JP3103480B2 - Method for producing zirconia refractory for thermal insulation - Google Patents
Method for producing zirconia refractory for thermal insulationInfo
- Publication number
- JP3103480B2 JP3103480B2 JP06135779A JP13577994A JP3103480B2 JP 3103480 B2 JP3103480 B2 JP 3103480B2 JP 06135779 A JP06135779 A JP 06135779A JP 13577994 A JP13577994 A JP 13577994A JP 3103480 B2 JP3103480 B2 JP 3103480B2
- Authority
- JP
- Japan
- Prior art keywords
- zirconia
- pore
- forming material
- particle size
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/02—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by adding chemical blowing agents
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/06—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Compositions Of Oxide Ceramics (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、１２００〜２２００℃
の高温から超高温域にて適用できる断熱用ジルコニア質
耐火物の製造方法に関するものである。BACKGROUND OF THE INVENTION
From the high temperature to a method for manufacturing a heat-insulating zirconia refractory that can be applied at very high temperature region.
【０００２】[0002]
【従来の技術】２２００℃に近い超高温域の酸化雰囲気
における耐火物として適する材質は蒸気圧が低く、化学
的に安定しているジルコニアである。ジルコニアは、融
点が約２８００℃であり、酸化物の中で最も安定した材
料の一つである。また、ジルコニアは、熱伝導率が比較
的低く、断熱性に優れているものの、通常の成形方法に
より製造できるジルコニア質耐火物の密度は７０％以上
(全気孔率３０％以下)である。ところが断熱性を上げる
目的で、これより更に密度を下げていく(気孔率を上げ
る)場合、強度の低下という問題が生じてくる。このた
め一般的に気孔部分を造るために、予めジルコニアを溶
融し中空にした軽量骨材を原料の一つとして使用してい
る。2. Description of the Related Art Zirconia, which has a low vapor pressure and is chemically stable, is suitable as a refractory in an oxidizing atmosphere in an ultra-high temperature range near 2200 ° C. Zirconia has a melting point of about 2800 ° C. and is one of the most stable materials among oxides. Further, zirconia has relatively low thermal conductivity and excellent heat insulation, but the density of zirconia refractories that can be produced by a normal molding method is 70% or more.
(Total porosity of 30% or less). However, when the density is further reduced (increased porosity) for the purpose of improving the heat insulating property, a problem of reduction in strength occurs. Therefore, in general, in order to form a pore portion, zirconia is melted in advance and hollow lightweight aggregate is used as one of the raw materials.
【０００３】[0003]
【発明が解決しようとする課題】この軽量骨材は一般的
には粒径が５〜０.１ｍｍであるため耐火物の原料の内
では粗、中粒としての挙動を示す。そのため微粉部分に
比べて焼成過程で焼結収縮し難く、また、熱膨張率も大
きいため、配合量を多くすると耐火物の組織を弱める傾
向が顕著であった。Since this lightweight aggregate generally has a particle size of 5 to 0.1 mm, it exhibits a coarse or medium behavior among the refractory raw materials. Therefore, sintering shrinkage is less likely in the firing process than in the fine powder portion, and the coefficient of thermal expansion is large. Therefore, when the content is increased, the refractory structure tends to be weakened.
【０００４】一方、軽量骨材を使用しない方法として製
造時の乾燥あるいは焼成工程において燃えて無くなる消
失型の気孔形成材(以下、単に「気孔形成材」という)を
適用することも可能であるが(特願平５−112880号)、こ
の方法は粗粒を除外しているため微粉構成に過ぎ、焼成
による収縮が大きくなる。そのため小さな形状のもの例
えば断熱性が要求される小型部品や電子部品またはタイ
ル焼成用セッターのような小形薄板状のものは製造でき
るが、工業炉炉壁のような厚みのある大型形状の耐火物
を製造するのには限界がある。また、品質においては高
温に長時間あるいは繰り返し曝されることにより焼結が
進行するため製品の弾性率が高くなり、耐熱衝撃性が低
下する傾向がある。[0004] On the other hand, as a method without using lightweight aggregates, it is also possible to apply a vanishing type pore-forming material (hereinafter simply referred to as "pore-forming material") which burns and disappears in a drying or firing step during production. (Japanese Patent Application No. 5-112880), since this method excludes coarse particles, it is only a fine powder structure, and the shrinkage due to firing becomes large. For this reason, it is possible to manufacture small-sized refractories such as small parts such as small parts or electronic parts that require heat insulation or tile setters for tile firing, but thick, large-sized refractories like industrial furnace walls. There are limits to manufacturing Further, in terms of quality, sintering proceeds due to prolonged or repeated exposure to high temperatures, so that the elastic modulus of the product tends to increase, and the thermal shock resistance tends to decrease.
