JPH08143925A - Method for desiliconizing molten iron - Google Patents

Method for desiliconizing molten iron

Info

Publication number
JPH08143925A
JPH08143925A JP30840294A JP30840294A JPH08143925A JP H08143925 A JPH08143925 A JP H08143925A JP 30840294 A JP30840294 A JP 30840294A JP 30840294 A JP30840294 A JP 30840294A JP H08143925 A JPH08143925 A JP H08143925A
Authority
JP
Japan
Prior art keywords
hot metal
molten iron
level
value
ladle
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.)
Granted
Application number
JP30840294A
Other languages
Japanese (ja)
Other versions
JP3232922B2 (en
Inventor
Takafumi Kishu
崇文 旗手
Akio Shimomura
昭夫 下村
Iwao Okochi
巌 大河内
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Engineering Corp
Original Assignee
NKK Corp
Nippon Kokan Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NKK Corp, Nippon Kokan Ltd filed Critical NKK Corp
Priority to JP30840294A priority Critical patent/JP3232922B2/en
Publication of JPH08143925A publication Critical patent/JPH08143925A/en
Application granted granted Critical
Publication of JP3232922B2 publication Critical patent/JP3232922B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Abstract

PURPOSE: To execute the stable desiliconizing treatment at a low cost by measuring slag level while receiving molten iron adding desiliconizing agent into a molten iron ladle and charging foaming inhibitor into the molten iron ladle based on the difference between this measured value and the molten iron wt. value in the molten iron ladle. CONSTITUTION: The molten iron 3 is supplied into a tilting trough 4 from a blast furnace 1 through a main trough 2, and while injecting the desiliconizing agent 11 from an injecting lance 9, the molten iron is received into the molten iron ladle 5. The slag level L1 in the molten iron ladle 5 is measured with a microwave level meter 16 and always monitored. Further, the molten iron wt. in the molten iron ladle 5 is measured with a weigher 15 and the molten iron level value L2 is calculated based on the shape of the molten iron ladle 5 from this value. When the value of L1 -L2 exceeds a prescribed threshold value, the foaming inhibitor 14 is charged and then, when the slag level L1 reaches the fixed value and the received molten iron level reaches the regulated value or higher, the receiving of the molten iron is completed. By this method, the consumption of the foaming inhibitor 14 is made to be suitable and the desiliconizing treatment of the molten iron 3 is stably executed.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、脱珪剤が添加された溶
銑を溶銑鍋に受銑しながら、スラグのフォーミングを制
御しながら溶銑の脱珪処理をする方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of performing desiliconization treatment of hot metal while controlling the forming of slag while receiving hot metal containing a desiliconizing agent into a hot metal ladle.

【0002】[0002]

【従来の技術】一般に、高炉溶銑は転炉等での製鋼処理
の前に脱珪処理が行われている。この脱珪処理は、例え
ば溶銑中のSi0.25〜0.5wt%を0.1wt%
以下とする処理である。この脱珪処理は、例えばミルス
ケールを高炉鋳床における傾注樋を通過する溶銑に添加
することにより行なわれる。脱珪反応は溶銑が溶銑鍋に
注入された後も進行し、溶銑鍋中でいわゆるスラグのフ
ォーミングが起こることが多い。
2. Description of the Related Art Generally, blast furnace hot metal is subjected to desiliconization treatment before steelmaking treatment in a converter or the like. This desiliconization treatment is performed, for example, by adding Si 0.25 to 0.5 wt% in the hot metal to 0.1 wt%
The processing is as follows. This desiliconization treatment is carried out, for example, by adding mill scale to the hot metal passing through the inclined trough in the blast furnace casting floor. The desiliconization reaction proceeds even after the hot metal is poured into the hot metal ladle, and so-called slag forming often occurs in the hot metal ladle.

【0003】このスラグのフォーミング(以下、単にフ
ォーミングという)とは、脱珪剤中のFe23 等が溶
銑及びスラグと反応して生成したCOガスがスラグを泡
立て、その結果、スラグレベルが上昇する現象である。
スラグレベルが上昇すると、その分だけ溶銑鍋の受銑能
力が低下するために、後工程の排滓処理や溶銑鍋の効率
的な運用に支障が生じる。また、フォーミングによりス
ラグや溶銑が鍋から溢れると、周辺の設備の運用にも支
障をきたす。
This slag forming (hereinafter simply referred to as "forming") means that CO gas produced by the reaction of Fe 2 O 3 and the like in the desiliconizing agent with the hot metal and the slag foams the slag, resulting in a slag level of It is a rising phenomenon.
When the slag level rises, the ability of the hot metal ladle to receive the iron decreases, and this causes a hindrance to post-process slag treatment and efficient operation of the hot metal ladle. In addition, if slag or hot metal overflows from the pot due to forming, it will interfere with the operation of the surrounding equipment.

