JPH0510406B2 - - Google Patents
Info
- Publication number
- JPH0510406B2 JPH0510406B2 JP62213826A JP21382687A JPH0510406B2 JP H0510406 B2 JPH0510406 B2 JP H0510406B2 JP 62213826 A JP62213826 A JP 62213826A JP 21382687 A JP21382687 A JP 21382687A JP H0510406 B2 JPH0510406 B2 JP H0510406B2
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- ladle
- blowing
- stirring
- lance
- 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 - Lifetime
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Description
産業上の利用分野
この発明は溶融金属容器、主として取鍋内の溶
鋼の昇熱方法に係り、取鍋内溶鋼にAlを添加し
酸素吹錬して溶鋼を昇熱させる方法に関する。
従来の技術
製鋼プロセスにおいて、転炉のごとき精錬炉に
おいて精錬の完了した取鍋内溶鋼を連続鋳造等に
供給し、あるいは取鍋精錬を行なう場合は、溶鋼
温度を補修することが必要である。この溶鋼温度
を補償する方法としては、例えば下記に示す方法
が知られている。
取鍋内溶鋼に発熱剤を添加し酸素吹きする方
法（特開昭54−149313、特開昭59−89708、特
開昭61−235506）。
取鍋内溶鋼中に線状の金属または合金を添加
する方法（特公昭54−29163）。
さらに詳しく説明すると、の方法は取鍋に収
容した溶鋼のAl、Si等の発熱剤を添加し、取鍋
底部から不活性ガスを吹込んで溶鋼を撹拌しなが
ら酸素吹錬して溶鋼温度を上昇させる方法であ
る。また、の溶鋼に金属または合金を添加する
方法は、不活性ガスを底部より導入して溶鋼を撹
拌しながら、上吹浸漬ランスより酸素供給と化学
量論的に等価以上の線状の金属（Al線等）また
は合金を送り込み、該ランス下端で溶鋼との接触
により溶解せしめて溶鋼温度を上昇させる方法で
ある。
従来技術の問題点
しかし、従来の前記の方法における溶鋼の
撹拌はすべて取鍋底部に設置されたポーラスプラ
グからの不活性ガス吹込みにより行なわれている
ため、ポーラスプラグの耐火物溶損、ポーラスプ
ラグの目詰り、補修工数の増大等を招き、不活性
ガス流量を増加して撹拌力を高めることができな
い。したがつて、ポーラスプラグによる底吹撹拌
では送酸速度を上げて昇熱速度を上昇させること
ができなかつた。
この発明は従来の前記問題を解決するためにな
されたものであり、溶鋼の撹拌力を高めて昇熱速
度を上昇させ得る取鍋内溶鋼の昇熱方法を提案せ
んとするものである。
発明の構成
この発明に係る取鍋内溶鋼の昇熱方法は、取鍋
内溶鋼中に溶鋼表面と取鍋底面間距離の１／２よ
り深く浸漬させたバブリングランスにより不活性
ガスを吹込んで溶鋼を撹拌し、その時発生するプ
ルームにより露出された溶鋼浴面より小さい直径
を有するシユノーケルを浸漬してスラグをカツト
した後、前記シユノーケル内の溶鋼浴面に発熱剤
を添加して上吹ランスにて酸素吹錬を行うことを
特徴するものである。
作 用
取鍋内溶鋼中にバブリングランスを溶鋼表面を
取鍋底面間距離の１／２より深く浸漬させて不活
性ガスを吹込むことによつて溶鋼を撹拌する方法
によれば、不活性ガス流量を従来のポーラスプラ
グによる方式より増大できる。つまり、大流量の
不活性ガスを吹込むことが可能となり、溶鋼の撹
拌力を高ることができるので、酸素供給速度を上
げ、昇熱速度を上昇させることが可能となるので
ある。
なお、バブリングランスを溶鋼表面と取鍋底面
間距離の１／２より深く浸漬させたのは、溶鋼表
面を取鍋底面間距離の１／２より浅いと不活性ガ
スが取鍋底面付近に届かず撹拌が不十分となるた
めである。しかし、バブリングランスは、溶鋼表
面取鍋底面間距離の２／３〜３／４より深く浸漬
するのが好ましいが、通常の100〜500トンクラス
の取鍋においては、不活性ガスが取鍋底面に強く
当たらないよう、取鍋底面との間隔を最底50〜
100cmとる必要がある。
また、上記溶鋼の撹拌によつて発生するプルー
ムにより露出する溶鋼浴面より小さい直径を有す
るシユノーケルを溶鋼中に浸漬させることによ
り、スラグのない溶解浴面を形成させることがで
きるので、このスラグのない溶鋼浴面に発熱剤を
添加することにより発熱剤と溶鋼との反応効率が
高められる。この反応効率の上昇により有価成分
の損失、スラグ中酸化物の低減がはかられる。
また、溶鋼の撹拌はバブリングランスにより行
なうので、ポーラスプラグの耐火物溶損や目詰
り、補修工数の増大等の問題がの解決できる。
具体例
第１図はこの発明方法の一実施例を示す概略図
で、１は取鍋、２は溶鋼、３はバブリングラン
ス、４は酸素ランス、５はシユノーケル、６はス
ラグ、G1はAr，CO2等の不活性ガス、G2は酸素
ガスである。８は集塵フードである。
すなわち、溶解炉で溶解した溶鋼２を取鍋１に
移し、溶鋼中に溶鋼表面と取鍋底面間距離の１／
２より深く浸漬したバブリングランス３より不活
性ガスを吹込んで溶鋼２を撹拌する。この溶鋼の
撹拌により発生するプルームにより溶鋼浴面が露
出し、この露出した溶鋼浴面７より小さい直径を
有するシユノーケル５を溶鋼中に浸漬する。この
シユノーケル５は耐火物がコーテイングれた浸漬
管でである。このシユノーケルを前記溶鋼浴面７
に浸漬することによつて、周囲の浮上スラグをカ
ツトしてシユノーケル内にスラグのない溶鋼浴面
を形成することができる。
しかる後、前記シユノーケル５内の溶鋼浴面上
に発熱剤を添加し、所定の高さに下降した酸素ラ
ンス４より酸素ガスを吹込んで酸素吹錬を開始す
る。なお、発熱剤は酸素吹錬前に全量投入する
か、もしくは吹錬中に分割投入する。
酸素吹錬終了後、溶鋼清浄性をより高めるため
バブリングを数分間継続し、しかる後バブリング
ランス３を上昇させ、続いてシユノーケル５を上
昇させることで昇熱処理を終了する。
実施例
第１図に示す設備により、第１表に示す成分を
有する溶鋼160トンを取鍋に収容し、取鍋上部か
らシユノーケル内の溶鋼表面にAlを添加して後、
溶鋼中に溶鋼表面と取鍋底面間距離の４／５〜
５／６程度浸漬させたバブリングランスからAr
