JP2000256719A - Steelmaking method - Google Patents
Steelmaking methodInfo
- Publication number
- JP2000256719A JP2000256719A JP6175699A JP6175699A JP2000256719A JP 2000256719 A JP2000256719 A JP 2000256719A JP 6175699 A JP6175699 A JP 6175699A JP 6175699 A JP6175699 A JP 6175699A JP 2000256719 A JP2000256719 A JP 2000256719A
- Authority
- JP
- Japan
- Prior art keywords
- converter
- slag
- dephosphorization
- refining
- discharged
- 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.)
- Withdrawn
Links
Classifications
-
- 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
- Y02P10/20—Recycling
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
【0001】[0001]
【発明の属する技術分野】本発明は1基の転炉形式の炉
を利用し、脱りん精錬、出湯、再装入、脱炭精錬を連続
的に行う操業において、脱炭精錬後の転炉スラグ中のC
aO分、鉄、Mn分を効率的に再利用する製鋼方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes a converter type furnace to continuously perform dephosphorization refining, tapping, recharging, and decarburization refining. C in slag
The present invention relates to a steelmaking method for efficiently reusing aO, iron, and Mn.
【0002】[0002]
【従来の技術】近年、鋼材に関する品質要求(特に低り
ん低硫化)が厳しくなる中、低りん鋼をより安価なコス
トで製造するための様々な製鋼方法が提案されている。
特に、熱力学的に脱りんに有利な低温域において、事前
に高効率で溶銑の脱りん処理を行い、その後に脱炭処理
を実施する溶銑予備処理が主流となっており、その中で
近年工程集約による固定費削減の観点から、脱りん処理
を転炉で行う転炉型溶銑予備処理が一般化しつつある。2. Description of the Related Art In recent years, as the quality requirements (particularly low phosphorus and low sulfuration) regarding steel materials have become severe, various steel making methods for producing low phosphorus steel at lower cost have been proposed.
In particular, in the low temperature region where thermodynamics are advantageous for dephosphorization, hot metal pretreatment is performed in which hot metal dephosphorization is performed with high efficiency in advance, and then decarburization is performed. From the viewpoint of reducing fixed costs through process consolidation, converter-type hot metal pretreatment in which dephosphorization is performed in a converter is becoming popular.
【0003】一方、溶銑予備処理における脱りん精錬剤
コスト削減、および、発生スラグ量削減という観点か
ら、溶銑予備処理段階においてはまだ脱りん能を有して
いる転炉スラグの脱りん精錬剤としての再利用が積極的
に行われている。転炉型溶銑予備処理の脱炭スラグの再
利用方法としては、特開昭62−290815号公報に
示されるような、上底吹き機能を有する2基の転炉形式
の炉をそれぞれ脱りん専用炉および脱炭専用炉として利
用し、脱炭処理後の転炉滓を一旦系外に排出し、それを
脱りん精練剤として脱りん炉に装入する方法がある。こ
の方法では、一旦鍋に排出した転炉スラグを再度転炉に
装入することから、 (a)転炉スラグの顕熱ロスが大きく、脱りん反応精錬
において転炉滓の昇温に時間を要するため、結局滓化不
良となって十分な脱りん反応効率が得られない。 (b)熱間で再利用する場合、転炉滓を安全に輸送する
ための容器と、その転炉滓の徐冷や転炉装入容器に入れ
るための破砕等の作業行程が必要であり、その分の作業
時間も必要となる。 (c)脱りん専用炉、脱炭専用炉と転炉を2基必要とす
るため設備的な制約が大きい。という問題がある。On the other hand, from the viewpoint of reducing the cost of the dephosphorizing refining agent in the hot metal pretreatment and reducing the amount of generated slag, the dephosphorizing refining agent for the converter slag still having the dephosphorizing ability in the hot metal pretreatment stage. Is actively being reused. As a method of reusing the decarburized slag in the converter type hot metal pretreatment, two converter type furnaces each having a top-bottom blowing function as shown in JP-A-62-290815 are dedicated to dephosphorization. There is a method in which a converter and a furnace for exclusive use of decarburization are used, and the converter slag after the decarburization treatment is once discharged out of the system, and is charged as a dephosphorizing scouring agent into the dephosphorization furnace. According to this method, the converter slag once discharged into the pan is charged into the converter again. (A) The sensible heat loss of the converter slag is large, and it takes time to raise the temperature of the converter slag in the dephosphorization reaction refining. As a result, slag formation is eventually caused and sufficient dephosphorization reaction efficiency cannot be obtained. (B) In the case of hot reuse, a container for safely transporting the converter slag and a work process such as gradual cooling of the converter slag and crushing for putting it in the converter charging container are required. That time is also required. (C) Since two furnaces, one dedicated to dephosphorization and the other dedicated to decarburization, are required, there are great restrictions on equipment. There is a problem.
