JP6694541B1 - Castable refractory for blast furnace gutter metal part - Google Patents
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Abstract
【課題】高炉樋メタル部用のキャスタブル耐火物において、穴あき現象の発生を抑制する。【解決手段】耐火原料及び結合剤を含有し、高炉樋の内張りのメタル部に適用される高炉樋メタル部用のキャスタブル耐火物であって、前記耐火原料１００質量％に占める割合で、炭素質原料を５質量％以上１５質量％以下、炭化珪素原料を８質量％以上２０質量％以下、炭化硼素を０．１質量％以上２質量％以下含有し、粒径７５μｍ未満の粒子の含有量が前記耐火原料１００質量％に占める割合で１５質量％以上３０質量％以下であり、前記炭化珪素原料のうち粒径１μｍ以上２０μｍ以下の炭化珪素超微粉の含有量が前記耐火原料１００質量％に占める割合で０．１質量％以上５質量％以下であり、前記耐火原料の残部は、主としてスピネル原料及びアルミナ原料の少なくとも１つからなる。【選択図】なしPROBLEM TO BE SOLVED: To suppress the occurrence of a perforation phenomenon in a castable refractory for a blast furnace gutter metal part. A castable refractory for a blast furnace gutter metal part, which contains a refractory raw material and a binder and is applied to a metal part of a lining of a blast furnace gutter, wherein the carbonaceous material is contained in a proportion of 100% by mass of the refractory raw material. 5 mass% or more and 15 mass% or less of raw materials, 8 mass% or more and 20 mass% or less of silicon carbide raw materials, 0.1 mass% or more and 2 mass% or less of boron carbide, and the content of particles having a particle size of less than 75 μm is It is 15% by mass or more and 30% by mass or less based on 100% by mass of the refractory raw material, and the content of silicon carbide ultrafine powder having a particle size of 1 μm or more and 20 μm or less in the silicon carbide raw material occupies 100% by mass of the refractory raw material. The proportion is 0.1% by mass or more and 5% by mass or less, and the balance of the refractory raw material is mainly composed of at least one of spinel raw material and alumina raw material. [Selection diagram] None
Description
本発明は、高炉樋の内張りのメタル部に適用される、高炉樋メタル部用のキャスタブル耐火物に関する。 The present invention relates to a castable refractory for a blast furnace gutter metal part, which is applied to a metal part of a blast furnace gutter lining.
高炉樋は、高炉から出銑した溶銑が取鍋、混銑車等に至る通路の役割をもつ。近年、その内張りには施工性の面から、従来のれんが積みに替えてキャスタブル耐火物が使用されている。また、高炉樋の内張りのキャスタブル耐火物の施工においては、一般的に、スラグ部（スラグゾーンとも呼ばれる。）とメタル部（メタルゾーンとも呼ばれる。）とを異なる材質で施工する、いわゆるゾーンライニングが行われている。
メタル部に用いられるキャスタブル耐火物（メタル材）には、耐メタル性は元より耐スラグ性も求められるところ、メタル材において耐スラグ性を確保するために、炭素質原料を添加する技術が知られている（例えば、特許文献１参照）。
The blast furnace gutter serves as a passage for the hot metal tapped from the blast furnace to reach a ladle, a mixed pig iron car, and the like. In recent years, castable refractories have been used for the lining instead of conventional bricks in terms of workability. Further, in the construction of castable refractory linings of blast furnace gutters, generally, so-called zone lining is used in which the slag portion (also called slag zone) and the metal portion (also called metal zone) are made of different materials. Has been done.
Castable refractory (metal material) used in the metal part requires not only metal resistance but also slag resistance. However, in order to secure slag resistance in metal materials, technology to add carbonaceous raw material is known. (For example, see Patent Document 1).
ここで、高炉樋の一般的な内張り構造は、図１に模式的に示すように、稼働面側から新材１、旧材２及びパーマ材３の３層構造であり、新材１及び旧材２には同一材質のメタル材（キャスタブル耐火物）が施工される。そして、稼働末期に新材１の残厚が薄くなると、新材１及び旧材２の一部を除去して新たに新材１を施工する。
なお、図１では、高炉樋の内張りのうちメタル部のみを示しており、その上方のスラグ部は省略している。また、図１において新材１の溶損が著しい部位は、スラグ流と溶銑流の界面部分に相当する、いわゆる「メタルライン」であり、メタル材はこのメタルラインを含むように施工される。
Here, the general lining structure of the blast furnace gutter is a three-layer structure of a
In FIG. 1, only the metal portion of the lining of the blast furnace gutter is shown, and the slag portion above it is omitted. Further, in FIG. 1, a portion where the melt loss of the
このような高炉樋の内張り構造において、本発明者らが新材１及び旧材２として炭素質原料を含有するメタル材により高炉樋のメタル部を施工して試験を重ねたところ、特に稼働末期に近づいて新材１の残厚が薄くなると、その新材１がブロック状に剥離する、いわゆる「穴あき現象」の発生が多く観察された。
In the lining structure of such a blast furnace gutter, the inventors of the present invention constructed a metal part of the blast furnace gutter using a metal material containing a carbonaceous raw material as the
本発明が解決しようとする課題は、高炉樋メタル部用のキャスタブル耐火物において、穴あき現象の発生を抑制することにある。 The problem to be solved by the present invention is to suppress the occurrence of a perforation phenomenon in a castable refractory for a blast furnace gutter metal part.
