JPS6151603B2 - - Google Patents
Info
- Publication number
- JPS6151603B2 JPS6151603B2 JP55165334A JP16533480A JPS6151603B2 JP S6151603 B2 JPS6151603 B2 JP S6151603B2 JP 55165334 A JP55165334 A JP 55165334A JP 16533480 A JP16533480 A JP 16533480A JP S6151603 B2 JPS6151603 B2 JP S6151603B2
- Authority
- JP
- Japan
- Prior art keywords
- blowing
- lance
- furnace
- tuyere
- jet
- 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
Links
- 238000007664 blowing Methods 0.000 claims description 40
- 238000000034 method Methods 0.000 claims description 20
- 229910000831 Steel Inorganic materials 0.000 claims description 18
- 239000010959 steel Substances 0.000 claims description 18
- 238000003756 stirring Methods 0.000 claims description 8
- 239000002893 slag Substances 0.000 description 14
- 239000007789 gas Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000013019 agitation Methods 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/30—Regulating or controlling the blowing
- C21C5/35—Blowing from above and through the bath
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
Description
この発明は上吹き酸素ランスから酸素を吹込む
と共に、炉底より撹拌ガスを吹込む上下吹錬法に
関する。
近年転炉が大型化するに伴い上吹きランスから
吹込まれるO2ジエツトだけでは溶鋼の撹拌が十
分に行われず、そのため反応が遅れるという問題
が生じてきている。この点を解決するために炉底
に羽口を設けて、この羽口より撹拌ガスを吹込
み、これにより溶鋼の撹拌及び反応の促進を図つ
た上下吹錬法が行われるようになつてきている。
この上下吹錬法において、O2の上吹きは従前
の上吹き吹錬法によるものをそのまま行つている
のが現状であり、上下吹錬法における独自のO2
上吹き法はまだ開発、提案されていない。
すなわち、上吹き吹錬では鋼浴の撹拌を上吹き
O2ジエツトだけで行つているため、O2ジエツト
の鋼浴への侵入深さが鋼浴の深さの60〜90％必要
とされ、O2ジエツトの鋼浴面の垂線のなす角度
（以下O2ジジエツト角度とする）は通常小さく設
定されており、上下吹錬法においてもこれがその
まま踏襲されている。
現在上下吹錬において用いられている該O2ジ
エツト角度を各規模の転炉について下表に示す。
なお、O2ジエツト角度は以下ランスノズルのス
ロートの中心線と鋼溶面の垂線のなす角度（以下
スロート角度とする）として表わす。
This invention relates to a top-bottom blowing method in which oxygen is blown from a top-blowing oxygen lance and stirring gas is blown from the bottom of the furnace. In recent years, as converters have become larger, the problem has arisen that the O 2 jet blown from the top blowing lance alone is not sufficient to stir the molten steel, resulting in delayed reactions. In order to solve this problem, the top-bottom blowing method, in which a tuyere is installed at the bottom of the furnace and stirring gas is blown into the tuyere to promote stirring and reaction of the molten steel, has come to be used. There is. In this top-bottom blowing method, the O 2 top-blowing is currently carried out in the same manner as the previous top-blowing method;
The top blowing method has not yet been developed or proposed. In other words, in top blowing, the stirring of the steel bath is
Since this is done using only an O 2 jet, the penetration depth of the O 2 jet into the steel bath is required to be 60 to 90% of the depth of the steel bath, and the angle formed by the perpendicular to the steel bath surface of the O 2 jet (hereinafter referred to as The O 2 jet angle) is normally set small, and this is followed in the top-bottom blowing method as well. The O 2 jet angles currently used in top and bottom blowing are shown in the table below for converters of various sizes.
The O 2 jet angle is hereinafter expressed as the angle between the center line of the throat of the lance nozzle and the perpendicular to the steel melting surface (hereinafter referred to as the throat angle).