【0004】再利用する脱炭スラグの脱りん精錬におけ
る滓化を向上する目的で、特開平5−156338号公
報においては、滓鍋に蛍石を装入した状態で脱炭スラグ
を受滓し、該蛍石を脱炭スラグ中に溶融・混合した後に
再利用する方法が開示されている。しかし、この方法で
も脱炭スラグ中のフッ素濃度が10%未満ではスラグの
融点が高いため滓化不良になると記されている。リサイ
クル時のスラグの温度が低いため、スラグの昇温に時間
を要しているためと推測される。[0004] In order to improve the slagging in the dephosphorization and refining of the decarburized slag to be reused, Japanese Patent Laid-Open Publication No. 5-156338 discloses a method of receiving decarburized slag with fluorite charged in a slag pot. A method is disclosed in which the fluorite is reused after being melted and mixed in the decarburized slag. However, it is described that, even in this method, if the fluorine concentration in the decarburized slag is less than 10%, the slag has a high melting point, resulting in poor slag formation. It is presumed that the temperature of the slag at the time of recycling is low, and it takes time to raise the temperature of the slag.
【0005】[0005]
【発明が解決しようとする課題】上述した問題を解決す
るために、本発明者らは同一炉で脱りん精錬及び脱炭精
錬を行う方式について検討した。高炉から出銑された溶
銑を転炉に装入し、まず脱りん精錬を行い、脱りん精錬
後は、溶湯とスラグを夫々排出し、次に脱りん精錬後の
溶湯を同じ転炉に再装入し、脱炭精錬を行う。脱炭精錬
した後の溶鋼は転炉から排出するが、脱炭スラグは炉内
に残し、次チャージの脱りん吹錬に利用する。この方法
では、脱炭スラグを転炉炉内に残したまま次チャージに
利用できるので、スラグ顕熱ロスも小さく、また、スラ
グ処理設備なども不要である。In order to solve the above-mentioned problems, the present inventors have studied a system for performing dephosphorization refining and decarburization refining in the same furnace. The molten metal from the blast furnace is charged into a converter, and then dephosphorized and refined.After dephosphorization and refining, the molten metal and slag are discharged respectively, and then the molten metal after dephosphorized and refined is returned to the same converter. Charge and decarburize and refine. The molten steel after the decarburization refining is discharged from the converter, but the decarburized slag is left in the furnace and used for dephosphorization blowing of the next charge. In this method, since the decarburized slag can be used for the next charge while remaining in the converter furnace, the slag sensible heat loss is small, and slag treatment equipment is not required.
【0006】脱炭スラグを炉内に残したまま脱りん精錬
に再利用する場合、スラグを溶融状態のまま再利用でき
ると顕熱ロスも少なく、反応性も良いので最も効率的で
ある。しかし、転炉滓を溶融状態で炉内に残すと、次チ
ャージの溶銑装入時に前記転炉滓と溶銑が急激に反応
し、溶銑が転炉から吹き出す可能性がある。そのため、
転炉滓の再利用を行う場合は、炉内に残した転炉滓は次
チャージの溶銑装入時に凝固状態であることが必要であ
る。[0006] When the decarburized slag is reused for dephosphorization refining while remaining in the furnace, it is most efficient if the slag can be reused in a molten state because sensible heat loss is small and reactivity is good. However, if the converter slag is left in the furnace in a molten state, the converter slag and the hot metal react rapidly when the next charge of the hot metal is charged, and the hot metal may blow out from the converter. for that reason,
When reusing converter slag, it is necessary that the converter slag left in the furnace be in a solidified state at the time of charging the hot metal for the next charge.
