JPH01205014A - Smelting reduction method and apparatus thereof - Google Patents
Smelting reduction method and apparatus thereofInfo
- Publication number
- JPH01205014A JPH01205014A JP2858188A JP2858188A JPH01205014A JP H01205014 A JPH01205014 A JP H01205014A JP 2858188 A JP2858188 A JP 2858188A JP 2858188 A JP2858188 A JP 2858188A JP H01205014 A JPH01205014 A JP H01205014A
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- gas
- reduction
- smelting furnace
- blown
- 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
Links
- 238000003723 Smelting Methods 0.000 title claims abstract description 77
- 230000009467 reduction Effects 0.000 title claims abstract description 74
- 238000000034 method Methods 0.000 title claims abstract description 34
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 110
- 239000007789 gas Substances 0.000 claims abstract description 108
- 229910052742 iron Inorganic materials 0.000 claims abstract description 54
- 238000007664 blowing Methods 0.000 claims abstract description 49
- 239000002893 slag Substances 0.000 claims abstract description 47
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 45
- 239000001301 oxygen Substances 0.000 claims abstract description 45
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 45
- 238000002485 combustion reaction Methods 0.000 claims abstract description 36
- 230000008569 process Effects 0.000 claims abstract description 11
- 239000011261 inert gas Substances 0.000 claims abstract description 9
- 239000002184 metal Substances 0.000 claims description 48
- 229910052751 metal Inorganic materials 0.000 claims description 48
- 239000003575 carbonaceous material Substances 0.000 claims description 29
- 238000000926 separation method Methods 0.000 claims description 16
- 239000002994 raw material Substances 0.000 claims description 14
- 239000000843 powder Substances 0.000 claims description 9
- 230000005484 gravity Effects 0.000 claims description 8
- 238000002844 melting Methods 0.000 claims description 8
- 230000008018 melting Effects 0.000 claims description 8
- 230000003647 oxidation Effects 0.000 claims description 8
- 238000007254 oxidation reaction Methods 0.000 claims description 8
- 238000005261 decarburization Methods 0.000 claims description 7
- 239000003795 chemical substances by application Substances 0.000 claims description 5
- 238000012546 transfer Methods 0.000 abstract description 17
- 238000003756 stirring Methods 0.000 abstract description 13
- 239000000463 material Substances 0.000 abstract description 6
- 230000001590 oxidative effect Effects 0.000 abstract 1
- 239000012256 powdered iron Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 230000001603 reducing effect Effects 0.000 description 8
- 239000012159 carrier gas Substances 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 239000000155 melt Substances 0.000 description 5
- 238000011946 reduction process Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 229910001882 dioxygen Inorganic materials 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 239000011819 refractory material Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 101100243025 Arabidopsis thaliana PCO2 gene Proteins 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910000805 Pig iron Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Landscapes
- Manufacture Of Iron (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は炭材を燃料および還元材として用、鉄鉱石を
転炉型製錬炉内において溶融状態で還元する溶融還元法
及びその装置に関する。[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a smelting reduction method and apparatus for reducing iron ore in a molten state in a converter type smelting furnace using carbonaceous materials as fuel and reducing agent. .
［従来の技術］
溶融還元法は、高炉製銑法に代わるものであり、高炉製
銑法においては高炉の建設費が高く、広大な敷地が必要
であるという欠点を解消すべく、近年に至り開発された
ものである。[Prior art] The smelting reduction method is an alternative to the blast furnace pig iron making method, and has been developed in recent years in order to overcome the drawbacks of the blast furnace iron making method, such as the high cost of constructing a blast furnace and the need for a large site. It was developed.
この還元法においては、鉄鉱石は製錬からの排ガスで予
備還元され、炭材、造滓材とともに製錬炉内に装入され
、また酸素ガスまたは攪拌用ガスが前記製錬炉内に吹き
込まれる。こうして炭材が、予め装入されである溶銑に
溶解されるとともに、炭材のＣが酸素ガスによって酸化
される。このときの酸化熱によって鉱石が溶融されると
ともに、鉱石が炭材中のＣによって還元される。溶銑か
ら発生するＣｏガスは過剰に吹き込まれる酸素ガスによ
り２次燃焼されてＣＯ２ガスになる。このＣＯ２ガスの
ｍ熱は、溶銑上を覆っているスラグまたはフォーミング
状の粒鉄に伝達され、次いで溶銑に伝達される。こうし
て、鉄鉱石が還元されて溶銑が製造されるが、製錬炉に
おける還元工程を軽減するため、製錬炉に装入される前
の鉄鉱石の予備還元率を６０％乃至７５％ととし、従っ
て製錬炉の排出ガスは還元性の高い低酸化度のガスを多
量に使用している。（例えば特公昭６１−４３４０６
）［発明が解決しようとする課題］
しかしながら、製錬炉における還元工程を軽減するため
、製錬炉に装入される前の鉄鉱石の予備還元率を３０％
超にする場合には、製錬炉の排出ガスの酸化度 ［（Ｈ
ｚＯ＋Ｃ０２）／（Ｉｈ＋Ｈ２０＋ＣＯ＋Ｃ０２）］以
下、これを単にＯＤと略記するコを下げる必要がある。In this reduction method, iron ore is pre-reduced with exhaust gas from smelting and charged into a smelting furnace together with carbon and slag materials, and oxygen gas or stirring gas is blown into the smelting furnace. It will be done. In this way, the carbonaceous material is dissolved in the previously charged hot metal, and the carbon in the carbonaceous material is oxidized by the oxygen gas. The ore is melted by the heat of oxidation at this time, and the ore is reduced by C in the carbonaceous material. Co gas generated from hot metal is subjected to secondary combustion by excessively blown oxygen gas and becomes CO2 gas. The heat of this CO2 gas is transferred to the slag or forming iron granules covering the hot metal, and then to the hot metal. In this way, iron ore is reduced to produce hot metal, but in order to reduce the reduction process in the smelting furnace, the preliminary reduction rate of the iron ore before being charged into the smelting furnace is set at 60% to 75%. Therefore, the exhaust gas from the smelting furnace uses a large amount of highly reducing gas with a low oxidation degree. (For example, Tokuko Sho 61-43406
) [Problem to be solved by the invention] However, in order to reduce the reduction process in the smelting furnace, the preliminary reduction rate of iron ore before being charged into the smelting furnace is set to 30%.
If the oxidation degree of the exhaust gas from the smelting furnace [(H
zO+C02)/(Ih+H20+CO+C02)] Hereinafter, this will be simply abbreviated as OD.
こうすると前記排ガス量は必然的に増加することになり
（例えば特公昭６ｌ−４３４０６） 、前記製錬炉の発
生エネルギーはＩ Ｇｃａｌ／Ｔ （溶銑）を大きく超
えることになり、製造所内のエネルギーバランス上発生
エネルギーが過剰になる。このことは当然製造コス小の
増大につながる。In this case, the amount of exhaust gas will inevitably increase (for example, Japanese Patent Publication No. 6L-43406), and the energy generated by the smelting furnace will greatly exceed I Gcal/T (hot metal), which will affect the energy balance within the factory. The upper energy generated becomes excessive. This naturally leads to an increase in manufacturing costs.
