JPH09143523A - Method for melting iron scrap at high speed - Google Patents

Method for melting iron scrap at high speed

Info

Publication number
JPH09143523A
JPH09143523A JP30700795A JP30700795A JPH09143523A JP H09143523 A JPH09143523 A JP H09143523A JP 30700795 A JP30700795 A JP 30700795A JP 30700795 A JP30700795 A JP 30700795A JP H09143523 A JPH09143523 A JP H09143523A
Authority
JP
Japan
Prior art keywords
furnace
scrap
melting furnace
melting
exhaust gas
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Withdrawn
Application number
JP30700795A
Other languages
Japanese (ja)
Inventor
Mitsutaka Matsuo
充高 松尾
Hiroyuki Katayama
裕之 片山
Hiroyuki Kajioka
博幸 梶岡
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Nippon Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Priority to JP30700795A priority Critical patent/JPH09143523A/en
Publication of JPH09143523A publication Critical patent/JPH09143523A/en
Withdrawn legal-status Critical Current

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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

Abstract

PROBLEM TO BE SOLVED: To provide a preheating and melting method of iron scrap which improves the secondary combustion ratio in a melting furnace and effectively utilizes the sensible heat of exhaust gas of the melting furnace to preheat the raw material scrap and can supply gaseous oxygen at high speed same as or quicker than the ordinary converter method, and the preheating method of the scrap which does not circulate and concentrate zinc content. SOLUTION: The melting furnace 1 for melting the iron scrap by blowing the gaseous oxygen to burn the carbonaceous material and generate the heat, is connected with a vertical type packing layer furnace 7 for executing the preheating of the raw material iron scrap charged into the melting furnace by introducing the high temp. exhaust gas generated in the melting furnace. Atmosphere pressure P (10<2> kPa) in the melting furnace is adjusted so as to satisfy the relation, P>=0.005(F/V)+1.0, concerning the inner vol. V (m<3> ) in the melting furnace and the supplying speed F (Nm<3> /h) of the gaseous oxygen, and desirably, the exhaust gas temp. at the outlet side of the vertical type packing layer furnace 7 is adjusted to >=600 deg.C.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、鉄スクラップ(以
下単にスクラップという)を電力を用いず炭材の燃焼熱
により熱効率よくかつ高速度で溶解する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting iron scrap (hereinafter simply referred to as "scrap") by heat of combustion of carbonaceous material at a high thermal efficiency and at high speed without using electric power.

【０００２】[0002]

【従来の技術】スクラップは通常電気炉で溶解される
が、わが国では電力コストが大きいため一般的には経済
的でない。とくに電力の需給バランスから、昼間の電力
単価が夜間の電力単価より大巾に高く設定されるケ−ス
が多く、夜間のみ電気炉の操業が行われる場合も少なく
ないため、電気炉設備の稼働率が低く、生産性が十分で
ないという問題がある。2. Description of the Related Art Scrap is usually melted in an electric furnace, but it is generally uneconomical in Japan due to the high power cost. In particular, due to the balance of supply and demand of electric power, in many cases the unit price of electricity during the day is set to be much higher than the unit price of electricity at night, and there are many cases where the electric furnace is operated only at night. There is a problem that the rate is low and the productivity is not sufficient.

【０００３】近年わが国においても、スクラップの発生
量が著しく増加し、鉄鋼生産のうちスクラップを原料と
するものの比率が増加してきており、より経済的で生産
性の高い溶解方法の開発が望まれている。In Japan in recent years, the amount of scraps generated has increased remarkably, and the ratio of those made from scraps in steel production has increased, and it is desired to develop a more economical and highly productive melting method. There is.

【０００４】電気エネルギ−によらないでスクラップを
溶解する方法として、例えば転炉型の反応容器で、容器
内の鉄浴の内部又は上部に炭材及び酸素ガスを供給し、
酸素ガスによる炭材の燃焼熱でスクラップを溶解する方
法が試みられている。この溶解方法においては、反応容
器内の少量の鉄浴に上方からスクラップを逐次供給して
溶解し、鉄浴が所定の量になってから出湯するが、出湯
の際に一部の溶鉄を炉内に残留させる、いわゆる残し湯
式がとられることが多い。As a method of melting scrap without using electric energy, for example, in a converter-type reaction vessel, carbonaceous material and oxygen gas are supplied to the inside or the top of an iron bath in the vessel,
Attempts have been made to dissolve scraps by the heat of combustion of carbonaceous materials by oxygen gas. In this melting method, scrap is sequentially supplied to a small amount of iron bath in the reaction vessel from above to melt, and the molten iron is tapped after the iron bath reaches a predetermined amount. In many cases, a so-called residual hot water system is used in which the liquid is left inside.

