JP3303039B2 - Precast block for electric furnace ceiling - Google Patents
Precast block for electric furnace ceilingInfo
- Publication number
- JP3303039B2 JP3303039B2 JP08592196A JP8592196A JP3303039B2 JP 3303039 B2 JP3303039 B2 JP 3303039B2 JP 08592196 A JP08592196 A JP 08592196A JP 8592196 A JP8592196 A JP 8592196A JP 3303039 B2 JP3303039 B2 JP 3303039B2
- Authority
- JP
- Japan
- Prior art keywords
- electric furnace
- precast block
- furnace ceiling
- ceiling
- block
- 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
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Ceramic Products (AREA)
- Furnace Housings, Linings, Walls, And Ceilings (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は電気炉天井部において耐
スポーリング性と耐蝕性の両者を改善したプレキャスト
ブロックに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast block having improved spalling resistance and corrosion resistance in an electric furnace ceiling.
【０００２】[0002]
【従来の技術】製鋼用電気炉は近年、その総合コストが
安価なため設備が増加しつつあり、操業率も増加傾向に
ある。そんな中で電気炉の天井部１は元来、比較的長期
耐用を示す（１〜２カ月）部位であったが炉修と炉修期
間の延長化及び作業時間の短縮等により、より細かな改
善の対象となってきた。従来、天井部１は定形のシリカ
−アルミナ質れんがが図１の如く、複雑な設計の上で施
工されていた。かつ、単品れんがの脱落を防止するため
メタルケースを配する場合が多かった。従って、施工時
間と施工技術が要求され、かつ細かなれんがの組合せの
ため損傷による残寸小や熱サイクルによる緩みのため使
用中に脱落等が発生し炉修と炉修の期間が短くなった
り、突発炉修が発生していた。この改善として大型のプ
レキャストブロック２の使用が開始された。代表的な設
計を図２に示す。プレキャストブロック材質としては耐
スポーリング性と耐蝕性を考慮してＡｌ2Ｏ3含有量が９
０重量％程度のハイアルミナ質が採用された。定形れん
がに比較しプレキャストブロックは一般的にスポール性
に優れ、大型形状が可能なことから非常に有効な改善策
であった。とりわけ、施工については一体品から３分割
品の設計が主流で各々のブロックをクレーンで吊り上げ
施工台に設置しブロック間の隙間はキャスタブルで充填
するだけで完成する。施工時間は実質３時間程度で従来
の５分の１程度に短縮された。しかし、その材質改善に
ついてはまだ不十分であり、ハイアルミナ質の領域でク
ロム成分の添加、シリカ成分量の調整により耐スポーリ
ング性、耐蝕性をコントロールする範囲で更なる寿命延
長のニーズには満足するものはなかった。2. Description of the Related Art In recent years, electric furnaces for steelmaking have been increasing in facilities due to their low total cost, and the operating rate has also been increasing. Under such circumstances, the ceiling part 1 of the electric furnace was originally a part showing a relatively long service life (1-2 months), but due to furnace repair, extension of the furnace repair period and shortening of work time, etc. It has been targeted for improvement. Conventionally, the ceiling 1 has been constructed of a fixed silica-alumina brick on a complicated design as shown in FIG. In addition, a metal case was often provided to prevent a single brick from falling off. Therefore, the construction time and construction technique are required, and the combination of fine bricks causes the residual size to be small due to damage, and the thermal cycle causes loosening, etc., which may cause falling off during use, shortening the furnace repair period. , Sudden furnace repair had occurred. Use of a large precast block 2 has been started as an improvement. A representative design is shown in FIG. The precast block material has an Al 2 O 3 content of 9 in consideration of spalling resistance and corrosion resistance.
A high alumina material of about 0% by weight was employed. The precast block was a very effective improvement measure compared to the fixed brick because it generally has a better spalling property and can be formed in a large shape. In particular, as for the construction, the design of one-piece to three-piece products is the mainstream, and each block is lifted up by a crane, installed on a construction table, and the gap between the blocks is completed simply by casting. The construction time was substantially three hours, which was reduced to about one-fifth of the conventional one. However, the improvement of the material is still inadequate, and the addition of a chromium component in the high-alumina region and the adjustment of the amount of the silica component require spalling and corrosion resistance. Nothing was satisfactory.
【０００３】[0003]
【発明が解決しようとする課題】現在の電気炉天井ブロ
ックは表面の地金付着及び浸透と熱サイクルによる構造
的スポーリングが主要因であり、この改善が大きな課題
となっている。The current electric furnace ceiling block is mainly caused by structural metal spalling due to adhesion of metal on the surface and infiltration and thermal cycling, and its improvement is a major problem.
