JPH03122210A - Two step counterflow refined steelmaking method using duplex converters - Google Patents
Two step counterflow refined steelmaking method using duplex convertersInfo
- Publication number
- JPH03122210A JPH03122210A JP26052589A JP26052589A JPH03122210A JP H03122210 A JPH03122210 A JP H03122210A JP 26052589 A JP26052589 A JP 26052589A JP 26052589 A JP26052589 A JP 26052589A JP H03122210 A JPH03122210 A JP H03122210A
- Authority
- JP
- Japan
- Prior art keywords
- slag
- furnace
- dephosphorization
- converter
- blowing
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 20
- 238000009628 steelmaking Methods 0.000 title claims description 11
- 239000002893 slag Substances 0.000 claims abstract description 86
- 229910052751 metal Inorganic materials 0.000 claims abstract description 43
- 239000002184 metal Substances 0.000 claims abstract description 43
- 238000007670 refining Methods 0.000 claims abstract description 32
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 claims abstract description 24
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 21
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 21
- 239000010959 steel Substances 0.000 claims abstract description 21
- 239000010436 fluorite Substances 0.000 claims abstract description 19
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 14
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000007789 gas Substances 0.000 claims abstract description 12
- 238000003756 stirring Methods 0.000 claims abstract description 9
- 238000007664 blowing Methods 0.000 claims description 45
- 238000005261 decarburization Methods 0.000 claims description 32
- 238000009749 continuous casting Methods 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 6
- 229910001882 dioxygen Inorganic materials 0.000 claims description 6
- 230000003197 catalytic effect Effects 0.000 claims description 3
- 239000002131 composite material Substances 0.000 claims description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 47
- 229910052742 iron Inorganic materials 0.000 abstract description 23
- 229910001634 calcium fluoride Inorganic materials 0.000 abstract description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 2
- 229910052760 oxygen Inorganic materials 0.000 abstract description 2
- 239000001301 oxygen Substances 0.000 abstract description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract 3
- 229910052593 corundum Inorganic materials 0.000 abstract 3
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract 3
- 238000005266 casting Methods 0.000 abstract 1
- 238000005262 decarbonization Methods 0.000 abstract 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 24
- 239000000292 calcium oxide Substances 0.000 description 12
- 235000012255 calcium oxide Nutrition 0.000 description 12
- 230000000694 effects Effects 0.000 description 12
- 239000011572 manganese Substances 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 7
- 230000004907 flux Effects 0.000 description 6
- 230000001737 promoting effect Effects 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 4
- 238000006477 desulfuration reaction Methods 0.000 description 4
- 230000023556 desulfurization Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000010459 dolomite Substances 0.000 description 4
- 229910000514 dolomite Inorganic materials 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 229910000616 Ferromanganese Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000013019 agitation Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910000805 Pig iron Inorganic materials 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 2
- 239000011449 brick Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 238000010079 rubber tapping Methods 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 101100348017 Drosophila melanogaster Nazo gene Proteins 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000012768 molten material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Landscapes
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
この発明は、全製鋼工程を通じた造滓剤使用量を極力抑
えつつ安定した高能率脱燐を行い、品質の良好な鋼をコ
スト安く溶製する方法に関するものである。[Detailed Description of the Invention] <Industrial Application Field> This invention performs stable and highly efficient dephosphorization while minimizing the amount of slag-forming agent used throughout the entire steelmaking process, and melts high-quality steel at low cost. It relates to a method of manufacturing.
（従来技術とその課題〉
近年、各種鋼材に対する高度な品質要求と低価格要求に
対応するため、例えば低Ｆ、鋼をより一層低いコストで
安定溶製する手段等の開発に多大な努力が払われている
が、このような状況下において、本出願人は先に、全製
鋼工程を通じて造滓剤（生石灰等）の使用量を極力抑え
つつ高能率脱燐が行えるところの、［溶銑の精錬に当っ
て、第２図に示した如く、上下両吹き機能を有した２基
の転炉形式の炉を使用し、かつその一方を脱燐炉１、他
方を脱炭炉２として、前記脱燐炉１内へ注入した溶銑３
に前記脱炭炉２で発生した転炉滓４を主成分とする精錬
剤４′（転炉滓は熔融状態又は固化状態の何れで用いて
も良い）を添加すると共に、撹拌ガス吹込みノズル５を
用いた底吹きガス撹拌を行いつつランス６にて酸素ガス
を上吹きすることで所要溶銑温度を保ちながら溶銑脱燐
を行い、次いで得られた脱燐溶銑を脱炭炉２にて脱炭並
びに仕上脱燐することから成る“脱燐スラグ−メタルの
２段階向流接触精錬を伴う製鋼方法”」 を提案しく特
開昭６２−２９０８１５号）、Ｐ含有量の低い高品質鋼
を少ない造滓剤使用量の下で安価に提供し得る道を開い
た。(Prior art and its issues) In recent years, in order to meet the high quality requirements and low price requirements for various steel materials, great efforts have been made to develop low F, stable melting methods for steel at even lower costs. However, under these circumstances, the applicant has previously proposed a process called [Hot Metal Refining], which can achieve highly efficient dephosphorization while minimizing the amount of slag-forming agents (quicklime, etc.) used throughout the entire steelmaking process. As shown in Fig. 2, two converter-type furnaces with both upper and lower blowing functions are used, and one of them is used as a dephosphorization furnace 1 and the other as a decarburization furnace 2. Hot metal 3 injected into phosphor furnace 1
A refining agent 4' mainly composed of converter slag 4 generated in the decarburization furnace 2 (the converter slag may be used in either a molten state or a solidified state) is added to the decarburizer 2, and a stirring gas injection nozzle is added to the refining agent 4'. The hot metal is dephosphorized while maintaining the required hot metal temperature by top-blowing oxygen gas through the lance 6 while bottom-blowing gas stirring is performed using the dephosphorization furnace 2. We propose a "steel manufacturing method involving two-stage countercurrent contact refining of dephosphorized slag-metal" consisting of charcoal and final dephosphorization (Japanese Patent Application Laid-Open No. 62-290815), which reduces the amount of high-quality steel with low P content. This paved the way for low-cost production of sludge with reduced usage levels.
