JP2004224687A - Manufacturing method of zeolite using paper sludge ash as raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To actively and effectively use paper sludge ash which is discharged through paper recycling process but currently has no means for disposal except for landfill disposal after incineration, by inexpensively converting it into zeolite on a large scale. <P>SOLUTION: The paper sludge ash is used as a raw material for manufacturing zeolite. A reaction material is prepared, loaded into an autoclave and reacted at a high temperature under high pressure to produce zeolite. The obtained zeolite is treated with an aqueous carbonic acid solution to remove carbonate ion or calcium carbonate contained in the produced zeolite. This improves characteristics such as adsorption capacity of the zeolite to enable its more effective use. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００２３】
上記表１に示す各試料をそれぞれ水熱反応により反応させた結果、得られた生成物を回収し、洗浄し、乾燥後Ｘ線回折パターンにより分析した。その結果は、以下図１〜図１３に示すとおりＸ線回折パターンであった。
【００２４】
図１に、ｐｓ−１とｐｓ−２のＸ線回折パターンを示す。分析の結果、この配合設計と反応条件のもとでは、５員環構造に属するモルデナイトあるいは、ＺＳＭ−５型ゼオライトが生成することが明らかとなった。出発組成は、モルデナイトが生成しやすい配合設計に基づいたものであるが、モルデナイト以外にＺＳＭ−５も少し副生した。これは、モルデナイトとＺＳＭ−５がどちらも５員環からなるゼオライトであり、合成条件が似ているため、ＺＳＭ−５も生成したと考えられる。また、ＰＳ灰に含まれる炭素成分などがテンプレートとして働き、これがＺＳＭ−５をも一部生成させる原因となったものと考えられる。
この対策として、すなわち単一相の生成物を得るためには、使用するペーパースラッジ灰は、さらに炭素を除去したものを使用すること、あるいはアルカリ溶解性を向上させるため、事前にアルカリと予備的に反応させておく等の措置を講じておくことが有力な手段であると考えられる。
【００２５】
なお、本実施例は、このｐｓ−２に示す例のように、反応条件によってはその生成するゼオライトに複数のゼオライトが生成する場合も含むものであるが、このように副生物を伴う反応によっても、実用上は支障がない限りは、本発明は有用な発明をなしたことに変わりはなく、産業上利用しうる発明をなしたものであることは勿論である。すなわち、合成ゼオライトの場合、複数相のゼオライトが生成することは良くあることであり、用途等に極めて厳密な物性が要求される場合は別にして、例えば土壌改良材や、脱臭剤、乾燥剤等のようなそれほど厳密な物性が要求されない通常の用途に供する場合には、複数相のゼオライトが混入、副生したとしても実用上何ら差し支えはなく、所期のねらいとするペーパースラッジ灰を付加価値の高い物性を持ったものに転換するという目的は、これを達成することが出来たものであることは言うまでもない。
勿論、さらに純粋な単一相を希求することは当然に含まれるものであることは言うまでもない。本実施例は、その蓋然性を開示し、その先駆的意義を提供しているものである。
【００２６】
次に、ｐｓ−３とｐｓ−５に記載する配合設計と反応条件によって生成した生成物は、図２に示すとおりのＸ線回折パターンであった。同定したところ、共にアナルサイムが生成したことが確認された。ｐｓ−１、あるいはｐｓ−２と比較すると、Ａｌ成分であるＰＳ灰の配合比を多く配合したことにより、４員環と６員環が出来やすくなり、アナルサイムが主として生成した。
【００２７】
次に、ｐｓ−６とｐｓ−７に記載する配合設計と反応条件によって生成した生成物のＸ線回折パターンと比較のためＰＳ灰自体のＸ線回折パターンとを図３に示す。その結果は、これらの試料には、カンクリナイトが生成していることが明らかとなった。但し、ペーパースラッジ灰が、反応せず一部そのまま混入していることも明らかとなった。この理由は、ｐｓ−５の組成よりもＡｌ成分であるＰＳ灰を多くしたため、ＰＳ灰が溶解せずに、未反応のまま残ってしまったものと考えられる。ｐｓ−６とｐｓ−７の組成設計は、水のモル比を２倍とし、水の多寡による影響をみるものであったが、このＸ線回折パターンによる観察からは、殆ど変化は観察されず、この場合、組成設計における水の影響は観察されなかった。
【００２８】
次に、ｐｓ−９とｐｓ−１９に記載する配合設計及び反応条件によって生成した生成物のＸ線回折パターンと比較のためＰＳ灰自体のＸ線回折パターンとを図４に示す。その結果は、これらの試料では、アナルサイムが生成していることが分かった。但し、ＰＳ灰に由来すると考えられる未反応成分の混入と、ピーク強度が弱いので明確に同定することが困難であるが、モルデナイト、あるいはヒューランダイトと思われる弱いピークも一部観察された。そしてこのＸ線回折パターンからみると、ｐｓ−７と同様に、Ａｌ成分として配合したＰＳ灰が一部溶解せず未反応成分として残っていることが示された。これらの試料においては、アルカリ成分がＰＳ灰を溶解するのに必要な量に満たなかったものと考えられる。また、ｐｓ−６およびｐｓ−７よりもＳｉ成分を増やしたことによって、かえってカンクリナイトの生成領域を外れてしまう結果となり、これがアナルサイムを生成させ、カンクリナイトが生成出来なかった原因と考えられる。
【００２９】
次に、ｐｓ−１０、ｐｓ−１１、ｐｓ−１２、及びｐｓ−１３に記載する配合設計と反応条件によって生成した生成物のＸ線回折パターンと比較のためＰＳ灰自体のＸ線回折パターン及びｐｓ−５のＸ線回折パターンを図５に示す。その結果、これらの試料からはアナルサイムが生成したことが明らかとなった。その中、ｐｓ−１０の生成物の結晶化が一番進んでいることが確認された。なお、未反応のＰＳ灰の弱いピークも一部確認されたが、実用上は問題のない範囲であると考えられる。その原因としては、ｐｓ−９の場合と同様にＡｌ成分としてＰＳ灰を多く配合したため、アルカリ成分がＰＳ灰を溶解するのに充分でなかったためと考えられる。なお、ｐｓ−１〜９とｐｓ−１９に見られた、モルデナイト、あるいはＺＳＭ−５、カンクリナイトのピークは認められなかった。Ａｌ成分とするＰＳ灰が増すことで相対的にＳｉ成分が減少し、モルデナイトなどの成分が抑えられたことが原因であると考えられる。
【００３０】
次に、ｐｓ−１６とｐｓ−１８に記載する配合設計と反応条件によって生成した生成物のＸ線回折パターンと比較のためこれら試料における反応時間よりも短く設定したｐｓ−１のＸ線回折パターンとを図６に示す。すなわち、これらの試料は、ｐｓ−１の組成は同じであるが、合成時間だけ２倍の９６時間と長くして合成を行ったものである。合成時間を長くすることで、その影響を調査するものであるが、すなわちモルデナイトあるいはＺＳＭ−５が単相で生成すると考えたが、わずかに強度比が変化しただけでさほど有意な差は見られなかった。ＰＳ灰からのゼオライト合成では、ＰＳ灰の溶解が必須の条件であるが、本例の比較実験の場合では、反応時間を単に延長するだけでは充分な溶解性の向上は望むことは出来なかった。
【００３１】
次に、ｐｓ−１７とｐｓ−２２に記載する配合設計と反応条件によって生成した生成物のＸ線回折パターンを図７に示す。ｐｓ−１７の試料例においては、アナルサイムが生成した。このｐｓ−１７の配合設計は、ｐｓ−９の反応混合物モル比組成は同じに設定し、合成時間を２倍に設定したものであるが、この場合は、反応時間の延長は優位に作用し、２倍に延長したことにより結晶の発達したアナルサイムを得ることが出来たものである。
これに対して、ｐｓ−２２は、アナルサイム以外にカンクリナイトが副生成物として生成していることが明らかとなった。このｐｓ−２２の配合設計では、ｐｓ−１９の組成よりもＮａ比を多くしたため、ＰＳ灰の溶解性が向上し、アナルサイム以外にも別の結晶核が成長し、これによってカンクリナイトも生成したものと考えられる。
【００３２】
次に、ｐｓ−２１とｐｓ−２３に記載する高アルカリ含有量による配合設計と反応条件によって生成した生成物のＸ線回折パターンを図８に示す。その結果、両試料とも、アナルサイムが生成していることが明らかとなった。アルカリ含有量を２倍に設定した高アルカリ含有量に配合したｐｓ−２３の方が、これよりもアルカリ含有量を低く設定したｐｓ−２１よりもアナルサイム以外のものを若干ではあるが、副生していた。ｐｓ−２１の組成は、ｐｓ−１の組成のＮａ比を２倍にして合成を行ったため、ＰＳ灰の溶解が促進し、反応に有効に関与するＡｌ成分が増加することで６員環が出来やすくなり、アナルサイムが生成したと考えられる。そして、ｐｓ−２３では、アルカリ成分を増加させることでアナルサイム以外にも骨格形成する要因が増え、これがアナルサイム以外のものをも若干副生するに至ったものと考えられる。
【００３３】
次に、高アルカリ含有量に設定したｐｓ−２４、ｐｓ−２８及びｐｓ−２９に示す配合設計及び反応条件による生成物のＸ線回折パターンを図９に示す。その結果、ｐｓ−２４は、主成分がカンクリナイトでこれにアナルサイムが副生成物として生成していることが明らかとなった。この試料は、ｐｓ−２２の組成よりもさらにＮａ比を２倍に多くしたことにより、アナルサイムとして成長したゼオライトは再結晶し、カンクリナイトになったと考えられる。ｐｓ−２８とｐｓ−２９は、カンクリナイトが生成した。ｐｓ−２４よりもＮａ比を多くした結果、ＰＳ灰の溶解性が増し、より結晶性の良いカンクリナイトが生成したと考えられる。
【００３４】
次に、ｐｓ−２６とｐｓ−２７に示す配合設計及び反応条件による生成物のＸ線回折パターンを図１０に示す。それぞれは、配合組成は同じに設定し、ｐｓ−２７の方を、反応温度を１０℃高く設定した。その結果は、両者の間には基本的な差は認められず、アナルサイムが生成した。なお、この両者の出発組成は、ｐｓ−２１と同じであるが、何れの場合も反成終了後に、ゲル状の部分と硬く固まった部分とが生成した。ｐｓ−２１は、これらゲル部分と固体部分とを一緒にして、ろ過し、洗浄し、乾燥し、Ｘ線回折測定を行ったものである。これに対して、ｐｓ−２６とｐｓ−２７は、吸引ろ過により、ゲル状の部分と非ゲル状固体部分とに分けて別々に測定を行った。Ｘ線回折パターンから、ゲル状の部分の方が固い部分よりピークが高角にずれていることが明らかとなった。これは、Ｓｉ部分がゲル状の部分に多いため、格子定数が小さくなったことによるものと考えられる（表２参照）。原因としてゼオライトの結晶化が行われる時は、温度が高いところ（容器の外側）から結晶化が始まり、最後に容器の中心が結晶化されていく。ゲル状の部分は、Ｓｉ成分として加えたコロイダルシリカとわずかに溶解したＰＳ灰によって結晶化したためＳｉ成分を多く取り込んだアナルサイムが生成したと考えられる。その後、時間とともにＰＳ灰が溶解することでＡｌ成分が増加し、固体部分が形成されたものと推定される。
【００３５】
【表２】

【００３６】
参考例１；
次に、ＰＳ灰をアルカリ処理したときに得られる廃液（富士工業技術センター提供）を母液として、フォージャサイトを種結晶としてゼオライト合成を試みた。
該廃液２０ｇ、該種結晶を０．２ｇを各秤量し、これらを一緒にしてオートクレーブに挿入し、これを表３に記載する条件で反応させた。
【００３７】
【表３】

【００３８】
その結果は、図１１に示すとおりのＸ線回折パターンが得られた。また、ｐｓ−１４とｐｓ−１５の格子定数を表３−２に示す。種結晶としてフォージャサイト（Ｆ−９）を用いることにより、得られた生成物は、フォージャサイトが生成した。その格子定数（表４）を比較すると、２４時間反応して結晶化したｐｓ−１４_−２４とｐｓ−１５_−２４では、もとのフォージャサイトのそれよりも大きくなり、対して４８時間結晶化した試料では、逆に小さくなった。このことは結晶化の初期から中期にかけてＡｌ成分が多く取り込まれ、母液中のＡｌ成分の減少とともにＳｉ成分の取り込み量が増え、格子定数に変化をもたらしたと考えられる。しかし、格子定数の差がわずかなことと、母液中に含まれる、ＡｌおよびＳｉ成分の量がｍｇ／ｌと少ないため、このアルカリ廃液を用いることの意義、有用性を見出すことはできなかった。