また、高い予備還元率を得るためには上記の通りＯＤの
低い排出ガスを必要とし、かつ鉄鉱石の予（ＡＨＵ元炉
内の滞留時間を長くすることになって、予備還元された
鉄鉱石の製錬炉内への装入と製造される溶銑の出湯サイ
クルとのバランスをとることが難しい。このことは必然
的に製錬炉の自由度を大きく制限する。In addition, in order to obtain a high pre-reduction rate, exhaust gas with a low OD is required as described above, and the residence time of the iron ore (pre-reduced iron ore) in the AHU main furnace is lengthened. It is difficult to balance the charging of hot metal into the smelting furnace with the tapping cycle of the produced hot metal.This inevitably greatly limits the flexibility of the smelting furnace.
また、鉄鉱石のスラグ中での溶解速度を上げ鉄鉱石の還
元処理速度を向上させるため、炉内のＣｏガスを２次燃
焼させ、その熱を利用するという方法が考えられ、従来
でも炉上部壁から２次燃焼用０２ガスを吹き込む方法が
とられている。しかし従来では２次燃焼比をあげると排
ガス温度は上昇するものの、排ガス顕熱を溶湯へ伝達す
る技術がなく、この結果、着熱効率が低下し、高温排ガ
スを排出せざるをえない、そしてこのような高温排ガス
は炉内壁耐火物を激しく損耗させるという大きな問題が
あり、このため２次燃焼比はあまりあげられないという
のが一般的な考え方であった。In addition, in order to increase the dissolution rate of iron ore in slag and improve the reduction processing speed of iron ore, a method of secondary combustion of Co gas in the furnace and use of the heat has been considered. The method used is to blow 02 gas for secondary combustion through the wall. However, in the past, although increasing the secondary combustion ratio raised the exhaust gas temperature, there was no technology to transfer the sensible heat of the exhaust gas to the molten metal, and as a result, the heat transfer efficiency decreased and high temperature exhaust gas had to be discharged. There is a big problem that such high-temperature exhaust gas severely wears out the refractories inside the furnace, and the general idea was that for this reason the secondary combustion ratio could not be increased very much.
さらに、精錬炉から排出される高温のガスまたは鉄鉱石
の利用は、溶融還元法において、エネルギーの低減また
は鉄鉱石の歩留まりの向上に関して、重要な問題となっ
ている。 この発明はかかる問題点を解決するためにな
されたものであって、溶銑またはスラグへの着熱効率を
高めて前記製錬炉からの発生エネルギーを抑え、製鉄所
全体のエネルギー効率を向上させる、掻業性の良好な溶
融還元法を提供しようするものである。Furthermore, the use of hot gas or iron ore discharged from a smelting furnace is an important issue in the smelting reduction process with regard to energy reduction or improvement of iron ore yield. This invention was made in order to solve this problem, and it improves the efficiency of heat transfer to hot metal or slag, suppresses the energy generated from the smelting furnace, and improves the energy efficiency of the entire steelworks. The purpose is to provide a melt reduction method with good commercial efficiency.
［課趙を解決するための手段及び作用コ以上のような問
題点について、本発明者等は溶融還元のメカニズム及び
これに対応した具体的な手段について検討を重ねたもの
でありこの結果、次のような事実を見出した。[Means and effects for solving the problem] Regarding the above-mentioned problems, the present inventors have repeatedly studied the mechanism of melt reduction and specific measures corresponding thereto, and as a result, the following I found a fact like this.
■上述したように、従来では着熱効率向上に対る技術的
限界や耐火物の損耗の面で２次燃焼比を大きく上げられ
ないというのが基本的な考え方であるが、２次燃焼を主
としてスラグ中で生じさせるよう０２を吹き込み、かつ
スラグを強攪拌することにより、高２次燃焼を確保しつ
つ着熱効率を効果的に窩めることが出来る。このような
高２次燃焼、高着熱効率により、スラグ及びスラグ中の
鉄鉱石の温度が高くなり、
Ｆｅ２０３ ＋３Ｃ−＋２Ｆｅ＋３ＣＯで表される９−
（溶湯中のＣ）による鉄鉱石の還元速度を効果的に高め
ることが出来る。■As mentioned above, the basic idea is that it is not possible to significantly increase the secondary combustion ratio due to technical limitations in improving heat transfer efficiency and wear and tear on refractories. By blowing 02 into the slag and strongly stirring the slag, it is possible to effectively improve heat transfer efficiency while ensuring high secondary combustion. Due to such high secondary combustion and high heat transfer efficiency, the temperature of the slag and the iron ore in the slag becomes high, and 9- expressed as Fe203 +3C-+2Fe+3CO
The rate of reduction of iron ore by (C in the molten metal) can be effectively increased.
■従来法では、還元処理の一時期または全期間、酸素の
底吹きを行っている例があるが、このような酸素の底吹
きは２次燃焼に有害である。即ち、酸素を底吹きすると
溶湯中で大量のＣＯガスを生じさせて溶湯を強攪拌し、
この結果、溶湯スプラッシュが２次燃焼域に達し、溶湯
中Ｃが酸素と反応することにより２次燃焼が阻害される
。したがって還元期間の一部または全部を問わず、酸素
を底吹きすることは避ける必要がある。(2) In conventional methods, there are examples in which bottom blowing of oxygen is carried out during a period or the entire period of the reduction process, but such bottom blowing of oxygen is harmful to secondary combustion. That is, when oxygen is blown from the bottom, a large amount of CO gas is generated in the molten metal, and the molten metal is strongly stirred.
As a result, the molten metal splash reaches the secondary combustion region, and the C in the molten metal reacts with oxygen, thereby inhibiting secondary combustion. Therefore, it is necessary to avoid bottom-blowing oxygen during part or all of the reduction period.
本発明は、このような知見にもとすき、次のような条件
を規定し、これにより高い処理速度での還元処理を可能
ならしめたものである。In view of this knowledge, the present invention stipulates the following conditions, thereby making reduction processing possible at a high processing speed.
（イ）攪拌ガスの底吹きと横吹きの組み合わせにより、
溶湯をスラグ中の鉄鉱石の存在する領域に積極的に拡散
させ、溶湯中のＣによる鉄鉱石の還元作用を促進させる
。(b) By combining bottom blowing and side blowing of stirring gas,
The molten metal is actively diffused into the region where iron ore exists in the slag, and the reduction action of the iron ore by C in the molten metal is promoted.
（ロ）所定レベル以上の２次燃焼比が得られるよう、脱
炭用酸素とは別に２次燃焼用酸素の吹き込みを行う。そ
して、この２次燃焼用酸素を上吹きランスからスラグ中
に吹き込んで２次燃焼頒域をスラグ中に形成させ、且つ
横吹きガスによりスラグを強攪拌し、２次燃焼により生
じた熱を鉄鉱石に着熱させる。(b) Oxygen for secondary combustion is blown separately from oxygen for decarburization so that a secondary combustion ratio of a predetermined level or higher is obtained. Then, this secondary combustion oxygen is blown into the slag from the top blowing lance to form a secondary combustion zone in the slag, and the slag is strongly stirred by the side blowing gas, and the heat generated by the secondary combustion is transferred to the iron ore. Heat the stone.