【０００４】[0004]
【課題を解決するための手段】電気炉天井ブロックはス
クラップ溶解時のスプラッシュ付着及び溶解アーク熱に
よる表面層への侵入、そしてスクラップ投入時の急冷に
よる表面層の剥離と考えられる。そこで、浸透防止効果
を有するＣr2Ｏ3成分の添加を考えた。但し、Ｃr2Ｏ3単
味の添加は従来の技術であり使用時の雰囲気によりＣr2
Ｏ3の蒸発による耐蝕性の低下、あるいはＦe2Ｏ3とスピ
ネル形成により生じる膨張率の増加が表面クラックを招
き、結果として効果が殆ど出ない経験もある。そこで、
Ｃr2Ｏ3を事前に複合スピネル化し、より安定した形態
で添加、存在せしめることを考案した。つまり、マグネ
シア−クロム質れんが（以降マグクロれんがと称す）で
代表されるＭgＯ組成を中心とし他はＡｌ2Ｏ3、Ｆe2Ｏ3
組成の複合スピネル化されたものの添加である。これは
マグネシアクリンカーと天然クロム鉱石、電融マグクロ
クリンカー等を種々混合し焼成した焼成体を所定の粒度
に調整したものである。この焼成体の組成は限定される
ものではないが基本領域としてはＭgＯ ５０〜７０％、
Ｃr2Ｏ3 １５〜２５％、その他 ２５％以下が考えられ
る。プレキャスト品の一般粒度構成から判断し骨材領域
である５ｍｍ以上にて検討した。それらの効果は種々試
作することにより確認した。試作時の母材は一般品であ
るハイアルミナセメントタイプのキャスタブルとしたが
マグネシア系等も同等の効果があると考えられる。表
１，２に示される試作結果によると４０重量％以上の添
加は大きな強度低下を招くので天井という部位を考慮す
ると垂れ下がり、脱落の恐れから範囲外とした。また、
１０重量％以下では耐スポーリング性への寄与効果が小
さいと考えられ範囲外とした。更に５０ｍｍ以上の径に
なるとブロックの強度が著しく低下するため径の上限を
５０ｍｍと設定した。マグクロ系複合スピネル体は残存
膨張特性を有しておりブロックのマトリックスとなるＡ
ｌ2Ｏ3組成とはその点で大きな相違があるため添加した
焼成体骨材の周囲には所々微き裂が存在しており、これ
が熱スポーリング抵抗性には有利となりスポーリングテ
ストにおいては良好な結果を示した。スラグテストにお
いてもスラグの浸透が抑制されており骨材自身の高耐蝕
性と合わせ微き裂のマイナス分を総合的にはプラスとし
た。Means for Solving the Problems It is considered that the electric furnace ceiling block is caused by splash adhesion during scrap melting and penetration into the surface layer by melting arc heat, and peeling of the surface layer due to rapid cooling at the time of scrap input. Therefore, the addition of a Cr 2 O 3 component having a permeation preventing effect was considered. However, the addition of Cr 2 O 3 Plain is Cr 2 by atmosphere in use are conventional art
In some cases, a decrease in corrosion resistance due to evaporation of O 3 , or an increase in expansion coefficient caused by formation of Fe 2 O 3 and spinel causes a surface crack, resulting in little effect. Therefore,
It has been devised that Cr 2 O 3 is formed into a complex spinel in advance and added and present in a more stable form. That is, the composition is centered on the MgO composition represented by magnesia-chromic brick (hereinafter referred to as magcro brick), and the others are Al 2 O 3 and Fe 2 O 3.
This is the addition of a composite spinel composition. This is one in which magnesia clinker, natural chromium ore, electrofused magcroclinker, and the like are mixed in various ways and fired to obtain a predetermined particle size. Although the composition of the fired body is not limited, the basic region is MgO 50 to 70%,
Cr 2 O 3 may be 15 to 25%, and others may be 25% or less. Judging from the general grain size composition of the precast product, the study was conducted at an aggregate area of 5 mm or more. Their effects were confirmed by various trial productions. The base material at the time of the trial production was a castable of high alumina cement type, which is a general product, but it is considered that a magnesia type or the like has the same effect. According to the trial production results shown in Tables 1 and 2, the addition of 40% by weight or more causes a large decrease in strength. Also,
When the content is 10% by weight or less, the effect of contributing to spalling resistance is considered to be small. Further, when the diameter becomes 50 mm or more, the strength of the block is remarkably reduced, so the upper limit of the diameter is set to 50 mm. The magcro-based composite spinel has residual expansion characteristics and serves as a matrix for the block.
Since there is a great difference from the l 2 O 3 composition in this respect, there are some small cracks around the added fired body aggregate, which is advantageous for the heat spalling resistance and becomes poor in the spalling test. Good results were shown. In the slag test as well, the penetration of slag was suppressed, and the minus portion of the small crack was combined with the high corrosion resistance of the aggregate itself.