本発明者らが、穴あき現象の発生した高炉樋の内張り構造について、新材と旧材の施工体組織を観察及び分析したところ、特に旧材の施工体組織において炭素質原料の酸化がみられ、その炭素質原料の酸化により旧材の施工体組織の劣化（高気孔率化、低強度化）が進み、その結果、新旧材間の組織差が顕著になっていることがわかった。すなわち、この新旧材間の組織差が穴あき現象発生の主たる原因であることがわかった。 The inventors of the present invention observed and analyzed the construction structures of the new material and the old material with respect to the lining structure of the blast furnace gutter in which the perforation phenomenon occurred, and particularly, the oxidation of the carbonaceous raw material was observed in the construction structure of the old material. It was found that the oxidation of the carbonaceous raw material led to deterioration of the structure of the old material (higher porosity and lower strength), and as a result, the difference in structure between the old and new materials became significant. That is, it was found that the difference in structure between the old and new materials is the main cause of the occurrence of the perforation phenomenon.
そこで本発明者らは、新旧材間の組織差を軽減するために旧材中の炭素質原料の酸化抑制を図ることとし、旧材の使用環境に応じた炭素質原料の酸化抑制手段を探求した。すなわち、旧材の稼働面側（新材側）は１２００℃以上の高温部となり、背面側（パーマ材側）は１２００℃未満の低温部になることから、これら高温部と低温部にそれぞれ有効な炭素質原料の酸化抑制手段を探求した。その結果、高温部における炭素質原料の酸化抑制には炭化珪素超微粉の適量添加が有効であり、低温部における炭素質原料の酸化抑制には炭化硼素の適量添加が有効であることがわかり、本発明を完成させるに至った。 Therefore, the inventors decided to suppress the oxidation of the carbonaceous raw material in the old material in order to reduce the structural difference between the old and new materials, and searched for a means for suppressing the oxidation of the carbonaceous raw material according to the usage environment of the old material. did. That is, the operating surface side (new material side) of the old material is a high temperature part of 1200 ° C or higher, and the rear surface side (perm material side) is a low temperature part of less than 1200 ° C, so it is effective for these high temperature part and low temperature part respectively. We have sought a means for suppressing the oxidation of various carbonaceous raw materials. As a result, it was found that the addition of an appropriate amount of ultrafine silicon carbide powder is effective for suppressing the oxidation of the carbonaceous raw material in the high temperature part, and the addition of an appropriate amount of boron carbide is effective for suppressing the oxidation of the carbonaceous raw material in the low temperature part, The present invention has been completed.
すなわち、本発明の一観点によれば、次の高炉樋メタル部用のキャスタブル耐火物（メタル材）が提供される。
耐火原料及び結合剤を含有し、高炉樋の内張りのメタル部に適用される高炉樋メタル部用のキャスタブル耐火物であって、
前記耐火原料１００質量％に占める割合で、炭素質原料を５質量％以上１５質量％以下、炭化珪素原料を８質量％以上２０質量％以下、炭化硼素を０．１質量％以上２質量％以下含有し、
粒径７５μｍ未満の粒子の含有量が前記耐火原料１００質量％に占める割合で１５質量％以上３０質量％以下であり、
前記炭化珪素原料のうち粒径１μｍ以上２０μｍ以下の炭化珪素超微粉の含有量が前記耐火原料１００質量％に占める割合で０．５質量％以上２質量％以下であり、
前記耐火原料の残部は、主としてスピネル原料及びアルミナ原料の少なくとも１つからなる、高炉樋メタル部用のキャスタブル耐火物。
That is, according to one aspect of the present invention, there is provided a castable refractory (metal material) for the following blast furnace gutter metal part.
A castable refractory for a blast furnace gutter metal part, which contains a refractory raw material and a binder and is applied to a metal part of a blast furnace gutter lining,
The carbonaceous raw material is 5% by mass or more and 15% by mass or less, the silicon carbide raw material is 8% by mass or more and 20% by mass or less, and the boron carbide is 0.1% by mass or more and 2% by mass or less in proportion to 100% by mass of the refractory raw material. Contains,
The content of particles having a particle size of less than 75 μm is 15% by mass or more and 30% by mass or less in proportion to 100% by mass of the refractory raw material,
The content of the ultrafine silicon carbide powder having a particle size of 1 μm or more and 20 μm or less in the silicon carbide raw material is 0.5 % by mass or more and 2 % by mass or less in a ratio of 100% by mass of the refractory raw material,
A castable refractory for a blast furnace gutter metal part, wherein the balance of the refractory raw material is mainly at least one of spinel raw material and alumina raw material.
なお、本発明において炭化珪素超微粉の粒経特定は、超微粉の粒径測定に最も一般的なレーザー回折式粒度測定装置によるもので、超微粉以外の耐火原料の粒径特定はＪＩＳふるい目開きによるものである。 In the present invention, the particle size of silicon carbide ultrafine powder is determined by a laser diffraction type particle size measuring device, which is the most common method for measuring the particle size of ultrafine powder, and the particle size of refractory raw materials other than ultrafine powder is specified by JIS sieve. It is due to the opening.
本発明によれば、高炉樋の内張り構造において新旧材間の組織差を軽減することができ、これにより高炉樋メタル部用のキャスタブル耐火物において穴あき現象の発生を抑制することができる。 According to the present invention, it is possible to reduce the structural difference between the old and new materials in the lining structure of the blast furnace gutter, and thereby to suppress the occurrence of the perforation phenomenon in the castable refractory for the blast furnace gutter metal part.
本発明のキャスタブル耐火物は、耐火原料及び結合剤を含有し、高炉樋の内張りのメタル部に適用されるメタル材であり、具体的には、耐火原料として、炭素質原料、粒径１μｍ以上２０μｍ以下の炭化珪素超微粉を含む炭化珪素原料、炭化硼素、並びにスピネル原料及びアルミナ原料の少なくとも１つを含有する。 The castable refractory of the present invention is a metal material containing a refractory raw material and a binder and applied to the metal part of the lining of a blast furnace gutter. Specifically, as the refractory raw material, a carbonaceous raw material, a particle size of 1 μm or more It contains at least one of a silicon carbide raw material containing ultrafine silicon carbide powder of 20 μm or less, boron carbide, and a spinel raw material and an alumina raw material.
