JPH0841521A - Ladle slag removal method - Google Patents
Ladle slag removal methodInfo
- Publication number
- JPH0841521A JPH0841521A JP18138094A JP18138094A JPH0841521A JP H0841521 A JPH0841521 A JP H0841521A JP 18138094 A JP18138094 A JP 18138094A JP 18138094 A JP18138094 A JP 18138094A JP H0841521 A JPH0841521 A JP H0841521A
- Authority
- JP
- Japan
- Prior art keywords
- slag
- molten steel
- ladle
- discharged
- lime nitrogen
- 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.)
- Withdrawn
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
(57)【要約】
【目的】 見掛けのスラグ容量を増加させて効率的にス
ラグを排出すること。
【構成】 転炉、電気炉で精錬された溶鋼１を取鍋２に
受鋼し、溶鋼中残存酸素を１００ｐｐｍ以上に調整し、
溶鋼の上方より炭素源を有する石灰窒素を発泡剤４とし
て添加し、鋼中あるいはスラグ中の酸素と石灰窒素の炭
素を反応させ微細ＣＯ気泡を形成させてスラグをフォー
ミングさせ、取鍋２を傾斜させ、溶鋼面上のフォーミン
グ・スラグ５を取鍋１の上縁からオーバーフロー状に排
出させる。
(57) [Summary] [Purpose] To increase the apparent slag capacity and efficiently discharge slag. [Constitution] Molten steel 1 refined in a converter and an electric furnace is received in a ladle 2 and the residual oxygen in the molten steel is adjusted to 100 ppm or more,
Lime nitrogen having a carbon source is added as a foaming agent 4 from above the molten steel, oxygen in the steel or slag and carbon of lime nitrogen are reacted to form fine CO bubbles to form the slag, and the ladle 2 is tilted. Then, the forming slag 5 on the molten steel surface is discharged from the upper edge of the ladle 1 in an overflow form.
Description
【０００１】[0001]
【産業上の利用分野】本発明は、製鋼操業を実施するに
際して製品欠陥の原因となる取鍋溶鋼面上のスラグを効
率的に排出する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently discharging slag on the molten steel surface of a ladle, which causes a product defect when carrying out a steelmaking operation.
【０００２】[0002]
【従来の技術】転炉、電気炉などで精錬した場合に発生
するスラグは、二次精錬における介在物の原因あるいは
復燐、復硫の原因となり製品欠陥を招く。このため、こ
の取鍋溶鋼面上のスラグは取り除く必要がある。2. Description of the Related Art Slag generated when refining in a converter, an electric furnace, or the like causes the inclusions in the secondary refining or causes rephosphorization and re-sulfurization, resulting in product defects. Therefore, it is necessary to remove the slag on the molten steel surface of the ladle.
【０００３】そこで、従来からスラグ排出のために種々
の検討が行われており、機械的にスラグを掻き出すドラ
ッガー排滓法、あるいは、空気の負圧によりスラグを吸
い取るスラグ吸引法などが提案されている。Therefore, various studies have been conducted to discharge slag, and a dragger slag method for mechanically scraping slag or a slag suction method for sucking slag by negative pressure of air has been proposed. There is.
【０００４】たとえば、特開昭６１−２４６３０５号公
報は、ドラッガー排滓法の一例を示しており、同公報に
は、溶融金属を収容した取鍋を所定角度に傾斜させ、浸
漬ランスを溶湯に浸漬させてガス吹込みを行って取鍋内
の溶融金属に旋回流れを形成し、取鍋の一端にスラグを
集積させ、スラグ掻出し装置を回転させて連続してスラ
グ排出を実施する溶融金属のスラグ除去装置が開示され
ている。For example, Japanese Laid-Open Patent Publication No. 61-246305 shows an example of the dragger slag method, in which the ladle containing the molten metal is tilted at a predetermined angle and the immersion lance is used as the molten metal. Molten metal that is immersed and blows gas to form a swirling flow in the molten metal in the ladle, accumulates slag at one end of the ladle, and rotates the slag scraping device to continuously discharge slag. Slag removing device is disclosed.
【０００５】また、特開昭６１−１６５５８７号公報
は、スラグ吸引法の一例を示しており、同公報には、気
体吹込ノズルから高速流体導管に高速気体を流すことに
よって働く導管内の負圧を用いて、スラグ上に位置した
スラグ吸引管で取鍋スラグを吸引除去するスラグ吸引装
置が開示されている。Further, Japanese Patent Application Laid-Open No. 61-165587 discloses an example of a slag suction method, in which negative pressure in a conduit which works by flowing a high-speed gas from a gas injection nozzle to a high-speed fluid conduit. There is disclosed a slag suction device which sucks and removes ladle slag with a slag suction tube located on the slag.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、上記特
開昭６１−２４６３０５号公報に記載の装置において
は、スラグ排出設備として浸漬ランスおよびスラグ掻出
し装置を要するため設備コストが高くなるという問題が
ある。また、スラグ排出量を増加させるためには溶鋼自
体も排出させることになるため、溶鋼歩留が悪化すると
いう問題がある。また、スラグは回転するパドル状の掻
出し板により連続的に排出されるが、転炉など一次精錬
設備から取鍋への流出スラグは、その厚みが３０ｍｍ〜
６０ｍｍ程度であり比較的薄いので、上述した機械的な
排滓法では１枚の掻出し板当たりの排出量に限度があ
り、また、回転速度にも限度があるので、効率が悪いと
いう問題がある。すなわち、この機械的にスラグを排出
する方法は排出能力が低く、またスラグの排出に長時間
を要するため、溶鋼の温度低下を招くという不都合があ
る。However, in the apparatus described in Japanese Patent Laid-Open No. 61-246305, there is a problem that the equipment cost increases because the immersion lance and the slag scraping apparatus are required as the slag discharging equipment. . Further, in order to increase the slag discharge amount, the molten steel itself is also discharged, so that there is a problem that the molten steel yield is deteriorated. Further, the slag is continuously discharged by the rotating paddle-shaped scraping plate, but the thickness of the slag flowing out from the primary refining equipment such as a converter to the ladle is 30 mm ~
Since it is about 60 mm and is relatively thin, the mechanical slag method described above has a limit to the discharge amount per scraping plate, and also has a limit to the rotation speed, which causes a problem of poor efficiency. is there. That is, this method of mechanically discharging the slag has a low discharging capability, and since it takes a long time to discharge the slag, there is a disadvantage that the temperature of the molten steel is lowered.
【０００７】また、特開昭６１−１６５５８７号公報に
記載のスラグ吸入設備は、負圧を発生させるための特別
な機構を必要とするので設備費が高く、また、スラグ流
動性が悪い場合はスラグ排出効果が低いという問題があ
る。また、スラグ排出効果を強化することを目的とし
て、スラグ吸入管を溶鋼面直上まで低下させた場合は、
吸入管の溶融、あるいは地金付きが発生し、溶鋼吸い込
みによる溶鋼歩留の悪化と処理時間延長に伴う溶鋼温度
の低下が発生するという問題がある。Further, the slag suction equipment described in Japanese Patent Laid-Open No. 165587/61 requires a special mechanism for generating a negative pressure, so that the equipment cost is high and when the slag fluidity is poor. There is a problem that the slag discharge effect is low. Also, if the slag suction pipe is lowered to just above the molten steel surface in order to strengthen the slag discharge effect,
There is a problem that the suction pipe is melted or metal is attached to the suction pipe, the molten steel yield is deteriorated by sucking the molten steel, and the molten steel temperature is lowered due to extension of the processing time.
【０００８】そこで本発明は、見掛けのスラグ容量を増
加させて効率的にスラグを排出することを目的とする。[0008] Therefore, an object of the present invention is to increase the apparent slag capacity and efficiently discharge the slag.