【００３９】
【表４】

【００４０】
参考例２；
次に、ペーパースラッジ灰は、アルカリに溶解しにくいため、これをフッ酸で処理し、出発原料とすることを試みた。すなわち、フッ酸を２０ｍｌ、３０ｍｌ加え数分間撹拌処理した後、アンモニア水で中和し（前者は試料ｐｓ−０１、後者は試料ｐｓ−０２で示した）、これを試料として反応混合物を調製し、ゼオライト合成を行った。その反応条件は、前記表１中、ｐｓ−４_−１、ｐｓ−４_−２で示したものである。
その結果は、図１２に示すとおりのＸ線回折パターンが得られた。すなわち、ｐｓ−０１とｐｓ−０２は、フッ酸処理を行ったため、該灰中に含まれているＳｉ成分がフッ酸と反応し、その後中和によってアンモニアと反応し、ヘキサフルオロ珪酸アンモニウムが生成した。ヘキサフルオロ珪酸アンモニウムは、ケイ素にフッ素が６配位しているため、ゼオライト骨格に必要なケイ素の４配位状態への反応性が阻害され、そのためｐｓ−４_−１、ｐｓ−４_−２は、アモルファス状のものになったと考えられ、何れにしてもペーパースラッジ灰のアルカリ溶解性を高めたものをゼオライトの原料とするにおいては、そこに一定の選択性があり、何れの手段でも有効であるとは限らないことから、事前に実験によって確認しておくことは必要であり、より好ましいことである。
【００４１】
以上の結果から、ペーパースラッジ灰を特に事前に処理することなく、ゼオライトの合成原料として使用し、オートクレーブにて水熱合成することにより合成ゼオライトを得ることは充分可能であることが確認された。この方法は、その使用する原料が廃棄されていたものに基づいたものであること、工業的規模で操業可能なプロセスに基づいてなるものであること、等からその意義は、極めて大きい。すなわち、古紙に関連する製紙工業の立地している自治体を始めとして関係団体に対しては、本発明は、元来廃棄物として処分に窮していたものを、付加価値を高めるものであるから、いうなれば新しい産業を創設し、地域に活性化をもたらす機会を提供する意義を有し、これは、極めて有力な地域振興に直結し、地域経済に対して大きなインパクトと諸点にわたり経済的、技術的波及効果をもたらすものと期待される。
本発明は、ぺーパースラッジ灰を使用した出発反応混合物の配合設計は、以上の実験に基づく知見から、大凡の目安として、モルデナイト、あるいはＺＳＭ−５をねらいとする場合、以上の実験等からＳｉＯ_２／Ａｌ_２Ｏ_３モル比を２０、Ｎａ_２Ｏ／Ａｌ_２Ｏ_３モル比を３ぐらいに設定することが好ましい。
アナルサイムをねらいとする場合、ＳｉＯ_２／Ａｌ_２Ｏ_３比＝２．３〜２０、Ｎａ_２Ｏ／Ａｌ_２Ｏ_３比＝０．４〜１２が好ましく、特に好ましくは、ＳｉＯ_２／Ａｌ_２Ｏ_３比＝２０、Ｎａ_２Ｏ／Ａｌ_２Ｏ_３比＝６〜１２の範囲が好ましい。
単相のカンクリナイトをねらいとする場合、ＳｉＯ_２／Ａｌ_２Ｏ_３比＝６．７、Ｎａ_２Ｏ／Ａｌ_２Ｏ_３比＝６〜８が好ましい範囲である。以上その具体的実施条件も、ほぼ特定され、これによってねらいとするゼオライトを反復再現性を以て製造することができるという極めて完成度の高いゼオライト製造技術を提供しているといえる。
【００４２】
次に、前示実施例の結果、結晶の発達に顕著な作用効果が認められた、ｐｓ−２９についてその熱的あるいは化学的安定性について考察するため、以下に記載する種々の処理を行い、その結晶構造の影響を調査するため再度Ｘ線回折パターンにより調査を試みた。その結果、熱処理した試料ｐｓ−２９−２とイオン交換水で処理したｐｓ−２９−３では、結晶構造の破壊は認められなかった。
合成後のカンクリナイトについては、結晶の状態は良好であったが、吸着能等において難のある場合があることが分かったのでこれを解決するため以下さらに研究を進めた。
【００４３】
その原因について、鋭意研究した結果、これはゼオライトの生成プロセスにおいて、炭酸イオンがテンプレートとなり、これがカルシウムイオンと結びついて細孔内に保持され、吸着能を低下させているものであることが分かってきた。そのため、合成ゼオライトに対してその機能を向上させるため、いくつかの基本的ないしは典型的な処理をし、ゼオライトの機能向上につながるかどうか、また、ゼオライトの構造を維持できるかどうか等についてその影響を調査した。
０．１規定の塩酸で処理し、Ｃａ成分を除去しようとしたｐｓ−２９−４と、ｐｓ−２９−２をアンモニウム交換し、熱処理を行ったｐｓ−２９−５は、共に非晶質化した。ＴＭＡＣｌを用いてＮａ成分をアンモニウムと交換し、次いで焼成したｐｓ−２９−６は、その細孔構造は壊れなかった。以上のことから、本発明によるゼオライト（カンクリナイト）は、酸性雰囲気にさらされると骨格破壊が生じることが分かった。その結果は、図１３に示すＸ線回折パターンのとおりである。
【００４４】
また、ｐｓ−１（モルデナイト）とｐｓ−９（アナルサイム）、ｐｓ−２９−１（カンクリナイト）、ｐｓ−２９−２（カンクリナイト）及びｐｓ−２９−６（カンクリナイト）、ＰＳ灰の試料について、窒素の吸着特性について調査した。 その結果、図１４に示す７７Ｋにおける吸着等温線が得られた。また、ｐｓ−１とｐｓ−９、ｐｓ−２９−１、ｐｓ−２９−２、ｐｓ−２９−３の吸着量から作成したＤＲプロットを図１５に、ＢＥＴプロットを図１６に示す。また、飽和吸着量、比表面積、含水率を表５に、モルデナイトの飽和吸着量を表６に示す。
ｐｓ−１の飽和吸着量は、市販のモルデナイトの飽和吸着量の約３分の１であった。これは、ＰＳ−１の結晶性が悪いことと、未反応のＰＳ灰が残留していることによるものと考えられる。
【００４５】
ｐｓ−９は、主に未反応のＰＳ灰とアナルサイム及びモルデナイトあるいはヒューランダイトと思われる副生成物の混合物である。アナルサイムは、Ｎ_２ 分子径よりも細孔が小さいため、窒素を吸着できない。しかし、吸着初期の吸着量の立ち上がりが観測され、マイクロ孔が存在することを示唆している。Ｘ線回折パターンからもヒューランダイトか、モルデナイトと考えられるピークが現れているため、これらの副生成物に吸着したと考えられる。
ｐｓ−２９−１は、カンクリナイトであるため吸着測定を行ったが、ｐｓ−９よりも吸着性能はよくなかった。カンクリナイトは、５．９Åの細孔を持っているが、細孔内にＣａＣＯ_３ が残留するため、実用的な吸着量を示さなかったとかんがえられる。また、ＣａＣＯ_３ をイオン交換で取り除くことは出来ないため、細孔内にＮ_２ が吸着することが出来ない。
【００４６】
ｐｓ−２９−２は、ｐｓ−２９−１をより洗浄し、吸着測定を行ったが、細孔内のＣａＣＯ_３ はさして取り除くことが出来ず、そのため吸着性能の向上もさほどの向上は認められなかった。しかし、ｐｓ−２９−１よりは微量ではあるがＣａが抜けたため、細孔容積自体は、多くなった。ｐｓ−２９−６は、アンモニウム交換後、焼成を行った試料である。吸着測定を行った結果、ｐｓ−２９−２とほぼ同じ値を示した。これによりアンモニウム交換を行っても、細孔内のＣａＣＯ_３は取りのぞくことは出来ないため吸着しなかったと考えられる。
【００４７】
【表５】

【００４８】
【表６】

【００４９】
図１７に全ての試料について総括し、要約してまとめた出発組成と生成物の関係を示す。
図１７を見ると、出発組成全体にアナルサイムが生成していた。高ＳｉＯ_２／Ａｌ_２Ｏ_３かつ低Ｎａ_２Ｏ／Ａｌ_２Ｏ_３のところでは、奇数員環が出来やすいため、モルデナイトやＺＳＭ−５の５員環を持つゼオライトが出来た。
逆に低ＳｉＯ_２／Ａｌ_２Ｏ_３かつ高Ｎａ_２Ｏ／Ａｌ_２Ｏ_３のところでは偶数員環が出来やすいため、４員環、６員環を持つゼオライトすなわちカンクリナイトが出来たと思われる。Ｎａ成分が低いところでは、ＰＳ灰が溶けないため結晶性の良いゼオライトは生成せず、Ｎａ成分が高いところではＰＳ灰は溶けやすく４員環や６員環が出来やすくなると思われる。
窒素吸着測定の結果から、モルデナイトとＺＳＭ−５の混合物が、比表面積と細孔容積が共に実用に足る値を示した。また、カンクリナイトは、期待される吸着量が示さなかったが、単相のゼオライトが生成していることから、細孔内に残留するＣａＣＯ_３を取り除くことが出来れば、さらに実用性が向上し、産業の発展に大いに寄与するものと考え、その性能の向上等につき、さらに研究を進めた。
その結果、ＣａＣＯ_３を選択的に分離、除去することに成功し、吸着特性や、イオン交換能を一般的に知られたゼオライト本来の性質が発現することを確認し、明らかにした。
【００５０】
ここに、炭酸カルシウムがゼオライト中に残存するモデル及び残存する理由は、以下の通りであると考えられる。
図１８は、合成直後のカンクリナイトの基本骨格を示している。カンクリナイトは、直径５．９Åの一次元細孔を有しているが、炭酸イオンをテンプレートとして結晶が成長し、形成されるべき細孔位置にこの炭酸イオンがカルシウムと結びついて残存し、このため有効比表面積や吸着特性等の諸性質に大きな影響を与えるものと考えられる。この一次元細孔には、さらにその細孔壁には図示されていないくぼみが存在し、そのくぼみにカルシウムイオン（Ｃａ^２＋）が存在し、前記テンプレートとして入り込んだ炭酸イオンと電荷バランスを保ち、これによってゼオライトの重要な特徴の一つである細孔内が埋め尽くされ、本来の吸着機能をはじめとする諸特性をして、発現が抑制されたゼオライトが生成する結果となったものと考えられる。
【００５１】
以上が、炭酸カルシウムがゼオライト細孔内を埋め尽くしている原因であると考えられる。特に、本発明による合成ゼオライトの中でも、一番結晶の発達が顕著だったカンクリナイトにおいて典型的であった。その構造中の細孔には、前示した理由により、炭酸イオン、カルシウムイオンが結晶生成プロセス中にテンプレートとして作用し、そのまま細孔に閉じこめられて残存した結果、生成したものと考えられる。これが結晶の発達が際だっているにもかかわらず、諸特性が期待されたほどには発現しなかった理由と考えられる。本発明者は、上記したようにこの現象についてもさらに鋭意研究した結果、炭酸カルシウムを残存したゼオライト、特にカンクリナイトから、その構造を破壊することなく炭酸カルシウムを選択的に分離、除去する手段を開発し、この手段を適用、処理することによって、ゼオライト本来の諸特性が回復し、発現することについても見いだしたものである。以下に記載する一連の実験は、上記解決手段、すなわち、本発明（９）、（１０）に対応する解決手段を具体的に開示し、この解決手段の有効性を明らかにしているものである。
【００５２】
〔実験１〕； 図１９（ａ）は、前記実施例でペーパースラッジ灰を原料として合成された（図１８）に示すカンクリナイトから、その骨格構造を破壊することなく炭酸イオンを除去したモデルを示すものである。炭酸カルシウムを除去するため本実験ではカンクリナイトをアルカリ液にて洗浄処理した。準備したアルカリ液は、３Ｎ、６Ｎ、９Ｎ、１２Ｎ（Ｎは、規定濃度を表す）の水酸化ナトリウム水溶液を調製し、３０ｍｌテフロン容器に２５ｍｌ入れ、そこに合成したカンクリナイト試料１ｇを加え密閉した。テフロン容器を３８３Ｋの空気恒温槽に入れ、１２時間熱処理を行った後、１時間室温で放冷した。処理後の試料を約１リットルのイオン交換水で洗浄し、乾燥させた後、Ｘ線回折測定により構造確認した。図１９（ｂ）は、アルカリ液にて処理後の試料のＸ線回折パターンを示すものである。なお、参考のために、処理前のカンクリナイト試料と合成原料のＰＳ灰自体のＸ線回折パターンをも併せて図示した。その結果、３Ｎ、６Ｎで処理したものは、処理前の試料と同じ回折パターンを示し、処理による変化はほとんど認められず、これらの濃度では炭酸イオン除去ができないことがわかった。さらに濃度を高めてなる９および１２Ｎの処理では、処理前の試料と比較してＸ線回折パターンに変化が見られた。これらの回折パターンから構造を確認するため、合成原料であるＰＳ灰の回折パターンとの比較を行った。その結果、まったく同じパターンではないものの、アルカリ処理することによって、原料のＰＳ灰に戻るという結果となった。ゼオライトに限らず、結晶化現象は、反応混合物と生成物の間の可逆反応であり、平衡状態にある。今回の処理条件は、結晶化の逆反応を起こす条件となり、原料のＰＳ灰が生成したものと考えられる。
以上から、アルカリ液による洗浄処理は、炭酸イオンと水酸化物イオンのイオン交換によって、炭酸イオンを取り除くことを期待した処理であるが、結果として結晶化の逆反応が起こり、炭酸イオン（炭酸カルシウム塩）除去には適さないことが明らかとなった。
【００５３】
〔実験２〕； 実験１で示したアルカリ液による洗浄処理では、炭酸イオン除去できないことが判明したので、炭酸ガスを水に溶解した炭酸水によって洗浄処理を行った。炭酸カルシウムは、水には溶解しないが、過剰の二酸化炭素を含む水（炭酸水）には、炭酸水素イオンとなって溶解することが知られている。そこで、二酸化炭素をバブリングしながら試料を攪拌し、炭酸イオン除去を試みた。