炭素質原料は、主として耐スラグ性を確保するために、耐火原料１００質量％に占める割合で５質量％以上１５質量％以下の範囲内で含有する。炭素質原料の含有量が５質量％未満であると耐スラグ性が低下する。一方、炭素質原料の含有量が１５質量％超であると、炭素質原料はスピネル原料やアルミナ原料ほど分散性が高くないことに加え、かさ比重が低いので自重がかかりにくいため流動性が低下する。また、炭素質原料は親水性が低いので、施工体の曲げ強度も低下する。炭素質原料の含有量は６質量％以上１０質量％以下であることが好ましい。 The carbonaceous raw material is contained in the range of 5% by mass or more and 15% by mass or less in proportion to 100% by mass of the refractory raw material mainly in order to secure slag resistance. If the content of the carbonaceous raw material is less than 5% by mass, the slag resistance decreases. On the other hand, if the content of the carbonaceous raw material is more than 15% by mass, the carbonaceous raw material is not as dispersible as the spinel raw material and the alumina raw material, and in addition, since the bulk specific gravity is low, the self-weight is less likely to occur, and thus the fluidity decreases To do. In addition, since the carbonaceous raw material has low hydrophilicity, the bending strength of the construction body also decreases. The content of the carbonaceous raw material is preferably 6% by mass or more and 10% by mass or less.
炭素質原料としては、一般的な高炉樋用キャスタブル耐火物に使用されているものを使用するすることができ、具体例としては、ピッチ、メソフェーズピッチ、カーボンブラック、人造黒鉛、りん状黒鉛、土状黒鉛、コークス、無煙炭等である。また、炭素質原料の粒度構成も、一般的な高炉樋用キャスタブル耐火物に使用される炭素質原料と同様でよく、例えば、粒径２ｍｍ未満の範囲で適宜の粒度構成とすることができる。 As the carbonaceous raw material, it is possible to use those used for castable refractories for general blast furnace gutters, and specific examples thereof include pitch, mesophase pitch, carbon black, artificial graphite, phosphorous graphite, and soil. Graphite, coke, anthracite, etc. Further, the particle size composition of the carbonaceous raw material may be the same as that of the carbonaceous material used for the general castable refractory for blast furnace gutter, and for example, an appropriate particle size configuration can be adopted within a particle size range of less than 2 mm.
炭化珪素原料は、主として耐スラグ性を確保するために、耐火原料１００質量％に占める割合で８質量％以上２０質量％以下の範囲内で含有する。炭化珪素原料の含有量が８質量％未満であると耐スラグ性が低下する。一方、炭化珪素原料の含有量が２０質量％超であると、過剰にＳｉＯ２が生成されてしまい耐メタル性が低下する。すなわち、炭化珪素原料は、１１００〜１２００℃程度の高温になると施工体内部雰囲気中のＣＯガスとの反応により、ＳｉＯ２を生成する。このＳｉＯ２は後述のとおり高温部（１２００℃以上）において炭素質原料の酸化を抑制する効果を発揮するが、過剰に生成されると、他の耐火原料（スピネル原料、アルミナ原料等）と反応してＳｉＯ２系の低融物を生成し、その結果、耐メタル性が低下する。炭化珪素原料の含有量は１２質量％以上１８質量％以下であることが好ましい。 The silicon carbide raw material is contained mainly in order to secure slag resistance within a range of 8% by mass or more and 20% by mass or less based on 100% by mass of the refractory raw material. If the content of the silicon carbide raw material is less than 8% by mass, the slag resistance decreases. On the other hand, when the content of the silicon carbide raw material is more than 20% by mass, excessive SiO 2 is produced and the metal resistance is lowered. That is, when the silicon carbide raw material reaches a high temperature of about 1100 to 1200 ° C., it reacts with CO gas in the atmosphere inside the construction body to produce SiO 2 . As will be described later, this SiO 2 has an effect of suppressing the oxidation of the carbonaceous raw material in the high temperature portion (1200 ° C. or higher), but if excessively produced, it reacts with other refractory raw materials (spinel raw material, alumina raw material, etc.). As a result, a SiO 2 -based low-melt material is generated, and as a result, metal resistance is reduced. The content of the silicon carbide raw material is preferably 12% by mass or more and 18% by mass or less.