【０００５】このような炭材の燃焼エネルギ−によっ
て、スクラップを溶解する方法においては、経済性を高
める上で以下のような課題がある。 溶解炉の二次燃焼率(排ガスの((%CO2)/((%CO)+(%C
O2))×100(%))を高めること 高温の溶解炉排ガスの顕熱をスクラップの予熱等に有
効の利用すること 生産性を高めるために、溶解炉の内容積をＶ(ｍ3)、
酸素ガスの供給速度をＦ(Ｎｍ3／ｈ)として、単位内容
積当たりの酸素ガスの供給速度Ｆ／Ｖの値を大きくする
こと。例えば、現行転炉製鋼方でのＦ／Ｖの値（おおむ
ね１００〜５００の範囲）より大きくすることが望まし
い。In the method of melting scrap by the combustion energy of such carbonaceous material, there are the following problems in order to improve the economical efficiency. Secondary burning rate of melting furnace (((% CO 2 ) / ((% CO) + (% C
O 2 )) × 100 (%)) is increased. Effective use of sensible heat of high-temperature melting furnace exhaust gas for scrap preheating, etc. In order to improve productivity, the internal volume of the melting furnace is set to V (m 3 ). ,
The supply rate of oxygen gas is F (Nm 3 / h), and the value of the supply rate F / V of oxygen gas per unit internal volume is increased. For example, it is desirable to make it larger than the F / V value (generally in the range of 100 to 500) in the existing converter steelmaking method.

【０００６】スクラップ溶解炉で二次燃焼率を高める方
法としては、例えば特開平２−１４１５１１号公報に開
示されているように、鉄浴の上部に所定量(例えば溶鉄
トン当り３５０kg)以上の溶融スラグを置き、溶融スラ
グ層内に炭材を懸濁させて、上吹き酸素ガスで燃焼させ
る方法がある。As a method for increasing the secondary combustion rate in a scrap melting furnace, for example, as disclosed in Japanese Patent Laid-Open No. 2-141511, a predetermined amount (for example, 350 kg per ton of molten iron) of a certain amount or more is melted in the upper part of an iron bath. There is a method of placing slag, suspending carbonaceous material in the molten slag layer, and burning it with top-blown oxygen gas.

【０００７】しかし、この方法ではＦ／Ｖの値をある程
度以上に大きくすると、溶融スラグの粒滴や炭材及び炉
内で生成したダストが炉外に飛出し、歩留りが低下する
と共に、安定な操業が難しくなるという問題がある。ま
た、溶解炉排ガスの顕熱を有効に利用する方法として、
高温の排ガスを原料スクラップの装入されたバスケッ
ト、横型回転炉、縦型充填層炉等に導入して、スクラッ
プの予熱を行う方法が知られている。However, in this method, if the F / V value is increased to a certain level or more, the droplets of molten slag, the carbonaceous material, and the dust generated in the furnace fly out of the furnace, which lowers the yield and stabilizes it. There is a problem that operation becomes difficult. Further, as a method of effectively utilizing the sensible heat of the melting furnace exhaust gas,
A method is known in which high-temperature exhaust gas is introduced into a basket containing raw material scrap, a horizontal rotary furnace, a vertical packed bed furnace, or the like to preheat the scrap.

【０００８】しかし、この場合も、Ｆ／Ｖの値をある程
度以上に大きくすると、炉外に飛散した溶融スラグ、炭
材、ダスト等が予熱容器内のスクラップに付着し、スク
ラップ充填層内で偏流や目詰まりを起こし、安定な操業
が難しくなるという問題がある。However, also in this case, if the F / V value is increased to a certain extent or more, the molten slag, carbonaceous material, dust, etc. scattered outside the furnace adhere to the scrap in the preheating container, causing a drift in the scrap packed bed. There is a problem that it will cause clogging and clogging, making stable operation difficult.

【０００９】一方、市中で回収されるスクラップには、
亜鉛メッキされた缶、板が混入しており、かなりの量の
亜鉛分が含まれる。この亜鉛分は高温の溶解炉内で大部
分が気化し、排ガスに同伴されて炉外に逸失するが、ス
クラップ充填層の温度が低い場合にはスクラップに凝着
し、これが再び溶解炉に装入されて、亜鉛分の循環、濃
縮が起こるという問題があることが知られている。この
亜鉛分の循環、濃縮も鉄鋼製品の品質を低下させ、かつ
スクラップ予熱装置の安定な操業を困難にする重要な問
題である。On the other hand, for scraps collected in the city,
It is mixed with galvanized cans and plates and contains a significant amount of zinc. Most of this zinc content is vaporized in the high temperature melting furnace and is lost to the outside of the furnace along with the exhaust gas, but when the temperature of the scrap packed bed is low, it adheres to the scrap and this is reused in the melting furnace. It is known that there is a problem that zinc content is circulated and zinc content is circulated and concentrated. The circulation and concentration of this zinc component are also important problems that deteriorate the quality of steel products and make stable operation of the scrap preheating device difficult.

【００１０】[0010]

【発明が解決しようとする課題】本発明は、上記のよう
な従来技術の問題点を解決するためになされたものであ
って、その目的とするところは、鉄スクラップを溶解す
るに際し、炭材の燃焼エネルギ−を熱効率良く利用し、
かつ生産性が高い鉄スクラップの溶解方法を提供するこ
とにある。SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and the purpose thereof is to dissolve carbonaceous material when melting iron scrap. Utilizing the combustion energy of
Another object of the present invention is to provide a method for melting iron scrap with high productivity.

