【発明の詳細な説明】 （産業上の利用分野） 溶鋼の２次精錬における脱硫法に関してこの明細書に
は、溶鋼の吸い上げ、吐出反復による撹拌精錬方式の有
利な適用についての開発研究の成果に関連して以下に述
べる。DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) Regarding the desulfurization method in the secondary refining of molten steel, this specification describes the results of the development research on the advantageous application of the stirring refining method by repeating the sucking and discharging of molten steel. Relatedly, it will be described below.
（従来の技術） 従来溶鋼の取鍋精錬における脱硫は例えば特開昭５８−
１１３３１３号公報のようにＰＨ脱ガスでのCaO系フラ
ックスの添加およびCaO系フラックスの吹き込みが知ら
れている。(Prior Art) Desulfurization in the conventional ladle refining of molten steel is disclosed in, for example, JP-A-58-
As disclosed in Japanese Patent No. 113313, addition of CaO-based flux and injection of CaO-based flux in PH degassing are known.
しかしＰＨ脱ガスでのフラックス添加は耐火物の損耗が
大きく、処理コストが高価である。また溶鋼中に不活性
ガスを吹き込んで撹拌処理するフラッシング処理材はＰ
Ｈ脱ガス装置が処理を行っていない場合に使用すること
に限られるために迅速な対応ができない。However, the addition of the flux in PH degassing causes a large amount of wear of the refractory and the treatment cost is high. In addition, the flushing treatment material in which an inert gas is blown into molten steel to perform stirring treatment is P
Since it is limited to use when the H 2 degassing device is not processing, it is not possible to respond promptly.
一方、CaO系フラックスの吹き込みは溶鋼の温度降下が
著しい欠点を残している。On the other hand, CaO-based flux blowing has a drawback that the temperature drop of molten steel is remarkable.
（発明が解決しようとする問題点） 取鍋精錬において、溶鋼の温度の均一化および脱酸と同
時に、耐火物溶損や、温度降下を伴うことなく、CaO系
の安価な脱硫剤にて低コストで脱硫を行う、有利な方法
を与えることがこの発明の目的である。(Problems to be solved by the invention) In ladle refining, the temperature of molten steel is homogenized and deoxidized, and at the same time, there is no melting of refractories and no temperature drop, and a low-cost CaO-based desulfurizing agent is used. It is an object of the present invention to provide an advantageous method of performing desulfurization at cost.
（問題点を解決するための手段） この発明は、精錬容器内に収容した溶鋼中に、これに面
して開口する筒形耐火物の下端を浸漬し、この浸漬端と
反対側の筒形耐火物の内部を減圧加圧に交互に反転する
間に、当該筒形耐火物中に一旦吸い上げた溶鋼を急速に
吐出する操作の反復で溶融金属浴に撹拌を強いる取鍋精
錬に際して、筒形耐火物内にCaO系フラックスを下記式
に示す添加速度ｆで添加し脱酸を行いつつ脱硫すること
を特徴とする溶鋼の吸い上げ、吐出反復による撹拌精錬
方式脱硫法 記 ここに ｆ：脱硫剤添加速度(kg/t・min) Ａ：筒形耐火物内断面積(cm2) ｈ：筒形耐火物内溶鋼ストローク(m) ρ：脱硫剤比重（−） Ｔ：加減圧周期(sec) Ｗ：溶鋼重量(ton) である。(Means for Solving the Problems) The present invention is to immerse a lower end of a tubular refractory material, which is opened facing the molten steel, in a molten steel housed in a refining vessel, and to form a cylindrical shape on the side opposite to the immersed end. While alternately reversing the inside of the refractory to depressurization and pressurization, the tubular shape is used for ladle refining in which the molten metal bath is agitated by repeating the operation of rapidly discharging the molten steel once sucked into the tubular refractory. A CaO-based flux is added to the refractory at an addition rate f shown in the following formula to perform desulfurization while performing deoxidation, and the molten steel is sucked and discharged repeatedly. Where f: Desulfurizing agent addition rate (kg / t ・ min) A: Cross-sectional area of tubular refractory (cm2 ) h: Stroke of molten steel in tubular refractory (m) ρ: Desulfurizing agent specific gravity (-) T: Pressurization / depressurization cycle (sec) W: Molten steel weight (ton).
（作 用） この発明の作用は、 1. 溶鋼の撹拌力を増加し、脱硫剤を均一に溶鋼内に分
散する。(Operation) The effects of the present invention are: 1. Increase the stirring force of the molten steel and uniformly disperse the desulfurizing agent in the molten steel.
2. 脱硫剤の溶鋼内滞留時間を長くする。2. Prolong the residence time of desulfurizing agent in molten steel.
3. 溶鋼表面に存在するスラグの撹拌を防止し、スラグ
の酸素ポテンシャル低下等の改質を行うことなく脱硫が
促進される。3. Prevents agitation of slag existing on the surface of molten steel, and promotes desulfurization without modification such as reduction of oxygen potential of slag.
