JP2958848B2 - Hot metal dephosphorization method - Google Patents
Hot metal dephosphorization methodInfo
- Publication number
- JP2958848B2 JP2958848B2 JP32908893A JP32908893A JP2958848B2 JP 2958848 B2 JP2958848 B2 JP 2958848B2 JP 32908893 A JP32908893 A JP 32908893A JP 32908893 A JP32908893 A JP 32908893A JP 2958848 B2 JP2958848 B2 JP 2958848B2
- Authority
- JP
- Japan
- Prior art keywords
- slag
- dephosphorization
- converter
- iron oxide
- mno
- 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 - Lifetime
Links
Description
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【産業上の利用分野】本発明は転炉内での溶銑の脱りん
方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dephosphorizing hot metal in a converter.
【０００２】[0002]
【従来の技術】製鋼トータルコストのミニマム化や低り
ん鋼化に関して、従来の溶銑脱りん方法として、（１）
トーピードカー内の溶銑に脱りん用フラックスをインジ
ェクションして予備脱りんを行う方法、（２）取鍋内の
溶銑に脱りん用フラックスをインジェクションもしくは
吹き付けを行い予備脱りんを行う方法、あるいは（３）
２基の転炉を用いて、一方で脱りんを行い、他方で脱炭
を行う方法（例えば、特開昭６３−１９５２１０号公
報）が用いられている。2. Description of the Related Art With regard to minimization of total cost of steel making and low phosphorus steel, (1)
A method for performing preliminary dephosphorization by injecting a dephosphorizing flux into the hot metal in a torpedo car, (2) A method for performing preliminary dephosphorization by injecting or spraying a hot metal in a ladle with a dephosphorizing flux, or (3)
A method of using two converters and performing dephosphorization on one side and decarburization on the other side (for example, JP-A-63-195210) is used.
【０００３】しかしながら、上記（１）、（２）、
（３）のいずれの方法も脱りん工程から脱炭工程に移る
際、溶銑の移し替えを必要とし、温度低下を余儀なくさ
れ、エネルギーロスが大きいという欠点がある。この問
題点を解決するために、特開平２−１８１９８９号公報
において、従来の多工程にわたる精錬機能を転炉に集約
し、溶銑のもつエネルギーロスを大幅に低減すると共
に、転炉前後工程の固定費（設備費、労務費）の大幅な
軽減を可能とする方法が提案されている。However, the above (1), (2),
Any of the methods (3) has a drawback that when transferring from the dephosphorization step to the decarburization step, the hot metal needs to be transferred, the temperature must be reduced, and the energy loss is large. In order to solve this problem, Japanese Patent Application Laid-Open No. Hei 18-181989 discloses that a conventional multi-step refining function is integrated into a converter to greatly reduce the energy loss of hot metal and to fix steps before and after the converter. There have been proposed methods that can significantly reduce costs (equipment costs and labor costs).
【０００４】図２はこのフローを示しているが、第一工
程として溶銑を転炉に装入し、第二工程としてフラック
ス添加と酸素吹込みを行って脱りん精錬を施し、所定の
りん含有量まで低減させ、第三工程として前記転炉を傾
動して第二工程で生成したスラグを排出し、その後第四
工程として同一転炉にてフラックス添加と酸素吹錬によ
り、所定のＣ含有量まで脱炭を行い、第五工程として第
四工程で生成したスラグを該転炉内に残したまま出鋼し
て、再び第一工程へ戻り、前記第五工程までを繰り返し
実施する。FIG. 2 shows this flow. In a first step, molten iron is charged into a converter, and in a second step, dephosphorization and refining are carried out by adding a flux and blowing oxygen to obtain a predetermined phosphorus content. As a third step, the converter is tilted to discharge the slag generated in the second step, and then, as a fourth step, a predetermined C content is obtained by adding flux and oxygen blowing in the same converter. As the fifth step, the slag produced in the fourth step as the fifth step is tapped while leaving it in the converter, the process returns to the first step, and the steps up to the fifth step are repeatedly performed.
【０００５】[0005]
【発明が解決しようとする課題】上述の同一転炉を用い
て脱りん、脱炭工程を続けて行うプロセスを用いると、
脱りん工程から脱炭工程へ移る際のエネルギーロスを少
なくすることができ、この熱裕度拡大分は、第四工程に
おいてＭｎ鉱石の多量還元に用いることができる。If the above-described process of continuously performing the dephosphorization and decarburization steps using the same converter is used,
Energy loss at the time of shifting from the dephosphorization step to the decarburization step can be reduced, and the increased heat allowance can be used for the large reduction of Mn ore in the fourth step.
【０００６】ところが、第四工程で生成したスラグを第
一工程で使用するため、第四工程で生成したスラグ中の
酸化鉄、ＭｎＯ濃度が高いと、脱りん反応が阻害される
という問題点があった。本発明は脱りん工程でのスラグ
組成の適正化を図り、脱りん反応の促進を図る方法を提
供することを目的とするものである。However, since the slag generated in the fourth step is used in the first step, there is a problem that if the concentration of iron oxide and MnO in the slag generated in the fourth step is high, the dephosphorization reaction is inhibited. there were. An object of the present invention is to provide a method for optimizing a slag composition in a dephosphorization step and promoting a dephosphorization reaction.
【０００７】[0007]
【課題を解決するための手段】本発明は、溶銑を精錬し
て溶鋼を製造する際に、第一工程として溶銑を転炉に装
入し、第二工程としてフラックス添加と酸素吹込みを行
って脱りん精錬を施し、所定のりん含有量まで低減さ
せ、第三工程として前記転炉を傾動して第二工程で生成
したスラグを排出し、その後第四工程として同一転炉に
てフラックス添加と酸素吹錬により、所定のＣ含有量ま
で脱炭を行い、第五工程として第四工程で生成したスラ
グを該転炉内に残したまま出鋼して、再び第一工程へ戻
り、前記第五工程までを繰り返し実施する溶鋼製造法の
第二工程において、スラグ中のＣａＯ／ＳｉＯ2 を２．
５以下、且つ酸化鉄とマンガン酸化物濃度の和（Ｔ．Ｆ
ｅ＋ＭｎＯ）を、１５％≦（Ｔ．Ｆｅ＋ＭｎＯ）≦３５
％とすることを特徴とする溶銑の脱りん方法を要旨とす
るものである。According to the present invention, when refining molten iron to produce molten steel, the molten iron is charged into a converter as a first step, and flux addition and oxygen injection are performed as a second step. Dephosphorization and refining to reduce the phosphorus content to a predetermined level, tilt the converter as the third step to discharge the slag generated in the second step, and then add flux in the same converter as the fourth step By oxygen blowing, decarburization was performed to a predetermined C content, and as a fifth step, the slag generated in the fourth step was left in the converter to remove steel, and returned to the first step again. In the second step of the method for producing molten steel in which the steps up to the fifth step are repeatedly performed, the CaO / SiO 2 in the slag is reduced to 2.
5 or less and the sum of iron oxide and manganese oxide concentrations (TF
e + MnO): 15% ≦ (T.Fe + MnO) ≦ 35
% Of the hot metal is dephosphorized.
【０００８】[0008]
【作用】以下本発明を詳述する。本発明は溶銑予備処理
と脱炭とを集約して同一転炉によって操業される。即
ち、例えば図２に示すように炉底に脱りん、脱炭用フラ
ックスを吹込むための１個ないし複数個の底吹き羽口
と、出鋼孔と対面炉腹にスラグフォーミング用ガス吹込
み羽口を備えた上底吹き転炉に溶銑を装入し、前述の底
吹き羽口より生石灰粉をベースとしたフラックスを窒素
等の不活性ガスを搬送ガスとして吹込み脱りん処理を行
う。The present invention will be described below in detail. In the present invention, hot metal pretreatment and decarburization are integrated and operated by the same converter. That is, for example, as shown in FIG. 2, one or a plurality of bottom-blowing tuyeres for blowing a dephosphorizing and decarburizing flux into the furnace bottom, and a gas-blowing tuyere for slag forming at the tapping hole and the belly facing the furnace. The molten iron is charged into an upper-bottom blow converter provided with the above, and a flux based on quicklime powder is blown from the above-mentioned bottom blow tuyere using an inert gas such as nitrogen as a carrier gas to perform a dephosphorization treatment.
【０００９】この時、酸化鉄粉を生石灰粉に混合する
か、あるいは羽口を３重管構造とし、酸素ガスを同一羽
口を通して吹込むことにより、脱りん反応速度を高める
ことができる。もしくは、上吹きランスから酸素ガスを
吹付け、上方よりフラックスを投入、吹込み、吹付け等
の方法で添加して、生成スラグの酸化鉄濃度をコントロ
ールすることによっても、脱りんを促進することができ
る。At this time, the dephosphorization reaction rate can be increased by mixing iron oxide powder with quick lime powder or by forming a tuyere with a triple tube structure and blowing oxygen gas through the same tuyere. Alternatively, dephosphorization is promoted by blowing oxygen gas from the top blowing lance and adding flux from above by blowing, blowing, or spraying to control the iron oxide concentration of the generated slag. Can be.
【００１０】所定のりん含有量まで低下した時点で炉を
反出鋼側（排滓側）に傾動しスラグのみを排出させる。
排滓終了と共に直ちに炉を正立させ、副原料（耐火物保
護、復りん防止用生石灰、ドロマイト、鉄鉱石、Ｍｎ鉱
石等）を投入して通常の上底吹き脱炭精錬を行う。吹止
後、溶鋼は出鋼するが、スラグはそのまま炉内に残し、
次のチャージの脱りん用フラックスとして活用する。At the time when the phosphorus content has decreased to a predetermined phosphorus content, the furnace is tilted to the counter-steel side (discharge side) to discharge only slag.
Immediately after the waste is finished, the furnace is erected immediately, and auxiliary raw materials (quicklime, dolomite, iron ore, Mn ore, etc.) for refractory protection and phosphorus recovery prevention are charged, and ordinary top-bottom blowing decarburization refining is performed. After blowing, the molten steel is tapped, but the slag remains in the furnace,
Use it as a dephosphorization flux for the next charge.
【００１１】ところで、同一転炉で脱りん、脱炭工程を
続けて行うと、脱りん工程から脱炭工程へ移る際のエネ
ルギーロスを少なくすることができ、脱炭工程において
多量のＭｎ鉱石を添加して還元を行い、合金鉄コストの
削減が可能となる。しかしながら、特に多量のＭｎ鉱石
を使用した場合には、生成したスラグ中のマンガン酸化
物濃度が高くなり、そのスラグを脱りん工程でリサイク
ルするために、脱りん反応が阻害されるという問題点が
生じ、Ｍｎ鉱石の添加量を低減せざるを得ないという問
題が発生した。By the way, if the dephosphorization and decarburization steps are continuously performed in the same converter, energy loss at the time of shifting from the dephosphorization step to the decarburization step can be reduced, and a large amount of Mn ore is removed in the decarburization step. By adding and reducing, ferroalloy cost can be reduced. However, particularly when a large amount of Mn ore is used, the manganese oxide concentration in the generated slag increases, and the slag is recycled in the dephosphorization step, so that the dephosphorization reaction is hindered. This caused a problem that the amount of Mn ore added had to be reduced.
【００１２】そこで本発明者らは、脱りん反応に及ぼす
スラグ組成の影響を詳細に調査した結果、Ｍｎ鉱石を多
量添加して脱りん反応が低下する場合は、酸化鉄濃度が
高く、酸化鉄濃度とマンガン酸化物濃度の和が３５％を
超える場合であることを見出した。また（Ｔ．Ｆｅ＋Ｍ
ｎＯ）が１５％より少ない場合にも脱りん反応が進行し
ないことがわかり、脱りん反応を効率よく促進するに
は、スラグ中のＣａＯ／ＳｉＯ2 が２．５以下の条件で
は、酸化鉄とマンガン酸化物濃度の和（Ｔ．Ｆｅ＋Ｍｎ
Ｏ）を、１５％≦（Ｔ．Ｆｅ＋ＭｎＯ）≦３５％になる
ように制御することが必要であることを見出した。これ
は、酸化鉄およびマンガン酸化物はともに溶銑中のりん
を酸化し、溶銑からスラグ中に除去する作用があるた
め、脱りん反応を促進するにはスラグ中の酸化鉄とマン
ガン酸化物濃度の和を少なくとも１５％以上にする必要
があり、またスラグ中の酸化鉄とマンガン酸化物濃度の
和が３５％を超えると、スラグ中に移行したりんを安定
化するのに必要なＣａＯ濃度が減少し、脱りん反応が阻
害されるためである。The present inventors have investigated the effect of slag composition on the dephosphorization reaction in detail. As a result, when a large amount of Mn ore is added to reduce the dephosphorization reaction, the iron oxide concentration is high and the iron oxide concentration is high. It was found that the sum of the concentration and the manganese oxide concentration exceeded 35%. Also, (T.Fe + M
It can be seen that the dephosphorization reaction does not proceed even when nO) is less than 15%. In order to efficiently promote the dephosphorization reaction, iron oxide and iron oxide are used under the condition that CaO / SiO 2 in the slag is 2.5 or less. Sum of manganese oxide concentration (T. Fe + Mn
O) was found to be required to be controlled so that 15% ≦ (T.Fe + MnO) ≦ 35%. This is because both iron oxide and manganese oxide oxidize phosphorus in the hot metal and remove it from the hot metal into the slag. The sum must be at least 15% or more, and if the sum of iron oxide and manganese oxide concentrations in the slag exceeds 35%, the CaO concentration required to stabilize the phosphorus transferred into the slag decreases. However, this is because the dephosphorization reaction is inhibited.
