JPH0132169B2 - - Google Patents
Info
- Publication number
- JPH0132169B2 JPH0132169B2 JP57177838A JP17783882A JPH0132169B2 JP H0132169 B2 JPH0132169 B2 JP H0132169B2 JP 57177838 A JP57177838 A JP 57177838A JP 17783882 A JP17783882 A JP 17783882A JP H0132169 B2 JPH0132169 B2 JP H0132169B2
- Authority
- JP
- Japan
- Prior art keywords
- alumina
- pseudo
- boehmite
- hours
- hydrogel
- 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.)
- Expired
Links
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 99
- VXAUWWUXCIMFIM-UHFFFAOYSA-M aluminum;oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Al+3] VXAUWWUXCIMFIM-UHFFFAOYSA-M 0.000 claims description 35
- 238000000034 method Methods 0.000 claims description 29
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 22
- 239000000017 hydrogel Substances 0.000 claims description 21
- 239000011148 porous material Substances 0.000 claims description 21
- 239000000126 substance Substances 0.000 claims description 20
- 239000013078 crystal Substances 0.000 claims description 17
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 229910001388 sodium aluminate Inorganic materials 0.000 claims description 13
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 claims description 10
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical group [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 claims description 9
- 238000001694 spray drying Methods 0.000 claims description 9
- 239000000499 gel Substances 0.000 claims description 8
- QAOWNCQODCNURD-UHFFFAOYSA-L sulfate group Chemical group S(=O)(=O)([O-])[O-] QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 5
- 238000001354 calcination Methods 0.000 claims 2
- 239000000843 powder Substances 0.000 description 29
- 239000007864 aqueous solution Substances 0.000 description 27
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 20
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 18
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 17
- 238000001035 drying Methods 0.000 description 16
- 238000002347 injection Methods 0.000 description 13
- 239000007924 injection Substances 0.000 description 13
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 12
- 239000008367 deionised water Substances 0.000 description 12
- 229910021641 deionized water Inorganic materials 0.000 description 12
- 239000002245 particle Substances 0.000 description 10
- 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 9
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 8
- 238000010304 firing Methods 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 230000014759 maintenance of location Effects 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- 235000011121 sodium hydroxide Nutrition 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 239000003960 organic solvent Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- SZIFAVKTNFCBPC-UHFFFAOYSA-N 2-chloroethanol Chemical compound OCCCl SZIFAVKTNFCBPC-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 229910001593 boehmite Inorganic materials 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 210000003298 dental enamel Anatomy 0.000 description 2
- 239000012065 filter cake Substances 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 150000003944 halohydrins Chemical class 0.000 description 2
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- GJPYYNMJTJNYTO-UHFFFAOYSA-J sodium aluminium sulfate Chemical compound [Na+].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GJPYYNMJTJNYTO-UHFFFAOYSA-J 0.000 description 2
- 239000011550 stock solution Substances 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- BPLYVSYSBPLDOA-GYOJGHLZSA-N n-[(2r,3r)-1,3-dihydroxyoctadecan-2-yl]tetracosanamide Chemical compound CCCCCCCCCCCCCCCCCCCCCCCC(=O)N[C@H](CO)[C@H](O)CCCCCCCCCCCCCCC BPLYVSYSBPLDOA-GYOJGHLZSA-N 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 235000011118 potassium hydroxide Nutrition 0.000 description 1
- KVOIJEARBNBHHP-UHFFFAOYSA-N potassium;oxido(oxo)alumane Chemical compound [K+].[O-][Al]=O KVOIJEARBNBHHP-UHFFFAOYSA-N 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- PANBYUAFMMOFOV-UHFFFAOYSA-N sodium;sulfuric acid Chemical compound [Na].OS(O)(=O)=O PANBYUAFMMOFOV-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
Classifications
-
- 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
- C01F7/44—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water
- C01F7/441—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water by calcination
