JP2011032119A - COATING MATERIAL WITH FeO RESISTANCE - Google Patents
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本発明は、製銑、製鋼、圧延工程等で使用される加熱炉、均熱炉、熱処理炉、炉蓋、カバー等に施工されたセラミックファイバーブロックやスキッドポスト用セラミックファイバー成形体などのセラミックファイバー断熱材の表面に塗布される耐ＦｅＯ性コーティング材に関する。 The present invention relates to ceramic fibers such as ceramic fiber blocks and ceramic fiber moldings for skid posts installed in heating furnaces, soaking furnaces, heat treatment furnaces, furnace lids, covers, etc. used in iron making, steel making, rolling processes, etc. The present invention relates to a FeO-resistant coating material applied to the surface of a heat insulating material.
近年、加熱炉等の各種窯炉設備の省エネや、断熱を目的にセラミックファイバーが使用されている。セラミックファイバーは熱伝導率が低いのみならず、軽量かつ低嵩比重であるため、熱慣性に優れ、炉の降温、昇温時間が短くてすむ等の利点があり、セラミックファイバーブランケットの圧縮積層材や、セラミックファイバーブランケットを折り畳んで取付け金具と一体化したセラミックファイバーブロックが、溶融金属と接触しない部位で、主なライニングとして採用されている。また、スキッドポスト用断熱材としてセラミックファイバー成形体が使用されている。 In recent years, ceramic fibers have been used for the purpose of energy saving and heat insulation of various kiln facilities such as a heating furnace. Ceramic fiber not only has low thermal conductivity, but also has a light weight and low bulk specific gravity. Therefore, it has advantages such as excellent thermal inertia, lowering furnace temperature, and shorter heating time. In addition, a ceramic fiber block in which a ceramic fiber blanket is folded and integrated with a mounting bracket is used as a main lining at a portion that does not come into contact with molten metal. Moreover, the ceramic fiber molded object is used as a heat insulating material for skid posts.
しかし、これらのようなセラミックファイバーからなる断熱材は、前記のような優れた特性を有しているものの、鋼片が加熱された場合に生成するＦｅＯに対する侵食抵抗性に劣り、低融点物質のファイヤライト等の生成により、溶融、収縮・焼結が促進されて断熱厚みが減少したり、目地開きを生じ、断熱性が低下するという問題がある。 However, although these heat insulating materials made of ceramic fibers have the excellent characteristics as described above, they are inferior in erosion resistance to FeO produced when a steel slab is heated, and are low melting point materials. There is a problem that the generation of firelite or the like promotes melting, shrinkage, and sintering, thereby reducing the heat insulation thickness or causing joint opening, resulting in a decrease in heat insulation.
このような問題を解決するために、セラミックファイバー断熱材の表面にスプレーガン等により施工するコーティング材が使用されている。例えば、特許文献１には、アルミナを含む耐火骨材粉末と、結晶形態がα−石英型であるシリカ粉末と、硼酸と、可塑剤含有合成樹脂エマルジョンとを、所定の割合で含んだセラミックファイバー用のコーティング材が開示されている。このコーティング材中には、主要骨材としてアルミナ（７０％以上）、アルミナ以外の骨材（０〜３０％）としてスピネル、マグネシア、シリカ、炭化珪素、窒化ケイ素など通常耐火物に使用される耐火物質が使用されている。また、特許文献２には、セラミックファイバーの表面にセラミックファイバー含有吹付け材を吹付け、その施工面に更にアルミナを含むコーティング材を塗布する方法が開示されている。更には、特許文献３には、結晶質ファイバー、無機バインダー、有機バインダー及びアルミナ粉を必須成分として含有し、結晶質ファイバーとアルミナ粉の合計が全焼成分の９０質量％以上となるようにした、加熱炉の耐スケール性コーティング材が開示されている。 In order to solve such a problem, a coating material applied on the surface of the ceramic fiber heat insulating material by a spray gun or the like is used. For example, Patent Document 1 discloses a ceramic fiber containing a refractory aggregate powder containing alumina, silica powder having an α-quartz crystal form, boric acid, and a plasticizer-containing synthetic resin emulsion in a predetermined ratio. A coating material is disclosed. In this coating material, the main aggregate is alumina (70% or more), the aggregate other than alumina (0 to 30%) is spinel, magnesia, silica, silicon carbide, silicon nitride, and other refractories usually used for refractories. Substance is being used. Patent Document 2 discloses a method in which a ceramic fiber-containing spray material is sprayed on the surface of a ceramic fiber, and a coating material containing alumina is further applied to the construction surface. Furthermore, Patent Document 3 contains a crystalline fiber, an inorganic binder, an organic binder, and alumina powder as essential components, so that the total of the crystalline fiber and the alumina powder is 90% by mass or more for the total firing. A scale-resistant coating material for a heating furnace is disclosed.