（ハ）溶湯中Ｃによる還元作用及び上吹き酸素による２
次燃焼が阻害されないようにするため、横吹きガス及び
底吹きガスはＣＯまたは不活性ガスとし、酸素は使わな
い。(c) 2 due to reduction action by C in the molten metal and top-blown oxygen
In order to prevent the subsequent combustion from being inhibited, CO or an inert gas is used as the side-blown gas and bottom-blown gas, and oxygen is not used.
これに加えて本発明によ溶融還元法は製錬炉に装入され
る鉄鉱石は予熱予備還元炉により予熱、予ｆｄｔｌｆｆ
１元され、さらに、前記予熱予備還元炉からキャリオー
バーされた鉄鉱石を回収することにより、熱効率または
生産効率を高めることが出来る。In addition, in the smelting reduction method according to the present invention, the iron ore charged into the smelting furnace is preheated and prefdtlff in a preheating prereduction furnace.
Thermal efficiency or production efficiency can be improved by recovering the iron ore that has been carried over from the preheating pre-reduction furnace.
すなわち、この発明による溶融還元法は、鉄鉱石を流動
層型の予熱予備還元炉で予熱、予備還元し、炭材、造滓
剤とともに精練炉に装入し、先端がスラグ層の上面乃至
下面付近のレベルにある上吹き酸素ランスより脱炭用酸
素および二次燃焼用酸素を吹き込むとともに、底吹き羽
口から不活性ガス、ＣＯｌまたはプロセスガス（この発
明を実施する溶融還元装置により発生するガスをいう、
以下同じ）を吹き込み、かつ前記底吹き羽口から吹きこ
まれたガスにより盛りあがった溶湯に向けて、横吹き羽
口から不活性ガス、ＣＯｌまたはプロセスガスを吹き込
む溶融還元方法であって、（１）前記予熱予備還元炉に
導入される前記製錬炉の排ガス温度を３００℃乃至１３
００℃、（２）前記製錬炉で発生するガスの酸化度［（
Ｈ２０＋Ｃ０ｚ）／（＋ｈ＋ＩｈＯ＋ＣＯ＋Ｃ０ｚ）コ
を０．５乃至１．０（３）予熱予備還元炉における予備
還元率を３０％以下、とし、前記予熱予備還元炉からキ
ャリオーバーされた鉱石を排ガスと分離して、前記予熱
予備還元炉または前記製錬炉に装入することを特徴とす
る。That is, in the smelting reduction method according to the present invention, iron ore is preheated and prereduced in a fluidized bed type preheating prereduction furnace, and then charged into a smelting furnace together with carbonaceous material and slag forming agent, so that the tip of the iron ore is placed between the upper surface and the lower surface of the slag layer. Oxygen for decarburization and oxygen for secondary combustion are blown from the top blowing oxygen lance located at a nearby level, and inert gas, COI or process gas (gas generated by the smelting reduction equipment implementing this invention) is blown from the bottom blowing tuyere. means,
The same applies hereinafter) is blown into the molten metal, and an inert gas, COI or a process gas is blown from the side blowing tuyere into the molten metal which has risen due to the gas blown from the bottom blowing tuyere, the method comprising: (1) ) The temperature of the exhaust gas from the smelting furnace introduced into the preheating preliminary reduction furnace is 300°C to 13°C.
00°C, (2) degree of oxidation of the gas generated in the smelting furnace [(
H20 + COz) / (+h + IhO + CO + COz) 0.5 to 1.0 (3) The preliminary reduction rate in the preheating pre-reduction furnace is 30% or less, and the ore carried over from the preheating pre-reduction furnace is separated from the exhaust gas. , it is characterized in that it is charged into the preheating preliminary reduction furnace or the smelting furnace.
かくして前記製錬炉からの発生エネルギーは製造される
溶鉄トン当たり１Ｇｃａｌ程度に抑えられ、製鉄所のプ
ロセス全体のエネルギー効率が向上する。In this way, the energy generated from the smelting furnace is suppressed to about 1 Gcal per ton of molten iron produced, improving the energy efficiency of the entire process of the steel mill.
この発明による溶融還元装置は鉱石を流動層型の予熱予
備還元炉で予熱、予備還元し、炭材、造滓剤とともに、
製錬炉に装入し、上吹き酸素ランスより脱炭用酸素およ
び二次燃焼用酸素を吹き込む溶融還元装置であって、前
記製錬炉の炉底または側壁に設けられ、不活性ガス、ｃ
ｏ、またはプロセスガスを吹き込む羽口と、前記製錬炉
の排ガスから粉体を分離する第１の分離装置と、前記予
熱予備還元炉の排ガスから粉体を分離する第２の分離装
置と、前記第２の分離装置の排ガスにより原料供給装置
から導入される鉱石を予熱する予熱装置と、前記予熱装
置の排ガスから微粉の鉱石を分離する第３の分離装置と
、を具備することを特徴とする。The smelting reduction apparatus according to the present invention preheats and pre-reduces ore in a fluidized bed type preheating pre-reduction furnace, and then, together with carbonaceous material and slag-forming agent,
A smelting reduction device that is charged into a smelting furnace and blows oxygen for decarburization and oxygen for secondary combustion from a top-blown oxygen lance, and is provided at the bottom or side wall of the smelting furnace, and is equipped with an inert gas, c
o, or a tuyere into which process gas is blown, a first separation device that separates powder from the exhaust gas of the smelting furnace, and a second separation device that separates the powder from the exhaust gas of the preheating pre-reduction furnace; It is characterized by comprising a preheating device that preheats the ore introduced from the raw material supply device using the exhaust gas of the second separation device, and a third separation device that separates fine ore from the exhaust gas of the preheating device. do.
［実施例］ 本発明の実施例を添付の図面を参照しながら説明する。[Example] Embodiments of the invention will be described with reference to the accompanying drawings.
第１図は本発明の溶融還元法に用いられるプロセスの説
明図である。製錬炉１０内には鉄浴１１及びスラグ層１
２が形成され、副原料である炭材及び造滓剤が装入され
る第１のシュート１４が前記製錬炉の上部に設けられて
おり、上吹き酸素ランス２１が炉内に鉛直に挿入される
。前記ランスには脱炭用酸素（ＰＣＯ２）、２次燃焼用
（ＤＣＯ２）の酸素をそれぞれ噴出するノズル２２．２
３が設けられ、さらにランス先端の中心部には主に炭材
または石灰等の副原料を吹き込むノズル２４が設けられ
ている。また、製錬炉１０の側壁と炉底にはそれぞれ攪
拌用ガスを吹き込む横吹き羽口２５、底吹き羽口２６が
設けられ、これらの羽口からキャリアーガスとともに粉
状の鉄鉱石または炭材を吹きこむための混合、圧送手段
として加圧装置２７．２８が設けられている。FIG. 1 is an explanatory diagram of the process used in the melt reduction method of the present invention. Inside the smelting furnace 10 there is an iron bath 11 and a slag layer 1.
A first chute 14 is provided at the top of the smelting furnace, and a first chute 14 is provided at the top of the smelting furnace, and a top blowing oxygen lance 21 is inserted vertically into the furnace. be done. The lance has a nozzle 22.2 that spouts oxygen for decarburization (PCO2) and oxygen for secondary combustion (DCO2), respectively.
