JPH09142917A - Production of calcined magnesia-spinel brick - Google Patents
Production of calcined magnesia-spinel brickInfo
- Publication number
- JPH09142917A JPH09142917A JP7319561A JP31956195A JPH09142917A JP H09142917 A JPH09142917 A JP H09142917A JP 7319561 A JP7319561 A JP 7319561A JP 31956195 A JP31956195 A JP 31956195A JP H09142917 A JPH09142917 A JP H09142917A
- Authority
- JP
- Japan
- Prior art keywords
- spinel
- magnesia
- brick
- clinker
- mgo
- 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.)
- Pending
Links
- 239000011029 spinel Substances 0.000 title claims abstract description 56
- 229910052596 spinel Inorganic materials 0.000 title claims abstract description 56
- 239000011449 brick Substances 0.000 title claims abstract description 33
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000000843 powder Substances 0.000 claims abstract description 6
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 77
- 239000000395 magnesium oxide Substances 0.000 claims description 39
- 238000010304 firing Methods 0.000 claims description 20
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 11
- 239000002994 raw material Substances 0.000 claims description 5
- 238000000034 method Methods 0.000 abstract description 6
- 239000002245 particle Substances 0.000 abstract description 6
- 239000011159 matrix material Substances 0.000 abstract description 5
- 230000003247 decreasing effect Effects 0.000 abstract description 2
- 229910052751 metal Inorganic materials 0.000 abstract description 2
- 239000002184 metal Substances 0.000 abstract description 2
- 229910018404 Al2 O3 Inorganic materials 0.000 abstract 3
- 230000000630 rising effect Effects 0.000 abstract 1
- 238000004901 spalling Methods 0.000 abstract 1
- 235000012245 magnesium oxide Nutrition 0.000 description 36
- 230000029087 digestion Effects 0.000 description 23
- 230000000052 comparative effect Effects 0.000 description 11
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 9
- 238000001816 cooling Methods 0.000 description 7
- 239000006104 solid solution Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 239000004568 cement Substances 0.000 description 3
- 238000004453 electron probe microanalysis Methods 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000001079 digestive effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 238000007561 laser diffraction method Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- 238000000790 scattering method Methods 0.000 description 1
- 229910052566 spinel group Inorganic materials 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、溶融金属容器やセ
メントロータリーキルンの内張りれんがとして好適に使
用できる焼成マグネシア・スピネルれんがに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fired magnesia spinel brick which can be suitably used as a lining brick for a molten metal container or a cement rotary kiln.
【０００２】[0002]
【従来の技術】焼成マグネシア・スピネルれんが中のス
ピネルの機能については、例えば特開平４−３３８１６
１号公報に記載されている。これによると、耐火性骨材
に添加された金属鉄粉末が、まず液相として焼結に寄与
した後、酸化されてＦｅ2Ｏ3となり、これが、組織中に
均一に分散固溶することにより、マトリックス部のスピ
ネル結合が発達する。この際、金属鉄粉末が酸化される
時に酸素を消費して、雰囲気を還元状態にすることも焼
結に寄与するとされている。また、Ａｌ2Ｏ3超微粉も同
様に組織中に均一に分散固溶することにより、マトリッ
クス部のスピネル結合が飛躍的に発達し、そのために高
い熱間強度を得るとしている。2. Description of the Related Art The function of spinel in a fired magnesia spinel brick is described, for example, in JP-A-4-33816.
No. 1 publication. According to this, the metallic iron powder added to the refractory aggregate first contributes to sintering as a liquid phase and is then oxidized to Fe 2 O 3 , which is uniformly dispersed and solid-dissolved in the structure. , The spinel bond of the matrix part develops. At this time, it is said that consuming oxygen when the metallic iron powder is oxidized to bring the atmosphere into a reduced state also contributes to the sintering. In addition, it is said that the ultrafine Al 2 O 3 powder is also uniformly dispersed and solid-dissolved in the structure, whereby spinel bonds in the matrix portion are dramatically developed, and therefore high hot strength is obtained.