【0004】また、溶銑鍋から溢れるほどでなくても、
フォーミングが発生するため予定の脱珪剤投入量より少
ない量を投入し場合、所望のレベルまで溶銑中のSiを
除去できず、後工程の成分調整に支障をきたすことがあ
る。そのため、種々のフォーミング抑制方法や、フォー
ミング抑制剤が提案されている。
In addition, even if it does not overflow the hot metal ladle,
If a smaller amount than the planned amount of the desiliconizing agent is added due to the occurrence of forming, Si in the hot metal cannot be removed to a desired level, which may hinder the subsequent component adjustment. Therefore, various forming suppressing methods and forming inhibitors have been proposed.

【0005】例えば、特開平2−301507号公報
は、混鋳車におけるスラグレベルの変化速度を監視し、
変化速度が増加したときフォーミングの発生を検知し、
沈静時の注入レベルから受銑完了レベルを推定するフォ
ーミング検知方法を開示する。
For example, Japanese Patent Laid-Open No. 2-301507 discloses that the rate of change of slag level in a mixed casting vehicle is monitored,
Detects the occurrence of forming when the rate of change increases,
A forming detection method for estimating a pig iron completion level from a sedation injection level is disclosed.

【0006】しかし、傾注樋の詰まりなどの外的要因で
溶銑注入量が減ったときに、フォーミングが発生しても
スラグレベルの変化速度は増加しないので、例えば傾注
樋の傾きから受銑速度を推定したとしても、フォーミン
グを見逃す可能性があり、受銑レベルの目標値からズレ
が生ずる。当然のことながら、途中で予想外の理由で受
銑速度が変化すれば予め推定していた受鋳量の増加曲線
が変わり、目標の受銑量が確保できる保障はない。
However, when the amount of molten pig iron injected is reduced due to external factors such as clogging of the slant gutter, the rate of change of the slag level does not increase even if forming occurs. Even if estimated, there is a possibility that the forming may be missed, and a deviation occurs from the target value of the pig iron level. As a matter of course, if the pig iron receiving speed changes during the course of the process, the increase curve of the casting amount estimated in advance changes and there is no guarantee that the target pig iron receiving amount can be secured.

【0007】また、スラグの沈静時の注入レベルから受
銑完了を予測するといっても、フォーミングが沈静する
周期が操業条件等により定まらず、数十秒から数分にな
ることもある。そのように沈静の周期が長い場合では、
受銑完了レベルの決定にも時間がかかり、短時間でのス
ムーズな操業に支障をきたす。また、脱珪剤を連続的に
多量投入した場合、沈静の周期が長くなる傾向にあり、
スラグの沈静時の注入レベルから受銑の完了を予測する
ことは困難である。
Further, even if the completion of pig iron reception is predicted from the injection level at the time of slag settling, the period at which the forming is settled is not determined depending on the operating conditions or the like, but may be several tens of seconds to several minutes. If the sedation cycle is long,
It also takes time to determine the completion level of pig iron, which hinders smooth operation in a short time. In addition, when a large amount of desiliconizing agent is continuously added, the sedation cycle tends to be long,
It is difficult to predict the completion of pig iron from the injection level during slag sedation.

【0008】つまり、上記方法では、単にスラグレベル
あるいはスラグレベルの変化速度から溶銑レベルあるい
はフォーミング厚さを予測しているにすぎず、途中で傾
注樋の詰まり等の予想外の理由により受銑速度が変化す
ると誤差が生じ、正確な予測は得られない。さらに、沈
静時から沈静時までの周期が数秒程度の場合は、もちろ
ん問題なく受銑可能だが、長時間の場合、例えば数分以
上あるいは沈静が全く起こらなければフォーミング厚さ
の正確な予測には不十分である。
That is, in the above method, the hot metal level or the forming thickness is simply predicted from the slag level or the changing speed of the slag level. If changes occur, an error will occur and an accurate prediction cannot be obtained. Furthermore, if the period from sedation to sedation is about a few seconds, of course, it can be accepted without problems, but if it is a long time, for example, more than a few minutes or if sedation does not occur at all, accurate forming thickness prediction is not possible. Is insufficient.

【0009】また、特開平3−281712号公報は、
マイクロ波レベル計を用いるスラグレベルの計測方法を
開示するが、この方法はフォーミングの定性的な判断を
可能とするが、フォーミング厚さの定量的な判断により
抑制剤投入量の調整を可能にするまではいたらない。す
なわち、単にマイクロ波レベル計によりスラグレベルあ
るいはスラグレベルの変化速度を捕らえただけでは、フ
ォーミングの厚さを把握することは不可能である。
Further, Japanese Patent Laid-Open No. 3-281712 discloses that
Disclosed is a slag level measuring method using a microwave level meter, which enables qualitative judgment of forming, but enables quantitative adjustment of the forming thickness to adjust the amount of inhibitor input. I'm sorry. That is, it is impossible to grasp the thickness of the forming by merely capturing the slag level or the changing speed of the slag level with the microwave level meter.