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/14—Aluminium oxide or hydroxide from alkali metal aluminates
- C01F7/141—Aluminium oxide or hydroxide from alkali metal aluminates from aqueous aluminate solutions by neutralisation with an acidic agent
-
- 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
- C01F7/34—Preparation of aluminium hydroxide by precipitation from solutions containing aluminium salts
Description
本発明は、低嵩密度のアルミナ粉末、殊に、高
表面積、高細孔容積及び低嵩密度を有しかつ高吸
油量を示すアルミナ粉末を工業的に有利に製造す
る方法に関するものである。
γ−アルミナや、δないしθ−アルミナは、擬
ベーマイトの脱水転移生成物であり、吸着剤、添
加剤、保持剤、触媒、触媒担体、成形助剤、コー
テイング剤等の非常に広範な用途を持つている。
これらの多くの用途は、アルミナの多孔性、吸水
性、吸油性、吸着性、嵩密度、保水性、保油性、
純度等に起因する。従つて、アルミナの細孔容
積、表面積、嵩密度を特定の好ましい範囲、特に
高細孔容積、高表面積、低嵩密度にもつていくこ
とが望まれている。
このようなアルミナの製造法としては、大別す
ると、気相生成法とヒドロゲル生成法がある。気
相生成法は、金属アルミニウムの酸化や、塩化ア
ルミニウムの熱分解反応を含むが、その製造法に
は著しい困難が伴う上、製造コストが高いという
欠点がある。一方、ヒドロゲル生成法は、擬ベー
マイトをいつたん生成させ、これを乾燥、焼成す
ることによつて多孔性アルミナを得る方法であ
る。そして、この方法に関しては、乾燥、焼成過
程におけるゲル構造の収縮度を調節することによ
つて、得られるアルミナの物性を制御しようとす
る方法が提案されており、例えば、ベーマイトゲ
ルの乾燥速度を変化せしめる方法、ベーマイトゲ
ル中の水の一部又は大部分をアルコール等の有機
溶剤で置換する方法等があるが、これらの方法で
得られるアルミナは、低細孔容積、高嵩密度とな
ると共に、耐水性に乏しく、その上その製造コス
トが高くなるという傾向がある。特公昭57−
13496号公報によれば、アルミン酸アルカリと、
エチレンクロルヒドリン等のハロヒドリンとの反
応によつて特殊な擬ベーマイト生成させ、これを
用いて高表面積、低嵩比重を持つアルミナの製造
方法が提案されている。しかしながら、この方法
も、エチレンクロルヒドリン等の高価なハロヒド
リンを使用するために製造コストが高くなるとい
う欠点を有する。
本発明者らは、高表面積、高細孔容積及び低嵩
密度のアルミナを工業的に有利に製造し得る方法
を開発すべく鋭意研究を重ねた結果、本発明を完
成するに到つた。
即ち、本発明によれば、PH６〜11、50℃以上の
条件下で形成されたアルミナヒドロゲルに、アル
ミナヒドロゲル形成物質を、擬ベーマイト生成条
件下及び硫酸根の共存下で添加し、結晶成長し、
疎凝集体を形成する擬ベーマイトゲルを得ると共
に、この擬ベーマイトゲルを水洗後、噴霧乾燥
し、焼成することにより、細孔容積２〜５ml／
ｇ、表面積150〜300m2／ｇ及び嵩密度0.10〜0.25
ｇ／mlのアルミナを生成させることを特徴とする
アルミナの製造方法が提供される。
本発明の方法は、特殊の擬ベーマイトの形成工
程と、形成されたゲルの洗浄、乾燥、焼成を行う
アルミナ形成工程から成り立つている。擬ベーマ
イト形成工程においては、アルミナヒドロゲル形
成物質を原料として用い、PH６〜11、50℃以上の
条件下でアルミナヒドロゲル、いわゆる結晶成長
における種子ゲル（以下、出発時のアルミナヒド
ロゲルと呼ぶ）を形成し、このアルミナヒドロゲ
ルを種子として用い、この種子アルミナヒドロゲ
ルに対して、さらにアルミナヒドロゲル形成物質
を、擬ベーマイト生成条件下、実質的に硫酸根が
共存する状態で添加し、最終的に結晶成長し、か
つ疎凝集体を形成する擬ベーマイトを形成させ
る。
アルミナヒドロゲル形成物質としては、特殊な
ものを用いる必要はなく、汎用、廉価な、アルミ
ン酸ソーダ、アルミン酸カリ、塩化アルミニウ
ム、硝酸アルミニウム、硫酸アルミニウムなどを
用いることができる。一方、PHを調節する試薬と
しては、アルミナヒドロゲル形成物質でもよく、
アルミニウムを含有しない酸あるいはアリカリで
もよい。例えば上記アルミナヒドロゲル形成物質
の他、硫酸、硝酸、塩酸、アンモニア、カセイソ
ーダ、カセイカリ等が採用される。
系内に実質的に硫酸根を共存せしめるには、ア
ルミナヒドロゲル物質の１つとして硫酸アルミニ
ウムを用いる方法、あるいはPH調節剤として硫酸
を用いる方法は当然のことながら、アルミナヒド
ロゲル形成物質とPH調節剤の組合せにおいて、酸
性側溶液中に硫酸あるいは／および硫酸アルミニ
ウムを共存させておく方法も採りうる。添加する
アルミナヒドロゲル形成物質とPH調節剤の組合せ
としては、好ましくは、硫酸アルミニウム−アル
ミン酸ソーダ、硫酸−アルミン酸ソーダ、硫酸ア
ルミニウム−カセイソーダがある。このうちでも
特に好ましくは、硫酸アルミニウム−アルミン酸
ソーダである。なぜならこの組合せにおいては、
系内を微視的に見てもPH６〜11の範囲、すなわち
擬ベーマイト生成条件に、もつとも容易に制御し
やすい系であるからである。系内における硫酸根
の存在量は、系内に存在するアルミニウムに対す
る当量比で12〜300％、好ましくは20〜100％であ
る。
アルミナヒドロゲル形成物質の添加速度には適
当な範囲が存在する。添加速度が小さいと、擬ベ
ーマイトの迅速な成長が実現しないだけでなく、
ある程度の添加速度が存在したとき起きる微細擬
ベーマイト結晶と比較的成長した擬ベーマイト結
晶の間での競争的成長の結果の擬ベーマイト結晶
サイズの均一化成長も行なわれない。一般に微細
な結晶ほど成長しやすいという特性をもつため、
微細な結晶と比較的大きい結晶が共存する系にお
いて添加操作によつて成長をなす場合には、結晶
が成長しながら均一化へ向う。したがつてアルミ
ナヒドロゲル形成物質の添加速度は、ある程度大
きくなくてはいけない。しかし添加速度が大きす
ぎても、不利な点が存在する。即ち系内に新たに
添加されるアルミナヒドロゲル形成物質量が出発
時のアルミナヒドロゲルの量に比べて多過ぎる
と、硫酸根が存在しても成長途中のベーマイトに
吸蔵されきらずに互いに結合して新たなる微細な
擬ベーマイト結晶を発生させることになる。従つ
て速すぎるアルミナヒドロゲル形成物質の添加
は、擬ベーマイト結晶の不均一な成長しかもたら
さない。即ち、添加するアルミナヒドロゲル形成
物質の速度は、擬ベーマイト結晶の選択的な成長
を実現するのに適当な値であり、なおかつ新たな
る擬ベーマイト結晶が生成しないような範囲に選
ぶべきである。この値は、出発時のアルミナヒド
ロゲルに対して、アルミニウムのモル比で１時間
当り20〜500％（即ち、出発時のアルミナヒドロ
ゲル中のAl1モルに対し１時間当り0.2〜５モルの
割合）の中にある。
アルミナヒドロゲル形成物質の添加量は、得よ
うとするアルミナの細孔容積、表面積、嵩密度に
よつて決められる。アルミナヒドロゲル形成物質
の添加量が多くなると得られるアルミナの細孔容
積は増大、表面積は減少、嵩密度は減少する傾向
にある。出発時のアルミナヒドロゲルは10〜20Å
の直径をもつ。これにアルミナヒドロゲル物質を
添加して30〜40Å以上の直径をもつ擬ベーマイト
結晶に成長せしめるとしたら、出発時のアルミナ
ヒドロゲルの数倍以上のアルミナヒドロゲル形成
物質の添加が必要である。従つて、目的とする細
孔容積、表面積、嵩密度をもつアルミナを得るた
めに必要な添加量は、擬ベーマイト結晶の存在が
Ｘ線回折上明瞭になる量以上の量であり、かつ得
られるアルミナの細孔容積が２ml／ｇ以上、嵩密
度が0.25ｇ／ml以下になる量であるといえる。通
常そのような量は、出発時のアルミナヒドロゲル
に対してアルミナモル比で約４倍以上である。一
方、添加量の上限は、特に明瞭な制限としてはな
いが、得られるアルミナの表面積が50m2／ｇ以下
にならないように設定されなければいけない。通
常30倍以下であるのが妥当である。
アルミナヒドロゲル形成物質およびPH調節剤
は、当然のことながら水溶液として添加される
が、それらの濃度に特に制限はない。しかし、系
内の撹拌やコントロールに不利をもたらすから必
要以上に希薄にしたり、高濃度にすることは望ま
しくない。また、スラリー中の固形分濃度が高く
なりすぎないように出発時のアルミナヒドロゲル
および添加するアルミナヒドロゲル形成物質の濃
度を調節すべきである。これらの濃度を高くし過
ぎると、スラリーの撹拌は充分に行えず、加えた
アルミナヒドロゲル形成物質或はPH調節剤の部分
的な濃淡が発生し、本発明の構成要件の１つであ
る擬ベーマイト生成条件下に保持することが微視
的に見て出来なくなるので好ましくない。従つて
系内は均一な撹拌が行なわれるような濃度を選択
することが望ましいし、撹拌方法も系内がたえず
均一に保たれるような方法を選ぶべきである。例
えば、Al2O3として５重量％以下程度に保つなら
ば汎用の回転羽根によるゆるやかな撹拌状態下で
も本発明の方法を行うことができる。
本発明でいう擬ベーマイト生成条件とは、通
常、50℃以上、PH６〜11であり、添加操作を大気
圧のもとで行えばスラリー濃度は100℃以上には
ならない。
生成した擬ベーマイトを水洗、濾過、乾燥する
が、本発明の擬ベーマイトは特別な洗浄方法をと
る必要はなく、通常の水洗を数回繰り返すことに
よつて、Naなどの可溶性金属イオンおよび
SO4 2-、NO3 -などのイオンを実質的に含有しな
いようにすることができる。
このようにして得られる擬ベーマイトの特徴と
しては次の様な点が挙げられる。即ち、擬ベーマ
イト基本粒子が繊維状であり密充填構造をとりに
くい。基本粒子サイズが整つているので粒子間げ
きに微細粒子がつまつて密になることはない。擬
ベーマイトの微結晶が疎に凝集した状態で補強さ
れているので、乾燥操作を経たのちのものを比較