本発明のキャスタブル耐火物は、炭化珪素原料の一部として粒径１μｍ以上２０μｍ以下の炭化珪素超微粉（以下、単に「炭化珪素超微粉」という。）を含有する。その含有量は耐火原料１００質量％に占める割合で０．１質量％以上５質量％以下である。この炭化珪素超微粉は、上述のとおり高温時にＳｉＯ２を生成し、このＳｉＯ２は高温部（１２００℃以上）において炭素質原料の酸化を抑制する効果を発揮する。具体的にはＳｉＯ２系のガラス層が炭素質原料を被覆することで炭素質原料の酸化を抑制する。したがって、炭化珪素超微粉の含有が０．１質量％未満であると、高温部（１２００℃以上）において炭素質原料の酸化を抑制する効果が十分に発揮されず、特に旧材の高温部（新材側）において炭素質原料が酸化し施工体組織が劣化（高気孔率化、低強度化）する。これにより、新旧材間の組織差が顕著になり、穴あき現象が発生する。また、炭素質原料が酸化・消失することによる施工体組織の高気孔率化によって耐スラグ性も低下する。
一方、炭化珪素超微粉の含有量が５質量％超であると、過剰にＳｉＯ２が生成されてしまい耐メタル性が低下する。また、ＳｉＯ２系のガラス層が過剰に生成されるので、過焼結作用が進んでしまい耐スポーリング性も低下する。
炭化珪素超微粉の含有量は０．５質量％以上２質量％以下であることが好ましい。
なお、炭化珪素超微粉は炭化珪素原料であり、炭化珪素超微粉の含有量は炭化珪素原料の含有量に合算される。すなわち、本発明では炭化珪素原料の一部として炭化珪素超微粉を使用する。
The castable refractory material of the present invention contains ultrafine silicon carbide powder having a particle size of 1 μm or more and 20 μm or less (hereinafter simply referred to as “ultrafine silicon carbide powder”) as a part of the silicon carbide raw material. The content thereof is 0.1% by mass or more and 5% by mass or less based on 100% by mass of the refractory raw material. The silicon carbide ultrafine powder is a SiO 2 generated at high temperatures as described above, the SiO 2 exhibits an effect of suppressing the oxidation of the carbonaceous feedstock in the hot section (1200 ° C. or higher). Specifically, the SiO 2 glass layer covers the carbonaceous raw material to suppress the oxidation of the carbonaceous raw material. Therefore, if the content of the ultrafine silicon carbide powder is less than 0.1% by mass, the effect of suppressing the oxidation of the carbonaceous raw material in the high temperature portion (1200 ° C or higher) is not sufficiently exerted, and particularly in the high temperature portion of the old material ( In the new material side, the carbonaceous raw material is oxidized and the structure of the construction body deteriorates (higher porosity and lower strength). As a result, the difference in structure between the old and new materials becomes noticeable, and the phenomenon of perforation occurs. In addition, the slag resistance also decreases due to the high porosity of the structure of the construction body due to the oxidation and disappearance of the carbonaceous raw material.
On the other hand, if the content of the ultrafine silicon carbide powder is more than 5% by mass, excessive SiO 2 is produced and the metal resistance is lowered. Further, since the SiO 2 glass layer is excessively formed, the oversintering action is promoted, and the spalling resistance is reduced.
The content of the ultrafine silicon carbide powder is preferably 0.5% by mass or more and 2% by mass or less.
Silicon carbide ultrafine powder is a silicon carbide raw material, and the content of silicon carbide ultrafine powder is added to the content of silicon carbide raw material. That is, in the present invention, ultrafine silicon carbide powder is used as a part of the silicon carbide raw material.
炭化硼素は、主に低温部（１２００℃未満）において炭素質原料の酸化を抑制するために、耐火原料１００質量％に占める割合で０．１質量％以上２質量％以下の範囲内で含有する。炭化硼素は、６００℃程度の低温で酸化し硼珪酸ガラスを生成し、この硼珪酸ガラスが炭素質原料を被覆することで炭素質原料の酸化を抑制する効果を発揮する。したがって、炭化硼素の含有量が０．１質量％未満であると、低温部（１２００℃未満）において炭素質原料の酸化を抑制する効果が発揮されず、特に旧材の低温部（背面側）において炭素質原料が酸化し施工体組織が劣化（高気孔率化、低強度化）する。これにより、新旧材間の組織差が顕著になり、穴あき現象が発生する。また、炭素質原料が酸化・消失することによる施工体組織の高気孔率化によって耐スラグ性も低下する。
一方、炭化硼素の含有量が２質量％超であると、硼珪酸ガラスが過剰に生成されるので、過焼結作用が進んでしまい耐スポーリング性が低下する。また、硼珪酸ガラスの量が多くなると、耐メタル性が低下する。
炭化硼素の含有量は０．２質量％以上１質量％以下であることが好ましい。
Boron carbide is contained in the range of 0.1% by mass or more and 2% by mass or less in proportion to 100% by mass of the refractory raw material in order to suppress the oxidation of the carbonaceous raw material mainly in the low temperature part (less than 1200 ° C.). .. Boron carbide oxidizes at a low temperature of about 600 ° C. to form borosilicate glass, and the borosilicate glass coats the carbonaceous raw material to exert an effect of suppressing the oxidation of the carbonaceous raw material. Therefore, when the content of boron carbide is less than 0.1% by mass, the effect of suppressing the oxidation of the carbonaceous raw material is not exhibited in the low temperature portion (less than 1200 ° C.), and particularly in the low temperature portion (back surface side) of the old material. In, the carbonaceous raw material is oxidized and the structure of the construction body is deteriorated (high porosity, low strength). As a result, the difference in structure between the old and new materials becomes noticeable, and the phenomenon of perforation occurs. In addition, the slag resistance also decreases due to the high porosity of the structure of the construction body due to the oxidation and disappearance of the carbonaceous raw material.
On the other hand, when the content of boron carbide is more than 2% by mass, borosilicate glass is excessively produced, so that the oversintering action is promoted and the spalling resistance is deteriorated. In addition, when the amount of borosilicate glass increases, the metal resistance decreases.
The content of boron carbide is preferably 0.2% by mass or more and 1% by mass or less.
以上のとおり本発明のキャスタブル耐火物は、耐火原料として炭素質原料、炭化珪素原料及び炭化硼素を含有するが、耐火原料の残部は、主としてスピネル原料及びアルミナ原料の少なくとも１つからなる。なお、耐火原料の残部として挙げた上記原料は、耐火原料の残部の「主として」であり、耐火原料の残部には上記原料以外の耐火原料、例えば粘土等も含み得る。 As described above, the castable refractory of the present invention contains a carbonaceous raw material, a silicon carbide raw material, and boron carbide as a refractory raw material, but the balance of the refractory raw material is mainly at least one of a spinel raw material and an alumina raw material. The above-mentioned raw materials mentioned as the rest of the refractory raw material are “mainly” the rest of the refractory raw material, and the rest of the refractory raw material may include refractory raw materials other than the above raw materials, such as clay.