【0010】また、特開昭49−5830号公報、特開
昭51−29303号公報は、重量計を用いてスラグレ
ベルを測定する方法を開示している。これらの方法は受
銑重量を検出しつつ、受銑量の制御を行うものである。
しかし、スラグのフォーミングは泡立ち現象であるた
め、重量変化を伴わず、従って、受銑重量の検出によっ
てフォーミング厚さを把握し、受銑レベルの制御を行う
ことはできない。フォーミングは溶銑鍋内に混入したス
ラグが泡立つ現象であって重量の変化を伴わないため、
重量変化の検出による方法ではフォーミングを検知する
ことは不可能だからである。
Further, JP-A-49-5830 and JP-A-51-29303 disclose methods for measuring the slag level using a weight scale. These methods control the amount of pig iron while detecting the weight of pig iron.
However, since the slag forming is a foaming phenomenon, there is no change in weight, and therefore the forming thickness cannot be grasped by detecting the weight of the pig iron and the pig iron level cannot be controlled. Forming is a phenomenon that the slag mixed in the hot metal ladle foams and does not change the weight,
This is because it is impossible to detect the forming by the method of detecting the weight change.

【0011】さらに、スラグレベルあるいは受銑レベル
を測定する方法としては、特開平4−295725号公
報に記載されるように、トピードカーの胴部両側の所定
位置にγ線等の発生源と検出器とを設け、γ線の透過量
からレベル状態を推定するものである。しかし、フォー
ミング厚さの急激な変化を捕らえることはできない。
Further, as a method for measuring the slag level or the pig iron level, as described in Japanese Patent Application Laid-Open No. 4-295725, a source and detector of γ-rays and the like are provided at predetermined positions on both sides of the body of the topedo car. Is provided, and the level state is estimated from the transmission amount of γ-rays. However, it is impossible to catch a sudden change in the forming thickness.

【0012】また、以上のような受銑方法の他に、フォ
ーミング生成時の泡立ち防止剤(フォーミング抑制剤)
が特開昭62−136512号公報や特開昭62−18
0713号公報において提案されている。これら抑制剤
は、いずれも主成分として金属アルミニウム粉末、炭素
質粉末、アルミナ、シリカ等とを配合したものであっ
て、フォーミングが発生したときに、その抑制を図るも
のである。
In addition to the pig iron receiving method as described above, a foaming inhibitor (forming inhibitor) at the time of forming is formed.
JP-A-62-136512 and JP-A-62-18
No. 0713 is proposed. Each of these inhibitors is a mixture of metallic aluminum powder, carbonaceous powder, alumina, silica and the like as a main component, and is intended to suppress the forming when it occurs.

【0013】しかし、フォーミングが発生したときに、
上記の抑制剤を添加して抑制する方法は極めて効果的で
あるが、2つの問題を有する。第1点は、抑制剤として
不必要な成分も混入し、その後の転炉その他の処理が煩
雑になること、第2点は、通常、安全をみて多めに投射
する傾向があり、抑制剤が極めて高価であることから経
済性が大幅に損なわれることである。
However, when forming occurs,
Although the above method of adding and suppressing the inhibitor is extremely effective, it has two problems. The first point is that unnecessary components are mixed in as an inhibitor, and the subsequent converter and other treatments become complicated, and the second point is that there is a tendency to project a large amount in view of safety. It is extremely expensive, and economic efficiency is greatly impaired.

【0014】[0014]

【発明が解決しようとする課題】本発明は、前述した従
来技術の欠点を解消を目的とし、具体的には、溶銑鍋へ
の受銑中、発生するフォーミングとその厚さを精度良く
検知することにより、フォーミング抑制剤の使用量を適
正化し、安定に脱珪処理できる溶銑の脱珪処理方法を提
供することにある。また、フォーミング抑制剤の過量な
使用を回避し、一回の受銑量を許容限度まで増加させる
溶銑の脱珪処理方法を提供することを目的とするもので
ある。
SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned drawbacks of the prior art. Specifically, it is possible to accurately detect the forming and the thickness thereof that occur during the pig iron reception in the hot metal ladle. Accordingly, it is an object of the present invention to provide a method for desiliconizing hot metal that enables stable desiliconization by appropriately adjusting the amount of forming inhibitor used. Another object of the present invention is to provide a method for desiliconizing hot metal which avoids excessive use of a forming inhibitor and increases the amount of pig iron received once to an allowable limit.