【0007】この問題を解決するため、転炉滓を石灰石
等の冷却材で凝固させた後、次チャージの溶銑を装入し
て転炉脱りん処理を行うことが考えられる。しかし、こ
の方法ではスロッピングや脱りん石灰効率の低下といっ
た現象が発生し、これを防止するための石灰分の使用増
が必要となり、転炉滓の再利用による脱りん精錬剤削減
効果を十分に享受することができないという問題があっ
た。In order to solve this problem, it is conceivable to solidify the converter slag with a coolant such as limestone and then charge the hot metal of the next charge to perform the converter dephosphorization. However, in this method, phenomena such as slopping and a decrease in dephosphorized lime efficiency occur, and it is necessary to increase the use of lime to prevent such a phenomenon. There was a problem that it could not be enjoyed.
【0008】本発明の第1の目的は、同一転炉にて脱り
ん処理、出湯、再装入、脱炭処理を連続的に行う製鋼方
法において、脱炭処理後の転炉滓を転炉々内に残し次チ
ャージの転炉脱りん処理に効率良く再利用できる製鋼法
を提供するものである。A first object of the present invention is to provide a steelmaking method in which dephosphorization, tapping, recharging, and decarburization are continuously performed in the same converter. An object of the present invention is to provide a steelmaking method that can be efficiently reused in a converter dephosphorization treatment of a next charge, which is left inside.
【0009】溶銑中Mnは脱炭精錬中に燃焼して酸化
し、脱炭スラグ中に移動する。このMnの酸化を抑制し
て脱炭精錬におけるMn歩留を向上できれば、合金とし
てのMn添加量を削減することができる。Mn in the hot metal is burned and oxidized during the decarburization refining and moves into the decarburized slag. If the oxidation of Mn can be suppressed to improve the Mn yield in decarburization refining, the amount of Mn added as an alloy can be reduced.
【0010】本発明の第2の目的は、同一転炉にて脱り
ん処理、出湯、再装入、脱炭処理を連続的に行う製鋼方
法において、脱炭処理後のMn歩留の高い製鋼法を提供
するものである。A second object of the present invention is to provide a steelmaking method in which dephosphorization, tapping, recharging, and decarburization are continuously performed in the same converter, wherein the steelmaking with a high Mn yield after decarburization is performed. It provides the law.
【0011】[0011]
【課題を解決するための手段】即ち、本発明の要旨とす
るところは、第1に、転炉において、まず、最初に主に
脱りん精錬を行い、その後転炉内溶湯を受湯鍋に排出
し、ついで溶湯排出後転炉内の脱りんスラグを排滓鍋に
排出し、前記受湯鍋に排出した溶湯を再度前記転炉に装
入し、主に脱炭精錬を行い、脱炭後溶鋼を排出した後、
脱炭スラグを転炉内に残し、該残留した脱炭スラグに蛍
石、Al灰、ボロン酸化物の内の一種以上を含む副材を
投入し、次チャージの脱りん精錬に使用することを特徴
とする製鋼方法である。That is, the gist of the present invention is as follows. First, in a converter, first, dephosphorization is mainly performed first, and then the molten metal in the converter is discharged to a receiving pan. Then, after the molten metal is discharged, the dephosphorized slag in the converter is discharged into a waste pan, the molten metal discharged into the receiving pan is charged into the converter again, mainly decarburization refining, and after decarburization, After discharging
The decarburized slag is left in the converter, and the remaining decarburized slag is charged with an auxiliary material containing at least one of fluorite, Al ash, and boron oxide, and is used for dephosphorization refining of the next charge. This is a characteristic steelmaking method.