本発明のキャスタブル耐火物において耐火原料全体としての粒度構成は、粒径７５μｍ未満の粒子の含有量が耐火原料１００質量％に占める割合で１５質量％以上３０質量％以下である。粒径７５μｍ未満の粒子の含有量が１５質量％未満であると、流動性が低下する。また、施工体組織の緻密性が低下するので、耐スラグ性、耐メタル性及び強度も低下する。一方、粒径７５μｍ未満の粒子の含有量が３０質量％超であると、マトリクスが先行溶損して耐スラグ性及び耐メタル性が低下すると共に、過焼結作用が進んでしまい耐スポーリング性が低下する。粒径７５μｍ未満の粒子の含有量は２３質量％以上２９質量％以下であることが好ましい。 In the castable refractory of the present invention, the particle size composition of the entire refractory raw material is 15% by mass or more and 30% by mass or less as a proportion of the content of particles having a particle size of less than 75 μm in 100% by mass of the refractory raw material. If the content of particles having a particle size of less than 75 μm is less than 15% by mass, the fluidity will be reduced. Further, since the compactness of the construction body structure is lowered, slag resistance, metal resistance and strength are also lowered. On the other hand, when the content of particles having a particle size of less than 75 μm exceeds 30% by mass, the matrix is preliminarily melt-damaged to deteriorate the slag resistance and the metal resistance, and the oversintering action is promoted, resulting in spalling resistance. Is reduced. The content of particles having a particle size of less than 75 μm is preferably 23% by mass or more and 29% by mass or less.
本発明のキャスタブル耐火物は、上述の耐火原料に加えて結合剤を含有する。結合剤の具体例は、アルミナセメント、マグネシアセメント等である。この結合剤は耐火原料１００質量％に対して外掛けで添加する。その添加量は、一般的な高炉樋用のキャスタブル耐火物と同等でよく、例えば耐火原料１００質量％に対して１〜６質量％以下程度である。 The castable refractory material of the present invention contains a binder in addition to the above-mentioned refractory raw material. Specific examples of the binder are alumina cement, magnesia cement and the like. This binder is externally added to 100% by mass of the refractory raw material. The addition amount thereof may be the same as that of a castable refractory for a general blast furnace gutter, and is, for example, about 1 to 6% by mass or less based on 100% by mass of the refractory raw material.
さらに本発明のキャスタブル耐火物は、分散剤、硬化調整剤、爆裂防止剤などの各種添加剤を適宜含有し得る。
分散剤は耐火物の施工時の流動性を付与するもので、具体例としては、トリポリリン酸ソーダ、ヘキサメタリン酸ソーダ、ウルトラポリリン酸ソーダ、酸性ヘキサメタリン酸ソーダ、ホウ酸ソーダ、炭酸ソーダ、ポリメタリン酸塩などの無機塩、クエン酸ソーダ、酒石酸ソーダ、ポリアクリル酸ソーダ、スルホン酸ソーダ、ポリカルボン酸塩、β−ナフタレンスルホン酸塩類、ナフタリンスルフォン酸等である。
硬化調整剤の具体例は、ホウ酸、ホウ酸アンモニウム、消石灰、炭酸ソーダ、炭酸リチウム等である。
爆裂防止剤の具体例は、有機質ファイバー、有機発泡剤、塩基性乳酸アルミニウム、金属アルミニウム等である。有機質ファイバーの具体例は、ビニロン（ポリビニールアルコールを含む）、レーヨン、ポリエステル、ナイロン、ポリプロピレン、ポリエチレンなどの高分子有機質ファイバーである。
なお、これら添加剤は耐火原料１００質量％に対して外掛けで添加する。その添加量は、一般的な高炉樋用のキャスタブル耐火物と同等でよい。
Furthermore, the castable refractory material of the present invention may appropriately contain various additives such as a dispersant, a curing modifier and an explosion proof agent.
The dispersant imparts fluidity during the construction of the refractory, and specific examples thereof include sodium tripolyphosphate, sodium hexametaphosphate, sodium ultrapolyphosphate, acidic sodium hexametaphosphate, sodium borate, sodium carbonate, and polymetaphosphate. Inorganic salts such as, sodium citrate, sodium tartrate, sodium polyacrylate, sodium sulfonate, polycarboxylic acid salts, β-naphthalenesulfonic acid salts, naphthalenesulfonic acid and the like.
Specific examples of the curing modifier are boric acid, ammonium borate, slaked lime, sodium carbonate, lithium carbonate and the like.
Specific examples of the explosion proof agent include organic fibers, organic foaming agents, basic aluminum lactate, metallic aluminum and the like. Specific examples of the organic fibers are polymer organic fibers such as vinylon (including polyvinyl alcohol), rayon, polyester, nylon, polypropylene and polyethylene.
Note that these additives are externally added to 100% by mass of the refractory raw material. The amount of addition may be the same as that of castable refractories for general blast furnace gutters.
なお、本発明のキャスタブル耐火物は、以上の耐火原料、結合剤及び添加剤のほかに、粒径８ｍｍ以上の大粗粒を含有することもできる。この大粗粒は耐火物組織に発生した亀裂の進展を防止する役割をもち、その材質としては、アルミナ、スピネル、炭化珪素あるいはこれらを主材とした耐火物廃材を使用することができるが、本発明のキャスタブル耐火物において大粗粒は耐火原料に含まれないものとする。すなわち、本発明のキャスタブル耐火物において大粗粒は耐火原料１００質量％に対して外掛けで添加するものとする。 The castable refractory material of the present invention may contain large coarse particles having a particle diameter of 8 mm or more in addition to the above-mentioned refractory raw materials, binders and additives. The large coarse particles have a role of preventing the development of cracks generated in the refractory structure, and as the material thereof, alumina, spinel, silicon carbide or a refractory waste material containing these as main materials can be used. In the castable refractory of the present invention, large coarse particles are not included in the refractory raw material. That is, in the castable refractory of the present invention, large coarse particles are added to 100% by mass of the refractory raw material by external multiplication.
