JP2001220621A - Method for refining molten steel - Google Patents
Method for refining molten steelInfo
- Publication number
- JP2001220621A JP2001220621A JP2000028626A JP2000028626A JP2001220621A JP 2001220621 A JP2001220621 A JP 2001220621A JP 2000028626 A JP2000028626 A JP 2000028626A JP 2000028626 A JP2000028626 A JP 2000028626A JP 2001220621 A JP2001220621 A JP 2001220621A
- Authority
- JP
- Japan
- Prior art keywords
- concentration
- slag
- hot metal
- cao
- phosphorus
- 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
Classifications
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- 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
- Treatment Of Steel In Its Molten State (AREA)
- 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】本発明はハロゲン化物を使用
せず、また高効率な鉄鋼精錬プロセスに関するものであ
って、銑鉄を原料とする鋼の精錬プロセスに広く利用さ
れる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-efficiency steel refining process that does not use a halide and is widely used in a steel refining process using pig iron as a raw material.
【０００２】[0002]
【従来の技術】鋼材使用環境の厳格化に伴い、鋼中に含
まれるりん、硫黄等の不純物元素の低減に対する要求は
厳しい。そこで、溶銑段階での脱珪、脱りん、脱硫事前
処理、いわゆる溶銑予備処理技術が開発され、転炉での
脱炭吹錬と組み合わせることにより、より効率的な不純
物除去方法として発展してきている。一方で、最近、環
境問題に対する社会的関心が高まる中、鉄鋼精錬工程に
おいて生じる様々な副産物の処理方法についても問題が
提起されている。特に、製鋼スラグに含まれるフッ素は
水中への溶出が問題とされており、フッ化物を用いない
プロセスの提案が望まれるところである。2. Description of the Related Art With the stricter use environment of steel materials, there is a severe demand for reduction of impurity elements such as phosphorus and sulfur contained in steel. Therefore, de-siliconization, de-phosphorization, and desulfurization pre-treatment at the hot metal stage, so-called hot metal pre-treatment technology, has been developed and combined with decarburization blowing in a converter, has been developed as a more efficient impurity removal method. . On the other hand, recently, with increasing public interest in environmental issues, problems have been raised regarding methods of treating various by-products generated in the steel refining process. In particular, elution of fluorine contained in steelmaking slag into water is considered to be a problem, and it is desired to propose a process using no fluoride.
【０００３】従来、りん、硫黄を安価に低減できる物質
としてCaO が主たる精錬剤として利用されてきたが、Ca
O 自体は融点が2000℃以上の高融点物質であり1700℃程
度を最高温度とする製鋼プロセスにおいてもCaO を単独
で溶融・滓化させてスラグと化することは困難であり従
来よりCaF2、CaCl2 などのハロゲン化物が併用されてき
た。一方、これらのハロゲン化物は精錬反応容器を構成
する耐火物の侵食も著しく促進するので、これらハロゲ
ン化物の種類、量を、目的や状況に応じて最適化して利
用しているのが現状である。しかし、上記環境問題に対
し、とくにフッ化物を全く使用しないというニーズに対
してはこれを達成するプロセスを構築するにはいたって
いない。Hitherto, CaO has been used as a main refining agent as a substance capable of reducing phosphorus and sulfur at low cost.
O itself has a melting point is difficult to singly by melting and slag formation slag and the CaO even in steelmaking processes between the maximum temperature of about 1700 ° C. There a refractory material above 2000 ° C. CaF 2 conventionally, Halides such as CaCl 2 have been used in combination. On the other hand, since these halides also significantly accelerate the erosion of refractories constituting the refining reaction vessel, the types and amounts of these halides are currently optimized and used according to the purpose and situation. . However, it has not been possible to establish a process for achieving the above environmental problems, especially for the need to use no fluoride at all.