【0012】本発明者らは、上記第1の目的を達成すべ
く種々の試験研究を行った。その結果、脱炭スラグを炉
内に残したまま脱りん精錬に再利用するに際してのスロ
ッピングや脱りん石灰効率の低下は、脱りん精錬におけ
るスラグの滓化不足によるものであることが判明した。
即ち、脱炭処理後の転炉滓の融点は1600〜1700
℃と高く、またこのような組成のスラグにさらに石灰石
等を添加して温度を低下させるため、凝固後のスラグは
気泡率の低い緻密な状態となっており、溶湯温度が13
00℃程度の脱りん精錬中には十分に溶解しない。The present inventors have conducted various tests and researches to achieve the first object. As a result, it was found that the slopping and the decrease in dephosphorized lime efficiency when the decarburized slag was reused for dephosphorization while remaining in the furnace were due to insufficient slag slag formation in dephosphorization and refining. .
That is, the melting point of the converter slag after the decarburization treatment is 1600 to 1700.
° C, and slag having such a composition is further added with limestone or the like to lower the temperature. Therefore, the slag after solidification is in a dense state with a low bubble rate, and the molten metal temperature is 13 ° C.
It does not dissolve sufficiently during dephosphorization refining at about 00 ° C.
【0013】本発明者らの研究結果によると、再利用す
る転炉滓の滓化率を向上することにより、スロッピング
防止および、脱りん石灰効率の向上が可能となる。そし
て、そのためには、蛍石、Al灰、ボロン酸化物をスラ
グ中に添加するのが効果的であるということを知見し
た。According to the research results of the present inventors, it is possible to prevent slopping and improve the efficiency of dephosphorized lime by improving the slag conversion rate of the converter slag to be reused. And for that purpose, it was found that it is effective to add fluorite, Al ash, and boron oxide to the slag.
【0014】本発明者らの試験研究においては、転炉滓
中のフッ素濃度が5%程度でも滓化は良好であった。本
発明では転炉滓を排出せず転炉炉内に残留させた状態で
再利用することにより、転炉滓は凝固状態ではあるが、
高温で次チャージの転炉脱りん処理に供することが可能
となるため、転炉滓を短時間で昇熱できる。即ち、投入
する蛍石の量が少なくても効果を発揮できるのである。
前述の特開平5−156338号公報に開示された発明
において、フッ素濃度が10%未満で滓化不良となる理
由は、転炉滓を一旦炉外に排出して冷却するため転炉滓
の温度が下がり、脱りん処理に供された際、転炉滓の昇
熱に時間を要しているためと推測される。In the test and research conducted by the present inventors, slagification was satisfactory even when the fluorine concentration in the converter slag was about 5%. In the present invention, the converter slag is in a solidified state by reusing the converter slag without discharging and remaining in the converter furnace,
Since the converter can be subjected to the dephosphorization treatment of the next charge at a high temperature, the converter slag can be heated in a short time. That is, the effect can be exhibited even if the amount of the fluorite to be introduced is small.
In the invention disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-156338, the reason why the slagging failure occurs when the fluorine concentration is less than 10% is that the converter slag is once discharged out of the furnace and cooled, so that the temperature of the converter slag is reduced. It is presumed that, when subjected to the dephosphorization treatment, it took time to heat the converter slag.
【0015】また、蛍石と同様の効果を、Al灰、ある
いはボロン酸化物を投入することによっても得られる。The same effect as fluorite can also be obtained by adding Al ash or boron oxide.
【0016】本発明の要旨とするところは、第2に、転
炉において、まず、最初に主に脱りん精錬を行い、その
後転炉内溶湯を受湯鍋に排出し、次いで溶湯排出後、転
炉内の脱りんスラグを排滓鍋に排出し、前記受湯鍋に排
出した溶湯を再度前記転炉に装入し、主に脱炭精錬を行
い、該脱炭精錬の末期に蛍石、Al灰、ボロン酸化物の
内の一種以上を含む副材を投入し、脱炭後溶鋼を排出し
た後、脱炭スラグを転炉内に残し、次チャージの脱りん
精錬に使用することを特徴とする製鋼方法である。The gist of the present invention is that, secondly, in the converter, first, dephosphorization and refining are first performed, and then the molten metal in the converter is discharged to a receiving pan, and then the molten metal is discharged. The dephosphorized slag in the furnace is discharged to a waste pan, and the molten metal discharged to the receiving pan is charged into the converter again, mainly performing decarburization refining, and at the end of the decarburization refining, fluorite, Al It is characterized by adding auxiliary materials containing at least one of ash and boron oxide, discharging the molten steel after decarburization, leaving the decarburized slag in the converter, and using it for dephosphorization refining of the next charge. Steelmaking method.