【００１３】すなわち、スラグ中酸化鉄濃度が低い場合
には、マンガン酸化物は酸化鉄の代替として溶銑中のり
んを酸化する作用を有するため、脱りん反応を阻害せ
ず、（Ｔ．Ｆｅ＋ＭｎＯ）≦３５％の範囲では、逆に脱
りん反応を促進する作用があるため、マンガン酸化物濃
度が高くても良い。しかし、スラグ中酸化鉄濃度が高い
場合には、マンガン酸化物濃度が低くても（Ｔ．Ｆｅ＋
ＭｎＯ）＞３５％となってしまい、脱りん反応が阻害さ
れてしまう。That is, when the iron oxide concentration in the slag is low, the manganese oxide has an action of oxidizing phosphorus in the hot metal as a substitute for iron oxide, and therefore does not inhibit the dephosphorization reaction, and (T.Fe + MnO) In the range of ≦ 35%, on the contrary, there is an effect of accelerating the dephosphorization reaction, so that the manganese oxide concentration may be high. However, when the iron oxide concentration in the slag is high, even if the manganese oxide concentration is low (T.Fe +
MnO)> 35%, deteriorating the dephosphorization reaction.
【００１４】以上のことからスラグ中のマンガン酸化物
濃度にあわせてスラグ中酸化物濃度を制御することによ
り、脱りん反応を効率よく進行させることが可能となる
ことが分かる。脱りん工程でのスラグ中の酸化鉄とマン
ガン酸化物濃度の制御は、具体的には例えば以下に示す
方法により行う。脱炭工程でのＭｎ鉱石使用量および吹
止め時の溶鋼の炭素濃度および温度をもとに、脱炭スラ
グ中に残存したＭｎ酸化物量を算出し、脱りん工程にて
酸化鉄等を含むフラックス量および上吹きランスからの
酸素ガス供給速度を調整することによりスラグ中の酸化
鉄濃度を制御し、酸化鉄とマンガン酸化物濃度の和
（Ｔ．Ｆｅ＋ＭｎＯ）を、１５％≦（Ｔ．Ｆｅ＋Ｍｎ
Ｏ）≦３５％とする。From the above, it can be seen that by controlling the oxide concentration in the slag according to the manganese oxide concentration in the slag, the dephosphorization reaction can proceed efficiently. The iron oxide and manganese oxide concentrations in the slag in the dephosphorization step are specifically controlled, for example, by the following method. The amount of Mn oxide remaining in the decarburized slag is calculated based on the amount of Mn ore used in the decarburization process and the carbon concentration and temperature of the molten steel at the time of blowing, and the flux containing iron oxide etc. in the dephosphorization process The iron oxide concentration in the slag is controlled by adjusting the amount and the oxygen gas supply rate from the top blowing lance, and the sum of the iron oxide and manganese oxide concentrations (T.Fe + MnO) is calculated as 15% ≦ (T.Fe + Mn).
O) ≦ 35%.
【００１５】これにより、脱りん工程では脱りん反応を
促進しつつ、かつ脱炭工程では多量のＭｎ鉱石を添加し
て還元を行うことができ、合金鉄コストの削減が可能と
なる。[0015] This makes it possible to promote the dephosphorization reaction in the dephosphorization step and to reduce the amount of Mn ore by adding a large amount of Mn ore in the decarburization step, thereby reducing the cost of ferroalloys.
