JPH0723493B2 - How to shut down the iron ore fluidized bed reduction unit - Google Patents
How to shut down the iron ore fluidized bed reduction unitInfo
- Publication number
- JPH0723493B2 JPH0723493B2 JP26928787A JP26928787A JPH0723493B2 JP H0723493 B2 JPH0723493 B2 JP H0723493B2 JP 26928787 A JP26928787 A JP 26928787A JP 26928787 A JP26928787 A JP 26928787A JP H0723493 B2 JPH0723493 B2 JP H0723493B2
- Authority
- JP
- Japan
- Prior art keywords
- fluidized bed
- furnace
- ore
- bed reduction
- reduction furnace
- 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.)
- Expired - Lifetime
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- Manufacture Of Iron (AREA)
- Crucibles And Fluidized-Bed Furnaces (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は溶融還元法・高炉法等に使用するための、鉄鉱
石を流動層還元炉で還元する鉄鉱石還元装置の運転停止
方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for shutting down an iron ore reducing apparatus for reducing iron ore in a fluidized bed reduction furnace for use in a smelting reduction method, a blast furnace method, and the like.
［従来の技術］ 鉄鉱石を還元して溶銑を製造するために、高炉を使用す
る方法、シャフト炉で還元した鉄鉱石を電気炉で溶解す
る方法等が従来から採用されている。[Prior Art] In order to reduce iron ore to produce hot metal, a method of using a blast furnace, a method of melting iron ore reduced in a shaft furnace in an electric furnace, and the like have been conventionally adopted.
近時このような従来の溶銑製造技術に代わるものとし
て、溶融還元精練法が注目を浴びている。この方法で使
用する溶融還元炉は使用する原料に制約を受けることな
く、より小規模な設備により鉄系合金の溶湯を製造する
ことを目的として開発されたものである。Recently, the smelting reduction refining method has been attracting attention as an alternative to the conventional hot metal production technology. The smelting reduction furnace used in this method was developed for the purpose of producing a molten iron-based alloy by a smaller-scale facility without being restricted by the raw material used.
上述する溶融還元法の一例として、本発明者らは先に第
３図に示すフローで構成される方法を特開昭61-64807号
公報に提案している。As an example of the above-mentioned smelting reduction method, the present inventors have previously proposed a method constituted by the flow shown in FIG. 3 in Japanese Patent Laid-Open No. 61-64807.
この方法によるとき、次のようにして溶銑が製造され
る。即ち鉄鉱石101及び石灰石102は流動層予熱炉103内
で石炭104と空気105との燃焼反応で生じた熱によって加
熱される。その結果、石灰石102（CaCO3）は石灰石（Ca
O）となって流動層還元炉106に供給される。According to this method, hot metal is manufactured as follows. That is, the iron ore 101 and the limestone 102 are heated in the fluidized bed preheating furnace 103 by the heat generated by the combustion reaction between the coal 104 and the air 105. As a result, limestone 102 (CaCO 3 )
O) and supplied to the fluidized bed reduction furnace 106.
流動層還元炉106内では流動状態の予熱鉱石及び生石灰
に石灰107及び酸素又は酸素含有ガスが吹き込まれる。
この石灰107は、流動層還元炉106内で予熱鉱石と熱交換
し、また酸素との反応による部分燃焼によって熱分解す
る。これにより、石灰107は、還元性のガスを発生する
と共に、チャー109となる。In the fluidized bed reduction furnace 106, lime 107 and oxygen or an oxygen-containing gas is blown into the preheated ore and quick lime in a fluidized state.
This lime 107 exchanges heat with preheated ore in the fluidized bed reduction furnace 106, and is thermally decomposed by partial combustion due to the reaction with oxygen. As a result, the lime 107 generates a reducing gas and becomes a char 109.
他方、溶融還元炉110で発生したガス又はそのガスを脱
炭酸処理して得られる還元ガス111は、流動層106からの
燃料ガス112との熱交換によって700〜900℃に昇温され
た後、流動層還元炉106に吹き込まれる。On the other hand, the gas generated in the smelting reduction furnace 110 or the reducing gas 111 obtained by decarbonating the gas is heated to 700 to 900 ° C. by heat exchange with the fuel gas 112 from the fluidized bed 106, It is blown into the fluidized bed reduction furnace 106.