【００１１】とくに、二次燃焼率を高めて溶解炉内での
炭材の燃焼発熱量を増大させると共に、溶解炉排ガスの
顕熱を原料スクラップの予熱に有効に利用し、かつ現行
転炉法と同等以上のＦ／Ｖの値で酸素ガスを提供して
も、炉外へのスラグやダストの飛散ロスが少なく、安定
な操業の可能な鉄スクラップの溶解方法を提供すること
を目的とする。In particular, the secondary combustion rate is increased to increase the combustion calorific value of the carbonaceous material in the melting furnace, the sensible heat of the melting furnace exhaust gas is effectively used for preheating the raw material scrap, and the current converter method is used. It is an object of the present invention to provide a method for melting iron scrap that enables stable operation with little loss of slag and dust scattering outside the furnace even if oxygen gas is provided at a F / V value equal to or higher than .

【００１２】また、本発明の他の目的は、亜鉛分の循
環、濃縮の無いスクラップの予熱方法を提供することに
ある。Another object of the present invention is to provide a scrap preheating method without recycling or concentrating zinc content.

【００１３】[0013]

【課題を解決するための手段】本発明の発明者らは、上
記の課題を解決するため手段について、種々研究を重ね
た結果、転炉型反応容器内の鉄浴上部に、適切な状態に
フォ−ミングした溶融スラグ層を形成させ、その内部で
炭材を酸素ガスにより燃焼させれば、二次燃焼率を高め
ても耐火物の溶損を低減できることを知見した。Means for Solving the Problems The inventors of the present invention have conducted various studies on the means for solving the above-mentioned problems, and as a result, have found that the iron bath in the converter-type reaction vessel has an appropriate state in the upper part. It was found that the molten loss of refractory can be reduced even if the secondary combustion rate is increased by forming a molten slag layer that has been formed and burning the carbonaceous material therein with oxygen gas.

【００１４】また、フォ−ミングした溶融スラグ及び該
溶融スラグ中に浮遊する炭材は、酸素ガスの供給速度を
増大させる炉外に飛散しやすく、スクラップ予熱装置の
安定な操業を妨げるため、溶解炉内の雰囲気圧力を制御
するのが最も有効なことを知見した。Further, the formed molten slag and the carbonaceous material floating in the molten slag are likely to be scattered outside the furnace which increases the supply rate of oxygen gas, which hinders the stable operation of the scrap preheating device, so that it is melted. It was found that controlling the atmospheric pressure in the furnace is the most effective.

【００１５】本発明はこれらの知見に基づいてなされた
もので、その要旨とするところは、(1)酸素ガスを吹き
込んで炭材を燃焼発熱させて鉄スクラップを溶解する溶
解炉と、該溶解炉で発生する高温の排ガスを導入して溶
解炉に装入する原料鉄スクラップの予熱を行う縦型充填
層炉を連結し、溶解炉内の雰囲気圧力を、溶解炉の内容
積及び酸素ガスの供給速度に対して、下式の関係を満た
すように調節することを特徴とする鉄スクラップの高速
溶解法である。The present invention has been made on the basis of these findings. The gist of the invention is (1) a melting furnace for melting iron scrap by injecting oxygen gas to cause the carbon material to burn and generate heat, and the melting furnace. The vertical packed bed furnace that introduces the high-temperature exhaust gas generated in the furnace and preheats the raw material iron scrap to be charged into the melting furnace is connected, and the atmospheric pressure in the melting furnace is set to the internal volume of the melting furnace and the oxygen gas This is a high-speed melting method for iron scrap, which is characterized in that the supply rate is adjusted so as to satisfy the following equation.

【００１６】Ｐ ≧０．００５(Ｆ／Ｖ)＋１．０ Ｐ：溶解炉内の雰囲気圧力(１０2ｋＰａ） Ｆ：酸素ガスの供給速度(Ｎｍ3／ｈ) Ｖ：溶解炉の内容積(ｍ3) また、亜鉛分の循環、濃縮の無いスクラップの予熱方法
を提供するための手段として(2)原料鉄スクラップの予
熱を行う縦型充填層炉の出口のガス温度を６００℃以上
に保つことを特徴とする前項(1)記載の鉄スクラップの
高速溶解法である。P ≧ 0.005 (F / V) +1.0 P: Atmospheric pressure in the melting furnace (10 2 kPa) F: Oxygen gas supply rate (Nm 3 / h) V: Internal volume of the melting furnace ( m 3 ) Also, as a means for providing a preheating method for scrap without circulation and concentration of zinc content, (2) keep the gas temperature at the outlet of the vertical packed bed furnace for preheating raw material iron scrap at 600 ° C or higher. The high-speed melting method for iron scrap described in (1) above, which is characterized in that

【００１７】[0017]

【発明の実施の形態】図１に、本発明の鉄スクラップの
溶解方法を実施するための溶解装置の例を示す。溶解炉
炉体１は、耐火物６によって内張りされており、炉口シ
−ル装置４及び排ガスダクト５を介して、縦型充填層炉
７の接続されている。縦型充填層炉７の後流の排ガスダ
クトに設けられた図示していないダンパ−により、溶解
炉内及び縦型充填層炉７内の圧力が制御される。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a melting apparatus for carrying out the method for melting iron scrap of the present invention. The melting furnace body 1 is lined with a refractory material 6 and is connected to a vertical packed bed furnace 7 via a furnace opening seal device 4 and an exhaust gas duct 5. The pressure in the melting furnace and in the vertical packed bed furnace 7 is controlled by a damper (not shown) provided in the exhaust gas duct downstream of the vertical packed bed furnace 7.

【００１８】溶解炉内には鉄浴１０と溶融スラグ層１１
が形成されており、縦型充填層炉下部に設けられたスク
ラップ供給速度制御手段８により、所定の供給速度でス
クラップが炉内に供給される。炭材は炉上部の炭材供給
装置９から溶融スラグ層に供給される。酸素ガスは上吹
きランス２から溶融スラグ層及び鉄浴に吹き付けられ、
溶融スラグ層内に懸濁している炭材及び鉄浴中の炭素を
燃焼させる。この燃焼熱をスクラップの溶解に有効に利
用するため、底吹き羽口３から鉄浴１０内にガスを吹き
込んで炉内の溶融物を撹拌し、伝熱を促進させる。An iron bath 10 and a molten slag layer 11 are provided in the melting furnace.
Is formed, and scrap is supplied into the furnace at a predetermined supply speed by the scrap supply speed control means 8 provided in the lower part of the vertical packed bed furnace. The carbonaceous material is supplied to the molten slag layer from the carbonaceous material supply device 9 in the upper part of the furnace. Oxygen gas is blown from the top blowing lance 2 onto the molten slag layer and the iron bath,
The carbonaceous material suspended in the molten slag layer and the carbon in the iron bath are burned. In order to effectively use this combustion heat for melting scrap, gas is blown into the iron bath 10 from the bottom blowing tuyere 3 to stir the melt in the furnace to accelerate heat transfer.

【００１９】なお、本発明における酸素ガスとしては、
純酸素ガスの他に、少量の窒素等を含む粗酸素ガスや一
部空気等の非燃性のガスを含む酸素ガスを使用すること
ができるが、酸素の濃度が70%以上であることが望まし
い。As the oxygen gas in the present invention,
In addition to pure oxygen gas, it is possible to use crude oxygen gas containing a small amount of nitrogen etc. or oxygen gas containing non-combustible gas such as some air, but the oxygen concentration may be 70% or more. desirable.

【００２０】所定量の原料スクラップの溶解が終了した
ところで、貯溜された溶鉄が炉外に排出される。溶鉄の
排出は、炉底部の出湯孔１２を開口して行うことが望ま
しい。本発明において生成される溶鉄は溶銑及び溶鋼を
含む。When the melting of a predetermined amount of raw material scrap is completed, the stored molten iron is discharged to the outside of the furnace. Molten iron is preferably discharged by opening the tap hole 12 at the bottom of the furnace. The molten iron produced in the present invention includes molten pig iron and molten steel.

【００２１】本発明の溶解方法においては、スクラップ
の予熱に縦型充填層炉を使用するため、サイズの小さい
スクラップだけでなく、大形のスクラップも予熱できる
という利点がある。また、一般に他の形式の予熱装置よ
りも熱効率が良く、かつスクラップの予熱温度を高くで
きるという利点がある。In the melting method of the present invention, since the vertical packed bed furnace is used for preheating scrap, there is an advantage that not only small size scrap but also large size scrap can be preheated. In addition, there are advantages that thermal efficiency is generally higher than that of other types of preheating devices and that the preheating temperature of scrap can be increased.

【００２２】しかし、あまりスクラップの予熱温度を高
くすると、縦型充填層炉内でスクラップが融着するとい
う問題がある。したがって、ＣＯからＣＯ2までの燃焼
熱をなるべく溶解炉内で利用する必要があり、そのため
には、溶解炉の二次燃焼率を例えば４５〜９０％程度ま
で高めることが望ましい。However, if the preheating temperature of the scrap is raised too much, there is a problem that the scrap is fused in the vertical packed bed furnace. Therefore, it is necessary to utilize combustion heat from CO to CO 2 in the melting furnace as much as possible, and for that purpose, it is desirable to increase the secondary combustion rate of the melting furnace to, for example, about 45 to 90%.

【００２３】溶解炉内の二次燃焼率を高めかつ耐火物の
過熱を防止するには、炉内に安定なフォ−ミングスラグ
層を形成させ、その内部に懸濁した炭材を上吹き酸素ガ
スで燃焼させることが望ましい。しかし、この場合酸素
ジェットによりスラグの粒滴や粒径の小さい炭材が吹き
上げられ、上昇する排ガス気流に同伴されて、ダストと
して炉外に飛出し易い。現行の製鋼用転炉と同程度のＦ
／Ｖの値でも、ダスト量が著しく多くなるという問題が
ある。In order to increase the secondary combustion rate in the melting furnace and prevent overheating of the refractory material, a stable forming slag layer is formed in the furnace, and the carbonaceous material suspended in the layer is blown onto the oxygen gas. It is desirable to burn at. However, in this case, the oxygen jet blows up slag droplets and carbonaceous material having a small particle diameter, is entrained in the rising exhaust gas flow, and easily blows out of the furnace as dust. F as high as that of the existing steelmaking converter
Even with the value of / V, there is a problem in that the amount of dust is significantly increased.

【００２４】このようなダスト飛出しは、炭材や造滓剤
の歩留を低下させるだけでなく縦型充填層炉内のスクラ
ップに付着して、目詰まりや偏流、あるいは局所的なガ
スの吹き抜けを起こし、安定な操業を困難にさせる。こ
れを防止する方法としては、溶解炉内の雰囲気圧力を高
めて、酸素ジェットや上昇排ガス気流の流速を低減させ
るのが最も有効である。Such dust emission not only lowers the yield of carbonaceous materials and slag-forming agents, but also adheres to scrap in the vertical packed bed furnace to cause clogging, drift, or local gas generation. It causes blow through and makes stable operation difficult. The most effective way to prevent this is to increase the atmospheric pressure in the melting furnace to reduce the flow velocity of the oxygen jet and the rising exhaust gas flow.