すると、通常の繊維状基本粒子からなる充填体よ
りも凝集状態の変化が少い。これらの特徴によつ
て、この擬ベーマイトを噴霧乾燥工程にもつてい
くことによつて非常に低嵩密度で高表面積、高細
孔容積のアルミナ粉末を得ることができる。
本発明は、このようにアルミナ粉末の基本粒子
のサイズ、形状および凝集体が補強されて形成さ
れている特徴をもつた擬ベーマイトは安定な低嵩
密度アルミナの原料になることを見いだしたこと
によつて完成された。特にこの擬ベーマイトは水
溶媒中の乾燥時に働く凝縮力に抵抗する強さをも
つため、乾燥して得られるアルミナキセロゲル、
焼成して得られるアルミナを再び水あるいは油性
溶剤によつて湿潤させた時に、乾燥前の保水性あ
るいは乾燥・焼成後の細孔容積にほぼ匹敵する保
油性を持つ。一般に有機溶剤などにより乾燥工程
における凝縮を防ぐ方法では得られるアルミナは
嵩密度は低くなるが、このような保水性、保油性
に乏しいことが多い。その点、本発明の工程で得
られるアルミナは、水の直接乾燥工程を経ている
ため、アルミナ粉末の利用に関しては非常に有利
である。
本発明においては、アルミナ粉末を得るため
に、噴霧乾燥により、乾燥と粉末化を同時に行
う。乾燥工程と粉末化工程を別々に行うことがで
きるが、別に整粒工程が必要となる。その点、噴
霧乾燥法は粒度のそろつた球状の粉体を容易に得
ることができるので有利である。また、乾燥の前
に有機溶媒で処理することによつてより低嵩密度
のアルミナ粉末を得ることができるが、処理しな
くても十分な低嵩密度のアルミナに変換されるの
で必要以上に低嵩密度にする必要はなく、特殊な
目的に応じてだけ有機溶媒で処理してもよい。
本発明によれば、洗浄された擬ベーマイトは濾
過などによつて固形分濃度を調節したのち、噴霧
乾燥処理される。乾燥温度は、水溶液の場合、
100℃〜200℃であり、通気、減圧、大気下いずれ
の条件でもよい。通常、通気下で行なわれる。噴
霧乾燥後、更に必要に応じて乾燥を100℃〜200℃
で行うことができる。焼成は、400℃〜1100℃の
温度で30分以上行う。本発明における擬ベーマイ
トは400℃〜800℃の焼成ではγ−アルミナが、
800℃〜1100℃の焼成ではδないしθ−アルミナ
が主として生成する。たとえば、BET表面積に
関しては、500℃では230m2／ｇ、900℃では189
m2／ｇ、1100℃では109m2／ｇと変化する。焼成
温度は表面積だけでなくアルミナの基本粒子の大
きさ、基本粒子間げきの大きさ、表面の性質とも
密接な関係がある。一般に焼成温度が高くなると
表面積は減少するが、アルミナの基本粒子の大き
さは増し、基本粒子間げきの目開きも大きくなる
し、表面水酸基の減少に伴い疎水性、親油性が増
してくる。したがつて目的に応じて焼成温度を決
める必要がある。
次に本発明の具体的実施例及び比較例を挙げて
更に説明を行う。
比較例 １
Al2O3濃度80ｇ／の硫酸アルミニウム水溶液
0.224と脱イオン水10をホーローびき容器に
とり、90℃に加熱した後、激しく撹拌しながら、
Al2O3濃度69ｇ／のアルミン酸ソーダ水溶液
1.55を瞬時に投入し、PH10のスラリー状白色の
液を得た。これを90℃で３時間保持した時点およ
び、６時間保持した時点でも液はPH10を示してい
た。それぞれの時点で0.3ずつサンプリング液
を採取し、過して、脱イオン水で洗浄し、Na+
およびSO4 2-イオンの大部分を除去した。得られ
たフイルターケーキを固形分濃度が約２重量％と
なるように脱イオン水に再分散し、乾燥温度150
℃、約4000／minの気流下、原液供給速度約12
c.c.／min、気液混合溶積比1250の条件にて噴霧乾
燥し、アルミナキセロゲル粉末を120℃で６時間
乾燥後、500℃で３時間焼成してγ−アルミナ粉
末を得た。この試料をR1（保持時間３時間）、R2
（同６時間）としてその性状を表１に示す。R1、
R2ともほぼ同一の性状を示し、嵩密度は0.65ｇ／
c.c.と極めて大きな値を示し、細孔容積も0.7c.c.／
ｇ以下と極めて小さい値しか示さない。
比較例 ２
Al2O3濃度40ｇ／の硝酸アルミニウム水溶液
0.10と脱イオン水10をホーローびき容器にと
り、90℃に加熱した後、激しく撹拌しながら、
Al2O3濃度69ｇ／のアルミン酸ソーダ水溶液
0.35を瞬時に投入したところ、白濁し、PH9.5
のスラリー状水酸化アルミニウム水溶液が得られ
た。これを種子水酸化アルミニウムとして、これ
にAl2O3濃度８ｇ／の硝酸アルミニウム水溶液
を0.29／hr、Al2O3濃度69ｇ／のアルミン酸
ソーダ水溶液を0.20／hrの速度にて定速注入器
を用いて異なる注入口より連続的に添加した。添
加操作を続けた６時間の間は温度90℃、PH９〜10
であつた。注入開始より３時間、６時間後の時点
で0.3ずつサンプリング液を採取し、濾過し、
脱イオン水で洗浄しケーキを比較例１と同じ条件
にて噴霧乾燥し、そのアルミナキセロゲル粉末を
120℃で６時間乾燥し、その後500℃で３時間焼成
し、アルミナ担体R3（注入開始後３時間後）、R4
（注入開始後６時間後）を得た。その性状を表−
１に示す。R3は、嵩密度が大きく、細孔容積が
小さい。R4は嵩密度は小さいが細孔容積が小さ
くかつ表面積が小さい。
実施例 １
Al2O3濃度80ｇ／の硫酸アルミニウム水溶液
0.05と脱イオン水10をホーローびき容器にと
り、90℃に加熱した後、激しく撹拌しながら、
Al2O3濃度69ｇ／のアルミン酸ソーダ水溶液
0.35を瞬時に投入したところ白濁し、PH10のス
ラリー状水酸化アルミニウム水溶液が得られた。
これを種子水酸化アルミニウムとして、これに
Al2O3濃度８ｇ／の硫酸アルミニウム水溶液を
0.29／hr、Al2O3濃度69ｇ／のアルミン酸ソ
ーダ水溶液を0.20／hrの速度にて定速注入器を
用いて異なる注入口より連続的に添加した。添加
操作を続けた６時間の間は温度は90℃、PH９〜10
であつた。注入開始より３時間後、４時間後、５
時間後、６時間後の時点で0.3ずつサンプリン
グ液を採取し、濾過し、脱イオン水２に再分散
し濾過する操作による洗浄を３回繰り返し４種の
ケーキを得た。このケーキはいずれもＸ線回折上
擬ベーマイトを示した。得られたフイルターケー
キを固形分濃度が約２重量％となるように脱イオ
ン水に再分散し、乾燥温度150℃、約4000／
minの気流下、原液供給速度約12c.c.／min、気液
混合容積比1250の条件にて噴霧乾燥し、アルミナ
キセロゲル粉末とし、この粉末を温度120℃で６
時間乾燥した。その後電気炉に入れて空気を吹き
こみながら500℃で３時間焼成した。得られたγ
−アルミナ粉末は注入開始よりの時間が３時間、
４時間、５時間、６時間のものをそれぞれＡ、
Ｂ、Ｃ、Ｄとする。その性状は、比較例のアルミ
ナR1〜R4と共に表−１に示す。Ａ、Ｂ、Ｃ、Ｄ
といくにしたがつて嵩密度は徐々に小くなつてい
く。また細孔容積はいずれも2.5c.c.／ｇ以上と大
きな値を示し、かつ表面積も150m2／ｇ以上の値
を保つている。
The present invention relates to an industrially advantageous method for producing alumina powder having a low bulk density, particularly an alumina powder having a high surface area, high pore volume, low bulk density, and high oil absorption. γ-alumina, δ or θ-alumina are dehydration transfer products of pseudoboehmite, and have a wide range of uses such as adsorbents, additives, retention agents, catalysts, catalyst supports, forming aids, and coating agents. I have it.
Many of these uses include alumina's porosity, water absorption, oil absorption, adsorption, bulk density, water retention, oil retention,
This is due to purity etc. Therefore, it is desired to bring the pore volume, surface area, and bulk density of alumina to specific preferred ranges, particularly high pore volume, high surface area, and low bulk density. Methods for producing such alumina can be roughly divided into a gas phase production method and a hydrogel production method. The gas phase production method involves oxidation of metallic aluminum and thermal decomposition reaction of aluminum chloride, but the production method is accompanied by significant difficulties and has the drawbacks of high production cost. On the other hand, the hydrogel production method is a method in which pseudo-boehmite is produced once, and porous alumina is obtained by drying and firing it. Regarding this method, a method has been proposed in which the physical properties of the obtained alumina are controlled by adjusting the degree of contraction of the gel structure during the drying and firing process. There are methods such as replacing some or most of the water in the boehmite gel with an organic solvent such as alcohol, etc., but the alumina obtained by these methods has a low pore volume, high bulk density, and , they tend to have poor water resistance and, moreover, tend to be expensive to manufacture. Special Public Service 1977-
