furnace. A method for producing transition alumina from aluminum sulfate, which comprises obtaining alumina.
水塩を越える水を含有する硫酸アルミニウムが、硫酸ア
ルミニウム中のＡｌ原子をアルミナ（Ａｌ2Ｏ3 ）に換
算してアルミナ１００重量部に対してランタン原子換算
で１〜１２重量部よりなるランタン化合物を含有するこ
とを特徴とする、請求項１記載の硫酸アルミニウムから
の遷移アルミナの製造方法。2. It is 8 in terms of crystal water of aluminum sulfate.
A lanthanum compound in which aluminum sulfate containing water in excess of hydrate is 1 to 12 parts by weight in terms of lanthanum atom based on 100 parts by weight of alumina by converting Al atoms in aluminum sulfate into alumina (Al 2 O 3 ). The method for producing a transition alumina from aluminum sulfate according to claim 1, which comprises:
と接触通過する気流の空塔線速度が、０．０１Ｎｍ／ｓ
〜１．０Ｎｍ／ｓであることを特徴とする請求項１また
は２記載の硫酸アルミニウムからの遷移アルミナの製造
方法。3. The superficial linear velocity of the air stream which is passed through in contact with aluminum sulfate in the firing furnace during the thermal decomposition is 0.01 Nm / s.
It is -1.0 Nm / s, The manufacturing method of the transition alumina from the aluminum sulfate of Claim 1 or 2 characterized by the above-mentioned.
と接触通過する気流の水蒸気濃度が、露点表示で２０℃
以下である請求項１〜３のいずれかに記載の硫酸アルミ
ニウムからの遷移アルミナの製造方法。4. The vapor concentration of an air stream passing through in contact with aluminum sulfate in a firing furnace during thermal decomposition is 20 ° C. in dew point display.
It is the following, The manufacturing method of the transition alumina from the aluminum sulfate in any one of Claims 1-3.
水に相当する水を含有するものであることを特徴とす
る、請求項２に記載の硫酸アルミニウムからの遷移アル
ミナの製造方法。5. The method for producing transition alumina from aluminum sulfate according to claim 2, wherein the aluminum sulfate contains water corresponding to water of crystallization of 20 hydrates or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7036932A JPH07291622A (en) | 1994-02-28 | 1995-02-24 | Production of transition alumina from aluminum sulfate |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6-30064 | 1994-02-28 | ||
| JP3006494 | 1994-02-28 | ||
| JP7036932A JPH07291622A (en) | 1994-02-28 | 1995-02-24 | Production of transition alumina from aluminum sulfate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07291622A true JPH07291622A (en) | 1995-11-07 |
Family
ID=26368335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7036932A Pending JPH07291622A (en) | 1994-02-28 | 1995-02-24 | Production of transition alumina from aluminum sulfate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07291622A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110492789A (en) * | 2019-07-30 | 2019-11-22 | 北京理工大学 | A kind of water evaporation electricity production device and preparation method thereof based on aluminum oxide nano coating |
| CN112209414A (en) * | 2020-09-01 | 2021-01-12 | 靖西天桂铝业有限公司 | Linkage hot test process before production of aluminum oxide |
-
1995
- 1995-02-24 JP JP7036932A patent/JPH07291622A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110492789A (en) * | 2019-07-30 | 2019-11-22 | 北京理工大学 | A kind of water evaporation electricity production device and preparation method thereof based on aluminum oxide nano coating |
| CN112209414A (en) * | 2020-09-01 | 2021-01-12 | 靖西天桂铝业有限公司 | Linkage hot test process before production of aluminum oxide |
| CN112209414B (en) * | 2020-09-01 | 2022-11-11 | 靖西天桂铝业有限公司 | Linkage hot test process before alumina production |
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