JPS59145718A - Blowing method of gas in nozzle for refining molten metal - Google Patents
Blowing method of gas in nozzle for refining molten metalInfo
- Publication number
- JPS59145718A JPS59145718A JP58019622A JP1962283A JPS59145718A JP S59145718 A JPS59145718 A JP S59145718A JP 58019622 A JP58019622 A JP 58019622A JP 1962283 A JP1962283 A JP 1962283A JP S59145718 A JPS59145718 A JP S59145718A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- blowing
- blown
- tuyere
- stirring
- 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.)
- Pending
Links
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
-
- 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
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/143—Reduction of greenhouse gas [GHG] emissions of methane [CH4]
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、溶融金属の上下吹き吹錬(複合吹錬法)法に
おいて、底吹き羽口の耐用寿命を向上させ転炉−炉代使
用できるようにするとともに併せてその左き使用するガ
スをコスト的に有利ならしめることな目的とするガスの
吹込み方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention improves the service life of the bottom blowing tuyere in the top and bottom blowing method (combined blowing method) of molten metal, and makes it possible to use the converter instead of the furnace. The present invention relates to a method for blowing gas, the purpose of which is to make the gas used cost-effective.
上下吹き吹錬法は、その概略を第1図に示す如く転炉(
1)内の溶鉄(5)及びスラグ(6)の上部よりランス
(7) Kて酸素を上吹きするとともに、転炉(1)の
底部に設けた羽口(4)より攪拌ガスを吹込んで溶鉄及
びスラグの攪拌、混合を強化し、結果としてスラグ中に
残存する鉄酸化物の還元を促進し、鉄歩留りの向上と吹
止めMnの上昇、脱燐を図る精錬方法である。なお、図
中の(2)1ま鉄皮であり、(3)は耐火物である。こ
こで転炉(1)の底部に設けられる別報の一例を第2図
に示す。(8)は鉄板で構成されたガス箱で詑り、(9
)は非多孔質耐火物(例えばMgO質。The top-bottom blowing method uses a converter (as shown in Figure 1).
Oxygen is blown upward from the top of the molten iron (5) and slag (6) in the converter (1) using a lance (7), and stirring gas is blown through the tuyere (4) provided at the bottom of the converter (1). This is a refining method that strengthens the stirring and mixing of molten iron and slag, thereby promoting the reduction of iron oxides remaining in the slag, improving the iron yield, increasing the blowstop Mn, and dephosphorizing. Note that (2) 1 in the figure is an iron shell, and (3) is a refractory. An example of the separate notice provided at the bottom of the converter (1) is shown in FIG. 2. (8) is plowed with a gas box made of iron plate, (9)
) is a non-porous refractory (for example, MgO).
MgO−” CaO質、Mg0−C質耐火物)に多数の
細孔(10を設け、所定の流量のガスを炉内に吹込める
ようにしである。なお、図中(3′)は永久張り耐火物
であり、(6つは内張り耐火物である。A large number of pores (10) are provided in the MgO-" CaO-based refractory, Mg0-C-based refractory) so that a predetermined flow rate of gas can be injected into the furnace. Note that (3') in the figure indicates the permanent tension (6 are lined refractories.
併して、従来の複合吹錬法においては、この羽口(4)
より溶鉄攪拌のため吹込むガスの種類としてCO2,A
r、 N2.酸素、空気等かそれぞれ単独のかたちで用
いられていた。しかし、Arのような高価なガスを単独
で用いることは羽口寿命上好ましくて・もコスト的に不
利であり、主として用いられていたのはCO2であり9
.一部には酸素等も用いられていた。In addition, in the conventional composite blowing method, this tuyere (4)
CO2, A as the type of gas injected for stirring molten iron.
r, N2. Oxygen, air, etc. were each used in their own form. However, although using an expensive gas such as Ar alone is preferable in terms of tuyere life, it is disadvantageous in terms of cost, and CO2 has been mainly used.
.. Oxygen was also used in some cases.
ところが、このような酸化性ガスを底吹きガスとして用
いた場合は、羽口■の損耗がはげしく、−炉代(転炉内
張〜り耐火物の耐用寿命と一致する寿命を持つこと)使
用−することができなかった。However, when such an oxidizing gas is used as a bottom blowing gas, the wear and tear of the tuyeres is severe, and the life of the refractory (which must have a lifespan equal to that of the refractory lining the converter) is extremely high. -I couldn't do it.