【表】
しかし、本発明者らは上下吹錬法の経験を重ね
るうちに、このような従前の上吹き吹錬における
ランスノズルのスロート角度をそのまま適用する
と、主として生石灰等の副原料の初期の滓化が遅
れ、高炭素材の脱リングが悪化する傾向にあると
いう問題に直面した。これを第１図のグラフに示
す。各プロツトは次の通りである。
△……上下吹錬法の場合のスラグ塩基度
▲……上吹き吹錬法の場合のスラグ塩基度
〇……上下吹錬法の場合の鋼中〔Ｐ〕％
●……上吹き吹錬法の場合の鋼中〔Ｐ〕％
このグラフからわかるように吹錬初期において
は、スラグ塩基度及び溶鋼中〔Ｐ〕％ともに上下
吹錬法が劣つている。
この発明は上記したような従来の上下吹錬法の
欠点を改善するために種々の試験、研究を重ねた
結果なされたもので、ランスノズルのスロート角
度を特定な値にすることにより滓化の促進及び脱
リンの促進を図ろうとするものである。
本発明者らは、実炉及び水モデル等による実験
の結果、次のような知見を得た。まず上下吹錬に
おいて滓化の遅れや脱リンの悪化が生ずるのは、
第２図に示すように炉底に設けられた羽口３から
吹込まれる撹拌ガスにより、溶鋼４に矢印のよう
な流れが形成され、スラグ５は炉体１の炉壁周囲
に滞留し、スラグ５がO2ジエツト６による火点
外にあるためである。次に上下吹錬においては浴
鋼の撹拌は炉底羽口よりの底吹きガスにより十分
に達成されており、上吹きランスＡは溶銑中への
酸素供給及びスラグの生成の役割りを分担してい
るだけである。
本発明者らは、このような知見に基づき本発明
を完成したもので、ランスノズルのスロート角度
を従来の上吹き吹錬の場合よりも拡げ、O2ジエ
ツトがスラグに効果的に当たるように前記スロー
トの最高角度を上吹きランス位置、鋼浴湯面の位
置、炉底羽口位置及び炉内径との関係において求
めたものである。
即ち、本発明による上下吹錬において、上吹き
ランスノズルのスロート角度θは次の条件を満た
すべく設定される。
ｄ＜（Ｈ＋ｌ）・tanθ＜Ｄ
ここで、ｄ、Ｈ、ｌ及びＤは第３図に示すよう
に定義される。即ち、
Ｈ：ランスノズル２の下端から溶鋼４の湯面まで
の距離。
ｌ：ランスノズル２の下端からランスノズルのス
ロート２０の中心線２０ａとランスノズルの中
心線２ａとの交点までの距離。
Ｄ：炉体中心１ａから炉体の内壁１０までの距
離。
ｄ：炉体中心１ａから羽口３までの距離。
ここで、ｄ＜（Ｈ＋ｌ）・tanθとしたのは、（Ｈ
＋ｌ）・tanθｄであると、O2ジエツト６の火
点が羽口３位置より炉中心側となり、スラグ５が
炉壁周囲に滞留して撹拌が促進されないためであ
る。この条件を満たす具体的な数値としては一般
的にθ12°好ましくはθ15゜である。
次に（Ｈ＋ｌ）・tanθ＜Ｄとしたのは、（Ｈ＋
ｌ）・tanθＤであると、O2ジエツト６が炉体
の内壁１０に当たり、炉体の耐火物のO2ジエツ
トによる溶損が助長されるためである。
次に実施例を示す。
実施例
180TON転炉を用いて本発明による上下吹錬と
従来法による上下吹錬とを行つた。副原料等の使
用量は従来法及び本発明法全く同様とした。各寸
法は次の通りであつた。
Ｈ：2000mm
ｌ：550mm
Ｄ：2200mm
ｄ：500mm
これを本発明の条件式に代入すると、
500＜2550・tanθ＜2200
が得られる。
本発明方法においてはθ＝25゜、従来法におい
てはθ＝６゜とした。
この結果を下掲第２表に示す。[Table] However, as the inventors have accumulated experience with the top-bottom blowing method, we have found that if the throat angle of the lance nozzle used in the conventional top-blowing method is applied as is, the initial The problem faced was that slag formation was delayed and deringing of high carbon materials tended to worsen. This is shown in the graph of FIG. Each plot is as follows. △...Slag basicity in the case of the top-bottom blowing method▲...Slag basicity in the case of the top-blowing method〇......[P]% in steel in the case of the top-bottom blowing method ●...Slag basicity in the case of the top-bottom blowing method As can be seen from this graph, in the early stage of blowing, the top-bottom blowing method is inferior in both slag basicity and [P]% in molten steel. This invention was made as a result of various tests and studies to improve the shortcomings of the conventional top-bottom blowing method as described above, and it is possible to prevent slag formation by setting the throat angle of the lance nozzle to a specific value. The aim is to promote dephosphorization and dephosphorization. The present inventors obtained the following knowledge as a result of experiments using an actual reactor, a water model, etc. First of all, the reason for the delay in slag formation and worsening of dephosphorization in upper and lower blowing is that
