JP3995169B2

JP3995169B2 - Method of spraying dense and irregular shaped refractories

Info

Publication number: JP3995169B2
Application number: JP14112997A
Authority: JP
Inventors: 勝也斧; 敏彦武重
Original assignee: 大光炉材株式会社
Priority date: 1997-05-16
Filing date: 1997-05-16
Publication date: 2007-10-24
Anticipated expiration: 2017-05-16
Also published as: JPH10316478A

Description

【０００１】
【発明の属する技術分野】
本発明は取鍋、タンディッシュ、樋等の溶融金属容器及び雰囲気炉の内張り材として使用される緻密質不定形耐火物の吹付け施工法に関する。
【０００２】
【従来の技術】
近年、流し込み材の耐用性が向上するにつれて溶融金属容器の内張り材は、煉瓦から施工が容易な流し込み材へと移行してきている。しかし省力化に関して、流し込み施工法にはまだ枠掛け作業が煩雑であるという問題点がある。その点、吹付け施工法は型枠が不要で応急かつ局部的補修が可能なため、一段と省力化に寄与するとともに補修計画に対しても柔軟な対応ができる。そのため吹付け施工法は増加の傾向にある。
【０００３】
吹付け施工法には乾式吹付け法、半乾式吹付け法及び湿式吹付け法がある。
【０００４】
乾式吹付け法は不定形耐火物の粉体を吹付けノズルの先端まで圧搾空気で搬送し、ノズル部で水を添加して吹付ける方法である。この方法は混練用ミキサ−が不要で、使用後の清掃が簡便である等の利点はあるが、ノズル内での粉体と水の混合が不均一になって施工した耐火物の耐用性が劣ることや、リバウンドロス、発塵による作業環境の悪化等の問題がある。ノズル内での粉体と水の混合を良くする方法として実開昭58-137465 号や同58-137466 号の開示例がある。両考案は同一出願人のもので、いずれもノズル部での注水が二段階になって、さらに先端部分の注水口の形状及び配置に工夫がなされている。しかし、つまるところノズル内の短距離間での水と粉体のみの混合のため、依然としてその混合状態は不十分である。
【０００５】
半乾式吹付け法は、予めミキサーで必要施工水分量の一部を不定形耐火物の粉体と混練したものを、乾式吹付け機を用いて吹付けノズルまで空気搬送し、ノズルで残りの水又は硬化剤を含んだ溶液あるいは懸濁液を添加して吹付ける施工法である。この施工法の開示例としては、特開昭61-111973 号、及び特公平2-27308 号、同6-17273 号、同5-63437 号、同5-21866 号等がある。これらの施工法では発塵防止、リバウンドロスの減少という点ではある程度の改善が見られるものの、基本的にはノズル部で瞬間的に水又は水溶液と材料を混合しなければならないため、その混合度は良好でなく、水量も変動しやすい。その結果、吹付け材の付着性、施工体の均質性及び充填性が悪い。
【０００６】
湿式吹付け法は、必要施工水分量の全部を事前に不定形耐火物の粉体と混練したものを吹付ける施工法である。この場合ノズルで硬化調整剤や硬化剤を溶かした水溶液が少量添加される場合もある。さらに湿式吹付け法は、材料の搬送手段に応じて、空気搬送法とポンプ搬送法とに区分される。
【０００７】
湿式吹付け法の中でも特に、緻密質流し込み不定形耐火組成物を水又はその他の混練液で混練して流し込み軟度の作業性に調整したものを圧送ポンプで吹付けノズルに搬送し、前記吹付けノズルで圧搾空気とともに保形性付与剤又は凝集剤を水溶液の状態で添加して湿式吹付け施工する方法は、従来の乾式、半乾式又は湿式吹付け施工法と比べて、施工性及び施工体の品質において格段に優れており、このような湿式吹付け施工方法に関して、本出願人は先に幾つかの特許出願をした（特願平8-179913号、特願平8-269399号及び特願平8-293215号）。
【０００８】
施工性に関しては、上記湿式吹付け施工法は、リバウンドロスや発塵が少なく、ノズルマンの技量に依存する水量調節も必要でないため施工が安定しているという利点を有する。また施工体の品質に関しては、施工体の組織が均一かつ緻密であるため、従来吹付け法に比較して耐食性及び強度が格段に優れ、流し込み施工体に比肩できる程である。
【０００９】
しかしながら、上記いずれの湿式吹付け法においても、ミキサーで混練した材料を、空気搬送機もしくは圧送ポンプを用いてノズルまで搬送するため、施工後、ミキサーの清掃、ポンプ、ホース等に残留した材料の清掃、除去作業等が煩雑であり、しかもこれらの材料は使用されずに廃棄しなければならないので不経済である。
【００１０】
【発明が解決しようとする課題】
従って本発明の目的は、従来の乾式吹付け法及び半乾式吹付け法の問題点（リバウンドロスによる環境の悪化、水分増加による施工体品質の劣化等）や、半乾式及び湿式吹付け法の問題点（吹付け工程の煩雑さ、掃除の面倒さ、残材廃棄量が多いことによる不経済性等）を解消し、さらに簡単な装置により流し込み軟度の水分量で高密度、高強度及び高耐食性を有する緻密質不定形耐火物が得られる吹付け施工法を提供することにある。
【００１１】
【課題を解決するための手段】
前記課題を解決するために鋭意研究の結果、本発明者は、不定形耐火組成物の粉体を空気搬送でノズル部まで搬送する途中で施工水分を高圧の圧搾空気を用いて添加すれば、その強力な撹拌作用によって不定形耐火組成物と水との均一混合が短時間で達成できることを発見し、本発明を完成した。
【００１２】
すなわち、本発明の吹付け施工方法は、不定形耐火組成物を吹付け機によって施工する方法であって、空気搬送された不定形耐火組成物に吹付けノズル手前でウォータリングを通して流し込み軟度の作業性が得られる施工水分量と圧搾空気を添加し、さらに吹付けノズル部で凝集剤又は保形性付与剤を添加して吹付け施工することを特徴とする。
【００１３】
また本発明に用いる不定形耐火組成物の主成分は、粒径10mm以下に調整された耐火性骨材70〜98重量％及び粒径10μm 以下の耐火性超微粉２〜30重量％の合計100 重量％からなり、上記主成分に分散剤を外掛けで0.01〜１重量％添加することを特徴とする。
【００１４】
さらに本発明に用いる不定形耐火組成物の主成分は、粒径10mm以下に調整された耐火性骨材62〜97.2重量％、粒径10μm 以下の耐火性超微粉２〜30重量％及びセメント0.8 〜８重量％の合計100 重量％からなり、上記主成分に分散剤を外掛けで0.01〜１重量％添加することを特徴とする。
【００１５】