【0017】前記第1の目的に加え、溶鋼[Mn]を向
上させるという第2の目的を達成するためには、上記の
とおり、脱炭吹錬末期に上記蛍石、Al灰、ボロン酸化
物の内、一種以上を含む副材を投入する。投入した副材
のうち、蛍石、Al灰は、転炉スラグ中鉄酸化物および
Mn酸化物を還元させることによりMn歩留まりの向上
を図ることで実現することができる。さらにこの第2の
発明においては、吹錬末期に投入した副材が転炉スラグ
中に含有されるため、引き続き行われる次チャージの転
炉脱りん処理においてリサイクルスラグを短時間に速や
かに溶解し、脱りん効率を改善することが可能であり、
第1の目的を同時に達成することができる。In order to achieve the second object of improving the molten steel [Mn] in addition to the first object, as described above, at the end of decarburization blowing, the fluorite, Al ash, and boron oxide are used. Among them, the auxiliary materials including one or more types are introduced. Of the added auxiliary materials, fluorite and Al ash can be realized by reducing the iron oxide and the Mn oxide in the converter slag to improve the Mn yield. Furthermore, in the second invention, since the auxiliary material charged in the last stage of the blowing is contained in the converter slag, the recycled slag is quickly melted in a short time in the subsequent converter dephosphorization treatment of the next charge. , It is possible to improve the dephosphorization efficiency,
The first object can be achieved at the same time.
【0018】[0018]
【発明の実施の形態】この発明においては、脱炭吹錬終
了後、転炉内残留スラグに蛍石、Al灰、ボロン酸化物
の内、一種以上を含む副材を投入することにより、脱炭
滓を低融点化し、次チャージの脱りん処理時におけるリ
サイクルスラグの滓化率を向上させることができる。し
たがって、脱りん石灰効率を向上させることができる。
また、特に、蛍石に含有されるCaF2には、スラグ中
のMn酸化物の濃度を低下させる効果があることから、
脱炭吹錬末期に蛍石を投入することにより、スラグ中の
Mn酸化物を還元させ、歩留を向上させることも可能で
ある。DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, after decarburization blowing is completed, auxiliary materials containing at least one of fluorite, Al ash, and boron oxide are added to the residual slag in the converter to remove the decarburized slag. It is possible to lower the melting point of the coal slag and improve the slag conversion rate of the recycled slag during the dephosphorization treatment of the next charge. Therefore, the dephosphorization lime efficiency can be improved.
Particularly, since CaF 2 contained in fluorite has an effect of reducing the concentration of Mn oxide in slag,
By introducing fluorite at the end of decarburization blowing, it is possible to reduce the Mn oxide in the slag and improve the yield.
【0019】蛍石の投入量を増加させれば、脱りん温度
域におけるリサイクルスラグの液相率は向上し、脱りん
吹錬時の滓化率向上には有効であるが、蛍石の多量使用
は転炉耐火物に悪影響を及ぼすため、蛍石の投入量は吹
錬条件に応じて必要最小量にとどめるのが望ましい。If the amount of fluorite is increased, the liquid phase ratio of the recycled slag in the dephosphorization temperature range is improved, which is effective for improving the slagging ratio during dephosphorization blowing. Since the use has a bad effect on the converter refractory, it is desirable that the input amount of the fluorite be kept to a minimum necessary amount according to the blowing conditions.
【0020】なお、滓化率向上という点ではAl灰、ボ
ロン酸化物でも蛍石と同様の効果が期待できることか
ら、蛍石の代わりにAl灰、ボロン酸化物の滓化剤を使
用してもよい。アルミ灰中の主成分Al2O3あるいはボ
ロン酸化物ともに、転炉スラグに添加することによりそ
の融点を低下させることができるからである。Since the same effect as fluorite can be expected with Al ash and boron oxide in terms of improving the slagging rate, a slagging agent of Al ash and boron oxide can be used instead of fluorite. Good. This is because the melting point of the main component Al 2 O 3 or boron oxide in the aluminum ash can be reduced by adding it to the converter slag.