【０００９】[0009]
【課題を解決するための手段】転炉、電気炉などの一次
精錬で溶製した溶鋼を、未脱酸出鋼あるいは二次精錬で
酸素負荷を行い、溶鋼残存酸素を所定値に制御する。そ
して、スラグ排出場所で取鍋スラグ上に炭素源を有する
石灰窒素を添加し、鋼中あるいはスラグ中の酸素と石灰
窒素の炭素を反応させ微細ＣＯ気泡を形成させてスラグ
をフォーミングさせ、溶鋼鍋を傾斜させ溶鋼面上のフォ
ーミング・スラグをオーバーフロー状に排出させる。[Means for Solving the Problems] Molten steel produced by primary refining such as a converter or an electric furnace is subjected to oxygen load by undeoxidized steel or secondary refining to control residual oxygen in the molten steel to a predetermined value. Then, lime nitrogen having a carbon source is added on the ladle slag at the slag discharge place, oxygen in the steel or slag is reacted with the carbon of lime nitrogen to form fine CO bubbles, and the slag is formed to form a molten steel ladle. The forming slag on the molten steel surface is discharged like an overflow.
【００１０】この際、フォーミング・スラグをドラッガ
ー排滓機を用いて除去すると更に効率は向上する。At this time, if the forming slag is removed by using a dragger slag machine, the efficiency is further improved.
【００１１】本発明の方法は、溶鋼酸素と添加フラック
スとのガス化反応（Ｃ＋Ｏ→ＣＯ）によるスラグ・フォ
ーミングを利用したものであり、反応時間は短く、ま
た、Ｃ＋Ｏ→ＣＯは発熱反応であり温度降下も抑制され
る。The method of the present invention utilizes slag forming by gasification reaction (C + O → CO) of molten steel oxygen and added flux, the reaction time is short, and C + O → CO is an exothermic reaction. The temperature drop is also suppressed.
【００１２】発泡剤として使用するフラックスは、石灰
窒素などの炭素源を有する溶鋼より比重が小さく、スラ
グとほぼ同等の比重を有したものであり、スラグ中に混
在する特性のものが必要である。The flux used as a foaming agent has a specific gravity smaller than that of molten steel having a carbon source such as lime nitrogen and has a specific gravity almost equal to that of slag, and it is necessary that the flux be mixed in the slag. .
【００１３】なお、コークス粉などでは、スラグとの濡
れ性が悪い炭素が、発生したＣＯ気泡を合体・破泡する
ため、微細気泡の形成が困難であり当初目的を達成でき
ない。In coke powder and the like, carbon, which has poor wettability with slag, coalesces and breaks the generated CO bubbles, so that it is difficult to form fine bubbles and the initial purpose cannot be achieved.
【００１４】[0014]
【作用】本発明においては、排出すべきスラグの物性を
考慮し、スラグ自体の物性を排滓に適したものとして排
滓効率を改善する。In the present invention, the physical properties of the slag to be discharged are taken into consideration, and the physical properties of the slag itself are made suitable for the slag, and the slag efficiency is improved.
【００１５】本発明によるスラグ除去の作業フローを図
１に示す。A work flow for removing slag according to the present invention is shown in FIG.
【００１６】転炉、電気炉などで酸化精錬された溶鋼１
を取鍋２に受鋼し（同図（ａ）参照）、溶存酸素１００
ｐｐｍ以上でスラグの比重と同等の石灰窒素を、上方あ
るいはスラグ３中に発泡剤４として添加する（同図
（ｂ）参照）。溶存酸素の濃度は、一次精錬で溶製した
溶鋼を、未脱酸出鋼あるいは二次精錬で酸素負荷を行な
うことにより調整する。Molten steel 1 oxidatively refined in a converter, electric furnace, etc.
Ladle 2 was steel-steeled (see (a) in the figure) and dissolved oxygen 100
Lime nitrogen, which is equal to or more than the specific gravity of slag in ppm or more, is added above or in the slag 3 as the foaming agent 4 (see FIG. 2B). The concentration of dissolved oxygen is adjusted by subjecting molten steel produced by primary refining to undeoxidized steel or by performing oxygen loading in secondary refining.