【０００３】また、「スピネルれんがの使用実績」第１
５回高温材料シンポジウム、社団法人窯業協会高温材料
部会（１９７９年１２月７日）ｐ．２８〜３７において
は、マグネシアクリンカーとスピネルクリンカーとを配
合、混合し、成形した後焼成したものはペリクレース格
子定数、スピネル格子定数ともいずれも変化し、ペリク
レース中へのアルミナの固溶が生じているとしている。In addition, "Use record of spinel brick" No. 1
5th High Temperature Materials Symposium, Ceramic Industry Association High Temperature Materials Subcommittee (December 7, 1979) p. In Nos. 28 to 37, the magnesia clinker and the spinel clinker were mixed, mixed, molded, and fired, and both the periclase lattice constant and the spinel lattice constant changed, and solid solution of alumina occurred in the periclase. I am trying.
【０００４】このように、１７００°Ｃ〜１８００°Ｃ
という超高温にて焼成することにより粒界の結合力を高
めることが可能であり、酸化鉄あるいは超微粉アルミナ
の添加によって、それよりも低い温度での焼成中に粒間
でスピネルが形成し熱間強度が改善される。In this way, 1700 ° C to 1800 ° C
It is possible to increase the bond strength of grain boundaries by firing at an ultrahigh temperature, and by adding iron oxide or ultrafine alumina, spinels are formed between grains during firing at a lower temperature and Strength is improved.
【０００５】この熱間強度に優れたスピネル質れんがの
用途の一つとして、従来から、セメントロータリーキル
ンの焼成帯にマグネシア・クロム・ダイレクトボンドれ
んが（マグクロダイレクトボンドれんがと称される）
や、マグシネア・スピネルれんが（マグスピネルれんが
と称される）が使用条件に応じてゾーンライニングされ
ている。As one of the uses of this spinel brick having excellent hot strength, conventionally, magnesia-chromium direct-bond brick (called magcro direct-bond brick) is used in the firing zone of a cement rotary kiln.
Also, Magcinea spinel bricks (called Magspinel bricks) are zone-lined according to the conditions of use.
【０００６】この中、マグクロダイレクトボンドれんが
は、れんが中に６価クロムを含有しており、そのため、
公害発生源となる可能性があり、マグクロダイレクトボ
ンドれんがに代えて、マグスピネルれんがの使用範囲が
拡大される傾向にある。このマグスピネルれんがは、耐
スポール性に優れ、且つ熱変化に対する体積安定性にも
優れてはいるが、熱間強度が低く、耐磨耗性に劣るため
使用部位に制約を受け、また、マグネシアを原料として
いるため、長期保存中には消化によるキレツが生じるな
どの欠点がある。Among these, magcro direct bond bricks contain hexavalent chromium in the bricks, and therefore,
It is a potential source of pollution and tends to expand the range of use of mag spinel bricks instead of magcro direct bond bricks. This mag spinel brick has excellent spall resistance and volume stability against heat changes, but its hot strength is low and its wear resistance is inferior. Since it is used as a raw material, it has drawbacks such as cracking due to digestion during long-term storage.
【０００７】この欠点の中、熱間強度を高める方法とし
ては、特開平４−３３８１６１号公報において、ＭｇＯ
クリンカー５０〜９５重量％とＭｇＯ−Ａｌ2Ｏ3スピネ
ルクリンカー５〜５０重量％とからなる耐火性骨材に対
して、粒度が４４μｍ以下の金属鉄粉末を外重量で１〜
４重量％、あるいは、粒度が１０μｍ以下のＡｌ2Ｏ3の
超微粉を外掛で１〜５重量％添加することによって、マ
トリックス部でのスピネル結合を発達させて熱間強度と
耐スポール性を改善することが開示されている。Among these drawbacks, as a method for increasing the hot strength, there is disclosed in JP-A-4-338161, MgO.
For a refractory aggregate composed of 50 to 95% by weight of clinker and 5 to 50% by weight of MgO—Al 2 O 3 spinel clinker, 1 to 3 weight percent of metallic iron powder having a particle size of 44 μm or less is externally added.