【0021】蛍石の添加量は炉内残留スラグ量の5%程
度とすることが好ましい。添加量があまりにも少ないと
滓化に寄与せず、逆に多すぎると耐火物を溶損すること
となる。Al灰の添加量は炉内残留スラグ量の10%程
度とする。少ないと滓化に寄与せず、多すぎると脱P能
に影響を及ぼすからである。The amount of fluorite added is preferably about 5% of the amount of residual slag in the furnace. If the addition amount is too small, it does not contribute to slagging, and if it is too large, the refractory will be eroded. The amount of Al ash added is about 10% of the amount of residual slag in the furnace. If the amount is too small, it does not contribute to slagging, and if the amount is too large, it has an effect on the P removal ability.
【0022】[0022]
【実施例】以下、本発明の詳細を実施例に基づいて説明
する。図1は本発明法に係わる転炉精錬プロセスを示し
たものである。1は転炉であり、高炉から出銑された溶
銑は、必要に応じて脱硫処理が行われた後、前記転炉1
において脱りん処理がなされる。前記脱りん処理におい
ては、精錬剤として後述の本発明に係わるリサイクルス
ラグを使用し、また、必要に応じて生石灰、蛍石、鉄鉱
石等の媒溶剤が投入され、脱りん処理が行われる。DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on embodiments. FIG. 1 shows a converter refining process according to the present invention. Reference numeral 1 denotes a converter, and the hot metal that has been tapped from the blast furnace is subjected to desulfurization treatment as required, and then the converter 1
Is subjected to a dephosphorization treatment. In the dephosphorization treatment, a recycled slag according to the present invention, which will be described later, is used as a refining agent, and a medium solvent such as quicklime, fluorite, iron ore, or the like is added as needed to perform the dephosphorization treatment.
【0023】前記脱りん処理を終えた溶銑は、2の受湯
鍋に排出され、転炉脱りん滓が3の排滓鍋に排出された
後、再び前記転炉1に装入され脱炭処理が行われる。脱
炭処理に際しては、必要に応じて、生石灰、石灰石、ド
ロマイト、Mn鉱石、鉄鉱石等の媒溶剤が投入され、目
的に応じた成分範囲となるまで脱炭処理が行われる。After the dephosphorization treatment, the hot metal is discharged to a hot-water receiving pan No. 2 and the converter dephosphorization slag is discharged to a discharge pan No. 3 and then charged again into the converter 1 to be decarbonized. Is performed. At the time of the decarburization treatment, a medium solvent such as quick lime, limestone, dolomite, Mn ore, iron ore, or the like is added as necessary, and the decarburization treatment is performed until the component range according to the purpose is reached.
【0024】図1に示す操業を実施した例について以下
に説明する。An example in which the operation shown in FIG. 1 is performed will be described below.