ガスを吹込んで溶鋼を撹拌しながら、酸素ランス
から酸素ガスを吹込んで酸素吹錬を実施した。ま
た、比較のため従来法（底吹撹拌）により昇熱処
理を実施した。
本実施例の処理条件を第２表に、昇熱処理前後
の［Ｃ］［Ｐ］［Ｎ］の変動を第２図にそれぞれ
示す。
第２表より、従来法では５℃／分の昇熱速度し
か得られなかつたのに対し、本発明法では最大
12.5℃／分の高昇熱速度が得られた。また、昇熱
処理前後の［Mn］［Si］の成分変化率は10％以
下と有価成分ロスも抑制できた。さらに、第２図
より明らかなごとく、［Ｃ］［Ｐ］［Ｎ］につい
てもほとんど成分の変動は認められなかつた。
INDUSTRIAL APPLICATION FIELD This invention relates to a method for heating molten steel in a molten metal container, mainly a ladle, and more particularly, to a method for heating molten steel by adding Al to molten steel in a ladle and oxygen blowing. Prior Art In the steelmaking process, when molten steel in a ladle that has been refined in a refining furnace such as a converter is supplied to continuous casting, etc., or when ladle refining is performed, it is necessary to adjust the temperature of the molten steel. As a method of compensating for this molten steel temperature, for example, the following method is known. A method of adding an exothermic agent to molten steel in a ladle and blowing oxygen into it (Japanese Patent Application Laid-open Nos. 54-149313, 1982-89708, 1982-235506). A method of adding linear metal or alloy to molten steel in a ladle (Japanese Patent Publication No. 54-29163). To explain in more detail, the method involves adding exothermic agents such as Al and Si to the molten steel in a ladle, blowing inert gas from the bottom of the ladle and stirring the molten steel while oxygen blowing it to increase the temperature of the molten steel. This is the way to do it. In addition, a method for adding metals or alloys to molten steel is to introduce an inert gas from the bottom and stir the molten steel, while supplying oxygen from a top-blown immersion lance to a linear metal (stoichiometrically equivalent or more). In this method, aluminum wire, etc.) or alloy is fed into the lance, and is melted by contact with the molten steel at the lower end of the lance, thereby raising the temperature of the molten steel. Problems with the prior art However, in the conventional method described above, all of the stirring of molten steel is performed by injecting inert gas from the porous plug installed at the bottom of the ladle. This causes clogging of the plug, an increase in repair work, etc., and it is not possible to increase the stirring power by increasing the inert gas flow rate. Therefore, bottom-blowing stirring using a porous plug was unable to increase the rate of oxygen delivery and increase the rate of heating. This invention has been made in order to solve the above-mentioned conventional problems, and aims to propose a method for heating molten steel in a ladle that can increase the heating rate by increasing the stirring force of molten steel. Structure of the Invention A method for raising the temperature of molten steel in a ladle according to the present invention includes blowing an inert gas into the molten steel in a ladle using