【００１６】[0016]
【実施例】４．５％のＣ、０．１％のＰ、０．３％のＳ
ｉを含む１３５０℃の溶銑を３００ｔ転炉に装入し、底
吹攪拌を行いながら、スラグのＣａＯ／ＳｉＯ2 が１．
５になるように生石灰をまた脱りん剤として鉄鉱石を添
加し、上吹き吹酸を行い脱りん処理を行った。その後、
生成スラグの７０％を排出し、生石灰とＭｎ鉱石を添加
し脱炭処理を行い、脱炭スラグを転炉内に残したまま出
鋼した。その後、再び上記成分の溶銑を転炉に装入し、
繰り返し脱りん処理と脱炭処理を行った。EXAMPLE 4.5% C, 0.1% P, 0.3% S
The molten iron containing 1350 ° C. was charged into a 300-t converter and the slag CaO / SiO 2 was 1.
Iron lime was added as a dephosphorizing agent using quick lime so as to obtain a dephosphorizing agent, and dephosphorizing treatment was performed by performing top-blowing acid. afterwards,
70% of the generated slag was discharged, quick lime and Mn ore were added to perform decarburization treatment, and tapping was performed with the decarburized slag remaining in the converter. After that, the hot metal of the above components is charged again into the converter,
Dephosphorization and decarburization were repeated.
【００１７】脱炭工程で添加するＭｎ鉱石量は、製造す
る鋼種により５〜３０ｋｇ／ｔの範囲で添加した。そし
て脱炭工程でのＭｎ鉱石使用量および吹止め時の溶鋼の
炭素濃度および温度をもとに、脱炭スラグ中に残存した
Ｍｎ酸化物量を算出し、脱りん工程にて鉄鉱石を含むフ
ラックス量および上吹きランスからの酸素ガス供給速度
および上吹きランス高さを調整することによりスラグ中
の酸化鉄濃度を制御し、酸化鉄とマンガン酸化物濃度の
和（Ｔ．Ｆｅ＋ＭｎＯ）を、１５％≦（Ｔ．Ｆｅ＋Ｍｎ
Ｏ）≦３５％とした。また、比較として上記範囲から外
れる条件での操業も実施した。The amount of Mn ore added in the decarburization step is in the range of 5 to 30 kg / t depending on the type of steel to be produced. Then, the amount of Mn oxide remaining in the decarburized slag is calculated based on the amount of Mn ore used in the decarburization step and the carbon concentration and temperature of the molten steel at the time of blowing, and the flux containing iron ore in the dephosphorization step. The iron oxide concentration in the slag is controlled by adjusting the amount and the oxygen gas supply rate from the top blowing lance and the height of the top blowing lance, and the sum of iron oxide and manganese oxide (T.Fe + MnO) is reduced by 15%. ≤ (T.Fe + Mn
O) ≦ 35%. In addition, as a comparison, an operation was performed under conditions outside the above range.
【００１８】図１に脱りん期の脱りん率とその時のスラ
グ中の酸化鉄とマンガン酸化物濃度の和との関係を示
す。スラグ中酸化鉄とマンガン酸化物濃度の和を１５％
≦（Ｔ．Ｆｅ＋ＭｎＯ）≦３５％に制御する操業を行っ
た場合には、安定して脱りん率が８０％以上であるのに
対し、（Ｔ．Ｆｅ＋ＭｎＯ）＜１５％の場合および
（Ｔ．Ｆｅ＋ＭｎＯ）＞３５％の場合には、脱りん率が
極端に悪くなっていることがわかる。また酸化鉄とマン
ガン酸化物濃度の和（Ｔ．Ｆｅ＋ＭｎＯ）が１５％≦
（Ｔ．Ｆｅ＋ＭｎＯ）≦３５％から外れる操業を行った
場合、製品の所定のりん濃度を達成するために生石灰量
を増加する必要があり、生石灰原単位は５〜１０ｋｇ／
ｔ増加し、コスト増につながった。FIG. 1 shows the relationship between the dephosphorization rate in the dephosphorization stage and the sum of the iron oxide and manganese oxide concentrations in the slag at that time. 15% sum of iron oxide and manganese oxide concentration in slag
≦ (T.Fe + MnO) ≦ 35%, the dephosphorization rate is stably 80% or more, while (T.Fe + MnO) <15%, and (T.Fe + MnO) <15%. It can be seen that when Fe + MnO)> 35%, the dephosphorization rate is extremely poor. The sum of the iron oxide and manganese oxide concentrations (T.Fe + MnO) is 15% ≦
(T. Fe + MnO) When the operation is out of 35%, it is necessary to increase the amount of quicklime to achieve a predetermined phosphorus concentration of the product, and the quicklime basic unit is 5 to 10 kg /.