のであり、ここに脱硫剤としてはCaO系、とくにCaO-CaF
2-Al系フラックスを使用して脱硫剤近傍を脱酸すると脱
硫反応を促進させ得る。Therefore, here, as a desulfurizing agent, CaO type, especially CaO-CaF
Desulfurization in the vicinity of the desulfurizing agent using2- Al flux can accelerate the desulfurization reaction.
このようにして短時間の周期で筒形耐火物内の加圧をく
り返し、とくに溶鋼の吐出速度を増大するために急速な
加圧を行うことが必要である。第１図に溶鋼の吸い上げ
吐出反復による撹拌精錬方式に従う精錬設備を模式にて
示した。In this way, it is necessary to repeat the pressurization in the tubular refractory in a short period of time, and in particular, to rapidly press the molten steel in order to increase the discharge rate. Fig. 1 schematically shows the refining equipment according to the stirring refining method by repeating suction and discharge of molten steel.
図中１は取鍋、２は溶鋼、３はスラグである。In the figure, 1 is a ladle, 2 is molten steel, and 3 is slag.
筒形耐火物４の下端を溶鋼２中に浸漬し、排気系配管９
から筒形耐火物４内を減圧することにより、溶鋼２を吸
い上げた後、加圧系配管11によって筒形耐火物４内を急
速に加圧し、取鍋１内に溶鋼２を吐出す。The lower end of the tubular refractory 4 is immersed in the molten steel 2 and the exhaust system piping 9
After the molten steel 2 is sucked up by decompressing the inside of the cylindrical refractory 4, the inside of the cylindrical refractory 4 is rapidly pressurized by the pressurizing system pipe 11, and the molten steel 2 is discharged into the ladle 1.
以上の操作を周期的に繰り返すことによって取鍋内の溶
鋼の撹拌を行う。The molten steel in the ladle is agitated by periodically repeating the above operation.
上記処理中に筒形耐火物４の上部に設置したホッパー７
から脱硫剤６を添加する。添加した脱硫剤６は、溶鋼吐
出し時に溶鋼２と混合させて、取鍋１内に下向きに吐出
させる。水モデル実験の結果、取鍋２底部の撹拌力が大
きく、溶鋼表面のスラグ３近傍の撹拌は弱いことが確か
められている。A hopper 7 installed above the tubular refractory 4 during the above treatment
Desulfurization agent 6 is added. The added desulfurizing agent 6 is mixed with the molten steel 2 at the time of discharging the molten steel and discharged downward into the ladle 1. As a result of the water model experiment, it has been confirmed that the stirring force at the bottom of the ladle 2 is large and that the stirring near the slag 3 on the molten steel surface is weak.
従って脱硫剤６は溶鋼２とともに取鍋１の底部付近まで
達した後、脱硫反応を伴いつつ浮上する。脱硫剤６の溶
鋼２内滞留時間が長いため、反応効率が高く、スラグ３
を撹拌しないために復Ｐ、復Ｓがない。Therefore, the desulfurization agent 6 reaches the vicinity of the bottom of the ladle 1 together with the molten steel 2, and then floats up with a desulfurization reaction. Since the residence time of the desulfurization agent 6 in the molten steel 2 is long, the reaction efficiency is high and the slag 3
Since there is no stirring, there is no return P or return S.
脱硫反応は溶鋼２中で(1)式に従って進行する。The desulfurization reaction proceeds in molten steel 2 according to equation (1).
CaO＋Ｓ ＝CaS＋Ｏ (1) 安価なCaO系フラックスを脱硫剤６として用い、脱硫を
促進するためには、脱硫剤近傍の酸素ポテンシャルを低
下させるためＡｌを加えたCaO-CaF2-Al系フラックスを
使用することが好ましいことがわかった。CaO +S = CaS +O (1) In order to promote desulfurization by using an inexpensive CaO-based flux as the desulfurization agent 6, CaO-CaF2 -Al-based flux with Al added to reduce the oxygen potential near the desulfurization agent. It has been found preferable to use
添加速度は、筒形耐火物４内の脱硫剤６による閉塞を防
止するためには、筒形耐火物４内溶鋼体積の10％以下に
することが必要であることが見出されている。It has been found that the addition rate needs to be 10% or less of the molten steel volume in the tubular refractory 4 in order to prevent clogging by the desulfurizing agent 6 in the tubular refractory 4.
すなわち、添加速度は次式と範囲でなければならない。That is, the addition rate must be within the following formula and range.