【００１７】スラグと混合した石灰窒素は、ＣａＣＮ→
ＣａＯ＋ＣＯ＋１／２Ｎ2 なる分解反応でガスを発生す
る。この反応は、スラグ３と１００ｐｐｍ以上の溶存酸
素を有する溶鋼１の界面で優先的に進行して微細なＣＯ
気泡を形成して取鍋スラグをフォーミングさせる。これ
により、見掛け比重の小さいフォーミング・スラグ５と
なり、スラグの容量が増加する（同図（ｃ）参照）。た
とえば、処理前のスラグ厚６０ｍｍが３〜１０倍程度ま
で増加する。なおこのとき、溶存酸素が１００ｐｐｍよ
りも少ない場合には、ＣａＣＮの分解反応で生成するＣ
とのＣＯ反応が不良となるためスラグフォーミングが充
分なされず、添加したＣａＣＮの溶鋼への溶け込みで溶
鋼中の［Ｃ］と［Ｎ］が高くなるという不都合がある。Lime nitrogen mixed with slag is CaCN →
A gas is generated by the decomposition reaction of CaO + CO + 1 / 2N 2 . This reaction preferentially proceeds at the interface between the slag 3 and the molten steel 1 having dissolved oxygen of 100 ppm or more, and fine CO
Form bubbles to form ladle slag. As a result, the forming slag 5 having a small apparent specific gravity is formed, and the capacity of the slag is increased (see FIG. 7C). For example, the slag thickness of 60 mm before processing increases to about 3 to 10 times. At this time, when the dissolved oxygen is less than 100 ppm, C generated by the decomposition reaction of CaCN
Since the CO reaction with and becomes poor, slag forming is not sufficient, and [C] and [N] in the molten steel become high due to the dissolution of the added CaCN into the molten steel.
【００１８】次に、取鍋２を傾けることにより（同図
（ｄ）参照）、溶鋼面上のフォーミング・スラグ５は、
取鍋２の上縁からオーバーフロー状に排出される。この
とき、スラグの厚みは、元の厚みに比べて厚くなってい
るので、溶鋼面の高さとオーバーフロー側の取鍋２の上
縁との距離が同じであるとすると、フォーミングされな
いスラグを排出する場合に比較して、排出されるスラグ
の割合が増加する。このようにスラグの容量が増加した
状態でスラグを排出することにより、排滓効率を高める
ことができる。Next, by tilting the ladle 2 (see FIG. 2D), the forming slag 5 on the molten steel surface is
It is discharged like an overflow from the upper edge of the ladle 2. At this time, since the thickness of the slag is thicker than the original thickness, assuming that the height of the molten steel surface and the upper edge of the ladle 2 on the overflow side are the same, the slag that is not formed is discharged. Compared to the case, the proportion of slag discharged increases. By discharging the slag in the state where the capacity of the slag is increased in this way, the slag efficiency can be improved.
【００１９】また、フォーミング・スラグ５を、駆動ロ
ール６ａと従動ロール６ｂに巻かれた無端ベルト６ｃ上
に多数の掻取り板６ｄが設けられようなドラッガー排滓
機６を使用して排出すれば、更に効率的に排滓できる。
すなわち、掻き取り板６ｄの大部分の面積を使用してス
ラグを排出することができるので、掻き取り板６ｄの１
枚当たりの排出量を増やすことができる。Further, if the forming slag 5 is discharged by using a dragger waste shaving machine 6 in which a large number of scraping plates 6d are provided on an endless belt 6c wound around a driving roll 6a and a driven roll 6b, , Can be more efficiently discharged.
That is, since most of the area of the scraping plate 6d can be used to discharge the slag, the scraping plate 6d is
Emissions per sheet can be increased.
【００２０】[0020]
【実施例】発泡剤として石灰窒素を溶鋼に添加した場合
の試験結果を表１に示す。また、比較例として、コーク
ス粉とＣａＣＯ3 をそれぞれ添加した場合の試験結果も
示す。[Examples] Table 1 shows the test results when lime nitrogen was added to molten steel as a foaming agent. Further, as a comparative example, the test results when coke powder and CaCO 3 are added are also shown.
【００２１】また、本発明の効果を表２に示す。Table 2 shows the effects of the present invention.
【００２２】[0022]
【表１】 [Table 1]
【表２】 表１から判るように、石灰窒素を添加し、且つ、溶鋼中
の溶存酸素を１００ｐｐｍ以上とした場合には、スラグ
を良好にフォーミングさせることができたが、それ以外
の場合には、良好なスラグ・フォーミングは実現できな
かった。[Table 2] As can be seen from Table 1, when lime nitrogen was added and the dissolved oxygen in the molten steel was 100 ppm or more, the slag could be formed well, but in other cases, it was excellent. Slug forming could not be realized.