流動層還元炉106に吹き込まれた還元ガス111は石灰107
の熱分解により生成した還元ガスと混合され、流動状態
にある高温の粉粒状鉄鉱石を還元し、還元鉱113を生成
する。The reducing gas 111 blown into the fluidized bed reduction furnace 106 is lime 107
Is mixed with the reducing gas produced by the thermal decomposition of the above, and the high temperature powdery iron ore in a fluidized state is reduced to produce reduced ore 113.
また、流動層予熱炉103内に生成した生石灰114は、予熱
鉱石と共に流動層還元炉106に装入されて、流動層還元
炉106内にあるガスの脱硫を行う。The quick lime 114 generated in the fluidized bed preheating furnace 103 is charged into the fluidized bed reduction furnace 106 together with the preheated ore to desulfurize the gas in the fluidized bed reduction furnace 106.
次いで、該生石灰114は、還元鉱113及びチャー109と共
に流動層還元炉106から排出される。Next, the quicklime 114 is discharged from the fluidized bed reduction furnace 106 together with the reduced ore 113 and the char 109.
このようにして得られた還元鉱113、チャー109及び生石
灰114に対して、溶融還元炉110に於ける熱バランス上必
要な石炭、コークス等の炭材が外部から加えられ、混練
される。Carbon materials such as coal and coke required for heat balance in the smelting reduction furnace 110 are externally added to the thus obtained reduced ore 113, char 109 and quick lime 114, and kneaded.
次いで、混合物は、ブリケットマシン等の塊成化装置11
5によってブリケット116に成型された後、装入装置117
によって溶融還元炉110に装入される。The mixture is then passed through an agglomeration device 11 such as a briquette machine.
After molding into briquette 116 by 5, charging device 117
And is charged into the smelting reduction furnace 110.
この溶融還元炉110には、上吹きランス118から酸素119
が浴に向かって吹き付けられると共に、底吹き羽口120
から浴中に酸素及び炭材が吹き込まれている。In the smelting reduction furnace 110, oxygen 119 is supplied from an upper blowing lance 118.
Is blown into the bath and the bottom blowing tuyere 120
Oxygen and carbonaceous materials have been blown into the bath.
そして、ブリケット116に含まれている炭材、底吹き羽
口120から酸素と共に吹き込まれている炭材、装入装置1
17から供給されたコークス121等の炭材は、上吹きラン
ス118から供給された酸素と反応し、溶融還元炉110内に
大量の熱を発生する。Then, the carbonaceous material contained in the briquette 116, the carbonaceous material blown together with oxygen from the bottom blown tuyere 120, and the charging device 1
The carbonaceous material such as the coke 121 supplied from 17 reacts with the oxygen supplied from the upper blowing lance 118 to generate a large amount of heat in the smelting reduction furnace 110.
この発生熱によって、ブリケット116中の還元鉱113が溶
解し、還元が進行して溶銑となる。The generated heat melts the reduction ore 113 in the briquette 116, and the reduction proceeds to form hot metal.
［発明が解決しようとする問題点］ 一般に粒度の大きさが還元速度に影響を及ぼし、細、粗
粒子のそれぞれに適した還元ガスの空速度がある。[Problems to be Solved by the Invention] Generally, the size of the particle size affects the reduction rate, and there is a reduction gas empty velocity suitable for each of fine and coarse particles.
従って粒度分布の広い粉鉱石を還元する場合に、細粒の
粉鉱石の方が粗粒の粉鉱石より還元が進み高還元度とな
り、還元鉱同志の付着性が増し細粒同志による凝集、或
いは粗粒への凝集が生じ、流動性の悪化、更に流動化停
止のトラブルが発生する危険もある。Therefore, when reducing fine ore with a wide particle size distribution, fine grain ore is reduced more than coarse grain ore and has a higher degree of reduction. There is a risk that agglomeration into coarse particles may occur, the fluidity may be deteriorated, and a trouble of stopping fluidization may occur.