【０００５】[0005]
【表１】 [Table 1]
【０００６】[0006]
【実施例】８０ｔ／ｃｈ容量の電気炉の小天井部用とし
て本発明によるプレキャストブロックの適用を図った。
（図３，４）材質構成は表３に示されるようにＭgＯ ６
０重量％、Ｃr2Ｏ3 １９重量％の焼結体を５〜３０ｍｍ
径にて３０重量％添加した。鋳込み方法、乾燥方法につ
いては一般的なプレキャストブロックと同一としたが、
焼成体の吸水率が大きく、混練水分は通常より２重量％
付加した。EXAMPLE A precast block according to the present invention was applied to a small ceiling of an electric furnace having a capacity of 80 t / ch.
(FIGS. 3 and 4) The material composition was MgO 6 as shown in Table 3.
A sintered body of 0% by weight and 19% by weight of Cr 2 O 3
30% by weight in diameter was added. The casting method and drying method were the same as general precast blocks,
The water absorption of the fired body is large, and the kneading water content is 2% by weight
Added.
【０００７】[0007]
【表２】 [Table 2]
【０００８】[0008]
【発明の効果】本発明による電気炉小天井プレキャスト
ブロックを８０ｔ／ｃｈ容量の電気炉に適用した。耐ス
ポーリング性に優れ剥離が抑制されたため５１５ｃｈの
耐用を示し、従来品の平均４５０ｃｈに対し１０％の改
善効果を立証した。本発明によれば、定形れんがに比較
しプレキャストブロックは一般的にスポール性に優れ、
大型形状が可能なことから非常に有効な改善策であり、
施工時間は実質３時間程度で従来の５分の１程度に短縮
された。 The electric furnace small ceiling precast block according to the present invention was applied to an electric furnace having a capacity of 80 t / ch. Since the spalling resistance was excellent and the peeling was suppressed, the durability of 515 ch was shown, and the improvement effect of 10% was proved with respect to the average 450 ch of the conventional product. According to the present invention, compared to shaped bricks
The precast block is generally excellent in spall,
This is a very effective improvement because a large shape is possible.
The construction time is substantially three hours and reduced to about one-fifth of the conventional one.
Was done.
【０００９】[0009]
【表３】 [Table 3]
【図１】従来電気炉の天井部の設計施工を示す説明図で
ある。FIG. 1 is an explanatory view showing a design and construction of a ceiling portion of a conventional electric furnace.
【図２】従来の大型プレキャストブロックの設計説明図
である。FIG. 2 is a design explanatory view of a conventional large precast block.
【図３】本発明によるプレキャストブロック適用の説明
図である。FIG. 3 is an explanatory diagram of application of a precast block according to the present invention.
【図４】本発明によるプレキャストブロック適用の要部
縦断面図である。FIG. 4 is a longitudinal sectional view of a main part of a precast block according to the present invention.
１ 電気炉の天井部 ２ 大型プレキャストブロック ３ プレキャストブロック 1 ceiling of electric furnace 2 large precast block 3 precast block
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) F27D 1/04 C04B 35/00 C04B 35/04 C04B 35/10 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 7 , DB name) F27D 1/04 C04B 35/00 C04B 35/04 C04B 35/10
Claims (1)
の主成分をＭｇＯとＣｒ2Ｏ3としその他はＡｌ2Ｏ3、Ｆ
ｅ2Ｏ3等を含む燒結体を骨材とし１０〜４０重量％含有
し、ハイアルミナセメントタイプのキャスタブルあるい
はマグネシア系を母材とし、電気炉天井用のプレキャス
トブロックとして適用したことを特徴とする電気炉天井
用プレキャストブロック。1. The particle size is 5 mm or more and 50 mm or less, the main components of which are MgO and Cr 2 O 3, and the others are Al 2 O 3 and F
The sintered body containing e 2 O 3 or the like is used as an aggregate and contains 10 to 40% by weight, and a castable or magnesia-based high alumina cement type base material is used as a precast block for an electric furnace ceiling. Precast block for electric furnace ceiling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08592196A JP3303039B2 (en) | 1996-03-13 | 1996-03-13 | Precast block for electric furnace ceiling |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08592196A JP3303039B2 (en) | 1996-03-13 | 1996-03-13 | Precast block for electric furnace ceiling |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09243272A JPH09243272A (en) | 1997-09-19 |
| JP3303039B2 true JP3303039B2 (en) | 2002-07-15 |
Family
ID=13872253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08592196A Expired - Fee Related JP3303039B2 (en) | 1996-03-13 | 1996-03-13 | Precast block for electric furnace ceiling |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3303039B2 (en) |
-
1996
- 1996-03-13 JP JP08592196A patent/JP3303039B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09243272A (en) | 1997-09-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |