JP3762743B2

JP3762743B2 - Lining structure of high durability secondary smelting vessel

Info

Publication number: JP3762743B2
Application number: JP2002363933A
Authority: JP
Inventors: 章弘新保; 武紀仲道
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 2002-12-16
Filing date: 2002-12-16
Publication date: 2006-04-05
Anticipated expiration: 2022-12-16
Also published as: JP2004197976A

Description

【０００１】
【発明の属する技術分野】
本発明は製鋼時に用いる溶湯の二次精錬用容器の敷き部および側壁の耐火物の内張り構造に関する。
【０００２】
【従来の技術】
二次精錬用容器の築炉方法としては、省力化のためにれんが構造から不定形耐火物の流し込み施工が主体となりつつある。しかし、この流し込み施工は、実機設備の大きさに比例して、流し込み材を仕込む混練機や乾燥機などの大型設備が必要であること、養生・乾燥時間がかかること、そして混練時に大量の粉塵が発生すること等の問題がある。これらの問題点を解決するために、さらに発展させて、流し込み材による施工だけでなく部分的にプレキャストブロックで施工する例がある。例えば、溶鋼鍋の敷き部の湯当たり部にプレキャストブロックを適用し、その他は流し込み材によって施工することが提示されている（例えば、特許文献１参照）。
【０００３】
このように、不定形耐火物は、築炉方法の簡便・省力化に関する従来技術がある。しかしながら、寿命に関しては、従来二次精錬容器に実際に適用されてきたＭｇＯ−Ｃｒ₂Ｏ₃系れんが寿命の約１／２以下である。不定形耐火物を使用すると築炉省力化によるコスト低減は認められるが、短寿命による補修回数の増加とあわせて検討すると、トータルの耐火物コストの低減化効果は決して大きくない。一方、ＭｇＯ−Ｃ系れんがは一般に転炉以後のＣ／Ｓ（ＣａＯ／ＳｉＯ₂）が高いスラグに対して、高耐溶損性を示すことが知られており、例えば転炉のウェア部や溶鋼鍋のスラグライン部に適用されている。また、二次精錬用容器への適用も試行されている。しかしながら、二次精錬容器が曲面等を有する複雑形状なことから、れんが施工は不定形耐火物より築炉負荷が増加するという問題がある。
【０００４】
【特許文献１】
特開平６−７１４２２号公報
【０００５】
【発明が解決しようとする課題】
本発明の課題は、二次精錬用容器の敷き部および側壁部のウェア部にＭｇＯ−Ｃ系れんがと不定形耐火物の両者を併用・敷設し、築炉作業の効率化を図るとともに、ＭｇＯ−Ｃ系れんがを敷設した部位の局部溶損を軽減し、その耐用性を向上することにある。
【０００６】
【課題を解決するための手段】
本発明は、敷き部および側壁部の稼働側（ウェア部）耐火物が、ＭｇＯ−Ｃ系れんがと不定形耐火物とし、さらに、前記稼働面側の耐火物の背面側（パーマ部）の耐火物が不定形耐火物により構成する内張構造の二次精錬用容器を提供することである。
さらに、二次精錬容器のウェア部であらかじめ溶損が著しい部位とそうでないと予想される部位に対応して、前者の溶損が著しい部位に高純度ＭｇＯを含有するＭｇＯ−Ｃ系れんがを設置し、後者の溶損が著しくない部位には低純度ＭｇＯ含有のＭｇＯ−Ｃ系れんが、あるいは不定形耐火物を敷設することで施工時間の短縮化および耐用性を向上させた二次精錬用容器を提供することである。
【０００７】
【発明の実施の形態】
本発明は、二次精錬容器を構成する耐火物の各部位の耐用性および施工性を考慮して、れんがと不定形耐火物（流し込み材、プレキャストブロック）の複合構造を有することを特徴とする。使用するれんが材は、ＭｇＯ−Ｃ系れんがとする。他にはＭｇＯ−Ｃｒ₂Ｏ₃系れんがの使用も可能だが、れんが使用後の処理に起こる環境問題から使用しない。
【０００８】