つまり、本出願人の提案になる上記製鋼方法は、「溶銑
の転炉脱炭精錬に先立って、脱炭炉とは別の“上下両吹
き機能を有する複合吹錬転炉”を精錬容器とした予備脱
燐処理、それも脱炭炉で発生した転炉スラグを脱燐剤と
した脱燐処理を実施すると、この脱燐処理では
ａ）酸素ガスの吹込みを極めて容易かつ調節自在に実施
することができるので、処理温度の調整・維持が格別な
配慮を要することなく十分な余裕下で簡単・適切に行え
る。In other words, the above-mentioned steelmaking method proposed by the present applicant requires that ``prior to the decarburization of hot metal in a converter, a ``combined blowing converter having both upper and lower blowing functions,'' which is separate from the decarburizer, is used as a refining vessel. In this dephosphorization process, a) injection of oxygen gas can be carried out extremely easily and freely; Therefore, the processing temperature can be easily and appropriately adjusted and maintained with sufficient margin without requiring special consideration.
ｂ）底吹きガス撹拌により、単なる溶銑処理鍋を使用し
た炉外精錬ででは達成することの出来ない十分な被処理
溶銑の撹拌が行える。b) Bottom-blown gas agitation allows for sufficient agitation of the molten metal to be treated, which cannot be achieved by out-of-furnace refining using a simple molten metal processing pot.
Ｃ）スラグフォーミングに十分対処できるだけの余裕の
あるフリーボード（場面から容器上端までの距離）が確
保できるので、反応性に冨んだ転炉スラグの大胆な使用
が可能である。C) Since a free board (distance from the scene to the top of the container) with sufficient margin to deal with slag foaming can be secured, bold use of highly reactive converter slag is possible.
ｄ）転炉では塩基性ライニングが施されているためスラ
グによる耐火物の溶損を極力軽減でき、脱燐作業能率を
上げ得る大胆な操業が可能である。d) Since the converter is equipped with a basic lining, erosion of the refractories by slag can be minimized, and bold operations that can increase dephosphorization efficiency are possible.
ｅ）排滓を極めて容易かつ十分に行えるので脱燐能率が
顕著に向上する。e) Since the slag can be removed very easily and thoroughly, the dephosphorization efficiency is significantly improved.
ｆ）構造的に十分な排ガス処理設備（集塵機）設置が裏
付けられているので、高品質鋼の作業性の良い大量処理
が可能である。f) Since the installation of structurally sufficient exhaust gas treatment equipment (dust collector) is supported, it is possible to process high-quality steel in large quantities with good workability.
等の機能・作用が相乗され、 “全製鋼工程を通じた造
滓剤使用量”を極めて少ない値に抑えつつ高い脱燐効率
で品質の優れた鋼を量産することが可能になる」との新
知見事実に基づいて確立されたものであり、次のような
効果を享受できるものであった。即ち、
）脱炭・仕上げ脱燐吹錬で発生した転炉滓を溶銑脱燐フ
ラックスとして用いる“向流精錬”であるため、全製鋼
工程での生石灰使用量がそれまでのトーピードや溶銑鍋
を使用した炉外脱燐処理に比べて大幅に減少し、低ｆ４
ｆｉ４を極めて少ない生石灰量で吹錬することを可能と
する。従って、処理能率や以下に示す効果等をも併せて
考慮すれば、脱燐容器として複合吹錬転炉を使用したと
しても上記従来法に比べて十分な経済的有利性を確保で
き、更に遊休の現有転炉を使用すればコストメリットは
一段と向上する。These functions and effects are synergized, making it possible to mass-produce high-quality steel with high dephosphorization efficiency while keeping the amount of slag-forming agent used throughout the entire steelmaking process to an extremely low value. It was established based on knowledge and facts, and the following effects could be enjoyed. In other words, since it is a "countercurrent refining" method in which the converter slag generated during decarburization and final dephosphorization blowing is used as hot metal dephosphorization flux, the amount of quicklime used in the entire steelmaking process is lower than that of the conventional torpedo and hot metal ladle. This is significantly reduced compared to the outside-furnace dephosphorization treatment used, resulting in low f4
It is possible to blow fi4 with an extremely small amount of quicklime. Therefore, if processing efficiency and the following effects are also taken into account, even if a composite blowing converter is used as a dephosphorization vessel, sufficient economic advantages can be secured compared to the conventional method described above, and furthermore, If existing converters are used, the cost benefits will be further improved.
ｉｉ）転炉滓中のＦｅＯの有効利用がなされ、粒鉄や地
金の回収率が向上する。ii) FeO in the converter slag is effectively utilized, improving the recovery rate of granulated iron and metal.
ｉｉｉ ）一般に、脱炭炉でマンガン鉱石や鉄マンガン
鉱石を使用した場合にはこれらの約半分はＭｎにまで還
元されずに酸化物としてスラグ中に残るが、この方法に
おいては、該スラグを溶銑脱燐フラックスとして再使用
するので上記残留鉱石の有効利用がなされ、溶銑におけ
る“［Ｍｎ］ロスの軽減”或いは“［Ｍｎ］上昇”に役
立つ。iii) Generally, when manganese ore or ferromanganese ore is used in a decarburization furnace, about half of these ores are not reduced to Mn and remain in the slag as oxides, but in this method, the slag is converted into hot metal. Since it is reused as a dephosphorization flux, the residual ore is effectively utilized and is useful for "reducing [Mn] loss" or "increasing [Mn]" in hot metal.
