JPH01234508A - Method for operating blast furnace - Google Patents

Method for operating blast furnace

Info

Publication number
JPH01234508A
JPH01234508A JP5742788A JP5742788A JPH01234508A JP H01234508 A JPH01234508 A JP H01234508A JP 5742788 A JP5742788 A JP 5742788A JP 5742788 A JP5742788 A JP 5742788A JP H01234508 A JPH01234508 A JP H01234508A
Authority
JP
Japan
Prior art keywords
coke
layer
ore
blast furnace
charged
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.)
Pending
Application number
JP5742788A
Other languages
Japanese (ja)
Inventor
Takashi Wada
隆 和田
Tomonori Kato
友則 加藤
Sumiyuki Kishimoto
岸本 純幸
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.)
JFE Engineering Corp
Original Assignee
NKK Corp
Nippon Kokan Ltd
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 NKK Corp, Nippon Kokan Ltd filed Critical NKK Corp
Priority to JP5742788A priority Critical patent/JPH01234508A/en
Publication of JPH01234508A publication Critical patent/JPH01234508A/en
Pending legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21BMANUFACTURE OF IRON OR STEEL
    • C21B5/00Making pig-iron in the blast furnace
    • C21B5/008Composition or distribution of the charge
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21BMANUFACTURE OF IRON OR STEEL
    • C21B5/00Making pig-iron in the blast furnace
    • C21B5/007Conditions of the cokes or characterised by the cokes used

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture Of Iron (AREA)

Abstract

PURPOSE:To obtain molten low Si iron without any changing the total coke cost, by mixing the coke having high reactivity with sintered ore, and by charging the mixture into the ore layer and the coke having low reactivity as it is into the coke layer. CONSTITUTION:The coke charging into a blast furnace is divided into two, which are the coke having high reactivity of corresponding quantity to 5-50% of the total coke charging wt. and the balance coke having low reactivity. Then, the above coke having high reactivity is mixed with the iron ore raw material to make the ore layer. Further, the above coke having low reactivity is charged in the coke layer as it is.

Description

【発明の詳細な説明】 [産業上の利用分野] 本発明は溶銑中のSiを低下させる高炉の操業方法に関
するものである。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a blast furnace operating method for reducing Si in hot metal.

[従来の技術] 高炉から出銑される溶銑中のSiを低下させることにつ
いては従来から種々の検討が重ねられてきたところであ
り、このSiの低減は高級鋼の製造または転炉製鋼にお
けるスラグレス操業を容易ならしめるものである。
[Prior Art] Various studies have been made to reduce Si in hot metal tapped from a blast furnace. It makes it easier.

高炉内におけるSiの移行反応は次のように考えられる
The Si transfer reaction in the blast furnace can be considered as follows.

(イ)  SiO□(II ) + C= SiO(g
) +  Co(g)(ロ)  SiO(g)+ C=
 Si +Co(g)主としてコークス灰分中のSiO
2がコークスと高温で反応してSiOガスを発生し、こ
のSiOが溶銑中のCに還元されて溶銑中のSiとなる
。そこでこのような溶銑中のSiの低減をはかるため、 ■装入物中への焼結鉱の配合率を増加し、あるいは焼結
鉱塩基度の上昇、更には装入物へのMgOの添加などの
装入物の性状改善、■送風にないする湿分添加や送風温
度低下のような羽口先温度の低下、 ■スラグ塩基度の上昇、 ■溶銑温度の低下、 ■羽口先からミルスケールなどの酸化物の吹き込み、 などが提案されている。
(a) SiO□(II) + C= SiO(g
) + Co(g)(b) SiO(g)+ C=
Si + Co (g) Mainly SiO in coke ash
2 reacts with coke at high temperature to generate SiO gas, which is reduced to C in the hot metal and becomes Si in the hot metal. Therefore, in order to reduce the amount of Si in hot metal, it is possible to increase the blending ratio of sintered ore in the charge, increase the basicity of the sintered ore, or add MgO to the charge. Improving the properties of the charge, such as ■ Decreasing the tuyere tip temperature by adding moisture to the blast and lowering the blast temperature, ■ Increasing slag basicity, ■ Decreasing the hot metal temperature, ■ Mill scale from the tuyere tip, etc. Injection of oxides, etc. have been proposed.