【０００４】各種酸化物、ハロゲン化物添加によるCaO
の融点降下に関する研究は数多く行われており、工業的
規模での利用が容易なものにCaF2、Al2O3 がある。CaF2
の利用には前記環境上の問題、および耐火物保護の観点
から好ましくなく、その代替としてAl2O3 の利用方法に
関する検討が行われている。特公平6-17496 号公報には
溶銑予備処理工程における生石灰の滓化促進の目的でAl
2O3 を使用する記載がある。特開平8-41516 号公報には
溶銑での予備脱りんプロセスにおいて脱りん剤とともに
二次精錬滓を添加し、Al2O3 濃度を10〜30％に高める、
という記載も見られる。しかし、これらの方法は溶銑予
備処理段階での生石灰滓化促進に関するものである。し
かし、スラグにAl2O3 を含ませると著しい泡立ちを助長
することも知られている。特に、溶銑予備処理を施して
いない溶銑を用いた場合、転炉吹錬時に発生するスラグ
量が多くなり、スラグの泡立ちは精錬容器からのスラ
グ、溶銑流出をもたらし、実際上操業不可能になるので
好ましくない。そこで、本願発明者らは溶銑予備処理に
おいては蛍石などのハロゲン化を添加せず、微粉CaOを
用い、適正な塩基度、底吹き攪拌を与えるという方法を
開発し、特開平9-143529として公開したが、転炉吹錬時
のハロゲン化物を使用しない方法について新たに検討を
行ったものである。CaO by adding various oxides and halides
There have been many studies on melting point reduction of CaF 2 and Al 2 O 3 which are easy to use on an industrial scale. CaF 2
Utilization of Al is not preferable from the viewpoint of the above-mentioned environmental problems and protection of refractories. As an alternative, studies have been made on the use of Al 2 O 3 . Japanese Patent Publication No. 6-17496 discloses that Al is used to promote slagification of quicklime in the hot metal pretreatment process.
There is a description that uses 2 O 3 . Japanese Patent Application Laid-Open No. 8-41516 discloses that in a preliminary dephosphorization process with hot metal, a secondary smelting slag is added together with a dephosphorizing agent to increase the Al 2 O 3 concentration to 10 to 30%.
Is also seen. However, these methods relate to the promotion of quicklime slag formation in the hot metal pretreatment stage. However, it is also known that the inclusion of Al 2 O 3 in slag promotes significant foaming. In particular, when hot metal that has not been subjected to hot metal pretreatment is used, the amount of slag generated during converter blowing increases, and bubbling of slag causes slag and hot metal to flow out of the refining vessel, making it practically impossible to operate. It is not preferable. Therefore, the present inventors have developed a method of not adding halogen such as fluorite in the hot metal pretreatment, using fine powder CaO, and giving an appropriate basicity, and bottom-blowing agitation. Although it was made public, a new study was conducted on a method that does not use halides during converter blowing.
【０００５】一方、溶銑予備処理が広く一般的に採用さ
れている現状では採用される前に比べて転炉での脱りん
負荷が軽減され、転炉吹錬の単純化、高速化が達成され
高生産性を確保することができる。しかし、溶銑段階で
の予備脱りんプロセスでもそのばらつきは不可避的なも
のであり、最終目標りん濃度まで予備処理段階で下げら
れていない場合も生じる。そのため、転炉吹錬時におい
ても若干の脱りんを行う必要が生じる場合がある。その
場合、やはりCaO を添加して脱りんを行おうとするが、
前記の様にCaF2等の滓化促進剤を使用しない場合にはCa
O の滓化が十分ではなく、脱りんが進まず、りん濃度を
最終目標値以下にできない、という問題点があり、完全
に蛍石等ハロゲン化物を使用しない精錬方法は未だ確立
されていなかった。On the other hand, in the present situation where hot metal pretreatment is widely and generally employed, the dephosphorization load in the converter is reduced as compared with before the adoption, and simplification and speeding up of the converter blowing are achieved. High productivity can be secured. However, even in the preliminary dephosphorization process in the hot metal stage, the variation is inevitable, and there are cases where the final phosphorus concentration has not been lowered in the pretreatment stage. Therefore, it may be necessary to perform a slight dephosphorization even during converter blowing. In that case, try to remove phosphorus by adding CaO,
As described above, when no slagging accelerator such as CaF 2 is used, Ca
There is a problem that the slagging of O is not enough, dephosphorization does not progress, and the phosphorus concentration cannot be reduced below the final target value, and a refining method that does not completely use halides such as fluorite has not yet been established. .