By adding 4% by weight or 1 to 5% by weight of Al 2 O 3 ultrafine powder having a particle size of 10 μm or less to the outside, spinel bonding is developed in the matrix part to improve hot strength and spall resistance. Is disclosed.
【０００８】しかしながら、この種のマグネシアを主体
とするれんがでは、耐消化性が問題となり、「スピネル
れんがの使用実績」（第１５回高温材料シンポジウム、
社団法人窯業協会高温材料部会（１９７９年１２月７
日）ｐ．２８〜３７）において、スピネル添加量の増大
と共に耐消化性が悪化することを報告しており、マグネ
シアクリンカーとスピネルクリンカーとの組み合わせで
の焼成が消化と関連がありそうであることを示唆してい
る。However, in this type of magnesia-based brick, the digestion resistance is a problem, and the "use record of spinel brick" (15th High Temperature Material Symposium,
High Temperature Material Subcommittee of Ceramic Industry Association (December 7, 1979)
Day) p. 28-37) that the digestion resistance deteriorates as the amount of spinel added increases, suggesting that firing with a combination of magnesia clinker and spinel clinker is likely to be related to digestion. There is.
【０００９】また、「耐火物」３３［３］Ｐ１２１−１
２７（１９８１）において、アルミナの添加あるいはマ
グネシア−スピネル系クリンカーの場合、マグネシア単
体よりも耐消化性が劣ることを報告している。Also, "Refractory" 33 [3] P121-1
27 (1981), it is reported that the addition of alumina or the magnesia-spinel clinker is inferior in digestion resistance to magnesia alone.
【００１０】[0010]
【発明が解決しようとする課題】本発明において解決し
ようとする課題は、スピネル系れんがにおいて熱間強度
を損なうことなしに耐消化性を向上させることにある。SUMMARY OF THE INVENTION The problem to be solved by the present invention is to improve the digestion resistance of spinel type bricks without impairing the hot strength.
【００１１】[0011]
【課題を解決するための手段】本発明は、ＭｇＯクリン
カー５０〜９５重量％とＭｇＯ−Ａｌ2Ｏ3スピネルクリ
ンカー５〜５０重量％とからなる耐火性骨材に、金属鉄
粉末、あるいは、Ａｌ2Ｏ3超微粉を添加した配合原料を
焼成してマグネシア・スピネルれんがを製造する方法で
あって、１４００〜１７５０°Ｃとし、望ましくは１５
００°Ｃ〜１７００°Ｃの温度範囲で焼成し、かつ降温
速度を５０°Ｃ／ｈｒ以上、望ましくは１００°Ｃ／ｈ
ｒ以上の早い冷却速度で降温することにより耐消化性の
優れたマグネシア・スピネルれんがを得るものである。According to the present invention, a refractory aggregate comprising 50 to 95% by weight of MgO clinker and 5 to 50% by weight of MgO-Al 2 O 3 spinel clinker, metallic iron powder, or Al. A method for producing a magnesia spinel brick by firing a compounded raw material to which 2 O 3 ultrafine powder has been added, which is set to 1400 to 1750 ° C, preferably 15
Firing in the temperature range of 00 ° C to 1700 ° C and cooling rate of 50 ° C / hr or more, preferably 100 ° C / h
By lowering the temperature at a high cooling rate of r or higher, magnesia spinel bricks having excellent digestion resistance can be obtained.