【0015】[0015]

【課題を解決するための手段】[Means for Solving the Problems]

(1)請求項1の発明は、下記の工程を備えた溶銑の脱
珪方法である。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋内のスラグレベルを計測し、他
方、溶銑鍋内の溶銑重量を計測し得られた値から溶銑の
レベルを計算し、(c)前記計測した値と前記計算した
値との差が所定の値を超える場合には所定量のフォーミ
ング抑制剤を溶銑鍋に投入し、(d)溶銑の脱珪反応を
進行させる。
(1) The invention of claim 1 is a method for desiliconizing hot metal, which comprises the following steps. (A) A value obtained by measuring the slag level in the hot metal ladle while receiving the hot metal added with the desiliconizing agent in the hot metal ladle, while measuring the weight of the hot metal in the hot metal ladle The level of hot metal is calculated from (c) when the difference between the measured value and the calculated value exceeds a predetermined value, a predetermined amount of forming inhibitor is added to the hot metal ladle, and (d) The desiliconization reaction proceeds.

【0016】(2)請求項2の発明は、下記の工程を備
えた溶銑の脱珪方法である。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋のスラグレベルの測定値に基づき
スラグレベルの変化速度を計算し、他方、溶銑鍋内の溶
銑重量の測定値から溶銑レベルの変化速度を計算し、
(c)前記計測した値と前記計算した値との差が所定の
値を超える場合には所定量のフォーミング抑制剤を溶銑
鍋に投入し、(d)溶銑の脱珪反応を進行させる。
(2) A second aspect of the present invention is a method for desiliconizing hot metal, which comprises the following steps. (A) While receiving the hot metal added with the desiliconizing agent in the hot metal ladle, (b) the rate of change of the slag level is calculated based on the measured value of the slag level of the hot metal ladle, while the hot metal in the hot metal ladle is Calculate the rate of change of the hot metal level from the measured value of the hot metal weight,
(C) When the difference between the measured value and the calculated value exceeds a predetermined value, a predetermined amount of forming inhibitor is put into the hot metal ladle, and (d) the desiliconization reaction of the hot metal is allowed to proceed.

【0017】(3)請求項3の発明は、下記の工程を備
えた溶銑鍋内におけるスラグのフォーミング厚さの検知
方法である。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋内のスラグレベルを計測し、他
方、溶銑鍋内の溶銑重量を計測し得られた値から溶銑の
レベルを計算し、(c)前記計測した値と前記計算した
値との差に基づきスラグのフォーミング厚さを決定す
る。
(3) The invention of claim 3 is a method for detecting the forming thickness of slag in a hot metal ladle, which comprises the following steps. (A) A value obtained by measuring the slag level in the hot metal ladle while receiving the hot metal added with the desiliconizing agent in the hot metal ladle, while measuring the weight of the hot metal in the hot metal ladle Then, the level of hot metal is calculated, and (c) the forming thickness of the slag is determined based on the difference between the measured value and the calculated value.

【0018】(4)請求項4の発明は、下記の工程を備
えた溶銑鍋内におけるスラグのフォーミング厚さの変化
速度の検知方法である。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋のスラグレベルの測定値に基づき
スラグレベルの変化速度を計算し、他方、溶銑鍋内の溶
銑重量の測定値から溶銑レベルの変化速度を計算し、
(c)前記計算した値の差に基づきスラグのフォーミン
グ厚さの変化速度を決定する。
(4) The invention according to claim 4 is a method for detecting a changing speed of a forming thickness of slag in a hot metal ladle, which comprises the following steps. (A) While receiving the hot metal added with the desiliconizing agent in the hot metal ladle, (b) the rate of change of the slag level is calculated based on the measured value of the slag level of the hot metal ladle, while the hot metal in the hot metal ladle is Calculate the rate of change of the hot metal level from the measured value of the hot metal weight,
(C) The rate of change in the slag forming thickness is determined based on the calculated difference.

【0019】[0019]

【作用】上記の通り、本発明は、脱珪剤が添加された溶
銑を溶銑鍋中に受銑する際に、そのスラグレベルと溶銑
重量計を溶銑レベルに変換した値とをの比較を行い、ス
ラグフのォーミングの厚さ及びその変加速度を計算し、
フォーミングを検知することを特徴とする。
As described above, according to the present invention, when the hot metal added with the desiliconizing agent is received in the hot metal ladle, the slag level is compared with the value obtained by converting the hot metal weighing scale to the hot metal level. , Calculate the thickness of slug warming and its variable acceleration,
It is characterized by detecting forming.

【0020】ここで、本発明の構成並びに作用につい
て、図1及び図2に従って、具体的に説明する。図1は
本発明方法の実施態様の一例を示す図であり、図2は本
発明方法を実施した場合においてフォーミングを抑制し
ながら受銑を実施する場合の一例を経時的に示した図で
ある。以下において、スラグレベルとは溶銑鍋底からス
ラグ表面までの高さ(L1 )を、溶銑レベルとは溶銑鍋
底から溶銑湯面までの高さ(L2 )、フォーミング厚さ
とは溶銑湯面からフォーミングしたスラグ表面までの高
さである。
Here, the configuration and operation of the present invention will be specifically described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing an example of an embodiment of the method of the present invention, and FIG. 2 is a diagram showing an example of a case of performing pig iron reception while suppressing forming when the method of the present invention is carried out. . In the following, the slag level is the height from the bottom of the hot metal pot to the slag surface (L 1 ), the level of hot metal is the height from the bottom of the hot metal pot to the hot metal surface (L 2 ), and the forming thickness is the hot metal surface to forming. It is the height to the surface of the slag.