本発明のキャスタブル耐火物の施工は、従来材質と同様、施工水を適量（例えば外掛けで４〜８質量％程度）添加・混合し、流し込み施工する。 In the construction of the castable refractory of the present invention, as in the case of the conventional material, an appropriate amount of construction water (for example, about 4 to 8% by mass on the outside) is added and mixed, and the castable refractory is poured.
表１及び表２に示す各例の耐火原料配合物１００質量％に対して外掛けで結合剤（アルミナセメント）を２〜４質量％添加してなるキャスタブル耐火物に、施工水を外掛けで５質量％添加・混合して得た不定形耐火物について、耐スラグ性、耐メタル性、耐スポーリング性、流動性、曲げ強度及び見掛気孔率を以下の要領で評価すると共に、各評価結果から総合評価を行った。 Casting refractory made by adding 2 to 4% by mass of a binder (alumina cement) to 100% by mass of the refractory raw material mixture of each example shown in Table 1 and Table 2 by applying externally applied construction water The amorphous refractory obtained by adding and mixing 5% by mass was evaluated for slag resistance, metal resistance, spalling resistance, fluidity, bending strength and apparent porosity according to the following procedures and each evaluation A comprehensive evaluation was performed based on the results.
＜耐スラグ性＞
各例の不定形耐火物を所定の型枠に流し込み、養生及び乾燥させて試験片を得る。この試験片について、侵食剤を高炉スラグとする回転ドラム侵食試験法による侵食試験を実施する。侵食試験後、試験片の溶損寸法を測定し、実施例１の試験片の溶損寸法で割って１００倍した値を溶損指数として求める。この溶損指数が小さいほど、耐スラグ性に優れる。耐スラグ性の評価は、この溶損指数が、１１０以下の場合を◎（優）、１１０超１２０以下の場合を○（良）、１２０超の場合を×（不良）とする。
<Slag resistance>
The amorphous refractory material of each example is poured into a predetermined mold, cured and dried to obtain a test piece. An erosion test is carried out on this test piece by a rotating drum erosion test method using a blast furnace slag as the erosion agent. After the erosion test, the melt loss dimension of the test piece is measured, divided by the melt loss dimension of the test piece of Example 1 and multiplied by 100 to obtain a melt loss index. The smaller the melt loss index, the better the slag resistance. In the evaluation of slag resistance, when the melting loss index is 110 or less, ⊚ (excellent), when it is more than 110 and 120 or less, ◯ (good), and when it exceeds 120, x (bad).
＜耐メタル性＞
各例の不定形耐火物を所定の型枠に流し込み、養生及び乾燥させて試験片を得る。この試験片を高周波炉に内張りし、銑鉄を溶融させ所定の温度に保ち、銑鉄の上から高炉スラグを投入して侵食試験を実施する。侵食試験後、試験片の溶損寸法を測定し、実施例１の試験片の溶損寸法で割って１００倍した値を溶損指数として求める。この溶損指数が小さいほど、耐メタル性に優れる。耐メタル性の評価は、この溶損指数が、１１０以下の場合を◎（優）、１１０超１２０以下の場合を○（良）、１２０超の場合を×（不良）とする。
<Metal resistance>
The amorphous refractory material of each example is poured into a predetermined mold, cured and dried to obtain a test piece. This test piece is lined in a high-frequency furnace, the pig iron is melted and kept at a predetermined temperature, and a blast furnace slag is introduced from above the pig iron to carry out an erosion test. After the erosion test, the melt loss dimension of the test piece is measured, divided by the melt loss dimension of the test piece of Example 1 and multiplied by 100 to obtain a melt loss index. The smaller the melt loss index, the better the metal resistance. The metal resistance is evaluated as ⊚ (excellent) when the melting loss index is 110 or less, as ◯ (good) when the melting loss index is more than 110 and 120 or less, and as x (bad) when it is more than 120.
＜耐スポーリング性＞
各例の不定形耐火物を所定の型枠に流し込み、養生及び乾燥させて試験片を得る。この試験片について事前に１４５０℃還元雰囲気で焼成し、その後、酸化雰囲気で１４５０℃加熱、空冷する試験を１０回繰り返し、試験後、試験片の亀裂発生状況を弾性率測定により評価する。耐スポーリング性の評価は、実施例１の弾性率低下率を１００とする弾性率低下指数が１１０以下の場合を◎（優）、１１０超１２０以下の場合を○（良）、１２０超の場合を×（不良）とする。
<Spalling resistance>
The amorphous refractory material of each example is poured into a predetermined mold, cured and dried to obtain a test piece. The test piece is fired in a reducing atmosphere at 1450 ° C. in advance, and thereafter, a test of heating at 1450 ° C. in an oxidizing atmosphere and air cooling is repeated 10 times. After the test, the crack generation state of the test piece is evaluated by elastic modulus measurement. The evaluation of the spalling resistance is ◎ (excellent) when the elastic modulus decrease index with the elastic modulus decrease rate of Example 1 as 100 is 110 or less, ○ when it is more than 110 and 120 or less (good), and more than 120. The case is defined as x (defective).