【００１２】[0012]
【発明の実施の形態】本発明は、得られたれんがの微構
造を詳細に観察した結果、生成したスピネル周囲にはマ
イクロクラックが多数生成していることを発見したこと
に基づく。すなわち、マグネシアとアルミナの反応によ
り生成したスピネルあるいはマグネシアクリンカー中に
スピネル中のアルミナ成分が固溶して反応生成したスピ
ネル、いわゆる２次スピネルは、１０°Ｃ〜５０°Ｃ／
ｈｒという通常の焼成条件で降温した場合、焼成中は固
溶していたスピネルが、冷却中にペリクレース中からス
ピネルが析出し、ペリクレースとスピネルとの膨張差
（スピネル７．５×１０-6／°Ｃ、ペリクレース１４．
０×１０-6／°Ｃ）によりスピネル周囲にマイクロクラ
ックが生成し、その結果レンガの比表面積が増大し、消
化が起こり易くなるという知見に基づいて完成した。BEST MODE FOR CARRYING OUT THE INVENTION The present invention is based on the fact that as a result of observing the microstructure of the obtained brick in detail, a large number of microcracks are formed around the formed spinel. That is, spinel produced by the reaction of magnesia and alumina or spinel produced by the solid solution of the alumina component in the spinel in the magnesia clinker, a so-called secondary spinel, is 10 ° C to 50 ° C /
When the temperature is lowered under the normal firing condition of hr, the spinel that is in solid solution during firing is precipitated from the periclase during cooling, and the expansion difference between the periclase and the spinel (spinel 7.5 × 10 −6 / ° C, Pericles 14.
It was completed based on the finding that microcracks were generated around the spinel due to 0 × 10 −6 / ° C.), resulting in an increase in the specific surface area of the brick, which facilitated digestion.
【００１３】これは添加剤のないマグネシア−スピネル
系では使用したマグネシアクリンカー内部でペリクレー
ス粒界に固溶したスピネルが析出し、その周囲にはマイ
クロクラックが発生していることを確認しており、消化
が不良となるメカニズムは同様である。It has been confirmed that in the magnesia-spinel system without additives, spinel which is solid-solved in the periclase grain boundaries is precipitated inside the magnesia clinker used, and microcracks are generated around it. The mechanism of poor digestion is similar.
【００１４】これらの現象は通常の冷却速度条件下での
焼成温度が上昇する程顕著であり、特に１７００°Ｃを
越えた焼成温度で焼成したマグスピネル系れんがの耐消
化性は１７００°Ｃ以下で焼成したものと比べて、著し
く耐消化性に劣る。しかしながら、本発明による製造法
によって、例えば１００°Ｃ／ｈｒ程度の速度で冷却す
ると、ペリクレース中に固溶しているスピネルは完全に
は析出せずに一部はペリクレース中に取り残されてお
り、ペリクレース粒間以外にペリクレース中に１〜２ミ
クロン程度のスピネル粒が存在しているのが認められ
た。またクラック発生状況も、例えば１０°Ｃ／ｈｒで
冷却した通常冷却品と比べてクラックが少なく、その結
果、耐消化性が向上している。These phenomena become more remarkable as the firing temperature rises under the normal cooling rate condition, and particularly, the digestion resistance of the mag spinel type bricks fired at the firing temperature exceeding 1700 ° C is 1700 ° C or less. Digestion resistance is remarkably inferior to that of baked products. However, according to the production method of the present invention, when cooled at a rate of, for example, about 100 ° C./hr, the spinel solid-solved in the periclase is not completely precipitated and a part of the spinel is left behind in the periclase, It was confirmed that spinel grains of about 1 to 2 μm were present in the periclase other than between the periclase grains. Further, the cracks are generated in less number of cracks as compared with a normal cooling product cooled at, for example, 10 ° C./hr, and as a result, digestion resistance is improved.
【００１５】この理由は、Ｊ．Ａｍ．Ｃｅｒａｍ．Ｓｏ
ｃ．，４５［６］２６４ （１９６２）に示されている
ＭｇＯ−ＭｇＯ・Ａｌ2Ｏ3状態図から明らかなように、
ペリクレース中に固溶するＡｌ2Ｏ3の領域があり、１６
００°Ｃ以下ではＡｌ2Ｏ3は固溶せずに生成スピネル形
態は反応時の形態を保持し、ペリクレースとの膨張差に
よる応力は周囲の結合不足のボンドの切断などにより、
大きなクラックを伴わない。逆に１８００°Ｃで焼成し
た場合は相当量のスピネルがペリクレース中に固溶し、
焼成冷却中にペリクレース粒間で析出し、膨張差により
マイクロクラックが発生するということによる。The reason for this is that J. Am. Ceram. So
c. , 45 [6] 264 (1962), the MgO-MgO.Al 2 O 3 phase diagram clearly shows that
There is a region of solid solution Al 2 O 3 in periclase, 16
At less than 00 ° C, Al 2 O 3 does not form a solid solution and the spinel morphology is maintained at the time of reaction, and the stress due to the difference in expansion from the periclase is due to the disconnection of insufficient bonds in the surroundings.