本発明は循環流動層還元炉の停止時における運転方法を
提供するものである。The present invention provides an operating method when the circulating fluidized bed reduction furnace is stopped.
［問題点を解決するための手段］ 本発明は流動層予備還元炉に外部粒子循環装置を付設し
た流動層予備還元炉の停止時に、還元炉に冷ガス体を吹
き込んで炉温を700℃以下に冷却した後、操業を停止す
ることを特徴とする。[Means for Solving Problems] According to the present invention, when the fluidized bed preliminary reduction furnace in which the external particle circulation device is attached to the fluidized bed preliminary reduction furnace is stopped, a cold gas body is blown into the reduction furnace to keep the furnace temperature at 700 ° C. or less. It is characterized in that the operation is stopped after cooling to 0.
以下本発明を図面について説明する。The present invention will be described below with reference to the drawings.
第１図は本発明の一実施例を示す説明図である。FIG. 1 is an explanatory view showing an embodiment of the present invention.
流動層還元炉に外部粒子循環装置を付設し、流動層還元
炉６に上部に設けられている出口にサイクロン31を接続
し還元ガス11と同伴し飛散してきた細粒子を捕捉してい
る。An external particle circulation device is attached to the fluidized bed reduction furnace, and a cyclone 31 is connected to an outlet provided at the upper part of the fluidized bed reduction furnace 6 to capture fine particles that have been scattered along with the reducing gas 11.
そしてサイクロン31の下部には捕捉した粒子を一時溜め
るホッパ32が接続され、このホッパ32で一時貯え所定量
を循環切出装置33で流動層還元炉６に戻すものである。A hopper 32 for temporarily storing the captured particles is connected to the lower part of the cyclone 31, and a predetermined amount is temporarily stored in the hopper 32 and returned to the fluidized bed reduction furnace 6 by the circulation cutting device 33.
一方流動層還元炉６の炉内には複数のガス吹出し口34が
形成されている。また流動層還元炉６の炉底部に充填層
37が形成され、充填層37内に炉底吹き込みノズル38が設
けられている。On the other hand, a plurality of gas outlets 34 are formed in the fluidized bed reduction furnace 6. In addition, a packed bed is provided at the bottom of the fluidized bed reduction furnace 6.
37 is formed, and a furnace bottom blowing nozzle 38 is provided in the packed bed 37.
図中39は粉鉱石、石灰石等の原料25を流動層還元炉６に
装入する為の切出弁、40,42は還元ガスの吹き出し量を
調整するための流量調節弁、43は細粒状の還元鉱の切出
弁、44は細粒状の還元鉱の切出弁である。In the figure, 39 is a cut-off valve for charging the raw material 25 such as powdered ore and limestone into the fluidized bed reduction furnace 6, 40 and 42 are flow rate control valves for adjusting the amount of reducing gas blown out, and 43 is a fine grain. A reduction valve for the ore of reduction, and 44 is a valve for the reduction ore of fine particles.
次に切出弁から粉鉱石、石灰石等の原料25を流動層還元
炉６に装入し還元ガス11を流量調節弁40,42を介してガ
ス吹出し口34,38より吹込むと、最上部のガス吹込みノ
ズル34の上方は全てのガス吹込みノズルの吹き出し量が
加わり、細粒状の原料粒子の終末速度Utより大きい速度
となり、細粒状の原料粒子は還元ガスと反応しながら流
動層還元炉６の上方へ飛散する。Next, the raw material 25 such as powdered ore and limestone is charged into the fluidized bed reduction furnace 6 through the cut-out valve, and the reducing gas 11 is blown from the gas outlets 34 and 38 through the flow rate control valves 40 and 42. Above the gas blowing nozzle 34, the blowing amounts of all the gas blowing nozzles are added, and the velocity becomes higher than the terminal velocity Ut of the fine granular raw material particles, and the fine granular raw material particles react with the reducing gas to perform fluidized bed reduction. Scatter above the furnace 6.