処理条件は、１００ｍｌの水に試料１ｇを分散させ、スターラーで攪拌しながら１秒に１泡の速度で二酸化炭素をバブリングした。バブリングする時間を６〜４８時間と変化させ、処理後に約１リットルのイオン交換水で洗浄し、乾燥させた後にＸ線回折測定により構造確認を行った。
図２０（ａ）は、これらの処理態様を示す実施態様概念図を示し、同（ｂ）は処理後の試料ゼオライト（カンクリナイト）のＸ線回折パターンを示している。
Ｘ線パターンからは、７．５°付近および３０°付近の２本のピーク（図中の縦線）が処理時間とともに顕著な変化を示した。しかし、それ以外のピークにはほとんど変化がなく、骨格構造は基本的に保持されていることがわかった。Ｘ線回折測定では、規則的に配列した原子をつなぐ面に由来するピークが現れる。７．５°付近のピークは、（１００）の回折ピークであり、炭酸イオンに由来するピークを示す。炭酸水洗浄の処理時間の増加とともにこの炭酸イオンに由来する（１００）ピークが消失しており、処理時間とともに経時的に炭酸イオンが除去されていることを示している。この実験では、１２時間後には消失している。また、３０°付近の２本のピークは、低角側が（３１０）と（１３０）の合成ピーク（構造的に等価）を、高角側が（３０１）のピークを示している。特に、低角側のピークの位置には、カルシウムイオンが存在している。これらのピークは、処理時間とともに１本となっている。特に（３１０）と（１３０）のピークが消失し、（３０１）のピークのみとなっていることから、炭酸イオンと電荷補償しているカルシウムイオンが除去されたことを示している。この実験から、合成ゼオライトの構造を破壊することなく吸蔵、残存している炭酸イオン、炭酸カルシウムを除去するのには、炭酸水洗浄が極めて適した方法であることが明らかとなった。
【００５４】
〔実験３〕； 本実験は、炭酸水洗浄処理によって、ゼオライトの特性がどう変化し、影響されるか、本発明ではどう改善されるかを観察し、明らかにするためのものである。本実験においては、そのための観察指標としてゼオライトの吸着特性を評価する際に使われる窒素ガスの吸着等温線調査を採用した。
この実験の結果は、図２１に示す。その結果、合成カンクリナイトでは、細孔内に炭酸イオンが存在するため、窒素がほとんど吸着していないことが明らかにされた。しかし、炭酸水洗浄後には、ミクロ細孔に特有の低圧部での急激な吸着量の増加が認められ、さらに細孔内に窒素が吸着している等温線となった。いずれの吸着等温線も相対圧（Ｐ／Ｐ_０）が０．８を超えると吸着量が増加しているが、これは粒子と粒子の隙間への吸着を示しており、カンクリナイトに由来する吸着ではない。
炭酸水洗浄後のカンクリナイトの比表面積の値は、１２４ｍ^２／ｇであった。吸着剤として十分な比表面積を有することがわかった。また、細孔内に窒素が完全に充填している領域（図中の丸で囲んだ領域）でのＤＲ−プロットから細孔容積を求めたところ、その値は０．１１３ｍｌ／ｇであった。カンクリナイトは、５．９Ａの一次元細孔を有するため、これを完全な筒と仮定して１ｇ当たりの容積を見積もったところ０．０９９ｍｌ／ｇとなった。これらの結果、両者を比較するとほぼ近似した値を示し、カンクリナイト構造が保持され、かつ炭酸イオンが除去されていることが明らかとなった。また、実測値の方がわずかに大きな値となっているが、これは本来カルシウムイオンが存在している細孔壁のくぼみにも窒素が吸着していることを示していることによるものであると思料される。
【００５５】
〔実験４〕； この実験では、炭酸水洗浄によって、ゼオライトの特性の一つであるイオン交換能がどう変化し、影響されるか、すなわち、本発明では炭酸カルシウムが除去されたことによって、イオン交換能がどう改善されるかを明らかにしようとするものである。
先ず、５０ｍｌ三角フラスコを用意し、このフラスコに１７ｍｍｏｌ／ｄｍ^３硝酸鉛水溶液を２０ｍｌずつ分取し、炭酸カルシウム除去後の試料１．０ｇ加えた。６時間毎４８時間振盪させ、その後、濾過し、固相と液相に分けた。
液相を５ｍｌ分取し、水約１５０ｍｌをコニカルビーカーに入れ、数滴のブロモチモールブルー指示薬を添加し、溶液が黄色から青色に変わるまでアンモニア水（１＋１）をパスツールピペットで添加した。酢酸ナトリウム−酢酸緩衝液４ｍｌを加え、キシレノールオレンジ指示薬約５滴を加えた。
５ｍｍｏｌ／ｄｍ^３ＥＤＴＡ滴定により鉛の濃度を求めた。濃度の算出は、あらかじめ準備しておいた１７ｍｍｏｌ／ｄｍ^３硝酸鉛水溶液と、この溶液を２０％、４０％、６０％、８０％に希釈した溶液を用いて検量線を作成し、それより求めた。固相は５００ｍｌ程度のイオン交換水で洗浄後、乾燥させＸ線回折測定およびＥＤＳ組成分析を行なった。
その結果、鉛イオン交換における溶液濃度の経時変化を図２２に示す。イオン交換を１２時間までは、溶液濃度が減少したが、その後濃度に変化は見られなくなった。初期濃度と１２時間以上の濃度一定となった時の濃度の差（ＤＣ）は、カンクリナイトの有するイオン交換性カチオン（Ｎａ＋）の１００％が鉛イオンに置換されたときの濃度変化量に相当している。通常、ゼオライトの持つカチオン量に対して大過剰に他の交換可能なイオンが溶液中に存在しても１００％のイオン交換は起こらない。しかし、炭酸イオン除去したカンクリナイトは、１００％の交換が起こっていることから、鉛イオンに対して選択的なイオン交換能を有することが明らかとなった。
炭酸イオンを除去していないカンクリナイト（合成カンクリナイト）については、細孔内に炭酸イオンが存在することで、イオンの通る通路が塞がれており、イオン交換は有意な値を示さず、ゼオライトのイオン交換性能はほとんど発揮されなかった。
【００５６】
以上の結果、炭酸ガスを過剰に含んだいわゆる炭酸水が、炭酸イオン、炭酸カルシウムを細孔内に含んでなる合成ゼオライトに対し、その機能を向上せしめるには極めて有効な手段であることが明らかになった。これにより、本発明のｐｓ灰を使用するゼオライトの製造方法をして、一層実用的レベルにまで引き上げることが可能となり、産業上極めて有意義な手段を提供し、産業の発展に大いに寄与することが期待される。
【００５７】
【発明の効果】
これまで主として廃棄処分に付されていたペーパースラッジ灰を使用して、これをオートクレーブにより高温高圧条件で処理することにより、付加価値の高いゼオライトを生成することができるようになったことは、それ自体極めて大きな意義を有するものである。本発明により、組成を予め知見しておくことによるだけで、添加するコロイダルシリカの量を調節でき、ペーパースラッジ灰のロットに依存せず高純度かつ均一な組成のゼオライトを得ることができ、原料の管理と調節は従来の多様な廃棄物系に依存する合成方法に比し、極めて簡単で、しかも大量生産に適した手段を提供したものであるので、この点でも極めて意義の認めれる発明を提供したものと思料される。特に、取り分け、カンクリナイトは５Å以上の細孔を有するカンクリナイトを単相で得ることができる態様を含んでいる点も、これにより高付加価値材料を提供することから評価に値するものと言える。加えて、ペーパースラッジ灰以外の、合成時に添加するアルカリおよびコロイダルシリカについても１ｋｇ当たり数百円と安価であり、しかも合成にかかる熱エネルギーもペーパースラッジを焼成する際に発生する熱源を利用すれば、簡単な設備投資でペーパースラッジ灰をリサイクルすることができ、それによる効果も含めると、従来法に比して極めて優位なゼオライト製造手段を提供した意義は極めて大きい。また、ゼオライト結晶の生成するプロセス中に入り込んでくる炭酸カルシウムについても、炭酸水にて接触処理するという、簡単な操作によって、容易に除去する手段を提供することができたことは、再現性のあるゼオライトの合成手段提供と相俟って、大きな意義を有し、産業の発展に資するところ極めて大であると思料される。
【図面の簡単な説明】
【図１】実施例の試料ｐｓ−１、ｐｓ−２により生成したゼオライトのＸ線パターンを示す図。
【図２】実施例の試料ｐｓ−３、ｐｓ−５により生成したゼオライトのＸ線パターンを示す図。
【図３】実施例の試料ｐｓ−６、ｐｓ−７により生成したゼオライトのＸ線パターン及びＰＳ灰自体のＸ線パターンを示す図。
【図４】実施例の試料ｐｓ−９、ｐｓ−１９により生成したゼオライトのＸ線パターン及びＰＳ灰自体のＸ線パターンを示す図。
【図５】実施例の試料ｐｓ−１０、ｐｓ−１１、ｐｓ−１２、及びｐｓ−１３により生成したゼオライトのＸ線パターン及びＰＳ灰自体のＸ線パターンを示す図。
【図６】実施例の試料ｐｓ−１６、ｐｓ−１８により生成したゼオライトのＸ線パターン及び比較のためｐｓ−１のＸ線パターンを示す図。
【図７】実施例の試料ｐｓ−１７、ｐｓ−２２により生成したゼオライトのＸ線パターンを示す図。
【図８】実施例の試料ｐｓ−２１、ｐｓ−２３により生成したゼオライトのＸ線パターンを示す図。
【図９】実施例の試料ｐｓ−２４、ｐｓ−２８及びｐｓ−２９により生成したゼオライトのＸ線パターンを示す図。
【図１０】実施例の試料ｐｓ−２６、ｐｓ−２７により生成したゼオライトのＸ線パターンを示す図。
【図１１】参考例１に記載するＰＳ灰をアルカリ処理した廃液より出発したｐｓ−１４_−２４、ｐｓ−１４_−４８、ｐｓ−１５_−２４、ｐｓ−１５_−４８により生成したゼオライトのＸ線パターンと種結晶として使用したフォージャサイト（Ｆ−９）のＸ線パターンとを示す図。
【図１２】参考例２に示すフッ酸処理したものに基づいて合成した生成物のＸ線回折パターンと、フッ酸処理後中和した生成物のＸ線回折パターンとを示す図。
【図１３】ｐｓ−２９に示す生成物について各種処理を施し、その影響について調査した後のＸ線回折パターンを示した図である。
【図１４】ｐｓ−１、ｐｓ−９、ｐｓ−２９−１及びｐｓ−２９−２の吸着等温線を示した図。
【図１５】ｐｓ−１、ｐｓ−９、ｐｓ−２９−１及びｐｓ−２９−２のＤＲプロットを示す図。
【図１６】ｐｓ−１、ｐｓ−９、ｐｓ−２９−１及びｐｓ−２９−２のＢＥＴプロットを示す図。
【図１７】出発組成と生成物の相関関係を要約して示す図。
【図１８】ペーパースラッジ灰を原料として得られ且つ細孔中に炭酸イオンを有してなる合成ゼオライト（カンクリナイト）の結晶構造モデルを示す図。
【図１９】（ａ）炭酸イオン除去処理後の合成ゼオライト（カンクリナイト）の結晶モデルと、（ｂ）アルカリ液洗浄処理による影響を示すゼオライトのＸＲＤパターン。
【図２０】（ａ）炭酸水処理を表す実施態様の概念図と、（ｂ）炭酸水処理による影響を表す合成ゼオライト（カンクリナイト）のＸＲＤパターン。
【図２１】（ａ）炭酸水処理による影響を表す合成ゼオライト（カンクリナイト）の窒素吸着値と、ゼオライトの細孔容積（計算値と実験値）を示す図。
【図２２】炭酸水処理による影響を示す合成ゼオライト（カンクリナイト）の鉛イオン交換試験結果を示す図。[0001]
[Industrial applications]
The present invention relates to a method for producing zeolite using paper sludge ash as a raw material, and particularly to a method for producing analcyme, mordenite, ZSM-5, and cancrinite. More specifically, as a raw material, paper sludge ash, which is discharged in large quantities at the time of recovery of used paper and production of recycled paper, and which is in short supply, is added with alkali, water, and, if necessary, a silica component, and the reaction mixture is added. The present invention relates to a method for preparing the above zeolite very efficiently by charging it into an autoclave, treating it at a high temperature and a high pressure of 100 ° C. or more at atmospheric pressure or higher, and reacting it. Also, the present invention relates to a zeolite obtained by the production method described above and a multifunctional material including a deodorant, an adsorbent, a water purification agent, an ion exchange material, a catalyst, a soil improvement material, and the like as uses thereof.