3 is provided, and furthermore, a nozzle 24 is provided in the center of the tip of the lance, which mainly blows auxiliary raw materials such as carbonaceous material or lime. In addition, a side blowing tuyere 25 and a bottom blowing tuyere 26 are provided on the side wall and the bottom of the smelting furnace 10, respectively, for blowing stirring gas into them, and powdered iron ore or carbonaceous material is discharged from these tuyeres together with carrier gas. Pressurizing devices 27 and 28 are provided as mixing and pressure feeding means for blowing.
製錬炉１０の上方には原料である鉄鉱石、副原料である
炭材及び造滓剤等がよく知られた通常の原料供給装置（
簡明のため特に図示せず）もしくは後に説明する予熱予
備還元炉３０から自然落下により製錬炉に装入される原
料用シュート１４及び製錬炉からの排ガスが排出される
排ガス用導管１５が設けられている。前記導管１５から
排出された排ガス中に含まれるダストを除去する第１の
分離装置１６と、前記排ガス及び鉱石が導入されてこれ
を予熱、予備還元する流動層型の予熱予備還元炉３０と
、前記予熱予備還元炉３０からの排ガスを受けてこれに
含まれる鉄鉱石の微粒を除去する第２の分離装置３５と
、前記第２の分離装置３５からの排ガスと前記原料供給
装置から鉄鉱石が導入されて前記鉄鉱石を予熱する予熱
装置４０と、前記予熱装置４０からの排ガスから鉄鉱石
の細粒を除去する第３の分離装置４５と、が設けられて
いる。前記第２、第３の分離装置から分離された鉄鉱石
の細粒または粉体はＡｒ、Ｎ２等のキャリアーガスとと
もに混合、かつ加圧され、製錬炉の側壁及び炉底にそれ
ぞれ設けられた横吹き羽口２５または底吹き羽口２６の
いずれか一方または双方に圧送される。この場合、混合
、加圧の手段として加圧装置２７．２８が設けられてい
る。Above the smelting furnace 10, a well-known ordinary raw material supply device (
For the sake of brevity, a raw material chute 14 is charged into the smelting furnace by gravity from a preheating pre-reduction furnace 30 which will be explained later, and an exhaust gas conduit 15 is provided through which exhaust gas from the smelting furnace is discharged. It is being a first separation device 16 for removing dust contained in the exhaust gas discharged from the conduit 15; a fluidized bed preheating pre-reduction furnace 30 into which the exhaust gas and ore are introduced and preheating and pre-reducing them; A second separator 35 receives the exhaust gas from the preheating pre-reduction furnace 30 and removes iron ore particles contained therein, and a second separator 35 receives the exhaust gas from the preheating pre-reduction furnace 30 and removes iron ore particles from the exhaust gas from the second separator 35 and the raw material supply device. A preheating device 40 is introduced to preheat the iron ore, and a third separation device 45 is provided to remove iron ore fines from the exhaust gas from the preheating device 40. The iron ore fine grains or powder separated from the second and third separators are mixed and pressurized with a carrier gas such as Ar and N2, and are installed on the side wall and bottom of the smelting furnace, respectively. The air is fed under pressure to either one or both of the side blowing tuyere 25 and the bottom blowing tuyere 26 . In this case, pressurizing devices 27, 28 are provided as mixing and pressurizing means.
以上のように構成された溶融還元装置を用いる溶融還元
法について説明する。原料である鉄鉱石は上記供給装置
から予熱装置４０に入り、ここで予熱された後、予熱予
備還元炉の装入口３４から予熱予備還元炉に装入され、
ここで予熱、予備還元された鉄鉱石は予熱予備還元炉の
出口３１から原料用シュート１４を経て重力落下により
製錬炉１０に装入される。A melt reduction method using the melt reduction apparatus configured as described above will be explained. Iron ore, which is a raw material, enters the preheating device 40 from the above-mentioned supply device, is preheated here, and then charged into the preheating prereduction furnace from the charging port 34 of the preheating prereduction furnace,
The preheated and prereduced iron ore is charged into the smelting furnace 10 by falling by gravity from the outlet 31 of the preheating and prereduction furnace through the raw material chute 14.
炉内への装入物と吹き込みガスとの反応は後に詳述する
が、炉内では溶湯による鉄浴１１とスラグ層１２が形成
される。製錬炉１０で発生し排ガスは排ガス用導管１５
を通って第１の分離装置１６でダストが除去された後、
流動層型の予熱予備還元炉３０に導入されて流動ガスと
して働き、前述の通り予熱予備還元炉３０に装入された
鉄鉱石が予熱、予＠還元される。予熱予備還元炉からの
排ガスは第２の分離装置３５に入りここで細粒もしくは
粉状の鉱石が分離された後、通常の排ガス処理装置を経
て排出されるか、もしくは羽口２５．２６の粉体吹き込
みのキャリアーガスとして用いられる。さらにこの排ガ
スはガス導管１５に導入されて製錬炉からの排ガスに混
合され、予熱予備還元炉に導入されるガスの温度調節に
使用することも可能である。前記ガスの温度は３００℃
未満では予熱、予備還元の効果が期待出来ず、１３００
℃超では設備の耐熱性または鉄鉱石のスティッキングに
問題が出てくる。The reaction between the charge into the furnace and the blown gas will be described in detail later, but an iron bath 11 and a slag layer 12 are formed by the molten metal in the furnace. The exhaust gas generated in the smelting furnace 10 is passed through the exhaust gas conduit 15
After the dust is removed in the first separator 16 through
The iron ore is introduced into the fluidized bed type preheating pre-reducing furnace 30 and acts as a fluidizing gas, and as described above, the iron ore charged into the preheating pre-reducing furnace 30 is preheated and pre-reduced. The exhaust gas from the preheating pre-reduction furnace enters a second separator 35 where the fine or powdered ore is separated and is then discharged through a conventional exhaust gas treatment device or through the tuyere 25.26. Used as a carrier gas for powder blowing. Furthermore, this exhaust gas can also be introduced into the gas conduit 15, mixed with the exhaust gas from the smelting furnace, and used to adjust the temperature of the gas introduced into the preheating pre-reduction furnace. The temperature of the gas is 300℃
If it is less than 1300, the effect of preheating and preliminary reduction cannot be expected.
If the temperature exceeds ℃, there will be problems with the heat resistance of the equipment or the sticking of iron ore.
前記第２の分離装置で分離された細粒もしくは粉状の粉
の鉄鉱石は一部は予熱予備還元炉に戻されその残余は単
味もしくは粉炭材と混合されて加圧装置２７．２８に送
られ、ここでキャリアガスと混合された後、加圧されて
羽口２５．２６または上吹き酸素ランス２１の専用ノズ
ル２４に送られ、ここから製錬炉に吹き込まれる。また
、前記第３の分離装置４５で分離された細粒もしくは粉
状の鉄鉱石は大部分、予熱予備還元炉を経ていないので
すべて予熱予備還元炉に戻される。Part of the fine or powdered iron ore separated in the second separator is returned to the preheating pre-reduction furnace, and the remainder is mixed with plain or powdered carbon material and sent to the pressurizing device 27.28. After being mixed with carrier gas, it is pressurized and sent to the tuyeres 25, 26 or the dedicated nozzle 24 of the top-blowing oxygen lance 21, from where it is blown into the smelting furnace. Furthermore, most of the fine grain or powdered iron ore separated by the third separator 45 does not pass through the preheating pre-reducing furnace, so it is all returned to the preheating pre-reducing furnace.