しかしながら、操業が過酷になるにつれて、鋼片より発生するＦｅＯ量が増大し、また、操業温度が上昇すると、アルミナやアルミナ−SiO2を主体とするコーティング材では耐ＦｅＯ性が不十分である。また、上述したような従来のコーティング材では、熱間で液相が生じ易く、使用中にセラミックファイバー断熱材の表面に施工されたコーティング材が収縮し、亀裂、剥離が生じ、それによりセラミックファイバー断熱材がＦｅＯに侵食され、断熱材厚みの減少と目地開きによる断熱性低下等のトラブルが多発する問題がある。更には、従来のコ−ティング材では、冷間に冷やす際に残存収縮が大きいことから、冷却時にセラミックファイバー断熱材から剥離することがあり、耐用性にも課題があった。更にまた、従来使用されているコ−ティング材の嵩比重は１．５以上であり、セラミックファイバーの標準嵩比重０．１３に比べてはるかに大きく、施工に、多量の使用量が必要であることから、軽量断熱性にも劣り、施工厚みが厚くなると自重により剥離しやすい課題があった。 However, as the operation becomes severe, the amount of FeO generated from the steel slab increases, and when the operation temperature rises, the coating material mainly composed of alumina or alumina-SiO 2 has insufficient FeO resistance. In addition, in the conventional coating material as described above, a liquid phase is likely to be generated between the heat, and the coating material applied to the surface of the ceramic fiber heat-insulating material shrinks during use, causing cracks and peeling, thereby causing the ceramic fiber. There is a problem that the heat insulating material is eroded by FeO, and troubles such as a decrease in the heat insulating material thickness and a decrease in heat insulating property due to joint opening occur frequently. Furthermore, since the conventional coating material has a large residual shrinkage when cooled in the cold, it may be peeled off from the ceramic fiber heat insulating material during cooling, and there is a problem in durability. Furthermore, the bulk specific gravity of the conventionally used coating material is 1.5 or more, which is much larger than the standard bulk specific gravity 0.13 of ceramic fiber, and a large amount of use is required for construction. For this reason, there is a problem in that it is inferior in lightweight heat insulation and easily peels off due to its own weight when the construction thickness is increased.
本発明では、加熱炉などに施工されるセラミックファイバー断熱材のＦｅＯによる侵食を防止するために、その表面にコーティングするコ−ティング材の耐ＦｅＯ性、熱間収縮の抑制、及び残存収縮の抑制を図り、耐ＦｅＯ性に優れると共に、耐亀裂性、耐剥離性等に優れ、かつ施工量を抑制できる軽量断熱質のコーティング材を提供する。 In the present invention, in order to prevent erosion of the ceramic fiber heat insulating material applied to a heating furnace or the like by FeO, the coating material coated on the surface has FeO resistance, suppression of hot shrinkage, and suppression of residual shrinkage. Thus, a lightweight heat insulating coating material that is excellent in FeO resistance, crack resistance, peel resistance, and the like and that can suppress the amount of construction is provided.
本発明者らは、耐ＦｅＯ性に優れる軽量断熱質のカルシウム−アルミナ原料であるCaO・6Al2O3（以下、「CA6原料」と称す）に着目して、上記課題を解決できるコーティング材について鋭意、研究・開発を行った結果、ＣＡ６原料はＦｅＯと反応しにくい性質を持ち、アルミナ又はスピネルと併用することで、更にＣＡ６が生成すると共に、アルミナリッチの二次スピネルが生成し、二次スピネルの膨張により高温での収縮が抑制され、耐亀裂・剥離性が格段に向上することを見出し、本発明を完成した。 The present inventors pay attention to CaO.6Al 2 O 3 (hereinafter referred to as “CA6 raw material”), which is a lightweight heat insulating calcium-alumina raw material excellent in FeO resistance, and a coating material that can solve the above-mentioned problems. As a result of diligent research and development, the CA6 raw material has the property of not easily reacting with FeO, and when used in combination with alumina or spinel, CA6 is further generated, and alumina-rich secondary spinel is generated. The present inventors completed the present invention by finding that shrinkage at a high temperature is suppressed by the expansion of the spinel and the crack resistance and peelability are remarkably improved.
すなわち、本発明は、耐火性のセラミックファイバー断熱材の表面に塗布される耐ＦｅＯ性コーティング材であって、骨材として、粒径が１ｍｍ以下、嵩比重が０．６〜０．８、気孔径が５μｍ以下、及び見掛気孔率が６０体積％以上のカルシウム−アルミナ原料を５０〜８０質量％含有し、更に、結晶質ファイバーを５〜４０質量％、及びコロイダルシリカを５〜３０質量％含有することを特徴とする耐ＦｅＯ性コーティング材である。 That is, the present invention is a FeO-resistant coating material applied to the surface of a fire-resistant ceramic fiber heat insulating material, and as an aggregate, the particle size is 1 mm or less, the bulk specific gravity is 0.6 to 0.8, 50 to 80% by mass of a calcium-alumina raw material having a pore size of 5 μm or less and an apparent porosity of 60% by volume or more, 5 to 40% by mass of crystalline fiber, and 5 to 30% by mass of colloidal silica It is a FeO resistant coating material characterized by containing.
また、本発明は、耐火性のセラミックファイバー断熱材の表面に塗布される耐ＦｅＯ性コーティング材であって、骨材として、粒径が１ｍｍ以下、嵩比重が０．６〜０．８、気孔径が５μｍ以下、及び見掛気孔率が６０体積％以上のカルシウム−アルミナ原料を２０〜６０質量％、粒径１ｍｍ以下のアルミナまたは粒径１ｍｍ以下のスピネルのいずれか１種もしくは２種からなる原料が５〜５０質量％、結晶質ファイバーを５〜４０質量％、及びコロイダルシリカを５〜３０質量％含有することを特徴とする耐ＦｅＯ性コーティング材である。 The present invention is also a FeO-resistant coating material applied to the surface of a fire-resistant ceramic fiber heat insulating material. The aggregate has a particle size of 1 mm or less, a bulk specific gravity of 0.6 to 0.8, 20-60% by mass of calcium-alumina raw material having a pore size of 5 μm or less and an apparent porosity of 60% by volume or more, consisting of either one or two of alumina having a particle size of 1 mm or less or spinel having a particle size of 1 mm or less. The FeO-resistant coating material is characterized in that the raw material contains 5 to 50% by mass, the crystalline fiber 5 to 40% by mass, and the colloidal silica 5 to 30% by mass.