a bubbling lance immersed deeper than 1/2 of the distance between the molten steel surface and the bottom of the ladle. After stirring the slag and cutting off the slag by immersing a snorkel having a diameter smaller than the surface of the molten steel bath exposed by the plume generated at that time, a heat generating agent is added to the surface of the molten steel bath in the snorkel, and a top-blowing lance is used to cut the slag. It is characterized by oxygen blowing. Function: According to the method of stirring the molten steel by dipping the bubbling lance deeper than 1/2 of the distance between the surface of the molten steel and the bottom of the ladle and blowing inert gas into the molten steel in the ladle, the inert gas The flow rate can be increased compared to the conventional porous plug method. In other words, it becomes possible to blow in a large flow of inert gas and increase the stirring power of molten steel, thereby increasing the oxygen supply rate and the heating rate. The reason why the bubbling lance is immersed deeper than 1/2 of the distance between the molten steel surface and the bottom of the ladle is because if the molten steel surface is shallower than 1/2 of the distance between the bottom of the ladle, inert gas will not reach the vicinity of the bottom of the ladle. This is because stirring becomes insufficient. However, it is preferable to immerse the bubbling lance deeper than 2/3 to 3/4 of the distance between the surface of the molten steel and the bottom of the ladle. To avoid strong contact with the bottom of the ladle, set the distance between the bottom and the
It is necessary to take 100cm. In addition, by immersing in the molten steel a snorkel having a diameter smaller than the molten steel bath surface exposed by the plume generated by stirring the molten steel, it is possible to form a molten bath surface free of slag. By adding an exothermic agent to the surface of the molten steel bath, the efficiency of the reaction between the exothermic agent and the molten steel can be increased. This increase in reaction efficiency reduces loss of valuable components and oxides in the slag. Furthermore, since the molten steel is stirred by a bubbling lance, problems such as melting and clogging of the refractory of the porous plug and an increase in the number of repair man-hours can be solved. Specific Example Fig. 1 is a schematic diagram showing an embodiment of the method of this invention, in which 1 is a ladle, 2 is molten steel, 3 is a bubbling lance, 4 is an oxygen lance, 5 is a snorkel, 6 is a slag, and G 1 is an Ar , CO2 and other inert gases, G2 is oxygen gas. 8 is a dust collection hood. That is, the molten steel 2 melted in the melting furnace is transferred to the ladle 1, and during the molten steel, the distance between the molten steel surface and the bottom of the ladle is 1/1.