【0025】[実施例1]250tの上底吹転炉におい
て、脱炭処理終了後、溶鋼を排出した後、炉内にスラグ
8を残留させ、CaF2が炉内残留スラグの10%程度
となるように蛍石を投入し、その後、スラグを凝固させ
るための冷却材を投入した本発明の場合、スラグを凝固
させるための冷却材のみを投入した比較例の場合のそれ
ぞれについて、脱りん精錬後のスラグ分析を実施し、滓
化率と脱りん石灰効率を求めた。プロセスフローの概略
を図1に示し、その結果を表1に示す。なお、脱りん精
錬条件等については表1に示す値とした。また、滓化率
と脱りん石灰効率はそれぞれ以下の式にて算出する。 滓化率 = 脱りん後スラグ実績塩基度/脱りん後スラ
グ計算塩基度 脱りん石灰効率 = 脱りん後スラグ中りん濃度/脱り
ん後スラグ中石灰濃度[Example 1] In a 250-ton top-bottom blow converter, after the decarburization treatment was completed, molten steel was discharged, and slag 8 was left in the furnace. CaF 2 was reduced to about 10% of the remaining slag in the furnace. In the case of the present invention in which fluorite was charged, and then a coolant for solidifying the slag was added, in the case of the comparative example in which only the coolant for solidifying the slag was added, for each of the comparative examples, The subsequent slag analysis was performed to determine the slag conversion rate and the dephosphorization lime efficiency. An outline of the process flow is shown in FIG. 1, and the results are shown in Table 1. The dephosphorization refining conditions and the like were the values shown in Table 1. Further, the slagging rate and the dephosphorization lime efficiency are respectively calculated by the following equations. Slagification ratio = actual basicity of slag after dephosphorization / calculated basicity of slag after dephosphorization Dephosphorized lime efficiency = phosphorus concentration in slag after dephosphorization / lime concentration in slag after dephosphorization
【0026】[0026]
【表1】 [Table 1]
【0027】表1に示すとおり、脱炭スラグに蛍石を投
入してから凝固させた本発明の場合、比較例に比較し
て、脱りん精錬後のスラグの滓化率が約1.4倍、脱り
ん石灰効率が約2倍に上昇している。また、試験チャー
ジにおいてはスロッピングの発生は認められなかった。As shown in Table 1, in the case of the present invention in which fluorite was added to the decarburized slag and then solidified, the slagification ratio of the slag after the dephosphorization refining was about 1.4 as compared with the comparative example. The dephosphorization lime efficiency has increased about twice. No slopping was observed in the test charge.
【0028】[実施例2]250tの上底吹転炉におい
て、脱炭精錬末期にCaF2が炉内スラグの10%程度
となるように蛍石を投入した本発明の場合と、蛍石を投
入しない比較例の場合のそれぞれについて、溶鋼のMn
濃度を比較した。プロセスフローの概略を図2に示し、
その結果を表2に示す。[Example 2] In the case of the present invention in which fluorite was charged so that CaF 2 became about 10% of the slag in the furnace at the end of decarburization refining in a 250-t top-bottom blower, Mn of molten steel for each of comparative examples where
The concentrations were compared. An outline of the process flow is shown in FIG.
Table 2 shows the results.
【0029】[0029]
【表2】 [Table 2]
【0030】表2に示すとおり、比較例に比較して、溶
鋼のMn濃度は0.02〜0.03%上昇している。As shown in Table 2, the Mn concentration in the molten steel is increased by 0.02 to 0.03% as compared with the comparative example.
【0031】[0031]
【発明の効果】以上述べたとおり、本発明によれば、脱
炭スラグの顕熱を利用しつつスラグをリサイクルするこ
とが可能になり、スロッピングの発生率を低減し、リサ
イクルした脱炭スラグの脱りん吹錬時の滓化率を向上す
ることが可能であり、スロッピング防止や脱りん効率補
助のために使用していた石灰分を削減できる。また、脱
炭吹錬末期に、蛍石等を投入することにより、上記効果
に加え、スラグ中のMn酸化物を還元し、溶鋼[Mn]
を向上することができる。As described above, according to the present invention, it is possible to recycle slag while utilizing the sensible heat of decarburized slag, reduce the rate of occurrence of slopping, and recycle decarbonized slag. It is possible to improve the rate of slag formation during dephosphorization blowing, and to reduce lime used for preventing slopping and assisting dephosphorization efficiency. In addition, by adding fluorite or the like at the end of decarburization blowing, in addition to the above effects, Mn oxide in slag is reduced, and molten steel [Mn] is added.
Can be improved.
【図1】本発明法に係わる精錬プロセスの概念図であ
る。FIG. 1 is a conceptual diagram of a refining process according to the present invention.
【図2】実施例1のプロセスフローを示す図である。FIG. 2 is a diagram showing a process flow of the first embodiment.
【図3】実施例2のプロセスフローを示す図である。FIG. 3 is a diagram illustrating a process flow according to a second embodiment.