【0021】図1に示すように、高炉鋳床において脱珪
を行う際に、まず、鋳床の下に溶銑鍋5を配置し、高炉
1から主樋2を経由して溶銑鍋5へ溶銑3の受銑を開始
する。開始直後から、スラグレベル計として例えば、マ
イクロ波レベル計16によりスラグレベル値L1 を計測
し、一方、溶銑重量計15で溶銑重量を計測し、その値
から溶銑鍋の形状に基づいて溶銑レベル値L2 を計算す
る。
As shown in FIG. 1, when desiliconizing is performed in a blast furnace casting bed, first, a hot metal ladle 5 is arranged under the casting bed, and the hot metal is fed from the blast furnace 1 to the hot metal ladle 5 via the main gutter 2. Start receiving 3 pigs. Immediately after the start, as a slag level meter, for example, the microwave level meter 16 measures the slag level value L 1 , while the hot metal weight meter 15 measures the hot metal weight, and from that value, the hot metal level is determined based on the shape of the hot metal ladle. Calculate the value L 2 .

【0022】脱珪剤を添加する前は、フォーミングは発
生しないため、理論上ではL1 =L2 が成立し、前者の
レベル変動速度dL1 /dtと後者のレベル変動速度d
2/dtも理論上一致する。しかし、実際には溶銑鍋
の状態、例えば煉瓦の損耗状態等によっては、L2 ≠L
1 となることが予想される。そこで、L2a=k12
2 を定義し、L2a=L1 となるよう補正係数k1 及び
2 を決める。L2 に補正を加えて得られた値L2aを導
入し、レベル値L1 と比較し、スラグ厚さを決定する。
Before adding the desiliconizing agent, forming does not occur. Therefore, theoretically, L 1 = L 2 holds, and the former level fluctuation speed dL 1 / dt and the latter level fluctuation speed d
L 2 / dt also theoretically agrees. However, L 2 ≠ L depending on the state of the hot metal ladle, for example, the state of brick wear.
It is expected to be 1. Therefore, L 2a = k 1 L 2 +
Define the k 2, L 2a = L 1 and so as determine the correction coefficient k 1 and k 2. L 2 to introduce the value L 2a obtained by adding the correction, relative to the level value L 1, to determine the slag thickness.

【0023】ここで、k2 はゼロ点の補正であるので、
空鍋が到着した時に決定すればよい。k1 は主に煉瓦の
損耗により変化する値であるので受銑開始後例えば1〜
5分の間に決定すればよい。このような補正は後述する
マイクロコンピュウタ19により行なうことができる。
Since k 2 is the correction of the zero point,
You can decide when the empty pot arrives. Since k 1 is a value that mainly changes due to the wear of bricks, for example, 1 to 1 after the start of pig iron reception.
It may be decided within 5 minutes. Such correction can be performed by the micro computer 19 described later.

【0024】その後、傾注樋4において溶銑3に脱珪剤
11が投入されると、溶銑鍋5内でスラグのフォーミン
グが生じる。このフォーミングレベルをマイクロ波レベ
ル計16により常時監視する。マイクロ波レベル計16
は、フォーミングの発生をスラグレベルの変化により検
知するため、フォーミングが発生した場合、計測される
値L1 は大幅な増加を示す。一方、溶銑重量計15によ
り計測し換算した値L2aは、フォーミングの影響を受け
ないので、L1 とL2aとの差の変化によりフォーミング
厚さを予測することができる。
After that, when the desiliconizing agent 11 is added to the hot metal 3 in the tilting trough 4, the slag is formed in the hot metal ladle 5. The forming level is constantly monitored by the microwave level meter 16. Microwave level meter 16
Since the occurrence of forming is detected by the change in the slag level, the measured value L 1 shows a large increase when forming occurs. On the other hand, the value L 2a measured and converted by the hot metal scale 15 is not affected by forming, so that the forming thickness can be predicted by the change in the difference between L 1 and L 2a .

【0025】ここで、所定の閾値Aを設定し、下式に該
当する場合にはフォーミングが発生したとする。 ΔL=L1 −L2a>A (A:閾値) ΔLが閾値Aを超えたとき、投射ランス9からフォーミ
ング抑制剤14を投入すればよい。フォーミング抑制剤
14の投入量は、ΔLの値に応じて予め定めておくこと
も可能である。
Here, it is assumed that a predetermined threshold value A is set and that forming has occurred when the following equation is satisfied. ΔL = L 1 −L 2a > A (A: threshold value) When ΔL exceeds the threshold value A, the forming inhibitor 14 may be added from the projection lance 9. The amount of the foaming inhibitor 14 added can be determined in advance according to the value of ΔL.