【０００５】従って、本発明の目的は、１２００〜２２
００℃といった高温から超高温域で使用される高温工業
炉などの断熱質構造に好適な断熱用ジルコニア質耐火物
の製造方法を提供することにある。Accordingly, an object of the present invention is to provide
00 thermal insulation quality suitable for thermal insulation zirconia refractory structure, such as a high-temperature industrial furnaces used in the ultra-high temperature range from high temperature of ℃
It is to provide a manufacturing method of.
【０００６】[0006]
【０００７】[0007]
【課題を解決するための手段】従って、本発明の断熱用
ジルコニア質耐火物の製造方法は、０．１〜５．０ｍｍ
の粒径を有するジルコニア質軽量骨材と、０．１〜５．
０ｍｍの粒径を有する気孔形成材をジルコニア質軽量骨
材／気孔形成材体積比１／１〜８／１の割合で配合して
なる混合物２０〜４０重量％及び０．５ｍｍ未満の粒径
を有するジルコニア微粉６０〜８０重量％を含有してな
る原料混合物１００重量部に、外掛で１〜１０重量部の
バインダーを添加、混練後、所定の形状に成形し、乾
燥、焼成することにより前記気孔形成材を消失させて
０．１〜５．０ｍｍの気孔を形成させ、且つ全気孔率が
３０〜６０％の範囲内にあることを特徴とする。Accordingly, the method for producing a zirconia refractory for thermal insulation according to the present invention is 0.1 to 5.0 mm.
And a zirconia-based lightweight aggregate having a particle size of 0.1 to 5.
20 to 40% by weight of a mixture obtained by mixing a pore-forming material having a particle size of 0 mm with a zirconia lightweight aggregate / pore-forming material volume ratio of 1/1 to 8/1, and a particle size of less than 0.5 mm 1 to 10 parts by weight of a binder is added to 100 parts by weight of a raw material mixture containing 60 to 80% by weight of zirconia fine powder having a porosity, and the mixture is kneaded, molded into a predetermined shape, dried and fired to form the pores. It is characterized in that pores of 0.1 to 5.0 mm are formed by eliminating the forming material, and the total porosity is in the range of 30 to 60%.
【０００８】[0008]
【作用】本発明者らは、断熱用ジルコニア質耐火物とし
て高い強度を維持しつつ、高い気孔率を得るためには、
通常の耐火物の粗粒、中粒に相当する骨材として中空粒
あるいは多孔質のジルコニア質軽量骨材を使用し、更に
気孔を増すための気孔形成材を組み合わせて使用するこ
とにおいて、その比率と量の範囲を限定することによ
り、容積安定性に優れた良好な組織を得ることができる
ことを見出した。The present inventors have found that in order to obtain high porosity while maintaining high strength as a zirconia refractory for heat insulation,
In the case of using hollow particles or porous zirconia lightweight aggregate as aggregates equivalent to coarse particles and medium particles of ordinary refractories, and further using a pore-forming material to increase pores in combination, By limiting the range of the amount and the amount, it was found that a good structure having excellent volume stability can be obtained.
【０００９】中空粒や多孔質のジルコニア質軽量骨材は
それ自身、焼結による収縮が小さいか、ほとんど収縮し
ないものであるため成形体の容積安定性の維持に効果が
あり、一方、０.１〜５.０ｍｍの粒径を有する気孔形成
材は、０.１〜５.０ｍｍの粒径を有するジルコニア質軽
量骨材で生成させ得る気孔に対し更に気孔量を更に増加
することができる。本発明の断熱用ジルコニア質耐火物
では、このように５.０〜１.０ｍｍの大気孔をジルコニ
ア質軽量骨材と気孔形成材により構成する。この時、成
形体の容積安定性及び強度を維持するためには両者の体
積混合比率は１：１〜８：１であり、これらの混合物の
配合量は全原料の２０〜４０重量％でなければならな
い。また、残部は０.５ｍｍ未満のジルコニア微粉で構
成されており、断熱用ジルコニア質耐火物の全気孔率は
３０〜６０％、好ましくは３５〜５５％の範囲内にあ
る。Hollow grains and porous zirconia-based lightweight aggregates themselves have little or no shrinkage due to sintering, and therefore are effective in maintaining the volume stability of the molded body. The pore-forming material having a particle size of 1 to 5.0 mm can further increase the amount of pores with respect to the pores that can be generated by the zirconia lightweight aggregate having a particle size of 0.1 to 5.0 mm. In the zirconia-based refractory for thermal insulation of the present invention, the air holes having a diameter of 5.0 to 1.0 mm are constituted by the zirconia-based lightweight aggregate and the pore-forming material. At this time, in order to maintain the volume stability and strength of the molded body, the volume mixing ratio of both is 1: 1 to 8: 1, and the blending amount of these mixtures must be 20 to 40% by weight of the whole raw materials. Must. The remainder is composed of zirconia fine powder of less than 0.5 mm, and the total porosity of the zirconia refractory for heat insulation is in the range of 30 to 60%, preferably 35 to 55%.