The molten steel 2 is stirred by blowing inert gas through the bubbling lance 3 which is immersed deeper than the molten steel 2. A plume generated by stirring the molten steel exposes the molten steel bath surface, and a snorkel 5 having a diameter smaller than the exposed molten steel bath surface 7 is immersed in the molten steel. This snorkel 5 is an immersion tube coated with refractory material. This shunorkel is attached to the molten steel bath surface 7.
By immersing the steel in water, the surrounding floating slag can be cut off to form a slag-free molten steel bath surface inside the snorkel. Thereafter, a heat generating agent is added onto the surface of the molten steel bath in the snorkel 5, and oxygen gas is blown in from the oxygen lance 4 lowered to a predetermined height to start oxygen blowing. The exothermic agent may be added in its entirety before oxygen blowing, or may be added in portions during blowing. After the oxygen blowing is completed, bubbling is continued for several minutes in order to further improve the cleanliness of the molten steel, and then the bubbling lance 3 is raised, and then the snorkel 5 is raised to complete the heat raising treatment. Example Using the equipment shown in Fig. 1, 160 tons of molten steel having the composition shown in Table 1 was placed in a ladle, and Al was added to the surface of the molten steel in the snorkel from the top of the ladle.
During molten steel, 4/5 to 4/5 of the distance between the molten steel surface and the bottom of the ladle.
Ar from a bubbling lance immersed in about 5/6
Oxygen blowing was carried out by blowing oxygen gas from an oxygen lance while stirring the molten steel. In addition, for comparison, heat treatment was performed using a conventional method (bottom-blowing stirring). The treatment conditions of this example are shown in Table 2, and the fluctuations in [C], [P], and [N] before and after the heating treatment are shown in FIG. 2, respectively. From Table 2, it can be seen that while the conventional method could only achieve a heating rate of 5°C/min, the method of the present invention achieved the maximum heating rate of 5°C/min.
A high heating rate of 12.5°C/min was obtained. In addition, the rate of change in [Mn] and [Si] components before and after the heat raising treatment was less than 10%, suppressing the loss of valuable components. Furthermore, as is clear from FIG. 2, almost no changes in the components of [C], [P], and [N] were observed.
【表】【table】
【表】
発明の効果
以上説明したごとく、この発明方法によれば、
不活性ガス流量を増加して溶鋼の撹拌力を増大で
きるので、送酸速度を上げて昇熱速度を上昇させ
ることができるとともに、有価成分ロスおよび低
級酸化物の低減もはかることができる。また、溶
鋼撹拌用不活性ガスは上吹浸漬ランスにより吹込
むので、ポーラスプラグ方式に比べ耐火物コスト
が安価につく上、溶鋼撹拌を安定して行なうこと
ができる。
したがつて、この発明は最近特に重要となつて
いる転炉での２次精錬の効果的実施のために必要
な溶鋼温度、溶解清浄性の補償に大きく寄与する
ものである。[Table] Effects of the invention As explained above, according to the method of this invention,
Since the stirring power of molten steel can be increased by increasing the flow rate of inert gas, the oxygen supply rate can be increased to increase the heating rate, and it is also possible to reduce loss of valuable components and lower oxides. In addition, since the inert gas for stirring molten steel is blown in by a top-blown immersion lance, the cost of refractories is lower than in the porous plug method, and the molten steel can be stirred stably. Therefore, this invention greatly contributes to compensation of molten steel temperature and melt cleanliness necessary for effective implementation of secondary refining in a converter, which has recently become particularly important.
第１図はこの発明の一実施例を示す概略図であ
る。第２図はこの発明の実施例における昇熱処理
前後の成分変動を示す図である。
１…取鍋、２…溶鋼、３…バブリングランス、
４…酸素ランス、５…シユノーケル、６…スラ
グ。
FIG. 1 is a schematic diagram showing an embodiment of the present invention. FIG. 2 is a diagram showing component fluctuations before and after heat treatment in an example of the present invention. 1... Ladle, 2... Molten steel, 3... Bubbling lance,
4...Oxygen lance, 5...Shunorkel, 6...Slag.