【0026】また、フォーミング発生時には、スラグ湯
面が急激に上昇する場合が多いので、L1 とL2aの変化
速度の差もフォーミング検知に利用できる。ここで、別
の閾値Bを決め、下式に該当する場合にはフォーミング
が発生したとする。 ΔL’=dL1 /dt−dL2a/dt>B (B:閾
値)
In addition, when the forming occurs, the molten slag surface often rises abruptly, so the difference between the changing speeds of L 1 and L 2a can also be used for forming detection. Here, another threshold value B is determined, and when the following expression is satisfied, it is assumed that forming has occurred. ΔL '= dL 1 / dt-dL 2a / dt> B (B: threshold value)

【0027】dL2a/dtは溶銑重量から計算した溶銑
レベルの変化速度を表し、フォーミング発生により影響
を受けない。従って、ΔL’によりフォーミング速度を
検知することができる。また、閾値A、Bは、受銑量、
溶銑重量、あるいはSi値など操業条件により任意に設
定でき、A、B単独で、あるいはA、Bを組み合わせる
ことによって抑制剤投入量及び投入タイミングを制御す
ることも可能である。例えば、Aは0.3m、Bは50
mm/分のように定めることができる。
DL 2a / dt represents the rate of change of the hot metal level calculated from the weight of hot metal, and is not affected by the occurrence of forming. Therefore, the forming speed can be detected from ΔL ′. The thresholds A and B are the amount of pig iron,
It can be arbitrarily set according to operating conditions such as the weight of hot metal or Si value, and it is also possible to control the amount and timing of addition of the inhibitor by using A and B alone or by combining A and B. For example, A is 0.3 m and B is 50
It can be defined as mm / min.

【0028】また、L1 、L2aの補正ロジックに関して
は、上記方法に限らず、例えば鍋使用回数及び出銑温度
等より補正を加える、あるいは空鍋の重量から耐火物損
耗量を推定する、あるいは空鍋の耐火物損耗量の測定に
基づいて補正を行う等の方式を用いてもよい。上記にお
いて、L1 、L2aの計算、脱珪剤の投入量の制御、フォ
ーミング抑制剤の投入量の制御等はマイクロコンピュー
ターを利用した脱珪制御装置19により行なうのが望ま
しい。
Further, the correction logic of L 1 and L 2a is not limited to the above-mentioned method. For example, the correction amount is added based on the number of times the pot is used and the tapping temperature, or the amount of refractory wear is estimated from the weight of the empty pot. Alternatively, a method of making a correction based on measurement of the amount of refractory wear of the pan may be used. In the above, it is desirable that the calculation of L 1 and L 2a , the control of the amount of the desiliconizing agent, the control of the amount of the forming inhibitor, and the like are performed by the desiliconizing control device 19 using a microcomputer.

【0029】[0029]

【実施例】次に発明の実施例について図1及び図2に基
づいて説明する。まず、溶銑鍋5へ受銑開始後、マイク
ロ波レベル計16で計測したスラグレベルL1 を計測
し、また、溶銑重量計15(通常ロードセルを検出器と
した重量計である)で計測した値に補正を加えることに
より、フォーミング厚さを監視した。L1 −L2a>Aと
なった時点で抑制剤14を投入し、受銑を続けた。スラ
グレベルが一定値に達し、受銑レベルL1 が規定値以上
に達したところで受銑を終了させた。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the invention will be described with reference to FIGS. First, after starting to receive the hot metal into the hot metal ladle 5, the slag level L 1 measured by the microwave level meter 16 is measured, and the value measured by the hot metal scale 15 (which is a weight scale using a load cell as a detector) The forming thickness was monitored by applying a correction to L 1 -L 2a> charged with inhibitors 14 when it becomes the A, continued受銑. When the slag level reached a certain value and the piggyer level L 1 reached the specified value or more, the piggybacking was terminated.

【0030】図3は本発明方法によって受銑する際の受
銑重量に対するばらつきを示すグラフ、図4は従来例の
場合のばらつきを示す図である。両図から明らかなとお
り、受銑量は、従来に比べて10.1ton増加し、ば
らつきもσ=9.7ton小さくなったため、鍋使用コ
ストが低減され、さらに抑制剤14の使用量は従来の約
60%に低減できた。
FIG. 3 is a graph showing the variation with respect to the weight of the pig iron when receiving the pig iron by the method of the present invention, and FIG. 4 is a diagram showing the variation in the case of the conventional example. As is clear from both figures, the amount of pig iron received was increased by 10.1 tons and the variation was reduced by σ = 9.7 tons compared to the conventional case, so the pot usage cost was reduced and the amount of the inhibitor 14 used was smaller than that of the conventional case. It could be reduced to about 60%.