他方粗粒状の原料は細粒状の原料に比べ終末速度Utが大
きい為、ガス吹出し口34で飛散せず、炉下部の充填層37
まで下降する。充填層37内の粗粒子は炉下部に位置する
炉底吹き込みノズル38により適正な流量の還元ガスによ
り還元が確実になされ、切出弁44から粗粒状の還元鉱が
排出され次工程へ送られる。On the other hand, the coarse-grained raw material has a higher terminal velocity Ut than the fine-grained raw material, so that it does not scatter at the gas outlet 34 and the packed bed 37 at the bottom of the furnace
Descend to. Coarse particles in the packed bed 37 are reliably reduced by a reducing gas at a proper flow rate by a furnace bottom blowing nozzle 38 located in the lower part of the furnace, and coarse particles of reducing ore are discharged from the cut-out valve 44 and sent to the next step. .
一方細粒子は流動層還元炉６内で飛散され、炉上部の出
口からサイクロン31で捕捉され、ホッパ32、循環切出装
置33を介し、再び還元が行われる。On the other hand, the fine particles are scattered in the fluidized bed reduction furnace 6, captured by the cyclone 31 from the outlet in the upper part of the furnace, and reduced again through the hopper 32 and the circulation cutting device 33.
そして所望の還元を得られた細粒子の還元鉱は切出弁43
から排出され次工程へ送られる。And the reduction ore of the fine particles that have obtained the desired reduction is cut out by the cut-off valve 43.
And discharged to the next process.
上述の操業において流動層還元炉６は800〜900℃に保持
されている。In the above operation, the fluidized bed reduction furnace 6 is maintained at 800 to 900 ° C.
ところで何らかの異常発生あるいは運転計画により流動
還元炉の操業を停止せざるを得ない情況がある。しかし
ながら800〜900℃の高温状態で流動還元炉の操業を停止
すると、炉内の粉鉱石が還元度合に関係なくスティッキ
ング（粘着）が生じることを見出した。However, there are circumstances in which the operation of the fluidized-bed reduction reactor must be stopped due to some abnormality or operation plan. However, it was found that if the operation of the fluidized-bed reduction furnace is stopped at a high temperature of 800-900 ℃, the ore in the furnace sticks regardless of the degree of reduction.
即ちスティッキングによって粉鉱石同志が付着して、大
粒あるいは大塊になり、かつ極端な場合は全体が固まっ
てしまうことがある。このため運転再開が流動不安のた
め不可能となる。That is, sticking ore powder ores attach to each other to form large grains or large blocks, and in extreme cases, the whole may solidify. For this reason, it is impossible to restart driving due to anxiety about the flow.
このため炉停止時には炉内の鉱石の滞留量を空にすれ
ば、このトラブルは回避できるが、緊急時の停止時では
間に間に合わないし、排出された鉱石の処理、顕熱ロス
等マイナス面が大である。For this reason, this problem can be avoided by emptying the amount of ore in the furnace when the furnace is stopped, but in the event of an emergency stop, it will not be in time, and there are negative aspects such as the processing of the discharged ore and the loss of sensible heat. Is large.
従ってこのトラブルをうまく回避するための手段をうる
ため、以下に説明する実験を行い、効果的な手法を得
た。Therefore, in order to obtain a means for avoiding this trouble well, an experiment described below was conducted, and an effective method was obtained.
即ち本発明者らの実験によると、流動層還元炉における
粉鉱石の塊化率は第２図の通りである。That is, according to the experiments by the present inventors, the agglomeration rate of the fine ore in the fluidized bed reduction furnace is as shown in FIG.
即ち700℃のとき保持時間３時間を境にして４時間で塊
化率５％未満を示すが、900℃においては保持時間１時
間で塊化率30％であった。従って700℃において極めて
著るしい臨界点を示す。That is, at 700 ° C., the agglomeration rate was less than 5% after 4 hours with a holding time of 3 hours, but at 900 ° C. the agglomeration rate was 30% after 1 hour of holding time. Therefore, it shows a very remarkable critical point at 700 ° C.