＜流動性＞
各例の不定形耐火物について、ＪＩＳ Ｒ ２５２１に準拠してタップフロー値を求める。このタップフロー値が大きいほど、流動性に優れる。流動性の評価は、タップフロー値が１５０ｍｍ以上の場合を◎（優）、１３０ｍｍ以上１５０ｍｍ未満の場合を○（良）、１３０ｍｍ未満の場合を×（不良）とする。
<Liquidity>
For the irregular refractory material of each example, the tap flow value is determined according to JIS R 2521. The larger the tap flow value, the better the fluidity. The fluidity is evaluated as ⊚ (excellent) when the tap flow value is 150 mm or more, as ○ (good) when the tap flow value is 130 mm or more and less than 150 mm, and as x (bad) when it is less than 130 mm.
＜曲げ強度＞
各例の不定形耐火物を所定の型枠に流し込み、養生及び乾燥させて試験片を得る。この試験片を１０００℃又は１４５０℃の還元雰囲気で焼成し、焼成後の試験片についてＪＩＳ Ｒ ２５５３に準拠して曲げ強度を評価する。曲げ強度の評価は、実施例１の曲げ強度を１００とする曲げ強度指数が９０以上の場合を◎（優）、８０以上９０未満の場合を○（良）、８０未満の場合を×（不良）とする。
<Bending strength>
The amorphous refractory material of each example is poured into a predetermined mold, cured and dried to obtain a test piece. This test piece is fired in a reducing atmosphere at 1000 ° C. or 1450 ° C., and the bending strength of the fired test piece is evaluated according to JIS R 2553. The bending strength was evaluated as follows: ◎ (excellent) when the bending strength index of Example 1 is 100 or more and 90 or more, ○ (good) when 80 or more and less than 90, and × (poor when less than 80). ).
＜見掛気孔率＞
各例の不定形耐火物を所定の型枠に流し込み、養生及び乾燥させて試験片を得る。この試験片を１０００℃酸化雰囲気で焼成し、焼成後の試験片ついてＪＩＳ Ｒ ２２０５に準拠して見掛気孔率を評価する。各例の見掛気孔率を実施例１の見掛気孔率で割って１００倍した値を見掛気孔率指数として求める。この見掛気孔率指数が小さいほど炭素質原料が酸化しておらず施工体の緻密性が高いということであり、言い換えれば、炭素質原料の酸化を抑制し、穴あき現象の発生を抑制する効果が高いということである。その評価は、見掛気孔率指数が１００以下の場合を◎（優）、１００超１１０未満の場合を〇（良）、１１０以上の場合を×（不良）とする。
<Apparent porosity>
The amorphous refractory material of each example is poured into a predetermined mold, cured and dried to obtain a test piece. This test piece is fired in an oxidizing atmosphere at 1000 ° C., and the apparent porosity of the fired test piece is evaluated according to JIS R 2205. The apparent porosity of each example is divided by the apparent porosity of Example 1 and multiplied by 100 to obtain the apparent porosity index. The smaller the apparent porosity index, the more the carbonaceous raw material is not oxidized and the denser the construction body is. In other words, the oxidation of the carbonaceous raw material is suppressed and the occurrence of the perforation phenomenon is suppressed. It means that the effect is high. The evaluation is ⊚ (excellent) when the apparent porosity index is 100 or less, ◯ (good) when the apparent porosity index is more than 100 and less than 110, and x (bad) when the apparent porosity index is 110 or more.
＜総合評価＞
全ての評価が◎の場合を◎（優）、×がなく少なくとも１つ○がある場合を○（良）、少なくとも１つ×がある場合を×（不良）とする。
<Comprehensive evaluation>
When all the evaluations are ⊚, ⊚ (excellent), when there is no x and at least one o is o (good), when at least one x is x (poor).
表１中、実施例１〜９、１２、１３は、いずれも本発明の範囲内にある例で、総合評価は◎（優）又は〇（良）であり、良好な結果が得られた。なかでも、炭素質原料の含有量、炭化珪素原料の含有量、炭化硼素の含有量、粒径７５μｍ未満の粒子の含有量、及び炭化珪素超微粉の含有量がいずれも上述の好ましい範囲内にある実施例１、実施例１２及び実施例１３は、総合評価が◎（優）であり、特に良好な結果が得られた。 In Table 1, Examples 1 to 9, 12, and 13 are all examples within the scope of the present invention, and the comprehensive evaluation was ⊚ (excellent) or ◯ (good), and good results were obtained. Among them, the content of carbonaceous raw material, the content of silicon carbide raw material, the content of boron carbide, the content of particles having a particle size of less than 75 μm, and the content of silicon carbide ultrafine powder are all within the above-mentioned preferred ranges. In certain Examples 1, 12, and 13, the overall evaluation was ⊚ (excellent), and particularly good results were obtained.
これに対して、表２に示す比較例１は炭素質原料の含有量が少なすぎる例で、耐スラグ性の評価が×（不良）となった。一方、比較例２は炭素質原料の含有量が多すぎる例で、流動性及び曲げ強度の評価が×（不良）となった。 On the other hand, Comparative Example 1 shown in Table 2 is an example in which the content of the carbonaceous raw material is too small, and the evaluation of the slag resistance was x (poor). On the other hand, Comparative Example 2 is an example in which the content of the carbonaceous raw material is too large, and the evaluations of fluidity and bending strength are x (poor).
比較例３は炭化珪素原料の含有量が少なすぎる例で、耐スラグ性の評価が×（不良）となった。また、炭化珪素原料から生成するＳｉＯ２による炭素質原料の酸化抑制効果が十分に得られず、見掛気孔率の評価も×（不良）となった。一方、比較例４は炭化珪素原料の含有量が多すぎる例で、耐メタル性の評価が×（不良）となった。 Comparative Example 3 is an example in which the content of the silicon carbide raw material is too small, and the slag resistance was evaluated as x (poor). Further, the effect of suppressing the oxidation of the carbonaceous raw material by SiO 2 generated from the silicon carbide raw material was not sufficiently obtained, and the evaluation of the apparent porosity was also x (poor). On the other hand, Comparative Example 4 is an example in which the content of the silicon carbide raw material is too large, and the metal resistance was evaluated as x (poor).