According to Publication No. 13496, alkali aluminate and
A method has been proposed in which a special pseudo-boehmite is produced by reaction with a halohydrin such as ethylene chlorohydrin, and this is used to produce alumina having a high surface area and low bulk specific gravity. However, this method also has the disadvantage of high production costs due to the use of expensive halohydrins such as ethylene chlorohydrin. The present inventors have completed the present invention as a result of intensive research aimed at developing a method for industrially advantageously producing alumina having a high surface area, high pore volume, and low bulk density. That is, according to the present invention, an alumina hydrogel-forming substance is added to an alumina hydrogel formed under conditions of pH 6 to 11 and 50°C or higher under pseudo-boehmite-forming conditions and in the presence of sulfate groups, and crystal growth is caused. ,
A pseudo-boehmite gel that forms loose aggregates is obtained, and this pseudo-boehmite gel is washed with water, spray-dried, and fired to have a pore volume of 2 to 5 ml/
g, surface area 150-300m 2 /g and bulk density 0.10-0.25
A method for producing alumina is provided, characterized in that it produces alumina of g/ml. The method of the present invention consists of a special pseudo-boehmite formation process and an alumina formation process in which the formed gel is washed, dried, and fired. In the pseudo-boehmite formation process, an alumina hydrogel-forming substance is used as a raw material, and an alumina hydrogel, so-called seed gel in crystal growth (hereinafter referred to as starting alumina hydrogel), is formed under conditions of pH 6 to 11 and 50°C or higher. Using this alumina hydrogel as a seed, an alumina hydrogel-forming substance is further added to the seed alumina hydrogel under pseudo-boehmite forming conditions in a state in which sulfate groups substantially coexist, and finally crystal growth occurs. And pseudo-boehmite is formed which forms loose aggregates. There is no need to use a special alumina hydrogel-forming substance, and general-purpose, inexpensive materials such as sodium aluminate, potassium aluminate, aluminum chloride, aluminum nitrate, and aluminum sulfate can be used. On the other hand, as a reagent for adjusting pH, an alumina hydrogel forming substance may be used.
An acid or alkali that does not contain aluminum may be used. For example, in addition to the above-mentioned alumina hydrogel-forming substances, sulfuric acid, nitric acid, hydrochloric acid, ammonia, caustic soda, caustic potash, etc. may be used. In order to substantially coexist sulfate groups in the system, it is natural to use aluminum sulfate as one of the alumina hydrogel substances, or sulfuric acid as a PH regulator. In this combination, it is also possible to make sulfuric acid and/or aluminum sulfate coexist in the acidic solution. Preferable combinations of alumina hydrogel-forming substance and PH regulator to be added include aluminum sulfate-sodium aluminate, sulfuric acid-sodium aluminate, and aluminum sulfate-caustic soda. Among these, particularly preferred is aluminum sulfate-sodium aluminate. Because in this combination,
This is because it is a system that can be easily controlled within the PH range of 6 to 11, ie, pseudo-boehmite production conditions, even when looking at the inside of the system microscopically. The amount of sulfate radicals present in the system is 12 to 300%, preferably 20 to 100%, in terms of equivalent ratio to aluminum present in the system. A suitable range exists for the rate of addition of the alumina hydrogel forming material. The small addition rate not only does not achieve the rapid growth of pseudoboehmite;
Uniform growth of pseudo-boehmite crystal size as a result of competitive growth between fine pseudo-boehmite crystals and relatively grown pseudo-boehmite crystals, which occurs when a certain addition rate exists, also does not occur. In general, the finer the crystal, the easier it is to grow.
When growth is performed by addition operation in a system where fine crystals and relatively large crystals coexist, the crystals tend to become uniform as they grow. Therefore, the rate of addition of the alumina hydrogel-forming substance must be relatively high. However, there are also disadvantages if the addition rate is too high. In other words, if the amount of the alumina hydrogel-forming substance newly added to the system is too large compared to the amount of alumina hydrogel at the beginning, even if sulfate groups exist, they will not be occluded by the growing boehmite and will combine with each other and form new ones. This results in the generation of fine pseudo-boehmite crystals. Therefore, adding the alumina hydrogel-forming material too quickly will only result in non-uniform growth of pseudo-boehmite crystals. That is, the rate of addition of the alumina hydrogel-forming substance should be selected within a range that is appropriate for achieving selective growth of pseudo-boehmite crystals and does not generate new pseudo-boehmite crystals. This value corresponds to a molar ratio of aluminum of 20 to 500% per hour relative to the starting alumina hydrogel (i.e., a rate of 0.2 to 5 mol per hour for each mol of Al in the starting alumina hydrogel). It's inside. The amount of the alumina hydrogel-forming substance added is determined depending on the pore volume, surface area, and bulk density of the alumina to be obtained. When the amount of the alumina hydrogel-forming substance added increases, the pore volume of the resulting alumina tends to increase, the surface area decreases, and the bulk density tends to decrease. The starting alumina hydrogel is 10–20 Å
has a diameter of If an alumina hydrogel substance is added to this to grow pseudo-boehmite crystals with a diameter of 30 to 40 Å or more, it is necessary to add several times more of the alumina hydrogel-forming substance than the starting alumina hydrogel. Therefore, the amount of addition required to obtain alumina with the desired pore volume, surface area, and bulk density is an amount that is greater than the amount that makes the presence of pseudo-boehmite crystals obvious on X-ray diffraction, and that can be obtained. It can be said that the amount is such that the pore volume of alumina is 2 ml/g or more and the bulk density is 0.25 g/ml or less. Typically such amount is about 4 times or more the molar ratio of alumina to the starting alumina hydrogel. On the other hand, the upper limit of the amount added must be set so that the surface area of the alumina obtained does not become less than 50 m 2 /g, although there is no specific limit. Normally, it is appropriate that it is 30 times or less. The alumina hydrogel-forming substance and the PH regulator are naturally added as an aqueous solution, but there are no particular limitations on their concentrations. However, it is undesirable to dilute it more than necessary or make it more concentrated, as this will bring disadvantages to stirring and control within the system. Also, the concentrations of the starting alumina hydrogel and the added alumina hydrogel forming substance should be adjusted so that the solids concentration in the slurry does not become too high. If these concentrations are too high, the slurry cannot be stirred sufficiently, and the added alumina hydrogel-forming substance or PH regulator may become partially concentrated, resulting in pseudo-boehmite, which is one of the constituent elements of the present invention. This is not preferable since it becomes microscopically impossible to maintain the production conditions. Therefore, it is desirable to select a concentration that will ensure uniform stirring within the system, and a stirring method that will constantly maintain uniformity within the system. For example, the method of the present invention can be carried out even under gentle stirring using a general-purpose rotary blade, provided that Al 2 O 3 is kept at about 5% by weight or less. The conditions for producing pseudo-boehmite in the present invention are usually 50°C or higher and a pH of 6 to 11, and if the addition operation is performed under atmospheric pressure, the slurry concentration will not rise to 100°C or higher. The generated pseudo-boehmite is washed with water, filtered, and dried, but the pseudo-boehmite of the present invention does not require any special washing method, and can be washed with water several times to remove soluble metal ions such as Na and
It can be made substantially free of ions such as SO 4 2- and NO 3 - . The pseudo-boehmite obtained in this way has the following characteristics. That is, the pseudo-boehmite basic particles are fibrous and difficult to form a close-packed structure. Since the basic particle size is uniform, fine particles do not become densely packed in the spaces between particles. Since the pseudo-boehmite microcrystals are reinforced in a loosely agglomerated state, when compared after drying, the agglomerated state changes less than in a packing made of ordinary fibrous basic particles. Due to these characteristics, an alumina powder with a very low bulk density, high surface area, and high pore volume can be obtained by subjecting this pseudoboehmite to a spray drying process. The present invention is based on the discovery that pseudo-boehmite, which has the characteristics that the size, shape, and aggregates of the basic particles of alumina powder are reinforced, can be used as a stable raw material for low bulk density alumina. It was completed. In particular, this pseudo-boehmite has the strength to resist the condensation force that acts during drying in an aqueous solvent, so the alumina xerogel obtained by drying,
When the alumina obtained by firing is re-wetted with water or an oil-based solvent, it has an oil retention property that is almost comparable to the water retention property before drying or the pore volume after drying and firing. In general, a method of preventing condensation during the drying process using an organic solvent or the like results in alumina having a low bulk density, but often has poor water and oil retention properties. In this respect, since the alumina obtained by the process of the present invention has undergone a direct water drying process, it is very advantageous in terms of the use of alumina powder. In the present invention, in order to obtain alumina powder, drying and powdering are performed simultaneously by spray drying. Although the drying step and the powdering step can be performed separately, a separate sizing step is required. In this respect, the spray drying method is advantageous because it can easily produce spherical powder with uniform particle size. In addition, alumina powder with a lower bulk density can be obtained by treating it with an organic solvent before drying, but it is converted to alumina with a sufficiently low bulk density even without treatment, so the bulk density is lower than necessary. There is no need for bulk density, and treatment with organic solvents may be used only for special purposes. According to the present invention, the washed pseudoboehmite is subjected to a spray drying treatment after adjusting the solid content concentration by filtration or the like. The drying temperature for an aqueous solution is
The temperature is 100°C to 200°C, and any conditions such as ventilation, reduced pressure, or atmospheric conditions may be used. Usually done under ventilation. After spray drying, further drying at 100℃ to 200℃ if necessary.