そこで本発明においては、流動層還元炉の停止時にあた
り、底吹ノズル38から冷ガスを吹き込み、炉内温度700
℃以下の冷却を得て操業を停止するときは、粉鉱石のス
ティッキングの発生をみない。Therefore, in the present invention, when the fluidized bed reduction furnace is stopped, a cold gas is blown from the bottom blowing nozzle 38 so that the temperature inside the furnace is 700
No sticking of fine ore is observed when the operation is stopped after cooling below ℃.
又流動層還元炉の起動に当っても、700℃に保持して流
動層を生成した後昇温するときは、炉内の粉鉱石は正常
である。Even when the fluidized bed reduction furnace is started up, when the temperature is maintained at 700 ° C. to generate the fluidized bed and then the temperature is raised, the fine ore in the furnace is normal.
［発明の効果］ 本発明は流動層還元炉における停止時に、炉内温度を70
0℃以下に低下させて炉の操業を停止することで、炉内
原料のスティッキングを防止しうるので、装置の操業安
全上効果が大である。[Advantages of the Invention] The present invention reduces the temperature inside the fluidized bed reduction furnace to 70
By stopping the operation of the furnace by lowering it to 0 ° C. or less, sticking of the raw material in the furnace can be prevented, and thus the effect on the operational safety of the apparatus is great.
第１図は本発明の説明図、第２図は塊化率の図表、第３
図は従来法の説明図である。 1:鉄鉱石、2:石灰石 6:流動層還元炉、11:還元ガス 25:原料、31:サイクロン 32:ホッパ、33:循環切出装置 34:ガス吹出し口、37:充填層 38:炉底吹き込みノズル、39:切出弁 40,42:流量調節弁、43,44:切出弁FIG. 1 is an explanatory view of the present invention, FIG. 2 is a diagram of the agglomeration rate, and FIG.
The figure is an illustration of the conventional method. 1: Iron ore, 2: Limestone 6: Fluidized bed reduction furnace, 11: Reduction gas 25: Raw material, 31: Cyclone 32: Hopper, 33: Circulation cutting device 34: Gas outlet, 37: Packed bed 38: Furnace bottom Blow-out nozzle, 39: Cutoff valve 40,42: Flow control valve, 43,44: Cutoff valve
Claims (1)
還元部の運転停止時に、還元炉に冷ガスを吹き込んで炉
温を700℃以下に冷却した後、操業を停止することを特
徴とする鉄鉱石流動層還元装置の運転停止方法。1. A facility for producing reduced ore, characterized in that when the operation of the fluidized bed reducing section is stopped, cold gas is blown into the reducing furnace to cool the furnace temperature to 700 ° C. or lower, and then the operation is stopped. Method for stopping operation of iron ore fluidized bed reduction device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26928787A JPH0723493B2 (en) | 1987-10-27 | 1987-10-27 | How to shut down the iron ore fluidized bed reduction unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26928787A JPH0723493B2 (en) | 1987-10-27 | 1987-10-27 | How to shut down the iron ore fluidized bed reduction unit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01111809A JPH01111809A (en) | 1989-04-28 |
| JPH0723493B2 true JPH0723493B2 (en) | 1995-03-15 |
Family
ID=17470252
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26928787A Expired - Lifetime JPH0723493B2 (en) | 1987-10-27 | 1987-10-27 | How to shut down the iron ore fluidized bed reduction unit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0723493B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101009020B1 (en) * | 2003-12-16 | 2011-01-17 | 주식회사 포스코 | Apparatus for cleaning distributor in fluidized bed reduction furnace |
| KR101009021B1 (en) * | 2003-12-29 | 2011-01-17 | 주식회사 포스코 | Apparatus for cleaning distributor in fluidized bed reduction furnace |
| KR100778673B1 (en) * | 2005-12-26 | 2007-11-22 | 주식회사 포스코 | Apparatus for manufacturing molten irons |
-
1987
- 1987-10-27 JP JP26928787A patent/JPH0723493B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01111809A (en) | 1989-04-28 |
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