【００１０】ジルコニア質軽量骨材としては１８００℃
程度の再加熱を受けた時に収縮が小さく、容積の安定し
た中空粒及び／または多孔質骨材を用いる。この中空粒
は、例えばＺｒＯ2を高温で溶融し泡状にして吹き飛ば
し急冷して製造したものがあり、また、多孔質骨材には
ＺｒＯ2粉末を適当な大きさのクリンカーに成形し比較
的低い温度で焼結させたもの、即ち、やや焼結不足な状
態のものを所定の粒度に粉砕したものがある。これらの
ジルコニア質軽量骨材の代わりに通常密度の粗粒を使用
した場合、気孔率を上げられないこと、また、繰り返し
加熱を受けた時に膨張脆化するために好ましくない。1800 ° C. for a zirconia lightweight aggregate
Use hollow particles and / or porous aggregates that have a small volume and a stable volume when subjected to a degree of reheating. These hollow particles are produced by, for example, melting ZrO 2 at a high temperature, blowing it out into a foam, blowing it out, and quenching it. In addition, for porous aggregates, ZrO 2 powder is formed into clinker of an appropriate size and relatively formed. There is a material sintered at a low temperature, that is, a material that is slightly under-sintered and crushed to a predetermined particle size. Use of coarse particles of normal density in place of these zirconia-based lightweight aggregates is not preferable because the porosity cannot be increased, and expansion embrittlement occurs when repeatedly heated.
【００１１】ジルコニア質軽量骨材には９００〜１１０
０℃付近のモノクリニック結晶からテトラゴナル結晶へ
の転移に伴う異常膨張収縮を抑制するために安定化ジル
コニアを使用する。安定化ジルコニアはカルシア、マグ
ネシア、イットリア等により安定化させたもので、安定
化率は３０％以上必要であり、多数回の繰り返し加熱冷
却を受けた場合の組織の安定性から７０〜１００％が好
ましい。安定化率が３０％未満であるとヒステリシスな
熱膨張、収縮により組織を破壊脆化させ、繰り返し熱処
理を受けた場合更にその影響は大きくなる。微粉部分も
同様にジルコニアを安定化するが、安定化剤は配合時に
混合し、焼成過程において安定化しても、あるいは予め
添加溶融または焼成して安定化した原料を用いても良
い。安定化率は骨材と同様に３０％以上あれば良いが、
７０〜１００％が好ましい。また、安定化剤の種類は高
温での安定性からカルシアまたはイットリアが好まし
い。[0011] 900-110 for zirconia lightweight aggregate
Stabilized zirconia is used to suppress abnormal expansion and contraction accompanying the transition from a monoclinic crystal to a tetragonal crystal at around 0 ° C. Stabilized zirconia is stabilized by calcia, magnesia, yttria, etc., and requires a stabilization rate of 30% or more. Due to the stability of the structure when subjected to repeated heating and cooling many times, 70 to 100% is obtained. preferable. If the stabilization rate is less than 30%, the structure is broken and embrittled by hysteretic thermal expansion and shrinkage, and the effect is further increased when repeatedly subjected to heat treatment. The fine powder portion also stabilizes zirconia, but the stabilizer may be mixed at the time of compounding and stabilized during the firing process, or a raw material that has been stabilized by previously adding or melting or firing may be used. The stabilization rate should be 30% or more like aggregate,
70-100% is preferred. The type of stabilizer is preferably calcia or yttria from the viewpoint of stability at high temperatures.