比較例５は炭化硼素の含有量が少なすぎる例で、炭化硼素から生成する硼珪酸ガラスによる炭素質原料の酸化抑制効果が十分に得られず、見掛気孔率の評価が×（不良）になると共に、耐スラグ性及び１０００℃焼成後の曲げ強度の評価も×（不良）となった。一方、比較例６は炭化硼素の含有量が多すぎる例で、耐メタル性及び耐スポーリング性の評価が×（不良）となった。 Comparative Example 5 is an example in which the content of boron carbide is too small, and the effect of suppressing the oxidation of the carbonaceous raw material by the borosilicate glass produced from boron carbide was not sufficiently obtained, and the apparent porosity was evaluated as x (poor). At the same time, the evaluation of the slag resistance and the bending strength after firing at 1000 ° C. also became x (poor). On the other hand, Comparative Example 6 is an example in which the content of boron carbide is too large, and the evaluation of metal resistance and spalling resistance was x (poor).
比較例７は粒径７５μｍ未満の粒子の含有量が少なすぎる例で、流動性の評価が×（不良）となった。また、施工体組織の緻密性が低下するので、耐スラグ性、耐メタル性及び曲げ強度の評価も×（不良）となった。一方、比較例８は粒径７５μｍ未満の粒子の含有量が多すぎる例で、耐スラグ性、耐メタル性及び耐スポーリング性の評価が×（不良）となった。 Comparative Example 7 is an example in which the content of particles having a particle size of less than 75 μm is too small, and the fluidity was evaluated as x (poor). In addition, since the compactness of the structure of the construction body is deteriorated, the evaluation of the slag resistance, the metal resistance, and the bending strength was x (poor). On the other hand, Comparative Example 8 is an example in which the content of particles having a particle size of less than 75 μm is too large, and the evaluation of slag resistance, metal resistance and spalling resistance is x (poor).
比較例９は炭化珪素超微粉の含有量が少なすぎる例で、炭化珪素原料から生成するＳｉＯ２による炭素質原料の酸化抑制効果が十分に得られず、見掛気孔率の評価が×（不良）となると共に、耐スラグ性及び１４５０℃焼成後の曲げ強度の評価も×（不良）となった。一方、比較例１０は炭化珪素超微粉の含有量が多すぎる例で、耐メタル性及び耐スポーリング性の評価が×（不良）となった。 Comparative Example 9 is an example in which the content of the ultrafine silicon carbide powder is too small, and the effect of suppressing the oxidation of the carbonaceous raw material by SiO 2 generated from the silicon carbide raw material was not sufficiently obtained, and the apparent porosity was evaluated as x (poor). ), The evaluation of the slag resistance and the bending strength after firing at 1450 ° C. also became x (poor). On the other hand, Comparative Example 10 is an example in which the content of the ultrafine silicon carbide powder is too large, and the evaluation of metal resistance and spalling resistance was x (poor).
１ 新材
２ 旧材
３ パーマ材
1
Claims (2)
前記耐火原料１００質量％に占める割合で、炭素質原料を５質量％以上１５質量％以下、炭化珪素原料を８質量％以上２０質量％以下、炭化硼素を０．１質量％以上２質量％以下含有し、
粒径７５μｍ未満の粒子の含有量が前記耐火原料１００質量％に占める割合で１５質量％以上３０質量％以下であり、
前記炭化珪素原料のうち粒径１μｍ以上２０μｍ以下の炭化珪素超微粉の含有量が前記耐火原料１００質量％に占める割合で０．５質量％以上２質量％以下であり、
前記耐火原料の残部は、主としてスピネル原料及びアルミナ原料の少なくとも１つからなる、高炉樋メタル部用のキャスタブル耐火物。 A castable refractory for a blast furnace gutter metal part, which contains a refractory raw material and a binder and is applied to a metal part of a blast furnace gutter lining,
The carbonaceous raw material is 5% by mass or more and 15% by mass or less, the silicon carbide raw material is 8% by mass or more and 20% by mass or less, and the boron carbide is 0.1% by mass or more and 2% by mass or less in proportion to 100% by mass of the refractory raw material. Contains,
The content of particles having a particle size of less than 75 μm is 15% by mass or more and 30% by mass or less in proportion to 100% by mass of the refractory raw material,
The content of the ultrafine silicon carbide powder having a particle size of 1 μm or more and 20 μm or less in the silicon carbide raw material is 0.5 % by mass or more and 2 % by mass or less in a ratio of 100% by mass of the refractory raw material,
A castable refractory for a blast furnace gutter metal part, wherein the balance of the refractory raw material is mainly at least one of spinel raw material and alumina raw material.
さらに、前記粒径７５μｍ未満の粒子の含有量が前記耐火原料１００質量％に占める割合で２３質量％以上２９質量％以下である、請求項１に記載の高炉樋メタル部用のキャスタブル耐火物。 The content of the carbonaceous raw material is 6% by mass or more and 10% by mass or less, the content of the silicon carbide raw material is 12% by mass or more and 18% by mass or less, and the content of the boron carbide is 100% by mass of the refractory raw material. The amount is 0.2% by mass or more and 1% by mass or less,
Furthermore, the particle content of the diameter 75μm below particles Ru der 29 mass% 23 mass% or more as a proportion of the refractory raw material 100 wt%, castable refractories for blast furnace trough metal part of claim 1 ..
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