上記原料供給装置から供給される塊状もしくは粗粒の副
原料である炭材または造滓剤は原料用シュート１４から
自然落下により製錬炉１０に装入されるが、粉状のもの
については、種々テストを重ねた結果まとめて一度に投
入することにより飛散せず、炉内に装入されることを知
、見し、さらに塊状のものと一緒に投入するとさらに効
果的であることを見出した。そこで、第２または第３の
分離装置から分離された高温の粗粒及び粉状の鉄鉱石を
混合し、または塊状及び粉状の炭材を混合して、原料用
シュート１４から重力追上により装入して好成績を収め
ている。また、前記高温の粉状の鉄鉱石を予熱予備還元
炉へ戻すかまたは同じく粉状の炭材と混合して、羽口２
５、羽口２６またはノズル２４から炉内にキャリアーガ
スとともに吹き込むことも、歩留まりを向上させる上で
好ましいことである。The coal material or slag-forming agent, which is a lumpy or coarse-grained auxiliary raw material supplied from the raw material supply device, is charged into the smelting furnace 10 by gravity falling from the raw material chute 14, but in the case of powder, As a result of various tests, they found that by charging all at once, they could be charged into the furnace without scattering, and they also discovered that it is even more effective if they are charged together with lumps. . Therefore, the high-temperature coarse grains and powdered iron ore separated from the second or third separator are mixed, or the lumpy and powdery carbonaceous materials are mixed, and the mixture is passed through the raw material chute 14 by gravity. I've been using it and getting good results. In addition, the high-temperature powdered iron ore is returned to the preheating pre-reduction furnace or mixed with the same powdered carbonaceous material, and the tuyere 2
5. It is also preferable to blow the carrier gas into the furnace from the tuyere 26 or nozzle 24 in order to improve the yield.
次いで、製錬炉内べのガス吹き込みと炉内反応との関係
について、第２図乃至第７図を参照しながら詳しく説明
する。第２図は第１図における吹き込みガスの挙動を模
式的に示したものである。Next, the relationship between gas injection into the smelting furnace and the reaction within the furnace will be explained in detail with reference to FIGS. 2 to 7. FIG. 2 schematically shows the behavior of the blown gas in FIG. 1.
還元処理中は、その初期から終期に至るまで上吹きラン
ス２１、横吹き羽口２５及び横吹き羽口２６からガスの
吹き込みが行われる６羽口２５．２６からのガス吹き込
みは、両者の協働作用により溶湯をスラグ中に拡散させ
、還元速度を飛躍的に高める効果をもたらす。During the reduction process, gas is blown from the top blowing lance 21, side blowing tuyere 25, and side blowing tuyere 26 from the initial stage to the final stage. The action causes the molten metal to diffuse into the slag, resulting in the effect of dramatically increasing the reduction rate.
前述したように、本発明者等はスラグ層１２の鉄鉱石は
、大部分溶湯中のＣを還元物質として進行するという事
実を解明し、これに基づき溶湯を強攪拌してスラグ層（
鉄鉱石が浮遊する領域）中に積極的に拡散させて還元速
度を高めようというものである。このため本発明は、底
吹き羽口２６から攪拌ガスを供給して溶湯面に***部（
Ａ）を形成し、同時に、横吹き羽口２５がらガス流の少
なくとも一部が上記溶湯***部（Ａ）に当たるようにし
て攪拌ガスを供給するものであり、この横吹きガスによ
り溶湯***部（Ａ）の溶湯がスラグ中に飛散することに
なる。スラグの見掛は比重は通常０．１〜０．５で、一
方鉄鉱石の嵩比重は１〜３であり、従ってスラグ中の鉄
鉱石は、スラグ下部領域に集中して浮遊している。As mentioned above, the present inventors have elucidated the fact that most of the iron ore in the slag layer 12 progresses using C in the molten metal as a reducing substance, and based on this, the molten metal is strongly stirred to form the slag layer (
The idea is to actively diffuse iron ore into the area (where iron ore is suspended) to increase the rate of reduction. Therefore, in the present invention, stirring gas is supplied from the bottom blowing tuyere 26 to form protuberances (
A), and at the same time, a stirring gas is supplied from the side blowing tuyere 25 so that at least a part of the gas flow hits the molten metal bulge (A), and this side blown gas blows the molten metal bulge (A). The molten metal in A) will be scattered into the slag. The apparent specific gravity of slag is usually 0.1 to 0.5, while the bulk specific gravity of iron ore is 1 to 3, so the iron ore in the slag is concentrated and suspended in the lower region of the slag.
上記のように溶湯***部を横吹きガスで飛散させると、
この飛散溶湯は、鉄鉱石が存在するスラグ層１２の下部
領域に拡散し、この拡散溶湯中のＣが鉄鉱石を還元し、
高い還元速度が得られる。When the molten metal protrusions are scattered with side-blown gas as described above,
This scattered molten metal diffuses into the lower region of the slag layer 12 where iron ore exists, and C in this diffused molten metal reduces the iron ore,
High reduction rate can be obtained.
このような効果を得るためには横吹きガスが製錬炉の上
下方向及び水平方向において成るべく正確に上記溶湯隆
起部（Ａ）に当たるようにすることが好ましく、水平方
向においては第３図（ａ）。In order to obtain such an effect, it is preferable that the side-blown gas hits the molten metal protrusion (A) as accurately as possible in the vertical and horizontal directions of the smelting furnace. a).
及び（ｂ）に示すような位置関係で羽口２５．２６を設
けることが好ましい、また、底吹き及び横吹きとも比較
的多量のガスを吹き込み、強攪拌を行う必要があること
は言うまでもないが、その吹き込みガス量は溶湯量、溶
湯深さ等に応じて決定される。横吹きガスは、上述した
ような溶湯の拡散作用に加え、２次燃焼領域が形成され
るスラグの攪拌をも行うものであり、これについては後
述する。It is preferable to provide the tuyeres 25 and 26 in the positional relationship shown in (b), and it goes without saying that both bottom blowing and side blowing require blowing a relatively large amount of gas and performing strong stirring. The amount of blown gas is determined depending on the amount of molten metal, the depth of molten metal, etc. In addition to the above-mentioned molten metal diffusion effect, the side-blown gas also stirs the slag in which the secondary combustion region is formed, and this will be described later.
本発明で使用される横吹きガス及び底吹きガスは、不活
性ガス（Ｎ２．Ａｒ等）、ｃｏまたはプロセスガスに限
定され、０２は使用されない、これは次のような理由に
よる。The side-blown gas and bottom-blown gas used in the present invention are limited to inert gases (N2, Ar, etc.), co, or process gases, and 02 is not used for the following reason.