【００１２】ところで粗粒、中粒部として働くジルコニ
ア質軽量骨材と微粉部分とは組織の安定のために熱膨張
率の差の小さい方が良く、従って、ジルコニア質軽量骨
材も微粉部に近いものを微粉部の構成により選択する必
要があり、安定化剤の成分も同じ方が好ましい。By the way, it is better that the difference in coefficient of thermal expansion between the zirconia-based lightweight aggregate serving as the coarse and medium grain portions and the fine powder portion is small in order to stabilize the structure. Therefore, the zirconia-based lightweight aggregate is also included in the fine powder portion. It is necessary to select a close one according to the configuration of the fine powder part, and the same component is preferable for the stabilizer.
【００１３】気孔形成材は、乾燥工程あるいは焼成工程
において燃えて無くなるものであればどんな材質でも良
いが、成形時に加圧により縮み、放圧により再び膨らむ
ものは成形亀裂の原因となるため不適当である。一般的
には有機質である樹脂や木質材料等を使用することがで
き、例えば樹脂ではエチレンビニルアルコール、ポリプ
ロピレン等のプラスチックが、また、木質材料では胡
桃、桃の殻といった堅い材料が適当である。The pore-forming material may be any material as long as it can be burned off in the drying step or the firing step, but any material which shrinks by pressurization during molding and expands again by releasing pressure is unsuitable because it causes molding cracks. It is. In general, organic resins and wood materials can be used. For example, plastics such as ethylene vinyl alcohol and polypropylene are suitable for resins, and hard materials such as walnut and peach shell are suitable for wood materials.
【００１４】上記ジルコニア質軽量骨材と気孔形成材は
粒径が０.１〜５.０ｍｍの範囲内でなくてはならず、好
ましくは０.３〜３.０ｍｍで、特に気孔形成材は０.５
〜１ｍｍであることが好ましい。粒径が０.１ｍｍより
小さくなると練り土の嵩が大きくなり、亀裂の発生等に
より成形が困難となることや、焼成時に気孔が焼結によ
り消失してしまう恐れがあるためである。ジルコニア質
軽量骨材は、粒径が５ｍｍを超えると焼成過程において
微粉部との収縮差によりな馴染みが悪くなり、強度が低
下する。また、気孔形成材の粒径が５ｍｍを超えると焼
成工程において、収縮が大きくなり内部歪が発生するた
め変形、亀裂等を招き組織、容積の安定性が悪く強度も
低下する。The zirconia-based lightweight aggregate and the pore-forming material must have a particle size within a range of 0.1 to 5.0 mm, preferably 0.3 to 3.0 mm, and particularly preferably a pore-forming material. 0.5
It is preferably about 1 mm. If the particle size is smaller than 0.1 mm, the bulk of the kneaded soil becomes large, making it difficult to form due to cracks and the like, and pores may be lost by sintering during firing. When the particle diameter of the zirconia-based lightweight aggregate exceeds 5 mm, familiarity is deteriorated due to a difference in shrinkage from a fine powder portion in a firing process, and strength is reduced. On the other hand, if the particle size of the pore-forming material exceeds 5 mm, the shrinkage becomes large and internal strain is generated in the firing step.
【００１５】ジルコニア質軽量骨材と気孔形成材の比率
は体積比率で１：１〜８：１の範囲内にある必要があ
り、できれば２：１〜７：１が好ましい。比率が１：１
より小さいと焼成時の収縮が大きくなり、焼成時の変形
や小亀裂の発生がある。また、８：１より大きくなると
再び加熱を受けた時に軽量骨材の熱膨張が大きいため微
粉で構成されるマトリックス組織を破壊し、強度低下す
る傾向がでる。The ratio of the zirconia-based lightweight aggregate to the pore-forming material must be in the range of 1: 1 to 8: 1 by volume, preferably 2: 1 to 7: 1. 1: 1 ratio
If it is smaller, shrinkage at the time of firing becomes large, and deformation and small cracks occur at the time of firing. On the other hand, when the ratio is larger than 8: 1, when the material is heated again, the thermal expansion of the lightweight aggregate is large, so that the matrix structure composed of fine powder is broken, and the strength tends to decrease.