【0031】また、本実施例によれば脱珪処理後の溶銑
中珪素濃度に関し、目標濃度に対して、従来−0.01
6〜0.012wt%とばらついていたのに対して、本
実施例では−0.004〜0.002wt%と安定し、
溶銑脱燐処理、転炉等での成分調整に過大な効果を発揮
した。
Further, according to the present embodiment, the silicon concentration in the hot metal after the desiliconization treatment is conventionally set to -0.01 with respect to the target concentration.
6 to 0.012 wt%, whereas in this example, it was stable at −0.004 to 0.002 wt%,
It exerted an excessive effect on the hot metal dephosphorization treatment and the component adjustment in the converter.

【0032】本実施例では、溶銑鍋5の中の溶銑3につ
いて本発明を適用したものであるが、溶銑の容器は溶銑
鍋に限定されず、他の溶銑を入れる容器でもよい。ま
た、本実施例は、マイクロ波レベル計16を用いてスラ
グのレベル検出を行っていたが、スラグレベルが把握で
きるものであればこれに限定されない。また、本実施例
では、ロードセルを用いた溶銑重量計15で溶銑重量を
検出していたが、溶銑重量を検出できるならば他の方法
でもよい。
In the present embodiment, the present invention is applied to the hot metal 3 in the hot metal ladle 5. However, the hot metal container is not limited to the hot metal ladle, and other hot metal containers may be used. Further, in the present embodiment, the slag level is detected using the microwave level meter 16, but the present invention is not limited to this as long as the slag level can be grasped. Further, in the present embodiment, the hot metal weight meter 15 using the load cell was used to detect the hot metal weight, but other methods may be used as long as the hot metal weight can be detected.

【0033】[0033]

【発明の効果】以上、詳しく説明したとおり、本発明
は、スラグレベルと溶銑レベル、及びその変化速度と各
々比較することにより、溶銑鍋への受銑中発生するスラ
グのフォーミングを検知しながら溶銑の脱珪処理を行な
う方法であるので、スラグのフォーミングを精度良く検
知でき、また、フォーミング厚さに応じて抑制剤を投入
すること可能とする。従って、適正な抑制剤の使用によ
りSi的中率のアップを図ることがでる。さらに、フォ
ーミングの発生にかかわらず一定の受銑量を確保でき、
低コストでかつ安全に溶銑の脱珪反応を行なうことがで
きる。
As described above in detail, the present invention compares the slag level with the hot metal level and the rate of change thereof to detect the slag forming that occurs during the receipt of the hot metal in the hot metal ladle. This is a method of performing the desiliconization treatment of No. 3, so that the forming of the slag can be accurately detected, and the inhibitor can be added according to the forming thickness. Therefore, it is possible to improve the Si hit rate by using an appropriate inhibitor. Furthermore, a certain amount of pig iron can be secured regardless of the occurrence of forming,
The desiliconization reaction of hot metal can be performed safely at low cost.

【図面の簡単な説明】[Brief description of drawings]

【図1】 本発明の実施態様の一例を示す説明図であ
る。
FIG. 1 is an explanatory diagram showing an example of an embodiment of the present invention.

【図2】 本発明方法によってフォーミング発生時に受
銑を実施する場合の一例を経時的に示したグラフであ
る。
FIG. 2 is a graph showing an example of a case of performing pig iron reception when forming occurs according to the method of the present invention with time.

【図3】 本発明方法によって受銑する際の受銑重量の
ばらつきを示すグラフである。
FIG. 3 is a graph showing variations in pig iron weight when pig iron is received by the method of the present invention.

【図4】 従来の方法によって受銑する際の受銑重量の
ばらつきを示すグラフである。
FIG. 4 is a graph showing variations in pig iron weight when pig iron is received by a conventional method.

【符号の説明】 1 高炉 2 主樋 3 溶銑 4 傾注樋 5 溶銑鍋 6 脱珪剤貯蔵槽 7 混合タンク 8 脱珪剤秤量ホッパー 9 投射ランス 11 脱珪剤 12 フォーミング抑制剤の貯蔵槽 13 フォーミング抑制剤の秤量ホッパー 14 フォーミング抑制剤 15 溶銑重量計 16 マイクロ波レベル計 19 脱珪制御装置[Explanation of symbols] 1 Blast furnace 2 Main gutter 3 Hot metal 4 Inclined gutter 5 Hot metal ladle 6 Desiliconizing agent storage tank 7 Mixing tank 8 Desiliconizing agent weighing hopper 9 Projection lance 11 Desiliconizing agent 12 Forming inhibitor storage tank 13 Forming suppression Weighing agent hopper 14 Forming inhibitor 15 Hot metal scale 16 Microwave level meter 19 Desiliconization control device