一方、本発明に使用する不定形耐火物材は、耐用性が良好とされ、且つウェアとして実績もあるアルミナ−マグネシア質、アルミナ−スピネル質、アルミナ−スピネル−マグネシア質、そしてジルコン等のジルコニア質が使用できる。さらに、耐熱衝撃性が必要と考えられる場合には、不定形耐火物に各種金属ファイバーやその他のファイバー類、例えば有機繊維、炭素繊維等を添加しても良い。そして、形態は複雑形状に施工しやすい流し込みまたは耐用性のあるプレキャストブロックのどちらでも良い。施工は、「溶損が著しい」部位と「溶損が著しくない」部位に対応して、前者部位に高純度ＭｇＯを含有するＭｇＯ−Ｃ系れんがを設置し、後者部位に低純度ＭｇＯを含有するＭｇＯ−Ｃ系れんが、あるいは不定形耐火物の流し込み材あるいはプレキャストブロックを設置することが好ましい。ここで、高純度ＭｇＯとは、純度９８％以上とし、低純度ＭｇＯは純度９８％未満とする。
【０００９】
「溶損が著しい」部位の判断は、種々の判断基準が考えられるが、従来の耐火物で実際の設備に内張りした耐火物の各部位の溶損速度を傾向管理し、その溶損速度の実績でもって判断するのが好ましい。例えば、使用部位の中で最小溶損速度の部位に対して予め決めた基準の数値以上の溶損速度の部位を「溶損の著しい部位」とし、予め決めた基準の数値未満の溶損速度の部位を「溶損の著しくない部位」として判断基準とするのが良く、予め決めた基準の数値としては、最小溶損速度の部位に対して１．５倍を予め決めた基準の数値とするのが特に好ましい。
【００１０】
以下に各耐火物の設置および構造について説明する。
「敷き部」や「壁部」に、従来のれんが積みに見られるような複雑な形状のれんがを組み合わせて築造することは無く、単純形状で取り扱いやすい寸法のＭｇＯ−Ｃれんがを稼動面側の「溶損が著しい」部位に設置し、反対に稼動面側の目地や周囲等の「溶損が著しくない」部位には不定形耐火物を使用し、その背面側にもまた不定形耐火物を使用する。このことにより、ＭｇＯ−Ｃれんがの敷設の際にれんが積みの高度な築炉技能は要せず、さらに築炉時間の短縮化の効果がある。
【００１１】
ここで、稼働面のＭｇＯ−Ｃれんがが溶損を引き起こし、れんがの残り厚さが減少する場合でも、背面に設置した目地のない不定形耐火物が露出するか否かを管理しておけば、目地を有するＭｇＯ−Ｃれんがを十分使いきることができるといった優れた利点がある。しかも、不定形耐火物の方は、先述したように従来ウェア部にて使用実績がある材質のため、湯洩れ等のトラブルを回避でき設備の安定稼働に結びつく。
【００１２】
ＭｇＯ−Ｃれんがと不定形耐火物の複合構造を適用する二次精錬用容器は、ＲＨ（Ruhrstahl-Heraus）式、ＤＨ（Dortmunt-Horde）式、ＣＡＳ（Composition Adjustment by Sealed Argon Bubbling）式等のいずれでもよい。この中で、内部構造が複雑な形状をなすＲＨ式二次精錬用容器（以下ＲＨと呼ぶ）の敷き部および側壁部へのＭｇＯ−Ｃれんがと不定形耐火物の適用例を以下に説明する。
【００１３】
先述した要領でＭｇＯ−ＣれんがをＲＨ敷き部に敷設する場合、１種あるいは２種の単純形状（例えば直方体）のれんがを用意する。これらのＭｇＯ−Ｃれんがを、耐火物の各部位の溶損速度を傾向管理した結果、「溶損が著しい（溶損速度が最小溶損速度の部位に対して１．５倍以上ある）」部位である中ノ島部とその周囲に敷き詰める。さらに、やはり環流管や側壁部の「溶損が著しい」部位にあらかじめＭｇＯ−Ｃれんがで組み合わせ製作したものを設置する。このように稼働中に損傷が大きく現れると判断できる箇所には、十分耐用が期待されるＭｇＯ−Ｃれんがを用い、その他の箇所で、「溶損が著しくない（溶損速度が最小溶損速度の部位に対して１．５倍未満である）」はそれよりもＭｇＯ純度の低いＭｇＯ−Ｃれんがあるいは不定形耐火物を適用しても良い。敷き部のＭｇＯ−Ｃれんがの隙間や周囲に使用する不定形耐火物は、流し込み材あるいはプレキャストブロックのどちらでも良い。次に、壁に設置したＭｇＯ−Ｃれんがの裏側にも、不定形耐火物を使用するが、ここは隙間が狭いことから、施工のし易い流し込み材が良い。以上の単純形状のＭｇＯ−Ｃれんがと不定形耐火物との組み合わせにより、築炉作業が簡単であり、さらに内張り全域にわたり高純度ＭｇＯを含有するＭｇＯ−Ｃ材料（高級材）を用いる必要がなく、高級材は必要箇所にとどめた経済的に優れた二次精錬用容器が現出できる。
【００１４】
【実施例】