It can be done with Firing is performed at a temperature of 400°C to 1100°C for 30 minutes or more. When the pseudo-boehmite in the present invention is fired at 400°C to 800°C, γ-alumina is
When fired at 800°C to 1100°C, δ or θ-alumina is mainly produced. For example, the BET surface area is 230 m 2 /g at 500°C and 189 m 2 /g at 900°C.
m 2 /g, which changes to 109 m 2 /g at 1100°C. The firing temperature is closely related not only to the surface area but also to the size of the basic particles of alumina, the size of the gaps between the basic particles, and the properties of the surface. Generally, as the firing temperature increases, the surface area decreases, but the size of the basic alumina particles increases, the gap between the basic particles also increases, and as the surface hydroxyl groups decrease, hydrophobicity and lipophilicity increase. Therefore, it is necessary to determine the firing temperature depending on the purpose. Next, further explanation will be given by giving specific examples and comparative examples of the present invention. Comparative Example 1 Aluminum sulfate aqueous solution with Al 2 O 3 concentration of 80 g/
0.224 and deionized water were placed in an enameled container, heated to 90℃, and stirred vigorously.
Sodium aluminate aqueous solution with Al 2 O 3 concentration 69g/
1.55 was added instantly to obtain a slurry-like white liquid with a pH of 10. The liquid had a pH of 10 when it was held at 90°C for 3 hours and also when it was held for 6 hours. 0.3 samples were taken at each time point, filtered, washed with deionized water, and washed with Na +
and most of the SO 4 2- ions were removed. The resulting filter cake was redispersed in deionized water to a solids concentration of approximately 2% by weight, and dried at a drying temperature of 150°C.
°C, under air flow of approximately 4000/min, stock solution supply rate approximately 12
Spray drying was carried out under conditions of cc/min and gas-liquid volume ratio of 1250, and the alumina xerogel powder was dried at 120°C for 6 hours and then calcined at 500°C for 3 hours to obtain γ-alumina powder. This sample was subjected to R 1 (retention time 3 hours), R 2
(6 hours) and its properties are shown in Table 1. R1 ,
It shows almost the same properties as R 2 , and the bulk density is 0.65g/
It shows an extremely large value of cc, and the pore volume is also 0.7cc/
It shows only an extremely small value of less than g. Comparative Example 2 Aluminum nitrate aqueous solution with Al 2 O 3 concentration of 40 g/
Put 0.10 and deionized water 10 in an enameled container, heat it to 90℃, and stir vigorously.
Sodium aluminate aqueous solution with Al 2 O 3 concentration 69g/
When I added 0.35 instantly, it became cloudy and the pH was 9.5.
A slurry-like aluminum hydroxide aqueous solution was obtained. This was used as a seed aluminum hydroxide, and an aluminum nitrate aqueous solution with an Al 2 O 3 concentration of 8 g/h was added at a rate of 0.29/hr, and a sodium aluminate aqueous solution with an Al 2 O 3 concentration of 69 g/h was added at a rate of 0.20/hr using a constant-rate injector. It was added continuously from different injection ports using a . During the 6 hours that the addition operation continued, the temperature was 90℃ and the pH was 9 to 10.
It was hot. 3 hours and 6 hours after the start of injection, 0.3 samples were taken and filtered.
After washing with deionized water, the cake was spray-dried under the same conditions as Comparative Example 1, and the alumina xerogel powder was
Dry at 120°C for 6 hours, then sinter at 500°C for 3 hours to form alumina carrier R 3 (3 hours after the start of injection), R 4
(6 hours after the start of injection) was obtained. Show its properties.
Shown in 1. R3 has a large bulk density and a small pore volume. R 4 has a small bulk density, but a small pore volume and a small surface area. Example 1 Aluminum sulfate aqueous solution with Al 2 O 3 concentration of 80 g/
0.05 and deionized water were placed in an enameled container, heated to 90℃, and stirred vigorously.
Sodium aluminate aqueous solution with Al 2 O 3 concentration 69g/
When 0.35 was added instantly, it became cloudy and a slurry-like aluminum hydroxide aqueous solution with pH 10 was obtained.
This is used as a seed aluminum hydroxide.
An aluminum sulfate aqueous solution with an Al 2 O 3 concentration of 8 g/
A sodium aluminate aqueous solution having an Al 2 O 3 concentration of 69 g/hr was added continuously at a rate of 0.20/hr from different injection ports using a constant rate syringe. During the 6 hours that the addition operation continued, the temperature was 90℃ and the pH was 9 to 10.
It was hot. 3 hours, 4 hours, and 5 hours after the start of injection
After 6 hours, 0.3 samples were taken, filtered, redispersed in deionized water 2, and filtered. Washing was repeated three times to obtain four types of cakes. All of these cakes showed pseudo-boehmite on X-ray diffraction. The obtained filter cake was redispersed in deionized water so that the solid content concentration was about 2% by weight, and dried at a drying temperature of 150°C and about 4000% by weight.
The alumina xerogel powder was obtained by spray drying under the conditions of an air flow of 12 min, a stock solution supply rate of about 12 c.c./min, and a gas-liquid mixing volume ratio of 1250.
Dry for an hour. After that, it was placed in an electric furnace and fired at 500℃ for 3 hours while blowing air. The obtained γ
- For alumina powder, the time from the start of injection is 3 hours,
A for 4 hours, 5 hours, and 6 hours, respectively.
Let them be B, C, and D. Its properties are shown in Table 1 together with aluminas R 1 to R 4 of comparative examples. A, B, C, D
As time goes by, the bulk density gradually decreases. In addition, the pore volumes all showed large values of 2.5 cc/g or more, and the surface areas also maintained values of 150 m 2 /g or more.
【表】
実施例 ２
Al2O3濃度40ｇ／の硝酸アルミニウム水溶液
0.10と脱イオン水10をホーローびき容器にと
り、90℃に加熱した後、激しく撹拌しながら、
Al2O3濃度69ｇ／のアルミン酸ソーダ水溶液
0.35を瞬時に投入したところ、白濁し、PH9.5
のスラリー状水酸化アルミニウム水溶液が得られ
た。これを種子水酸化アルミニウムとして、これ
に実施例１と同じ添加操作を行つて、添加開始後
３時間、６時間のγ−アルミナ粉末Ｅ、Ｆが得ら
れた。その性状を表−２に示す。Ｅは嵩密度が
0.22ｇ／c.c.と比較的大きい値であり、細孔容積が
2.53c.c.／ｇとまだ未発達の状態に近いが、Ｆは嵩
密度が0.18ｇ／c.c.となり、細孔容積も3.0c.c.／ｇ
以上となつている。[Table] Example 2 Aluminum nitrate aqueous solution with Al 2 O 3 concentration of 40 g/
Put 0.10 and deionized water 10 in an enameled container, heat it to 90℃, and stir vigorously.
Sodium aluminate aqueous solution with Al 2 O 3 concentration 69g/
When I added 0.35 instantly, it became cloudy and the pH was 9.5.