1 転炉 2 受湯鍋 3 滓鍋 4 溶銑鍋 5 溶鋼鍋 6 吹錬ランス 7 溶湯 8 スラグ DESCRIPTION OF SYMBOLS 1 Converter 2 Hot pot 3 Slag pot 4 Hot metal pot 5 Steel hot pot 6 Blowing lance 7 Melt 8 Slag
フロントページの続き (72)発明者 渡邊 国彦 君津市君津1番地 新日本製鐵株式会社君 津製鐵所内 Fターム(参考) 4K002 AC05 AC09 AE01 BD04 4K014 AA03 AB00 AB02 AB16 AB21 AD00 Continued on the front page (72) Inventor Kunihiko Watanabe 1 Kimitsu, Kimitsu, Nippon Steel Corporation Kimitsu Works F-term (reference) 4K002 AC05 AC09 AE01 BD04 4K014 AA03 AB00 AB02 AB16 AB21 AD00
Claims (2)
精錬を行い、その後転炉内溶湯を受湯鍋に排出し、つい
で溶湯排出後転炉内の脱りんスラグを排滓鍋に排出し、
前記受湯鍋に排出した溶湯を再度前記転炉に装入し、主
に脱炭精錬を行い、脱炭後溶鋼を排出した後、脱炭スラ
グを転炉内に残し、該残留した脱炭スラグに蛍石、Al
灰、ボロン酸化物の内の一種以上を含む副材を投入し、
次チャージの脱りん精錬に使用することを特徴とする製
鋼方法。In a converter, first, dephosphorization and refining are mainly performed, and thereafter, the molten metal in the converter is discharged to a receiving pan, and then, the dephosphorized slag in the converter is discharged to a waste pan. And
The molten metal discharged into the receiving pan is charged again into the converter, mainly decarburized and refined, and after the decarbonized molten steel is discharged, the decarburized slag is left in the converter, and the remaining decarbonized slag is left. Fluorite, Al
Add auxiliary material containing at least one of ash and boron oxide,
A steelmaking method characterized by being used for dephosphorization refining of the next charge.
精錬を行い、その後転炉内溶湯を受湯鍋に排出し、次い
で溶湯排出後、転炉内の脱りんスラグを排滓鍋に排出
し、前記受湯鍋に排出した溶湯を再度前記転炉に装入
し、主に脱炭精錬を行い、該脱炭精錬の末期に蛍石、A
l灰、ボロン酸化物の内の一種以上を含む副材を投入
し、脱炭後溶鋼を排出した後、脱炭スラグを転炉内に残
し、次チャージの脱りん精錬に使用することを特徴とす
る製鋼方法。2. In the converter, first, dephosphorization and refining are mainly performed first, and then, the molten metal in the converter is discharged to a receiving pan, and then the dephosphorized slag in the converter is discharged to a waste pan. The molten metal discharged and discharged into the hot pot was charged again into the converter, and mainly decarburized and refined. At the end of the decarburized refining, fluorite and A
Adds an auxiliary material containing at least one of ash and boron oxide, discharges molten steel after decarburization, leaves decarburized slag in the converter, and uses it for dephosphorization and refining of the next charge. And steel making method.
Priority Applications (1)
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JP6175699A JP2000256719A (en) | 1999-03-09 | 1999-03-09 | Steelmaking method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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JP6175699A JP2000256719A (en) | 1999-03-09 | 1999-03-09 | Steelmaking method |
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JP2000256719A true JP2000256719A (en) | 2000-09-19 |
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ID=13180332
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107557518A (en) * | 2017-09-14 | 2018-01-09 | 首钢京唐钢铁联合有限责任公司 | Dephosphorization converter bottom maintenance method |
CN108842027A (en) * | 2018-05-29 | 2018-11-20 | 华北理工大学 | A kind of dephosphorization converter finishing slag gasification dephosphorization method and smelting process |
-
1999
- 1999-03-09 JP JP6175699A patent/JP2000256719A/en not_active Withdrawn
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107557518A (en) * | 2017-09-14 | 2018-01-09 | 首钢京唐钢铁联合有限责任公司 | Dephosphorization converter bottom maintenance method |
CN107557518B (en) * | 2017-09-14 | 2019-11-19 | 首钢京唐钢铁联合有限责任公司 | A kind of dephosphorization converter furnace bottom maintaining method |
CN108842027A (en) * | 2018-05-29 | 2018-11-20 | 华北理工大学 | A kind of dephosphorization converter finishing slag gasification dephosphorization method and smelting process |
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