[0002]
[Prior art and problems]
2. Description of the Related Art In recent years, the treatment of paper sludge, which is generated in large quantities in the paper industry, particularly in the stage of producing recycled paper from waste paper, has become a social problem. Paper sludge mainly composed of clay, which is generated in the process of making recycled paper from fibrous pulp slurry obtained by disintegrating waste paper into water, contains silica components, alumina components, and large amounts of organic substances and water It is a sludge in the form of a hydrogel, and is mostly disposed of without being used.
However, since this paper sludge contains a large amount of organic matter, it cannot be discarded as it is, and the sludge obtained after collecting and reusing pulp components from the slurry is separated and collected, dried, and then heated to a high temperature. After incineration, they are transported to a landfill or other disposal site for disposal. The amount of waste has become extremely large with the recovery of used paper, and it has become increasingly difficult to secure disposal sites. For this reason, environmental issues facing local governments, including companies that recycle waste paper, are extremely serious, and their effective use is strongly demanded as part of these measures.
[0003]
In addition, such a tendency is not limited to paper sludge, and is generally not limited to various industrial wastes and incinerated ash. In other words, the treatment status and problems of various industrial wastes and incinerated ash are almost similar to those of paper sludge. It is well known that this is one of the major concerns. Various forms of use have been proposed to solve this problem. When the modes of use are listed, for example, the use as various raw material materials such as materials for building and civil engineering, materials for cement, materials for ceramics, and materials for soil improvement is actively proposed and cited. Among them, in particular, attention has been paid to the components contained therein, that is, to the fact that silica and alumina are contained in the incineration ash, and it has been proposed to utilize this as a raw material mixture of high value-added synthetic zeolite. . The outline is introduced below.
[0004]
For example, coal ash, sewage sludge incineration, papermaking sludge, FRP combustion residues, various wastes such as iron slag, or the incineration ash thereof is added with sodium carbonate and baked at 750 to 900 ° C., and the SiO in the incineration ash ₂ And Al ₂ O ₃ Is made amorphous to contribute to the synthesis reaction of the zeolite after the acid treatment, and then subjected to an acid treatment and washing with water, followed by a hydrothermal reaction at 80 to 85 ° C. in an alkaline solution to generate zeolite. A method ”(for example, see Patent Document 1). This method targets various types of industrial waste incineration ash, which includes papermaking sludge.However, there is basically a variation in raw material components due to differences in sources, such as origin and history. In addition, when it is used as a raw material for the synthesis reaction of zeolite, it is necessary to add alkali carbonate once to sinter and burn it to secure the reactivity, and to perform a treatment such as amorphization. In addition, high cost is unavoidable in that the process operation becomes complicated and there is a problem.
[0005]
On the other hand, in the process of collecting fibers after disintegrating waste paper, the sludge containing organic matter generated by the dust removal operation is baked to remove the organic matter, and this is used as a raw material for producing zeolite. It is also reported to obtain "artificial zeolite raw material derived from waste paper and artificial zeolite derived from waste paper" (see, for example, Patent Document 2), which is heated to 80 to 90 ° C. and reacted to generate zeolite. However, the synthetic means actually disclosed therein were only in the laboratory area. That is, the production means actually disclosed uses laboratory equipment such as an Erlenmeyer flask, and it cannot be said that the production means is practically suitable for mass production. In addition, according to Patent Document 1, it is expected that the incinerated ash from which the baking treatment has been performed to remove organic matter will have poor reactivity as a reaction raw material. For this reason, in the past, a preliminary treatment was performed to increase the solubility by reacting with an alkali in advance, otherwise it would be difficult to synthesize a zeolite having a predetermined crystal structure, At about 80 to 90 ° C. disclosed, it is difficult to produce zeolite using paper sludge ash as a direct raw material. In addition, although there is a description that a material that is not fired is also used as a raw material, in this case, an organic substance is contained, and the obtained zeolite not only contains impurities by that amount, but also mentioned in the knowledge of the present invention described later. However, the carbon acts as a template and not only does not contribute to the formation of the zeolite, but may also lead to the addition of an undesired product, which is ultimately undesirable. Further, even if zeolite is produced only by maintaining the reaction temperature at 80 to 90 ° C. using the calcined material as a raw material, it has a considerably long time or contains substances other than zeolite including unreacted components. With the means and conditions disclosed therein, it is difficult to say that it provides mass-production paper sludge ash with effective mass production technology for synthesizing zeolite. I had to say that.
[0006]
In addition, a so-called aluminum sludge generated from the anodizing treatment step is heated at 80 ° C. in an aqueous solution of an alkali metal hydroxide and reacted to obtain a zeolite “Method for producing zeolite from aluminum sludge” (see Patent Document 3). Alternatively, add a diluted alkaline aqueous solution to a substance containing silicic acid and aluminum such as coal ash, incinerated ash of combustible waste, slag, aluminum dross, foundry waste sand, waste diatomaceous earth, volcanic eruption products, etc., and raise the temperature to 60 to 80 ° C. After heating, a solution portion is separated, concentrated, and then heat-treated at 100 to 300 ° C. to generate zeolite. “A method for synthesizing zeolite using a material containing silicic acid and aluminum as a raw material” (Patent Document 4) ) Is proposed, but the former is based on the aluminum dust generated in the anodizing process. There is no suggestion about using paper sludge ash as a raw material.Therefore, a method for synthesizing zeolite using paper sludge ash as a raw material cannot be considered. Absent. On the other hand, in the latter case, although papermaking sludge is included in the target waste, this method is basically based on the raw material from which the incinerated ash is derived, as in Patent Document 1. In addition to the problem that the components fluctuate, the zeolite synthesis reaction process heats the waste incineration ash in advance with an alkali solution having a predetermined concentration at 60 to 80 ° C, and removes the alkali in the raw material waste. The soluble silica component and the alumina component are extracted, concentrated to a predetermined concentration, and the part is reacted to obtain a zeolite, which involves an extremely complicated process and has a soluble There was a problem in that only a part could be used effectively.
[0007]
Further, perlite was used as a starting material, and activated Al ₂ O ₃ Alternatively, a zeolite is produced by adding a substance contained as an auxiliary material and subjecting it to hydrothermal treatment to produce zeolite, "A method for producing an artificial zeolite and a method for producing an expanded perlite" (see Patent Document 5). Aqueous solution and activated Al ₂ O ₃ In addition, there has been proposed a "method for producing an artificial zeolite" (see Patent Document 6), in which a slurry is formed by mixing with an auxiliary raw material containing, and this is autoclaved to produce an artificial zeolite. The raw materials used are those using perlite or fly ash.
[0008]
[Patent Document 1]
JP-A-7-196315
[Patent Document 2]
JP-A-11-302012
[Patent Document 3]
JP-A-11-314912
[Patent Document 4]
JP 2001-220132 A
[Patent Document 5]
JP 2002-179424 A
[Patent Document 6]
JP 2002-201021 A
[0009]
[Problems to be solved by the invention]
The present invention has been made as a conventional technique based on the techniques described in these documents.
That is, in the prior art, as a raw material for producing a synthetic zeolite, various wastes are used as raw materials, and attempts to synthesize zeolite have been proposed. As described in (0007), there is a problem in various points, and therefore, it is an object of the present invention to provide a method for synthesizing a zeolite without any problem. In addition, it aims to open the way for the effective use of paper sludge and its incineration ash, which were even distressed by the problem of securing landfill disposal sites.
[0010]
[MEANS FOR SOLVING THE PROBLEMS]
Therefore, in the present inventor, as a result of earnest research, as a raw material of silica and alumina components of zeolite, as a result of the process of recovering waste paper and producing recycled paper, incineration ash of paper sludge discharged in large quantities, so-called paper In addition to carrying out sludge ash only, by taking special measures such as processing under high temperature and high pressure in an autoclave as a reaction condition and synthesizing, uniform and similar The raw material itself is more uniform and stable in composition and properties as compared to the conventionally proposed zeolite manufacturing technology handled as a raw material, and as a result, has a specific crystal structure and quality with unique properties It has been found that stable zeolites can be mass-produced inexpensively. In addition, the zeolite after synthesis according to the present invention using ps as a raw material may contain calcium carbonate in its internal pores even if a crystallographically well-developed zeolite is obtained. In some cases, the properties of the zeolite were not always good, but even in the case of such inconvenience, by contacting with a treatment solution containing carbon dioxide, carbonate ions or calcium carbonate were efficiently produced. And found that the above problem can be solved. In other words, paper sludge and its incineration ash, which had previously been exclusively landfilled, and even those landfills, were easily converted to high value-added zeolites. It has been found that it is possible to provide an extremely practical and effective means of utilization. The present invention has been made based on these findings.