ＲＨ二次精錬用容器の下部槽の敷き部および側壁部の内張りに対して、ＭｇＯ−Ｃれんがを適用した時の敷設構造とその効果について説明する。図１は、ＲＨ二次精錬用容器の下部槽の上面図、そして図２には断面図を示す。上面図からは敷き部のＭｇＯ−Ｃれんがおよび不定形耐火物の配置を、そして断面図からは敷き部および側壁部の稼働面（ウェア部）と背面（パーマ部）の配置関係が判るように示した。ここで、前記の如く従来の耐火物で実際の設備に内張りした耐火物の各部位の溶損速度を傾向管理した結果、最小溶損速度の部位に対して１．５倍以上となって著しく損傷する部位は、敷き部では、２つの環流管の間の中ノ島部、壁部が環流間に近い部位であった。この損傷部位にＭｇＯ−Ｃれんがを優先的に使用することとした。ＭｇＯ−Ｃれんがの形状は単純形状にし、敷き部に適用した直方体（図中番号１）、円筒（図中番号２）、そして側壁板（図中番号３）とした。さらに、図中番号４の稼働面、図中番号１、２稼働面の背面および５（図中番号３稼働面の背面）に示す部位に不定形耐火物を使用し、材質はアルミナ−スピネル質流し込み材とした。具体的には、ＭｇＯ−Ｃれんが同士の間隔をそれぞれ最短距離５０〜１５０ｍｍとし、そこにアルミナ−スピネル質流し込み材を充填し、固まる前に振動棒（バイブレータ）により、加振して流し込み材内部の気泡を除去した。その後、容器内部全体をガスバーナにより１２００℃まで予熱してから、二次精錬の実操業に供した。
ここで、比較のために、敷き部および側壁部全域にＭｇＯ−Ｃれんがを使用した下部槽とアルミナ−スピネル質の流し込み材を使用した下部槽を準備し、同じように実操業に供し比較した。二次精錬１回分の使用溶鋼量は、約３００ｔｏｎ、温度を１６００〜１６３０℃とした。
【００１５】
実機稼働した時のＭｇＯ−Ｃれんがと不定形耐火物の複合構造、ＭｇＯ−Ｃれんがのみあるいは流し込み不定形耐火物のみで構成した単一構造それぞれの寿命を表１に示す。流し込み材の単一構造のＲＨ二次精錬用容器寿命時間を１００とした時、複合構造およびＭｇＯ−Ｃれんが単一槽の寿命指数は１６０、１８５となり、それぞれ６０％および８５％延びた。これは寿命律速である、あらかじめ溶損が大きいと予想された中の島（図中番号１）や壁部（図中番号３）に、不定形に代わりＭｇＯ−Ｃれんがを使用したことが、寿命延長に結びついたと推測できた。
【００１６】
なお、ＭｇＯ−Ｃれんがそして不定形耐火物との複合構造下部槽とＭｇＯ−Ｃれんがのみで構成される比較下部槽を比較すると、下部槽寿命は同じだが、複合構造の方は寿命律速にならない「溶損が著しくない」部位に不定形耐火物を使用するため、ＭｇＯ−Ｃれんが単一構造の施工時間の１／４と短く、複合構造を採用することで簡易施工、且つ長寿命化が達成できた。さらに、本下部槽の使用後の観察より、環流方向の側壁ＭｇＯ−Ｃれんがの損傷が大きかった。特に激しい損傷箇所では、背面に施した流し込み不定形材が露出した。即ち、背面に不定形材が存在することでＭｇＯ−Ｃれんがを使いきることが可能、そして不定形材に目地が無いことからＭｇＯ−Ｃれんがが消滅したか否かの判定にも有用であること等が判った。さらに、この箇所のＭｇＯ−Ｃれんがを取り外し、新しいれんがに差し替えることで簡単に補修作業が完了した。
【００１７】
【表１】

【００１８】
【発明の効果】
本発明は、敷き部および側壁部の稼働面にＭｇＯ−Ｃれんが、背面に不定形耐火物を使用する複合構造の二次精錬用容器を使用することで、施工が容易であり、長寿命そして補修が簡単に行え、安定した操業を可能にした。
【図面の簡単な説明】
【図１】本発明を適用したＲＨ式二次精錬用容器の下部槽上面図（敷き部、側壁部のＭｇＯ−Ｃれんが配置）。
【図２】図１のＡ−Ａ断面で、ＲＨ式二次精錬用容器の下部槽断面図（敷き部、側壁部のＭｇＯ−Ｃれんがと不定形耐火物の配置）。
【符号の説明】
１中ノ島部２円筒部
３側壁部４、５不定形耐火物[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laying structure of a refractory on a laying portion and a side wall of a secondary refining vessel for molten metal used during steelmaking.