【００２３】コークス粉を添加した場合、溶鋼中の溶存
酸素を１００ｐｐｍ以上とした場合には、気泡は発生す
るが、コークス粉とスラグの濡れ性が悪く、ＣＯ気泡が
合体して大きな泡となったり、泡が壊れたりするため、
スラグ・フォーミングに必要な微細気泡の形成が困難で
ある。When coke powder is added and dissolved oxygen in the molten steel is 100 ppm or more, bubbles are generated, but the coke powder and the slag have poor wettability, and CO bubbles coalesce into a large bubble. Or the bubbles may break,
It is difficult to form fine bubbles necessary for slag forming.
【００２４】また、ＣａＣＯ3 を添加した場合、その比
重がスラグに比べて小さいため、ＣａＣＯ3 の上方に偏
在するため溶鋼からの熱を充分受けることができず、溶
鋼中の溶存酸素を１００ｐｐｍ以上とした場合でも、Ｃ
Ｏガスの発生量が少ない。When CaCO 3 is added, since its specific gravity is smaller than that of slag, it is unevenly distributed above CaCO 3 and cannot sufficiently receive heat from the molten steel, and the dissolved oxygen in the molten steel is 100 ppm or more. Even if
The amount of O gas generated is small.
【００２５】上述の試験結果から判るように、発泡剤と
しては、スラグ物性に近く、コークス粉のような破泡効
果がなく、ガス発生量の大きい石灰窒素が最も良好であ
ることが判る。As can be seen from the above-mentioned test results, it is found that the foaming agent is lime nitrogen which is close to the physical properties of slag, does not have a defoaming effect like coke powder, and has a large gas generation amount.
【００２６】[0026]
【発明の効果】本発明は、スラグ中に発泡剤を添加して
見掛けのスラグ量を増加させた状態で取鍋を傾動させて
スラグを排出しているので以下の効果を奏する。INDUSTRIAL APPLICABILITY The present invention has the following effects because the ladle is tilted and the slag is discharged while the apparent amount of slag is increased by adding the foaming agent to the slag.
【００２７】（１）取鍋内の精錬スラグの排滓を特別な
排滓設備なしに効率的に行なうことが可能となる。(1) The refining slag in the ladle can be efficiently discharged without any special waste equipment.
【００２８】（２）取鍋内の精錬スラグ排滓を迅速に、
溶鋼ロスなく、且つ温度降下なしに行なうことが可能と
なる。(2) Promptly remove the refined slag waste from the ladle,
It is possible to carry out without loss of molten steel and without temperature drop.
【図１】 本発明によるスラグ除去の作業フローを示す
図である。FIG. 1 is a diagram showing a work flow of slag removal according to the present invention.
１…溶鋼、２…取鍋、３…スラグ、４…発泡剤、５…フ
ォーミング・スラグ、６…ドラッガー排滓機1 ... Molten steel, 2 ... Ladle, 3 ... Slag, 4 ... Foaming agent, 5 ... Forming slag, 6 ... Dragger slag machine
Claims (1)
あるいはスラグ中の酸素と前記フラックス中の炭素を反
応させ微細ＣＯ気泡を形成させてスラグをフォーミング
させ、 取鍋を傾斜させ、溶鋼面上のフォーミング・スラグを取
鍋の上縁からオーバーフロー状に排出させる取鍋スラグ
除去方法。1. A refined molten steel is received in a ladle, the residual oxygen in the molten steel is adjusted to 100 ppm or more, and lime nitrogen having a carbon source is added from above the molten steel to obtain oxygen in the steel or slag. A ladle slag removing method in which carbon in the flux is reacted to form fine CO bubbles to form a slag, the ladle is tilted, and the forming slag on the molten steel surface is discharged in an overflow form from the upper edge of the ladle. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18138094A JPH0841521A (en) | 1994-08-02 | 1994-08-02 | Ladle slag removal method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18138094A JPH0841521A (en) | 1994-08-02 | 1994-08-02 | Ladle slag removal method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0841521A true JPH0841521A (en) | 1996-02-13 |
Family
ID=16099723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18138094A Withdrawn JPH0841521A (en) | 1994-08-02 | 1994-08-02 | Ladle slag removal method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0841521A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001029271A1 (en) * | 1999-10-18 | 2001-04-26 | Norsk Hydro Asa | Method and use of calcium nitrate for foaming of steel-making slags |
| KR20110050197A (en) * | 2009-11-06 | 2011-05-13 | 주식회사 포스코 | High efficiency slag exclusion method |