[0011]
That is, the solution means of the present invention is one in which the following requirements (1) to (18) are taken.
(1) A method for producing a synthetic zeolite, which comprises using paper sludge ash as a zeolite raw material, charging a reaction mixture into an autoclave, and causing the mixture to react by hydrothermal synthesis to produce zeolite.
(2) The synthetic zeolite according to (1), wherein the reaction mixture is prepared by using paper sludge ash as an alumina raw material, adding alkali and water thereto, and optionally mixing colloidal silica as needed. Manufacturing method.
(3) The method for producing a synthetic zeolite according to (1) or (2), wherein the reaction by the hydrothermal synthesis is performed under a high temperature and a high pressure of 100 ° C. or more.
(4) In the reaction by the hydrothermal synthesis, the step of first dissolving the paper sludge ash in the course of the reaction, and then the step of depositing crystals from the solution and growing them into predetermined crystals can be performed without changing the reaction conditions using an autoclave. The method for producing a synthetic zeolite according to any one of the above (1) to (3), wherein the method is carried out autonomously in one step.
(5) The reaction mixture has a high SiO ₂ / Al ₂ O ₃ Ratio, low Na ₂ O / Al ₂ O ₃ The method for producing a synthetic zeolite according to any one of the above (1) to (4), wherein the ratio is adjusted to generate zeolite.
(6) The reaction mixture has a low SiO ₂ / Al ₂ O ₃ Ratio, high Na ₂ O / Al ₂ O ₃ The method for producing a synthetic zeolite according to any one of the above (1) to (4), wherein the ratio is adjusted to generate zeolite.
(7) The method for producing a synthetic zeolite according to any one of (1) to (5), wherein the generated zeolite is any one of analcyme, mordenite, and ZSM-5.
(8) Any one of the above (1) to (4) and (6), wherein the zeolite to be produced is a canclinite which has pores of 5 ° or more, is stable even at 600 ° C., and can maintain its structure in water. The method for producing a synthetic zeolite according to the above item.
(9) After the zeolite is produced from the paper sludge ash, the produced zeolite is brought into contact with carbonated water to occlude and remain in the pores of the zeolite, and to remove calcium carbonate entering the zeolite synthesis process using paper sludge ash. The method for producing a zeolite according to any one of the above (1) to (8), wherein the zeolite structure is selectively eluted and removed without destroying the zeolite structure to enhance the adsorption capacity of the synthetic zeolite.
(10) The method for producing a zeolite according to the above (9), wherein the zeolite that comes into contact with carbonated water to elute and remove calcium carbonate is cancrinite.
(11) It comprises a zeolite obtained by the synthesis method described in the above (1) to (10), and is used for an application suitable for its adsorption characteristics, ion exchange ability, or high loading capacity for other components. Functional material characterized by the fact that:
(12) The functional material according to the above (11), wherein the use is exclusively provided and used as a soil improvement material.
(13) The functional material according to the above (11), wherein the use is exclusively provided and used as a water purification agent.
(14) The functional material according to the above (11), wherein the use is exclusively provided and used as a humidity control wall material (or a building material).
(15) An adsorbent composed of cancrinite obtained by the production method according to (10).
(16) An ion exchanger composed of cancrinite obtained by the production method according to (10).
(17) A fertilizer compounding material composed of cancrinite obtained by the production method according to (10).
(18) A feed compound comprising the cancrinite obtained by the production method according to (10).
[0012]
The technical constitution of the present invention is an alkali, water and, if necessary, a silica component added to paper sludge ash to prepare a reaction mixture, which is reacted in an autoclave under a high temperature and a high pressure. It is one that efficiently generates zeolite, and in addition to the processing operation by the above-mentioned configuration, for example, there is no need to react with an alkali by a calcination treatment in advance as in the prior art, or a solution dissolved in an alkali is prepared, There is no need for complicated operations such as solid-liquid separation and concentration, and a very simple and efficient synthesis method in which the steps from charging the raw materials to the autoclave and removing the generated zeolite is performed in one step is performed. To provide. Here, the paper sludge ash used in the present invention is based on a sludge containing silica and alumina obtained in a normal waste paper recycling process, and may be any sludge ash that has been separated and dried, and then fired to remove organic substances. Needless to say, paper sludge ash that has been subjected to a purification treatment for removing impurities is naturally included in this. It is preferable to remove organic substances that are not sufficiently decomposed by firing, that is, those containing considerable carbon, without using them as much as possible, or to fire again to remove carbon components. That is, in any case, the present invention is based on the process of obtaining zeolite by performing a synthesis reaction in an autoclave, starting from paper sludge ash, and includes as an embodiment of the present invention. Among them, the raw materials widely include those having an aspect not depending on the purification step to those having been subjected to the purification step.
[0013]
The autoclave used in the present invention has a container structure having a closed space when the opening / closing lid is closed, and is made of, for example, stainless steel having alkali resistance and designed to withstand high temperature and high pressure. It is. The reaction vessel was provided with a stirrer and a heater, and the reaction mixture charged in the vessel was stirred first by operating these devices, heated at a high temperature of 100 ° C. or higher, and charged in the vessel. Under the vapor pressure generated spontaneously due to the evaporation of water, the silica and alumina components, which are the main components in the paper sludge ash charged, come into contact with an alkali component or a solution containing an alkali at a high temperature and dissolve. ,react. Thereby, the reactivity is dramatically improved as compared with a case where the calcined ash in a low solubility state is simply hydrothermally reacted with an alkali under a reaction condition of about 80 ° C. to 90 ° C., and the synthesis reaction of zeolite is advantageous. Done in
[0014]
Here, the reaction mixture may be prepared as appropriate according to the type of zeolite to be obtained, and the SiO 2 in the reaction mixture may be appropriately prepared. ₂ / Al ₂ O ₃ Ratio, Na ₂ O / Al ₂ O ₃ The ratios can each be set in a fairly wide range. As a guide, a series of experiments shown in the following examples were performed, and thereby, an appropriate set guide of the reaction mixture was obtained. The results will be described later, but in summary, when a zeolite such as analcyme, mordenite, or ZSM-5 is desired, the blend design of the raw material mixture should be high SiO 2 ₂ / Al ₂ O ₃ , Low Na ₂ O / Al ₂ O ₃ And if a cancrinite-type zeolite is desired, low SiO 2 ₂ / Al ₂ O ₃ , High Na ₂ O / Al ₂ O ₃ Can be easily prepared.
[0015]
This can be further summarized as follows when the relationship between the composition ratio of the reaction mixture and the product is further described and introduced.
SiO ₂ / Al ₂ O ₃ Ratio = 20, Na ₂ O / Al ₂ O ₃ Synthesis at ratio = 3 → Mordenite and ZSM-5 formed,
SiO ₂ / Al ₂ O ₃ Ratio = 2.3-10, Na ₂ O / Al ₂ O ₃ Synthesis at ratio = 0.4-3 → mainly anal sime is formed,
SiO ₂ / Al ₂ O ₃ Ratio = 20, Na ₂ O / Al ₂ O ₃ Synthesis at ratio = 6 to 12 → Single-phase analcyme is formed,
SiO ₂ / Al ₂ O ₃ Ratio = 6.7, Na ₂ O / Al ₂ O ₃ Synthesis at a ratio of 6 to 8 → single-phase cancrinite is produced.
Of course, the relationship described above is only a rough guide, and the present invention is not limited to this. When actually producing zeolite, it is desirable to analyze the components of the paper sludge ash, grasp the optimum composition range of the reaction mixture by additional test experiments, and set the range based on this.
[0016]
The zeolite produced as described above has a structure already known per se, its properties and the like are already known, and there is no difference from those reported in known documents. That is, it is needless to say that it has the same kind of characteristics as the existing one. The zeolite obtained under the production conditions of the present invention generally exhibits uniform properties in bulk, is characterized by the size of pores and specific surface areas, and has ion exchange capacity and adsorption capacity. Of course, it is possible to obtain a crystal with higher unity by more strictly adjusting the production conditions, and thereby, it is possible to obtain a crystal of extremely high quality which requires strict separation characteristics such as a molecular sieve. Although the present invention is not limited to such a direction, the present invention is intended to facilitate the availability of raw materials and mass production, and rather, is specially manufactured at a low cost for use in relatively large quantities. However, it is better to use it, and it is considered to be a very socially significant proposal. The above-mentioned (11) to (14) are based on this concept. However, zeolite is known to have various properties in addition to those described above, and therefore, its use is versatile in itself because it is used for various purposes. It is a functional material, and all of these uses are intended in the present invention, and there is no reason to exclude a specific use. However, the reason for limiting to specific applications in (12) and (14) below is that this is described because it is particularly significant in these applications.
[0017]
As described above, according to the present invention, as described above, several types of zeolites are produced by setting and preparing a reaction mixture in a specific range for the obtained zeolite. Can be said to be a promising zeolite particularly suitable for the present invention since it has high crystallinity and can be obtained in a single phase. Therefore, it is described in (8) as one of the important aspects of the present invention.
[0018]
However, the zeolites obtained by the production method of the present invention including the above-mentioned cancrinite are caused by the paper sludge ash used as a starting material, and the produced zeolite contains calcium carbonate, and the calcium carbonate is contained in the pores. There is a serious problem that causes the various properties of the zeolite, especially the adsorption properties and the ion exchange performance to be reduced. The present inventor has also conducted intensive studies on this, and as a result, has now found a means that can solve this problem. That is, the present inventors have found out that the problem can be solved by taking the items described in (9) and (10), thereby proposing and disclosing an extremely practical and highly-completed leading technology. This means that it has great significance. In particular, it can be said that the proposal (10) relating to cancrinite has important significance in combination with the above-mentioned reason.
[0019]
In the present invention, the reason why the calcium carbonate remains in the zeolite will be described in detail later, but in any case, it is undeniable that the properties of the zeolite deteriorate as a result of the remaining calcium carbonate. Solving is also an important issue of the invention. The present inventor has further studied this phenomenon, and as a result, has developed a means for selectively separating and removing calcium carbonate from a zeolite in which calcium remains, particularly cancrinite, without destroying its structure. As described above, it has also been found that by applying and treating, the original properties of the zeolite can be recovered and developed.
As described above, the fact that PS ash is a promising material that can be used as a raw material for zeolite will be disclosed and described below based on examples.
[0020]
Hereinafter, the present invention will be described based on examples. However, these examples are disclosed only as an aid to easily understand the present invention, and are not intended to limit the present invention. 1 to 13 show X-ray diffraction patterns for identifying products obtained in Examples of the present invention.
[0021]
【Example】
Example 1;
PS ash (Shizuoka Prefecture Fuji Industrial Technology Center, SiO ₂ 29.3%, Al ₂ O ₃ 35.9%) to which SiO ₂ A reaction mixture was prepared by mixing the source, the alkali source and water. Colloidal silica (Nissan Chemical, SiO ₂ 40%, H ₂ O60%), sodium hydroxide (Wako Pure Chemical Industries, NaOH 96%, H ₂ O4%) and water used were ultrapure water.
First, a starting reaction mixture was prepared. The mixing molar ratio is as shown in Table 1 described later. The procedure for preparing this reaction mixture was prepared in advance by the number of samples for preparing the Teflon (registered trademark) container (A), and a predetermined amount of colloidal silica was weighed and prepared. On the other hand, each of PS ash, sodium hydroxide, and ultrapure water was weighed and placed in a beaker (B) made of Teflon (registered trademark), and these were thoroughly mixed in advance.
Next, the sample of (B) was placed in each of the containers of (A) and vigorously shaken for about 5 minutes to prepare a hydrogel-like reaction mixture uniformly dispersed.
The hydrogel reaction mixture was placed in a stainless steel autoclave, heated to 180 ° C., and subjected to a hydrothermal synthesis reaction for a predetermined time. After a predetermined time, the product was taken out, washed with pure water (ion-exchanged water), and dried in an air oven at 110 ° C. for 12 hours or more.
The molar ratio composition of the reaction mixture and the reaction conditions (heating temperature / time) of each sample are as shown in Table 1.