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】 下記の工程を備えた溶銑の脱珪方法。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋内のスラグレベルを計測し、他
方、溶銑鍋内の溶銑重量を計測し、得られた値から溶銑
のレベルを計算し、(c)前記計測した値と前記計算し
た値との差が所定の値を超える場合には所定量のフォー
ミング抑制剤を溶銑鍋に投入し、(d)溶銑の脱珪反応
を進行させる。
1. A method of desilvering hot metal comprising the following steps. (A) While receiving the hot metal to which the desiliconizing agent was added in the hot metal ladle, (b) the slag level in the hot metal ladle was measured, while the weight of the hot metal in the hot metal ladle was measured and obtained. The level of hot metal is calculated from the value, and (c) when the difference between the measured value and the calculated value exceeds a predetermined value, a predetermined amount of forming inhibitor is added to the hot metal ladle, and (d) the hot metal. The silicon removal reaction of.
【請求項2】 下記の工程を備えた溶銑の脱珪方法。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋のスラグレベルの測定値に基づき
スラグレベルの変化速度を計算し、他方、溶銑鍋内の溶
銑重量の測定値から溶銑レベルの変化速度を計算し、
(c)前記計算した値の差が所定の値を超える場合に所
定量のフォーミング抑制剤を溶銑鍋に投入し、(d)溶
銑の脱珪反応を進行させる。
2. A method of desiliconizing hot metal comprising the following steps. (A) While receiving the hot metal added with the desiliconizing agent in the hot metal ladle, (b) the rate of change of the slag level is calculated based on the measured value of the slag level of the hot metal ladle, while the hot metal in the hot metal ladle is Calculate the rate of change of the hot metal level from the measured value of the hot metal weight,
(C) When the difference between the calculated values exceeds a predetermined value, a predetermined amount of the forming inhibitor is added to the hot metal ladle, and (d) the desiliconization reaction of the hot metal proceeds.
【請求項3】 下記の工程を備えた溶銑鍋内におけるス
ラグのフォーミング厚さの検知方法。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋内のスラグレベルを計測し、他
方、溶銑鍋内の溶銑重量を計測し、得られた値から溶銑
のレベルを計算し、(c)前記計測した値と前記計算し
た値との差に基づきスラグのフォーミング厚さを決定す
る。
3. A method for detecting the forming thickness of slag in a hot metal ladle, which comprises the following steps. (A) While receiving the hot metal to which the desiliconizing agent was added in the hot metal ladle, (b) the slag level in the hot metal ladle was measured, while the weight of the hot metal in the hot metal ladle was measured and obtained. The hot metal level is calculated from the value, and (c) the forming thickness of the slag is determined based on the difference between the measured value and the calculated value.
【請求項4】 下記の工程を備えた溶銑鍋内におけるス
ラグのフォーミング厚さの変化速度の検知方法。 (a)脱珪剤が添加された溶銑を溶銑鍋にて受銑しなが
ら、(b)前記溶銑鍋のスラグレベルの測定値に基づき
スラグレベルの変化速度を計算し、他方、溶銑鍋内の溶
銑重量の測定値から溶銑レベルの変化速度を計算し、
(c)前記計算した値の差に基づきスラグのフォーミン
グ厚さの変化速度を決定する。
4. A method for detecting the changing speed of the slag forming thickness in a hot metal ladle, which comprises the following steps. (A) While receiving the hot metal added with the desiliconizing agent in the hot metal ladle, (b) the rate of change of the slag level is calculated based on the measured value of the slag level of the hot metal ladle, while the hot metal in the hot metal ladle is Calculate the rate of change of the hot metal level from the measured value of the hot metal weight,
(C) The rate of change in the slag forming thickness is determined based on the calculated difference.
JP30840294A 1994-11-18 1994-11-18 Hot metal desiliconization method Expired - Fee Related JP3232922B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP30840294A JP3232922B2 (en) 1994-11-18 1994-11-18 Hot metal desiliconization method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP30840294A JP3232922B2 (en) 1994-11-18 1994-11-18 Hot metal desiliconization method

Publications (2)

Publication Number Publication Date
JPH08143925A true JPH08143925A (en) 1996-06-04
JP3232922B2 JP3232922B2 (en) 2001-11-26

Family

ID=17980636

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP3232922B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100426865B1 (en) * 1999-12-28 2004-04-13 주식회사 포스코 Control method of foaming for BF de-Si slag
KR100833039B1 (en) * 2001-12-26 2008-05-27 주식회사 포스코 Automation controller for charging a forming retardant

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100426865B1 (en) * 1999-12-28 2004-04-13 주식회사 포스코 Control method of foaming for BF de-Si slag
KR100833039B1 (en) * 2001-12-26 2008-05-27 주식회사 포스코 Automation controller for charging a forming retardant

Also Published As

Publication number Publication date
JP3232922B2 (en) 2001-11-26

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