【０００６】[0006]
【発明が解決しようとする課題】本願発明は前項に述べ
た課題を解決するためになされたものであり、蛍石など
のハロゲン化物を使用しなくとも有利に脱りんが可能な
転炉での精錬方法を提供するものである。DISCLOSURE OF THE INVENTION The present invention has been made to solve the problems described in the preceding paragraph, and is intended for use in a converter which can advantageously remove phosphorus without using a halide such as fluorite. It provides a refining method.
【０００７】[0007]
【課題を解決するための手段】本発明は、（１）溶銑の
脱炭吹錬を行うに祭し、りん濃度0.04％未満、珪素濃度
0.1%以下の溶銑を原料とし、蛍石などのハロゲン化物を
使用せず、スラグの塩基度(CaO/SiO 2)を3.0 以上、4 以
下の範囲とし、Al2O3 源を添加して最終スラグのAl2O3
濃度を3.5%以上とする溶鋼の精錬方法、（２）Al2O3 源
として、溶鋼精錬鍋耐火物の廃材を使用することを特徴
とする（１）記載の溶鋼の精錬方法、である。即ち、本
発明は、予備脱りん処理を施した溶銑を転炉で精錬して
溶鋼を得る方法において、蛍石などのハロゲン化物を使
用することなく、脱りんを促進して低りん鋼を安定して
得る方法を提供するものであり、従来、鉄鋼精錬に広く
採用されている転炉に広く適用可能な方法である。SUMMARY OF THE INVENTION The present invention provides (1) hot metal
Festival for decarburization blowing, phosphorus concentration less than 0.04%, silicon concentration
0.1% or less hot metal is used as raw material, and halides such as fluorite
Not used, basicity of slag (CaO / SiO Two) Is 3.0 or more, 4 or more
In the lower range, AlTwoOThreeAdd source to final slag AlTwoOThree
Refining method for molten steel with a concentration of 3.5% or more, (2) AlTwoOThreesource
It is characterized by the use of scrap metal refractory pot refractories
(1) The method for refining molten steel according to (1). That is, the book
The invention refined hot metal that had been subjected to preliminary dephosphorization in a converter
In the method of obtaining molten steel, a halide such as fluorite is used.
Without phosphorus, promotes dephosphorization and stabilizes low phosphorus steel
To provide a method for
This is a method that can be widely applied to converters that have been adopted.
【０００８】[0008]
【発明の実施の形態】溶銑予備処理を行った溶銑での転
炉吹錬は珪素濃度が低く、生成するSiO2量が少ないこと
から、スラグ量の少ないいわゆるレススラグ吹錬とな
る。この様な状態である程度の脱りん率を得ようとする
場合、高いりん分配比が必要となる。しかし、このため
にはスラグの塩基度を高める必要が生じる。一方、一般
に転炉や溶銑予備処理でのスラグの塩基度はその構成要
素であるCaO とSiO2濃度の比をとってCaO/SiO2で表すこ
とが広く行われているが、実際にはCaO として存在する
ものには３種類存在する。一つは他のスラグ構成要素で
あるSiO2やFeO 等と全く反応していないfreeなCaO であ
り、次に2CaO・ SiO2、3CaO・ SiO2等のカルシウムシリケ
ートを代表とする中間化合物であり、最後に溶融液相中
に存在するCaO である。これらの中でりんを含有する相
は後者２相であるために本来、塩基度としては未反応の
freeなCaO を除いたCaO 濃度を評価し、SiO2との濃度比
をとった塩基度と評価するのが正しいと思われる。BEST MODE FOR CARRYING OUT THE INVENTION Converter blowing with hot metal that has been subjected to hot metal pretreatment is so-called less slag blowing with a small amount of slag because the silicon concentration is low and the amount of generated SiO 2 is small. In order to obtain a certain dephosphorization rate in such a state, a high phosphorus distribution ratio is required. However, this requires increasing the basicity of the slag. On the other hand, generally the basicity of the slag in a converter furnace and molten iron pre-treatment is widely practiced represented by CaO / SiO 2 by taking the ratio of CaO and SiO 2 concentration of its components, but in practice CaO There are three types in what exists. One is a SiO 2 and FeO, etc. and not at all react free of CaO as other slag components, then the 2CaO · SiO 2, 3CaO · SiO 2 such as calcium silicate has an intermediate compound typified And finally, CaO present in the melt phase. Among these, the phase containing phosphorus is the latter two phases, and therefore, is basically unreacted as basicity.