ｉｖ）使用する炉が転炉であるので、例えば脱燐炉の場
合でも、出鋼口から脱燐銑のみを鍋中へ出銑してから炉
内のスラグを溶滓鍋に排出でき、他の脱燐法におけるよ
りも除滓が簡単でかつ高脱燐率を確保できる。iv) Since the furnace used is a converter, even in the case of a dephosphorization furnace, only the dephosphorized pig iron can be tapped from the tapping port into the ladle, and then the slag in the furnace can be discharged into the slag ladle, and other It is easier to remove slag than in the other dephosphorization methods, and a high dephosphorization rate can be ensured.
■）使用する炉が上下両吹き機能を有した転炉であるの
で溶銑の強撹拌が出来て短時間処理が可能となるので抜
熱量が少なく、他の脱燐処理法に比して熱経済上極めて
有利である。特に溶融転炉滓を用いる場合にはその顕熱
分だけ更に熱経済的に有利となる。■) Since the furnace used is a converter with both upper and lower blowing functions, the hot metal can be strongly stirred and the treatment can be carried out in a short time, so the amount of heat removed is small and it is thermoeconomical compared to other dephosphorization treatment methods. This is extremely advantageous. In particular, when melting converter slag is used, it becomes more thermoeconomically advantageous due to its sensible heat.
ｖｉ）上記脱燐炉で発生するスラグは、ＰｚＯｓ含有量
が４〜１０％にもなっているので肥料としての用途が開
ける上、遊離石灰が無いため路盤材としての有効利用も
可能である。vi) The slag generated in the above-mentioned dephosphorization furnace has a PzOs content of 4 to 10%, so it can be used as fertilizer, and since there is no free lime, it can also be effectively used as a roadbed material.
ｖｉ）使用する炉が２つであるので、炉体に付着するＰ
２Ｏ，に起因した脱燐不良の懸念がない。vi) Since two furnaces are used, P adhering to the furnace body
There is no concern about poor dephosphorization caused by 2O.
つまり、脱燐炉では高Ｐ２０．のスラグが、そして脱炭
炉では低Ｐ２０．スラグしか付着しないので脱炭炉での
脱燐不良が起こらない。しかも、溶融転炉滓を使用する
場合には、脱燐炉では溶銑を装入した後に溶融転炉滓が
入れられるので、急激な爆発的反応が起きる心配がなく
、成る程度激しい反応が起きたとしても処理容器が転炉
であるので格別な不都合を招く恐れも少ない。In other words, the dephosphorization furnace has a high P20. slag, and low P20 in the decarburization furnace. Since only slag is attached, no dephosphorization failure occurs in the decarburization furnace. Moreover, when using molten converter slag, the molten converter slag is charged into the dephosphorization furnace after the hot metal is charged, so there is no need to worry about a sudden explosive reaction occurring, and only a violent reaction could occur. However, since the processing vessel is a converter, there is little risk of causing any particular inconvenience.
輔）底吹きガス撹拌を行いつつ脱燐を行うので、これま
での溶銑脱燐法の場合のように脱燐剤を粉状近くにまで
細かく粉砕しておく必要がなく、その分のコスト低減が
可能となる。輔）Since dephosphorization is performed while stirring bottom-blown gas, there is no need to finely grind the dephosphorizing agent to near powder form as in the case of conventional hot metal dephosphorization methods, which reduces costs accordingly. becomes possible.
ｉｘ）遊休転炉がある場合には、これを直ちに脱燐炉と
して使うことが出来、格別な設備を準備する必要がない
。また、例えば転炉１／２基操業を行っている工場の場
合には一方の炉を脱燐炉とすることにより転炉２／２基
操業のような形態を採ることができ、新たな設備投資を
必要としない。ix) If there is an idle converter, it can be used immediately as a dephosphorization furnace, and there is no need to prepare special equipment. In addition, for example, in the case of a factory that operates 1/2 converter furnaces, one furnace can be used as a dephosphorization furnace to operate 2/2 converter furnaces, and new equipment can be used. No investment required.
そして、レンガ寿命のために何れか一方を築炉する必要
が生じた場合には、この間だけ転炉１基のみで従来の転
炉吹錬を行って遊体炉を出さない方策も講じられ、非常
に柔軟性に冨んだ精錬が可能である。If it becomes necessary to construct one of the bricks to extend the lifespan of the bricks, measures are taken to carry out conventional converter blowing using only one converter during this time and to avoid using a free furnace. Very flexible refining is possible.
ところが、本発明者等は、数多くの実際操業実績の仔細
な分析を通して「２基の複合吹錬転炉を用いた２段向流
精錬は従来のトーピードや溶銑鍋を使用した炉外精錬に
比べての利点が十分に認められはするものの、それでも
時々に応じて鉄分ロスにバラツキが見られる上、到達Ｐ
レベルにも多少の不安定性が現れがちである」との事実
を認識したのである。However, through detailed analysis of numerous actual operational results, the present inventors found that ``two-stage countercurrent refining using two combined blowing converters is superior to conventional out-of-furnace refining using a torpedo or hot metal pot.'' Although the benefits of iron loss are well recognized, there are still variations in iron loss depending on the situation, and the attainment of P
They recognized the fact that there is a tendency for some level of instability to appear.