【００１６】このようにジルコニア質軽量骨材と気孔形
成材の比率を一定範囲内にした混合物の配合量が全体に
対し２０〜４０重量％、好ましくは２５〜３５重量％で
あるようにする必要がある。この理由は全配合量に対し
軽量骨材と気孔形成材の合計量が２０重量％より少ない
と気孔量が少なく充分な断熱性が得られないためであ
り、４０重量％より多いとジルコニア質軽量骨材同士を
結合するマトリックスとなる微粉部が量的に不足するた
めである。Thus, it is necessary that the blending amount of the mixture in which the ratio of the zirconia-based lightweight aggregate to the pore-forming material is within a certain range is 20 to 40% by weight, preferably 25 to 35% by weight. There is. The reason for this is that if the total amount of the lightweight aggregate and the pore-forming material is less than 20% by weight with respect to the total blending amount, the amount of pores is so small that sufficient heat insulating properties cannot be obtained. This is because the amount of the fine powder portion serving as a matrix for bonding the aggregates is insufficient.
【００１７】気孔形成用、即ち、ジルコニア質軽量骨材
以外のジルコニア原料は粒径０.５ｍｍ以下の微粉であ
る必要があり、特に、０.０４４ｍｍ以下の微粉原料を
４割以上配合することが好ましい。０.５ｍｍより大き
い粒径を多く含むと焼結性が良くないためジルコニア質
軽量骨材同士を結合するマトリックスとして有効に働か
ない。The zirconia raw material for forming pores, that is, other than the zirconia-based light-weight aggregate, must be fine powder having a particle size of 0.5 mm or less. In particular, 40% or more of the fine powder raw material having a particle size of 0.044 mm or less must be blended. preferable. If the particle size is larger than 0.5 mm, the sinterability is not good, so that the zirconia lightweight aggregate does not work effectively as a matrix.
【００１８】以上の条件により原料を秤量し、フェノー
ル樹脂、ＣＭＣ水溶液、リグニンスルフォン酸ソーダ等
の通常のバインダーをジルコニア質軽量骨材、気孔形成
材及びジルコニア原料の合計量に対して外掛で１〜１０
重量％、好ましくは１.５〜８重量％添加し、混練後、
１０ＭＰａ以上、好ましくは２０〜５０ＭＰａの成形圧
力にて所定の形状に成形し、８０〜１５０℃、好ましく
は１００〜１２０℃の温度で５〜３０時間、好ましくは
１０〜２４時間にわたり乾燥し、次に、大気中１６００
〜１９００℃、好ましくは１７００〜１８５０℃、最
適には１７００℃の温度で２〜６時間、好ましくは３〜
５時間で焼成する。Under the above conditions, the raw materials are weighed, and a normal binder such as a phenol resin, a CMC aqueous solution, and sodium lignin sulfonate is externally added to the total amount of the zirconia-based lightweight aggregate, the pore-forming material, and the zirconia raw material by one to one. 10
%, Preferably 1.5 to 8% by weight, and after kneading,
10 MPa or more, preferably molded into a predetermined shape at a molding pressure of 20 to 50 MPa, dried at a temperature of 80 to 150 ℃, preferably 100 to 120 ℃ for 5 to 30 hours, preferably 10 to 24 hours, 1600 in the atmosphere
~ 1900C, preferably 1700-1850C, optimally 1700C for 2-6 hours, preferably 3 ~
Bake for 5 hours.
【００１９】上述のような原料配合を有する原料混合物
より得られた断熱用ジルコニア質耐火物は、全気孔率が
３０〜６０％の範囲内にあり、断熱性に優れ、強度も充
分なものとなる。なお、全気孔率が３０％に達しないも
のは断熱性に劣り、６０％を超えると強度が不足し、繰
り返しての使用には耐えない。The zirconia refractory for heat insulation obtained from the raw material mixture having the above-mentioned raw material blend has a total porosity in the range of 30 to 60%, and has excellent heat insulating properties and sufficient strength. Become. If the total porosity does not reach 30%, the heat insulating property is inferior, and if it exceeds 60%, the strength is insufficient, and it cannot withstand repeated use.