[0022]
[Table 1]

[0023]
As a result of reacting each sample shown in Table 1 by a hydrothermal reaction, the obtained product was recovered, washed, dried, and analyzed by an X-ray diffraction pattern. The result was an X-ray diffraction pattern as shown in FIGS. 1 to 13 below.
[0024]
FIG. 1 shows X-ray diffraction patterns of ps-1 and ps-2. As a result of the analysis, it was clarified that mordenite or ZSM-5 type zeolite belonging to a five-membered ring structure was produced under this blending design and reaction conditions. The starting composition was based on a formulation design in which mordenite was easily formed, but in addition to mordenite, ZSM-5 was slightly produced as a by-product. This is considered that both mordenite and ZSM-5 are zeolites composed of a five-membered ring, and the synthesis conditions are similar, so that ZSM-5 was also formed. Further, it is considered that the carbon component and the like included in the PS ash serve as a template, and this has also caused the partial generation of ZSM-5.
As a countermeasure, that is, in order to obtain a single-phase product, the paper sludge ash to be used should be one from which carbon has been further removed. It is considered that taking measures such as reacting to the situation is an effective means.
[0025]
In addition, this example includes a case where a plurality of zeolites are generated in the generated zeolite depending on the reaction conditions, as in the example shown in ps-2. As long as there is no problem in practical use, the present invention is a useful invention, and it is a matter of course that the present invention is an invention which can be used industrially. That is, in the case of a synthetic zeolite, it is common that a multi-phase zeolite is generated. Except when extremely strict physical properties are required for applications, for example, a soil conditioner, a deodorant, a desiccant, etc. When used in ordinary applications that do not require such strict physical properties, such as, etc., there is no practical problem even if multi-phase zeolite is mixed in and by-produced, and paper sludge ash, which is the intended purpose, is added Needless to say, the purpose of converting to one having high-valued physical properties has been achieved.
Of course, it goes without saying that the desire for a more pure single phase is included. The present embodiment discloses its probability and provides its pioneering significance.
[0026]
Next, the product produced by the blending design and reaction conditions described in ps-3 and ps-5 had an X-ray diffraction pattern as shown in FIG. Upon identification, it was confirmed that both analsyms were formed. Compared with ps-1 or ps-2, the addition of a large proportion of PS ash, which is an Al component, facilitated the formation of a four-membered ring and a six-membered ring, and mainly produced analsim.
[0027]
Next, FIG. 3 shows an X-ray diffraction pattern of the product produced by the formulation and reaction conditions described in ps-6 and ps-7 and an X-ray diffraction pattern of PS ash itself for comparison. The results revealed that cancrinite was formed in these samples. However, it was also clarified that the paper sludge ash did not react and was partially mixed. It is considered that the reason for this is that PS ash, which is an Al component, was larger than the composition of ps-5, so that the PS ash did not dissolve and remained unreacted. In the composition design of ps-6 and ps-7, the molar ratio of water was doubled, and the influence of the amount of water was observed. However, almost no change was observed from the X-ray diffraction pattern. In this case, no effect of water on the composition design was observed.
[0028]
Next, FIG. 4 shows the X-ray diffraction pattern of the product produced by the formulation and the reaction conditions described in ps-9 and ps-19 and the X-ray diffraction pattern of PS ash itself for comparison. The results showed that analsym was formed in these samples. However, mixing of unreacted components considered to be derived from PS ash and weak peak intensity make it difficult to identify clearly, but some weak peaks, which are considered to be mordenite or heurandite, were also observed. The X-ray diffraction pattern showed that, similarly to ps-7, PS ash blended as an Al component was not partially dissolved but remained as an unreacted component. It is probable that in these samples, the alkali component was less than the amount required to dissolve the PS ash. Further, by increasing the Si component more than ps-6 and ps-7, the area outside the cancrinite generation region was rather deviated, which is considered to be the cause of the formation of analcyme and the inability to generate cancrinite.
[0029]
Next, the X-ray diffraction pattern of PS ash itself for comparison with the X-ray diffraction pattern of the product generated by the formulation design and reaction conditions described in ps-10, ps-11, ps-12, and ps-13 FIG. 5 shows the X-ray diffraction pattern of ps-5. As a result, it was clarified that an anal syme was formed from these samples. Among them, it was confirmed that the crystallization of the product of ps-10 was most advanced. In addition, although a weak peak of unreacted PS ash was partially confirmed, it is considered to be within a range in which there is no problem in practical use. It is considered that the reason for this is that, as in the case of ps-9, a large amount of PS ash was added as an Al component, so that the alkali component was not sufficient to dissolve the PS ash. The peaks of mordenite, ZSM-5, and cancrinite were not observed in ps-1 to ps-9 and ps-19. It is considered that the reason is that the Si component is relatively reduced by increasing the PS ash used as the Al component, and components such as mordenite are suppressed.
[0030]
Next, the X-ray diffraction pattern of ps-1 set shorter than the reaction time in these samples for comparison with the X-ray diffraction patterns of the products produced by the formulation design and reaction conditions described in ps-16 and ps-18 Are shown in FIG. That is, in these samples, the composition of ps-1 was the same, but the synthesis was performed twice as long as the synthesis time to 96 hours. The effect of increasing the synthesis time was investigated. In other words, it was considered that mordenite or ZSM-5 was formed in a single phase, but a slight change in the intensity ratio showed a significant difference. Did not. In the synthesis of zeolite from PS ash, the dissolution of PS ash is an essential condition, but in the case of the comparative experiment of this example, it was not possible to sufficiently improve the solubility by simply extending the reaction time. .
[0031]
Next, FIG. 7 shows an X-ray diffraction pattern of a product produced by the formulation and reaction conditions described in ps-17 and ps-22. In the sample example of ps-17, an anal syme was formed. In the ps-17 formulation, the molar ratio composition of the reaction mixture of ps-9 was set to be the same, and the synthesis time was set to be twice. In this case, the prolongation of the reaction time was advantageous. By extending it twice, it was possible to obtain an anal sim with developed crystals.
On the other hand, ps-22 revealed that cancrinite was produced as a by-product in addition to analcyme. In the ps-22 formulation, the Na ratio was increased compared to the composition of ps-19, so that the solubility of PS ash was improved, and other crystal nuclei grew in addition to analcyme, thereby producing cancrinite. It is considered.
[0032]
Next, FIG. 8 shows an X-ray diffraction pattern of a product generated by a blending design and a reaction condition based on a high alkali content described in ps-21 and ps-23. As a result, it was clarified that anal sime was formed in both samples. The ps-23 compounded with a high alkali content with the alkali content set to be twice as large as the ps-21 with the lower alkali content, except for a small amount of other than analsim, but by-products. Was. Since the composition of ps-21 was synthesized by doubling the Na ratio of the composition of ps-1, the dissolution of PS ash was promoted, and the Al component effectively participating in the reaction increased, resulting in a 6-membered ring. It is easier to do, and it is thought that anal sim was generated. And, in ps-23, it is considered that by increasing the alkali component, the number of factors for forming a skeleton other than the anal cyme increased, and this also led to by-products other than the anal syme.
[0033]
Next, FIG. 9 shows an X-ray diffraction pattern of a product under the formulation and reaction conditions shown in ps-24, ps-28 and ps-29 set to a high alkali content. As a result, it was revealed that ps-24 had cancrinite as a main component and an analcime was formed as a by-product in this. It is considered that in this sample, the zeolite that grew as analcyme was recrystallized into cancrinite by further increasing the Na ratio to twice that of the composition of ps-22. Canclinite was formed in ps-28 and ps-29. It is considered that as a result of increasing the Na ratio from ps-24, the solubility of PS ash was increased and canclinite with better crystallinity was generated.
[0034]
Next, the X-ray diffraction pattern of the product under the formulation and reaction conditions shown in ps-26 and ps-27 is shown in FIG. In each case, the composition was set the same, and the reaction temperature of ps-27 was set higher by 10 ° C. As a result, there was no fundamental difference between the two, and analcyme was generated. The starting compositions of the two were the same as those of ps-21, but in each case, a gel-like portion and a hard-hardened portion were formed after the reaction was completed. In ps-21, the gel portion and the solid portion were combined, filtered, washed, dried, and subjected to X-ray diffraction measurement. On the other hand, ps-26 and ps-27 were separately measured by suction filtration into a gel-like portion and a non-gel-like solid portion. From the X-ray diffraction pattern, it became clear that the peak was shifted to a higher angle in the gel-like part than in the hard part. This is considered to be due to the fact that the Si portion was larger in the gel-like portion, and thus the lattice constant was reduced (see Table 2). When crystallization of zeolite is performed as a cause, crystallization starts from a high temperature (outside the vessel), and finally the center of the vessel is crystallized. It is considered that the gel-like portion was crystallized by colloidal silica added as a Si component and slightly dissolved PS ash, so that an anal sim incorporating a large amount of the Si component was generated. Thereafter, it is presumed that the PS component was dissolved with time, the Al component increased, and a solid portion was formed.
[0035]
[Table 2]

[0036]
Reference Example 1;
Next, zeolite synthesis was attempted using a waste liquid (provided by Fuji Industrial Technology Center) obtained when the PS ash was subjected to alkali treatment as a mother liquor and faujasite as a seed crystal.
20 g of the waste liquid and 0.2 g of the seed crystal were weighed, combined, inserted into an autoclave, and reacted under the conditions shown in Table 3.
[0037]
[Table 3]

[0038]
As a result, an X-ray diffraction pattern as shown in FIG. 11 was obtained. Table 3-2 shows the lattice constants of ps-14 and ps-15. By using faujasite (F-9) as a seed crystal, the resulting product was produced by faujasite. Comparison of the lattice constants (Table 4) shows that ps-14 crystallized after reacting for 24 hours. ₋₂₄ And ps-15 ₋₂₄ Then, it became larger than that of the original faujasite, whereas it became smaller in the sample crystallized for 48 hours. This is considered to be due to the fact that a large amount of the Al component was taken in from the early stage to the middle stage of the crystallization, and the amount of the Si component taken up increased as the Al component in the mother liquor decreased, resulting in a change in the lattice constant. However, since the difference between the lattice constants is small and the amounts of the Al and Si components contained in the mother liquor are as small as mg / l, the significance and usefulness of using this alkaline waste liquid could not be found. .
[0039]
[Table 4]

[0040]
Reference Example 2;
Next, since paper sludge ash is hardly dissolved in alkali, it was treated with hydrofluoric acid to try to use it as a starting material. That is, after adding 20 ml and 30 ml of hydrofluoric acid and stirring for several minutes, the mixture was neutralized with aqueous ammonia (the former was shown as sample ps-01 and the latter was shown as sample ps-02), and a reaction mixture was prepared using this as a sample. And zeolite synthesis. The reaction conditions are as shown in Table 1 above. _-1 , Ps-4 _-2 It is shown by.
As a result, an X-ray diffraction pattern as shown in FIG. 12 was obtained. That is, since ps-01 and ps-02 have been treated with hydrofluoric acid, the Si component contained in the ash reacts with hydrofluoric acid, and then reacts with ammonia by neutralization to form ammonium hexafluorosilicate. did. In ammonium hexafluorosilicate, the reactivity of silicon to the tetra-coordinate state required for the zeolite skeleton is impaired because fluorine is coordinated to silicon in the form of six atoms. _-1 , Ps-4 _-2 Is considered to have become amorphous, and in any case, in the case of using zeolite as a raw material for zeolite with increased alkali solubility of paper sludge ash, there is a certain selectivity there, and it is effective by any means. Since it is not always the case, it is necessary to confirm it by an experiment in advance, and it is more preferable.
[0041]
From the above results, it was confirmed that it is sufficiently possible to obtain synthetic zeolite by using paper sludge ash as a raw material for synthesizing zeolite without prior treatment and performing hydrothermal synthesis in an autoclave. The significance of this method is extremely large because the raw material used is based on what has been discarded, based on a process that can be operated on an industrial scale, and the like. In other words, for the local governments and other related organizations where the paper industry related to waste paper is located, the present invention increases the added value of those that were originally poorly disposed of as waste. In other words, it has the meaning of creating new industries and providing opportunities for revitalization of the region, which is directly linked to extremely powerful regional development, has a great impact on the local economy and economic and technical It is expected to have a ripple effect.