先ず、横吹きガスに０２を用いると、鉄鉱石還元のため
に飛散させた溶湯中のＣによる還元作用を阻害してしま
うという基本的な問題がある。加えて酸素を使用した場
合、耐火物の温度が上昇し、耐火物の損耗という問題を
生じる。また、底吹きガスに酸素を用いると、上述した
ように溶湯中で大量のＣｏガスを生じさせて溶湯を強攪
拌し過ぎ、この結果、溶湯のスプラッシュが２次燃焼領
域（第２図参照）に達し、溶湯中Ｃが後述する２次燃焼
用酸素と反応して２次燃焼が阻害されてしまう、加えて
、酸素を使用すると底吹き羽口なと耐火物の温度が上が
り過ぎるため冷却ガス（Ｃ３Ｈ８）を添加する必要があ
り、これも底吹きガス量を増大させ、強攪拌→溶湯スプ
ラッシュの発生を過大に助長することになる。第４図は
、Ｎ２底吹きを行う本発明と、Ｎ２に代え０２吹き込み
を行った比較例について、設定したＯ Ｄ ［Ｐ ＣＯ
２／ （Ｄ ＣＯＺ＋鉱石中ｏ２＋炭材中０２＋原料付
着水十
炭材中水案分（１／２） ）コに対す
る実際のＯＤ（実測）を調べた結果を示すもので、０２
底吹きにより２次燃焼が阻害されていることが示されて
いる。First, when 02 is used as a side-blown gas, there is a fundamental problem in that it inhibits the reducing action of C in the molten metal that is scattered to reduce iron ore. In addition, when oxygen is used, the temperature of the refractory increases, causing the problem of wear and tear of the refractory. Furthermore, when oxygen is used as the bottom blowing gas, as mentioned above, a large amount of Co gas is generated in the molten metal and the molten metal is agitated too strongly, resulting in the molten metal splashing in the secondary combustion region (see Figure 2). The carbon in the molten metal reacts with the oxygen for secondary combustion, which will be described later, and the secondary combustion is inhibited.In addition, when oxygen is used, the temperature of the refractories at the bottom blowing tuyeres rises too much, so cooling gas is required. It is necessary to add (C3H8), which also increases the amount of bottom-blown gas and excessively promotes the occurrence of strong stirring→molten metal splash. Figure 4 shows the set O D [P CO
2/ (D COZ + O2 in the ore + 02 in the carbon material + water adhering to the raw material + water proportion in the carbon material (1/2)) This shows the results of investigating the actual OD (actual measurement) for 02
It has been shown that secondary combustion is inhibited by bottom blowing.
なお、攪拌ガスである不活性ガス（Ｎ２ 、 Ａｒ等）
、ＣＯまたはプロセスガスは、単独または混合して使用
することが出来る。In addition, an inert gas (N2, Ar, etc.) as a stirring gas
, CO or process gases can be used alone or in combination.
本発明では、２次燃焼領域を主としてスラグ内に形成さ
せつつ高２次燃焼を実現させるものであり、このように
２次燃焼領域をスラグ内に形成しかつ横吹きガスによっ
てスラグを強攪拌することにより、高２次燃焼を確保し
つつ高い着熱効率を得ることが出来る。したがって、上
記２次燃焼用酸素は、主としてスラグ内に形成されるよ
うスラグ中に吹き込まれることが必要である。In the present invention, high secondary combustion is realized while forming the secondary combustion region mainly within the slag.In this way, the secondary combustion region is formed within the slag and the slag is strongly agitated by the side-blown gas. By doing so, it is possible to obtain high heat transfer efficiency while ensuring high secondary combustion. Therefore, the secondary combustion oxygen needs to be blown into the slag so that it is mainly formed within the slag.
具体的には上吹きランスの高さがスラグや溶湯レベルに
対し適度なレベルに設定されることが必要である。すな
わち、上吹きランス２１はそのノズル孔高さをスラグ面
上方あるいはスラグ面下とすることができるが、その高
さが高過ぎると２次燃焼領域がスラグ内に形成されなく
なって、着熱効率が低下するという問題があり、またラ
ンス高さが低過ぎると２次燃焼領域が適正に形成されな
い虞がある他、ランス２１への地金付着、ランス損傷に
よる水漏れの虞がある。上記ランス高さの適度なレベル
設定には、前記スラグが５０〜５００ｋｇ／ を程度、
スラグレベルで１ｍ以上必要である。スラグが少ない場
合に低すぎるスラグレベルに合わせてランスを下げた場
合、ランスからの酸素ジェットが鉄浴面に衝突して、飛
散された粒鉄中のＣの影響で炉内ガスのＯＤが低下する
ので問題がある。Specifically, the height of the top blowing lance must be set at an appropriate level relative to the slag and molten metal levels. That is, the height of the nozzle hole of the top blow lance 21 can be set above or below the slag surface, but if the height is too high, the secondary combustion region will not be formed in the slag, and the heat transfer efficiency will be reduced. Furthermore, if the lance height is too low, there is a risk that the secondary combustion region will not be formed properly, and there is also a risk of metal adhesion to the lance 21 and water leakage due to damage to the lance. To set the lance height at an appropriate level, the slag should be approximately 50 to 500 kg/
A slag level of 1 m or more is required. When the lance is lowered to match the slag level that is too low when there is little slag, the oxygen jet from the lance collides with the iron bath surface, and the OD of the furnace gas decreases due to the influence of carbon in the scattered iron particles. Therefore, there is a problem.
第５図はランス先端のスラグ面（フォーミングレベル）
からの高さと着熱効率との関係を示すもので、ランス高
さがスラグ面にたいして高過ぎると良好な熱効率が得ら
れなくなることが示されている。また、第６図は横吹き
ガス量と着熱効率との関係との関係を示すもので、横吹
きガスを大量に吹き込み、スラグ層を強攪拌することに
より良好な着熱効率が得られることが解る。Figure 5 shows the slug surface of the lance tip (forming level)
This shows the relationship between the height of the lance and the heat transfer efficiency, and shows that if the lance height is too high relative to the slag surface, good thermal efficiency cannot be obtained. In addition, Figure 6 shows the relationship between the amount of side-blown gas and heat transfer efficiency, and it can be seen that good heat transfer efficiency can be obtained by blowing a large amount of side-blown gas and stirring the slag layer strongly. .
本発明では高着熱効率が得られるため、ＯＤを上記のよ
うに高くすることにより高い還元速度が得られるが、こ
れに加え、ＯＤを上げることにより炭材〈主としてコー
クス）の添加量を低く抑えることか出来、この結果、炭
材の原単位を低減を図る゛ことができるとともに、溶湯
中のＰ成分の殆どが炭材により持ち込まれることから、
溶湯中のＰの低減を図ることができる。また、ＯＤが高
くなると、気化脱硫現象が活発になり、溶湯中のＳも低
下する。このような観点からも本発明ではＯＤは０．５
以上とする。ＯＤの上限は１．０であるが、ＯＤは大き
い程望ましい。In the present invention, a high heat transfer efficiency is obtained, so a high reduction rate can be obtained by increasing the OD as described above, but in addition to this, by increasing the OD, the amount of carbon material (mainly coke) added can be kept low. As a result, it is possible to reduce the unit consumption of carbonaceous materials, and since most of the P component in the molten metal is brought in by the carbonaceous materials,
It is possible to reduce P in the molten metal. Furthermore, when the OD increases, the vaporization desulfurization phenomenon becomes active, and S in the molten metal also decreases. From this point of view, in the present invention, the OD is 0.5.