[0002]
[Prior art]
As a method of constructing a secondary smelting vessel, in order to save labor, the construction of pouring irregular refractories from a brick structure is becoming the main component. However, this casting construction requires a large facility such as a kneader or a dryer for feeding the casting material in proportion to the size of the actual equipment, curing and drying time, and a large amount of dust during kneading. There are problems such as In order to solve these problems, there is an example in which the construction is further developed and the construction is performed not only by the casting material but also partially by the precast block. For example, it is proposed that a precast block is applied to the hot water contact portion of the ladle portion of the molten steel pan, and the others are constructed by a casting material (see, for example, Patent Document 1).
[0003]
As described above, the conventional refractory has a conventional technique relating to the simple and labor-saving construction of the furnace. However, regarding the lifetime, the MgO—Cr ₂ O ₃ type brick that has been actually applied to the secondary refining vessel is about ½ or less of the lifetime. If an irregular refractory is used, a cost reduction due to labor saving in the furnace is recognized, but when considered together with an increase in the number of repairs due to a short life, the effect of reducing the total refractory cost is not significant. On the other hand, MgO-C bricks are generally known to exhibit high melt resistance against slag having a high C / S (CaO / SiO ₂ ) after the converter. It is applied to the pan slag line. In addition, application to secondary refining vessels is also being tried. However, since the secondary smelting vessel has a complicated shape with a curved surface or the like, there is a problem that brick construction increases the furnace load more than an irregular refractory.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-71422
[Problems to be solved by the invention]
The object of the present invention is to use and lay both MgO-C brick and amorphous refractory on the laying part of the secondary smelting vessel and the wear part of the side wall part, and to improve the efficiency of the furnace construction work. The purpose is to reduce local melting of the site where the -C brick is laid and to improve its durability.
[0006]
[Means for Solving the Problems]
In the present invention, the working side (wear part) refractory of the laying part and the side wall part is an MgO-C brick and an indeterminate refractory, and the refractory on the back side (perm part) of the refractory on the working surface side. An object of the present invention is to provide a secondary refining vessel having a lining structure in which an object is constituted by an irregular refractory.
In addition, in the wear part of the secondary smelting vessel, MgO-C bricks containing high-purity MgO are installed in the former part where the erosion is expected to correspond to the part where the erosion is expected to be not. However, a secondary refining vessel that shortens construction time and improves durability by laying MgO-C bricks containing low-purity MgO or irregular refractories at the site where the latter is not significantly damaged. Is to provide.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is characterized by having a composite structure of a brick and an irregular refractory (a casting material, a precast block) in consideration of the durability and workability of each part of the refractory constituting the secondary smelting vessel. . The brick material used is an MgO-C brick. In addition, MgO—Cr ₂ O ₃ bricks can be used, but they are not used because of environmental problems that occur in the treatment after the brick is used.
[0008]
On the other hand, the amorphous refractory material used in the present invention has good durability and has a proven track record for wear, such as alumina-magnesia, alumina-spinel, alumina-spinel-magnesia, and zirconia such as zircon. Can be used. Furthermore, when it is considered that thermal shock resistance is necessary, various metal fibers and other fibers such as organic fibers and carbon fibers may be added to the amorphous refractory. And the form may be either a cast or a precast block with durability that can be easily constructed into a complex shape. For the construction, the MgO-C brick containing high-purity MgO is installed in the former part, and the low-purity MgO is contained in the latter part corresponding to the part where the melting damage is remarkable and the part where the melting damage is not remarkable. It is preferable to install a casting material or precast block of MgO-C brick, or an irregular refractory. Here, high purity MgO has a purity of 98% or more, and low purity MgO has a purity of less than 98%.