[発明が解決しようとする課題] しかしながら、上記したような従来技術によるものはそ
れぞれ問題点を有しており好ましい手法とはなしえない
。即ち■は何れにしてもコストアップになり、また焼結
鉱における塩基度の上昇には上限があって経済的で的確
な方法となし得ないことは明らかであり、また■は燃料
比を上昇させコストアップとなるか、或は設備的に制限
があって結局は■と同じ不利がともなう。■はスラグの
粘性に影響することから当然に制限を受け、■の方法は
出銑および出滓の何れの面からも制限を受けるので、十
分な低Si化を期待することは出来ない。また、■も操
業上煩雑であるたけでなく、■と同様な制限を受は好ま
しい方法とはなしえない。
[Problems to be Solved by the Invention] However, each of the above-mentioned conventional techniques has problems and cannot be considered as a preferable technique. In other words, (2) increases the cost in any case, and there is an upper limit to the increase in basicity in sintered ore, so it is clear that it cannot be done as an economical and accurate method, and (2) increases the fuel ratio. Either this will increase the cost, or there will be restrictions on equipment, resulting in the same disadvantages as in (2). The method (2) is naturally limited because it affects the viscosity of the slag, and the method (2) is limited in terms of both iron tapping and slag tapping, so a sufficient reduction in Si cannot be expected. In addition, (2) is not only complicated in operation, but also has the same limitations as (2), so it cannot be considered a preferable method.

本発明はかかる事情に鑑みてなされたもので、上記の問
題点を解決し溶銑中のSiを確実に所期の量に低下させ
、しかも特別な操業的煩雑を伴うことなく経済的にも十
分成立し得る高炉による低シリコン操業法を提供しよう
とするものである。
The present invention has been made in view of the above circumstances, and it solves the above problems, reliably reduces the Si content in hot metal to the desired level, and is economically sufficient without any special operational complications. The purpose is to provide a viable low-silicon operating method for blast furnaces.

し課題を解決するための手段] 本発明による高炉の操業方法は、炉頂から鉄鉱石原料と
コークスを交互にて装入して炉内に形成される鉱石層お
よびコークス層に関し、全コークス装入量の5%乃至5
0%に相当する量を反応性の高いコークス(以下、高R
Iコークスという)として鉄鉱石原料に混合して鉱石層
とし、残余の量のコークスを反応性の低いコークス(以
下、低RIコークスという)としてコークス層とするこ
とを特徴とする。
[Means for Solving the Problems] The method of operating a blast furnace according to the present invention relates to the ore layer and the coke layer formed in the furnace by alternately charging iron ore raw material and coke from the top of the furnace. 5% to 5 of the input amount
0% of highly reactive coke (hereinafter referred to as high R
It is characterized in that it is mixed with iron ore raw material as I coke to form an ore layer, and the remaining amount of coke is used as low reactivity coke (hereinafter referred to as low RI coke) to form a coke layer.

高RIコークスを鉱石と混合して高炉に装入した場合、
鉱石が従来法より格段に進むため、原料である酸化鉄の
高温性状が向上し、融点が高くなって所謂溶は落ち温度
が上昇する。その結果高炉内の融着帯レベルが低下し、
(ロ)の反応が主に行われる融着帯と羽目間の距離が減
少するため、コークス中の灰分から発生するSi○ガス
が融着帯の下を滴下する溶銑中のCに還元されて溶銑中
に入る機会が少なくなり低Siの溶銑が製造される。鉱
石層に混合される高Rエコークスは全装入コークスの5
%未満では溶は落ち温度の上昇の効果はみられず、これ
が50%を越えるとコークスの粉化により通気性が阻害
される。
When high RI coke is mixed with ore and charged into a blast furnace,
Because the ore is processed much more advanced than in the conventional method, the high-temperature properties of the raw material iron oxide are improved, the melting point becomes higher, so-called melting slows down, and the temperature rises. As a result, the cohesive zone level in the blast furnace decreases,
As the distance between the cohesive zone and the grain where the reaction (b) mainly takes place decreases, the Si○ gas generated from the ash in the coke is reduced to C in the hot metal dripping below the cohesive zone. There is less opportunity for the metal to enter the hot metal, and low-Si hot metal is produced. The high R echo mixed into the ore layer accounts for 5% of the total coke charge.
If it is less than 50%, the melting will drop and no effect of increasing the temperature will be seen, and if it exceeds 50%, the permeability will be inhibited due to coke powdering.

[実施例] 添付の図面を参照しながら本発明の実施例について説明
する。第1図は本発明の方法に用いられる高炉1と原料
装入装?1ilOを示す図である。2は炉頂の装入口、
3,4はそれぞれ高炉内の上部に形成される鉱石層、コ
ークス層で、5は原料が半溶融状態になっている融着帯
、6は羽口、7は湯溜りである。この融着帯の形状また
は高さは高炉の操業条件によって変わるものである。高
炉外の原料装入装置10は配合ホッパー11、ホッパー
下ベルト12および装入ベルト13を有し、配合ホッパ
ー11はまた種類の異なる原料がそれぞれ貯溜されてい
る複数のビンからなり、配合ホッパー11のビン14に
は反応性の高いコークス(以下、高RIコークスという
)、ビン15には反応性の低いコークス(以下、低RI
コークスという)が貯溜され、またビン16,17.1
8には鉄鉱石原料である焼結鉱、焼結ペレット、鉄鉱石
がそれぞれ貯溜されている。
[Examples] Examples of the present invention will be described with reference to the accompanying drawings. Figure 1 shows the blast furnace 1 and raw material charging equipment used in the method of the present invention. FIG. 2 is the charging port at the top of the furnace;
3 and 4 are an ore layer and a coke layer formed in the upper part of the blast furnace, 5 is a cohesive zone in which the raw material is in a semi-molten state, 6 is a tuyere, and 7 is a sump. The shape or height of this cohesive zone varies depending on the operating conditions of the blast furnace. The raw material charging device 10 outside the blast furnace has a blending hopper 11, a hopper lower belt 12, and a charging belt 13. The blending hopper 11 also includes a plurality of bins each storing different types of raw materials. Bin 14 contains coke with high reactivity (hereinafter referred to as high RI coke), and bin 15 contains coke with low reactivity (hereinafter referred to as low RI coke).
(called coke) is stored in bins 16 and 17.1.
8 stores sintered ore, sintered pellets, and iron ore, which are raw materials for iron ore.

このように構成された第1図の装置についてその作用を
説明する。ビン15に貯溜された□低RIコークスは他
の原料と混合されずにそのまま、ホッパー下ベルト12
および装入ベルト13を経て高炉1の装入口2から高炉
内に装入され、コークス層4を形成する。次いで、ビン
14に貯溜された高RIコークスはビン16乃至18に
貯溜されている鉄鉱石原料とともに前記ベルト12.1
3を経て高炉内に装入され、前記コークス層の上に鉱石
層を形成する。以上のようにして、コークス層と鉱石層
が交互に高炉内に形成され、荷下がりとともに羽口6か
ら吹き込まれる熱風により装入された鉄鉱石原料は温度
が上昇し、還元反応が進行する。鉄鉱石原料の層の中に
反応性の高い高RIコークスが含まれているので、鉄鉱
石の還元が進み、Feの割合が増加して溶は落ち温度が
上昇し、融着帯のレベルが低下する。一方、コークス層
は低RIコークスはそのままコークス層となるので、高
温強度は十分で、高炉内の通気性は確保される。
The operation of the apparatus shown in FIG. 1 constructed in this way will be explained. □Low RI coke stored in the bin 15 is directly transferred to the hopper lower belt 12 without being mixed with other raw materials.
The coke is then charged into the blast furnace from the charging port 2 of the blast furnace 1 via the charging belt 13 to form a coke layer 4. Next, the high RI coke stored in the bin 14 is transferred to the belt 12.1 together with the iron ore raw material stored in the bins 16 to 18.
3 and then charged into a blast furnace to form an ore layer on top of the coke layer. As described above, coke layers and ore layers are alternately formed in the blast furnace, and as the load is lowered, the temperature of the charged iron ore raw material rises due to hot air blown from the tuyere 6, and a reduction reaction progresses. Since the layer of iron ore raw material contains highly reactive high RI coke, reduction of the iron ore progresses, the proportion of Fe increases, the melt drops, the temperature rises, and the level of the cohesive zone increases. descend. On the other hand, since the low RI coke becomes the coke layer as it is, the coke layer has sufficient high-temperature strength and the ventilation inside the blast furnace is ensured.

湯溜り7で発生したコークス中の灰分から発生するSi
Oガスが融着帯から滴下された溶銑中のCに還元されて
溶銑中のSiとなるが、融着帯レベルが低い場合は高い
場合に比較して、前記SiOガスと溶銑の液滴と接触す
る時間が短く、従って溶銑中のSiは低下される。
Si generated from ash in coke generated in hot water pool 7
O gas is reduced to C in the hot metal dropped from the cohesive zone and becomes Si in the hot metal, but when the cohesive zone level is low, compared to when it is high, the SiO gas and the droplets of hot metal are The contact time is short, so the Si content in the hot metal is reduced.