【００２０】[0020]
実施例１ ０.１〜５ｍｍの粒径を有するジルコニア質軽量骨材と
して安定化率が８０％のカルシア安定化ジルコニア中空
粒を、また、０.１〜５ｍｍの粒径を有する気孔形成材
としてポリプロピレンを使用し、微粉部分には安定化率
が８０％のカルシア安定化ジルコニアを使用して断熱用
ジルコニア質耐火物を製作した。原料の粒度配合を表１
に示す。まず、所定量のジルコニア質軽量骨材と気孔形
成材を混合し、得られた混合物に更にカルシア安定化ジ
ルコニア微粉を添加し、次に、これら原料混合物に対し
バインダーとしてフェノール樹脂を外掛４重量％添加
し、混練した後、一軸プレスにて成形圧約３０ＭＰａで
２３０×１１４×６５ｍｍの形状に成形した。これを２
００℃で２０時間乾燥した後、大気中約１７５０℃で５
時間焼成し、目的とする断熱用ジルコニア質耐火物を得
た。Example 1 As a zirconia-based lightweight aggregate having a particle size of 0.1 to 5 mm, calcia-stabilized zirconia hollow particles having a stabilization rate of 80% and a pore-forming material having a particle size of 0.1 to 5 mm were used. A zirconia refractory for thermal insulation was produced using polypropylene and calcia-stabilized zirconia having a stabilization ratio of 80% in the fine powder portion. Table 1 shows the particle size composition of the raw materials.
Shown in First, a predetermined amount of a zirconia-based lightweight aggregate and a pore-forming material are mixed, and calcia-stabilized zirconia fine powder is further added to the obtained mixture. After adding and kneading, the mixture was formed into a shape of 230 × 114 × 65 mm by a uniaxial press at a forming pressure of about 30 MPa. This is 2
After drying at 00 ° C for 20 hours, it is dried in air at about 1750 ° C for 5 hours.
Firing was performed for a period of time to obtain a desired zirconia refractory for heat insulation.
【００２１】これらの断熱用ジルコニア質耐火物につい
て１５００℃で１００時間の再加熱試験をした。試験前
後の物性値、曲げ強度、安定化率及び線変化率(残存膨
張率)を測定し、組織の脆化及び容積の安定性を評価し
た。These refractory zirconia refractories for heat insulation were subjected to a reheating test at 1500 ° C. for 100 hours. Physical property values before and after the test, bending strength, stabilization rate, and linear change rate (residual expansion rate) were measured to evaluate the embrittlement of the structure and the stability of the volume.
【００２２】[0022]
【表１】 [Table 1]
【００２３】なお、安定性率(ｘ)は粉末Ｘ線回折による
Ｘ線チャートの２θ＝２７〜３３°に測定されるピーク
高さを用いて次式により求めた。The stability rate (x) was determined by the following equation using the peak height measured at 2θ = 27 to 33 ° in the X-ray chart by powder X-ray diffraction.
【００２４】[0024]
【数１】 (Equation 1)
【００２５】式中、Ｉcは立方晶ジルコニアのピーク高
さを表し、Ｉmは単斜晶ジルコニアのピーク高さをそれ
ぞれ表す。[0025] In the formula, I c represents the peak height of the cubic zirconia, I m represents respectively a peak height of monoclinic zirconia.
【００２６】試験の結果を表１に示す。表１からジルコ
ニア質軽量骨材／気孔形成材の体積混合比率が１より小
さい比較品１は焼成線変化率が負に大となり容積の安定
性が保たれない。また、比率が８よりも大きい比較品５
は再加熱試験後の線変化率が正に大となり強度の低下が
大きく組織脆化が大きいことが分かる。The results of the test are shown in Table 1. From Table 1, Comparative Example 1 in which the volume mixing ratio of zirconia-based lightweight aggregate / pore-forming material is smaller than 1 has a large negative firing line change rate, and the volume stability cannot be maintained. Comparative product 5 having a ratio larger than 8
It can be seen that the linear change rate after the reheating test was positive, the strength was greatly reduced, and the structure was brittle.
【００２７】ジルコニア質軽量骨材／気孔形成材の混合
物の配合量が２０重量％未満である比較品２は焼成収縮
が大きく造りづらい割に気孔率が３０％を超えず、熱伝
導率が高いため現実的でない。配合量が４０重量％を超
える比較品３は強度が低い。また、再加熱後の線変化率
も正に大きく良くならない。The comparative product 2 containing less than 20% by weight of the mixture of the zirconia-based lightweight aggregate and the pore-forming material has a large porosity, does not exceed 30%, and has a high thermal conductivity, though the firing shrinkage is large and it is difficult to produce. It is not realistic. Comparative product 3 in which the amount exceeds 40% by weight has low strength. In addition, the linear change rate after reheating is not so large and improved.