[0009]
Various judgment criteria can be considered for the judgment of the part where "severe damage is remarkable", but the trend of the damage rate of each part of the refractory lined on the actual equipment with conventional refractory is managed and It is preferable to judge based on actual results. For example, a part of the used part that has a damage rate that is greater than or equal to a predetermined reference value with respect to a part with a minimum damage rate is defined as a "part with significant damage", and a damage rate that is less than a predetermined reference value. It is good to use as a judgment standard as a "part where there is no remarkable damage". As a predetermined reference numerical value, a reference numerical value determined in advance is 1.5 times as high as a minimum melting rate part. It is particularly preferable to do this.
[0010]
The installation and structure of each refractory will be described below.
There is no need to build a combination of bricks with complex shapes, such as those found in conventional bricks, on the “laying part” or “wall part”. Installed in the area where “severe damage is significant”, and on the other hand, use the non-standard refractory for the joints and surroundings on the working surface side, etc. Is used. Thus, when laying MgO-C bricks, advanced building skills for building bricks are not required, and the construction time can be shortened.
[0011]
Here, even if the MgO-C brick on the working surface causes melting damage and the remaining thickness of the brick is reduced, it is possible to manage whether or not the unshaped refractory with the joint installed on the back surface is exposed. There is an excellent advantage that the MgO-C brick having joints can be fully used. In addition, since the unshaped refractory is a material that has been used in the conventional wear section as described above, it is possible to avoid troubles such as leakage of water and lead to stable operation of the equipment.
[0012]
Secondary refining containers that apply a composite structure of MgO-C brick and amorphous refractory are RH (Ruhrstahl-Heraus), DH (Dortmunt-Horde), CAS (Composition Adjustment by Sealed Argon Bubbling), etc. Either is acceptable. Among these, an application example of the MgO-C brick and the amorphous refractory to the laying part and the side wall part of the RH type secondary refining vessel (hereinafter referred to as RH) having a complicated internal structure will be described below. .
[0013]
When the MgO-C brick is laid on the RH laying portion in the manner described above, one type or two types of simple shape (for example, rectangular parallelepiped) bricks are prepared. As a result of trend management of the erosion rate of each part of the refractory, these MgO-C bricks are "severe erosion (the erosion rate is 1.5 times or more than the minimum erosion rate part)" Cover the area around Nakanoshima and its surroundings. In addition, the one made by combining with MgO-C bricks in advance is installed in the part of the reflux tube or the side wall portion where the “melting damage is significant”. In this way, MgO-C bricks that are expected to be sufficiently durable are used in places where it can be determined that damage appears to be significant during operation, and in other places, “there is no significant erosion (the erosion rate is the minimum erosion rate). It may be less than 1.5 times as much as that) ”, and MgO—C bricks or amorphous refractories with lower MgO purity may be applied. The irregular refractory used in the gaps and surroundings of the MgO-C brick at the laying part may be either a casting material or a precast block. Next, an amorphous refractory is also used on the back side of the MgO-C brick installed on the wall. However, since the gap is narrow, a pouring material that is easy to construct is preferable. The combination of the simple shape MgO-C brick and the irregular refractory makes it easy to build a furnace and eliminates the need to use a MgO-C material (high-grade material) containing high-purity MgO throughout the lining. As a result, an economically superior secondary refining vessel can be developed, where high-grade materials are kept at the necessary locations.