そこで、上記鉄分ロスや到達Ｐレベルのバラツキを抑え
て“２基の複合吹錬転炉を用いた２段向流精錬”の操業
性をより一層安定化させるべく研究を続け、［鉄分ロス
のバラツキは脱燐炉での脱燐精錬時に主として生じるも
のであり、特にその時の精錬スラグ中ＣａＦｚ割合が極
めて重要な役割を果たしていて、蛍石の投入により該精
錬スラグ中のＣａＦ２割合を高めに調整すると鉄分ロス
の抑制が効果的になされる」との知見を得たことを基に
“吹錬後スラグ中の（：、ａＦｔ割合を高めた脱燐操業
”を試みた。Therefore, we continued our research to further stabilize the operability of "two-stage countercurrent refining using two combined blowing converters" by suppressing the above-mentioned iron loss and variation in the achieved P level. The variation mainly occurs during dephosphorization refining in the dephosphorization furnace, and the CaFz ratio in the refined slag at that time plays an extremely important role, and the CaF2 ratio in the refined slag can be adjusted to a higher level by adding fluorite. Based on the knowledge that "this effectively suppresses iron loss," we attempted a "dephosphorization operation that increases the ratio of aFt in the slag after blowing."
しかしながら、上記“蛍石投入による高Ｃａ Ｆ、スラ
グ脱燐吹錬”では滓化促進及びスラグ流動性改善効果に
よって確かに鉄分ロスの低い安定した操業を維持するこ
とができるが、溶銑［Ｓｉ］？Ｍ度に応じて鉄分ロス少
なく所望脱燐を行うために必要な蛍石投入量を示した第
３図からも明らかなように、上記好ましい操業状態を維
持するには蛍石の多量投入を要することとなって、“２
基の複合吹錬転炉を用いた２段向流精錬”が特徴とする
「操業コストの低減」に悪影響を及ぼすことが懸念され
た。However, the above-mentioned "high Ca F, slag dephosphorization blowing by adding fluorite" can certainly maintain stable operation with low iron loss due to the effects of promoting slag formation and improving slag fluidity. ? As is clear from Figure 3, which shows the amount of fluorite input necessary to perform the desired dephosphorization with less iron loss depending on the M degree, a large amount of fluorite is required to maintain the above-mentioned preferable operating conditions. As a result, “2
There were concerns that this would have a negative impact on the ``reduction of operating costs,'' which is a characteristic of ``two-stage countercurrent refining using a composite blowing converter.''
このようなことから、本発明が目的としたのは、“２基
の複合吹錬転炉を用いた２段向流精錬”を実施するに際
して、コスト高につながる蛍石の多量投入を行わな（で
もスラグへの鉄分ロスの少ない効果的な脱燐を行うこと
ができる手段を見出し、品質の優れた綱をより安定した
操業性の下で安価に溶製し得る製鋼法を確立することで
あった。For this reason, the purpose of the present invention is to avoid introducing a large amount of fluorite, which would lead to high costs, when implementing "two-stage countercurrent refining using two combined blowing converters." (However, by finding a method for effective dephosphorization with less loss of iron to slag, and establishing a steel manufacturing method that can produce high-quality steel at a low cost with more stable operability. there were.
〈課題を解決するための手段〉
本発明者は、上記目的を達成すべく種々の観点から研究
を重ねたところ、更に「連続鋳造（ＣＣ）や造塊時の脱
酸滓たるスラグやＭ精錬で発生するアルミドロス（アル
ミ灰）には多量のｐＪ１２０３が含まれているが、この
Ａｌｌ ｚ Ｏ３には蛍石の主成分であるＣａＦ２と同
様なＣａＯ系フラックスの滓化促進作用があり、前記“
２基の複合吹錬転炉を用いた２段向流精錬”における脱
炭炉吹錬の際に該ＣＣ・造塊滓又はアルミドロスを脱炭
炉内に添加して精錬を行うと、発生する転炉滓には相当
量のＡ１□０３が含有されることとなって、これを用い
る脱燐炉精錬時に蛍石の使用量を少なくしても十分な滓
化促進及びスラグ流動性改善効果が確保されて鉄分ロス
の低い安定した操業が維持されるようになる」との新し
い知見を得るに至った。<Means for Solving the Problems> The present inventor has repeatedly conducted research from various viewpoints to achieve the above object, and has further discovered that slag, which is deoxidized slag during continuous casting (CC) and ingot making, and M smelting. The aluminum dross (aluminum ash) generated in the process contains a large amount of pJ1203, but this All z O3 has the same effect of promoting slag formation of CaO-based flux as CaF2, which is the main component of fluorite. “
If the CC, agglomerate slag or aluminum dross is added to the decarburization furnace during decarburization furnace blowing in ``two-stage countercurrent refining using two combined blowing converters,'' Since the converter slag contains a considerable amount of A1□03, even if the amount of fluorite used during dephosphorization furnace smelting is reduced, the effect of promoting slag formation and improving slag fluidity is sufficient. This will ensure stable operation with low iron loss."
本発明は、上記知見事項等に基づいてなされたものであ
り、
「上下両吹き機能を有した２基の転炉形式〇炉のうちの
一方を脱燐炉、他方を脱炭炉とし、前記脱燐炉内へ注入
した溶銑に脱炭炉で発生した転炉滓を主成分とする精錬
剤を添加して脱燐スラグ−メタルの２段階向流接触精錬
を行う製鋼法において、第１図に示すように、前記転炉
滓として脱炭炉中にＣＣ・造塊滓もしくはアルミドロス
添加を行って発生したものを使用すると共に、脱燐炉内
へ添加する前記転炉滓を主成分とした精錬剤中に蛍石を
含有させて生成スラグ中の（ＣａＦｚ ＋ ＡｌｚＯ３
）割合を１０〜２０重量％に調整し、かつ底吹きガス撹
拌を行いつつ酸素ガスを上吹きして溶銑温度を１４００
℃以下に保ちながら溶銑脱燐を行い、得られた脱燐溶銑
を脱炭炉に注銑して脱炭並びに仕上脱燐することにより
、鉄分ロスや生石灰の使用量少なく品質の良好な低燐鋼
を安価に製造し得るようにした点」
に特徴を有するものである。The present invention has been made based on the above-mentioned findings, etc., and consists of two converter type furnaces having both upper and lower blowing functions, one of which is a dephosphorization furnace and the other a decarburization furnace. Figure 1 shows a steelmaking method in which a refining agent mainly composed of converter slag generated in a decarburization furnace is added to hot metal injected into a dephosphorization furnace to perform two-step countercurrent catalytic refining of dephosphorization slag and metal. As shown in , the converter slag is generated by adding CC, agglomerate slag or aluminum dross into the decarburization furnace, and the converter slag added to the dephosphorization furnace is used as the main component. (CaFz + AlzO3
) Adjust the ratio to 10 to 20% by weight, and top blow oxygen gas while bottom blowing gas stirring to bring the hot metal temperature to 1400.