【００２５】図２に、安定な操業が可能な溶解炉内の雰
囲気圧力ＰとＦ／Ｖの値の関係を示す。ダストの飛出量
はＦ／Ｖの値が大きくなると次第に多くなるが、安定な
操業を行うためには、Ｆ／Ｖの値が１００程度の場合は
Ｐが１．５×１０2ｋＰａ(絶対圧)又はそれ以上、Ｆ／
Ｖの値が３００程度の場合はＰが２．５×１０2ｋＰａ
又はそれ以上必要である。FIG. 2 shows the relationship between the atmospheric pressure P in the melting furnace and the value of F / V, which enables stable operation. The amount of dust flying out increases as the F / V value increases, but in order to perform stable operation, P is 1.5 × 10 2 kPa (absolute when the F / V value is about 100). Pressure) or higher, F /
When the value of V is about 300, P is 2.5 × 10 2 kPa
Or more is needed.

【００２６】したがって、本発明の溶解方法を実施する
には、図２内の直線で示すように、溶解炉内の雰囲気圧
力Ｐ(１０2ｋＰａ）を下式の範囲に調整する必要があ
る。 Ｐ ≧０．００５(Ｆ／Ｖ)＋1.０ 溶解炉内の雰囲気圧力を高くすることにより、溶解炉に
連結された縦型充填層炉内の雰囲気圧力も容易に高くす
ることができる。したがって、縦型充填層炉内の排ガス
の流速も小さくなり、偏流や局所的な吹き抜けが起こり
にくくなると共に、スクラップ予熱の熱効率も向上す
る。Therefore, in order to carry out the melting method of the present invention, it is necessary to adjust the atmospheric pressure P (10 2 kPa) in the melting furnace within the range of the following equation, as shown by the straight line in FIG. P ≧ 0.005 (F / V) +1.0 By increasing the atmospheric pressure in the melting furnace, the atmospheric pressure in the vertical packed bed furnace connected to the melting furnace can be easily increased. Therefore, the flow velocity of the exhaust gas in the vertical packed bed furnace is also reduced, uneven flow and local blow-through are less likely to occur, and the thermal efficiency of scrap preheating is improved.

【００２７】一方、亜鉛メッキされた缶、板等亜鉛分が
混入しているスクラップを原料として溶解する場合、亜
鉛の大部分が高温の溶解炉内で蒸発、気化し、排ガスに
同伴されて炉外に逸失する。スクラップ充填層の温度又
はスクラップ充填層の出口側の排ガス温度が低い場合に
は、排ガス中の亜鉛がスクラップに凝着し、これが再び
溶解炉に装入されて、亜鉛分の循環、濃縮が起こる。On the other hand, when melting zinc-containing cans, plates, and other zinc-containing scraps as raw materials, most of the zinc is vaporized and vaporized in the high-temperature melting furnace, and is entrained in the exhaust gas to accompany the furnace. Lost outside. When the temperature of the scrap packed bed or the temperature of the exhaust gas at the outlet side of the scrap packed bed is low, zinc in the exhaust gas adheres to the scrap, and this is charged into the melting furnace again, and circulation and concentration of zinc content occur. .

【００２８】図３は、縦型充填層炉の出口側の排ガス温
度と縦型充填層炉の入口側及び出口側の排ガス中の亜鉛
濃度の関係を示す図である。出口側の排ガス温度が６０
０℃以下では、排ガス温度が低くなるにしたがい、入口
側の排ガス中の亜鉛濃度が増加しかつ出口側の亜鉛濃度
が急激に減少している。これは、排ガス中の亜鉛がスク
ラップに凝着し、亜鉛分の循環、濃縮が起こっているこ
とを示すものである。FIG. 3 is a graph showing the relationship between the exhaust gas temperature on the outlet side of the vertical packed bed furnace and the zinc concentrations in the exhaust gas on the inlet side and the outlet side of the vertical packed bed furnace. The exhaust gas temperature on the outlet side is 60
At 0 ° C. or lower, the zinc concentration in the exhaust gas on the inlet side increases and the zinc concentration on the outlet side sharply decreases as the exhaust gas temperature decreases. This indicates that the zinc in the exhaust gas is adhering to the scrap and the zinc content is circulated and concentrated.

【００２９】一方、出口側の排ガス温度が６００℃以上
では、入口側と出口側の亜鉛濃度が接近しており、スク
ラップ充填層への亜鉛の凝着はほとんど起こっていな
い。したがって、縦型充填層炉の出口側の排ガス温度を
６００℃以上に保持するように管理すれば、亜鉛分の循
環、濃縮が起こらないことが明らかになった。On the other hand, when the temperature of the exhaust gas on the outlet side is 600 ° C. or higher, the zinc concentration on the inlet side and the zinc concentration on the outlet side are close to each other, and zinc adhesion to the scrap packed bed hardly occurs. Therefore, it was clarified that the zinc content was not circulated and concentrated if the exhaust gas temperature on the outlet side of the vertical packed bed furnace was controlled to be maintained at 600 ° C. or higher.

【００３０】[0030]

【実施例】内容積約７ｍ3の試験転炉を加圧型に改造
し、これに試験縦型充填層炉を連結して、本発明のスク
ラップ溶解方法の試験を行った。試験縦型充填層炉は下
方が拡大した円筒形で、下部の内径約１．５ｍ、上部の
内径約１．２ｍ、内容積が約６ｍ3のものを用いた。EXAMPLE A test converter having an internal volume of about 7 m 3 was modified into a pressure type, and a test vertical packed bed furnace was connected to the test type to test the scrap melting method of the present invention. The test vertical packed bed furnace was a cylindrical one with an enlarged lower part, with an inner diameter of about 1.5 m in the lower part, an inner diameter of about 1.2 m in the upper part, and an inner volume of about 6 m 3 .

【００３１】試験炉における操業の方法は下記の如くで
ある。スクラップの装入に先立って、約１．５tonの溶
銑を種湯として炉内に注入し、底吹きガスによる撹拌と
上吹き酸素吹錬を行いつつ、所定量の造滓剤を投入し炉
内に溶融スラグ層を形成させる。 原料スクラップは約
３０ｃｍ以下のものを選別して使用し、試験縦型充填層
炉に予め装入しておく。The operation method in the test furnace is as follows. Prior to the charging of scrap, about 1.5 tons of hot metal was poured into the furnace as seed water, and while stirring with bottom-blown gas and top-blown oxygen blowing, a predetermined amount of slag-making agent was charged into the furnace. To form a molten slag layer. Raw material scraps of about 30 cm or less are selected and used, and are preliminarily charged in a test vertical packed bed furnace.

【００３２】その後溶解炉及び充填層炉内を加圧して、
炭材の投入と本格的酸素吹錬を開始し、同時にスクラッ
プの炉の上部からの投入を開始する。原料スクラップの
供給は、充填層炉下部に設けた切り出し装置で、間歇的
に所定量切り出して溶解炉内に投入した。炭材として
は、主に粒径１０〜５０mmのコ−クスを使用した。所定
量の原料スクラップの溶解が終わったところで、炉底部
の出湯孔を開口して炉内の溶湯を排出する。溶湯の一部
は炉内に残留させ、次回の溶解の種湯とする。After that, the inside of the melting furnace and the packed bed furnace is pressurized,
Charging of carbon material and full-scale oxygen blowing will be started, and at the same time, scrap will be charged from the top of the furnace. The raw material scrap was supplied by a cutting device provided in the lower part of the packed bed furnace to intermittently cut a predetermined amount of the scrap into the melting furnace. As the carbonaceous material, coke having a particle size of 10 to 50 mm was mainly used. When the predetermined amount of raw material scrap is melted, the tap hole at the bottom of the furnace is opened to discharge the molten metal in the furnace. Part of the melt is left in the furnace and used as the seed melt for the next melt.

【００３３】試験炉における主要な操業条件の範囲は、
下記の如くである。 原料スクラップ装入量 ４．５〜５．５ton／ヒ−ト 造滓剤装入量 ０．１〜０．２ton／ヒ−ト 炉内雰囲気圧力 １．０〜３．０×１０2ｋＰａ（絶対圧） 送酸速度 ７００〜２１００Nm3／h 炭材供給速度 ５００〜１５００kg／h 底吹きＡｒガス流量 １０〜３０Nm3／h 二次燃焼率 ４５〜９０％ 炉内溶融スラグ存在量 １．０〜２．０ton 平均スクラップ予熱温度 ８００〜１０００℃ 充填層炉出口排ガス温度 ６００℃以上。The range of major operating conditions in the test furnace is:
It is as follows. Raw material scrap charging amount 4.5 to 5.5 ton / heat Slag-forming agent charging amount 0.1 to 0.2 ton / heat Furnace atmosphere pressure 1.0 to 3.0 × 10 2 kPa (absolute Pressure) Acid transfer rate 700 to 2100 Nm 3 / h Carbon material supply rate 500 to 1500 kg / h Bottom blow Ar gas flow rate 10 to 30 Nm 3 / h Secondary combustion rate 45 to 90% Amount of molten slag in the furnace 1.0 to 2 0.0 ton Average scrap preheating temperature 800 to 1000 ° C Packed bed furnace outlet exhaust gas temperature 600 ° C or higher.

【００３４】ダスト量が少なくかつスクラップ充填層の
差圧の上昇が少なくて、安定な操業が可能な範囲を明ら
かにするために、炉内雰囲気圧力及びＦ／Ｖの値を変え
て、ダスト発生量とスクラップ充填層の差圧の上昇状況
を調査した結果を表１に示す。 ここで、溶解炉の内容
積Ｖは築炉時の値を使用した。ダスト発生量は、縦型充
填層炉の後流に設けたサイクロン集塵器で捕集されたも
ので、溶解炉から飛出した炭材、粒状スラグ、酸化鉄ダ
スト、粒鉄等のうち、スクラップ充填層で捕集されなか
ったものの総量である。また、スクラップ充填層の差圧
の上昇は、殆ど上昇せず安定なレベルを保つ場合と、異
常な上昇と吹き抜け現象を繰り返す場合があるので、異
常な上昇の有無により判断した。In order to clarify the range in which the amount of dust is small and the differential pressure in the scrap packed bed does not rise so much that stable operation is possible, the atmospheric pressure in the furnace and the value of F / V are changed to generate dust. Table 1 shows the results of the investigation of the amount and the increase in the differential pressure of the scrap packed bed. Here, the internal volume V of the melting furnace used the value at the time of furnace construction. The amount of dust generated was collected by a cyclone dust collector provided in the downstream of the vertical packed bed furnace, and among the carbonaceous materials, granular slag, iron oxide dust, granular iron, etc. that jumped out of the melting furnace, This is the total amount that was not collected in the scrap packed bed. Further, the increase in the differential pressure of the scrap-filled layer may be maintained at a stable level with almost no increase or the abnormal increase and the blow-through phenomenon may be repeated.

【００３５】表１においては、本発明の範囲内の条件の
ものを実施例として、範囲外の条件のものを比較例とし
て表示した。表１の結果から、本発明の範囲内の条件で
は、ダスト量が少なくかつスクラップ充填層の差圧の異
常な上昇がなくて安定な操業が可能であるが、本発明の
範囲外では、ダスト発生量及びスクラップ充填層の差圧
の異常な上昇が起こることが明らかになった。In Table 1, the conditions within the range of the present invention are shown as examples, and the conditions outside the range are shown as comparative examples. From the results of Table 1, under the conditions of the present invention, the amount of dust is small and stable operation is possible without an abnormal increase in the differential pressure of the scrap packed bed. It was revealed that an abnormal increase in the generated amount and the differential pressure of the scrap packed bed occurs.

【００３６】[0036]

【表１】 [Table 1]

【００３７】次に、表１の実施例３及び実施例５の場合
について、亜鉛を含む原料スクラップを使用し、試験縦
型充填層炉内のスクラップ充填層の高さを変え、出口側
の排ガス温度が所定の値になるように調節して、出口側
の排ガス中の亜鉛濃度の測定を行った。出口側の排ガス
温度としては４００、５００、６００、７００℃の４水
準で試験した。実際には、出口側の排ガス温度は操業中
に変動するので、設定値±３０℃の範囲に入るように調
整した。測定の結果を表２に示す。Next, for the cases of Example 3 and Example 5 in Table 1, using zinc-containing raw material scrap, the height of the scrap packed bed in the test vertical packed bed furnace was changed, and the exhaust gas on the outlet side was changed. The temperature was adjusted to a predetermined value, and the zinc concentration in the exhaust gas on the outlet side was measured. The exhaust gas temperature on the outlet side was tested at four levels of 400, 500, 600 and 700 ° C. In practice, the temperature of the exhaust gas on the outlet side fluctuates during operation, so it was adjusted to fall within the set value ± 30 ° C range. Table 2 shows the measurement results.

【００３８】出口側の排ガス中の亜鉛濃度の測定値は、
約１０分のサンプリングを数回行った測定結果の平均値
である。また、装入する原料スクラップの亜鉛濃度等に
よって亜鉛濃度のレベルが変動するので、表２では、実
施例３及び実施例５いずれの場合も、出口側のガス温度
６００℃での排ガス中の亜鉛濃度に対する相対値を指数
として表示した。The measured value of zinc concentration in the exhaust gas on the outlet side is
It is an average value of measurement results obtained by performing sampling for about 10 minutes several times. Further, since the zinc concentration level varies depending on the zinc concentration of the raw material scrap to be charged, in Table 2 both in Example 3 and Example 5, zinc in the exhaust gas at the outlet side gas temperature of 600 ° C. The relative value to the concentration was displayed as an index.

【００３９】[0039]

【表２】 [Table 2]

【００４０】表２の結果から、出口側の排ガス温度が６
００℃以下では、排ガス温度が低くなるにしたがい出口
側の亜鉛濃度が急激に減少しており、亜鉛がスクラップ
に凝着していると推定される。一方、６００℃以上では
排ガス中の亜鉛がほぼ一定のレベルを保っており、亜鉛
がスクラップに凝着していないことを示している。した
がって、縦型充填層炉の出口側の排ガス温度が６００℃
以上になるように管理すれば、亜鉛分の循環、濃縮が起
こらないことが確かめられた。From the results shown in Table 2, the exhaust gas temperature on the outlet side was 6
Below 00 ° C., the zinc concentration at the outlet side drastically decreases as the exhaust gas temperature decreases, and it is estimated that zinc adheres to scrap. On the other hand, at 600 ° C. or higher, the zinc in the exhaust gas maintains a substantially constant level, indicating that zinc has not adhered to the scrap. Therefore, the exhaust gas temperature on the outlet side of the vertical packed bed furnace is 600 ° C.
It was confirmed that the zinc content does not circulate and concentrate if the above management is performed.

【００４１】[0041]

【発明の効果】本発明によれば、エネルギ−コストの低
い炭材を使用しかつ高い生産速度で鉄スクラップの溶解
をすることができる。とくに、転炉型の鉄スクラップの
溶解炉と予熱炉を直結し、現行転炉法と同等又はそれ以
上のＦ／Ｖの値で酸素ガスを供給しても、炉外へのスラ
グやダストの飛散ロスが少なく、予熱炉における閉塞等
のトラブルのない安定な操業が可能となった。According to the present invention, it is possible to melt iron scrap at a high production rate using a carbon material having low energy cost. In particular, even if a converter-type iron scrap melting furnace and a preheating furnace are directly connected and oxygen gas is supplied at an F / V value equal to or higher than that of the current converter method, slag and dust outside the furnace can be generated. With little scattering loss, stable operation is possible without trouble such as blockage in the preheating furnace.

