JPH08239704A - Method for charging raw material in blast furnace - Google Patents
Method for charging raw material in blast furnaceInfo
- Publication number
- JPH08239704A JPH08239704A JP14694295A JP14694295A JPH08239704A JP H08239704 A JPH08239704 A JP H08239704A JP 14694295 A JP14694295 A JP 14694295A JP 14694295 A JP14694295 A JP 14694295A JP H08239704 A JPH08239704 A JP H08239704A
- Authority
- JP
- Japan
- Prior art keywords
- raw material
- charging
- iron raw
- iron
- layer
- 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
- Manufacture Of Iron (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、粒度範囲の広い鉱石類
や還元鉄ならびにスクラップを装入するに当り、効率良
く装入し、細粒焼結鉱を多量に使用する高炉操業方法に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a blast furnace in which ores having a wide grain size range, reduced iron and scrap are charged efficiently and a large amount of fine-grained sintered ore is used.
【０００２】[0002]
【従来の技術】高炉へのスクラップ使用技術について
は、１９８３年にフランスのＲｏｍｂａｓ工場にて、
スクラップ１００％使用の操業試験（Ｊ−Ｐ Ｂｉｒａ
ｔら：ＣＡＭＰ−ＩＳＩＪ．６（１９９３）．ｐ１０２
４）が行われている。また、特開昭６３−１３７１１
０号公報の「高炉での低Ｓｉ濃度溶銑の製造方法」に記
載されているようなものが知られている。しかし、スク
ラップ類を使用するに際し、スクラップの特徴を効率良
く活用することを考えた装入方法に関する報告はない。2. Description of the Related Art Regarding the technique of using scrap for a blast furnace, in 1983, at the Rombas factory in France,
Operation test using 100% scrap (JP Bira
t et al .: CAMP-ISIJ. 6 (1993). p102
4) is being performed. Also, JP-A-63-13711
There is known one as described in "Production Method of Hot Metal with Low Si Concentration in Blast Furnace" in JP-B-0. However, when using scraps, there is no report on the charging method considering efficient utilization of scrap characteristics.
【０００３】高炉への細粒焼結鉱使用技術については、
炉周辺部の粗粒鉱石層上へ細粒焼結鉱を装入する方法
（ＩＳＩＪ．Ｖｏｌ．７（１９９４）．ｐ１５８），
炉周辺部のコークス層上へ細粒焼結鉱を装入する方法
（特公昭５９−４１４８２号公報），粗粒鉱石と混合
して炉周辺部または炉周辺部から炉中間部に装入する方
法（鉄と鋼、７８（１９９２），ｐ１３３０）等があ
る。Regarding the technique of using fine-grained sintered ore in a blast furnace,
A method of charging fine-grained ore on the coarse-grained ore layer in the periphery of the furnace (ISIJ. Vol. 7 (1994). P158),
A method of charging fine-grained sintered ore onto the coke layer in the peripheral part of the furnace (Japanese Patent Publication No. 59-41482), mixing it with coarse-grained ore, and charging it into the middle part of the furnace from the peripheral part of the furnace or from the peripheral part of the furnace. Methods (iron and steel, 78 (1992), p1330) and the like.
【０００４】なお、高炉に装入する焼結鉱のサイズは、
５〜５０ｍｍを主として使用しており、焼結鉱歩留まり
は７０〜９０％である。ここで、１〜５ｍｍの細粒焼結
鉱が高炉で使用できれば焼結鉱歩留まりの向上になり、
経済的効果は非常に大きい。しかし、細粒焼結鉱の装入
により炉内の通気抵抗が増大するため、高出銑比を維持
しながら細粒焼結鉱を多量に使用することは困難とされ
ている。The size of the sintered ore charged into the blast furnace is
5 to 50 mm is mainly used, and the yield of sinter is 70 to 90%. Here, if fine-grained sintered ore of 1 to 5 mm can be used in the blast furnace, the yield of the sintered ore will be improved,
The economic effect is very large. However, it is considered difficult to use a large amount of fine-grained sinter while maintaining a high tap ratio because charging of fine-grained sinter increases ventilation resistance in the furnace.
【０００５】コークスや鉄原料は高炉の炉頂部から交互
に投入されるが、その投入方法は、例えば特開平２−２
００７０８号公報および特開平３−１３５１３号公報に
記載された「高炉操業方法」のように、下層から上層へ
向かって、コークス下層（以下、１Ｃ）、コークス上層
（以下、２Ｃ）、鉄原料下層（（以下、１Ｏ），鉄原料
上層（以下、２Ｏ）というように、コークスと鉄原料と
を複数層に分けて所定順序で装入している。Coke and iron raw materials are alternately charged from the top of the blast furnace, and the charging method is, for example, Japanese Patent Laid-Open No. 2-2.
Coke lower layer (hereinafter, 1C), coke upper layer (hereinafter, 2C), iron raw material lower layer, from the lower layer to the upper layer, as in “Blast furnace operating method” described in JP-A-00708 and JP-A-3-13513. ((Hereinafter, 10), iron raw material upper layer (hereinafter, 2O), the coke and the iron raw material are divided into a plurality of layers and charged in a predetermined order.
【０００６】[0006]
【発明が解決しようとする課題】ところで、鉄原料から
溶銑が得られるのは、コークス燃焼により発生するＣＯ
を用いた鉄原料の還元反応によるので、鉄原料層の下層
側ほど炉内で発生したＣＯとの接触性が良い。これによ
り、鉄原料下層である１Ｏの還元は充分に行われるが、
この還元時にＣＯが消費されて鉄原料上層である２Ｏの
還元性が低下してしまい、同じ１チャージ分の鉄原料層
の上下において還元率に大きな差が生じるという問題点
があった。By the way, hot metal can be obtained from an iron raw material by CO generated by coke combustion.
Because of the reduction reaction of the iron raw material using, the lower layer side of the iron raw material layer has better contact with CO generated in the furnace. As a result, reduction of 1O, which is the lower layer of the iron raw material, is sufficiently performed,
At the time of this reduction, CO is consumed and the reducing property of 2O, which is the upper layer of the iron raw material, is reduced, and there is a problem that there is a large difference in the reduction rate between the upper and lower iron raw material layers for the same charge.
【０００７】また、高炉への還元鉄やスクラップの使用
技術については、従来技術では１００％スクラップの
溶解試験を行ってはいるが、スクラップの溶解に対し、
装置として高炉を使用したもので、高炉操業にスクラッ
プを利用したものではない。従来技術は高炉に装入す
る原料にスクラップ（炭素含有量０．４５重量％以下、
平均０．３重量％）を加えて装入し、溶銑中のＳｉ濃度
を制御するためになされたものであるが、これは、還元
熱が不要であるスクラップを使用して燃料比を下げる手
段として活用したものである。粒度範囲の広い鉱石類を
効率良く使用するための鉱石層の通気性改善や鉱石層の
還元効率の向上さらには、細粒焼結鉱の多量使用を効率
良く行うためのスクラップ装入法、活用法について検討
した従来技術は、これまでのところ見当たらない。Regarding the technology of using reduced iron and scrap in the blast furnace, although the prior art has conducted a 100% scrap dissolution test,
Blast furnace is used as the equipment, and scrap is not used for blast furnace operation. In the conventional technology, scrap (carbon content 0.45% by weight or less,
This was done to control the Si concentration in the hot metal by adding (average 0.3% by weight), and this is a means for reducing the fuel ratio by using scrap that does not require heat of reduction. It was used as. Improving the permeability of the ore layer and improving the reduction efficiency of the ore layer to efficiently use ores with a wide grain size range. Furthermore, the scrap charging method and utilization to efficiently use a large amount of fine-grained ore So far, no prior art that has examined the law has been found.
【０００８】また、細粒焼結鉱の使用技術に関しては、
従来技術では、炉周辺部に細粒焼結鉱を装入しても、
次バッチのコークス装入の際に炉中心部への細粒焼結鉱
の流れ込みや細粒焼結鉱の円周方向のバランス崩れが生
じ、中心ガス流の阻害や周辺ガス流の不均一を招きやす
いという問題がある。また、従来技術では、と同様
に炉中心部への細粒焼結鉱の流れ込みが起きやすいこと
に加え、細粒焼結鉱単独装入の場合、周辺ガス流が強い
ため細粒焼結鉱が吹き飛ばされ易く所定の位置に装入す
ることが困難である。さらに、粒径の小さい細粒焼結鉱
が粒径の大きいコークスの間に入り込む、いわゆる浸透
により、コークス層の空隙率を低下させる場合がある。
そして、従来技術の場合、鉱石層の空隙率が低下する
ため、通気抵抗の増大による還元率の低下を招きやす
い。以上の理由により、細粒焼結鉱を多量に使用した場
合、安定した高炉操業を行うことが困難であった。Regarding the technique of using fine-grained sintered ore,
In the conventional technology, even if fine-grained sintered ore is charged in the periphery of the furnace,
When the next batch of coke was charged, the fine-grained sinter flowed into the center of the furnace or the fine-grained sinter became unbalanced in the circumferential direction, which hindered the central gas flow and caused non-uniformity of the peripheral gas flow. There is a problem that it is easy to invite. In addition, in the conventional technology, in addition to the fact that the fine-grained sintered ore is likely to flow into the center of the furnace in the same manner as in, when the fine-grained sintered ore alone is charged, the surrounding gas flow is strong and Are easily blown off and it is difficult to insert them in a predetermined position. Further, the fine porosity of the coke layer may be reduced due to so-called infiltration, in which fine-grained sintered ore having a small grain size enters between cokes having a large grain size.
In the case of the conventional technique, since the porosity of the ore layer is reduced, the reduction rate is likely to be reduced due to the increase in ventilation resistance. For the above reasons, it was difficult to perform stable blast furnace operation when a large amount of fine-grained sintered ore was used.
【０００９】本発明はかかる事情に鑑みてなされたもの
で、鉄原料層の全域にわたって良好な還元率を実現する
ための還元鉄あるいはスクラップあるいは小塊コークス
の使用法を提供し、また細粒焼結鉱の炉中心部への流れ
込みを防止し、かつ細粒焼結鉱の装入による空隙率低下
を極力抑制することにより、炉内通気抵抗の増大を抑制
し、高炉での細粒焼結鉱の多量使用を可能とし、燃料比
の低減などが図れる高炉操業方法を提供することを目的
とする。The present invention has been made in view of the above circumstances, and provides a method of using reduced iron or scrap or small coke in order to achieve a good reduction rate over the entire area of the iron raw material layer, and fine grain firing. Preventing the flow of slag into the center of the furnace, and suppressing the decrease in porosity due to the charging of fine-grained sintered ore as much as possible, suppresses the increase of ventilation resistance in the furnace and fine-grained sintering in the blast furnace. It is an object of the present invention to provide a blast furnace operating method that enables a large amount of ore to be used and can reduce the fuel ratio.
【００１０】[0010]
【課題を解決するための手段】本発明の高炉操業法は、
かかる課題を解決するため、 （１）高炉の炉頂から鉄原料を１バッチ以上連続装入し
て鉄原料層を形成した後、コークスを１バッチ以上連続
装入してコークス層を形成することを１サイクルとする
高炉の原料装入方法において、還元鉄及び／またはスク
ラップを鉄原料層の中層部および／または上層部に装入
することを特徴とする。 （２）高炉の炉頂から鉄原料を１バッチ以上連続装入し
て鉄原料層を形成した後、コークスを１バッチ以上連続
装入してコークス層を形成する高炉の原料装入方法にお
いて、前記鉄原料を篩分けし、平均粒度の大きい順に複
数バッチで装入して、平均粒度の異なる複数の層とし、
鉄原料層の上層部に、還元鉄及び／またはスクラップを
装入することを特徴とする。The blast furnace operating method of the present invention comprises:
In order to solve such a problem, (1) one or more batches of iron raw material are continuously charged from the furnace top of a blast furnace to form an iron raw material layer, and then one or more batches of coke are continuously charged to form a coke layer. In the method for charging a raw material for a blast furnace in which 1 cycle is performed, reduced iron and / or scrap is charged into the middle layer portion and / or the upper layer portion of the iron raw material layer. (2) In a raw material charging method for a blast furnace, which comprises continuously charging one or more batches of iron raw material from the top of the blast furnace to form an iron raw material layer, and then continuously charging one or more batches of coke to form a coke layer, The iron raw material is sieved, charged in a plurality of batches in descending order of average particle size to form a plurality of layers having different average particle sizes,
It is characterized in that reduced iron and / or scrap is charged in the upper portion of the iron raw material layer.
【００１１】（３）高炉の炉頂から鉄原料を２バッチで
装入した後に、コークスを２バッチで装入することを１
サイクルとする高炉の原料装入方法において、鉄原料の
１回目のバッチの粒度構成を１５ｍｍ以上５０ｍｍ以下
として鉄原料の下層部を形成し、鉄原料の２回目のバッ
チの粒度構成を５ｍｍ以上１５ｍｍ未満として鉄原料の
上層部を形成し、装入鉄原料の５〜２５ｗｔ％を１ｍｍ
以上５ｍｍ未満の細粒鉄原料として１回目のコークス装
入バッチに混合した後、前記鉄原料の上層部に装入する
ことを特徴とする。 （４）鉄原料の２回目の装入バッチの粒度５ｍｍ以上１
５ｍｍ未満の鉄原料に、粒度３ｍｍ以上１５ｍｍ以下の
小塊コークスを混合した後、装入して鉄原料の上層部を
形成することを特徴とする（３）記載の高炉の操業方
法。 （５）上記（３）、（４）記載の高炉の原料装入方法に
おいて、鉄原料層の上層部に還元鉄及び／またはスクラ
ップを装入することを特徴とする。(3) To charge the iron raw material from the top of the blast furnace in two batches and then to load the coke in two batches.
In the blast furnace raw material charging method using a cycle, the lower layer portion of the iron raw material is formed by setting the grain size composition of the first batch of iron raw material to 15 mm or more and 50 mm or less, and the grain size composition of the second batch of iron raw material is 5 mm or more and 15 mm or more. The upper layer of the iron raw material is formed as less than 5% by weight of the iron raw material
It is characterized in that, as a fine iron raw material having a size of less than 5 mm, it is mixed in the first coke charging batch and then charged into the upper layer portion of the iron raw material. (4) Grain size of the second charging batch of iron raw material 5 mm or more 1
(3) The method for operating a blast furnace according to (3), characterized in that an iron raw material of less than 5 mm is mixed with a small coke having a grain size of 3 mm or more and 15 mm or less and then charged to form an upper layer portion of the iron raw material. (5) In the blast furnace raw material charging method described in (3) and (4) above, reduced iron and / or scrap is charged into the upper layer of the iron raw material layer.
【００１２】[0012]
【作用】図１は還元ガス中のＣＯ濃度と、鉄原料層の高
さとの関係を示すグラフであり、鉄原料は、小塊コーク
ス、焼結鉱、ペレット、塊鉱石などを所定の配合比率で
混ぜ合わせたものである。鉄原料層４０ｃｍに対し、高
さ２０ｃｍのところで上下層に分かれている。最初に、
還元鉄ならびにスクラップの装入を鉄原料層の中層部お
よび／または上層部に限定し、鉄原料層の下層部には装
入しない装入法について説明する。FIG. 1 is a graph showing the relationship between the CO concentration in the reducing gas and the height of the iron raw material layer. As the iron raw material, small coke, sinter ore, pellets, lump ore, etc. are mixed in a predetermined proportion. It was mixed with. It is divided into upper and lower layers at a height of 20 cm with respect to the iron raw material layer of 40 cm. At first,
A charging method will be described in which charging of reduced iron and scrap is limited to the middle layer portion and / or upper layer portion of the iron raw material layer and not to the lower layer portion of the iron raw material layer.
【００１３】鉄原料層が炉下部に降下し、軟化・融着に
至るが、最初に軟化・融着する部分は、還元率の低い部
分であり、通常、鉄原料層の上部層である。還元鉄ある
いはスクラップ類の鉄原料層への混合は、高温性状を改
善するのに有効であるが、高炉に装入する還元鉄あるい
はスクラップ類の使用量がその品質や価格によって制約
される。そのため、より効率良く、その特徴を活用する
方法が望まれていた。本発明では、還元鉄あるいはスク
ラップ類の大部分を鉄原料層で還元率の低い中層部から
上層部にかけて、好ましくは上層部に集中して装入し、
鉄原料層の下層部には装入しない方法が有効である。The iron raw material layer descends to the lower part of the furnace and is softened / fused. The first softened / fused portion is a portion having a low reduction rate and is usually an upper layer of the iron raw material layer. Mixing of reduced iron or scraps into the iron raw material layer is effective for improving the high temperature property, but the amount of reduced iron or scraps to be charged into the blast furnace is limited by its quality and price. Therefore, there has been a demand for a more efficient method of utilizing the characteristics. In the present invention, most of the reduced iron or scraps in the iron raw material layer from the low reduction middle layer portion to the upper layer portion, preferably concentratedly charged in the upper layer portion,
It is effective to not charge the lower part of the iron raw material layer.
【００１４】還元鉄あるいはスクラップ類を鉱石と混合
使用すると、鉱石に対しスクラップのほうが収縮抵抗が
大きいため、鉱石のみの層に比べ、スクラップを含む鉱
石層のほうが収縮し難く、鉱石層の空隙部を高温まで確
保できることが一因である。また、鉱石層の空隙部が確
保されると、ガス還元により、鉱石類の還元も促進さ
れ、ガス還元により、鉱石類の還元も促進され、鉄原料
層の還元率の向上、鉄原料層の通気性の改善などの効果
が認められる。When reduced iron or scraps are mixed and used with ore, the scrap has a greater shrinkage resistance to the ore, and therefore the ore layer containing scrap is less likely to shrink than the layer containing only the ore, and the void portion of the ore layer is less likely to shrink. This is partly because it can secure high temperature. Further, when the void portion of the ore layer is secured, the reduction of the ores is promoted by the gas reduction, the reduction of the ores is promoted by the gas reduction, the reduction rate of the iron raw material layer is improved, and the iron raw material layer is reduced. Effects such as improved breathability are recognized.
【００１５】還元鉄、スクラップの装入部位について
は、鉄原料層の上層部（通常２Ｏ装入部位）に集中して
装入するほうが、鉄原料層の還元率の向上、通気性の改
善効果が大きい。これは、鉄原料層の下層部（通常１Ｏ
装入部位）の還元は良好であり、高炉内での鉄原料層の
高温性状、特に軟化・溶融性状を支配する要因は、鉄原
料層の上層部の高温性状であり、この上層部の高温性状
を改善することは、鉄原料層全体の高温性状を改善する
ことに相当する。そのため、本発明では、鉄原料層の上
層部の還元鉄あるいはスクラップ類を混合使用した。Concerning the charging site of reduced iron and scrap, it is better to concentrate the charging in the upper layer part of the iron raw material layer (usually the 2O charging site) in order to improve the reduction rate of the iron raw material layer and improve the air permeability. Is big. This is the lower part of the iron raw material layer (usually 10
The reduction of the charging site is good, and the factor that governs the high-temperature properties of the iron raw material layer in the blast furnace, especially the softening / melting properties, is the high-temperature properties of the upper layer portion of the iron raw material layer. Improving the properties corresponds to improving the high temperature properties of the entire iron raw material layer. Therefore, in the present invention, reduced iron or scraps in the upper layer of the iron raw material layer are mixed and used.
【００１６】還元鉄については、好ましくは粒度１〜１
５ｍｍ、予備還元率７０％以上のもので、その使用量が
多いほど、高温性状の改善効果が認められるが、価格が
高いため、使用量が制限される。スクラップ品質として
は不純物（Ｃｕ，Ｓｎ，Ｚｎなど）の制約があり、極力
清浄なものが望ましい。ここでいうスクラップとは、荒
雑銑、粒鉄、製鋼屑、磁選塊、シュレッダー屑などであ
り、粒度は１〜２０ｍｍに調整されていることが好まし
い。The reduced iron preferably has a particle size of 1 to 1.
5 mm and a pre-reduction rate of 70% or more, the higher the amount used, the higher the effect of improving the high-temperature properties, but the higher the price, the more the amount used is limited. The quality of scrap is restricted by impurities (Cu, Sn, Zn, etc.), and it is desirable to be as clean as possible. The scrap referred to here is coarse pig iron, granular iron, steel scraps, magnetically separated lumps, shredder scraps, etc., and the grain size is preferably adjusted to 1 to 20 mm.
【００１７】スクラップの使用量の上限については、ス
クラップ品質や生産鋼種によって異なる。比較的清浄な
スクラップを使用する場合、スクラップ中のＣｕ含有量
は０．１５％程度である。溶銑中のＣｕ含有量を０．０
１％、熱延可能な鋼中Ｃｕ含有量を０．０４％とする
と、スクラップ上限使用量は２１０ｋｇ／ｔ程度とな
る。ただし、型鋼など、比較的グレードの低い鋼種を生
産する場合には、その上限量は高くなる。また、グレー
ドの低いスクラップを使用する場合、スクラップ中のＣ
ｕ含有量は０．３％であり、この場合、高級鋼製造のた
めのスクラップ上限使用量は１００ｋｇ／ｔ程度であ
る。The upper limit of the amount of scrap used depends on the quality of scrap and the type of steel produced. When using relatively clean scrap, the Cu content in the scrap is about 0.15%. Cu content in the hot metal is 0.0
If the Cu content in the hot-rollable steel is 1% and the Cu content is 0.04%, the upper limit of scrap usage is about 210 kg / t. However, in the case of producing steel grades of relatively low grade, such as shape steel, the upper limit is high. When using low grade scrap, C in the scrap is used.
The u content is 0.3%, and in this case, the upper limit amount of scrap used for producing high-grade steel is about 100 kg / t.
【００１８】つぎに、還元鉄及び／またはスクラップを
鉄原料層の上層部に装入する装入法において、鉄原料層
を平均粒度の異なる複数の層とし、平均粒度の小さい鉄
原料を上層部に装入積層することが有効なことを説明す
る。高炉の炉頂部より、１チャージ分の鉄原料を、例え
ば上下２層に分けて装入するにあたって、装入される鉄
原料が上下２層とも、同じ粒度構成の原料であると、図
１のグラフの破線ａに示すように、鉄原料層の下層部に
おいて、還元ガス中のＣＯ濃度は３０．０％から１２．
５％程度へと比較的変化が大きく、その分だけ多くのＣ
Ｏが鉄原料の還元に利用されるが、鉄原料層の上層部に
おいては、還元ガス中のＣＯ濃度はほぼ１２．５％から
１２％程度までと比較的変化が小さく、少量のＣＯだけ
しか鉄原料の還元に利用されていない。そのため、図２
の鉄原料還元率と、鉄原料層の高さとの関係を示すグラ
フの破線ａに示すように、鉄原料層の上層部の還元率が
低い。Next, in the charging method for charging reduced iron and / or scrap into the upper layer of the iron raw material layer, the iron raw material layer is formed into a plurality of layers having different average particle sizes, and the iron raw material having a small average particle size is used as the upper layer portion. It will be explained that charging and stacking is effective. From the furnace top of the blast furnace, when charging one charge of iron raw material in two layers, for example, upper and lower layers, the upper and lower layers of the iron material to be charged have the same grain size composition. As shown by the broken line a in the graph, the CO concentration in the reducing gas in the lower layer portion of the iron raw material layer was from 30.0% to 12.
The change is relatively large to about 5%, and as much C
O is used for the reduction of the iron raw material, but in the upper part of the iron raw material layer, the CO concentration in the reducing gas is relatively small, from about 12.5% to about 12%, and there is only a small amount of CO. Not used for the reduction of iron raw materials. Therefore,
As indicated by a broken line a in the graph showing the relationship between the iron raw material reduction rate and the height of the iron raw material layer, the reduction rate of the upper layer portion of the iron raw material layer is low.
【００１９】それに対し、鉄原料層の下層部に平均粒度
の大きな鉄原料を装入し、鉄原料層の上層部に平均粒度
の小さな鉄原料を装入すると、図１、図２のグラフの実
線ｂに示すように、下層部では従来の鉄原料の還元率を
維持しつつ、上層部では、平均粒度の小さな鉄原料の良
好な還元率が保持できる。さらに、鉄原料層の中層部か
ら上層部にかけて、還元鉄及び／またはスクラップを装
入すると、１０００℃以上の高温領域において、還元鉄
及び／またはスクラップが層の収縮を抑制し、層の通気
性を確保するため、鉄原料層の中層部から上層部の高温
還元性状が改善される。これに伴い、融着開始温度の上
昇、層の圧損の低下など、高温性状も改善される（図３
参照）。On the other hand, when an iron raw material having a large average grain size is charged in the lower layer of the iron raw material layer and an iron raw material having a small average grain size is charged in the upper layer of the iron raw material layer, the graphs of FIGS. 1 and 2 are obtained. As shown by the solid line b, the lower layer portion maintains the conventional reduction rate of the iron raw material, while the upper layer portion can maintain the favorable reduction rate of the iron raw material having a small average particle size. Furthermore, when reduced iron and / or scrap is charged from the middle layer portion to the upper layer portion of the iron raw material layer, the reduced iron and / or scrap suppresses the contraction of the layer in the high temperature region of 1000 ° C. or higher, and the air permeability of the layer is increased. In order to secure the above, the high temperature reducing property from the middle layer portion to the upper layer portion of the iron raw material layer is improved. Along with this, high temperature properties such as an increase in fusion start temperature and a decrease in layer pressure loss are also improved (FIG. 3).
reference).
【００２０】粒度の異なる２種類の鉄原料を混合する場
合、粒径比が大きくなると、混合層の空隙率が低下する
ため（図４参照）、層の空隙率を確保するためには、層
を構成する粒度範囲については、粒度の大きいものと小
さいものとの粒径差をつけないほうが好ましい。この現
象は粒度の異なる３種類以上の鉄原料を混合使用する場
合も同様である。したがって、鉄原料の粒度構成を区分
して、粒度範囲を狭くし、区分した層を複数層重ねるこ
とにより、通常の装入法に比べ、鉄原料の空隙率を高く
することが可能となる。また、層の高さ方向で粒度構成
の狭い層を重ね、平均粒度の差を小さくすることによ
り、高炉炉頂部から炉下部への降下過程で生じうる細粒
のパーコレーション（層の浸透現象）を回避することが
可能となる。そのため、炉下部に至っても、鉄原料層の
空隙部の低下を抑制でき、通気性を良好とすることが可
能である。When two kinds of iron raw materials having different particle sizes are mixed, the porosity of the mixed layer decreases as the particle size ratio increases (see FIG. 4). With regard to the particle size range constituting the above, it is preferable not to make a difference in particle size between a large particle size and a small particle size. This phenomenon is the same when three or more kinds of iron raw materials having different particle sizes are mixed and used. Therefore, it is possible to increase the porosity of the iron raw material by dividing the particle size composition of the iron raw material, narrowing the particle size range, and stacking a plurality of divided layers, as compared with the usual charging method. In addition, by stacking layers with a narrow grain size composition in the height direction of the layers and reducing the difference in average grain size, percolation of fine particles (layer infiltration phenomenon) that can occur during the process of descending from the top of the blast furnace to the bottom of the furnace is achieved. It is possible to avoid it. Therefore, even when reaching the lower part of the furnace, it is possible to suppress the decrease of the void portion of the iron raw material layer and improve the air permeability.
【００２１】１チャージ分の鉄原料は、２バッチ装入に
限らず、３バッチ装入でもよい。その場合、下層から上
層へ徐々に鉄原料の粒度構成が小さくなるようにした
り、上層側から所定数層を細粒焼結鉱層としてもよい。
２バッチ目（２Ｏ）の鉱石類の平均粒度を１バッチ目
（１Ｏ）の鉱石類の平均粒度より小さくする方法として
は、炉頂より鉱石類を装入する前に、事前に鉱石類を所
定粒度範囲に篩い分ける。The iron raw material for one charge is not limited to being charged in two batches and may be charged in three batches. In that case, the grain size composition of the iron raw material may be gradually reduced from the lower layer to the upper layer, or a predetermined number of layers from the upper layer side may be fine-grained sintered ore layers.
As a method of making the average particle size of the ore of the second batch (2O) smaller than the average particle size of the ore of the first batch (1O), the ore is specified in advance before charging the ore from the furnace top. Sieve into particle size range.
【００２２】鉄原料の粒度構成については、大きい順
に、１５ｍｍ以上５０ｍｍ以下、５ｍｍ以上１５ｍｍ未
満、そして１ｍｍ以上５ｍｍ未満、好ましくは３ｍｍ以
上５ｍｍ未満とし、３層に区分する。３層に区分けする
境界粒度を５ｍｍと１５ｍｍで区分した理由を以下に説
明する。５ｍｍについては細粒の上限粒度であり、通常
高炉操業では５ｍｍ未満の細粒焼結鉱の使用量を制限す
る目安と考えられている。１５ｍｍについては、５ｍｍ
以上からなる層上部に、１ｍｍ以上５ｍｍ未満の細粒焼
結鉱を装入する場合、１ｍｍ以上５ｍｍ未満の細粒が５
ｍｍ以上からなる下層部に浸透することを抑制する上限
粒度である。つまり、鉄原料の粒度構成を５ｍｍ以上１
５ｍｍ未満とすることにより、高炉下部への降下過程
で、１ｍｍ以上５ｍｍ未満の細粒との混合層の形成を抑
制できる。還元鉄及び／またはスクラップに関しても、
粒度別に篩分け、同程度の平均粒度の鉄原料と混合使用
することにより、各層の空隙率を確保できる。Regarding the grain size composition of the iron raw material, it is divided into three layers, in order of increasing size: 15 mm or more and 50 mm or less, 5 mm or more and less than 15 mm, and 1 mm or more and less than 5 mm, preferably 3 mm or more and less than 5 mm. The reason for dividing the boundary grain size into 3 layers into 5 mm and 15 mm will be described below. 5 mm is the upper limit grain size of fine grains, and is considered to be a standard for limiting the amount of fine grain sinter less than 5 mm used in normal blast furnace operation. 5mm for 15mm
When a fine-grained sinter having a diameter of 1 mm or more and less than 5 mm is charged in the upper part of the above layer, the number of fine particles having a diameter of 1 mm or more and less than 5 mm is 5
It is the upper limit particle size that suppresses penetration into the lower layer portion having a size of at least mm. That is, the grain size composition of the iron raw material is 5 mm or more 1
By making it less than 5 mm, formation of a mixed layer with fine particles of 1 mm or more and less than 5 mm can be suppressed in the descending process to the lower part of the blast furnace. Regarding reduced iron and / or scrap,
The porosity of each layer can be secured by sieving according to particle size and mixing with an iron raw material having an average particle size of about the same.
【００２３】つぎに、細粒焼結鉱の装入方法と適正使用
量が全装入鉱石量の５〜２５ｗｔ％であることを説明す
る。高炉への１〜５ｍｍの細粒焼結鉱の装入に関して
は、従来技術の装入法では、細粒焼結鉱が粒径の大きい
コークス層および細粒鉱石層の空隙に入り込み混合層を
形成し、層の空隙率を低下させるため、通気抵抗を増大
させる。しかし、コークス層または粗粒鉱石層と混合す
ることなく細粒焼結鉱だけから構成される層にすること
により、空隙率を混合層の場合よりも確保することがで
き、通気抵抗を混合層の場合よりも小さくすることがで
きる。Next, the charging method of the fine-grained sintered ore and the proper usage amount will be described as being 5 to 25 wt% of the total amount of the ore charged. Regarding the charging of 1 to 5 mm fine-grained sintered ore into the blast furnace, in the conventional charging method, the fine-grained sintered ore enters the voids of the coke layer and the fine-grained ore layer having a large grain size and forms a mixed layer. As it forms, it reduces the porosity of the layer and thus increases the ventilation resistance. However, by forming a layer composed of only fine-grained sintered ore without mixing with the coke layer or coarse-grained ore layer, the porosity can be secured more than in the case of the mixed layer, and the ventilation resistance can be improved. Can be smaller than
【００２４】通常高炉に装入するコークスのサイズは２
５〜７５ｍｍであり、かさ密度は約０．５ｔ／ｍ3 であ
る。細粒焼結鉱のサイズは１〜５ｍｍであり、かさ密度
は約２ｔ／ｍ3 であるため、炉頂ホッパー中で細粒焼結
鉱を１Ｃ（コークスと鉱石装入の１サイクルの最初のコ
ークス装入）に混合すると、１Ｃ装入時に、粒径・密度
の差により細粒焼結鉱はホッパー下部に、コークスはホ
ッパー上部に自然に分級される。装入中、細粒焼結鉱は
粒径の大きいコークス層中を浸透し、さらに下方に移動
するが、その下層にある鉱石（サイズは５〜５０ｍｍ、
好ましくは５〜１５ｍｍ）層を浸透することができず、
この上に留まり細粒焼結層を形成する。この細粒焼結層
は細粒焼結鉱単独の層であるため空隙率は低下せず、通
気を良好に保つことができる。そして２Ｃ（複数バッチ
装入において２回目のコークス）以降の装入に際し、細
粒焼結鉱層の上を１Ｃ層が覆っているため、細粒焼結鉱
の堆積位置を変化させることがない。The size of the coke usually charged into the blast furnace is 2
It is 5 to 75 mm and the bulk density is about 0.5 t / m 3 . Since the size of the fine-grained sinter is 1 to 5 mm and the bulk density is about 2 t / m 3 , 1 C of the fine-grained sinter in the furnace top hopper (the first cycle of the coke and ore charging) When mixed in coke), the fine-grained sinter is naturally classified in the lower part of the hopper and the coke is classified in the upper part of the hopper due to the difference in particle size and density when charging 1C. During the charging, the fine-grained sinter penetrates into the coke layer with a large grain size and moves further downward, but the ore in the lower layer (the size is 5 to 50 mm,
(Preferably 5 to 15 mm) cannot penetrate the layer,
It stays on this and a fine-grained sintered layer is formed. Since this fine-grained sintered layer is a layer of fine-grained sintered ore alone, the porosity does not decrease, and good ventilation can be maintained. In addition, at the time of charging after 2C (the second coke in the case of charging a plurality of batches), since the 1C layer covers the fine-grained sintered ore layer, the deposition position of the fine-grained sintered ore is not changed.
【００２５】このように、鉄原料層を２層とする場合で
も、細粒焼結鉱層を１Ｃと混合装入することにより、装
入後の状態は鉄原料層が３層の状態となっており、下層
部の鉄原料の粒度構成を１５ｍｍ以上５０ｍｍ以下、中
層部の鉄原料の粒度構成を５ｍｍ以上１５ｍｍ未満、上
層部の鉄原料の粒度構成を１ｍｍ以上５ｍｍ未満とした
鉄原料の装入が可能となった。As described above, even when the iron raw material layer is made into two layers, by mixing and charging the fine-grained sintered ore layer with 1C, the state after charging becomes the state of three iron raw material layers. The charging of the iron raw material is such that the grain size composition of the iron raw material in the lower layer is 15 mm or more and 50 mm or less, the grain composition of the iron raw material in the middle layer is 5 mm or more and less than 15 mm, and the grain size composition of the iron raw material in the upper layer is 1 mm or more and less than 5 mm. Became possible.
【００２６】細粒焼結鉱の装入量を全装入鉱石量の５〜
２５ｗｔ％に限定した理由は、２５ｗｔ％超の細粒焼結
鉱の装入により炉内の通気抵抗が急激に増大するためで
ある。ただし、細粒焼結鉱の装入量は全装入鉱石量の５
ｗｔ％以上であることが焼結鉱歩留まりを改善する効果
が大きいため好ましい。細粒焼結鉱の粒度を１ｍｍ以上
５ｍｍ未満とした理由は、１ｍｍ未満であると装入時に
吹き飛ばされる量が多くなり、５ｍｍ以上にすると粒度
差が大きくなり空隙率が低下するためである。なお、層
の通気性を考慮した場合、細粒焼結鉱の粒度は３ｍｍ以
上５ｍｍ未満がより好ましい。The amount of fine-grained ore charged is 5 to the total amount of ore charged.
The reason for limiting the content to 25 wt% is that the ventilation resistance in the furnace rapidly increases due to the charging of the fine-grained sintered ore of more than 25 wt%. However, the amount of fine-grained ore charged is 5 of the total amount of ore charged.
It is preferable that the content is at least wt% because the effect of improving the yield of the sinter is great. The reason for setting the particle size of the fine-grained sintered ore to 1 mm or more and less than 5 mm is that if it is less than 1 mm, the amount blown off during charging is large, and if it is 5 mm or more, the difference in particle size becomes large and the porosity decreases. In consideration of the air permeability of the layer, the particle size of the fine-grained sintered ore is more preferably 3 mm or more and less than 5 mm.
【００２７】つぎに、小塊コークスを鉄原料の粒度５ｍ
ｍ以上１５ｍｍ未満の原料と混合して装入することが有
効であることを説明する。小塊コークスについては、鉄
原料との混合使用が通常行われているが、鉄原料層全体
に混合して使用するよりも、鉄原料層の上層部にのみ、
混合して使用するほうが、表１に示すように、鉄原料層
の空隙率を高め、通気性を改善できる効果がある。ま
た、図１、図２の一点鎖線ｃに示すように、鉄原料層の
上層部の還元率を高め、より効率良く鉄原料層の還元率
を改善できる。これは、図１に見られるように、鉄原料
層の下層部での還元の進行により、還元ガス中のＣＯ濃
度が低下し、上層部の還元に悪影響を及ぼすところを、
小塊コークスの存在により鉄原料層の上層部のＣＯ濃度
を高める効果があることによる。Next, the small coke was fed with an iron raw material having a particle size of 5 m.
It will be explained that it is effective to mix and charge the raw material having a length of m or more and less than 15 mm. For small coke, it is usually mixed and used with an iron raw material, but rather than being mixed and used for the entire iron raw material layer, only in the upper layer portion of the iron raw material layer,
As shown in Table 1, the mixed use is effective in increasing the porosity of the iron raw material layer and improving the air permeability. Further, as shown by the one-dot chain line c in FIGS. 1 and 2, the reduction rate of the upper layer portion of the iron raw material layer can be increased, and the reduction rate of the iron raw material layer can be improved more efficiently. This is because, as seen in FIG. 1, the CO concentration in the reducing gas decreases due to the progress of reduction in the lower layer of the iron raw material layer, which adversely affects the reduction in the upper layer.
This is because the presence of small coke has the effect of increasing the CO concentration in the upper layer of the iron raw material layer.
【００２８】[0028]
【表１】 [Table 1]
【００２９】本発明では、１１Ｏの鉄原料層あるいは上
層部の鉄原料層に、平均粒度の小さい鉄原料を使用する
ことで、上層部の還元率を保持するように改善している
が、小塊コークスを混合することにより、その改善効果
は大となる。粒度３ｍｍ以上１５ｍｍ以下の小塊コーク
スの粒度制限については、粒度３ｍｍ未満は通気性に悪
影響を及ぼし、粒度１５ｍｍ超は粒度範囲を広げるた
め、上層部の鉄原料層の空隙率を低下させ、通気性を悪
化させる。小塊コークスの３ｍｍ以上１５ｍｍ以下の粒
度調整は、コークスの選別過程で、所定の網目で篩うこ
とによって、調整する。In the present invention, an iron raw material having a small average particle size is used for the iron raw material layer of 11O or the iron raw material layer of the upper layer portion, so that the reduction rate of the upper layer portion can be maintained. The improvement effect becomes great by mixing the lump coke. Regarding the particle size limitation of small coke having a particle size of 3 mm or more and 15 mm or less, a particle size of less than 3 mm adversely affects the air permeability, and a particle size of more than 15 mm widens the particle size range. Aggravates sex. The particle size of the small coke of 3 mm or more and 15 mm or less is adjusted by sieving with a predetermined mesh in the process of selecting the coke.
【００２９】これにより、装入された下層部の鉄原料は
従来通りの良好な還元が維持され、一方上層部の鉄原料
は還元性の良い平均粒度の小さい原料であり、また小塊
コークスの混合によりガス還元性を高めることが可能と
なるため、従来の通常の粒度構成のものに比べて鉄原料
の還元率が向上する。細粒鉱石を上記のように装入する
場合に鉄原料の上層部に還元鉄または／スクラップを装
入することにより焼結鉱の歩留の向上と、鉄原料上層部
の高温性状の改善ができる。As a result, the iron raw material in the lower layer portion charged is maintained in a good reduction as in the conventional case, while the iron raw material in the upper layer portion is a raw material having a good reducibility and a small average particle size, and a small lump of coke. Since it becomes possible to enhance the gas reducibility by mixing, the reduction rate of the iron raw material is improved as compared with the conventional normal grain size constitution. When charging fine-grained ore as described above, it is possible to improve the yield of the sinter ore and the high-temperature property of the iron raw material upper layer by loading reduced iron or scrap into the upper layer of the iron raw material. it can.
【００３０】[0030]
【実施例】以下実施例により本発明の特徴を具体的に説
明する。内容積５０００ｍ3 級の高炉を用いた時の操業
について、表１にその結果を示す。 ほぼ同じ出銑能力
のベルレス高炉とベル高炉があり、通常操業時には、コ
ークス２バッチ，鉱石２バッチを１サイクルとする装入
（１Ｃ−２Ｃ−１Ｏ−２Ｏ：１Ｃ，２Ｃは１回目、２回
目のコークス装入、１Ｏ，２Ｏは１回目、２回目の鉱石
装入）において、細粒焼結鉱を２Ｏに混合して１Ｏ上に
全装入鉱石量の７．０ｗｔ％装入しているが、通気抵抗
指数は１．８９であり、安定操業を行っている。この装
入方法では、細粒焼結鉱装入量を全装入鉱石量の８．５
ｗｔ％以上にすると、１０，０００ｔ／ｄ以上の出銑量
を出すことが困難になる。ここで、１Ｏに対し２Ｏの鉄
原料の平均粒度を小さくし、かつ粒度構成を狭め、さら
に小塊コークス、スクラップの装入方法を変更し、細粒
焼結鉱の装入量を増大した場合に、本発明による方法と
従来の方法を比較し以下に示す。従来法では小塊コーク
ス、スクラップは鉱石層全体に混合して装入している。
小塊コークスは３〜１５ｍｍの粒度で、その使用量は３
０ｋｇ／ｔ−ｐｉｇであり、スクラップは粒度３ｍｍ以
上２０ｍｍ以下の良質のシュレッダー屑を３０ｋｇ／ｔ
−ｐｉｇを使用している。小塊コークスならびにスクラ
ップは通常操業時と同じ重量比である。EXAMPLES The features of the present invention will be specifically described with reference to the following examples. Table 1 shows the results of the operation using a blast furnace having an internal volume of 5000 m 3 class. There are bellless blast furnace and bell blast furnace with almost the same tapping capacity, and during normal operation, charging with 2 batches of coke and 2 batches of ore as one cycle (1C-2C-1O-2O: 1C, 2C is the first and second Coke charging, 1O, 2O is the first or second charging of ore), and fine-grained sintered ore is mixed with 2O, and 7.0 wt% of the total charging ore amount is charged on 1O. However, the ventilation resistance index is 1.89, indicating stable operation. In this charging method, the amount of fine-grained sintered ore charged is 8.5 times the total amount of ore charged.
If it is more than wt%, it will be difficult to produce a pig iron output of 10,000 t / d or more. Here, when the average grain size of the iron raw material of 20 is smaller than that of 1O, the grain size composition is narrowed, the charging method of small coke and scrap is changed, and the charging amount of fine-grained sintered ore is increased. The following is a comparison between the method according to the present invention and the conventional method. In the conventional method, small coke and scrap are mixed and charged into the entire ore layer.
Small coke has a particle size of 3 to 15 mm and its usage is 3
0 kg / t-pig, and scrap is 30 kg / t of high-quality shredder waste with a grain size of 3 mm or more and 20 mm or less.
You are using -pig. Small coke and scrap have the same weight ratio as in normal operation.
【００３１】[0031]
【表２】 [Table 2]
【００３２】実施例１は、ベルレス式高炉で１Ｃのコー
クスに１ｍｍ以上５ｍｍ未満の細粒焼結鉱を１０ｗｔ％
装入する場合である。このとき、２Ｏの鉄原料の平均粒
度より小さくする方法として、篩を設け、１５ｍｍ，５
ｍｍ，１ｍｍで分級した。粒度１５ｍｍ以上の鉱石を１
Ｏとして、粒度５ｍｍ以上１５ｍｍ未満の鉱石を２Ｏと
して装入した。また１ｍｍ以上５ｍｍ未満の細粒焼結鉱
は１Ｃと混合して装入した。細粒焼結層は粒径・密度の
差により細粒焼結鉱とコークスは自然に分級されコーク
ス層を浸透するが、コークス層の下にある粗粒鉱石層を
細粒焼結鉱は浸透できないため、細粒焼結鉱はコークス
層下部に局在化する。つまり、１Ｃに細粒焼結鉱を混合
して装入した結果、１Ｃ装入後はコークス上層にコーク
ス単味層がコークス下層にほぼ細粒焼結鉱だけの層が形
成される。このため、上部のコークス単味層の存在によ
り、下部の細粒焼結鉱層はこれ以降の装入に対し乱され
ることが無く、細粒焼結鉱の中心部への流れ込みや円周
方向のバランス崩れなどの問題も回避することができ
た。Example 1 is a bellless blast furnace in which 10 wt% of fine grain sinter of 1 mm or more and less than 5 mm is added to 1 C coke.
This is the case when charging. At this time, as a method for making the particle size smaller than the average particle size of the 2O iron raw material, a sieve is provided and
mm and 1 mm were used for classification. One ore with a grain size of 15 mm or more
As O, 20 ore having a grain size of 5 mm or more and less than 15 mm was charged. The fine-grained sintered ore having a size of 1 mm or more and less than 5 mm was mixed with 1C and charged. In the fine-grained sintered layer, the fine-grained sintered ore and coke are naturally classified due to the difference in particle size and density, and penetrate the coke layer, but the coarse-grained ore layer below the coke layer penetrates the fine-grained sintered ore. Since it is not possible, fine-grained sintered ore is localized in the lower part of the coke layer. That is, as a result of mixing and charging 1C with fine-grained sinter, a layer of coke single layer is formed on the upper layer of coke and a layer of almost only fine-grained sinter is formed on the lower layer of coke after charging 1C. For this reason, the presence of the coke monolayer in the upper part does not disturb the lower fine-grained sinter layer during the subsequent charging, and the fine-grained sinter flows into the central part or in the circumferential direction. I was able to avoid problems such as the imbalance of the.
【００３３】シュレッダー屑３０ｋｇ／ｔの全量を２Ｏ
に混合して装入する方法（Ａ法）と、シュレッダー屑３
０ｋｇ／ｔのうち、５ｋｇ／ｔ−ｐｉｇに相当する３ｍ
ｍ以上５ｍｍ未満の細粒シュレッダー屑と、２５ｋｇ／
ｔ−ｐｉｇに相当する５ｍｍ以上２０ｍｍ以下のシュレ
ッダー屑に分別し、５ｍｍ以上２０ｍｍ以下のシュレツ
ダー屑については２Ｏに、３ｍｍ以上５ｍｍ未満の細粒
シュレッダー屑については１Ｃに混合して装入する方法
（Ｂ法）を実施した。１Ｃに細粒焼結鉱を混合装入した
操業で、Ａ法の操業の場合、炉内の通気抵抗指数は１．
９５であり、操業に何等支障は無かった。また、Ｂ法の
装入法を採用すると、Ａ法に比べ、さらに炉内の通気抵
抗指数１．９２に低下し、操業はさらに改善された。The total amount of shredder scrap 30 kg / t is set to 20
The method of mixing and charging in (A method) and shredder waste 3
3m corresponding to 5kg / t-pig out of 0kg / t
Fine grain shredder waste of m or more and less than 5 mm and 25 kg /
A method of separating into 5 mm or more and 20 mm or less shredder scraps corresponding to t-pig, and mixing with 5O for shredder scraps of 5 mm or more and 20 mm or less and 1C for fine grain shredder scraps of 3 mm or more and less than 5 mm ( Method B) was carried out. In the operation in which the fine-grained sintered ore is mixed and charged in 1C and the operation of the method A is performed, the ventilation resistance index in the furnace is 1.
It was 95, and there was no hindrance to the operation. Further, when the charging method of the method B was adopted, the ventilation resistance index in the furnace was further lowered to 1.92, and the operation was further improved, as compared with the method A.
【００３４】実施例２は、ベル式高炉で１Ｃのコークス
に、細粒スクラップに加え、粒径３ｍｍ以上５ｍｍ未満
の細粒焼結鉱を全装入鉱石量の１９．０ｗｔ％装入する
場合である。細粒スクラップならびに細粒焼結鉱の装入
後の堆積状況については、実施例１と同様であり、コー
クス層の下端部に集積していた。炉内の通気抵抗指数は
２．１０であり、操業に支障は無かった。また、粗粒鉱
石と混合しないため、細粒焼結鉱の使用量を通常の７．
０ｗｔ％から１９．０ｗｔ％に増大しても還元率の低下
はみられていない。Example 2 is a case in which a bell-type blast furnace is used to charge 1 C coke with fine grain scrap and fine grain sinter having a grain size of 3 mm or more and less than 5 mm in an amount of 19.0 wt% of the total amount of ore. Is. The state of deposition of the fine-grain scrap and the fine-grain sinter after charging was the same as in Example 1, and accumulated at the lower end of the coke layer. The ventilation resistance index in the furnace was 2.10, and there was no hindrance to the operation. Also, since it is not mixed with coarse-grained ore, the amount of fine-grained ore used is usually 7.
No reduction in reduction rate was observed even if the amount was increased from 0 wt% to 19.0 wt%.
【００３５】実施例３は、実施例１のＡ法の操業中に、
鉄原料層全体に装入していた３〜１５ｍｍの粒度の小塊
コークスを、粒度５〜１５ｍｍの鉱石からなる２Ｏにの
み、混合使用した例である。細粒スクラップならびに細
粒焼結鉱の装入後の堆積状況については、実施例１と同
様であり、コークス層の下端部に集積していた。炉内の
通気抵抗指数は１．９５から１．９２に低下し、かつ操
業は改善され、燃料比も低減した。In Example 3, during the operation of Method A of Example 1,
This is an example in which the small coke having a particle size of 3 to 15 mm, which has been charged into the entire iron raw material layer, is mixed and used only with 20 made of ore having a particle size of 5 to 15 mm. The state of deposition of the fine-grain scrap and the fine-grain sinter after charging was the same as in Example 1, and accumulated at the lower end of the coke layer. The ventilation resistance index in the furnace dropped from 1.95 to 1.92, and the operation was improved and the fuel ratio was also reduced.
【００３６】比較例１は、粒径１ｍｍ以上５ｍｍ未満の
細粒焼結鉱を２Ｏに混合する通常操業と同じ方法で、細
粒焼結鉱を全装入鉱石量の１０．０ｗｔ％を装入する場
合である。このとき、次チャージの１Ｃ装入の際に鉱石
層の一部が崩され、炉中心部に細粒焼結鉱の流れ込みが
発生し、中心ガス流の確保が困難となり通気抵抗指数が
２．３０まで上昇し炉況が不安定となった。また、鉱石
層中の空隙率が低下したため還元率が低下し、炉腹温度
が低下した。さらに、比較例２は、粒径３ｍｍ以上５ｍ
ｍ未満の細粒焼結鉱をコークス層上に全鉱石装入量の１
９．０ｗｔ％装入する場合である。この場合も、通気抵
抗指数が２．３７まで上昇し、以降細粒焼結鉱の装入を
停止せざるを得なかった。In Comparative Example 1, the fine-grained sintered ore was charged in an amount of 10.0 wt% of the total amount of the ore by the same method as the ordinary operation of mixing fine-grained sintered ore having a grain size of 1 mm or more and less than 5 mm with 2O. It is when entering. At this time, a part of the ore layer is destroyed at the time of charging 1C of the next charge, a fine-grained sinter flows into the center of the furnace, and it becomes difficult to secure the central gas flow, and the ventilation resistance index becomes 2. The temperature rose to 30 and the furnace condition became unstable. In addition, the porosity in the ore layer was reduced, so the reduction rate was reduced, and the furnace side temperature was reduced. Furthermore, Comparative Example 2 has a particle size of 3 mm or more and 5 m.
Fine-grained sinter less than m in total amount of ore charged on coke bed is 1
This is the case when charging 9.0 wt%. Also in this case, the ventilation resistance index increased to 2.37, and the charging of the fine-grained sintered ore had to be stopped thereafter.
【００３７】[0037]
【発明の効果】本発明により、鉄原料層の高温性状を改
善するための還元鉄、スクラップあるいは小塊コークス
の使用法を提供し、また新しい細粒焼結鉱の装入方法を
適用することにより、細粒焼結鉱の炉中心部への流れ込
みや炉内の通気抵抗の増大が抑制できる。さらには鉱石
層の還元率を向上でき、融着帯部の通気抵抗を低下させ
ることができるため、高出銑比を維持しながら高炉での
細粒焼結鉱の多量使用が可能である。これにより、焼結
鉱の歩留まりを約８〜１１％向上することができた。According to the present invention, there is provided a method of using reduced iron, scrap or small coke for improving the high temperature properties of an iron raw material layer, and a new method for charging fine-grained sintered ore is applied. As a result, it is possible to suppress the inflow of fine-grained sintered ore into the central portion of the furnace and the increase of ventilation resistance in the furnace. Furthermore, since the reduction rate of the ore layer can be improved and the ventilation resistance of the cohesive zone can be reduced, it is possible to use a large amount of fine-grained sintered ore in the blast furnace while maintaining a high tap ratio. As a result, the yield of the sintered ore could be improved by about 8 to 11%.
【図１】還元ガス中のＣＯ濃度と、鉄原料層の高さとの
関係を示す図。FIG. 1 is a diagram showing the relationship between the CO concentration in a reducing gas and the height of an iron raw material layer.
【図２】鉄原料還元率と、鉄原料層の高さとの関係を示
す図。FIG. 2 is a diagram showing a relationship between an iron raw material reduction rate and the height of an iron raw material layer.
【図３】鉄原料層の上層部にスクラップを装入した場合
と装入しない場合の高温性状を比較した図。FIG. 3 is a diagram comparing high-temperature properties when scrap is charged in the upper part of the iron raw material layer and when it is not charged.
【図４】粒度の異なる２種類の鉄原料の粒径比、混合比
と空隙率の関係を示す図。FIG. 4 is a diagram showing a relationship between a particle size ratio and a mixing ratio of two types of iron raw materials having different particle sizes and a porosity.
フロントページの続き (72)発明者 塩田 哲也 大分県大分市大字西ノ洲１番地 新日本製 鐵株式会社大分製鐵所内Front page continuation (72) Inventor Tetsuya Shioda 1 Nishinosu, Oita City, Oita Prefecture New Nippon Steel Co., Ltd. Oita Works
Claims (5)
続装入して鉄原料層を形成した後、コークスを１バッチ
以上連続装入してコークス層を形成することを１サイク
ルとする高炉の原料装入方法において、還元鉄及び／ま
たはスクラップを鉄原料層の中層部および／または上層
部に装入することを特徴とする高炉の原料装入方法。1. A cycle comprising continuously charging one or more batches of iron raw material from the furnace top of a blast furnace to form an iron raw material layer and then continuously charging one or more batches of coke to form a coke layer. A method of charging a raw material for a blast furnace, comprising charging reduced iron and / or scrap to an intermediate layer portion and / or an upper layer portion of an iron raw material layer in the raw material charging method for the blast furnace.
続装入して鉄原料層を形成した後、コークスを１バッチ
以上連続装入してコークス層を形成する高炉の原料装入
方法において、前記鉄原料を篩分けし、平均粒度の大き
い順に複数バッチで装入して、平均粒度の異なる複数の
層とし、鉄原料層の上層部に、還元鉄及び／またはスク
ラップを装入することを特徴とする高炉の原料装入方
法。2. A method for charging a raw material for a blast furnace, comprising continuously charging one or more batches of iron raw material from the top of the blast furnace to form an iron raw material layer and then continuously charging one or more batches of coke to form a coke layer. In above, the iron raw material is sieved and charged in a plurality of batches in the order of large average particle size to form a plurality of layers having different average particle sizes, and reduced iron and / or scrap is charged in the upper layer part of the iron raw material layer. A method for charging a raw material for a blast furnace, which is characterized in that
した後に、コークスを２バッチで装入することを１サイ
クルとする高炉の原料装入方法において、鉄原料の１回
目のバッチの粒度構成を１５ｍｍ以上５０ｍｍ以下とし
て鉄原料の下層部を形成し、鉄原料の２回目のバッチの
粒度構成を５ｍｍ以上１５ｍｍ未満として鉄原料の上層
部を形成し、装入鉄原料の５〜２５ｗｔ％を１ｍｍ以上
５ｍｍ未満の細粒鉄原料として１回目のコークス装入バ
ッチに混合した後、前記鉄原料の上層部の上に装入する
ことを特徴とする高炉の原料装入方法。3. A method for charging a raw material of a blast furnace, comprising charging the iron raw material from the top of the blast furnace in two batches and then charging the coke in two batches, the first batch of the iron raw material. To form the lower layer part of the iron raw material with a grain size composition of 15 mm or more and 50 mm or less, and to form the upper layer part of the iron raw material with a grain size composition of the second batch of the iron raw material of 5 mm or more and less than 15 mm. A raw material charging method for a blast furnace, which comprises mixing 25 wt% as a fine iron raw material having a size of 1 mm or more and less than 5 mm into a first coke charging batch, and then charging the iron raw material above the upper layer portion.
ｍ以上１５ｍｍ未満の鉄原料に、粒度３ｍｍ以上１５ｍ
ｍ以下の小塊コークスを混合した後、装入して鉄原料の
上層部を形成することを特徴とする請求項３記載の高炉
の操業方法。4. The particle size of the second charging batch of iron raw material is 5 m.
For iron raw material of m or more and less than 15 mm, grain size of 3 mm or more and 15 m
The method for operating a blast furnace according to claim 3, wherein after mixing the small coke of m or less, it is charged to form the upper layer portion of the iron raw material.
入方法において、鉄原料層の上層部に還元鉄及び／また
はスクラップを装入することを特徴とする高炉の原料装
入方法。5. The blast furnace raw material charging method according to claim 3 or 4, wherein reduced iron and / or scrap is charged in an upper layer of the iron raw material layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14694295A JP3247276B2 (en) | 1995-01-06 | 1995-05-23 | Blast furnace charging method |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1558595 | 1995-01-06 | ||
| JP7-15585 | 1995-01-06 | ||
| JP14694295A JP3247276B2 (en) | 1995-01-06 | 1995-05-23 | Blast furnace charging method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08239704A true JPH08239704A (en) | 1996-09-17 |
| JP3247276B2 JP3247276B2 (en) | 2002-01-15 |
Family
ID=26351762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14694295A Expired - Lifetime JP3247276B2 (en) | 1995-01-06 | 1995-05-23 | Blast furnace charging method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3247276B2 (en) |
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|---|---|---|---|---|
| JP2006028594A (en) * | 2004-07-16 | 2006-02-02 | Jfe Steel Kk | Method for operating blast furnace |
| JP2010106333A (en) * | 2008-10-31 | 2010-05-13 | Jfe Steel Corp | Method for charging raw material into bell-less blast furnace |
| JP2010133008A (en) * | 2008-10-31 | 2010-06-17 | Jfe Steel Corp | Method for charging raw material into bell-less blast furnace |
| JP2010150646A (en) * | 2008-12-26 | 2010-07-08 | Jfe Steel Corp | Method for charging raw material into blast furnace |
| JP2013256696A (en) * | 2012-06-13 | 2013-12-26 | Nippon Steel & Sumitomo Metal Corp | Method for operating blast furnace |
| CN104152614A (en) * | 2014-08-26 | 2014-11-19 | 攀钢集团西昌钢钒有限公司 | Distribution method of blast furnace burdens |
| WO2024090727A1 (en) * | 2022-10-28 | 2024-05-02 | 현대제철 주식회사 | Hot rolled steel sheet, part for vehicle, and method for manufacturing same |
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1995
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|---|---|---|---|---|
| JP2006028594A (en) * | 2004-07-16 | 2006-02-02 | Jfe Steel Kk | Method for operating blast furnace |
| JP4556525B2 (en) * | 2004-07-16 | 2010-10-06 | Ｊｆｅスチール株式会社 | Blast furnace operation method |
| JP2010106333A (en) * | 2008-10-31 | 2010-05-13 | Jfe Steel Corp | Method for charging raw material into bell-less blast furnace |
| JP2010133008A (en) * | 2008-10-31 | 2010-06-17 | Jfe Steel Corp | Method for charging raw material into bell-less blast furnace |
| JP2010150646A (en) * | 2008-12-26 | 2010-07-08 | Jfe Steel Corp | Method for charging raw material into blast furnace |
| JP2013256696A (en) * | 2012-06-13 | 2013-12-26 | Nippon Steel & Sumitomo Metal Corp | Method for operating blast furnace |
| CN104152614A (en) * | 2014-08-26 | 2014-11-19 | 攀钢集团西昌钢钒有限公司 | Distribution method of blast furnace burdens |
| CN104152614B (en) * | 2014-08-26 | 2016-06-01 | 攀钢集团西昌钢钒有限公司 | The distributing process of blast furnace burden |
| WO2024090727A1 (en) * | 2022-10-28 | 2024-05-02 | 현대제철 주식회사 | Hot rolled steel sheet, part for vehicle, and method for manufacturing same |
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