By dephosphorizing the hot metal while keeping the temperature below ℃, and pouring the obtained dephosphorized hot metal into a decarburization furnace for decarburization and final dephosphorization, we can produce low phosphorus with good quality and less iron loss and quicklime usage. It is characterized by the fact that steel can be manufactured at low cost.
く作用〉
さて、精錬剤に配合される蛍石は、第４図に示されるよ
うに、その主成分たるＣａＦ２の作用によってＣａＯ系
フランクスの滓化促進及びスラグ流動性改善効果を発揮
するが、第５図に示される如くＡｆ ｚ Ｏ３も前記Ｃ
ａＦｚと同様にＣａＯ系フランクスの滓化を促進しスラ
グ流動性を改善する作用を有している。また、連続鋳造
や造塊時に発生するスラグやＡＩ精錬で発生するアルミ
ドロス（アルミ灰）には主成分としてＡＮ ２０ 、が
含まれているので、脱炭炉吹錬の際に通常使用される媒
溶剤と共に前記ＣＣ・造塊滓又はアルミドロスをも添加
して吹錬を行うと、ＡＩ□０３分に富んだ転炉滓が発生
する。従って、“２基の複合吹錬転炉を用いた２段向流
精錬”に際し、脱燐炉内へ添加する精錬剤として前記Ａ
Ｉ！ ｚ Ｏｓ分に富んだ転炉滓を主成分とするものを
用いれば、蛍石の配合量を低減したとしてもこの分がＣ
Ｃ・造塊滓等からのＡｉ！ ２０３によって補償され、
スラグへの鉄分ロスを抑える十分な効果がコスト安く確
保できるようになる。As shown in Figure 4, fluorite mixed in the refining agent has the effect of promoting slag formation of CaO-based franks and improving slag fluidity due to the action of its main component, CaF2. As shown in FIG. 5, Af z O3 is also
Like aFz, it has the effect of promoting slag formation of CaO-based franks and improving slag fluidity. In addition, slag generated during continuous casting and ingot making and aluminum dross (aluminum ash) generated during AI refining contain AN20 as a main component, so it is usually used during decarburization furnace blowing. When blowing is performed by adding the CC/agglomerate slag or aluminum dross together with the solvent, converter slag rich in AI□03 is generated. Therefore, when performing "two-stage countercurrent refining using two combined blowing converters", the above-mentioned A
I! If a material whose main component is converter slag rich in Os is used, even if the amount of fluorite blended is reduced, this amount will be reduced to C.
C. Ai from agglomerate slag, etc.! Compensated by 203,
A sufficient effect of suppressing iron loss to slag can be achieved at a low cost.
ただ、この場合、脱燐炉にて生成されるスラグのＣＣａ
Ｆ、 ＋ Ｈアｏｉ）割合が１０重量％未満では十分な
滓化が確保できないために鉄分ロスの抑制が不安定とな
り、一方、スラグ中（ＣａＦ ｚ＋Ａｊ！ｚ０３）の割
合が２０重量％を超えてもそれ以上の鉄分ロス改善効果
が得られないばかりか、蛍石消費量増大によるコストア
ップ並びに耐火物の溶損が著しくなることから、脱燐炉
で生成されるスラグ中の（Ｃａ Ｆ ｚ ＋ Ａｌｔｏ
３）割合が１０〜２０重量％となるように脱炭炉へ添
加するアルミドロスや脱炭炉へ添加する蛍石の量を調整
することと定めた。However, in this case, the CCa of the slag produced in the dephosphorization furnace
If the ratio of (CaF z+Aj!z03) in the slag is less than 10% by weight, sufficient slag formation cannot be ensured, making suppression of iron loss unstable; However, not only is it not possible to obtain any further iron loss improvement effect, but also the cost increases due to increased fluorite consumption, and the melting of refractories becomes significant. +Alto
3) It was decided that the amount of aluminum dross added to the decarburization furnace and the amount of fluorite added to the decarburization furnace should be adjusted so that the ratio was 10 to 20% by weight.
このように、脱燐炉で使用される精錬剤は“ＣＣ・造塊
滓又はアルミドロスを添加した脱炭吹錬炉で発生する転
炉滓”を主成分とし蛍石を基本の副成分として配合した
ものであるが、転炉滓を滓化性のより向上させて低融点
の脱燐スラグとしたり脱燐が進行し易いようにスラグの
酸化力を高めるためには、上記成分の他に酸化鉄の併用
も好ましい。更に、これらの成分以外に生石灰、ドロマ
イト或いは石灰石を付加的に配合しても良いし、溶銑［
Ｍｎ］向上のためにマンガン鉱石や鉄マンガン鉱石を配
合しても良い。また、媒溶剤として螢石以外にＣａ（Ｊ
２． ＮａｚＯ＝ＳｉＯｔ＋ ＮａｚＣＯ：＋等を添加
して良いことも勿論である。In this way, the refining agent used in the dephosphorization furnace is mainly composed of "converter slag generated in the decarburization blowing furnace to which CC/agglomerate slag or aluminum dross is added" and fluorite as the basic subcomponent. In addition to the above ingredients, in order to improve the converter slag's slagging ability and turn it into dephosphorizing slag with a low melting point, or to increase the oxidizing power of the slag so that dephosphorization can proceed easily, it is necessary to add It is also preferable to use iron oxide in combination. Furthermore, quicklime, dolomite, or limestone may be additionally blended in addition to these ingredients, and hot metal [
Manganese ore or ferromanganese ore may be added to improve Mn]. In addition to fluorite as a solvent, Ca(J