As shown in FIG. 2, the stirring gas blown in from the tuyere 3 provided at the bottom of the furnace forms a flow in the molten steel 4 as shown by the arrow, and the slag 5 stays around the furnace wall of the furnace body 1. This is because the slag 5 is outside the ignition point caused by the O 2 jet 6. Next, in top-bottom blowing, agitation of the bath steel is sufficiently achieved by bottom-blowing gas from the bottom tuyere, and top-blowing lance A takes on the role of supplying oxygen into the hot metal and generating slag. It's just that. The present inventors completed the present invention based on such knowledge, and the throat angle of the lance nozzle was made wider than in the case of conventional top-blowing, and the O 2 jet was made to hit the slag effectively. The maximum throat angle was determined in relation to the top blow lance position, the steel bath surface position, the furnace bottom tuyere position, and the furnace inner diameter. That is, in the top-bottom blowing according to the present invention, the throat angle θ of the top-blowing lance nozzle is set to satisfy the following condition. d<(H+l)・tanθ<D Here, d, H, l, and D are defined as shown in FIG. That is, H: distance from the lower end of the lance nozzle 2 to the surface of the molten steel 4. l: Distance from the lower end of the lance nozzle 2 to the intersection of the center line 20a of the throat 20 of the lance nozzle and the center line 2a of the lance nozzle. D: Distance from the center 1a of the furnace body to the inner wall 10 of the furnace body. d: Distance from the center 1a of the furnace body to the tuyere 3. Here, d<(H+l)・tanθ is set as (H
+l)·tanθd, the fire point of the O 2 jet 6 will be closer to the furnace center than the tuyere 3 position, and the slag 5 will stay around the furnace wall and stirring will not be promoted. A specific value that satisfies this condition is generally θ12°, preferably θ15°. Next, we set (H+l)・tanθ<D because (H+
This is because, if l)·tan θD, the O 2 jet 6 hits the inner wall 10 of the furnace body, and the melting of the refractory of the furnace body by the O 2 jet is promoted. Next, examples will be shown. Example A 180 TON converter was used to perform top and bottom blowing according to the present invention and top and bottom blowing according to the conventional method. The amounts of auxiliary raw materials used were exactly the same as in the conventional method and the present invention method. Each dimension was as follows. H: 2000mm l: 550mm D: 2200mm d: 500mm Substituting this into the conditional expression of the present invention yields 500<2550·tanθ<2200. In the method of the present invention, θ=25°, and in the conventional method, θ=6°. The results are shown in Table 2 below.
【表】
上掲表からわかるように、本発明方法の場合、
0.26％の終点〔Ｃ〕であつても〔Ｐ〕レベルは従
来の0.045％に比較し、0.022％まで低下し良好な
結果を示している。[Table] As can be seen from the above table, in the case of the method of the present invention,
Even at the end point [C] of 0.26%, the [P] level was reduced to 0.022% compared to the conventional 0.045%, showing good results.
第１図は吹錬時間とスラグ塩基度及び溶鋼中
〔Ｐ〕との関係を示すグラフ、第２図は従来の上
下吹錬法の説明図、第３図は本発明による上下吹
錬法の説明図である。
図中、Ａは上吹きランス、１は炉体、２は上吹
きランスノズル、３は炉底羽口、４は溶鋼、５は
スラグ、６はO2ジエツト、１０は内壁、２０は
上吹きランスノズルのスロートを各示す。
Fig. 1 is a graph showing the relationship between blowing time, slag basicity, and molten steel [P], Fig. 2 is an explanatory diagram of the conventional top-bottom blowing method, and Fig. 3 is a graph showing the top-bottom blowing method according to the present invention. It is an explanatory diagram. In the figure, A is the top blowing lance, 1 is the furnace body, 2 is the top blowing lance nozzle, 3 is the bottom tuyere, 4 is the molten steel, 5 is the slag, 6 is the O 2 jet, 10 is the inner wall, and 20 is the top blowing The throat of the lance nozzle is shown.