The above shall apply. The upper limit of OD is 1.0, but a larger OD is more desirable.
第７図は第１表に示す炭材Ａを用いた場合の酸化度○Ｄ
と第１図の溶融還元装置から発生する余剰エネルギーと
の関係を示なグラフ図である。図中斜線で示した範囲が
製鉄所全体のエネルギーバランスを考えたときの適正な
余剰エネルギーの範囲である。この図は前記溶融還元装
置について検討した結果えられたもので、これによれば
、ＯＤが０．５より小さい場合は余剰エネルギーは多過
ぎて無駄なエネルギーが発生することになる。このこと
は第２図に示されているように予熱予備選率を３０％以
下にしたときに達成されるのであって、３０％より多く
することは前述の通り鉄鉱石の予熱予備還元炉の滞留時
間が長くなり、溶融還元装置の操業の自由度が大きく制
限されることになる。Figure 7 shows the oxidation degree ○D when carbon material A shown in Table 1 is used.
2 is a graph diagram showing the relationship between the amount of energy and the surplus energy generated from the melting reduction apparatus of FIG. 1. FIG. The shaded range in the figure is the appropriate range of surplus energy when considering the energy balance of the entire steelworks. This figure was obtained as a result of studying the above-mentioned melting reduction apparatus, and according to this figure, if the OD is smaller than 0.5, the surplus energy is too large and wasteful energy is generated. This is achieved when the preheating preselection rate is set to 30% or less as shown in Figure 2, and increasing it to more than 30% is achieved in the iron ore preheating prereduction furnace as described above. The residence time becomes longer, and the degree of freedom in the operation of the melt reduction apparatus is greatly restricted.
第８図は第１表に示す炭材Ｂを用いた場合の、第７図と
同様の酸化度ＯＤと余剰エネルギーとの関係を示すグラ
フ図である。炭材Ｂは炭材Ａよりも発熱量が大きいため
、ＯＤが小さい値でも上記エネルギーバランスに見合う
適正な余剰エネルギーとなっている０本発明の溶融還元
法では反応の性質上、炭材の粘結性、固定炭素等の物性
は問わない６したがって、炭材の選択範囲が広いことか
ら考えて、ＯＤの最適範囲は０．５乃至１．０である。FIG. 8 is a graph showing the relationship between oxidation degree OD and surplus energy, similar to FIG. 7, when carbon material B shown in Table 1 is used. Since carbonaceous material B has a larger calorific value than carbonaceous material A, even if the OD is small, it provides appropriate surplus energy that matches the above energy balance. Physical properties such as solidification and fixed carbon do not matter.6 Therefore, considering the wide selection range of carbon materials, the optimum range of OD is 0.5 to 1.0.
第 １ 表
上記に加えて本発明の特徴は予熱予備還元炉３０または
予熱装置４０の排ガスから細粒もしくは粉状の鉄鉱石を
分離して回収し、これを製錬炉に戻して鉄鉱石の歩留ま
りを向上させる。これによる効果を第９図及び第１０図
により説明する。Table 1 In addition to the above, the present invention is characterized by separating and recovering fine or powdered iron ore from the exhaust gas of the preheating pre-reduction furnace 30 or the preheating device 40, returning it to the smelting furnace, and converting it into iron ore. Improve yield. The effect of this will be explained with reference to FIGS. 9 and 10.
第９図は炭材原単位及び発生ガス量のＯＤによる変化を
示したグラフ図である。図中、点線、実線はそれぞれ鉄
鉱石の分離回収の前、後のグラフで、これに付した数字
は予備還元率である。これにより本発明による細粒もし
くは粉状の鉄鉱石を分離回収する効果は従来例と比較し
てＯＤが０．５の場合、炭材原単位及び発生ガス量はそ
れぞれ溶銑トン当たり１０ｋｇ、 １ＯＮｍ’の低下と
なって示されている。第１０図（ａ）、（ｂ）は縦軸は
何れも発生頻度指数、横軸はそれぞれ製錬炉１ｏの熱効
率、粗大粒鉄鉱石の混入による操業トラブルの頻度をと
って示したグラフ図である。これにより、上記分離回収
の効果は熱効率で１０％向上し、粗粒の混入によるノズ
ル２４または 羽口２５．２６の閉塞等による操業トラ
ブルは殆ど皆無となった。FIG. 9 is a graph showing changes in carbon material consumption rate and amount of generated gas depending on OD. In the figure, the dotted line and the solid line are graphs before and after the separation and recovery of iron ore, respectively, and the numbers attached to these are the preliminary reduction rate. As a result, the effect of separating and recovering fine or powdered iron ore according to the present invention is that when OD is 0.5 compared to the conventional example, the carbon material consumption rate and amount of gas generated are 10 kg and 1 ONm' per ton of hot metal, respectively. This is shown as a decrease in Figures 10 (a) and (b) are graphs in which the vertical axis shows the occurrence frequency index, and the horizontal axis shows the thermal efficiency of the smelting furnace 1o, and the frequency of operational troubles due to the contamination of coarse iron ore, respectively. be. As a result, the thermal efficiency of the separation and recovery was improved by 10%, and there were almost no operational troubles such as clogging of the nozzle 24 or tuyeres 25, 26 due to the incorporation of coarse particles.
次に本実施例に基づく具体的数値を挙げる。炭材として
石炭を１０７４ｋｇ／ＴＨＭ （製造される溶銑トン当
たり、以下同じ）、酸素を７９８／ＴＨＭを使用してＯ
Ｄが０．５１着熱効率は７０％であった。Next, specific numerical values based on this example will be listed. Coal was used as carbon material at 1074 kg/THM (per ton of hot metal produced, the same applies hereinafter), and oxygen was used at 798 kg/THM.
When D was 0.51, the heat transfer efficiency was 70%.
［発明の効果］
本発明によれば、上吹き酸素ランスの脱炭用、２次燃焼
用の酸素ノズルから、直接、スラグ層に酸素を吹きこみ
、また、製錬炉の炉壁及び炉底に設けた羽口からガス吹
き込みを行って強攪拌し、製錬炉の発生ガスの酸化度を
０．５乃至１．０に調整して前記ガスの温度を３００℃
とすることが出来るので、製錬炉の熱効率を向上させ同
時に溶融還元装置の余剰エネルギーバランスに見合った
適正なものとすることができる。また、予熱予備還元炉
の排ガスから細粒もしくは粉状の鉄鉱石を分離して前記
鉱石をキャリアーガスとともに前記羽口もしくは酸素ラ
ンスの専用ノズルから吹き込むので熱効率が向上し、粗
大粒混入による操業トラブルを解消することが出来る。[Effects of the Invention] According to the present invention, oxygen is blown directly into the slag layer from the oxygen nozzle for decarburization and secondary combustion of the top-blowing oxygen lance, and the furnace wall and bottom of the smelting furnace are Gas is injected through the tuyere provided in the smelting furnace for strong stirring, the oxidation degree of the gas generated in the smelting furnace is adjusted to 0.5 to 1.0, and the temperature of the gas is brought to 300°C.