ｆ：添加速度(kg/t・min) Ａ：筒形耐火物内断面積(cm2) ｈ：筒形耐火物内溶鋼ストローク(m) ρ：脱硫剤比重（−） Ｔ：加減圧周期(sec) Ｗ：溶鋼重量(ton) また脱硫効率は、添加速度が小さい程のぞましいが脱硫
剤量が0.3kg/t未満の場合の脱硫量は低く0.3kg/t以上の
脱硫剤が必要であり、かつ標準的処理時間が30分以内と
して第２図より添加速度0.01kg/t・min以上が適切である
ことを見出した。 f: Addition rate (kg / t · min) A: Cross-sectional area of tubular refractory (cm2 ) h: Stroke of molten steel in tubular refractory (m) ρ: Specific gravity of desulfurizing agent (-) T: Pressure cycle sec) W: Weight of molten steel (ton) Also, desulfurization efficiency is desirable as the addition rate is small, but when the amount of desulfurization agent is less than 0.3 kg / t, the desulfurization amount is low and desulfurization agent of 0.3 kg / t or more is required. Moreover, it was found from Fig. 2 that a standard treatment time of 30 minutes or less is suitable for an addition rate of 0.01 kg / t · min or more.
（実施例） 転炉吹錬後第１図に示した装置で取鍋内の溶鋼250tにつ
いて脱硫剤添加実験を下記条件で行った。(Example) After the converter was blown, a desulfurizing agent addition experiment was carried out on 250 t of molten steel in a ladle using the apparatus shown in Fig. 1 under the following conditions.
脱硫剤には18Ca-20Al-38CaO-21Al2O3、粒度8mm以下、添
加量4.2kg/t（溶鋼）を用いた。As the desulfurizing agent, 18Ca-20Al-38CaO-21Al2 O3 , a grain size of 8 mm or less, and an addition amount of 4.2 kg / t (molten steel) were used.
溶鋼吸い上げ、吐出を１サイクル毎７秒で、加圧＋200m
mHg〜減圧−550mmHg（圧力差750mmHg）で反復、処理時
間15分とした。Suction and discharge of molten steel in 7 seconds per cycle, pressurization + 200m
It was repeated from mHg to reduced pressure-550 mmHg (pressure difference 750 mmHg), and the treatment time was 15 minutes.
筒形耐火物内断面積Ａ：耐火物内径45cmより溶鋼ストロークｈ：加減圧圧力差750mmHgから脱硫剤比重ρ：約２ 加減圧周期Ｔ：７sec 溶鋼重量 Ｗ：250 ton とおくと、となり、ｆ：添加速度はこの処理15分中における脱硫剤
添加時間が約７分間であり、添加量は4.2kg/tで添加す
ると、従って0.01＜ｆ＝0.6＜1.6 となる。Tubular refractory inner cross-sectional area A: Refractory inner diameter from 45 cm Molten steel stroke h: From pressure difference of 750 mmHg Desulfurization agent specific gravity ρ: Approx. 2 Pressurization / depressurization cycle T: 7 seconds Molten steel weight W: 250 ton F: The addition rate is such that the desulfurization agent addition time is about 7 minutes in 15 minutes of this treatment, and the addition amount is 4.2 kg / t, Therefore, 0.01 <f = 0.6 <1.6.
上記実験の結果は次表のとおりである。The results of the above experiment are shown in the following table.
（発明の効果） 転炉出鋼時の分析におけるＳ外れ材についてこの発明の
方法によって脱硫処理すれば、ＰＨ脱ガス装置のごとき
大がかりな設備を使用することなく、安価、確実に有効
な脱硫を有利に実現することができる。 (Effects of the Invention) By performing desulfurization treatment on the S outgas in the analysis at the time of tapping of the converter, the desulfurization can be performed inexpensively and reliably without using large equipment such as a PH degasser. It can be realized advantageously.
第１図は撹拌精錬装置の模式図、 第２図は脱硫剤添加速度と処理時間との関係図表であ
る。FIG. 1 is a schematic diagram of an agitating and refining device, and FIG. 2 is a relational chart of a desulfurizing agent addition rate and a treatment time.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8452685AJPH06927B2 (en) | 1985-04-22 | 1985-04-22 | Agitating and refining method desulfurization method by repeatedly sucking and discharging molten steel |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8452685AJPH06927B2 (en) | 1985-04-22 | 1985-04-22 | Agitating and refining method desulfurization method by repeatedly sucking and discharging molten steel |
| Publication Number | Publication Date |
|---|---|
| JPS61246311A JPS61246311A (en) | 1986-11-01 |
| JPH06927B2true JPH06927B2 (en) | 1994-01-05 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8452685AExpired - LifetimeJPH06927B2 (en) | 1985-04-22 | 1985-04-22 | Agitating and refining method desulfurization method by repeatedly sucking and discharging molten steel |
| Country | Link |
|---|---|
| JP (1) | JPH06927B2 (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9008369B2 (en) | 2004-04-15 | 2015-04-14 | Magna Electronics Inc. | Vision system for vehicle |
| CN105400929A (en)* | 2015-11-17 | 2016-03-16 | 北京首钢自动化信息技术有限公司 | Method for controlling KR final sulphur content |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9008369B2 (en) | 2004-04-15 | 2015-04-14 | Magna Electronics Inc. | Vision system for vehicle |
| CN105400929A (en)* | 2015-11-17 | 2016-03-16 | 北京首钢自动化信息技术有限公司 | Method for controlling KR final sulphur content |
| Publication number | Publication date |
|---|---|
| JPS61246311A (en) | 1986-11-01 |
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