| CN102296144A (en) * | 2010-06-25 | 2011-12-28 | 鞍钢股份有限公司 | A method for removing slag from molten steel |
| CN109207672A (en) * | 2018-12-03 | 2019-01-15 | 南阳汉冶特钢有限公司 | A kind of production method of Slagoff method and ultra-low phosphoretic steel in ultra-low phosphoretic steel production process |
| CN116926272A (en) * | 2023-04-27 | 2023-10-24 | 河钢乐亭钢铁有限公司 | Method for improving ladle slag modification effect |
-
1994
- 1994-08-02 JP JP18138094A patent/JPH0841521A/en not_active Withdrawn
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001029271A1 (en) * | 1999-10-18 | 2001-04-26 | Norsk Hydro Asa | Method and use of calcium nitrate for foaming of steel-making slags |
| KR20110050197A (en) * | 2009-11-06 | 2011-05-13 | 주식회사 포스코 | High efficiency slag exclusion method |
| CN102296144A (en) * | 2010-06-25 | 2011-12-28 | 鞍钢股份有限公司 | A method for removing slag from molten steel |
| CN109207672A (en) * | 2018-12-03 | 2019-01-15 | 南阳汉冶特钢有限公司 | A kind of production method of Slagoff method and ultra-low phosphoretic steel in ultra-low phosphoretic steel production process |
| KR20200070213A (en) * | 2018-12-03 | 2020-06-17 | 난양 한예 스페셜 스틸 코., 엘티디 | Method for removing slag during production process of ultra-low steel and production method of ultra-low steel |
| US11718885B2 (en) | 2018-12-03 | 2023-08-08 | Nanyang Hanye Special Steel Co., Ltd | Slag discharging method in process of producing ultra-low phosphorus steel and method for producing ultra-low phosphorus steel |
| CN116926272A (en) * | 2023-04-27 | 2023-10-24 | 河钢乐亭钢铁有限公司 | Method for improving ladle slag modification effect |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5195737B2 (en) | Hot metal desulfurization method | |
| JPH0841521A (en) | Ladle slag removal method | |
| TWI816422B (en) | Refining method of molten steel | |
| EP4339303B1 (en) | Molten steel refining method | |
| EP4339302B1 (en) | Method for refining molten steel | |
| KR100270109B1 (en) | Nitrogen removal method in molten steel using vacuum tank | |
| JPH05195043A (en) | Method for injecting flux for refining molten metal and device therefor | |
| JP2808197B2 (en) | Vacuum refining of molten steel using large diameter immersion tube | |
| JP2003166009A (en) | Hot metal desulfurization method | |
| JP6416634B2 (en) | Desiliconization and desulfurization methods in hot metal ladle | |
| RU2823106C2 (en) | Method of refining molten steel | |
| TWI816421B (en) | Refining method of molten steel | |
| JPS63114918A (en) | Production of flow sulfur clean steel | |
| SU1135773A1 (en) | Method for batch vacuum treatment of steel | |
| JPH09287016A (en) | Stainless steel melting method | |
| JPH06927B2 (en) | Agitating and refining method desulfurization method by repeatedly sucking and discharging molten steel | |
| JP3922189B2 (en) | Ladle refining method for molten steel | |
| SU929713A1 (en) | Method for treating molten steel | |
| JP6238019B2 (en) | Hot metal desulfurization method with less recuperation | |
| JPH08120324A (en) | Apparatus and method for vacuum refining molten steel | |
| SU1073298A1 (en) | Apparatus for recirculating evacuation of metal | |
| JPH05320739A (en) | Vacuum refining method | |
| JP3282530B2 (en) | Method for producing high cleanliness low Si steel | |
| JP3290794B2 (en) | Molten steel refining method under reduced pressure | |
| JP2003342626A (en) | Rotating stirrer for molten metal and method for desulfurizing molten metal using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20011002 |