【発明の実施の形態】
以下に本発明をさらに詳細に説明する。
【００１６】
[1] 水分及び圧搾空気添加方法
本発明の実施形態の一例を図１を参照して具体的に説明する。添加水分10及び圧搾空気９は不定形耐火組成物の空気輸送管８のノズル手前の適正添加位置３から添加する。
【００１７】
(1-A）圧搾空気
添加する圧搾空気９は圧力調整弁４によって調整し、注水口７から添加する水とともにウォータリング１を通して供給する。圧力調整弁４で調整した圧搾空気９の圧力は材料搬送管内圧より高ければ幾らでもよいが、取鍋、タンディッシュ、樋等の通常の施工では２kgf/cm²以上が望ましい。圧搾空気圧力と施工に必要な最適添加水分量との関係を示す図２から明らかなように、２kgf/cm²未満の圧力では施工に必要な最適添加水分量が非常に多く、良好な作業性が得られない。これは、２kgf/cm²未満の圧力では空気搬送された不定形耐火組成物の中心部まで空気及び水分が到達せず、粉体と水との混合が不十分だからである。従って管内中心部まで水分を浸潤させるためには必然的に添加する水分量を増加させる必要があるが、これは施工体の強度低下を招く。
【００１８】
(1-B) 添加水分
添加水分10は注水口７から圧搾空気中９の搬路に添加する。添加水としては、水道水、工業用水及び戻水等、硬化性状に悪影響を及ぼすような有害な物質が混入していない水であればいずれも使用できる。添加水分の圧力は通常の水道水圧程度であれば十分である。水圧が圧搾空気の圧力よりも高ければそのまま添加できるが、圧搾空気より低圧の場合には逆流の危険性があるため、エジェクター６を用いて添加するのが望ましい。
【００１９】
添加水分量は、緻密質不定形耐火物を得るために非常に重要な因子であり、施工体の水分量を少なくして均一に混合するほど緻密性は向上する。不定形耐火組成物粉体は吹付けにより施工されるため、吹付けに必要な流動性が確保されていることも必要である。流し込み軟度の水分量を添加し、ミキサーで十分に混練する湿式吹付け法は、この観点からみれば優れた方法であるが、前記のように掃除の煩雑さ及び廃棄残材が多いという欠点を持つ。本発明は湿式吹付け法程度の水分で施工可能であり、しかも湿式吹付け法の欠点を排除したものである。
【００２０】
添加水分量は、空気搬送された不定形耐火組成物に添加されたときに流し込み軟度の作業性が得られる施工水分量とする。流し込み軟度の作業性が得られる水分量は、使用する不定形耐火組成物の粒度構成及び耐火性骨材の気孔率等によって大きな影響を受ける。本発明における施工水分量は、不定形耐火組成物100 重量％に対して外掛けで4.5 〜9.0 重量％が適当である。添加水分量が4.5 重量％未満では施工材の流動性が不十分で施工ムラが生じ、また9.0 重量％を超えると流落等の吹付け施工性が低下し、施工体の強度が低下する。好ましくは5.0 〜8.5 重量％である。
【００２１】
(1-C）水分及び圧搾空気の添加位置
水分と圧搾空気の混合物は不定形耐火組成物搬送管８に設けた適正添加位置３よりウォーターリング１を介して添加する。適正添加位置３は吹付けノズルの手前１〜５ｍの位置である。水分及び圧搾空気の混合物の添加位置と良好な作業性が得られる添加水分量との関係を示す図３から明らかなように、添加位置が１ｍ未満では不定形耐火組成物と水との混合する時間が不足して低水量では良好な作業性が得られない。１ｍ未満においても良好な作業性を得るためには高水分添加量にする必要があり、施工後の耐火物の強度が低下する。添加位置が１ｍ以上で良好な混合が得られるが、５ｍを超えると作業終了後の搬送管の掃除範囲が増加するため煩雑であり、また廃棄材料が多くなり不経済である。
【００２２】
(1-D）その他
不定形耐火組成物の搬送管８は従来より用いられている金属製、ゴム製又は合成樹脂製等いずれの搬送管でも使用できる。水分及び圧搾空気はウォーターリング１により搬送管８中の不定形耐火組成物粉体中に供給される。水分及び圧搾空気が添加された湿潤体の搬送管はゴム製等のフレキシブル管にする方が取扱いに便利である。凝集剤又は保形性付与剤11の添加はノズル部５に設置されたウォーターリング２にて行う。これらはいずれも水溶液の状態で添加するのが好ましい。
【００２３】
[2] 不定形耐火組成物
本発明にはセメントを含まない不定形耐火組成物及びセメントを含む不定形耐火組成物のいずれも使用することができる。
【００２４】
(2-A）セメントを含まない不定形耐火組成物の場合
セメントを含まない不定形耐火組成物は、主成分として(a）耐火性骨材及び(b）耐火性超微粉を含有し、さらに(c）分散剤を含有する。
【００２５】
(2-A-a）耐火性骨材
本発明に使用する耐火性骨材は、電融アルミナ、焼結アルミナ、ボーキサイト、カイヤナイト、アンダリュサイト、ムライト、シャモット、ロー石、珪石、アルミナ−マグネシアスピネル、マグネシア、ジルコン、ジルコニア、炭化珪素、黒鉛、ピッチ等からなる群から選ばれた少なくとも１種であり、必要に応じて２種以上を併用することができる。耐火性骨材の粒径は10mm以下である。10mm超になると施工時のリバンドロスが多くなる。耐火性骨材の配合量は、耐火性骨材＋耐火性超微粉100 重量％当たり70〜98重量％であるのが好ましく、75〜95重量％であるのがより好ましい。
【００２６】
(2-A-b）耐火性超微粉
耐火性超微粉としてはアルミナ、非晶質シリカ、シリカ、アルミナ、チタニア、ムライト、ジルコニア、クロミア、炭化珪素、カーボン、粘土等の超微粉からなる群から選ばれた少なくとも1 種を使用し、必要に応じて２種以上を併用することができる。耐火性超微粉の粒径は10μm 以下である。粒径が10μm を超えると分散剤との併用による減水効果が小さい。粒径が１μm 以下では減水効果が顕著であるので好ましい。
【００２７】
耐火性超微粉の配合量は耐火性骨材＋耐火性超微粉100 重量％に対して２〜30重量％である。2 重量％未満では減水効果が小さく、また30重量％を超えると施工水量が増加するとともに耐火物施工後に加熱焼成されたときの収縮が大きくなる。好ましい耐火性超微粉の配合量は5 〜25重量％である。
【００２８】
(2-A-c）分散剤
分散剤としてはヘキサメタリン酸ソーダ等の縮合燐酸のアルカリ金属塩及び珪酸のアルカリ金属塩、あるいはカルボン酸、フミン酸、アルキルスルホン酸、芳香族スルホン酸等の有機酸及びそのアルカリ金属塩のうち、１種以上を用いる。分散剤の添加量は不定形耐火組成物100 重量％に対し外掛けで0.01〜１重量％である。分散剤の添加量が0.01重量％未満では耐火性超微粉に対する十分な分散効果が得られず、また１重量％を超えると最適な分散状態が得られない。好ましい分散剤の添加量は0.03〜0.8 重量％である。
【００２９】
(2-A-d）その他の成分