A slurry-like aluminum hydroxide aqueous solution was obtained. This was used as a seed aluminum hydroxide, and the same addition operation as in Example 1 was performed to obtain γ-alumina powders E and F for 3 hours and 6 hours after the start of addition. Its properties are shown in Table-2. E is the bulk density
The value is relatively large at 0.22g/cc, and the pore volume is
Although it is still in an undeveloped state at 2.53cc/g, the bulk density of F is 0.18g/cc and the pore volume is 3.0cc/g.
That's all.
【表】
実施例 ３
11.6wt％硫酸水溶液0.15と脱イオン水10を
ホーローびき容器にとり、80℃に加熱した後、激
しく撹拌しながら、Al2O3濃度69ｇ／のアルミ
ン酸ソーダ水溶液0.4を瞬時に投入したところ、
白濁し、PH10のスラリー状水酸化アルミニウム水
溶液が得られた。これを種子水酸化アルミニウム
として、これに11.6wt％の硫酸水溶液を0.13／
hr、Al2O3濃度69ｇ／のアルミン酸ソーダ水溶
液を0.27／hrの速度にて定速注入器を用いて異
なる注入口より連続的に添加した。添加操作をつ
づけた９時間のあいだ温度は80℃に保たれ、PHは
9.5〜10の値を示していた。注入開始より６時間
後、９時間後の時点で0.3ずつサンプリング液
を採取し、以下実施例１と同様の操作にてγ−ア
ルミナ粉末Ｇ、Ｈを得た。その性状を表−３に示
す。この方法によつてもγ−アルミナ担体Ｈの性
状に示されるように低嵩密度でかつ細孔容積が大
きくかつ表面積も大きく保たれているように製造
できることがわかる。[Table] Example 3 Place 0.15 of an 11.6 wt% sulfuric acid aqueous solution and 10 of deionized water in an enameled container, heat it to 80°C, and then instantaneously add 0.4 of a sodium aluminate aqueous solution with an Al 2 O 3 concentration of 69 g/h while stirring vigorously. When I put it into
A slurry-like aluminum hydroxide aqueous solution was obtained which was cloudy and had a pH of 10. This is used as seed aluminum hydroxide, and 11.6wt% sulfuric acid aqueous solution is added to it at 0.13%
An aqueous sodium aluminate solution having an Al 2 O 3 concentration of 69 g/hr was added continuously at a rate of 0.27/hr from different injection ports using a constant rate syringe. The temperature was maintained at 80°C during the 9 hours that the addition operation continued, and the pH was
It showed a value of 9.5 to 10. After 6 hours and 9 hours after the start of injection, 0.3 samples of the liquid were taken, and the same procedure as in Example 1 was carried out to obtain γ-alumina powders G and H. Its properties are shown in Table 3. It can be seen that even by this method, it is possible to produce a γ-alumina carrier H that has a low bulk density, a large pore volume, and a large surface area, as shown in the properties of the γ-alumina carrier H.
【表】
実施例 ４
Al2O3濃度80ｇ／の硫酸アルミニウム水溶液
0.25と脱イオン水10をホーロー製容器にと
り、70℃に加熱した後、激しく撹拌しながら、５
規定の水酸化ナトリウム水溶液を0.34加えたと
ころ、白濁し、PH10.5を示すスラリー状水酸化ア
ルミニウムが得られた。これを種子水酸化アルミ
ニウムとして、これにAl2O3濃度80ｇ／の硫酸
アルミニウム水溶液を0.25／hr、５規定の水酸
化ナトリウム水溶液を0.31／hrの速度にて定速
注入器を用いて異なる注入口より連続的に添加し
た。添加操作をつづけた３時間のあいだ温度は70
℃に保たれPHは9.5〜10.5の値を示した。注入開
始より、３時間後の時点で注入を停止し、実施例
１と同様の操作によりγ−アルミナ粉末Ｉを得
た。この性状を表−６に示す。γ−アルミナ粉末
Ｉは実施例１のγ−アルミナ粉末Ｂとほぼ類似の
性状を示している。したがつて、この試薬の組合
せによつても本発明の方法は行うことができる。[Table] Example 4 Aluminum sulfate aqueous solution with Al 2 O 3 concentration of 80 g/
0.25 and deionized water were placed in an enamel container, heated to 70℃, and heated to 50℃ while stirring vigorously.
When 0.34 of the specified aqueous sodium hydroxide solution was added, a slurry of aluminum hydroxide that became cloudy and had a pH of 10.5 was obtained. This was used as a seed aluminum hydroxide, and an aluminum sulfate aqueous solution with an Al 2 O 3 concentration of 80 g/h was added at a rate of 0.25/hr, and a 5N sodium hydroxide aqueous solution was added at a rate of 0.31/hr using a constant-rate syringe. It was added continuously from the inlet. During the 3 hours that the addition operation continued, the temperature remained at 70°C.
The pH was kept at 9.5-10.5. The injection was stopped 3 hours after the start of the injection, and γ-alumina powder I was obtained by the same operation as in Example 1. This property is shown in Table-6. γ-Alumina powder I exhibits almost similar properties to γ-Alumina powder B of Example 1. Therefore, the method of the present invention can also be carried out using this combination of reagents.
【表】
実施例 ５
実施例１においてγ−アルミナ粉末Ｂを与える
噴霧乾燥粉末を焼成温度500℃の代りに1000℃に
て３時間の焼成を行つてθ−アルミナ粉末として
Ｊを得た。その性状を表−７に示す。θ−アルミ
ナ粉末の嵩密度は小さく、細孔容積は大きい。ま
た表面積はγ−アルミナ粉末Ｂと比べて減少して
いるが150m2／ｇを上回り、大きな値をもつてい
る。[Table] Example 5 The spray-dried powder that gave γ-alumina powder B in Example 1 was fired at 1000°C for 3 hours instead of at 500°C to obtain θ-alumina powder J. Its properties are shown in Table-7. Theta-alumina powder has a small bulk density and a large pore volume. Although the surface area is reduced compared to γ-alumina powder B, it still has a large value exceeding 150 m 2 /g.
