JPH0388761A - Magnesia-chrome refractory - Google Patents
Magnesia-chrome refractoryInfo
- Publication number
- JPH0388761A JPH0388761A JP1226649A JP22664989A JPH0388761A JP H0388761 A JPH0388761 A JP H0388761A JP 1226649 A JP1226649 A JP 1226649A JP 22664989 A JP22664989 A JP 22664989A JP H0388761 A JPH0388761 A JP H0388761A
- Authority
- JP
- Japan
- Prior art keywords
- magnesia
- zirconia
- refractories
- refractory
- alumina
- 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
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 31
- 229910052804 chromium Inorganic materials 0.000 claims description 12
- 239000011651 chromium Substances 0.000 claims description 12
- 239000002994 raw material Substances 0.000 claims description 12
- 239000011819 refractory material Substances 0.000 abstract description 14
- 238000004901 spalling Methods 0.000 abstract description 8
- 238000007872 degassing Methods 0.000 abstract description 3
- 239000000463 material Substances 0.000 abstract description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 6
- 229910000831 Steel Inorganic materials 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 239000000395 magnesium oxide Substances 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 239000011449 brick Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 229910000514 dolomite Inorganic materials 0.000 description 1
- 239000010459 dolomite Substances 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は耐火物に関し、特に、マグネシア−クロム質耐
火物に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to refractories, and particularly to magnesia-chromium refractories.
マグネシア−クロム質耐火物は耐火度が高いのみならず
、塩基性スラグに対する耐食性に優れるという特徴を有
し、従来から電気炉、ＲＨ脱ガス炉等で使用されている
。また、セメントロータリーキルン用耐火物としても広
く使用されている。Magnesia-chromium refractories not only have high refractory properties but also have excellent corrosion resistance against basic slag, and have been conventionally used in electric furnaces, RH degassing furnaces, and the like. It is also widely used as a refractory for cement rotary kilns.
電気炉、ＲＨ脱ガス炉等に使用される耐火物は、高温に
おいて攪拌される溶鋼流とスラグの浸食に耐え得るもの
でなければならない。スラグはＣａＯ／Ｓ ｉ Ｏ□比
が１以下から２．５までにわたって変化し、比較的低塩
基度の条件下ではマグネシア質やマグネシア−ドロマイ
ト質耐火物よりマグネシアクロム譬耐火物が優れた成績
を示している。Refractories used in electric furnaces, RH degassing furnaces, etc. must be able to withstand the erosion of molten steel flows and slag that are stirred at high temperatures. The CaO/SiO□ ratio of slag varies from less than 1 to 2.5, and under conditions of relatively low basicity, magnesia-chromium refractories have better performance than magnesia-based and magnesia-dolomite-based refractories. It shows.
マグネシア−クロムれんがの中、マグネシアとクロム鉱
を予備反応させた、いわゆる電融マグネシアクロムタリ
ンカーや焼結マグネジアクｔコムクリンカーなどの原料
を使用し、ダイレクトボンドの発達したマグネシアクロ
ムリボンドれんがは熱間強度が大きく緻密なれんが組織
を有するので、さらに優れた成績を示すが、耐スポーリ
ング性に劣るため用途が制限されている。Magnesia-chromium ribbon bricks are made using raw materials such as so-called electrofused magnesia-chromium talinker and sintered magnesia-ac-t-com clinker, which are made by pre-reacting magnesia and chromite, and have a developed direct bond. Since it has a high interlocking strength and a dense brick structure, it shows even better results, but its use is limited because it has poor spalling resistance.
さらに近年は、鋼の高級化志向が強く、また、酸素ラン
スなどを設備した苛酷な条件下にあり、これに対応する
内張り材はさらに耐用性の高いものが望まれている。Furthermore, in recent years, there has been a strong trend toward higher quality steel, and there is a need for lining materials with even higher durability to meet the harsh conditions of equipment such as oxygen lances.
耐火物の熱衝撃等による亀裂の発生を防止することは不
可能であるが、耐火物の破壊は亀裂が発生するか否かよ
り、亀裂が発達して耐火物を貫通し、割れに達するか否
かが問題であると考えられる。従って、亀裂を小さぐ分
散させることができれば耐火物はかえって割れ難くなり
、実質的に耐スポーリング性は向上する。Although it is impossible to prevent the occurrence of cracks in refractories due to thermal shock, etc., the destruction of refractories depends more on whether or not cracks develop, penetrating the refractory, and reaching cracks than whether or not they occur. The question seems to be whether or not. Therefore, if the cracks can be dispersed to a small extent, the refractory will be less likely to crack, and the spalling resistance will be substantially improved.
この発明は上記従来の事情に鑑みて提案されたものであ
って、耐スポーリング性に優れたマグネシア−クロム耐
火物を提供することを目的とするものである。This invention was proposed in view of the above-mentioned conventional circumstances, and an object thereof is to provide a magnesia-chromium refractory having excellent spalling resistance.
本発明は耐久ポーリング性の向上を達成するために以下
の手段を採用している。すなわち、マグネシア−クロム
質からなる骨材に、ジルコニアを２０〜４０重量％含有
するアルミナ−ジルコニア原料を１〜１０重量％添加し
て混合し成形・焼成したものである。The present invention employs the following means to improve durable polling performance. That is, 1 to 10% by weight of an alumina-zirconia raw material containing 20 to 40% by weight of zirconia is added to aggregate made of magnesia-chromium, mixed, molded and fired.
上記アルミナ−ジルコニア原料としては、ジルコニア２
０〜４０重量％含有するアルミナ−ジルコニア原料が使
用される。The above alumina-zirconia raw material includes zirconia 2
An alumina-zirconia raw material containing 0 to 40% by weight is used.