2. Of course, it is also possible to add NazO=SiOt+ NazCO:+ or the like.
脱燐炉で使用される精錬剤の主成分たる転炉滓としては
、脱炭炉で発生した溶融状態のものが熱経済的にも脱燐
フラックスの滓化性の面からも好ましいが（このように
溶融状態のものを用いる場合には耐火物を内張すした鍋
を介して脱燐炉に江津される）、取り扱いの容易さ等を
考慮して脱炭炉で得られたものを一旦冷却凝圃させ、粒
状又は塊状に破砕してから用いても良い。なお、使用さ
れる転炉滓は、タイミングとしては前回チャージのもの
が良いが、それ以前に脱炭炉がら出たものや他の工場の
脱炭炉で発生したものでも良いことは言うまでもない。As the converter slag, which is the main component of the refining agent used in the dephosphorization furnace, the molten slag generated in the decarburization furnace is preferable from the viewpoint of thermoeconomics and slag formation of the dephosphorization flux. (When using a molten material, it is passed through a refractory-lined pot to a dephosphorization furnace); however, considering ease of handling, the material obtained in a decarburization furnace is It may be used after being cooled and solidified and crushed into granules or chunks. It should be noted that the timing of the converter slag to be used is preferably that from the previous charge, but it goes without saying that it may also be one that came out of the decarburization furnace before that or one that was generated in a decarburization furnace at another factory.
脱燐炉での処理温度を１４００”Ｃ以下に調整する理由
は、溶銑処理温度がこれより高くなると脱炭ばかりが進
行してスラグ中の全Ｆｅ量が低くなって脱燐率が悪化す
ることにある。一方、前記温度が余りに低温になると、
今度はスラグへの粒鉄ロスが増加するので好ましくない
。従って、脱燐炉での処理温度は１４００’Ｃ以下と定
めたが、好ましくは１２００〜１４００℃、出来れば１
２５０〜１３７０℃に調整するのが良い。そして、この
ような処理温度の維持は上吹きランスからの酸素ガス吹
き込み或いは炉底羽口からの酸素ガス吹き込み、更には
アルミ灰酸化時の燃焼熱の併用によって行われる。The reason why the treatment temperature in the dephosphorization furnace is adjusted to 1400"C or less is that if the hot metal treatment temperature is higher than this, decarburization will proceed, the total amount of Fe in the slag will decrease, and the dephosphorization rate will worsen. On the other hand, if the temperature becomes too low,
This is not preferable because the loss of granular iron to the slag increases. Therefore, the treatment temperature in the dephosphorization furnace was set at 1400°C or lower, preferably 1200 to 1400°C, preferably 1
It is best to adjust the temperature to 250-1370°C. The treatment temperature is maintained by blowing oxygen gas from the top blowing lance or from the bottom tuyere, and by using combustion heat during oxidation of aluminum ash.
従って、ここでの上吹き酸素ランスは通常の転炉ランス
でも良いが、脱燐用に新作した小流量ランスであっても
良い。そして、使用酸素ガス量は処理前の溶銑温度や珪
素含有量、転炉滓の温度。Therefore, the top blowing oxygen lance here may be a normal converter lance, but it may also be a new small flow rate lance for dephosphorization. The amount of oxygen gas used depends on the temperature of the hot metal before treatment, the silicon content, and the temperature of the converter slag.
脱燐炉の温もり具合、目的とする処理溶銑温度等によっ
て決定されるが、概ね２ＯＮｎｆ／Ｔ以下で良く、通常
は５〜１ＯＮｒｒｒ／Ｔが効果的である。因に、このと
きの脱炭量は０．５％程度である。Although it is determined by the warmth of the dephosphorization furnace, the target temperature of the hot metal to be treated, etc., it is generally not more than 2 ONnf/T, and usually 5 to 1 ONrrr/T is effective. Incidentally, the amount of decarburization at this time is about 0.5%.
炉底から吹き込む撹拌ガスとしてはＡｒ、ＣＯ□。The stirring gases blown from the bottom of the furnace are Ar and CO□.
ＣＯ，Ｎ、、Ｏ！＋空気等の何れであっても良い。CO, N,,O! + Air, etc. may be used.
そして、脱燐炉の炉底ガス撹拌の程度は通常の上下両吹
き複合吹錬におけると同程度（０，０３〜０．２ＮｒＪ
／ｍ１ｎ−Ｌ）で良いが、脱燐速度の向上を狙ってこれ
よりも更に多くして良いことは勿論である。The degree of agitation of the bottom gas in the dephosphorization furnace is the same as in normal double blowing combined blowing (0.03 to 0.2NrJ).
/m1n-L), but it is of course possible to increase the amount even more with the aim of improving the dephosphorization rate.
脱炭炉での吹錬は、ＣＣ・造塊滓又はアルミドロスを添
加する他は基本的には通常の６炉外で脱燐された溶銑”
を吹錬する場合と同じであり、このとき終点での溶鋼の
Ｍｎ含有量向上を目的として生石灰やドロマイトを中心
とする造滓剤の他にマンガン鉱石や鉄マンガン鉱石を添
加することもできる。ところで、本発明に係る製鋼法を
実施する場合には、出来れば適用される溶銑の事前脱硫
処理を行うのが良い。なぜなら、該製鋼法では脱硫の進
行が極めて鈍いことが挙げられるが、この他、事前脱硫
していない溶銑を用いた場合には転炉スラグ中のＳ含有
量が上昇し、次のチャージにおける溶鋼Ｓ含有量を高め
ることも懸念されるからである。なお、前記事前脱硫は
通常行われている溶銑脱硫方法のいずれによっても良い
。更に、この方法に適用される原料溶銑のＳｉ含有量も
低い程好ましい。Blowing in a decarburizing furnace is basically hot metal that has been dephosphorized outside the ordinary 6 furnaces, except for the addition of CC, agglomerate slag, or aluminum dross.