and the cost increased.
【００１９】また、酸化鉄とマンガン酸化物濃度の和
（Ｔ．Ｆｅ＋ＭｎＯ）を、１５％≦（Ｔ．Ｆｅ＋Ｍｎ
Ｏ）≦３５％とする操業を行うことにより、安定した脱
炭期のマンガン鉱石の多量添加が可能となり、合金鉄の
コスト削減が可能となった。The sum of the iron oxide and manganese oxide concentrations (T.Fe + MnO) is 15% ≦ (T.Fe + MnO).
O) By performing the operation at ≤35%, a large amount of manganese ore in the stable decarburization stage can be added, and the cost of ferroalloys can be reduced.
【００２０】[0020]
【発明の効果】スラグ中のＣａＯ／ＳｉＯ2 を２．５以
下、且つ酸化鉄とマンガン酸化物濃度の和（Ｔ．Ｆｅ＋
ＭｎＯ）を、１５％≦（Ｔ．Ｆｅ＋ＭｎＯ）≦３５％に
なるように制御することにより、脱りん工程では脱りん
反応を促進しつつ、かつ脱炭工程では多量のＭｎ鉱石を
添加して還元を行うことができ、合金鉄コストの削減が
可能となった。According to the present invention, the content of CaO / SiO 2 in slag is 2.5 or less, and the sum of iron oxide and manganese oxide concentrations (T.Fe +
MnO) is controlled so as to satisfy 15% ≦ (T.Fe + MnO) ≦ 35%, thereby promoting the dephosphorization reaction in the dephosphorization step and adding a large amount of Mn ore in the decarburization step. And the cost of ferro-alloys can be reduced.
【図１】脱りん処理後の脱りん率とスラグ中の酸化鉄と
マンガン酸化物濃度の和との関係を示す図である。FIG. 1 is a graph showing a relationship between a dephosphorization rate after a dephosphorization treatment and a sum of iron oxide and manganese oxide concentrations in slag.
【図２】同一転炉による精錬プロセスの模式的説明図で
ある。FIG. 2 is a schematic explanatory view of a refining process using the same converter.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 升光 法行 北海道室蘭市仲町12番地 新日本製鐵株 式会社室蘭製鐵所内 (72)発明者 小泉 文夫 北海道室蘭市仲町12番地 新日本製鐵株 式会社室蘭製鐵所内 (56)参考文献 特開 平５−247511（ＪＰ，Ａ) 特開 平２−250913（ＪＰ，Ａ) 特公 平４−80087（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.6，ＤＢ名) C21C 5/28 C21C 1/02 110 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Noriyuki Shomitsu 12 Nakamachi, Muroran, Hokkaido Nippon Steel Corporation Muroran Works (72) Inventor Fumio Koizumi 12 Nakamachi, Muroran, Hokkaido Nippon Steel (56) References JP-A-5-247511 (JP, A) JP-A-2-250913 (JP, A) JP 4-80087 (JP, B2) (58) Field (Int.Cl. 6 , DB name) C21C 5/28 C21C 1/02 110
Claims (1)
一工程として溶銑を転炉に装入し、第二工程としてフラ
ックス添加と酸素吹込みを行って脱りん精錬を施し所定
のりん含有量まで低減させ、第三工程として前記転炉を
傾動して第二工程で生成したスラグを排出し、その後第
四工程として同一転炉にて脱炭を行い、第五工程として
第四工程で生成したスラグを該転炉内に残したまま出鋼
して、再び第一工程へ戻り、繰り返し上記工程を行う溶
鋼製造法の第二工程において、スラグ中のＣａＯ／Ｓｉ
Ｏ2 を２．５以下、且つ酸化鉄とマンガン酸化物濃度の
和（Ｔ．Ｆｅ＋ＭｎＯ）を、１５％≦（Ｔ．Ｆｅ＋Ｍｎ
Ｏ）≦３５％とすることを特徴とする溶銑の脱りん方
法。When refining molten iron to produce molten steel, the molten iron is charged into a converter as a first step, and a dephosphorization refining is performed by adding a flux and blowing oxygen as a second step. As a third step, the converter is tilted to discharge the slag generated in the second step, and then the fourth step is decarburized in the same converter, and the fifth step is performed in the fourth step. In the second step of the molten steel production method in which the slag generated in the process is left in the converter and the process returns to the first process, and the above process is repeated, the CaO / Si in the slag is removed.