No big cracks. Conversely, when fired at 1800 ° C, a considerable amount of spinel dissolves in the periclase,
This is due to the fact that during firing cooling, precipitation occurs between the periclase grains and microcracks occur due to the difference in expansion.
【００１６】本発明において添加される金属鉄粉末は、
粒度が４４μｍ以下のもので、その添加量は、骨材に対
して１〜４重量％であり、また、Ａｌ2Ｏ3超微粉は、粒
度が１０μｍ以下のものを外重量で１〜５重量％添加さ
れる。The metallic iron powder added in the present invention is
The particle size is 44 μm or less, the addition amount is 1 to 4% by weight with respect to the aggregate, and the Al 2 O 3 ultrafine powder has a particle size of 10 μm or less in an external weight of 1 to 5% by weight. % Is added.
【００１７】[0017]
【実施例】表１、表２及び表５に本発明の実施例と比較
例での配合と物性ならびに消化重量増加率ならびに消化
試験後亀裂状況を示す。EXAMPLES Tables 1, 2 and 5 show the blending and physical properties of Examples and Comparative Examples of the present invention, the rate of increase in digestive weight and the state of cracking after digestion test.
【００１８】実施例及び比較例に使用したマグネシアク
リンカーはＭｇＯ ９９．３％、ＣａＯ ０．４％、Ｓ
ｉＯ2 ０．１７％、Ｂ2Ｏ3 ０．０４％であり、スピ
ネルクリンカーはＭｇＯ ２８．０５％、ＣａＯ ０．
２４％、ＳｉＯ2 ０．１５％、Ａｌ2Ｏ3 ７１．７３
％であり、超微粉アルミナはＮａ2Ｏ3が０．３％以下の
仮焼アルミナを使用した。超微粉アルミナの粒度をレー
ザー回折／散乱法にて測定した結果、重量分布基準５０
％径は２．７ミクロンであった。マグネシアクリンカー
及びスピネルクリンカーを所定配合にて配合し、超微粉
アルミナを３．３ｗｔ％、１０ｗｔ％添加した２配合を
混練・成形した。表１の実施例の場合、昇温速度１００
°Ｃ／ｈｒ，焼成温度１５００°Ｃ、１７００°Ｃと
し、表１の比較例の場合は、焼成温度１３５０°Ｃ、１
８００°Ｃとした。保持時間８時間で焼成し、降温速度
は、表１の実施例及び比較例とも１００°Ｃ／ｈｒと
し、表２の比較例の場合は１０°Ｃ／ｈｒとして、それ
ぞれの降温速度における耐消化性を評価した。The magnesia clinker used in the examples and comparative examples was MgO 99.3%, CaO 0.4%, S.
iO 2 0.17%, B 2 O 3 0.04%, spinel clinker MgO 28.05%, CaO 0.
24%, SiO 2 0.15%, Al 2 O 3 71.73
%, And the ultrafine alumina used was calcined alumina containing 0.3% or less of Na 2 O 3 . The particle size of ultrafine alumina was measured by the laser diffraction / scattering method, and the weight distribution standard was 50.
The% diameter was 2.7 microns. Magnesia clinker and spinel clinker were compounded in a predetermined composition, and 2 compounds containing 3.3 wt% and 10 wt% of ultrafine alumina were kneaded and molded. In the case of the examples in Table 1, the heating rate is 100
° C / hr, firing temperature 1500 ° C, 1700 ° C. In the case of the comparative example of Table 1, firing temperature 1350 ° C, 1
It was set to 800 ° C. It was fired at a holding time of 8 hours, and the temperature lowering rate was 100 ° C./hr for both the examples and comparative examples in Table 1, and 10 ° C./hr for the comparative example in Table 2, and the digestion resistance at each temperature lowering rate was set. The sex was evaluated.