耐ＦｅＯ性に優れるカルシウム−アルミナ原料を用いて、更にはこれにアルミナ又はスピネル原料をうまく活用することで、ＣＡ６及びアルミナリッチの二次スピネルが生成し、その膨張により高温での収縮が抑制され耐亀裂性が格段に向上し、耐ＦｅＯ性と耐亀裂・剥離性に優れる耐ＦｅＯ性軽量断熱質コーティング材を得ることができる。また、本発明ではコーティング材の嵩比重が小さいため、施工量を削減でき、厚く施工した場合でも、自重による施工体の落下を抑制できる。更にコーティング材自体の気孔率が大きいため、熱伝導率が低く、炉壁を通しての放散熱が少なくなり、セラミックファイバーブロック等の寿命延長、安定操業が可能となる。 By using calcium-alumina raw material with excellent FeO resistance, and by making good use of alumina or spinel raw material for this, CA6 and alumina-rich secondary spinel are generated, and the expansion is suppressed by the expansion. It is possible to obtain a FeO-resistant lightweight heat insulating coating material that has markedly improved crack resistance and is excellent in FeO resistance and crack resistance / peelability. Moreover, since the bulk specific gravity of a coating material is small in this invention, a construction amount can be reduced and even when it constructs thickly, the fall of the construction body by dead weight can be suppressed. Furthermore, since the porosity of the coating material itself is large, the thermal conductivity is low, the heat dissipated through the furnace wall is reduced, and the life of the ceramic fiber block and the like can be extended and stable operation can be achieved.
本発明における被コーティング材料のセラミックファイバーは、アルミナ(Al2O3)とシリカ(SiO2)を主成分とした人造無機繊維のことであり、アルミナ成分の含有量等により、耐熱性が異なる。アルミナ含有量が70％以上の結晶質繊維はアルミナファイバー（ムライトファイバーを含む）とも言い、特に耐熱性が高い。本発明に係るコーティング材は、これらアルミナとシリカを主成分とすることで共通するいずれのセラミックファイバーに対しても適用可能である。
以下に、好適な実施形態を挙げて本発明の耐ＦｅＯ性コーティング材を更に説明する。
The ceramic fiber of the material to be coated in the present invention is an artificial inorganic fiber mainly composed of alumina (Al 2 O 3 ) and silica (SiO 2 ), and has different heat resistance depending on the content of the alumina component. Crystalline fibers having an alumina content of 70% or more are also referred to as alumina fibers (including mullite fibers), and have particularly high heat resistance. The coating material according to the present invention can be applied to any of the common ceramic fibers by using these alumina and silica as main components.
The FeO-resistant coating material of the present invention will be further described below with reference to preferred embodiments.
本発明の耐ＦｅＯ性コーティング材では、CaO・6Al2O3（ＣＡ６）原料が有する耐ＦｅＯ性を活用し、かつ耐亀裂・剥離性に優れるコーティング層を形成するために、粒径１ｍｍ以下のＣＡ６原料を含有する。ＣＡ６原料は多孔質、高耐火性であり、製銑、製鋼、圧延工程等で使用される加熱炉等の実使用温度（1400℃）までなら、膨張し、残存の収縮が少ない。ＣＡ６原料はその耐火性からＣａＯが１０％未満のものを使用するのが好ましい。ＣａＯが１０％以上のCaO・Al2O3（ＣＡ）やCaO・2Al2O3（ＣＡ２）は耐火性が劣り、嵩比重も大きい。ＣＡ６の粒径は耐ＦｅＯ性等には直接影響しないが、吹付け作業性等を考慮して、１ｍｍ以下のものを用いるようにする。1ｍｍを超える粒径のＣＡ６は、後述するアルミナやスピネルとの反応性に劣り、二次的に生成するＣＡ６やスピネルが形成され難い。なお、骨材の粒径は、いずれもレーザー回折・散乱式測定法による粒径を指す。また、ＣａＯが６〜８％で粒径が１ｍｍ以下のＣＡ６であれば、嵩比重０．６〜０．８、気孔径５μｍ以下、及び見掛気孔率６０体積％以上を満たすものが殆どである。 In the FeO resistant coating material of the present invention, in order to utilize the FeO resistance possessed by the CaO · 6Al 2 O 3 (CA6) raw material and to form a coating layer having excellent crack resistance and peelability, the particle size is 1 mm or less. Contains CA6 raw material. The CA6 raw material is porous and has high fire resistance, and expands up to the actual use temperature (1400 ° C.) of heating furnaces used in iron making, steel making, rolling processes, etc., and there is little residual shrinkage. It is preferable to use a CA6 material having a CaO content of less than 10% because of its fire resistance. CaO · Al 2 O 3 (CA) and CaO · 2Al 2 O 3 (CA2) with CaO of 10% or more have poor fire resistance and large bulk specific gravity. The particle size of CA6 does not directly affect the FeO resistance and the like, but in consideration of the spraying workability etc., the one having a diameter of 1 mm or less is used. CA6 having a particle diameter exceeding 1 mm is inferior in reactivity with alumina and spinel, which will be described later, and it is difficult to form CA6 and spinel generated secondarily. The particle size of the aggregate refers to the particle size obtained by the laser diffraction / scattering measurement method. Further, if CAO is 6 to 8% and the particle size is CA6 of 1 mm or less, most of them satisfy a bulk specific gravity of 0.6 to 0.8, a pore diameter of 5 μm or less, and an apparent porosity of 60 volume% or more. is there.