Claims (1)
吹込んで溶鋼を撹拌しながら酸素吹錬する取鍋内
溶鋼の昇熱方法において、取鍋内溶鋼中に溶鋼表
面と取鍋底面間距離の１／２より深く浸漬させた
バブリングランスにより不活性ガスを吹込んで溶
鋼を撹拌し、その時発生するプルームにより露出
された溶鋼浴面より小さい直径を有するシユノー
ケルを浸漬してスラグをカツトした後、前記シユ
ノーケル内の溶鋼浴面に発熱剤を添加して上吹ラ
ンスにて酸素吹錬を行うことを特徴とする取鍋内
溶鋼の昇熱方法。1. In a heating method for molten steel in a ladle, in which a heating agent is added to molten steel in a ladle and oxygen blowing is performed while stirring the molten steel by blowing an inert gas into the molten steel, After stirring the molten steel by blowing inert gas into it using a bubbling lance immersed deeper than 1/2 of the distance, the slag is cut by immersing a snorkel with a diameter smaller than the surface of the molten steel bath exposed by the plume generated at that time. A method for raising the temperature of molten steel in a ladle, characterized in that a heating agent is added to the surface of the molten steel bath in the snorkel and oxygen blowing is performed using a top blowing lance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21382687A JPS6456816A (en) | 1987-08-27 | 1987-08-27 | Heating method for molten steel in ladle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21382687A JPS6456816A (en) | 1987-08-27 | 1987-08-27 | Heating method for molten steel in ladle |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6456816A JPS6456816A (en) | 1989-03-03 |
| JPH0510406B2 true JPH0510406B2 (en) | 1993-02-09 |
Family
ID=16645665
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21382687A Granted JPS6456816A (en) | 1987-08-27 | 1987-08-27 | Heating method for molten steel in ladle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6456816A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0726402A (en) * | 1993-07-12 | 1995-01-27 | Sfim Srl | Preparation of pantyhose and semi-fabricated product |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR960002348B1 (en) * | 1991-10-03 | 1996-02-16 | 도요다 지도오샤 가부시끼가이샤 | Device for purifying exhaust of internal combustion engine |
| EP0598916B1 (en) * | 1992-06-12 | 1999-09-15 | Toyota Jidosha Kabushiki Kaisha | Exhaust emission control system for internal combustion engine |
| US5437153A (en) * | 1992-06-12 | 1995-08-01 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| JP2605553B2 (en) * | 1992-08-04 | 1997-04-30 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engine |
| JP2605556B2 (en) * | 1992-10-13 | 1997-04-30 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engine |
| US5473890A (en) * | 1992-12-03 | 1995-12-12 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
| JP2760251B2 (en) * | 1993-03-12 | 1998-05-28 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engine |
| KR100270117B1 (en) * | 1996-12-14 | 2000-10-16 | 이구택 | Temperature rising method of molten steel during degassing of molten steel |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54149313A (en) * | 1978-05-16 | 1979-11-22 | Ishikawajima Harima Heavy Ind Co Ltd | Elevated temperature refining method for molten steel |
| JPS6137912A (en) * | 1984-07-30 | 1986-02-22 | Nippon Steel Corp | Method for vacuum-refining molten steel |
| JPS61133307A (en) * | 1984-12-03 | 1986-06-20 | Ishikawajima Harima Heavy Ind Co Ltd | Refining method of molten steel |
| JPS61235506A (en) * | 1985-04-09 | 1986-10-20 | Nippon Steel Corp | Heating up method for molten steel in ladle |
-
1987
- 1987-08-27 JP JP21382687A patent/JPS6456816A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0726402A (en) * | 1993-07-12 | 1995-01-27 | Sfim Srl | Preparation of pantyhose and semi-fabricated product |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6456816A (en) | 1989-03-03 |
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