次に本実施例の具体的な数値例を挙げる。全装入コーク
スの75%を低RIコークスとしてコークス層4に、残
りの25%を高RIコークスとして鉱石層3に装入して
操業したところ、溶銑中のSiは従来例の0.28%に
たいして0.19%に低下した。また、通気抵抗は、P
R,POをそれぞれ炉頂圧(g/cm2、以下同じ)、
送風圧、■を風量(Nm3/min )として、通気抵
抗指数K(−(PR2−Po2)/■17)で表すと、
これが従来例で2.77であったものが、この実施例で
は2.79とわずかながら大きくなったが、炉況に影響
する程度の差は認められなかった。
Next, specific numerical examples of this example will be given. When we operated with 75% of the total coke charged as low RI coke in coke layer 4 and the remaining 25% as high RI coke in ore layer 3, Si in the hot metal was 0.28% compared to the conventional example. However, it decreased to 0.19%. In addition, the ventilation resistance is P
R and PO are respectively furnace top pressure (g/cm2, same below),
When the blowing pressure, ■ is the air volume (Nm3/min), and it is expressed as the ventilation resistance index K (-(PR2-Po2)/■17),
Although this was 2.77 in the conventional example, it was slightly larger to 2.79 in this example, but the difference was not significant enough to affect the furnace condition.

[発明の効果] 本発明によれば、反応性の高いコークスを焼結鉱に混合
して鉱石層に、反応性の低いコークスはそのままコーク
ス層に装入するので、特別な操業上の煩雑を伴うことな
くトータルのコークスのコストを変えることなく経済的
にも十分成立し得る方法で低Si溶銑が得られる。
[Effects of the Invention] According to the present invention, highly reactive coke is mixed with sintered ore and charged into the ore layer, and less reactive coke is directly charged into the coke layer, thereby eliminating special operational complications. Low-Si hot metal can be obtained by an economically viable method without changing the total cost of coke.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の方法に用いられる高炉と原料装入装置
を示す図である。 1・・・高炉、2・・装入向、3・・鉱石層、4・・・
コークス層、5・・融着帯、6・・・羽口、7・・・湯
溜り、10.・・・原料装入装置、11・・・配合ホッ
パー、12・・・ホッパー下ベルト、13・・・装入ベ
ルト、14乃至18・・・ビン。
FIG. 1 is a diagram showing a blast furnace and a raw material charging device used in the method of the present invention. 1...Blast furnace, 2...Charging direction, 3...Ore layer, 4...
Coke layer, 5... cohesive zone, 6... tuyere, 7... pool, 10. ...Raw material charging device, 11...Blending hopper, 12...Hopper lower belt, 13...Charging belt, 14 to 18...Bin.

Claims (1)

【特許請求の範囲】[Claims] 溶銑中のSiを低下させる高炉の操業方法において、炉
頂から交互に原料として装入される鉱石層およびコーク
ス層に関し、全コークス装入量の5%乃至50%に相当
する量を反応性の高いコークスとして鉄鉱石原料に混合
して鉱石層に、残余の量のコークスを反応性の低いコー
クスとしてそのままコークス層に装入することを特徴と
する高炉の操業方法。
In a blast furnace operating method for reducing Si in hot metal, an amount equivalent to 5% to 50% of the total amount of coke charged is added to the ore layer and coke layer that are alternately charged as raw materials from the top of the furnace. A blast furnace operating method characterized in that high coke is mixed with iron ore raw material and charged into the ore layer, and the remaining amount of coke is charged as low reactivity coke into the coke layer.
JP5742788A 1988-03-11 1988-03-11 Method for operating blast furnace Pending JPH01234508A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5742788A JPH01234508A (en) 1988-03-11 1988-03-11 Method for operating blast furnace

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5742788A JPH01234508A (en) 1988-03-11 1988-03-11 Method for operating blast furnace

Publications (1)

Publication Number Publication Date
JPH01234508A true JPH01234508A (en) 1989-09-19

Family

ID=13055356

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5742788A Pending JPH01234508A (en) 1988-03-11 1988-03-11 Method for operating blast furnace

Country Status (1)

Country Link
JP (1) JPH01234508A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008106320A (en) * 2006-10-26 2008-05-08 Jfe Steel Kk Method for operating blast furnace

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008106320A (en) * 2006-10-26 2008-05-08 Jfe Steel Kk Method for operating blast furnace

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