本発明は、ＣＡ６原料の耐ＦｅＯ性等の特性を活かしつつ、軽量性及び断熱性を兼ね備えたコーティング材であるが、その組成によって２つの態様が可能である。先ず、第一の態様は、上記のようなＣＡ６原料を５０〜８０質量％、好ましくは６０〜７５質量％含有し、結晶質ファイバーを５〜４０質量％、好ましくは７〜２５質量％含有し、コロイダルシリカを５〜３０質量％、好ましくは１０〜２５質量％含有したコーティング材である。 The present invention is a coating material that combines the light weight and heat insulation properties while utilizing the characteristics such as FeO resistance of the CA6 raw material, but two modes are possible depending on the composition. First, a 1st aspect contains 50-80 mass% of the above CA6 raw materials, Preferably it contains 60-75 mass%, 5-40 mass%, Preferably it contains 7-25 mass% of crystalline fiber. The coating material contains 5 to 30% by mass, preferably 10 to 25% by mass of colloidal silica.
結晶質ファイバーは、養生、乾燥時の亀裂発生を抑制し、コーティング材が使用されるセラミックファイバー断熱材の表面との結合力を高めるためのものであり、好ましくは、アルミナ系またはアルミナ分が７２％質量以上のムライト系結晶質ファイバーを使用するのがよい。結晶質ファイバーの濃度が５質量％より少ないと結合力を高める効果が望めず、反対に４０質量％より多くなると、結晶質ファイバーがコーティング材に均一に分散しにくくなる。又、コロイダルシリカとＣＡ６原料は反応し、ＣａＯ−ＳｉＯ2−Ａｌ2Ｏ3系の化合物を生成する。この時わずかに膨張するが耐火性は低下する。一方、コロイダルシリカの濃度について、５質量％より少ないと接着性が低下し、３０質量％より多いと耐熱性が低下する。軽量性の面からは、コロイダルシリカは少ない方が好ましく、結晶質ファイバーは多い方が好ましい。 The crystalline fiber is for suppressing cracking during curing and drying, and for increasing the bonding strength with the surface of the ceramic fiber heat insulating material used for the coating material. Preferably, the alumina fiber or alumina content is 72. It is preferable to use a mullite crystalline fiber having a mass of at least%. If the concentration of the crystalline fiber is less than 5% by mass, the effect of increasing the bonding force cannot be expected. Conversely, if the concentration is more than 40% by mass, the crystalline fiber is difficult to uniformly disperse in the coating material. Also, the colloidal silica and the CA6 raw material react to produce a CaO—SiO 2 —Al 2 O 3 based compound. Although it expands slightly at this time, fire resistance falls. On the other hand, when the concentration of colloidal silica is less than 5% by mass, the adhesiveness is lowered, and when it is more than 30% by mass, the heat resistance is lowered. From the viewpoint of light weight, it is preferable that the amount of colloidal silica is small, and it is preferable that the amount of crystalline fiber is large.
次に、第二の態様は、上記第一の態様におけるＣＡ６原料の一部を、粒径１ｍｍ以下のアルミナまたはスピネルのいずれか１種もしくは２種からなる原料で置換したものである。すなわち、上述したＣＡ６原料を２０〜６０質量％、好ましくは２０〜５０質量％含有し、結晶質ファイバーを５〜４０質量％、好ましくは７〜２５質量％含有し、コロイダルシリカを５〜３０質量％、好ましくは１０〜２５質量％含有し、粒径１ｍｍ以下のアルミナまたは粒径１ｍｍ以下のスピネルのいずれか１種もしくは２種からなる原料を５〜５０質量％、好ましくは２０〜４７質量％含有するコーティング材である。 Next, in the second aspect, a part of the CA6 raw material in the first aspect is replaced with a raw material composed of one or two of alumina and spinel having a particle diameter of 1 mm or less. That is, it contains 20 to 60% by mass, preferably 20 to 50% by mass of the above-mentioned CA6 raw material, 5 to 40% by mass, preferably 7 to 25% by mass of crystalline fiber, and 5 to 30% by mass of colloidal silica. %, Preferably 10 to 25% by mass, and 5 to 50% by mass, preferably 20 to 47% by mass of one or two raw materials of alumina having a particle size of 1 mm or less or spinel having a particle size of 1 mm or less It is a coating material to be contained.