そのため、上記の精錬法の優位性も損われるという問題
があり、これの改善か要望されていた。Therefore, there is a problem that the superiority of the above-mentioned refining method is lost, and improvements to this problem have been desired.
そこで、発明者らは、羽口の耐用寿命の向上を図るため
損耗速度と損耗の機構について検討した結果、下吹きガ
スとじてCO2の如き酸化性ガスを用いた場合と、Ar
、 N2の如き非酸化性ガス又はCOの如き還元性ガス
を用いた場合とでは損耗の機構及び速度が太き(異なる
ことを知った。即ち、CO2の如き酸化性ガスを吹込ん
だ羽口においては、羽口の稼動面近傍にFeOの高いス
ラグ層(スラグ成分中の重量%がFeO: 50%、M
go:35%、 MnO:15%)が1.0〜1.5霧
の厚さ生成し、この生成スラグが羽口耐火物の主成分で
あるMgO、力−ホ゛ンを侵食して、損耗が進行する。Therefore, in order to improve the service life of the tuyeres, the inventors studied the wear rate and wear mechanism, and found that there are cases in which an oxidizing gas such as CO2 is used as the bottom blowing gas, and cases in which Ar
, I learned that the mechanism and rate of wear are different when using a non-oxidizing gas such as N2 or a reducing gas such as CO. In this case, a slag layer with high FeO content (wt% of the slag component is FeO: 50%, M
MgO: 35%, MnO: 15%) is generated to a thickness of 1.0 to 1.5 mist, and this generated slag erodes MgO and carbon, which are the main components of the tuyere refractories, resulting in wear and tear. proceed.
一方、Ar、 N2の如き非酸化性ガス又はCOの如
き還元性ガスを吹込んだ羽口においては、上記の高Fe
Oスラグ圧よる損耗は見られず、転炉スラグによる損耗
を受けるのみである。その結果高FeOスラグと転炉ス
ラグの違いによる損耗速度差は後者が約6〜7割遅く、
従って羽口の耐用寿命に大きく影響を与えること!知っ
た。しかしながら、羽口の損耗速度が遅いという点で優
位にあるArは、それ単独で用いたのではコスト的に高
価に過ぎ、又N2の単独使用は鋼中〔N〕7増加させる
ので製品の品質保持上達けなければならないことがある
。On the other hand, in the tuyeres injected with non-oxidizing gas such as Ar or N2 or reducing gas such as CO, the above-mentioned high-Fe
No wear was observed due to O slag pressure, and only wear was caused by converter slag. As a result, the difference in wear rate due to the difference between high FeO slag and converter slag is that the latter is approximately 60 to 70% slower;
Therefore, it will greatly affect the service life of the tuyere! Knew. However, Ar, which has the advantage of slowing down the wear rate of the tuyere, is too expensive to use alone, and the use of N2 alone increases [N]7 in the steel, resulting in poor product quality. There are things I need to improve on retention.
発明者らは、上記の知見に合せて、さらに第6図、第4
図に示す吹錬時の溶鉄中の成分変化並びに溶鉄温度をも
併せて検討した結果、下吹きガスとしてCO2Y用いた
場合のCO2による溶鉄の酸化反応は、高Fe0層中に
S i02が存在しないこと及び溶鉄温度が最も高くな
り溶鉄中に81が存在しないことから、吹錬中期以降に
起っていることを知り、本発明に到達したものである。In line with the above findings, the inventors further developed the
As a result of considering the compositional changes in molten iron during blowing as shown in the figure, as well as the molten iron temperature, we found that the oxidation reaction of molten iron by CO2 when CO2Y is used as the bottom blowing gas does not result in the presence of Si02 in the high Fe0 layer. Since 81 is not present in the molten iron when the temperature of the molten iron becomes the highest, it was discovered that this phenomenon occurs after the middle stage of blowing, and the present invention was developed based on this knowledge.
即ち、本発明は、溶融金属の上部よりランスにて酸素を
上吹きし底部より攪拌ガスを吹込む複合吹錬法において
、吹錬中期以降に吹込む攪拌ガスを非酸化性ガス及び/
又は還元性ガスを容積比で40〜100%含むガスとす
ることを特徴とする溶融金属精錬用ノズルにおけるガス
の吹込み方法である。That is, the present invention provides a composite blowing method in which oxygen is blown upward from the top of the molten metal using a lance and stirring gas is blown from the bottom, and the stirring gas blown after the middle stage of the blowing is replaced by a non-oxidizing gas and/or a stirring gas.