[0014]
【Example】
The laying structure and its effect when MgO-C brick is applied to the laying of the lower tank and the lining of the side wall of the RH secondary refining vessel will be described. FIG. 1 is a top view of a lower tank of the RH secondary refining vessel, and FIG. 2 is a cross-sectional view. From the top view, the layout of the MgO-C brick and the irregular refractory in the laying part, and from the cross-sectional view, the layout relationship between the working surface (wear part) and the back (perm part) of the laying part and the side wall part Indicated. Here, as a result of the trend management of the erosion rate of each part of the refractory lined on the actual equipment with the conventional refractory as described above, it is significantly more than 1.5 times the minimum erosion rate part. In the laying part, the damaged part was the Nakanoshima part between the two reflux tubes and the wall part was close to the reflux. It was decided to use MgO-C brick preferentially at the damaged site. The shape of the MgO-C brick was a simple shape, which was a rectangular parallelepiped (number 1 in the figure), a cylinder (number 2 in the figure), and a side wall plate (number 3 in the figure) applied to the laying part. In addition, an amorphous refractory is used for the working surface of No. 4 in the figure, the back of the No. 1, 2 working surface in the figure and 5 (the back of the No. 3 working surface in the figure), and the material is alumina-spinel. A casting material was used. Specifically, the distance between the MgO-C bricks is set to the shortest distance of 50 to 150 mm, and the alumina-spinel casting material is filled therein, and before being hardened, it is vibrated by a vibrating rod (vibrator). The bubbles were removed. Thereafter, the entire inside of the container was preheated to 1200 ° C. with a gas burner, and then subjected to the actual operation of secondary refining.
Here, for comparison, a lower tank using MgO-C brick and a lower tank using an alumina-spinel casting material were prepared in the entire area of the floor and the side wall, and the same was used for actual operation and compared. . The amount of molten steel used for one secondary refining was about 300 tons, and the temperature was 1600 to 1630 ° C.
[0015]
Table 1 shows the lifetimes of the MgO-C brick and amorphous refractory composite structure when the actual machine is operated, and the MgO-C brick alone or the single structure composed only of the cast amorphous refractory. Assuming that the life time of the RH secondary refining vessel having a single structure of the casting material is 100, the life index of the composite structure and the single MgO-C brick tank is 160 and 185, which are extended by 60% and 85%, respectively. This is a life-determining rate, and the use of MgO-C bricks instead of indefinite shapes for the islands (number 1 in the figure) and walls (number 3 in the figure), which had been predicted to have large melting damage in advance, extended the life. I was able to guess that it was tied to.
[0016]
In addition, when the lower structure of the composite tank composed only of MgO-C brick and the non-shaped refractory is compared with the lower tank composed of only MgO-C brick, the life of the lower structure is the same, but the composite structure is not life-limited. Because an irregular shaped refractory is used in the area where “no significant damage” occurs, MgO-C brick is as short as ¼ of the construction time of a single structure, and by adopting a composite structure, simple construction and long life can be achieved. I was able to achieve it. Furthermore, the damage of the side wall MgO-C brick in the reflux direction was greater than the observation after using the lower tank. In particular, in the severely damaged part, the cast irregular shape material applied to the back surface was exposed. That is, it is possible to use up the MgO-C brick because of the presence of the irregular shaped material on the back surface, and it is also useful for determining whether the MgO-C brick has disappeared because there is no joint in the irregular shaped material. I understood that. Furthermore, the MgO-C brick at this location was removed and replaced with a new brick, and the repair work was easily completed.
[0017]
[Table 1]

[0018]
【The invention's effect】
The present invention uses a secondary refining vessel with a composite structure that uses MgO-C brick on the working surface of the laying portion and the side wall portion and an irregular refractory on the back surface. Repair can be done easily and stable operation is possible.
[Brief description of the drawings]
FIG. 1 is a top view of a lower tank of an RH-type secondary refining vessel to which the present invention is applied (laying of MgO—C bricks on a floor portion and a side wall portion).
FIG. 2 is a cross-sectional view of the lower tank of the RH type secondary refining vessel (arrangement of MgO—C bricks and amorphous refractories on the side walls and side walls) in the AA cross section of FIG. 1;
[Explanation of symbols]
1 Nakanoshima part 2 Cylindrical part 3 Side wall part 4, 5 Indeterminate refractory

Claims

The refractory on the working surface side (wear part) in the laying part and the side wall part is MgO-C type brick and an irregular refractory, and the refractory on the back side (perm part) of the refractory on the working surface side is not suitable. A lining structure for a highly durable secondary refining vessel, characterized by comprising a regular refractory.

The working surface (wear part) of the laying part and the wall corresponds to the part where the erosion damage is remarkable and the part where the erosion damage is not so. the site latter melting is not significantly containing low-purity MgO MgO-C-based brick or lining structure of high durability secondary refining vessel of claim 1, wherein the laying monolithic refractories .