Claims (1)
に吹込むと共に、炉底に羽口を設けてこの羽口よ
り撹拌ガスを吹込む上下吹錬法において、前記上
吹きランスノズルのスロートの中心線と鋼浴面の
垂線のなす角度θが下記条件を満たすように吹錬
を行うことを特徴とする上下吹錬法。 ｄ＜（Ｈ＋ｌ）・tanθ＜Ｄ 但し、 Ｈ：ランスノズル下端から鋼浴湯面までの距離。 ｌ：ランスノズルのスロートの中心線の延長とラ
ンスの中心線の交点からランスノズル下端まで
の距離。 Ｄ：炉体中心から炉内壁までの距離。 ｄ：炉体中心から炉底羽口までの距離。[Scope of Claims] 1 In the top-bottom blowing method in which O 2 jet is blown into the steel bath from a top-blowing lance nozzle, and a tuyere is provided at the bottom of the furnace and stirring gas is blown from the tuyere, the above-mentioned top-blowing lance A top-down blowing method characterized by performing blowing so that the angle θ between the center line of the nozzle throat and the perpendicular to the steel bath surface satisfies the following conditions. d<(H+l)・tanθ<D However, H: Distance from the lower end of the lance nozzle to the steel bath surface. l: Distance from the intersection of the extension of the center line of the throat of the lance nozzle and the center line of the lance to the lower end of the lance nozzle. D: Distance from the center of the furnace body to the inner wall of the furnace. d: Distance from the center of the furnace body to the bottom tuyere.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16533480A JPS5789415A (en) | 1980-11-26 | 1980-11-26 | Top and bottom blowing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16533480A JPS5789415A (en) | 1980-11-26 | 1980-11-26 | Top and bottom blowing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5789415A JPS5789415A (en) | 1982-06-03 |
| JPS6151603B2 true JPS6151603B2 (en) | 1986-11-10 |
Family
ID=15810352
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16533480A Granted JPS5789415A (en) | 1980-11-26 | 1980-11-26 | Top and bottom blowing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5789415A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6334638U (en) * | 1986-08-21 | 1988-03-05 | ||
| JPH0439313U (en) * | 1990-07-27 | 1992-04-03 | ||
| JPH0514889Y2 (en) * | 1986-05-15 | 1993-04-20 |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49113714A (en) * | 1973-02-12 | 1974-10-30 |
-
1980
- 1980-11-26 JP JP16533480A patent/JPS5789415A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49113714A (en) * | 1973-02-12 | 1974-10-30 |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0514889Y2 (en) * | 1986-05-15 | 1993-04-20 | ||
| JPS6334638U (en) * | 1986-08-21 | 1988-03-05 | ||
| JPH0439313U (en) * | 1990-07-27 | 1992-04-03 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5789415A (en) | 1982-06-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3701519A (en) | Apparatus for the continuous refining of metals | |
| JPS6151603B2 (en) | ||
| US4462825A (en) | Method for increasing the scrap melting capability of metal refining processes | |
| EP0060305B1 (en) | Method for smelting using top-and bottom-blown converter | |
| JP4686880B2 (en) | Hot phosphorus dephosphorization method | |
| JPH0416526B2 (en) | ||
| JPS5743919A (en) | Method for blow refining in top and/or bottom-blown converter | |
| JP2013209746A (en) | Method for refining molten iron in converter type refining furnace | |
| JP2890428B2 (en) | Smelting reduction method | |
| JPH0543924A (en) | Secondary combustion blow-refining method | |
| JPS6056009A (en) | Steel making method | |
| US4292073A (en) | Steel making process | |
| JPH1192815A (en) | Converter blowing for restraining generation of dust | |
| JPH1192814A (en) | Converter blowing for restraining generation of dust | |
| JPS6152212B2 (en) | ||
| JPH0598331A (en) | Blowing operation method for oxygen converter | |
| JPH065406Y2 (en) | Converter blowing lance | |
| JPS6154081B2 (en) | ||
| JP2627103B2 (en) | Decarburization refining method of chromium-containing molten steel | |
| JPH0469204B2 (en) | ||
| JPS6152210B2 (en) | ||
| JPH01172504A (en) | Smelting reduction method for cr raw ore | |
| JPH01129923A (en) | Bottom blowing nozzle | |
| JPH0535842U (en) | Converter type metallurgical reactor | |
| JPH01172547A (en) | Smelting reduction furnace for cr material |