Alternatively, it is a method of blowing gas into a molten metal refining nozzle, characterized in that the gas contains 40 to 100% of reducing gas by volume.
又、上記吹錬中期以降に吹込む攪拌ガスの吹込み量を、
吹錬前期のガス吹込量の1〜6倍とすることをも特徴と
している。In addition, the amount of stirring gas blown after the middle stage of the blowing is
Another feature is that the amount of gas injected is 1 to 6 times the amount of gas in the first stage of blowing.
本発明は、複合吹錬法における下吹き羽口の耐用寿命の
向上を図り、少くとも転炉の一炉代使用することを可能
ならしめるため、下吹き攪拌ガスとして吹錬初期はコス
ト的に安価な例えばco2ヲ使用し、吹錬中期以降、先
に説明した通りCO2による溶鉄の酸化反応が起ること
を考慮し、それを避けるために吹込みガスの種類を変え
て酸化反応を起すことのない非酸化性ガス又は還元性ガ
スもしくはこれら2種を容積比で40〜100%含ませ
るものである。The present invention aims to improve the service life of the bottom blowing tuyeres in the combined blowing method, and to make it possible to use at least one converter. For example, use CO2, which is inexpensive, and take into consideration that the oxidation reaction of the molten iron due to CO2 occurs as explained earlier after the middle stage of blowing, and in order to avoid this, change the type of blowing gas to cause the oxidation reaction. It contains 40 to 100% by volume of a non-oxidizing gas or a reducing gas, or two of these gases.
この場合の、ガス種類の選択及び成分の混合比率等の決
定は、得られる鋼製品の品質に対応する如(配慮の上決
定することが必要である。In this case, the selection of the gas type, the mixing ratio of the components, etc. must be determined with consideration given to the quality of the steel product to be obtained.
又、上記のAr、 N2の如き非酸化性ガス及び/又は
CO,メタン、プロパンの茹き還元性ガスの他押抜ガス
との混合比率の下限を40%としたことの理由は、これ
未満では本発明の目的とする羽口耐用寿命を向上させる
効果が顕著に得られないからである。In addition, the reason why the lower limit of the mixing ratio of the above-mentioned non-oxidizing gases such as Ar and N2 and/or boiling reducing gases such as CO, methane, and propane as well as the punching gas is set at 40% is that the lower limit is 40%. This is because the effect of improving the useful life of the tuyere, which is the objective of the present invention, cannot be achieved significantly.
さらに、本発明方法において、吹錬末期に吹込みガス量
に1〜6倍に増加することが本発明の目的達成上好まし
いのは、この吹込みガスによる冷却能が増加し、結果と
して溶鉄の温度が最も高くなる吹錬末期に羽口耐火物の
稼動面の温度を低下させるので、高温溶鉄による酸化が
減少するからである。なお、ガス吹込み量の上限を6倍
としたのは、これを超える必要がないことによる。Furthermore, in the method of the present invention, it is preferable to increase the amount of blown gas by 1 to 6 times at the final stage of blowing in order to achieve the purpose of the present invention. This is because the temperature of the working surface of the tuyere refractory is lowered at the final stage of blowing, when the temperature is highest, so oxidation by high-temperature molten iron is reduced. The reason why the upper limit of the gas injection amount is set to six times is because there is no need to exceed this.
次の第1表は本発明方法の実施例と従来法による比較例
を示す。Table 1 below shows examples of the method of the present invention and comparative examples of the conventional method.
第1表において、羽目の平均損耗速度が1,1瓢/ch
以下である場合は転炉−炉代な通じて羽口の使用が可能
である。また参考のため羽口とガスのトータルコスト比
を示したが、Arガスのみを使用して一炉代羽口な使用
する場合に比べ本発明方法によればいずれの実施例でも
コスト面でも有利となることが理解される。このように
、本発明方法によれば高価なArを全量使用しな(ても
安価なガスで羽口を一炉代使用fることを可能ならしめ
る。In Table 1, the average wear rate of the lining is 1.1 gourd/ch.