【００１９】また、耐消化性評価方法は、”菅原 光
男、飯塚 祥治、原田 正博、「熱水を用いたマグネシ
アの耐消化性試験」ｐ．８１−９０、耐火物技術協会、
第５５回原料専門委員会（１９９５年９月６日）”にお
ける熱水法を採用した。試験条件はサンプル形状は２０
×２０×約３５ｍｍのサイズで、消化試験は熱水温度８
０°Ｃ、浸漬時間を４８時間と実施した。The digestion resistance evaluation method is described in "Mitsuo Sugawara, Shoji Iizuka, Masahiro Harada," Digestion resistance test of magnesia using hot water "p. 81-90, Refractory Technology Association,
The 55th Raw Material Special Committee (September 6, 1995) "was used as the hydrothermal method. The test conditions were 20 for the sample shape.
The size of x 20 x about 35 mm, the digestion test is hot water temperature 8
The immersion was performed at 0 ° C for 48 hours.
【００２０】実施例１〜４と比較例５〜１２では，降温
速度による耐消化性の差異が現れ、実施例は、比較例と
対比して耐消化性において優れているという結果となっ
た。In Examples 1 to 4 and Comparative Examples 5 to 12, the difference in the digestion resistance depending on the temperature lowering rate appeared, and the result was that the Example was superior in the digestion resistance as compared with the Comparative Example.
【００２１】図１と図２に、それぞれ実施例２と比較例
７のマトリックス部のＥＰＭＡ写真を示す。実施例２の
１００°Ｃ／ｈｒで降温したものはペリクレース粒間以
外にペリクレース中に１〜２ミクロン程度のスピネル粒
が存在しているのが認められた。また、比較例７の１０
°Ｃ／ｈｒで降温したものではペリクレース内部にスピ
ネルが認められず、降温速度による析出状態の差異が生
じた。急速降温品ではペリクレース内部にスピネルの存
在が認められる。その析出形状は数ミクロンと小さく、
熱膨張ギャップによるマイクロクラックが生じにくいと
考えられ、耐消化性が良好になったと考えられる。ま
た、焼成温度は１８００°Ｃでは耐消化性が顕著に悪化
した。1 and 2 show EPMA photographs of the matrix portion of Example 2 and Comparative Example 7, respectively. In the case of cooling at 100 ° C./hr in Example 2, it was recognized that spinel grains of about 1 to 2 μm were present in the periclase other than between the periclase grains. In addition, 10 of Comparative Example 7
In the case where the temperature was lowered at ° C / hr, spinel was not found inside the periclase, and there was a difference in the precipitation state depending on the temperature decreasing rate. In the rapidly cooled product, the presence of spinel is found inside the periclase. The deposited shape is as small as a few microns,
It is considered that microcracks due to the thermal expansion gap are unlikely to occur and that the digestion resistance is improved. When the firing temperature was 1800 ° C, the digestion resistance was significantly deteriorated.
【００２２】表３、表４に実施例に使用された原料及び
添加物の物性を示す。表５に、実施例１〜４と同様の方
法で混練、成形、乾燥したものを１７００°Ｃで焼成し
た本発明の実施例によるれんがの品質を示す。比較例と
比べて１２００°Ｃ及び１４００°Ｃでの曲げ強度は同
等であった。Physical properties of raw materials and additives used in Examples are shown in Tables 3 and 4. Table 5 shows the quality of the bricks according to the examples of the present invention obtained by kneading, molding, and drying the kneaded, molded, and dried products in the same manner as in Examples 1 to 4 and firing the samples at 1700 ° C. The bending strengths at 1200 ° C and 1400 ° C were similar to those of the comparative example.