【表】
実施例 ６
Al2O3濃度80ｇ／の硝酸アルミニウム水溶液
と11.6wt％硫酸水溶液を重量比１：１に混合した
硝酸アルミニウム／硫酸混合液を調製し、この溶
液0.25と脱イオン水10をホーロー製容器にと
り、70℃に加熱した後、激しく撹拌しながら、５
規定の水酸化ナトリウム水溶液を0.22加えたと
ころ、白濁し、PH10を示すスラリー状水酸化アル
ミニウムが得られた。これを種子水酸化アルミニ
ウムとして、これに先に調製した硝酸アルミニウ
ム／硫酸混合液を0.25／hr、５規定の水酸化ナ
トリウム水溶液を約0.20／hrの速度にて定速注
入器を用いて異なる注入口より連続的に添加し
た。添加操作をつづけた３時間のあいだ温度は70
℃に保たれPHは9.5〜10.5の値を示した。注入開
始より、３時間後の時点で注入を停止し、実施例
１と同様の操作によりγ−アルミナ粉末Ｋを得
た。この性状を表−８に示す。このものは、実施
例１のγ−アルミナ粉末Ｃとほぼ類似の性状を示
している。したがつて、この試薬の組合せによつ
ても本発明の方法は行うことができる。[Table] Example 6 An aluminum nitrate/sulfuric acid mixed solution was prepared by mixing an aluminum nitrate aqueous solution with an Al 2 O 3 concentration of 80 g/1 and a 11.6 wt% sulfuric acid aqueous solution at a weight ratio of 1:1, and 0.25% of this solution and 10% of deionized water were mixed. was placed in an enamel container, heated to 70℃, and stirred vigorously for 5 minutes.
When 0.22 of the specified aqueous sodium hydroxide solution was added, a slurry of aluminum hydroxide that became cloudy and had a pH of 10 was obtained. This was used as a seed aluminum hydroxide, and the previously prepared aluminum nitrate/sulfuric acid mixture was added at a rate of 0.25/hr and the 5N sodium hydroxide aqueous solution was added at a rate of approximately 0.20/hr using a constant-rate syringe. It was added continuously from the inlet. During the 3 hours that the addition operation continued, the temperature remained at 70°C.
The pH was kept at 9.5-10.5. The injection was stopped 3 hours after the start of the injection, and γ-alumina powder K was obtained by the same operation as in Example 1. The properties are shown in Table 8. This powder exhibits properties almost similar to those of γ-alumina powder C of Example 1. Therefore, the method of the present invention can also be carried out using this combination of reagents.
【表】
実施例 ７
実施例６において硝酸アルミニウムの代りに塩
化アルミニウムを用いて塩化アルミニウム／硫酸
混合液を調製し、これを硝酸アルミニウム／硫酸
混合液の代りに用い、以下同様の操作にてγ−ア
ルミナ粉末Ｌを得た。この性状を表−８に示す。
このγ−アルミナ粉末Ｌは実施例１のγ−アルミ
ナ粉末ＢないしＣとほぼ類似の性状を示してい
る。したがつて、この試薬の組合せによつても本
発明の方法を行うことができる。[Table] Example 7 In Example 6, aluminum chloride was used instead of aluminum nitrate to prepare an aluminum chloride/sulfuric acid mixture, and this was used instead of the aluminum nitrate/sulfuric acid mixture. - Alumina powder L was obtained. The properties are shown in Table 8.
This γ-alumina powder L exhibits almost similar properties to the γ-alumina powders B to C of Example 1. Therefore, the method of the present invention can also be carried out using this combination of reagents.
Claims (1)
ルミナヒドロゲルに、アルミナヒドロゲル形成物
質を、温度50℃以上及びPH６〜11の条件下及び硫
酸根の共存下で添加し、結晶成長し、疎擬集体を
形成する擬ベーマイトゲルを得ると共に、この擬
ベーマイトゲルを水洗後、噴霧乾燥し、焼成する
ことにより、細孔容積２〜５ml／ｇ、表面積150
〜300m2／ｇ及び嵩密度0.10〜0.25ｇ／mlのアル
ミナを生成させることを特徴とするアルミナの製
造方法。 ２ アルミナヒドロゲル形成物質が硫酸アルミニ
ウム及び又はアルミン酸ソーダである特許請求の
範囲第１項の方法。 ３ 噴霧乾燥後、400〜800℃で焼成を行い、γ−
アルミナを形成させる特許請求の範囲第１項又は
第２項の方法。 ４ 噴霧乾燥後、800〜1100℃で焼成を行い、δ
又はθ−アルミナを得る特許請求の範囲第１項又
は第２項の方法。[Claims] 1. An alumina hydrogel-forming substance is added to an alumina hydrogel formed at a temperature of 50°C or higher, a pH of 6 to 11, and in the presence of a sulfate group. Then, by obtaining a pseudo-boehmite gel in which crystals grow and form loose aggregates, this pseudo-boehmite gel is washed with water, spray-dried, and fired to have a pore volume of 2 to 5 ml/g and a surface area of 150
A method for producing alumina, characterized in that it produces alumina of ~300 m 2 /g and a bulk density of 0.10 to 0.25 g/ml. 2. The method according to claim 1, wherein the alumina hydrogel forming substance is aluminum sulfate and/or sodium aluminate. 3 After spray drying, calcination is performed at 400 to 800℃ to obtain γ-
A method according to claim 1 or claim 2 for forming alumina. 4 After spray drying, calcination is performed at 800 to 1100℃, and δ
or the method of claim 1 or 2 for obtaining θ-alumina.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57177838A JPS5969424A (en) | 1982-10-08 | 1982-10-08 | Manufacture of alumina having low bulk density |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57177838A JPS5969424A (en) | 1982-10-08 | 1982-10-08 | Manufacture of alumina having low bulk density |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5969424A JPS5969424A (en) | 1984-04-19 |
| JPH0132169B2 true JPH0132169B2 (en) | 1989-06-29 |
Family
ID=16037995
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57177838A Granted JPS5969424A (en) | 1982-10-08 | 1982-10-08 | Manufacture of alumina having low bulk density |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5969424A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995015920A1 (en) * | 1993-12-09 | 1995-06-15 | Catalysts & Chemicals Industries Co., Ltd. | Process and equipment for producing alumina |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1017321A (en) * | 1996-06-27 | 1998-01-20 | Catalysts & Chem Ind Co Ltd | Small alumna sphere and its production |
| JP4021513B2 (en) * | 1997-02-21 | 2007-12-12 | 水澤化学工業株式会社 | Alumina or alumina hydrate having ultra-low bulk density, high specific surface area, and high porosity, production method and use thereof |
| JP6890311B2 (en) * | 2016-09-05 | 2021-06-18 | 国立研究開発法人日本原子力研究開発機構 | Pseudo-boehmite alumina molybdenum adsorbent and 99Mo / 99mTc generator using it |
| CN110372021A (en) * | 2019-06-13 | 2019-10-25 | 山东泰星新材料股份有限公司 | A kind of preparation method and application of electronic circuit board or electrician's fire retardant aluminium hydroxide |
| CN112875735B (en) * | 2021-02-09 | 2021-09-28 | 洛阳中超新材料股份有限公司 | Production method of high-crystallization-strength superfine aluminum hydroxide |
-
1982
- 1982-10-08 JP JP57177838A patent/JPS5969424A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995015920A1 (en) * | 1993-12-09 | 1995-06-15 | Catalysts & Chemicals Industries Co., Ltd. | Process and equipment for producing alumina |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5969424A (en) | 1984-04-19 |
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