上記のとおり、ＣＡ６原料を２０〜６０質量％とし、粒径１ｍｍ以下のアルミナまたは粒径１ｍｍ以下のスピネルのいずれか一方又は両方を５〜５０質量％（２種の場合はそれらの合計）と組み合わせても使用できる。ＣＡ６原料とアルミナを組み合わせた場合、コロイダルシリカと粒径１ｍｍ以下のＣＡ６原料が反応してＣａＯ−ＳｉＯ2−Ａｌ2Ｏ3系の化合物が生成すると共に、更に、新たなＣＡ６が生成し、また、ＣＡ６原料とスピネルを組み合わせた場合、更に、アルミナリッチな二次スピネルが生成する。更には、ＣＡ６原料、アルミナ、及びスピネルの３つを組み合わせた場合、新たなＣＡ６とアルミナリッチな二次スピネルが生成する。これらの新たなＣＡ６や二次スピネルの生成により原料は膨張し、その膨張により収縮が抑制され、亀裂が防止され、また、熱間での収縮が抑制されることで、常温に戻した際の残存収縮も小さくなる。 As described above, the CA6 raw material is 20 to 60% by mass, and either one or both of alumina having a particle size of 1 mm or less and spinel having a particle size of 1 mm or less is 5 to 50% by mass (in the case of two types, the total thereof) Can be used in combination. When the CA6 raw material and alumina are combined, the colloidal silica and the CA6 raw material having a particle size of 1 mm or less react to produce a CaO—SiO 2 —Al 2 O 3 -based compound, and further, new CA6 is produced. When the CA6 raw material and spinel are combined, an alumina-rich secondary spinel is further generated. Further, when three of the CA6 raw material, alumina, and spinel are combined, new CA6 and alumina-rich secondary spinel are generated. The raw material expands due to the generation of these new CA6 and secondary spinel, the shrinkage is suppressed by the expansion, cracks are prevented, and the shrinkage in the hot state is suppressed. Residual shrinkage is also reduced.
ＣＡ６、スピネル、及びアルミナの粒径が上記粒径より大きい場合は、ＣＡ６や二次スピネルが生成しにくくなり、収縮が抑制できず、亀裂が発生しやすくなる。また、スピネル又はアルミナの濃度が上記濃度範囲の下限を下回る場合には、これらとＣＡ６とを併用する効果は少なくなり、反対に上限を超える場合には、軽量、断熱性が劣る。この第二の態様では、ＣＡ６をベースにして、アルミナ又はスピネルのいずれか１種もしくは２種を組み合わせて使用することができるが、好適にはＣＡ６、アルミナ、及びスピネルの３種を用いた場合が最も効果的である。 When the particle diameters of CA6, spinel, and alumina are larger than the above particle diameter, CA6 and secondary spinel are difficult to generate, shrinkage cannot be suppressed, and cracks are likely to occur. Moreover, when the density | concentration of a spinel or an alumina is less than the minimum of the said density | concentration range, the effect which uses these and CA6 together decreases, and when it exceeds an upper limit on the contrary, light weight and heat insulation are inferior. In this second aspect, based on CA6, any one or two of alumina or spinel can be used in combination, but preferably three types of CA6, alumina and spinel are used. Is the most effective.
第二の形態で使用するアルミナは、熱安定性の高いα−アルミナを使用するのが好ましい。一方、スピネルは、各種のアルミナ・マグネシウムスピネルが使用され、理論組成スピネル、理論組成スピネルよりアルミナの多いアルミナリッチスピネル、理論組成スピネルよりマグネシアの多いマグネシアリッチスピネルなどがある。第二の形態で使用するスピネルはＭｇＯ含有量が５質量％〜３５質量％のものが好ましい。ＭｇＯの含有量が５質量％未満だとアルミナの組成に近づき、二次スピネルが生成しづらくなる。反対に３５質量％を超えると、後述するように添加する水との反応で、水和が起こり、消化による亀裂が入り易くなる。なお、結晶質ファイバー及びコロイダルシリカについては、第一の態様の場合と同様である。また、スピネルの代わりにＭｇＯを少量使用することも可能であるが、前述の水和問題や熱間でのスピネル生成に伴う急激な膨張で、セラミックファイバー断熱材との膨張差による剥離が生じ易くなるので、使用の際には注意が必要である。具体的には耐消化性に優れるＭｇＯを使用する必要がある。 As the alumina used in the second form, α-alumina having high thermal stability is preferably used. On the other hand, as the spinel, various types of alumina / magnesium spinels are used, and there are a theoretical composition spinel, an alumina rich spinel having more alumina than the theoretical composition spinel, and a magnesia rich spinel having more magnesia than the theoretical composition spinel. The spinel used in the second embodiment preferably has an MgO content of 5% by mass to 35% by mass. If the content of MgO is less than 5% by mass, the composition of alumina approaches and secondary spinel is difficult to be generated. On the other hand, when it exceeds 35% by mass, hydration occurs due to the reaction with water added as described later, and cracks due to digestion easily occur. In addition, about crystalline fiber and colloidal silica, it is the same as that of the case of a 1st aspect. It is also possible to use a small amount of MgO instead of spinel, but due to the rapid expansion associated with the above-mentioned hydration problem and hot spinel formation, peeling due to a difference in expansion from the ceramic fiber heat insulating material is likely to occur. Therefore, care must be taken when using it. Specifically, it is necessary to use MgO which is excellent in digestion resistance.