This is the same as when blowing, and at this time, manganese ore or ferromanganese ore can be added in addition to a slag-forming agent mainly composed of quicklime and dolomite for the purpose of increasing the Mn content of the molten steel at the end point. By the way, when implementing the steel manufacturing method according to the present invention, it is preferable to perform a preliminary desulfurization treatment on the applied hot metal if possible. This is because desulfurization progresses extremely slowly in this steelmaking method, but in addition to this, when hot metal that has not been desulfurized in advance is used, the S content in the converter slag increases, and the molten iron in the next charge increases. This is because there is also concern about increasing the S content. Note that the preliminary desulfurization may be performed by any of the commonly used hot metal desulfurization methods. Furthermore, the lower the Si content of the raw material hot metal used in this method, the better.
次に、この発明を実施例により具体的に説明する。Next, the present invention will be specifically explained using examples.
〈実施例〉
まず、ＫＲ（溶銑処理炉）で脱硫処理した第１表の上段
に示される成分組成の溶銑２５０トンを脱燐炉として使
用する上下両吹き複合吹錬転炉に注銑し、これに、“同
様形式の脱炭炉へ通常媒溶剤の他に出鋼から連続鋳造及
び造塊作業で生じたスラグ１０ｋｇ／Ｔを添加しての吹
錬で発生した転炉滓”２５ｋｇ／７． １００鶴以下の
粒径の鉄鉱石６ ｋｇ／Ｔ。<Example> First, 250 tons of hot metal having the composition shown in the upper row of Table 1, which had been desulfurized in a KR (hot metal processing furnace), was poured into an upper and lower double blowing combined blowing converter used as a dephosphorization furnace. To this, 25 kg/7 slag of converter generated by blowing in a similar type of decarburization furnace by adding 10 kg/T of slag generated from tapping, continuous casting, and ingot-making operations in addition to a normal solvent. ．． 6 kg/T of iron ore with a particle size of 100 Tsuru or less.
生石灰６ ｋｇ／Ｔ並びに螢石５ ｋｇ／Ｔを添加して
１０分間の脱燐処理を行った。なお、この時のスラグ中
（Ｃａ Ｆ ｔ 十Ａ１ｔＯａ）割合は１４重量％であ
った。6 kg/T of quicklime and 5 kg/T of fluorite were added and dephosphorization was performed for 10 minutes. Incidentally, the proportion of Ca F t in the slag at this time (Ca F t +A1tOa) was 14% by weight.
ところで、使用した脱燐炉並びに脱炭炉は、上述のよう
に何れも炉底よりガス吹き込み撹拌が可能な１６０トン
上下両吹き複合吹錬転炉であり、以下の何れの実施例に
おいても第２表に示すような操業条件が採用された。By the way, the dephosphorization furnace and decarburization furnace used were both 160-ton top and bottom double blowing combined blowing converters capable of blowing gas and stirring from the bottom of the furnace, as described above. The operating conditions shown in Table 2 were adopted.
このようにして得られた脱燐銑（成分組成は第１表の中
段に示す）を−旦鍋中に出銑してから脱炭炉に注銑し、
通常の転炉操業通りに生石灰７ｋｇ／Ｔ、軽焼ドロマイ
ト５ｋｇバ並びに珪砂２ｋｇバとを造滓剤として主吹錬
を実施した。なお、この際、終点温度（吹錬終了温度）
が１６７０℃となるように冷却材としての鉄鉱石及びマ
ンガン鉱石を適時添加した。The dephosphorized pig iron thus obtained (the composition is shown in the middle row of Table 1) was tapped into a hotpot and then poured into a decarburization furnace.
Main blowing was carried out using 7 kg/T of quicklime, 5 kg of lightly calcined dolomite, and 2 kg of silica sand as slag-forming agents in accordance with normal converter operation. In addition, at this time, the end point temperature (blowing end temperature)
Iron ore and manganese ore were added as coolants at appropriate times so that the temperature was 1670°C.
そして、このとき発生した転炉滓を鉄鉱石及び螢石と共
に再び次のチャージの脱燐剤原料として脱燐炉に添加し
て脱燐を行うと言う一連の操作を繰り返した。Then, a series of operations were repeated in which the converter slag generated at this time was added to the dephosphorization furnace together with iron ore and fluorite as a dephosphorizing agent raw material for the next charge to perform dephosphorization.
この結果、全製鋼工程での生石灰使用量と軽焼ドロマイ
ト使用量との和が１８ｋｇ／Ｔと言う少ない値で、第１
表の下段に示す如き鋼中Ｐ量が０．０１０重量％の溶鋼
を安定した操業下で得ることができた。As a result, the sum of the amount of quicklime used and the amount of light burnt dolomite used in the entire steelmaking process was a small value of 18 kg/T, and the first
Molten steel with a P content of 0.010% by weight as shown in the lower part of the table could be obtained under stable operation.
〈効果の総括〉
以上に説明した如く、この発明によれば、製鋼工程の全
体を通じた造滓剤使用量やスラグへの鉄分ロスを低く抑
えながら品質の良好な鋼を高い生産性の下で製造するこ
とが可能となり、高品質鋼の製造コストを低減しその利
用分野を一層拡大する道を開くなど、産業上極めて有用
な効果がもたらされる。<Summary of Effects> As explained above, according to the present invention, it is possible to produce high-quality steel at high productivity while keeping the amount of slag forming agent used and iron loss to slag low throughout the steelmaking process. This makes it possible to manufacture high-quality steel, and brings about extremely useful effects industrially, such as reducing the manufacturing cost of high-quality steel and paving the way to further expand its fields of use.