【００２３】[0023]
【表１】 [Table 1]
【００２４】[0024]
【表２】 [Table 2]
【００２５】[0025]
【表３】 [Table 3]
【００２６】[0026]
【表４】 [Table 4]
【００２７】[0027]
【表５】 [Table 5]
【００２８】[0028]
【発明の効果】本発明の焼成マグネシア・スピネルれん
がの製造方法より、熱間強度を損なうことなく、焼成セ
メント用ロータリーキルン焼成帯の内張りとして好適な
耐消化性に優れたマグスピネル系れんがが得られる。ま
た、耐消化性が優れることにより長期保存が可能とな
る。EFFECTS OF THE INVENTION According to the method for producing a fired magnesia spinel brick of the present invention, it is possible to obtain a magspinel brick having excellent digestion resistance, which is suitable as an inner lining of a rotary kiln firing zone for firing cement without impairing hot strength. Further, the excellent digestion resistance enables long-term storage.
【図１】 本発明の実施例の粒子構造のＥＰＭＡ写真を
示す。FIG. 1 shows an EPMA photograph of the grain structure of an example of the present invention.
【図２】 比較例の粒子構造のＥＰＭＡ写真を示す。FIG. 2 shows an EPMA photograph of the grain structure of a comparative example.
Claims (1)
ｇＯ−Ａｌ2Ｏ3スピネルクリンカー５〜５０重量％とか
らなる耐火性骨材に、金属鉄粉末、あるいは、Ａｌ2Ｏ3
超微粉を添加した配合原料を焼成してマグネシア・スピ
ネル系れんがを製造する方法であって、 その焼成温度範囲を１４００〜１７５０°Ｃとし、この
焼成温度範囲から５０°Ｃ／ｈｒ以上の降温速度で降温
することを特徴とする焼成マグネシア・スピネルれんが
の製造方法。1. A MgO clinker 50-95% by weight and M
A refractory aggregate composed of 5 to 50% by weight of gO-Al 2 O 3 spinel clinker, metallic iron powder, or Al 2 O 3
A method for producing a magnesia-spinel brick by firing a compounded raw material to which ultrafine powder has been added, the firing temperature range being 1400 to 1750 ° C, and a temperature lowering rate of 50 ° C / hr or more from this firing temperature range. A method for producing a fired magnesia / spinel brick, which is characterized by lowering the temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7319561A JPH09142917A (en) | 1995-11-13 | 1995-11-13 | Production of calcined magnesia-spinel brick |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7319561A JPH09142917A (en) | 1995-11-13 | 1995-11-13 | Production of calcined magnesia-spinel brick |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09142917A true JPH09142917A (en) | 1997-06-03 |
Family
ID=18111646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7319561A Pending JPH09142917A (en) | 1995-11-13 | 1995-11-13 | Production of calcined magnesia-spinel brick |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09142917A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2933236A1 (en) * | 2014-04-15 | 2015-10-21 | Refractory Intellectual Property GmbH & Co. KG | Refractory ceramic formulation, use of such a formulation and a metallurgical melting vessel |
-
1995
- 1995-11-13 JP JP7319561A patent/JPH09142917A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2933236A1 (en) * | 2014-04-15 | 2015-10-21 | Refractory Intellectual Property GmbH & Co. KG | Refractory ceramic formulation, use of such a formulation and a metallurgical melting vessel |
| WO2015158441A1 (en) * | 2014-04-15 | 2015-10-22 | Refractory Intellectual Property Gmbh & Co. Kg | Refractory ceramic batch composition, use of a batch composition of this type, and metallurgical melting vessel |
| EA030082B1 (en) * | 2014-04-15 | 2018-06-29 | Рифрэктори Интеллектчуал Проперти Гмбх Унд Ко. Кг | Refractory ceramic batch composition, use of a batch composition of this type, and metallurgical melting vessel |
| US10239791B2 (en) | 2014-04-15 | 2019-03-26 | Refractory Intellectual Property Gmbh & Co. Kg | Refractory ceramic batch composition, use of a batch composition of this type, and metallurgical melting vessel |
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