【００４２】さらに、溶解炉と予熱炉を直結したシステ
ムにおいて、原料スクラップ中に含まれる亜鉛分の循
環、濃縮が起こらない操業条件を明らかにした。Furthermore, in the system in which the melting furnace and the preheating furnace are directly connected, the operating conditions under which the circulation and concentration of zinc contained in the raw material scrap do not occur have been clarified.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の鉄スクラップの溶解方法を実施するた
めの溶解装置の例を示す図である。FIG. 1 is a diagram showing an example of a melting apparatus for carrying out the method for melting iron scrap of the present invention.

【図２】安定な操業が可能な溶解炉内の雰囲気圧力Ｐと
Ｆ／Ｖの値の関係を示す図である。FIG. 2 is a diagram showing a relationship between an atmospheric pressure P and a value of F / V in a melting furnace capable of stable operation.

【図３】縦型充填層炉の出口側の排ガス温度と縦型充填
層炉の入口側及び出口側の排ガス中の亜鉛濃度の関係を
示す図である。FIG. 3 is a diagram showing the relationship between the exhaust gas temperature on the outlet side of a vertical packed bed furnace and the zinc concentration in the exhaust gas on the inlet side and the outlet side of the vertical packed bed furnace.

【符号の説明】[Explanation of symbols]

１ 溶解炉炉体 ２ 上吹き酸素ランス ３ 底吹き羽口 ４ 炉口シ−ル装置 ５ 排ガスダクト ６ 耐火物 ７ 縦型充填層炉 ８ スクラップ供給速度制御手段 ９ 炭材供給装置 １０ 鉄浴 １１ 溶融スラグ層 １２ 出湯孔 DESCRIPTION OF SYMBOLS 1 Melting furnace furnace body 2 Top blown oxygen lance 3 Bottom blown tuyere 4 Furnace mouth seal device 5 Exhaust gas duct 6 Refractory 7 Vertical packed bed furnace 8 Scrap supply rate control means 9 Carbon material supply device 10 Iron bath 11 Melting Slag layer 12 tap hole

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 酸素ガスを吹き込んで炭材を燃焼発熱さ
せて鉄スクラップを溶解する溶解炉と、該溶解炉で発生
する高温の排ガスを導入して溶解炉に装入する原料鉄ス
クラップの予熱を行う縦型充填層炉を連結し、溶解炉内
の雰囲気圧力を、溶解炉の内容積及び酸素ガスの供給速
度に対して、下式の関係を満たすように調節することを
特徴とする鉄スクラップの高速溶解法。 Ｐ ≧０．００５(Ｆ／Ｖ)＋１．０ Ｐ：溶解炉内の雰囲気圧力(１０2ｋＰａ） Ｆ：酸素ガスの供給速度(Ｎｍ3／ｈ) Ｖ：溶解炉の内容積(ｍ3)1. A melting furnace for injecting oxygen gas to burn and heat a carbonaceous material to melt iron scrap, and a preheating of raw iron scrap to be charged into the melting furnace by introducing high-temperature exhaust gas generated in the melting furnace. Fe is characterized by connecting a vertical packed bed furnace for performing the above, and adjusting the atmospheric pressure in the melting furnace so as to satisfy the relationship of the following formula with respect to the internal volume of the melting furnace and the supply rate of oxygen gas. Fast scrap melting method. P ≧ 0.005 (F / V) +1.0 P: Atmospheric pressure in the melting furnace (10 2 kPa) F: Oxygen gas supply rate (Nm 3 / h) V: Internal volume of the melting furnace (m 3 ) 【請求項２】 原料鉄スクラップの予熱を行う縦型充填
層炉の出口のガス温度を６００℃以上に保つことを特徴
とする請求項１記載の鉄スクラップの高速溶解法。2. The high-speed melting method for iron scrap according to claim 1, wherein the gas temperature at the outlet of the vertical packed bed furnace for preheating the raw iron scrap is maintained at 600 ° C. or higher.
JP30700795A 1995-11-27 1995-11-27 Method for melting iron scrap at high speed Withdrawn JPH09143523A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP30700795A JPH09143523A (en) 1995-11-27 1995-11-27 Method for melting iron scrap at high speed

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP30700795A JPH09143523A (en) 1995-11-27 1995-11-27 Method for melting iron scrap at high speed

Publications (1)

Publication Number Publication Date
JPH09143523A true JPH09143523A (en) 1997-06-03

Family

ID=17963900

Family Applications (1)

Application Number Title Priority Date Filing Date
JP30700795A Withdrawn JPH09143523A (en) 1995-11-27 1995-11-27 Method for melting iron scrap at high speed

Country Status (1)

Country Link
JP (1) JPH09143523A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019167608A (en) * 2018-03-26 2019-10-03 Ｊｆｅスチール株式会社 Lightweight refuse-removing device and metal-melting facility

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019167608A (en) * 2018-03-26 2019-10-03 Ｊｆｅスチール株式会社 Lightweight refuse-removing device and metal-melting facility

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