本発明の耐ＦｅＯ性コーティング材をセラミックファイバー断熱材に塗布する方法については特に制限はないが、一般には、スプレーガン等によりセラミックファイバー断熱材に施工する方法が採用される。この際、本発明の耐ＦｅＯ性コーティング材に水を加えて通常８０００〜２００００cＰ程度の粘度にして、施工厚みが０．５〜１０ｍｍ程度となるように、スプレーガン等によりセラミックファイバー断熱材に施工するのが好ましい。施工厚みがこれより薄い場合には耐ＦｅＯ性コーティング材の効果が十分ではなく、反対にこれより厚い場合には、自重に耐えられずに落下するおそれがある。この際の水添加量（外掛け）については、多孔質のＣＡ６原料を使用するため、一般には４０〜８０質量％であるのがよい。このため、ＣＡ６原料を使わない従来のコ−ティング材では施工材料の嵩比重が１．７程度であるのに対し、本発明のコーティング材では０．８〜１．４であり、施工量が従来の２０％から５０％削減できる。この嵩比重はＣＡ６の使用比率に応じて決まり、軽量、断熱性が確保できる。 Although there is no restriction | limiting in particular about the method of apply | coating the FeO-resistant coating material of this invention to a ceramic fiber heat insulating material, Generally, the method of applying to a ceramic fiber heat insulating material with a spray gun etc. is employ | adopted. At this time, water is added to the FeO-resistant coating material of the present invention so that the viscosity is usually about 8000 to 20000 cP, and the construction thickness is about 0.5 to 10 mm. It is preferable to do this. When the construction thickness is thinner than this, the effect of the FeO-resistant coating material is not sufficient. On the other hand, when the construction thickness is thicker than this, there is a risk that it will fall without being able to withstand its own weight. The amount of water added (outer coating) at this time is generally 40 to 80% by mass because a porous CA6 raw material is used. For this reason, in the conventional coating material which does not use CA6 raw material, the bulk specific gravity of the construction material is about 1.7, whereas in the coating material of the present invention, the construction amount is 0.8 to 1.4. 50% can be reduced from the conventional 20%. This bulk specific gravity is determined according to the use ratio of CA6, and light weight and heat insulation can be secured.
また、本発明の耐ＦｅＯ性軽量コーティング材には、必要により上記成分のほか、吹付けまたは塗布時ダレを防止し、接着性を向上させるために、有機バインダーのＣＭＣ（カルボキシメチルセルロース）やＰＶＡ（ポリビニルアルコール）等を配合したり、ベントナイト等の耐火材を配合したり、界面活性剤などの微量調整剤を配合して保存安定性などを向上させたりすることができる。しかし、これらの追加成分は耐ＦｅＯ性を損なわないように、耐ＦｅＯ性軽量セラミックファイバーコーティング材の８質量％以下とすることが望ましい。 In addition to the above components, the FeO-resistant lightweight coating material of the present invention, if necessary, prevents dripping during spraying or application, and improves the adhesion by organic binders such as CMC (carboxymethylcellulose) and PVA ( Polyvinyl alcohol) and the like, refractory materials such as bentonite and the like, and a minute amount adjusting agent such as a surfactant can be added to improve the storage stability. However, these additional components are desirably 8% by mass or less of the FeO-resistant lightweight ceramic fiber coating material so as not to impair the FeO resistance.
［実施例１〜１０、比較例１〜６］
以下の表１に記載する骨材を用いて、表２に示す材料及び配合にて実施例１〜１０及び比較例１〜６に係るコーティング材を調製した。また、実施例及び比較例で得られたコーティング材の諸特性を表２に併記した。
[Examples 1 to 10, Comparative Examples 1 to 6]
Using the aggregates shown in Table 1 below, coating materials according to Examples 1 to 10 and Comparative Examples 1 to 6 were prepared using the materials and blends shown in Table 2. In addition, Table 2 shows various properties of the coating materials obtained in Examples and Comparative Examples.
上記調製においては、各コーティング材を水で混練後、鋳込み枠に流し込み、室温にて２４時間養生して試験用コーティングサンプル（100mm×100mm×厚み10mm）を作製し、その表面に発生した亀裂の有無を目視にて確認した。また、試験用コーティングサンプルを１４００℃で３時間焼成して、その表面に発生した亀裂の有無を観察した。更に、耐ＦｅＯ性評価として、試験用コーティングサンプルに２５mmφの円盤状のＦｅＯを置き、その状態のまま１４００℃で３時間焼成して、ＦｅＯとの反応によって形成された反応変色径を測定した。そして、比較例１でＦｅＯと反応して円形に広がった長さの２点の平均長さを１００とし、各サンプルの反応変色径の平均長さを反応変色比として表示した。更にまた、試験用コーティングサンプル（20mm×20mm×長さ70mm）を用いて１４００℃までの熱膨張試験を行い、常温まで冷却した時の残存線変化を測定した（昇温速度及び冷却速度はいずれも４℃/min）。残存線変化率は、焼成前のサンプル長さを基準にして、１４００℃に加熱して常温までサンプルを冷やした後のサンプル長さから収縮した割合（収縮量）を求めた。結果を表２に示す。なお、実施例１と比較例１、２の場合については熱膨張試験による熱膨張率の変化をそれぞれ図１〜３に示す。 In the above preparation, each coating material is kneaded with water, poured into a casting frame, and cured at room temperature for 24 hours to prepare a test coating sample (100 mm × 100 mm × thickness 10 mm). The presence or absence was confirmed visually. Moreover, the test coating sample was baked at 1400 ° C. for 3 hours, and the presence or absence of a crack generated on the surface was observed. Further, as an evaluation of FeO resistance, a disc-shaped FeO of 25 mmφ was placed on a test coating sample and fired at 1400 ° C. for 3 hours in that state, and a reaction discoloration diameter formed by reaction with FeO was measured. Then, in Comparative Example 1, the average length of the two points that reacted with FeO and spread in a circular shape was defined as 100, and the average length of the reaction discoloration diameter of each sample was displayed as the reaction discoloration ratio. Furthermore, a thermal expansion test up to 1400 ° C. was performed using a test coating sample (20 mm × 20 mm × 70 mm in length), and changes in the residual line when cooled to room temperature were measured. 4 ° C / min). The residual line change rate was determined based on the sample length after shrinkage from the sample length after heating to 1400 ° C. and cooling the sample to room temperature based on the sample length before firing. The results are shown in Table 2. In addition, about the case of Example 1 and Comparative Examples 1 and 2, the change of the thermal expansion coefficient by a thermal expansion test is shown in FIGS. 1-3, respectively.