第１図は、本発明に係る製鋼法の概要を示した概略説明
図である。
第２図は、“２基の上下両吹き複合吹錬転炉を使用した
脱燐スラグ−メタルの向流的２段階接触精錬を伴う製鋼
方法”の説明図である。
第３図は、溶銑［Ｓｉ］濃度と鉄分ロス少なく所望脱燐
を行うために必要な蛍石投入量との関係を示したグラフ
である。
第４図は、Ｃａ Ｆ ｚ−２Ｃａ Ｏ−３ｉ Ｏｚ系フ
ラッカスの状態図である。
第５図は、ＣａＯ−Ａｌ１ｚＯ：＋系フラックスの状態
図である。
図面において、
１・・・脱燐炉、 ２・・・脱炭炉。
３・・・溶銑、 ４・・・転炉滓。
４′・・・転炉滓を主成分とする脱燐スラグ。
５・・・撹拌ガス吹込みノズル、 ６・・・ランス。
第
１
図
〈＝＝：’：：：ｌ：：：：Ｅヨロ＝＝＝＝＝＝＝＝＝
＝＝＝＝＝＝＝＝ＥＥＥＥロー−・・−一一＝ン第
２図
第３
図
溶銑中のＳｉ含有量（！量％）FIG. 1 is a schematic explanatory diagram showing an outline of the steel manufacturing method according to the present invention. FIG. 2 is an explanatory diagram of the "steel manufacturing method involving countercurrent two-stage catalytic refining of dephosphorized slag-metal using two upper and lower double blowing combined blowing converters". FIG. 3 is a graph showing the relationship between the hot metal [Si] concentration and the amount of fluorite input necessary to perform the desired dephosphorization with less iron loss. FIG. 4 is a state diagram of Ca F z-2Ca O-3i Oz-based flux. FIG. 5 is a state diagram of CaO-Al1zO:+ system flux. In the drawings: 1... Dephosphorization furnace, 2... Decarburization furnace. 3... Hot metal, 4... Converter slag. 4'...Dephosphorization slag whose main component is converter slag. 5... Stirring gas blowing nozzle, 6... Lance. Figure 1〈==:':::l::::Eyoro=========
========EEEE Low...-11=N Figure 2 Figure 3 Si content in hot metal (!Amount%)
Claims (1)
一方を脱燐炉、他方を脱炭炉とし、前記脱燐炉内へ注入
した溶銑に脱炭炉で発生した転炉滓を主成分とする精錬
剤を添加して脱燐スラグ−メタルの２段階向流接触精錬
を行う製鋼法において、前記転炉滓として脱炭炉中にＡ
ｌ＿２Ｏ＿３含有連続鋳造・造塊滓又はアルミドロス添
加を行って発生したものを使用すると共に、脱燐炉内へ
添加する前記転炉滓を主成分とした精錬剤中に蛍石を含
有させて生成スラグ中の〔ＣａＦ＿２＋Ａｌ＿２Ｏ＿３
〕割合を１０〜２０重量％に調整し、かつ底吹きガス撹
拌を行いつつ酸素ガスを上吹きして溶銑温度を１４００
℃以下に保ちながら溶銑脱燐を行い、得られた脱燐溶銑
を脱炭炉に注銑して脱炭並びに仕上脱燐することを特徴
とする、複合吹錬炉を用いた２段向流精錬製鋼法。[Scope of Claims] One of the two converter type furnaces having upper and lower blowing functions is a dephosphorization furnace and the other is a decarburization furnace, and the hot metal injected into the dephosphorization furnace is heated to a decarburization furnace. In a steelmaking method that performs two-step countercurrent catalytic refining of dephosphorized slag-metal by adding a refining agent mainly composed of converter slag generated in
It is produced by using 1_2O_3-containing continuous casting/agglomerate slag or aluminum dross addition, and by incorporating fluorite into the refining agent containing the converter slag as a main component, which is added to the dephosphorization furnace. [CaF_2+Al_2O_3 in slag
] The ratio was adjusted to 10 to 20% by weight, and the temperature of the hot metal was raised to 1400 by blowing oxygen gas upward while stirring the bottom blowing gas.
A two-stage counterflow method using a composite blowing furnace, which is characterized by dephosphorizing hot metal while keeping the temperature below ℃, and pouring the obtained dephosphorized hot metal into a decarburization furnace for decarburization and final dephosphorization. Refining steel manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1260525A JPH0641608B2 (en) | 1989-10-05 | 1989-10-05 | Two-stage countercurrent refining steelmaking process using compound converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1260525A JPH0641608B2 (en) | 1989-10-05 | 1989-10-05 | Two-stage countercurrent refining steelmaking process using compound converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03122210A true JPH03122210A (en) | 1991-05-24 |
| JPH0641608B2 JPH0641608B2 (en) | 1994-06-01 |
Family
ID=17349179
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1260525A Expired - Lifetime JPH0641608B2 (en) | 1989-10-05 | 1989-10-05 | Two-stage countercurrent refining steelmaking process using compound converter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0641608B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5901680A (en) * | 1997-01-17 | 1999-05-11 | Suzuki Motor Corporation | Crank chamber structure for an engine |
| KR100361778B1 (en) * | 1998-12-21 | 2003-01-24 | 주식회사 포스코 | Manufacturing method of ultra low carbon stainless steel by slag control |
-
1989
- 1989-10-05 JP JP1260525A patent/JPH0641608B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5901680A (en) * | 1997-01-17 | 1999-05-11 | Suzuki Motor Corporation | Crank chamber structure for an engine |
| KR100361778B1 (en) * | 1998-12-21 | 2003-01-24 | 주식회사 포스코 | Manufacturing method of ultra low carbon stainless steel by slag control |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0641608B2 (en) | 1994-06-01 |
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