O 2 is 2.5 or less, and the sum of iron oxide and manganese oxide concentrations (T.Fe + MnO) is 15% ≦ (T.Fe + Mn).
O) A method for dephosphorizing hot metal, wherein ≦ 35%.
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32908893A JP2958848B2 (en) | 1993-12-24 | 1993-12-24 | Hot metal dephosphorization method |
| CN94192953A CN1041843C (en) | 1993-06-30 | 1994-06-30 | Steel manufacturing method using converter |
| DE69423630T DE69423630T2 (en) | 1993-06-30 | 1994-06-30 | STEEL MANUFACTURING IN CONVERTER WITH DEPHOSPHORUS LEVEL |
| BR9406985-9A BR9406985A (en) | 1993-06-30 | 1994-06-30 | Process to produce steel in converter |
| ES94919835T ES2143547T3 (en) | 1993-06-30 | 1994-06-30 | STEEL MANUFACTURING METHOD USING DEPHOSPHORIZATION IN CONVERTER. |
| AU70831/94A AU680268B2 (en) | 1993-06-30 | 1994-06-30 | Steel manufacturing method using converter |
| EP94919835A EP0714989B1 (en) | 1993-06-30 | 1994-06-30 | Steel manufacturing method using converter dephosphorisation |
| CA002166097A CA2166097C (en) | 1993-06-30 | 1994-06-30 | Process for producing steel by converter |
| KR1019950705930A KR0159180B1 (en) | 1993-06-30 | 1994-06-30 | Steel manufacturing method using converter |
| PCT/JP1994/001070 WO1995001458A1 (en) | 1993-06-30 | 1994-06-30 | Steel manufacturing method using converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32908893A JP2958848B2 (en) | 1993-12-24 | 1993-12-24 | Hot metal dephosphorization method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07179921A JPH07179921A (en) | 1995-07-18 |
| JP2958848B2 true JP2958848B2 (en) | 1999-10-06 |
Family
ID=18217484
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32908893A Expired - Lifetime JP2958848B2 (en) | 1993-06-30 | 1993-12-24 | Hot metal dephosphorization method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2958848B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003105419A (en) * | 2001-09-27 | 2003-04-09 | Nippon Steel Corp | Method for pretreating molten iron |
| KR102065059B1 (en) * | 2017-12-26 | 2020-01-10 | 주식회사 포스코 | Method for refining molten steel in cinverter |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100887132B1 (en) * | 2002-08-20 | 2009-03-04 | 주식회사 포스코 | Method for Tapping Molten Steel in Converter |
| KR100749023B1 (en) * | 2006-05-26 | 2007-08-14 | 주식회사 포스코 | Method for refining extra low phosphorous steel in converter |
| JP5233378B2 (en) * | 2008-04-10 | 2013-07-10 | 新日鐵住金株式会社 | Hot phosphorus dephosphorization method |
| JP5691232B2 (en) * | 2010-04-20 | 2015-04-01 | Ｊｆｅスチール株式会社 | Converter refining method |
| JP7151494B2 (en) * | 2018-04-27 | 2022-10-12 | 日本製鉄株式会社 | Method for recycling converter slag |
-
1993
- 1993-12-24 JP JP32908893A patent/JP2958848B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003105419A (en) * | 2001-09-27 | 2003-04-09 | Nippon Steel Corp | Method for pretreating molten iron |
| KR102065059B1 (en) * | 2017-12-26 | 2020-01-10 | 주식회사 포스코 | Method for refining molten steel in cinverter |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07179921A (en) | 1995-07-18 |
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