比較例１は従来のアルミナ単独使用のケースである。亀裂が生成し、残存線変化率が大きく、耐ＦｅＯ性に劣ることが分る。比較例２は粒径が１ｍｍを超えるＣＡ６を含むケースであり、Al2O3との反応が起きづらく、ＣＡ６の生成や二次スピネルの生成ができ難くなるため膨張せず、残存線変化が大きくなった。比較例３及び４は、ＣＡ６と粒径が１ｍｍを超えるアルミナ又はスピネルを併用したケースであるが、新たなＣＡ６や二次スピネルが生成しづらく、収縮が大きいために亀裂が生成したものと考えられる。比較例６は、結晶質ファイバーを含まないケースであり、残存収縮が大きく、耐ＦｅＯ性に劣る。これに対し、実施例1〜１０のコーティング材は、ＣＡ６単独使用ケース、及びＣＡ６と共に粒径１ｍｍ以下のスピネル又はアルミナを併用したケースであり、いずれも高温での収縮が抑制され、残存収縮も少なく、亀裂が生成せず、尚且つ、耐ＦｅＯ性に優れることが分る。また、嵩比重も小さく、軽量断熱質である。 Comparative Example 1 is a case of using conventional alumina alone. It can be seen that cracks are generated, the residual line change rate is large, and the FeO resistance is poor. Comparative Example 2 is a case containing CA6 having a particle size exceeding 1 mm, and it is difficult for the reaction with Al 2 O 3 to occur, and it is difficult to generate CA6 and secondary spinel, so that expansion does not occur and residual line changes occur. It became bigger. Comparative Examples 3 and 4 are cases in which CA6 and alumina or spinel with a particle size exceeding 1 mm are used in combination, but it is difficult to generate new CA6 and secondary spinel, and cracks are generated due to large shrinkage. It is done. Comparative Example 6 is a case containing no crystalline fiber, has a large residual shrinkage, and is inferior in FeO resistance. On the other hand, the coating materials of Examples 1 to 10 are a case where CA6 is used alone and a case where spinel or alumina having a particle diameter of 1 mm or less is used in combination with CA6, both of which are suppressed from shrinkage at high temperatures and have residual shrinkage. It can be seen that there are few, no cracks are formed, and the FeO resistance is excellent. Moreover, the bulk specific gravity is also small, and it is a lightweight heat insulating material.
この理由について、図１及び２に示したように、常温から１４００℃まで４℃/minの昇温速度で昇温した場合の熱膨張率曲線と、その後、４℃/minの冷却速度で常温まで降温した場合の熱膨張曲線とを測定すると、骨材としてアルミナを単独で含んだコーティング材（比較例１）の場合には、図２から明らかなように、高温で収縮することから、このような高温から冷間に冷やす際の残存収縮が大きいことが分かる。また、粒径１ｍｍを超えるＣＡ６原料と共にアルミナを併用したコーティング材（比較例２）では、ＣＡ６とアルミナの反応が起きづらく、新たなＣＡ６が生成しなかったため、残存収縮が大きくなったものと考えられる。これらに対し、骨材として粒径１ｍｍ以下のＣＡ６原料を単独で用いた場合（実施例１）では、図１から明らかなように、その残存収縮は図２の場合に比べてはるかに小さいことが分かる。なお、粒径１ｍｍ以下のＣＡ６原料と共に所定のアルミナ又はスピネルを併用した場合（実施例２〜１０）には、新たなＣＡ６やアルミナリッチな二次スピネルが生成して原料が膨張し、その膨張により収縮が抑制されて亀裂が防止され、また、熱間での収縮が抑制されることで、残存収縮が小さくなったと考えられる。 For this reason, as shown in FIGS. 1 and 2, the coefficient of thermal expansion when the temperature is raised from room temperature to 1400 ° C. at a rate of 4 ° C./min, and then at room temperature at a rate of 4 ° C./min. When measuring the thermal expansion curve when the temperature is lowered to, in the case of the coating material containing only alumina as an aggregate (Comparative Example 1), as is apparent from FIG. It can be seen that the residual shrinkage when cooling from high temperature to cold is large. In addition, in the coating material (comparative example 2) in which alumina is used in combination with a CA6 raw material having a particle diameter of more than 1 mm, the reaction between CA6 and alumina is difficult to occur, and new CA6 was not generated. It is done. On the other hand, when a CA6 raw material having a particle size of 1 mm or less is used alone as an aggregate (Example 1), as is apparent from FIG. 1, the residual shrinkage is much smaller than that in FIG. I understand. In addition, when a predetermined alumina or spinel is used in combination with a CA6 raw material having a particle size of 1 mm or less (Examples 2 to 10), new CA6 or alumina-rich secondary spinel is generated, and the raw material expands. Thus, it is considered that the shrinkage is suppressed and cracks are prevented, and the residual shrinkage is reduced by suppressing the hot shrinkage.