In the following cases, it is possible to use tuyeres between the converter and the furnace. In addition, the total cost ratio of tuyere and gas is shown for reference, but the method of the present invention is advantageous in terms of cost in all embodiments compared to the case of using only Ar gas and using one tuyere for one furnace. It is understood that Thus, according to the method of the present invention, it is possible to use the tuyere for one furnace without using the entire amount of expensive Ar (although it is possible to use inexpensive gas for one furnace).
第1図は上下吹き転炉の縦断面説明図、第2図は上下吹
き転炉9羽口の一例を示す縦断面図、第6図は吹錬時の
溶鉄中の成分変化を示す線図、第4図は吹錬時の溶鉄温
度を示す線図、である。
代理人 弁理士 木 村 三 期
間 同 佐々木 宗 治
第1図
−
第2図
第4図
収ML蛸閏(k$)Figure 1 is an explanatory longitudinal cross-sectional view of a top-bottom blowing converter, Figure 2 is a vertical cross-sectional view showing an example of nine tuyeres in a top-bottom blowing converter, and Figure 6 is a diagram showing changes in components in molten iron during blowing. , FIG. 4 is a diagram showing the temperature of molten iron during blowing. Agent: Patent Attorney: Mitsu Kimura Term: Muneharu Sasaki Figure 1- Figure 2 Figure 4 Collection ML Octopus (k$)
Claims (2)
部より攪拌ガスを吹込む複合吹錬法において、吹錬中期
以降に吹込む攪拌ガスヶ非酸化性ガス及び/又は還元性
ガスを容積比で40〜100%含むガスとすることを・
特徴とする溶融金属精錬用ノズルにおけるガスの吹込み
方法。(1) In the combined blowing method, in which oxygen is blown upward from the top of the molten metal using a lance and stirring gas is blown from the bottom, the volume of the stirring gas, non-oxidizing gas and/or reducing gas that is blown in from the middle stage of blowing onwards. The gas should contain 40% to 100% of
Characteristic method of blowing gas into a molten metal refining nozzle.
、吹錬前照のガス吹込み量の1〜3倍とする特許請求の
範囲第1項記載の溶融金属精錬用ノズルにおけるガスの
吹込み方法。(2) In the molten metal refining nozzle according to claim 1, the amount of stirring gas blown after the middle stage of the blowing is 1 to 3 times the amount of gas blown before the blowing. How to blow gas.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58019622A JPS59145718A (en) | 1983-02-10 | 1983-02-10 | Blowing method of gas in nozzle for refining molten metal |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58019622A JPS59145718A (en) | 1983-02-10 | 1983-02-10 | Blowing method of gas in nozzle for refining molten metal |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS59145718A true JPS59145718A (en) | 1984-08-21 |
Family
ID=12004284
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP58019622A Pending JPS59145718A (en) | 1983-02-10 | 1983-02-10 | Blowing method of gas in nozzle for refining molten metal |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS59145718A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61143505A (en) * | 1984-12-14 | 1986-07-01 | Kawasaki Steel Corp | Refining method of high alloy steel |
JPH06147124A (en) * | 1991-06-26 | 1994-05-27 | Holset Eng Co Inc | Annular valve type air compressor with deformable annular valve |
CN110863076A (en) * | 2019-10-21 | 2020-03-06 | 河钢乐亭钢铁有限公司 | Method for maintaining bottom blowing tuyere of converter |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5822315A (en) * | 1981-08-03 | 1983-02-09 | Nippon Steel Corp | Refining process for steel by blowing co-gas |
-
1983
- 1983-02-10 JP JP58019622A patent/JPS59145718A/en active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5822315A (en) * | 1981-08-03 | 1983-02-09 | Nippon Steel Corp | Refining process for steel by blowing co-gas |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61143505A (en) * | 1984-12-14 | 1986-07-01 | Kawasaki Steel Corp | Refining method of high alloy steel |
JPH0477045B2 (en) * | 1984-12-14 | 1992-12-07 | Kawasaki Steel Co | |
JPH06147124A (en) * | 1991-06-26 | 1994-05-27 | Holset Eng Co Inc | Annular valve type air compressor with deformable annular valve |
CN110863076A (en) * | 2019-10-21 | 2020-03-06 | 河钢乐亭钢铁有限公司 | Method for maintaining bottom blowing tuyere of converter |
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