According to the present invention, the formulation of the starting reaction mixture using paper sludge ash is based on the knowledge based on the above experiments, and as a rough guide, when aiming at mordenite or ZSM-5, the SiO2 is obtained from the above experiments. ₂ / Al ₂ O ₃ Molar ratio of 20, Na ₂ O / Al ₂ O ₃ It is preferable to set the molar ratio to about 3.
When aiming for anal sim, use SiO ₂ / Al ₂ O ₃ Ratio = 2.3-20, Na ₂ O / Al ₂ O ₃ The ratio is preferably 0.4 to 12, and particularly preferably SiO 2 ₂ / Al ₂ O ₃ Ratio = 20, Na ₂ O / Al ₂ O ₃ The ratio is preferably in the range of 6 to 12.
When aiming at single-phase cancrinite, SiO ₂ / Al ₂ O ₃ Ratio = 6.7, Na ₂ O / Al ₂ O ₃ A ratio of 6 to 8 is a preferable range. As mentioned above, the specific working conditions are almost specified, and it can be said that the present invention provides a highly-completed zeolite manufacturing technique that enables the desired zeolite to be manufactured with repetitive reproducibility.
[0042]
Next, in order to consider the thermal or chemical stability of ps-29, which had a remarkable effect on the development of crystals as a result of the examples shown above, various treatments described below were performed. In order to investigate the influence of the crystal structure, an investigation was again performed using an X-ray diffraction pattern. As a result, no destruction of the crystal structure was observed in the heat-treated sample ps-29-2 and the ps-29-3 treated with ion-exchanged water.
The crystal state of the synthesized cancrinite was good, but it was found that the adsorbability and the like were sometimes difficult. Therefore, further research was conducted to solve this problem.
[0043]
As a result of diligent research into the cause, it has been found that in the zeolite production process, carbonate ions serve as templates, which are retained in the pores in association with calcium ions, reducing the adsorption capacity. Was. Therefore, some basic or typical treatments are performed to improve the function of the synthetic zeolite, resulting in the improvement of the zeolite's function and its effect on the ability to maintain the structure of the zeolite. investigated.
Both ps-29-4, which was treated with 0.1 N hydrochloric acid to remove the Ca component, and ps-29-2, which had been ammonium-exchanged and heat-treated, were both amorphous. did. The Na component was replaced with ammonium using TMACl and then calcined ps-29-6 did not break its pore structure. From the above, it has been found that the zeolite (canclinite) according to the present invention causes skeletal destruction when exposed to an acidic atmosphere. The results are as shown in the X-ray diffraction pattern shown in FIG.
[0044]
Also, samples of ps-1 (mordenite), ps-9 (analcime), ps-29-1 (cancrinite), ps-29-2 (cancrinite), ps-29-6 (cancrinite), and PS ash Was examined for nitrogen adsorption characteristics. As a result, an adsorption isotherm at 77 K shown in FIG. 14 was obtained. FIG. 15 shows a DR plot prepared from the adsorption amounts of ps-1 and ps-9, ps-29-1, ps-29-2, and ps-29-3, and FIG. 16 shows a BET plot. Table 5 shows the saturated adsorption amount, specific surface area and water content, and Table 6 shows the saturated adsorption amount of mordenite.
The saturated adsorption amount of ps-1 was about one third of the saturated adsorption amount of commercially available mordenite. This is considered to be due to the poor crystallinity of PS-1 and the unreacted PS ash remaining.
[0045]
ps-9 is a mixture of predominantly unreacted PS ash and by-products which are considered to be analcyme and mordenite or hulandite. Anal Sim is N ₂ Since the pores are smaller than the molecular diameter, nitrogen cannot be adsorbed. However, a rise in the adsorption amount at the initial stage of the adsorption was observed, suggesting that micropores were present. From the X-ray diffraction pattern, a peak that is considered to be either hulandite or mordenite appears, and it is considered that these peaks are adsorbed to these by-products.
Since ps-29-1 was cancrinite, adsorption measurement was performed, but the adsorption performance was not better than ps-9. Canclinite has 5.9% pores, but CaCO ₃ It is believed that no practical adsorption amount was shown because of the residual. In addition, CaCO ₃ Cannot be removed by ion exchange, so N ₂ Cannot be adsorbed.
[0046]
In the case of ps-29-2, ps-29-1 was further washed and adsorption measurement was performed. ₃ It could not be easily removed, and no significant improvement in adsorption performance was observed. However, although Ca was removed though a trace amount from ps-29-1, the pore volume itself increased. ps-29-6 is a sample fired after ammonium exchange. As a result of the adsorption measurement, it showed almost the same value as ps-29-2. Thereby, even if ammonium exchange is performed, CaCO ₃ It is probable that it was not adsorbed because it could not be removed.
[0047]
[Table 5]

[0048]
[Table 6]

[0049]
FIG. 17 shows the relationship between the starting composition and the products summarized and summarized for all the samples.
Referring to FIG. 17, it was found that analsim was formed in the entire starting composition. High SiO ₂ / Al ₂ O ₃ And low Na ₂ O / Al ₂ O ₃ In the above, zeolite having a five-membered ring of mordenite or ZSM-5 was formed because an odd-numbered ring was easily formed.
Conversely, low SiO ₂ / Al ₂ O ₃ And high Na ₂ O / Al ₂ O ₃ Since it is easy to form even-numbered rings at this point, it is considered that zeolites having 4- or 6-membered rings, that is, cancrinite, were formed. When the Na component is low, the PS ash does not dissolve, so that zeolite with good crystallinity is not generated. When the Na component is high, the PS ash is likely to be easily melted and a four-membered ring or a six-membered ring is likely to be formed.
From the results of the nitrogen adsorption measurement, the mixture of mordenite and ZSM-5 exhibited practically sufficient values for both the specific surface area and the pore volume. Although cancrinite did not exhibit the expected amount of adsorption, CaCO remaining in the pores remained due to the formation of single-phase zeolite. ₃ If it could be removed, the practicality would be further improved, and it would greatly contribute to the development of industry.
As a result, CaCO ₃ Was selectively separated and removed, and it was confirmed and confirmed that the inherent properties of zeolite, which is generally known for its adsorption characteristics and ion exchange ability, were exhibited.
[0050]
Here, it is considered that the model in which calcium carbonate remains in the zeolite and the reason for the remaining are as follows.
FIG. 18 shows the basic skeleton of cancrinite immediately after synthesis. Although cancrinite has one-dimensional pores with a diameter of 5.9 mm, crystals grow using carbonate ions as a template, and the carbonate ions are bound to calcium at the pore positions to be formed, and remain. Therefore, it is considered that these properties greatly affect various properties such as an effective specific surface area and adsorption characteristics. The one-dimensional pore further has a cavity (not shown) in the pore wall, and calcium ions (Ca ²⁺ ) Is present and keeps the charge balance with the carbonate ion entered as the template, thereby filling the pores which are one of the important features of the zeolite, and having various properties including the original adsorption function. Thus, it is considered that zeolite whose expression was suppressed was produced.
[0051]
The above is considered to be the cause of the calcium carbonate filling the pores of the zeolite. In particular, among the synthetic zeolites according to the present invention, it was typical in canclinite where the development of crystals was most remarkable. It is presumed that carbonate ions and calcium ions acted as templates during the crystal formation process in the pores in the structure for the reasons described above, and were trapped and remained in the pores as a result. This is considered to be the reason why various properties did not appear as expected despite the remarkable development of the crystal. The present inventor has further studied this phenomenon as described above, and as a result, a means for selectively separating and removing calcium carbonate from zeolite in which calcium carbonate remains, particularly cancrinite without destroying its structure. It has been found that by developing, applying and treating this means, the original properties of zeolite can be restored and developed. A series of experiments described below specifically discloses the above-mentioned solution, that is, the solution corresponding to the present inventions (9) and (10), and clarifies the effectiveness of this solution. .
[0052]
[Experiment 1] FIG. 19 (a) shows a model in which carbonate ions were removed from the cancrinite shown in FIG. 18 synthesized from paper sludge ash in the above embodiment without destroying its skeletal structure. It is shown. In this experiment, cancrinite was washed with an alkaline solution to remove calcium carbonate. As the prepared alkaline solution, 3N, 6N, 9N, and 12N (N represents a specified concentration) sodium hydroxide aqueous solutions were prepared, 25 ml of the solution was placed in a 30 ml Teflon container, and 1 g of the synthesized cancrinite sample was added thereto and sealed. . The Teflon container was placed in a 383 K air bath, heat-treated for 12 hours, and then allowed to cool at room temperature for 1 hour. The sample after the treatment was washed with about 1 liter of ion-exchanged water and dried, and the structure was confirmed by X-ray diffraction measurement. FIG. 19B shows an X-ray diffraction pattern of the sample after the treatment with the alkaline solution. For reference, an X-ray diffraction pattern of a canclinite sample before treatment and PS ash itself as a synthetic raw material are also shown. As a result, those treated with 3N and 6N showed the same diffraction pattern as the sample before the treatment, little change was recognized by the treatment, and it was found that carbonate ions could not be removed at these concentrations. In the 9 and 12 N treatments with further increased concentrations, a change was observed in the X-ray diffraction pattern compared to the sample before treatment. In order to confirm the structure from these diffraction patterns, a comparison was made with the diffraction pattern of PS ash, which is a synthetic raw material. As a result, although the pattern was not exactly the same, the result of returning to the raw material PS ash by the alkali treatment was obtained. Not limited to zeolites, the crystallization phenomenon is a reversible reaction between the reaction mixture and the product and is in equilibrium. The processing conditions in this case are conditions that cause a reverse reaction of crystallization, and it is considered that PS ash as a raw material was generated.
As described above, the washing treatment with an alkaline solution is a treatment expected to remove carbonate ions by ion exchange between carbonate ions and hydroxide ions, but as a result, a reverse reaction of crystallization occurs and carbonate ions (calcium carbonate) It became clear that it was not suitable for removal of salt).
[0053]
[Experiment 2] Since it was found that the carbonate treatment could not be removed by the cleaning treatment with the alkaline solution shown in Experiment 1, the cleaning treatment was performed using carbonated water in which carbon dioxide was dissolved in water. It is known that calcium carbonate does not dissolve in water, but dissolves in water (carbonated water) containing excess carbon dioxide as hydrogen carbonate ions. Therefore, the sample was agitated while bubbling carbon dioxide to remove carbonate ions.
The processing conditions were as follows: 1 g of a sample was dispersed in 100 ml of water, and carbon dioxide was bubbled at a rate of one bubble per second while stirring with a stirrer. The bubbling time was varied from 6 to 48 hours. After the treatment, the structure was washed with about 1 liter of ion-exchanged water and dried, and the structure was confirmed by X-ray diffraction measurement.
FIG. 20 (a) is a conceptual view of an embodiment showing these processing modes, and FIG. 20 (b) shows an X-ray diffraction pattern of a sample zeolite (cancrinite) after the processing.
From the X-ray pattern, two peaks around 7.5 ° and around 30 ° (vertical lines in the figure) showed a remarkable change with the processing time. However, the other peaks hardly changed, indicating that the skeletal structure was basically maintained. In X-ray diffraction measurement, a peak derived from a plane connecting regularly arranged atoms appears. The peak around 7.5 ° is a diffraction peak of (100), and indicates a peak derived from carbonate ions. The (100) peak derived from the carbonate ion disappeared with an increase in the treatment time of the carbonated water washing, indicating that the carbonate ion was removed over time with the treatment time. In this experiment, it disappeared after 12 hours. In addition, two peaks around 30 ° indicate a combined peak (structurally equivalent) of (310) and (130) on the low angle side, and a peak of (301) on the high angle side. In particular, a calcium ion exists at the position of the peak on the low angle side. These peaks become one with the processing time. Particularly, the peaks of (310) and (130) disappeared, and only the peak of (301) disappeared, indicating that the carbonate ion and the calcium ion for charge compensation were removed. From this experiment, it has been clarified that washing with carbonated water is a very suitable method for removing occluded and remaining carbonate ions and calcium carbonate without destroying the structure of the synthetic zeolite.