また、上記実施例１及び２、並びに比較例１で得られたコーティング材をＡ製鉄所熱延加熱炉天井ブロック（耐熱温度１６００℃のセラミックファイバー使用）にスプレーガンにて２ｍｍ厚で施工したところ、４ヶ月後の炉内点検で、比較例１のコーティング材はＦｅＯと反応し、亀裂が生成し剥離していたが、実施例１及び２のコーティング材はＦｅＯとの反応は見られず、亀裂、剥離の生成はなかった。 In addition, when the coating material obtained in Examples 1 and 2 and Comparative Example 1 was applied to the A steelworks hot-rolled heating furnace ceiling block (using ceramic fiber with a heat-resistant temperature of 1600 ° C) with a spray gun to a thickness of 2 mm In the in-furnace inspection after 4 months, the coating material of Comparative Example 1 reacted with FeO and cracks were generated and peeled off, but the coating materials of Examples 1 and 2 showed no reaction with FeO, There was no generation of cracks or delamination.
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|---|---|---|---|---|
| WO2013035646A1 (en) * | 2011-09-08 | 2013-03-14 | 三菱樹脂株式会社 | Molded inorganic-fiber object |
| JP2015081753A (en) * | 2013-10-24 | 2015-04-27 | 新日鐵住金株式会社 | Inorganic fiber fireproof heat insulation lining construction method and furnace |
| JP2015081752A (en) * | 2013-10-24 | 2015-04-27 | 新日鐵住金株式会社 | Inorganic fibrous heat insulation material block and furnace provided with the same on inner wall |
| JP2016104899A (en) * | 2014-12-01 | 2016-06-09 | 黒崎播磨株式会社 | Precast block structure |
| JP2017072267A (en) * | 2015-10-05 | 2017-04-13 | 品川リフラクトリーズ株式会社 | Method for constructing lining for industrial kiln and lining for industrial kiln |
| KR20170084039A (en) | 2014-11-14 | 2017-07-19 | 미쯔비시 케미컬 주식회사 | Heat-insulating protective member for skid post, and method for applying heat-insulating protective member for skid post |
| JP2021088475A (en) * | 2019-12-03 | 2021-06-10 | デンカ株式会社 | Inorganic fiber molded product, heating furnace, structural body, and method for manufacturing inorganic fiber molded product |
| WO2023132182A1 (en) * | 2022-01-07 | 2023-07-13 | デンカ株式会社 | Ca6 particles and method for producing molded inorganic-fiber object using same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03159967A (en) * | 1989-11-20 | 1991-07-09 | Shinagawa Refract Co Ltd | Lining material of container for molten metal |
| JP2004500988A (en) * | 2000-05-31 | 2004-01-15 | ティーワイケー ユアロップ ゲーエムベーハー | Insulating material and method for coating spouts, pouring tubes, melt flow protection tubes, and other workpieces for pouring or transferring molten metal |
| JP2004168565A (en) * | 2002-11-18 | 2004-06-17 | Shinnikka Thermal Ceramics Corp | Scale-resistant coating material for heating furnace |
-
2009
- 2009-07-31 JP JP2009178677A patent/JP5110540B2/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03159967A (en) * | 1989-11-20 | 1991-07-09 | Shinagawa Refract Co Ltd | Lining material of container for molten metal |
| JP2004500988A (en) * | 2000-05-31 | 2004-01-15 | ティーワイケー ユアロップ ゲーエムベーハー | Insulating material and method for coating spouts, pouring tubes, melt flow protection tubes, and other workpieces for pouring or transferring molten metal |
| JP2004168565A (en) * | 2002-11-18 | 2004-06-17 | Shinnikka Thermal Ceramics Corp | Scale-resistant coating material for heating furnace |
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| WO2013035646A1 (en) * | 2011-09-08 | 2013-03-14 | 三菱樹脂株式会社 | Molded inorganic-fiber object |
| JP5376097B2 (en) * | 2011-09-08 | 2013-12-25 | 三菱樹脂株式会社 | Inorganic fiber molded body |
| JP2015081753A (en) * | 2013-10-24 | 2015-04-27 | 新日鐵住金株式会社 | Inorganic fiber fireproof heat insulation lining construction method and furnace |
| JP2015081752A (en) * | 2013-10-24 | 2015-04-27 | 新日鐵住金株式会社 | Inorganic fibrous heat insulation material block and furnace provided with the same on inner wall |
| KR20170084039A (en) | 2014-11-14 | 2017-07-19 | 미쯔비시 케미컬 주식회사 | Heat-insulating protective member for skid post, and method for applying heat-insulating protective member for skid post |
| US10590598B2 (en) | 2014-11-14 | 2020-03-17 | Mitsubishi Chemical Corporation | Heat-insulating protective member for skid post and method for applying the heat-insulating protective member for skid post |
| JP2016104899A (en) * | 2014-12-01 | 2016-06-09 | 黒崎播磨株式会社 | Precast block structure |
| JP2017072267A (en) * | 2015-10-05 | 2017-04-13 | 品川リフラクトリーズ株式会社 | Method for constructing lining for industrial kiln and lining for industrial kiln |
| JP2021088475A (en) * | 2019-12-03 | 2021-06-10 | デンカ株式会社 | Inorganic fiber molded product, heating furnace, structural body, and method for manufacturing inorganic fiber molded product |
| CN114746379A (en) * | 2019-12-03 | 2022-07-12 | 电化株式会社 | Inorganic fiber molded body, heating furnace, structure, and method for producing inorganic fiber molded body |
| CN114746379B (en) * | 2019-12-03 | 2023-08-08 | 电化株式会社 | Inorganic fiber molded body, heating furnace, structure, and method for producing inorganic fiber molded body |
| WO2023132182A1 (en) * | 2022-01-07 | 2023-07-13 | デンカ株式会社 | Ca6 particles and method for producing molded inorganic-fiber object using same |
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