不定形耐火組成物に配合できるその他の成分としては、強度向上のための無機あるいは金属等の繊維、乾燥時の爆裂防止剤としての金属アルミニウム粉末、オキシカルボン酸塩及び有機繊維等がある。さらに金属シリコン、フェロシリコン等の粉末状焼結助剤、炭化ホウ素等の酸化防止剤も使用できる。
【００３０】
[2-B] セメントを含有する不定形耐火組成物の場合
セメントを含有する不定形耐火組成物は、(a）耐火性骨材、(b）耐火性超微粉、及び(c）セメントからなる主成分と、(d）分散剤とを含有する。
【００３１】
(2-B-a）耐火性骨材
本発明に使用する耐火性骨材の種類及び粒径は(2-A-a）に記載したのと同じである。耐火性骨材の配合量は耐火性骨材＋耐火性超微粉＋セメント100 重量％当たり62〜97.2重量％である。また前記と同一の理由により、好ましい耐火性骨材の配合量は69〜94重量％である。
【００３２】
(2-B-b）耐火性超微粉
耐火性超微粉の種類及び粒径は(2-A-b）に記載したのと同じである。耐火性超微粉の配合量は耐火性骨材＋耐火性超微粉＋セメント100 重量％当たり２〜30重量％である。また前記と同一の理由により、好ましい耐火性超微粉の配合量は５〜25重量％である。
【００３３】
(2-B-c）セメント
セメントの配合は施工体の強度向上のために行う。セメントはどのような種類のものでも強度向上のために有益であれば使用可能であるが、耐火性の面からアルミナセメントを使用するのが望ましい。アルミナセメントはJIS １種、２種及び３種クラスが適している。セメントの配合量は耐火性骨材＋耐火性超微粉＋セメント100 重量％当たり0.8 〜８重量％である。0.8 重量％未満では強度向上効果が十分でなく、また８重量％を超えると施工体の耐食性の低下が大きい。好ましくは１〜６重量％である。
【００３４】
(2-B-d）分散剤
分散剤の種類は(2-A-c）に記載したのと同じである。分散剤の添加量は耐火性骨材＋耐火性超微粉＋セメント100 重量％当たり外掛けで0.01〜１重量％である。また前記と同一の理由により、好ましい分散剤の添加量は0.03〜0.8 重量％である。
【００３５】
(2-B-e）その他の成分
不定形耐火組成物に配合できるその他の成分は、(2-A-d）に記載したのと同じであり、強度向上のための無機及び金属等の繊維、爆裂防止剤としての金属アルミニウム粉末、オキシカルボン酸塩及び有機繊維等がある。さらに金属シリコン、フェロシリコン等の粉末状焼結助剤及び炭化ホウ素等の酸化防止剤がある。
【００３６】
[3] 凝集剤及び保形性付与剤
(3-A）凝集剤
凝集剤としては、H ⁺、OH^-イオンあるいはMg²⁺、Ba²⁺、Ca²⁺、Al³⁺、SO₄ ^2-、CO₃ ^2-、Cr₂O ₇ ^2-といった２価又は３価の陽イオン又は陰イオン（耐火性超微粉の表面電荷と反対のもの）を溶出する電解質を使用するのが好ましく、その具体例としては、例えば塩化マグネシウム、塩化カルシウム、塩化バリウム、塩化アルミニウム、硫酸マグネシウム、硫酸アルミニウム、硝酸アルミニウム、硫酸ナトリウム、重クロム酸カリウム、水酸化カルシウム、硫酸、水酸化ナトリウム等がある。
【００３７】
本発明の凝集機構のモデルは、等電凝集（荷電中和型凝集）とSchultz-Hardy 型凝結が該当すると思われる。付言すると、金属酸化物においてはほとんどの場合水素イオン（あるいは水酸化物イオン）が電位決定イオンとなるが、電位決定イオンを少量添加して電気二重層の反発力を消滅させることによって起こる凝集が等電凝集である。また電解質が粒子自身には全く影響（吸着等によって）を与えないで、媒体のイオン強度を高めて粒子の電気二重層を圧縮し、電気的反発力を凝集力より相対的に弱めることによって起こる凝集をSchultz-Hardy 型凝結あるいは単に凝結(Coagulation）という。Schultz-Hardy 型凝結によってできた凝集物は比較的緻密である。
【００３８】
本発明ではこれらの凝集剤を不定形耐火組成物に水分と圧搾空気が添加された湿潤材料に吹込みノズル部で添加する。凝集剤は水溶液の状態で使用するのが好ましい。凝集剤水溶液の添加量は溶液の濃度にもよるが、不定形耐火組成物（耐火性骨材＋耐火性超微粉、又は耐火性骨材＋耐火性超微粉＋セメント）100 重量％に対して、外掛けで0.1 〜1.5 重量％が適当である。凝集剤の添加量が0.1 重量％未満では凝集効果が小さく、1.5 重量％超では施工体の緻密性が低下する。好ましい凝集剤の添加量は0.2 〜1.3 重量％である。凝集剤水溶液の添加は不定形耐火組成物量に同調して作動する定量ポンプで供給するのが好ましい。
【００３９】
また凝集剤水溶液の濃度は20〜50重量％とするのが好ましい。従って、凝集剤の固形分基準の添加量は0.02〜0.75重量％であるのが好ましい。凝集剤の添加量（固形分基準）が0.02重量％未満では凝集効果が小さく、また0.75重量％超では施工体の組織の緻密性が低下（施工体の嵩比重が低下）する。より好ましい凝集剤の添加量（固形分基準）は0.03〜0.5 重量％である。
【００４０】
(3-B）保形性付与剤
本発明では上記凝集剤の代わりに珪酸アルカリ、アルミン酸アルカリ等を保形性付与剤として用いることができる。保形性付与剤は吹付け施工した瞬間に水を含有した不定形耐火組成物の流動性を消失させ、保形性を持たせる作用がある。保形性付与剤としては珪酸アルカリ又はアルミン酸アルカリを用いるのが好ましい。この保形性付与剤は水溶液の状態で添加するのが好ましい。
【００４１】
珪酸アルカリとしては、SiO₂/R₂O（ただしR₂O はアルカリ金属酸化物）のモル比が2.0 〜3.3 であるのが好ましい。アルミン酸アルカリはR₂O/Al₂O₃（ただしR₂O はアルカリ金属酸化物）のモル比が１〜３であるのが好ましい。
【００４２】
保形性付与剤の添加量は施工面温度により影響を受け、施工面温度が高くなるほど多くする必要があるが、不定形耐火組成物100 重量％に対し固形分基準で外掛けで0.1 〜１重量％である。0.1 重量％未満では保形性付与の効果が小さく、また１重量％以上ではアルカリ成分が多くなって耐食性が低下する。好ましい保形性付与剤の添加量は0.15〜0.8 重量％である。
【００４３】
保形性付与剤を水溶液の状態で使用する場合、その濃度は25〜50重量％が適当である。また保形性付与剤水溶液の添加は不定形耐火組成物の量に同調した定量ポンプで供給するのが好ましい。
【００４４】
【実施例】
本発明を以下の実施例及び比較例より具体的に説明するが、本発明はこれらに限定されるものではない。
【００４５】
実施例１〜６、比較例１〜８
本発明の吹付け施工法を従来の乾式施工法、半乾式施工法及び湿式施工法と比較した。使用した不定形耐火組成物の配合は表１に示す通りである。
【００４６】

【００４７】
表１の不定形耐火組成物を使用して本発明の方法及び従来方法により施工した。施工方法、使用した凝集剤及び保形性付与剤の種類及び量、並びに施工後の施工体の特性等を表２に示す。
【００４８】

【００４９】

【００５０】

【００５１】

【００５２】
実施例１〜６は本発明の実施結果であり、施工に必要な水分添加量が少なく施工後の施工体の強度も十分であった。また施工後の残材廃棄量が少なくリバウンドロスも少ない。
【００５３】
これに対して、比較例１は配合３を用いた従来の乾式吹付け法による実験例であるが、粉体と水分との混合状態が悪いため必要水分量が非常に多くなり、施工体の強度が不十分であった。また施工後の残材廃棄量は少ないがリバンドロスが多く不良であった。比較例２及び３は分散剤を含む配合１及び２を用いた実験例である。従来の乾式吹付け法（比較例１）に比べて必要水分量は若干減少するが、依然として混合状態は不良で、水分過多の部分と粉末の部分とが混在するため、保形性付与剤を添加したにもかかわらず施工面で材料が剥がれ落ち、施工不能であった。
【００５４】
比較例４は半乾式吹付け法による実験例であるが、必要水分量がやや多く施工体の強度は十分でない。また施工後の残材廃棄量が非常に多くなった。比較例５は半乾式吹付け法で水分をノズル手前で添加した実験例であるが、水分の混合が十分でないため必要水分量も多くなり施工体の強度が十分でなかった。また残材廃棄量も非常に多い。比較例６及び７は湿式吹付け法による実験例であり、必要水分量が少なく施工体の強度は十分であったが、施工後の残材廃棄量が非常に多かった。
【００５５】
実施例７
配合２の不定形耐火組成物を使用し、圧搾空気圧力を変えた以外実施例６と同じ条件で吹付け施工した。各圧搾空気圧力の時の施工に必要な最適添加水分量を求めた。結果を図２に示す。図２から明らかなように、２kgf/cm²未満の圧力になると施工に必要な最適添加水分量が非常に増大した。
【００５６】
実施例８
配合２の不定形耐火組成物を使用し、図１の装置により水分及び圧搾空気の混合物の添加位置を変えた以外実施例３と同じ条件で吹付け施工した。各水添加位置において施工に必要な最適添加水分量を求めた。結果を図３に示す。図３から明らかなように、添加位置が１ｍ未満になると、施工に必要な最適添加水分量が増大した。
【００５７】
【発明の効果】
以上詳述したように、本発明の吹付け施工法は、従来の粒度構成及び組成を有するセメントを含まない不定形耐火組成物又はセメントを含有する不定形耐火組成物に分散剤を添加した粉体を空気によって搬送し、吹付けノズルの手前でウォータリングを通して流し込み軟度の作業性が得られる水分量を高圧の圧搾空気で添加し、さらにノズル部で保形性付与剤又は凝集剤を添加して施工するものである。本発明の施工法により、リバウンドロスによる環境悪化や水分増加による施工体の品質劣化等の従来の乾式施工法や半乾式吹付け法が有する問題点や、吹込み装置が複雑になるとか、掃除が面倒であるとか、残材廃棄量が多いとかの湿式吹付け法及び半乾式吹付け法が有する問題点が解決され、簡単な工程でしかも環境に優しく経済的で、優れた性状の緻密質不定形耐火物が得られる。
【図面の簡単な説明】
【図１】本発明の吹付け施工法の一例を概略的に示す施工要領図である。
【図２】添加する圧搾空気圧を変化させたときに不定形耐火組成物が施工可能になる流動性を得るための必要添加水分量を示すグラフである。
【図３】水分添加位置と不定形耐火組成物が施工可能になる流動性を得るための必要添加水分量との関係を示すグラフである。
【符号の説明】
１・・・ウォータリング
２・・・ウォーターリング
３・・・水分及び圧搾空気添加孔
４・・・圧搾空気圧力調整弁
５・・・吹付けノズル
６・・・エジェクター
７・・・水分添加孔
８・・・不定形耐火組成物輸送管
９・・・圧搾空気
10・・・水分
11・・・凝集剤又は保形性付与剤
12・・・不定形耐火組成物[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for spraying a dense amorphous refractory used as a lining material for a molten metal container such as a ladle, a tundish, a bowl, and an atmospheric furnace.
[0002]
[Prior art]
In recent years, as the durability of the casting material has improved, the lining material of the molten metal container has shifted from a brick to a casting material that is easy to construct. However, regarding labor saving, the casting method still has a problem that the frame work is complicated. On the other hand, the spraying method does not require a formwork and can be repaired quickly and locally, thus contributing to further labor saving and flexibly responding to the repair plan. Therefore, the spray construction method is increasing.
[0003]
Spraying methods include a dry spraying method, a semi-dry spraying method, and a wet spraying method.
[0004]
The dry spraying method is a method in which powder of an irregular refractory is conveyed to the tip of a spray nozzle with compressed air, and water is added at the nozzle portion for spraying. This method does not require a mixer for kneading, and has advantages such as easy cleaning after use. However, the durability of the refractory material constructed by non-uniform mixing of the powder and water in the nozzle is low. There are problems such as inferiority, rebound loss, and deterioration of work environment due to dust generation. There are disclosed examples of Japanese Utility Model Publication Nos. 58-137465 and 58-137466 as methods for improving the mixing of powder and water in the nozzle. Both devices are of the same applicant, and both have two stages of water injection at the nozzle part, and further devised the shape and arrangement of the water injection port at the tip. However, after all, only the water and powder are mixed within a short distance in the nozzle, so that the mixing state is still insufficient.
[0005]
In the semi-dry spray method, a part of the required construction moisture content is kneaded with the powder of irregular refractory in advance with a mixer, and air-fed to the spray nozzle using a dry spray machine. It is a construction method in which a solution or suspension containing water or a curing agent is added and sprayed. Examples of this construction method are disclosed in JP-A-61-111973, JP-B-2-27308, JP-A-6-1773, JP-A-5-63437, and JP-A-5-21866. Although these construction methods show some improvement in terms of preventing dust generation and reducing rebound loss, basically the water or aqueous solution and material must be mixed instantaneously at the nozzle, so the degree of mixing Is not good, and the amount of water tends to fluctuate. As a result, the adhesion of the spray material, the homogeneity of the construction body and the filling property are poor.
[0006]
The wet spraying method is a spraying method in which all of the required construction moisture amount is previously kneaded with powder of an irregular refractory material. In this case, a small amount of an aqueous solution in which a curing regulator or a curing agent is dissolved may be added by a nozzle. Further, the wet spraying method is classified into an air conveyance method and a pump conveyance method according to the material conveyance means.
[0007]
Among the wet spraying methods, in particular, a dense cast amorphous refractory composition is kneaded with water or other kneading liquid and adjusted to have a soft workability, and is transported to a spray nozzle by a pressure pump, Compared with conventional dry, semi-dry, or wet spraying methods, the wet spraying method by adding a shape-retaining agent or flocculant in the form of an aqueous solution together with compressed air at the attachment nozzle is more workable and constructing. The quality of the body is remarkably excellent, and regarding this wet spraying method, the present applicant has previously filed several patent applications (Japanese Patent Application Nos. 8-179913, 8-269399, and Japanese Patent Application No. 8-269399). Japanese Patent Application No. 8-293215).
[0008]
Regarding the workability, the above-described wet spraying method has the advantage that the rebound loss and dust generation are small, and the water amount adjustment depending on the skill of the nozzle man is not necessary, so that the construction is stable. Regarding the quality of the construction body, the structure of the construction body is uniform and dense, so that the corrosion resistance and strength are much superior to those of the conventional spraying method, which is comparable to the casting construction body.
[0009]
However, in any of the above-described wet spraying methods, the material kneaded by the mixer is transported to the nozzle using an air transporter or a pressure pump, so that after the construction, the material remaining on the mixer cleaning, pump, hose, etc. Cleaning and removal operations are complicated, and these materials are uneconomical because they must be discarded without being used.
[0010]
[Problems to be solved by the invention]
Therefore, the object of the present invention is to solve the problems of the conventional dry spray method and semi-dry spray method (deterioration of environment due to rebound loss, deterioration of construction body quality due to moisture increase, etc.) Eliminate problems (complexity of spraying process, cumbersome cleaning, uneconomical due to large amount of remaining material disposal), and high density and high strength with soft water pouring by simple equipment An object of the present invention is to provide a spraying method for obtaining a dense and irregular refractory having high corrosion resistance.
[0011]
[Means for Solving the Problems]
As a result of earnest research to solve the above problems, the present inventors added the construction moisture using high-pressure compressed air in the middle of conveying the powder of the amorphous refractory composition to the nozzle part by air conveyance, It was discovered that uniform mixing of the amorphous refractory composition and water can be achieved in a short time due to its powerful stirring action, and the present invention has been completed.
[0012]
That is, the spray construction method of the present invention is a method of constructing an amorphous refractory composition by a spraying machine, and is poured into the amorphous refractory composition conveyed by air through watering in front of the spray nozzle and has a softness. It is characterized by adding a construction moisture amount and compressed air that can provide workability, and further adding a flocculant or a shape-retaining agent at the spray nozzle part and performing spraying.
[0013]
The main components of the amorphous refractory composition used in the present invention are a total of 100 to 70 to 98% by weight of a refractory aggregate adjusted to a particle size of 10 mm or less and 2 to 30% by weight of a refractory ultrafine powder having a particle size of 10 μm or less. It is characterized by comprising 0.01% to 1% by weight of a dispersant as an outer coating.
[0014]
Further, the main components of the amorphous refractory composition used in the present invention are 62-97.2% by weight of refractory aggregate adjusted to a particle size of 10 mm or less, 2-30% by weight of refractory ultrafine powder having a particle size of 10 μm or less, and 0.8% cement. It is characterized by comprising a total of 100 wt% of ˜8 wt%, and adding 0.01 to 1 wt% of a dispersant as an outer coating to the main component.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in further detail below.
[0016]
[1] Method of Adding Water and Compressed Air An example of an embodiment of the present invention will be specifically described with reference to FIG. The added moisture 10 and the compressed air 9 are added from the proper addition position 3 before the nozzle of the pneumatic transport pipe 8 of the irregular refractory composition.
[0017]
(1-A) The compressed air 9 to which compressed air is added is adjusted by the pressure regulating valve 4 and supplied through the watering 1 together with the water to be added from the water inlet 7. The pressure of the compressed air 9 adjusted by the pressure adjusting valve 4 may be any pressure as long as it is higher than the pressure in the material conveying pipe, but it is preferably ² kgf / cm ² or more in ordinary construction such as ladle, tundish, firewood. As is clear from Fig. 2, which shows the relationship between the compressed air pressure and the optimum amount of added water necessary for construction, the optimum added amount of moisture necessary for construction is very high at a pressure of less than 2 kgf / cm ² and good workability is achieved. Cannot be obtained. This is because at a pressure of less than 2 kgf / cm ^2, air and moisture do not reach the center of the amorphous refractory composition conveyed by air, and mixing of the powder and water is insufficient. Therefore, it is necessary to increase the amount of water to be added in order to infiltrate the water into the center of the tube, but this causes a decrease in strength of the construction body.
[0018]
(1-B) Added moisture The added moisture 10 is added from the water inlet 7 to the carrying path of the compressed air 9. As the additive water, any water that does not contain harmful substances that adversely affect the curing properties such as tap water, industrial water, and return water can be used. The pressure of the added water is sufficient if it is about the normal tap water pressure. If the water pressure is higher than the pressure of the compressed air, it can be added as it is, but if it is lower than the compressed air, there is a risk of backflow, so it is desirable to add it using the ejector 6.
[0019]
The amount of water added is a very important factor for obtaining a dense amorphous refractory, and the denseness improves as the amount of water in the construction body is reduced and uniformly mixed. Since the amorphous refractory composition powder is applied by spraying, it is also necessary to ensure the fluidity necessary for spraying. The wet spraying method, in which a soft water content is added and the mixture is sufficiently kneaded with a mixer, is an excellent method from this point of view, but has the disadvantages of complicated cleaning and a large amount of waste residue as described above. have. The present invention can be constructed with moisture equivalent to the wet spraying method, and eliminates the disadvantages of the wet spraying method.
[0020]
The amount of added water is the amount of construction water that can be poured into the amorphous refractory composition that is conveyed by air to obtain soft workability. The amount of water that can provide the workability of soft casting is greatly affected by the particle size configuration of the amorphous refractory composition used, the porosity of the refractory aggregate, and the like. The working water amount in the present invention is suitably 4.5 to 9.0% by weight based on 100% by weight of the amorphous refractory composition. If the amount of added water is less than 4.5% by weight, the flowability of the construction material will be insufficient and unevenness of construction will occur, and if it exceeds 9.0% by weight, the spraying workability such as falling will be reduced and the strength of the construction will be reduced. Preferably it is 5.0 to 8.5 weight%.
[0021]
(1-C) Moisture and compressed air addition position The mixture of moisture and compressed air is added through the water ring 1 from the appropriate addition position 3 provided in the amorphous refractory composition transport pipe 8. The proper addition position 3 is a position 1 to 5 m before the spray nozzle. As is apparent from FIG. 3 showing the relationship between the addition position of the mixture of moisture and compressed air and the amount of added moisture at which good workability can be obtained, if the addition position is less than 1 m, the amorphous refractory composition and water are mixed. Good workability cannot be obtained when the amount of water is low due to insufficient time. In order to obtain good workability even at less than 1 m, it is necessary to add a high amount of water, and the strength of the refractory after construction is lowered. Good mixing is obtained when the addition position is 1 m or more. However, if the addition position exceeds 5 m, the cleaning range of the transfer pipe after the operation is increased, which is cumbersome and waste materials increase, which is uneconomical.
[0022]
(1-D) The transport pipe 8 of other irregular refractory composition can be any of conventional transport pipes made of metal, rubber or synthetic resin. Moisture and compressed air are supplied by the water ring 1 into the amorphous refractory composition powder in the transport pipe 8. It is more convenient to handle the transport pipe of the wet body to which moisture and compressed air are added by using a flexible pipe made of rubber or the like. The addition of the flocculant or the shape retention agent 11 is performed by the water ring 2 installed in the nozzle portion 5. These are all preferably added in the form of an aqueous solution.
[0023]
[2] Amorphous refractory composition In the present invention, either an amorphous refractory composition containing no cement or an amorphous refractory composition containing cement can be used.
[0024]
(2-A) Amorphous refractory composition containing no cement Amorphous refractory composition containing no cement contains (a) a refractory aggregate and (b) a refractory ultrafine powder as a main component. (c) Contains a dispersant.
[0025]
(2-Aa) Refractory aggregate The refractory aggregate used in the present invention is fused alumina, sintered alumina, bauxite, kyanite, andalusite, mullite, chamotte, rholite, quartzite, alumina-magnesia spinel. , Magnesia, zircon, zirconia, silicon carbide, graphite, pitch, and the like. At least one selected from the group consisting of pitch, etc. may be used in combination as required. The particle size of the refractory aggregate is 10 mm or less. If it exceeds 10 mm, the reband loss during construction increases. The blending amount of the refractory aggregate is preferably 70 to 98% by weight, more preferably 75 to 95% by weight per 100% by weight of the refractory aggregate and the refractory ultrafine powder.
[0026]
(2-Ab) Fire-resistant ultrafine powder The fire-resistant ultrafine powder is selected from the group consisting of ultrafine powders such as alumina, amorphous silica, silica, alumina, titania, mullite, zirconia, chromia, silicon carbide, carbon, clay, etc. In addition, at least one kind can be used, and two or more kinds can be used in combination as required. The particle size of the refractory ultrafine powder is 10 μm or less. When the particle size exceeds 10 μm, the water reducing effect due to the combined use with the dispersant is small. A particle size of 1 μm or less is preferable because the water reduction effect is remarkable.
[0027]
The blending amount of the refractory ultrafine powder is 2 to 30% by weight with respect to 100% by weight of the refractory aggregate and the refractory ultrafine powder. If it is less than 2% by weight, the water reducing effect is small, and if it exceeds 30% by weight, the amount of construction water increases and the shrinkage when heated and fired after refractory construction is increased. A preferable amount of the fire-resistant ultrafine powder is 5 to 25% by weight.
[0028]
(2-Ac) dispersant As the dispersant, alkali metal salt of condensed phosphoric acid such as sodium hexametaphosphate and alkali metal salt of silicic acid, or organic acid such as carboxylic acid, humic acid, alkyl sulfonic acid, aromatic sulfonic acid and the like One or more alkali metal salts are used. The addition amount of the dispersing agent is 0.01 to 1% by weight as an outer coating with respect to 100% by weight of the amorphous refractory composition. If the added amount of the dispersant is less than 0.01% by weight, a sufficient dispersion effect for the refractory ultrafine powder cannot be obtained, and if it exceeds 1% by weight, an optimum dispersion state cannot be obtained. The amount of the dispersant added is preferably 0.03 to 0.8% by weight.
[0029]
(2-Ad) Other components Other components that can be incorporated into the amorphous fireproof composition include inorganic or metal fibers for improving strength, metallic aluminum powder as an explosion-proofing agent when dried, oxycarboxylate And organic fibers. Furthermore, powdery sintering aids such as metal silicon and ferrosilicon, and antioxidants such as boron carbide can be used.
[0030]
[2-B] Amorphous refractory composition containing cement Amorphous refractory composition containing cement consists of (a) refractory aggregate, (b) refractory ultrafine powder, and (c) cement. A main component and (d) a dispersant.
[0031]
(2-Ba) Refractory aggregate The kind and particle size of the refractory aggregate used in the present invention are the same as described in (2-Aa). The amount of the refractory aggregate is 62-97.2% by weight per 100% by weight of refractory aggregate + refractory ultrafine powder + cement. For the same reason as described above, the preferable amount of the refractory aggregate is 69 to 94% by weight.
[0032]
(2-Bb) Fire-resistant ultrafine powder The type and particle size of the fire-resistant ultrafine powder are the same as described in (2-Ab). The blending amount of the refractory ultrafine powder is 2 to 30% by weight per 100% by weight of the refractory aggregate + refractory ultrafine powder + cement. For the same reason as described above, the preferable amount of the refractory ultrafine powder is 5 to 25% by weight.
[0033]
(2-Bc) Cement cement is added to improve the strength of the construction body. Any kind of cement can be used if it is beneficial for improving the strength, but it is desirable to use alumina cement from the viewpoint of fire resistance. Alumina cement is suitable for