It seems correct to evaluate the CaO concentration excluding free CaO and evaluate the basicity based on the concentration ratio with SiO 2 .
【０００９】一方、本願発明者らは転炉吹錬の際にAl2O
3 源を添加する試験を行い、以下の様な知見を得た。本
願発明はこの知見に基づくものである。第１図は本願発
明者らが行った試験において最終スラグのフリーCaO 濃
度とAl2O3 濃度の関係を示すが、不可避的に混入するAl
2O3 濃度が２％程度存在し、Al2O3 源を添加するととも
にAl2O3 濃度が増加し、それに伴い、フリーCaO 濃度は
減少する。即ち、生石灰の滓化が促進されていることが
わかる。On the other hand, the inventors of the present invention have found that Al 2 O
A test was conducted in which three sources were added, and the following findings were obtained. The present invention is based on this finding. FIG. 1 shows the relationship between the free CaO concentration and the Al 2 O 3 concentration of the final slag in the test conducted by the inventors of the present invention.
The 2 O 3 concentration is about 2%, the Al 2 O 3 concentration increases with the addition of the Al 2 O 3 source, and the free CaO concentration decreases accordingly. That is, it can be seen that slag formation of quicklime is promoted.
【００１０】第２図(a) は温度1600℃、FeO 濃度17％、
MnO 濃度7.1%とした時の液相領域の計算結果を示す。こ
の結果に基づき、液相100%に保つのに必要なAl2O3 濃度
を求めた結果を第２(b) 図に示す。これによると塩基度
が3.5 の場合、液相100%にするために必要なAl2O3 濃度
は3.5%である。一方、第２図(c) には熱力学平衡計算に
よる平衡りん分配比を示すが、塩基度が3.0 以上あれば
処理前りん濃度0.04％の溶銑を0.02％まで脱りんするの
に必要な分配比70以上を確保可能であることがわかる。
しかし、これ以下ではりん分配比は低く、脱りんが出来
なくなる。また塩基度をこれ以上とするためには必要な
Al2O3 濃度が7%以上に増加するため多量のAl2O3 を添加
する必要が生じる。従って、スラグの塩基度は3.0 〜4.
0(第２図(b) のＣ、Ｄ、Ｅ、Ｆ）とし、Al2O3 添加量は
3.5%以上とするのが望ましい。ただし、Al2O3 の多量添
加はフォーミングを助長し、操業が不可能になること、
また一般に転炉耐火物として利用されているMgO 系レン
ガの溶損が顕著になることから、自ずと添加する量には
限界があるが、3.5%以上を確保すれば良い。FIG. 2 (a) shows a temperature of 1600 ° C., an FeO concentration of 17%,
The calculation results of the liquid phase region when the MnO concentration is 7.1% are shown. Based on this result, the result of obtaining the Al 2 O 3 concentration necessary to maintain the liquid phase at 100% is shown in FIG. 2 (b). According to this, when the basicity is 3.5, the Al 2 O 3 concentration required to make the liquid phase 100% is 3.5%. On the other hand, Fig. 2 (c) shows the equilibrium phosphorus distribution ratio by thermodynamic equilibrium calculation. If the basicity is 3.0 or more, the distribution necessary for dephosphorizing hot metal with a phosphorus concentration of 0.04% before treatment to 0.02% is obtained. It can be seen that a ratio of 70 or more can be secured.
However, below this, the phosphorus distribution ratio is low and dephosphorization cannot be performed. It is also necessary to increase the basicity
Since the Al 2 O 3 concentration increases to 7% or more, it is necessary to add a large amount of Al 2 O 3 . Therefore, the basicity of slag is 3.0-4.
0 (C, D, E, F in FIG. 2 (b)) and the amount of Al 2 O 3 added
It is desirable to be 3.5% or more. However, the addition of a large amount of Al 2 O 3 promotes forming, making operation impossible.
In addition, since the erosion of MgO-based bricks generally used as converter refractories becomes remarkable, the amount to be added is naturally limited, but it is sufficient to secure 3.5% or more.
【００１１】Al2O3 源としてはボーキサイト等の鉱物を
添加する方法もとり得るが、一般に鉄鋼精錬過程で用い
られる取鍋の耐火物を解体、再築造する際に発生するレ
ンガ屑を再利用する方法が廃棄物量低減の観点からも好
ましい。また、この場合、粒径10mm〜30mm程度の塊状に
荒粉砕して転炉にて上方添加して利用するのが簡便であ
り、利用し易い。As a source of Al 2 O 3, a method of adding a mineral such as bauxite can be used. In general, brick waste generated when disassembling and rebuilding a refractory of a ladle used in a steel refining process is reused. The method is also preferable from the viewpoint of reducing the amount of waste. Also, in this case, it is convenient and easy to roughly pulverize into a lump having a particle size of about 10 mm to 30 mm and add it upward in a converter for use.
【００１２】[0012]
【実施例】（実施例）溶銑予備処理工程にてりん濃度0.
025 〜0.038%、珪素濃度0.1%以下に事前処理した溶銑を
転炉に装入し、生石灰とAl2O3 源を上方添加して酸素ガ
スを上吹きし、脱炭吹錬を行った。なお、ハロゲン化物
は一切添加しなかった。この時、最終的に生成したスラ
グの組成としてAl2O3 濃度が3.5 〜５％に達したが、フ
リーなCaO の濃度は7%以下であった。得られたりん分配
比は90以上であった。処理前後のりん濃度は第１表に示
す結果となった。 （比較例１）溶銑予備処理工程にてりん濃度を0.025 〜
0.036%、珪素濃度0.1%以下に事前処理した溶銑を転炉に
装入し、生石灰を上方添加して酸素ガスを上吹きし、脱
炭吹錬を行った。なお、ハロゲン化物は一切使用しなか
った。この時、最終スラグ中Al2O3 濃度は３％以下であ
りフリーCaO 濃度は10％以上と高い濃度であった。りん
分配比は40〜90の範囲であった。 （比較例２）溶銑予備処理した溶銑283t〜304tを転炉に
装入し生石灰と、生石灰の滓化を促進するための蛍石を
使用し、酸素ガスを上吹きして脱炭吹錬を行った。この
場合、脱りんは良好であったが、排出したスラグからの
フッ素溶出量が多く、これを抑制するための新たな手段
が必要であることが分かった。Example (Example) Phosphorus concentration of 0.
The hot metal pretreated to a concentration of 025 to 0.038% and a silicon concentration of 0.1% or less was charged into a converter, a quick lime and an Al 2 O 3 source were added upward, oxygen gas was blown upward, and decarburization blowing was performed. No halide was added. At this time, the Al 2 O 3 concentration finally reached 3.5 to 5% as a composition of the generated slag, but the free CaO concentration was 7% or less. The obtained phosphorus distribution ratio was more than 90. The phosphorus concentrations before and after the treatment were as shown in Table 1. (Comparative Example 1) In the hot metal pretreatment step, the phosphorus concentration was 0.025 to
Hot metal pretreated to 0.036% and silicon concentration of 0.1% or less was charged into a converter, quick lime was added upward, oxygen gas was blown upward, and decarburization blowing was performed. No halide was used. At this time, the Al 2 O 3 concentration in the final slag was 3% or less, and the free CaO concentration was as high as 10% or more. The phosphorus distribution ratio was in the range of 40-90. (Comparative Example 2) Hot metal pretreated hot metal 283t to 304t was charged into a converter, and quick lime and fluorite for promoting slagging of quick lime were used. went. In this case, although the dephosphorization was good, the amount of fluorine eluted from the discharged slag was large, and it was found that a new means for suppressing this was required.
【００１３】[0013]
【表１】 ※ただし、塩基度は次式で表すフリーCaO 補正後の値を
示す。 ((CaO)-free(CaO))/(SiO2 )[Table 1] * However, the basicity shows the value after free CaO correction expressed by the following formula. ((CaO) -free (CaO)) / (SiO 2 )
【００１４】[0014]
【発明の効果】本発明によれば、転炉吹錬時に蛍石など
のハロゲン化物を使用することなく、しかも脱りん能力
を確保した処理が可能となる。According to the present invention, it is possible to perform a treatment which does not use a halide such as fluorite at the time of blowing the converter and which has a sufficient dephosphorization ability.
【図１】転炉吹錬後のスラグ中Al2O3 濃度とフリーCaO
濃度の関係を示す図である。Fig. 1 Al 2 O 3 concentration in slag after converter blowing and free CaO
It is a figure which shows the relationship of density.