【００２８】微粉部分に粒径２〜０.５ｍｍのカルシア
安定化ジルコニアを配合した比較品４は焼結性が悪く、
低強度となり、再加熱後の線変化率も正に大きくなる。Comparative product 4 in which calcia-stabilized zirconia having a particle size of 2 to 0.5 mm was blended in the fine powder portion had poor sinterability.
The strength becomes low, and the linear change rate after reheating also becomes positive.
【００２９】[0029]
【発明の効果】本発明の断熱質ジルコニア耐火物は、中
空状または多孔質のジルコニア質軽量骨材と共に焼成時
に燃えて無くなる気孔形成材を適正な体積混合比で組み
合わせることにより大型の製品においても目的とする気
孔率を得、高い断熱性を獲得したものである。この材質
は従来のアルミナ質等の耐火断熱材料では耐用が困難で
あった１２００〜２２００℃といった高温から超高温域
で使用される高温工業炉などの断熱質構造に好適な耐火
物を提供する。The heat-insulating zirconia refractory of the present invention can be used for large-sized products by combining a hollow or porous zirconia lightweight aggregate with a pore-forming material which does not burn during firing at an appropriate volume mixing ratio. It has the desired porosity and high heat insulation. This material provides a refractory suitable for a heat insulating structure such as a high-temperature industrial furnace used in a high temperature range of 1200 to 2200 ° C. to an ultra-high temperature range, which has been difficult to use with a conventional refractory heat insulating material such as alumina.
Claims (1)
コニア質軽量骨材と、０．１〜５．０ｍｍの粒径を有す
る気孔形成材をジルコニア質軽量骨材／気孔形成材体積
比１／１〜８／１の割合で配合してなる混合物２０〜４
０重量％及び０．５ｍｍ未満の粒径を有するジルコニア
微粉６０〜８０重量％を含有してなる原料混合物１００
重量部に、外掛で１〜１０重量部のバインダーを添加、
混練後、所定の形状に成形し、乾燥、焼成することによ
り前記気孔形成材を消失させて０．１〜５．０ｍｍの気
孔を形成させ、且つ全気孔率が３０〜６０％の範囲内に
あることを特徴とする断熱用ジルコニア質耐火物の製造
方法。1. A lightweight zirconia aggregate having a particle size of 0.1 to 5.0 mm and a pore-forming material having a particle size of 0.1 to 5.0 mm are combined with a zirconia lightweight aggregate / pore-forming material volume. Mixtures 20 to 4 blended at a ratio of 1/1 to 8/1
Raw material mixture 100 comprising 0% by weight and 60-80% by weight of zirconia fine powder having a particle size of less than 0.5 mm
1 to 10 parts by weight of binder are added to parts by weight,
After kneading, the mixture is molded into a predetermined shape, dried and fired to eliminate the pore-forming material to form pores of 0.1 to 5.0 mm, and the total porosity is in the range of 30 to 60%. A method for producing a zirconia-based refractory for thermal insulation, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06135779A JP3103480B2 (en) | 1994-06-17 | 1994-06-17 | Method for producing zirconia refractory for thermal insulation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06135779A JP3103480B2 (en) | 1994-06-17 | 1994-06-17 | Method for producing zirconia refractory for thermal insulation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH082980A JPH082980A (en) | 1996-01-09 |
| JP3103480B2 true JP3103480B2 (en) | 2000-10-30 |
Family
ID=15159664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06135779A Expired - Fee Related JP3103480B2 (en) | 1994-06-17 | 1994-06-17 | Method for producing zirconia refractory for thermal insulation |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3103480B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8278231B2 (en) * | 2008-11-24 | 2012-10-02 | Exxonmobil Chemical Patents Inc. | Heat stable formed ceramic, apparatus and method of using the same |
| JP6431252B2 (en) * | 2012-09-28 | 2018-11-28 | 黒崎播磨株式会社 | Insulating material and manufacturing method thereof |
| JP6127353B2 (en) * | 2015-03-16 | 2017-05-17 | ニチアス株式会社 | Insulating material and manufacturing method thereof |
| WO2016147665A1 (en) * | 2015-03-16 | 2016-09-22 | ニチアス株式会社 | Heat insulator and method for producing same |
| CN108947568B (en) * | 2018-08-16 | 2021-03-23 | 中钢集团洛阳耐火材料研究院有限公司 | Method for preparing alumina hollow ball brick by using pore-forming agent |
-
1994
- 1994-06-17 JP JP06135779A patent/JP3103480B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH082980A (en) | 1996-01-09 |
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