JIS Class

1, 2 and 3 classes. The blending amount of cement is 0.8 to 8% by weight per 100% by weight of refractory aggregate + refractory ultrafine powder + cement. If it is less than 0.8% by weight, the effect of improving the strength is not sufficient, and if it exceeds 8% by weight, the corrosion resistance of the construction body is greatly reduced. Preferably it is 1 to 6% by weight.
[0034]
(2-Bd) Dispersant The type of dispersant is the same as described in (2-Ac). The addition amount of the dispersant is 0.01 to 1% by weight as an outer shell per 100% by weight of the fireproof aggregate + fireproof ultrafine powder + cement. For the same reason as described above, the preferred amount of dispersant added is 0.03 to 0.8% by weight.
[0035]
(2-Be) Other components Other components that can be added to the amorphous fire-resistant composition are the same as those described in (2-Ad), and inorganic and metal fibers and explosion prevention agents for improving strength. Metal aluminum powder, oxycarboxylate, and organic fiber. Further, there are powdery sintering aids such as metal silicon and ferrosilicon and antioxidants such as boron carbide.
[0036]
[3] flocculants and shape retention agents
(3-A) Flocculants Flocculants include H ⁺ , OH ⁻ ions or Mg ²⁺ , Ba ²⁺ , Ca ²⁺ , Al ³⁺ , SO ₄ ²⁻ , CO ₃ ²⁻ , Cr ₂ O ₇ ^{2 It} is preferable to use an electrolyte that elutes a divalent or trivalent cation or anion (opposite to the surface charge of the refractory ultrafine powder), such as magnesium chloride, calcium chloride, There are barium chloride, aluminum chloride, magnesium sulfate, aluminum sulfate, aluminum nitrate, sodium sulfate, potassium dichromate, calcium hydroxide, sulfuric acid, sodium hydroxide and the like.
[0037]
The model of the aggregation mechanism of the present invention is considered to correspond to isoelectric aggregation (charge neutralization type aggregation) and Schultz-Hardy type aggregation. In addition, in most metal oxides, hydrogen ions (or hydroxide ions) are the potential-determining ions, but aggregation occurs by adding a small amount of potential-determining ions to extinguish the repulsive force of the electric double layer. Isoelectric aggregation. In addition, the electrolyte does not affect the particles themselves (by adsorption, etc.), increases the ionic strength of the medium, compresses the electric double layer of the particles, and weakens the electric repulsive force relative to the cohesive force. Agglomeration is called Schultz-Hardy-type condensation or simply coagulation. Aggregates formed by Schultz-Hardy type condensation are relatively dense.
[0038]
In the present invention, these flocculants are added to the wet material in which moisture and compressed air are added to the amorphous refractory composition at the blowing nozzle. The flocculant is preferably used in the form of an aqueous solution. The amount of the flocculant aqueous solution added depends on the concentration of the solution, but is 100% by weight for the amorphous refractory composition (refractory aggregate + refractory ultrafine powder or refractory aggregate + refractory ultrafine powder + cement) The outer cover is suitably 0.1 to 1.5% by weight. When the addition amount of the flocculant is less than 0.1% by weight, the agglomeration effect is small, and when it exceeds 1.5% by weight, the compactness of the construction body decreases. A preferable amount of the flocculant is 0.2 to 1.3% by weight. The aqueous flocculant solution is preferably added by a metering pump that operates in synchronism with the amount of the amorphous refractory composition.
[0039]
The concentration of the flocculant aqueous solution is preferably 20 to 50% by weight. Therefore, the addition amount of the flocculant based on the solid content is preferably 0.02 to 0.75% by weight. When the addition amount (based on solid content) of the flocculant is less than 0.02% by weight, the agglomeration effect is small, and when it exceeds 0.75% by weight, the compactness of the structure of the construction body decreases (the bulk specific gravity of the construction body decreases). A more preferable addition amount (based on solid content) of the flocculant is 0.03 to 0.5% by weight.
[0040]
(3-B) Shape retention property-imparting agent In the present invention, alkali silicate, alkali aluminate, or the like can be used as the shape retention property-imparting agent instead of the aggregating agent. The shape retention property-imparting agent has the effect of eliminating the fluidity of the amorphous refractory composition containing water at the moment of spraying and imparting shape retention properties. As the shape retention agent, alkali silicate or alkali aluminate is preferably used. This shape retaining agent is preferably added in the form of an aqueous solution.
[0041]
As the alkali silicate, the molar ratio of SiO ₂ / R ₂ O (where R ₂ O is an alkali metal oxide) is preferably 2.0 to 3.3. The alkali aluminate preferably has a molar ratio of R ₂ O / Al ₂ O ₃ (where R ₂ O is an alkali metal oxide) of 1 to 3.
[0042]
The amount of the shape-retaining agent added is affected by the construction surface temperature and needs to be increased as the construction surface temperature increases, but it is 0.1 to 1 on the basis of solid content with respect to 100% by weight of the irregular refractory composition. % By weight. If it is less than 0.1% by weight, the effect of imparting shape retention is small, and if it is 1% by weight or more, the alkali component increases and the corrosion resistance decreases. A preferable amount of the shape retention agent is 0.15 to 0.8% by weight.
[0043]
When the shape retention agent is used in the form of an aqueous solution, its concentration is suitably 25 to 50% by weight. Further, it is preferable to add the aqueous shape-retaining agent aqueous solution by a metering pump synchronized with the amount of the amorphous refractory composition.
[0044]
【Example】
The present invention will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited thereto.
[0045]
Examples 1-6, Comparative Examples 1-8
The spray construction method of the present invention was compared with the conventional dry construction method, semi-dry construction method and wet construction method. The composition of the amorphous fireproof composition used is as shown in Table 1.
[0046]