【図２】本願発明に至る過程で得た計算状態図で、図２
(a) はFeO 17％、MnO7.1%一定下、1600℃における液相
領域を示す図、図２(b) はFeO 17％、MnO 7.1%一定下、
1600℃での各塩基度における、液相率100%を得るに必要
なAl2O3 濃度を示す図、図２(c) は平衡りん分配比に及
ぼす塩基度の影響を示す図である。FIG. 2 is a calculation state diagram obtained in a process leading to the present invention.
(a) is a diagram showing a liquid phase region at 1600 ° C. under a constant condition of 17% FeO and 7.1% MnO. FIG. 2 (b) is a diagram illustrating a liquid phase region under a constant condition of 17% FeO and 7.1% MnO.
FIG. 2C shows the Al 2 O 3 concentration required to obtain a liquid phase ratio of 100% at each basicity at 1600 ° C. FIG. 2C shows the effect of basicity on the equilibrium phosphorus distribution ratio.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 國武 意智 愛知県東海市東海町５−３ 新日本製鐵株 式会社名古屋製鐵所内 Ｆターム(参考） 4K002 AE01 AE02 4K013 BA03 CB09 EA00 EA05 4K014 AA03 AB01 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Satoshi Kunitake 5-3 Tokai-cho, Tokai-shi, Aichi F-term in Nippon Steel Corporation Nagoya Works (reference) 4K002 AE01 AE02 4K013 BA03 CB09 EA00 EA05 4K014 AA03 AB01
Claims (2)
0.04％未満、珪素濃度0.1%以下の溶銑を原料とし、蛍石
などのハロゲン化物を使用せず、スラグの塩基度(CaO/S
iO2)を3.0 以上、4 以下の範囲とし、Al2O3 源を添加し
て最終スラグのAl2O3 濃度を3.5%以上とする溶鋼の精錬
方法。Claims 1. Dephosphorization of hot metal, phosphorus concentration
The raw material is hot metal with a concentration of less than 0.04% and a silicon concentration of 0.1% or less, without the use of halides such as fluorite, and the basicity of slag (CaO / S
A method for refining molten steel in which iO 2 ) is in the range of 3.0 to 4, and an Al 2 O 3 source is added to make the final slag Al 2 O 3 concentration 3.5% or more.
材を使用することを特徴とする請求項１記載の溶鋼の精
錬方法。2. The method for refining molten steel according to claim 1, wherein a waste material of a refractory in a molten steel refining pot is used as the Al 2 O 3 source.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003147426A (en) * | 2001-11-14 | 2003-05-21 | Sumitomo Metal Ind Ltd | Steelmaking method |
| JP2004249151A (en) * | 2003-02-18 | 2004-09-09 | Denki Kagaku Kogyo Kk | Exhaust gas treatment material, gas filter, and exhaust gas treatment method using them |
| US7438740B2 (en) * | 2003-03-07 | 2008-10-21 | Koyo Seiko Co. Ltd. | Briquette for raw material for iron manufacture and briquette for introduction into slag generating apparatus |
| JP2013036055A (en) * | 2011-08-03 | 2013-02-21 | Nippon Steel & Sumitomo Metal Corp | Method of decarburizing molten iron |
-
2000
- 2000-02-07 JP JP2000028626A patent/JP3704267B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003147426A (en) * | 2001-11-14 | 2003-05-21 | Sumitomo Metal Ind Ltd | Steelmaking method |
| JP2004249151A (en) * | 2003-02-18 | 2004-09-09 | Denki Kagaku Kogyo Kk | Exhaust gas treatment material, gas filter, and exhaust gas treatment method using them |
| JP4615829B2 (en) * | 2003-02-18 | 2011-01-19 | 電気化学工業株式会社 | Exhaust gas treatment material, gas filter, and exhaust gas treatment method using them |
| US7438740B2 (en) * | 2003-03-07 | 2008-10-21 | Koyo Seiko Co. Ltd. | Briquette for raw material for iron manufacture and briquette for introduction into slag generating apparatus |
| JP2013036055A (en) * | 2011-08-03 | 2013-02-21 | Nippon Steel & Sumitomo Metal Corp | Method of decarburizing molten iron |
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