ジルコニアが２０重量％以下では、耐食性に乏しくなり
、４０重量％以上ではジルコニアの相転移により焼成中
もしくは使用中に高温にさらされたとき急激に収縮し、
耐火物を破壊させる。If zirconia is less than 20% by weight, corrosion resistance will be poor, and if it is more than 40% by weight, zirconia will rapidly shrink when exposed to high temperatures during firing or use due to phase transition.
Destroy refractories.
本発明は上記のような割合でジルコニアを含有するアル
ミナ−ジルコニア原料を】〜１０重量％添加することに
より、マグネシア−クロム質耐火物中に微亀裂を導入さ
せ、耐スポーリング性を向上させている。すなわち、焼
成時に上記アル稟ナージルコニア原料が膨張し、耐火物
中に微亀裂を発生させる。このように予め耐火物中に導
入した微亀裂が使用中に耐火物中に発生する亀裂の進展
を防止、あるいは、抑制しており、耐スポーリング性を
向上させている。アルミナ−ジルコニア原料が１重量％
以下では微亀裂の発生が充分ではなく、この発明の目的
を達成できない、１０重量％以上では高温でのジルコニ
アの相転移が生じて好ましくない。The present invention introduces fine cracks into the magnesia-chromium refractory and improves spalling resistance by adding ~10% by weight of alumina-zirconia raw material containing zirconia in the proportions described above. There is. That is, during firing, the alumina-zirconia raw material expands, generating microcracks in the refractory. In this way, the microcracks introduced into the refractory in advance prevent or suppress the growth of cracks that occur in the refractory during use, improving spalling resistance. Alumina-zirconia raw material is 1% by weight
If it is less than 10% by weight, the generation of microcracks will not be sufficient and the object of the present invention cannot be achieved, and if it is more than 10% by weight, phase transition of zirconia will occur at high temperatures, which is undesirable.
本発明に係る実施例を第１表に従来例とともに示した。 Examples according to the present invention are shown in Table 1 together with conventional examples.
アルミナ−ジルコニア原料（以下ＡＺ原料、ジルコニア
２５重１％）と焼結マグネシアクリンカ−と天然クロム
鉱とを第１表の実施例１〜３に示す割合で混合した後、
７６０ｋｇｆ／ｃｄの圧力で成形した。次にこの成形体
を１８００℃以上で焼成したεきの物性値を第１表にあ
わせて示す、また、比較として従来のＡＺ原料を添加し
ていないマグネシア−クロム耐火物の物性値も示す。After mixing alumina-zirconia raw material (hereinafter referred to as AZ raw material, zirconia 25% by weight), sintered magnesia clinker, and natural chromite in the proportions shown in Examples 1 to 3 in Table 1,
It was molded at a pressure of 760 kgf/cd. Next, Table 1 shows the physical properties of ε obtained by firing this molded body at 1800° C. or higher.For comparison, the physical properties of a conventional magnesia-chromium refractory to which no AZ raw material is added are also shown.
（以下余白） 第 表 それぞれの物性値は以下のようにして調べた。(Margin below) No. table The physical property values of each were investigated as follows.
気孔率（％’）：ＪＩＳ Ｒ２２Ｑ５による。Porosity (%'): According to JIS R22Q5.
かさ比重 ：ＪＩＳ Ｒ２２０５による。Bulk specific gravity: According to JIS R2205.
曲げ強さ（ｋｇｆ／ｃＪ、 ａｔ １４００℃）：ＪＩ
Ｓ Ｒ２２１３による。Bending strength (kgf/cJ, at 1400℃): JI
According to SR2213.
溶損指数 ：高周波炉内張法により評価１６５０℃×
４時間、溶鋼による溶損
量を従来例を１００とする指数で示す。Melting index: Evaluated by high frequency furnace lining method 1650℃×
The amount of corrosion loss due to molten steel for 4 hours is expressed as an index with the conventional example being 100.
耐スポーリング性：耐大物を１２００℃に保持した電気
炉に挿入し１５分間加熱、１５分間空冷のサイクルを繰
返して耐火物が剥落するまでのサイクル数を調べた。Spalling resistance: A large refractory material was inserted into an electric furnace maintained at 1200° C., and the cycle of heating for 15 minutes and air cooling for 15 minutes was repeated to determine the number of cycles until the refractory material flaked off.
以上説明したように、本願発明はマグネシア−クロム質
耐火物にアルミナ−ジルコニア原料を添加しているので
、耐スポーリング性が著しく優れた耐火物を提供するこ
とができる。As explained above, since the present invention adds an alumina-zirconia raw material to a magnesia-chromium refractory, it is possible to provide a refractory with extremely excellent spalling resistance.
Claims (1)
ニアを２０〜４０重量％含有するアルミナ−ジルコニア
原料を１〜１０重量％添加してなることを特徴とするマ
グネシア−クロム質耐火物。(1) A magnesia-chromium refractory characterized by adding 1 to 10% by weight of an alumina-zirconia raw material containing 20 to 40% by weight of zirconia to a magnesia-chromium aggregate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1226649A JPH0388761A (en) | 1989-08-31 | 1989-08-31 | Magnesia-chrome refractory |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1226649A JPH0388761A (en) | 1989-08-31 | 1989-08-31 | Magnesia-chrome refractory |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0388761A true JPH0388761A (en) | 1991-04-15 |
Family
ID=16848492
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1226649A Pending JPH0388761A (en) | 1989-08-31 | 1989-08-31 | Magnesia-chrome refractory |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0388761A (en) |
-
1989
- 1989-08-31 JP JP1226649A patent/JPH0388761A/en active Pending
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