[0047]
Construction was performed by the method of the present invention and the conventional method using the irregular refractory composition shown in Table 1. Table 2 shows the construction method, the types and amounts of the used flocculant and shape retention agent, and the characteristics of the construction body after construction.
[0048]

[0049]

[0050]

[0051]

[0052]
Examples 1 to 6 are the results of implementation of the present invention, and the amount of water added necessary for construction was small, and the strength of the construction body after construction was sufficient. In addition, the amount of residual material discarded after construction is small and rebound loss is also small.
[0053]
On the other hand, Comparative Example 1 is an experimental example by a conventional dry spraying method using Formulation 3, but the required amount of water is very large because the mixing state of the powder and moisture is poor, and the construction body The strength was insufficient. In addition, the amount of waste remaining after construction was small, but there was a lot of reband loss and it was bad. Comparative Examples 2 and 3 are experimental

examples using Formulations

1 and 2 containing a dispersant. The required amount of water is slightly reduced compared to the conventional dry spray method (Comparative Example 1), but the mixed state is still poor and the excessively water-containing part and the powder part are mixed together. Despite the addition, the material peeled off on the construction surface, making it impossible to construct.
[0054]
Although the comparative example 4 is an experimental example by a semi-dry type spraying method, a required amount of water is somewhat large and the strength of the construction body is not sufficient. In addition, the amount of waste material left after construction has increased significantly. Comparative Example 5 is an experimental example in which water was added in front of the nozzle by a semi-dry spraying method, but since the mixing of water was not sufficient, the required amount of water increased and the strength of the construction body was not sufficient. In addition, the amount of discarded material is very large. Comparative Examples 6 and 7 are experimental examples based on the wet spraying method. Although the required amount of water was small and the strength of the construction body was sufficient, the amount of remaining material discarded after construction was very large.
[0055]
Example 7
Spraying was performed under the same conditions as in Example 6 except that the irregular refractory composition of Formula 2 was used and the compressed air pressure was changed. The optimum amount of added water required for construction at each compressed air pressure was determined. The results are shown in FIG. As is apparent from FIG. 2, the optimum added water amount necessary for construction greatly increased when the pressure was less than 2 kgf / cm ² .
[0056]
Example 8
Spraying was performed under the same conditions as in Example 3 except that the amorphous refractory composition of Formula 2 was used and the addition position of the mixture of moisture and compressed air was changed by the apparatus of FIG. The optimum amount of water required for construction was determined at each water addition position. The results are shown in FIG. As apparent from FIG. 3, when the addition position was less than 1 m, the optimum amount of added water necessary for the construction increased.
[0057]
【The invention's effect】
As described above in detail, the spraying method of the present invention is a powder obtained by adding a dispersant to an amorphous refractory composition containing no cement or an amorphous refractory composition containing cement. The body is transported by air, poured through watering in front of the spray nozzle, and added with a water content that gives soft workability with high-pressure compressed air, and then added with a shape-retaining agent or flocculant at the nozzle. And is to be constructed. Due to the construction method of the present invention, there are problems with the conventional dry construction method and semi-dry spraying method such as environmental deterioration due to rebound loss and deterioration of construction body quality due to moisture increase, the blowing device becomes complicated, cleaning The problems of the wet spraying method and semi-dry spraying method, such as the troublesomeness of the waste material and the large amount of remaining material disposal, are solved, and it is simple process, eco-friendly and economical, dense with excellent properties An amorphous refractory is obtained.
[Brief description of the drawings]
FIG. 1 is a construction diagram schematically showing an example of the spray construction method of the present invention.
FIG. 2 is a graph showing the amount of moisture necessary to obtain fluidity that allows the amorphous refractory composition to be applied when the compressed air pressure to be added is changed.
FIG. 3 is a graph showing the relationship between the water addition position and the amount of water added necessary for obtaining fluidity that allows the amorphous refractory composition to be applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Water ring 2 ... Water ring 3 ... Water | moisture content and compressed air addition hole 4 ... Compressed air pressure regulating valve 5 ... Spray nozzle 6 ... Ejector 7 ... Water addition hole 8 ... irregular refractory composition transport pipe 9 ... compressed air
10 ... moisture
11 ... Flocculant or shape retention agent
12 ... Amorphous refractory composition

Claims

A method for applying an amorphous fire-resistant composition containing a fire-resistant aggregate, fire-resistant ultrafine powder and a dispersant, or an amorphous fire-resistant composition containing a fire-resistant aggregate, fire-resistant ultrafine powder, cement and a dispersant by a spraying machine In this case, the water content and the compressed air that give soft workability are added by pouring through the watering before the spray nozzle to the above-mentioned amorphous refractory composition conveyed by air, and the flocculant or the retention agent is further added at the spray nozzle part. A method for spraying dense and irregular shaped refractories , characterized by adding a formability-imparting agent and spraying.

2. The spray construction method according to claim 1, wherein the main component of the irregular refractory composition is 70 to 98% by weight of a refractory aggregate adjusted to a particle size of 10 mm or less, and a refractory ultrafine powder 2 to 2 having a particle size of 10 μm or less. A method for spraying dense amorphous refractories, comprising a total of 100% by weight of 30% by weight, and further adding a dispersing agent to the main component in an amount of 0.01 to 1.0% by weight.

2. The spray construction method according to claim 1, wherein the main component of the irregular refractory composition is 62 to 97.2 wt% of a refractory aggregate adjusted to a particle size of 10 mm or less, and a refractory ultrafine powder 2 to 2 having a particle size of 10 μm or less. A dense amorphous refractory comprising 30% by weight and a total of 100% by weight of 0.8 to 8% by weight of cement, and further adding a dispersant to the main component by 0.01 to 1% by weight . Spray construction method.

In spray construction method according to any one of claims 1 to 3, spraying method of constructing the dense monolithic refractory, characterized in that the addition of alkali silicate or alkali aluminate as said shape retaining property imparting agent.

In spray construction method according to claim 1, spray method of constructing the dense monolithic refractory, characterized in that the pressure of the compressed air 2 kgf / cm @ 2 or more.

In the spray construction method in any one of Claims 1-5, the addition position of the said water | moisture content and the said compressed air shall be 1-5 m before this spray nozzle, The dense amorphous refractory characterized by the above-mentioned . spraying method of constructing.