[0054]
[Experiment 3] This experiment is for observing and clarifying how the properties of zeolite are changed and affected by the carbonated water washing treatment, and how the properties are improved in the present invention. In this experiment, a nitrogen gas adsorption isotherm survey used in evaluating the adsorption characteristics of zeolite was adopted as an observation index for that purpose.
The results of this experiment are shown in FIG. As a result, it was revealed that nitrogen was scarcely adsorbed in the synthetic cancrinite due to the presence of carbonate ions in the pores. However, after the washing with carbonated water, a sharp increase in the amount of adsorption was observed in the low-pressure part peculiar to the micropores, and an isotherm in which nitrogen was adsorbed in the pores. Both adsorption isotherms have relative pressures (P / P ₀ ) Exceeds 0.8, the amount of adsorption increases, but this indicates that the particles are adsorbed in the gap between the particles, and is not adsorption derived from cancrinite.
The value of the specific surface area of cancrinite after washing with carbonated water is 124 m ² / G. It was found to have a sufficient specific surface area as an adsorbent. When the pore volume was determined from a DR-plot in a region where the pores were completely filled with nitrogen (circled region in the figure), the value was 0.113 ml / g. . Since cancrinite has 5.9 A one-dimensional pores, the volume per gram was estimated to be 0.099 ml / g, assuming that it was a perfect cylinder. As a result, when the two were compared, they showed almost similar values, indicating that the cancrinite structure was retained and the carbonate ions were removed. In addition, the measured value is slightly larger, which is due to the fact that nitrogen is also adsorbed in the depression of the pore wall where calcium ions originally exist. It is thought.
[0055]
[Experiment 4] In this experiment, how the ion exchange capacity, which is one of the properties of the zeolite, was changed and affected by the carbonated water washing. It aims to clarify how the exchange capacity is improved.
First, a 50 ml Erlenmeyer flask was prepared, and 17 mmol / dm. ³ An aqueous solution of lead nitrate was sampled in 20 ml portions, and 1.0 g of a sample after removing calcium carbonate was added. Shake every 6 hours for 48 hours, then filter and separate into solid and liquid phases.
5 ml of the liquid phase was taken, about 150 ml of water was put into a conical beaker, a few drops of bromothymol blue indicator were added, and aqueous ammonia (1 + 1) was added with a Pasteur pipette until the solution turned from yellow to blue. 4 ml of sodium acetate-acetic acid buffer was added, and about 5 drops of xylenol orange indicator were added.
5 mmol / dm ³ The concentration of lead was determined by EDTA titration. The concentration was calculated using 17 mmol / dm ³ A calibration curve was prepared using a lead nitrate aqueous solution and a solution obtained by diluting the solution to 20%, 40%, 60%, and 80%, and the calibration curve was obtained. The solid phase was washed with about 500 ml of ion-exchanged water, dried, and subjected to X-ray diffraction measurement and EDS composition analysis.
FIG. 22 shows the change over time in the solution concentration in the lead ion exchange. The solution concentration decreased up to 12 hours after the ion exchange, but no change was observed in the concentration thereafter. The difference (DC) between the initial concentration and the concentration when the concentration becomes constant for 12 hours or more corresponds to the amount of concentration change when 100% of the ion-exchangeable cation (Na +) of cancrinite is replaced by lead ions. are doing. Normally, 100% ion exchange does not occur even if other exchangeable ions are present in the solution in a large excess with respect to the amount of cations of the zeolite. However, since cancrinite from which carbonate ions had been removed had 100% exchange, it was clear that it had ion exchange ability selective for lead ions.
For cancrinite from which carbonate ions have not been removed (synthetic cancrinite), the passage of ions is blocked by the presence of carbonate ions in the pores, and ion exchange does not show a significant value. The ion exchange performance of the zeolite was hardly exhibited.
[0056]
From the above results, it is clear that so-called carbonated water containing excessive carbon dioxide gas is an extremely effective means for improving the function of synthetic zeolite containing carbonate ions and calcium carbonate in the pores. Became. As a result, the method for producing a zeolite using ps ash according to the present invention can be further raised to a more practical level, providing an industrially significant means and greatly contributing to industrial development. Be expected.
[0057]
【The invention's effect】
By using paper sludge ash that has been mainly disposed of until now and treating it under high-temperature and high-pressure conditions in an autoclave, it has become possible to produce high-value-added zeolite. In itself, it is of great significance. According to the present invention, only by knowing the composition in advance, the amount of colloidal silica to be added can be adjusted, and a zeolite having a high purity and uniform composition can be obtained without depending on the lot of paper sludge ash. The control and regulation of the process is extremely simple and provides a means suitable for mass production as compared with the conventional synthesis methods that depend on various waste systems. It is considered to have been provided. In particular, the fact that canclinite includes a mode in which cancrinite having pores of 5 ° or more can be obtained in a single phase is particularly worthy of evaluation because it provides a high value-added material. In addition, other than paper sludge ash, alkali and colloidal silica added at the time of synthesis are inexpensive at several hundred yen per kg, and the heat energy required for synthesis can be obtained by using a heat source generated when firing paper sludge. In addition, the paper sludge ash can be recycled with a simple capital investment, and the effect of providing the zeolite production method which is extremely superior to the conventional method is extremely significant, including the effect. In addition, it was possible to provide a means for easily removing calcium carbonate entering during the process of forming zeolite crystals by a simple operation of contacting with carbonated water. In combination with the provision of a means for synthesizing a certain zeolite, it is considered to be extremely significant to contribute to industrial development.
[Brief description of the drawings]
FIG. 1 is a view showing an X-ray pattern of zeolite produced by samples ps-1 and ps-2 of an example.
FIG. 2 is a view showing an X-ray pattern of zeolite produced by samples ps-3 and ps-5 of an example.
FIG. 3 is a diagram showing an X-ray pattern of zeolite generated by samples ps-6 and ps-7 of the example and an X-ray pattern of PS ash itself.
FIG. 4 is a diagram showing an X-ray pattern of zeolite produced by samples ps-9 and ps-19 of the example and an X-ray pattern of PS ash itself.
FIG. 5 is a diagram showing an X-ray pattern of zeolite generated by samples ps-10, ps-11, ps-12, and ps-13 of the example and an X-ray pattern of PS ash itself.
FIG. 6 is a diagram showing an X-ray pattern of zeolite produced by samples ps-16 and ps-18 of the example and an x-ray pattern of ps-1 for comparison.
FIG. 7 is a view showing an X-ray pattern of zeolite produced by samples ps-17 and ps-22 of the example.
FIG. 8 is a view showing an X-ray pattern of zeolite produced by samples ps-21 and ps-23 of the example.
FIG. 9 is a view showing an X-ray pattern of zeolite produced by samples ps-24, ps-28 and ps-29 of the example.
FIG. 10 is a view showing an X-ray pattern of zeolite produced by samples ps-26 and ps-27 of the example.
FIG. 11 shows ps-14 starting from a waste liquid obtained by alkali-treating PS ash described in Reference Example 1. ₋₂₄ , Ps-14 _-48 , Ps-15 ₋₂₄ , Ps-15 _-48 FIG. 3 is a view showing an X-ray pattern of zeolite generated by the method described above and an X-ray pattern of faujasite (F-9) used as a seed crystal.
FIG. 12 is a diagram showing an X-ray diffraction pattern of a product synthesized based on hydrofluoric acid treatment shown in Reference Example 2, and an X-ray diffraction pattern of a product neutralized after hydrofluoric acid treatment.
FIG. 13 is a diagram showing an X-ray diffraction pattern after performing various treatments on a product shown in ps-29 and investigating the influence thereof.
FIG. 14 is a diagram showing adsorption isotherms of ps-1, ps-9, ps-29-1 and ps-29-2.
FIG. 15 is a diagram showing DR plots of ps-1, ps-9, ps-29-1 and ps-29-2.
FIG. 16 is a diagram showing BET plots of ps-1, ps-9, ps-29-1 and ps-29-2.
FIG. 17 shows a summary of the correlation between the starting composition and the product.
FIG. 18 is a view showing a crystal structure model of a synthetic zeolite (cancrinite) obtained using paper sludge ash as a raw material and having carbonate ions in pores.
FIG. 19 shows (a) a crystal model of synthetic zeolite (cancrinite) after carbonate ion removal treatment, and (b) an XRD pattern of zeolite showing the effect of the alkali solution washing treatment.
FIG. 20 is a conceptual diagram of an embodiment showing (a) carbonated water treatment, and (b) an XRD pattern of synthetic zeolite (cancrinite) showing the influence of the carbonated water treatment.
FIG. 21 (a) is a diagram showing the nitrogen adsorption value of synthetic zeolite (cancrinite) and the pore volume of zeolite (calculated value and experimental value), which represent the effects of carbonated water treatment.
FIG. 22 is a view showing a lead ion exchange test result of a synthetic zeolite (cancrinite) showing the influence of the carbonated water treatment.

Claims (18)

A method for producing a synthetic zeolite, comprising using paper sludge ash as a zeolite raw material, charging a reaction mixture into an autoclave, and reacting the mixture with hydrothermal synthesis to form zeolite. The method for producing a synthetic zeolite according to claim 1, wherein the reaction mixture is prepared by using paper sludge ash as an alumina raw material, adding an alkali and water thereto, and optionally mixing colloidal silica as needed. The method for producing a synthetic zeolite according to claim 1, wherein the reaction by the hydrothermal synthesis is performed under a high temperature and a high pressure of 100 ° C. or more. The reaction by the hydrothermal synthesis is a step of first dissolving the paper sludge ash in the course of the reaction, then depositing crystals from the solution and growing them into predetermined crystals, without changing the autoclave reaction conditions, autonomously. The method for producing a synthetic zeolite according to any one of claims 1 to 3, wherein the method is performed in one step. The zeolite according to claim 1, wherein the reaction mixture is adjusted to a high SiO ₂ / Al ₂ O ₃ ratio and a low Na ₂ O / Al ₂ O ₃ ratio to form a zeolite. A method for producing the synthetic zeolite as described above. The reaction mixture is low _SiO 2 / _Al 2 _{O 3} ratio is adjusted to the high _Na 2 O / _Al 2 _{O 3} ratio and generates a zeolite, in any one of claims 1 to 4 A method for producing the synthetic zeolite as described above. The method for producing a synthetic zeolite according to any one of claims 1 to 5, wherein the generated zeolite is any one of analcyme, mordenite, and ZSM-5. The production of the synthetic zeolite according to any one of claims 1 to 4, wherein the zeolite to be produced is cancrinite having pores of 5 ° or more, stable at 600 ° C, and capable of maintaining its structure in water. Method. After the zeolite is produced from paper sludge ash, the produced zeolite is brought into contact with carbonated water to occlude and remain in the zeolite pores.The calcium carbonate that enters the zeolite synthesis process using paper sludge ash is converted into a zeolite structure. The method for producing a zeolite according to any one of the above (1) to (8), wherein the zeolite is selectively eluted and removed without destroying the zeolite to enhance the adsorption capacity of the synthetic zeolite. 10. The method for producing zeolite according to claim 9, wherein the zeolite that comes into contact with carbonated water and elutes and removes calcium carbonate is cancrinite. It comprises a zeolite obtained by the synthesis method according to any one of claims 1 to 10, and is used for an application suitable for its adsorption property, ion exchange capacity, or high loading capacity for other components. Functional materials. The functional material according to claim 11, characterized in that the use is exclusively provided and used as a soil improvement material. The functional material according to claim 11, wherein the use is exclusively provided and used as a water purification agent. The functional material according to claim 11, characterized in that said use is exclusively provided and used as a moisture-controlling wall material (or building material). An adsorbent composed of cancrinite obtained by the production method according to claim 10. An ion exchanger comprising cancrinite obtained by the production method according to claim 10. A fertilizer compounding material comprising cancrinite obtained by the production method according to claim 10. A feed compound comprising the cancrinite obtained by the production method according to claim 10.

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