Therefore, the thermal efficiency of the smelting furnace can be improved, and at the same time, it can be made appropriate for the surplus energy balance of the smelting reduction device. In addition, fine grained or powdered iron ore is separated from the exhaust gas of the preheating pre-reduction furnace and the ore is blown into the tuyere or oxygen lance with a carrier gas, improving thermal efficiency and causing operational problems due to coarse grains being mixed in. can be resolved.
第１図は本発明の溶融還元法に用いられる溶融還元装置
のプロセスの説明図、第２図は第１図における製錬炉内
のガス流れを示す模式図、第３図は横吹き羽口と底吹き
羽口との位置関係を示す説明図、第４図は設定ＯＤに対
する実測ＯＤを示すグラフ図、第５図はランス高さと着
熱効率の関係を示すグラフ図、第６図は横吹きガス量と
着熱効率との関係を示すグラフ図、第７図及び第８図は
は第１図の溶融還元装置から発生する余剰エエルギーと
ＯＤとの関係を示すグラフ図、第９図は炭材原単位及び
発生ガス量についてそれぞれＯＤとの関係を示すグラフ
図、第１０図は粉状の鉄鉱石を分離回収した場合の熱効
率の向上及び操業トラブルの減少を示すグラフ図である
。
１０・・・製錬炉、１１・・・鉄浴、１２・・・スラグ
層、１４・・・原料用シュート、１５・・・ガス導管、
１６・・・第１の分離装置、２１・・・酸素ランス、２
２．２３．２４ノズル、２５．２６・・・羽口、２７．
２８・・・加圧装置、３０・・・予熱予備還元炉、３５
・・・第２の分離装置、４０・・・予熱装置、４１・・
・切り替え弁、４２・・・閉止弁、４５・・・第３の分
離装置。Fig. 1 is an explanatory diagram of the process of the smelting reduction apparatus used in the smelting reduction method of the present invention, Fig. 2 is a schematic diagram showing the gas flow in the smelting furnace in Fig. 1, and Fig. 3 is a side blowing tuyere. Fig. 4 is a graph showing the measured OD against the set OD, Fig. 5 is a graph showing the relationship between lance height and heat transfer efficiency, and Fig. 6 is a graph showing the relationship between the lance height and the heat transfer efficiency. Graphs showing the relationship between gas amount and heat transfer efficiency, Figures 7 and 8 are graphs showing the relationship between surplus energy generated from the melting reduction device in Figure 1 and OD, and Figure 9 is a graph showing the relationship between the OD and the excess energy generated from the melting reduction device in Figure 1. FIG. 10 is a graph showing the relationship between the basic unit and the amount of gas generated and OD, and FIG. 10 is a graph showing the improvement in thermal efficiency and the reduction in operational troubles when powdered iron ore is separated and recovered. 10... Smelting furnace, 11... Iron bath, 12... Slag layer, 14... Raw material chute, 15... Gas conduit,
16... First separation device, 21... Oxygen lance, 2
2.23.24 nozzle, 25.26... tuyere, 27.
28... Pressurizing device, 30... Preheating preliminary reduction furnace, 35
...Second separation device, 40...Preheating device, 41...
- Switching valve, 42... Closing valve, 45... Third separation device.
Claims (1)
し、炭材、造滓剤とともに、製錬炉に装入し、先端がス
ラグ層の上面乃至下面のレベルにある上吹き酸素ランス
より脱炭用酸素および二次燃焼用酸素を吹き込むととも
に、底吹き羽口及び横吹き羽口から不活性ガス、ＣＯ、
またはプロセスガスを吹き込む溶融還元方法であって、 （１）前記横吹き羽口からのガス流の少なくとも一部が
前記底吹き羽口から吹きこまれたガスにより盛りあがっ
た溶湯部分に当たるようにして、（２）前記予熱予備還
元炉に導入される前記製錬炉の排ガス温度を３００℃乃
至１３００℃、（３）前記製錬炉で発生するガスの酸化
度 ［（Ｈ＿２Ｏ＋ＣＯ＿２）／（Ｈ＿２＋Ｈ＿２Ｏ＋ＣＯ
＋ＣＯ＿２）］を０．５乃至１．０（４）予熱予備還元
炉における予備還元率を３０％以下、とし、前記予熱予
備還元炉からキャリオーバーされた鉱石を排ガスと分離
して、前記予熱予備還元炉または前記製錬炉に装入する
ことを特徴とする溶融還元法。 ２）前記排ガスと分離された鉱石は高温のまま、単味ま
たは粉状の炭材と混合して前記羽口または前記上吹き酸
素ランスから製錬炉に吹き込むことを特徴とする特許請
求の範囲第１項に記載の溶融還元法。 ３）予熱予備還元された鉄鉱石を、粗粒単味または粗粒
と微粒と混合して高温のまま、前記製錬炉にその炉口か
ら重力落下により装入することを特徴とする特許請求の
範囲第１項または第２項に記載の溶融還元法。 ４）塊状または粗粒の炭材を単味または粉状の炭材と混
合して、前記製錬炉にその炉口から重力落下により装入
することを特徴とする特許請求の範囲第１項乃至第３項
のいずれか一に記載の溶融還元法。 ５）鉱石を流動層型の予熱予備還元炉で予熱、予備還元
して、炭材、造滓剤とともに、製錬炉に装入し、上吹き
酸素ランスから酸素を吹き込む溶融還元装置であつて、
前記上吹き酸素ランスは脱炭用酸素ノズル、２次燃焼用
酸素ノズルまたは粉体吹き込み用ノズルを有し、前記製
錬炉の炉底または側壁に設けられ、不活性ガス、ＣＯ、
またはプロセスガスを吹き込む羽口と、前記製錬炉の排
ガスから粉体を分離する第１の分離装置と、前記予熱予
備還元炉の排ガスから粉体を分離する第２の分離装置と
、前記第２の分離装置の排ガスにより原料供給装置から
導入される鉱石を予熱する予熱装置と、前記予熱装置の
排ガスから微粉の鉱石を分離する第３の分離装置と、を
具備することを特徴とする溶融還元装置。[Claims] 1) The ore is preheated and prereduced in a fluidized bed type preheating prereduction furnace, and then charged into a smelting furnace together with carbonaceous material and slag forming agent, so that the tip of the ore is on the upper or lower surface of the slag layer. Oxygen for decarburization and oxygen for secondary combustion are blown in from the top-blown oxygen lance at the level, and inert gas, CO,
or a melting reduction method in which a process gas is blown, wherein: (1) at least a part of the gas flow from the side blowing tuyere hits a molten metal portion that has risen due to the gas blown from the bottom blowing tuyere; (2) The temperature of the exhaust gas from the smelting furnace introduced into the preheating pre-reduction furnace is 300°C to 1300°C. (3) The oxidation degree of the gas generated in the smelting furnace [(H_2O+CO_2)/(H_2+H_2O+CO
+CO_2)] from 0.5 to 1.0 (4) The preliminary reduction rate in the preheating preliminary reduction furnace is set to 30% or less, and the ore carried over from the preheating preliminary reduction furnace is separated from the exhaust gas to A smelting reduction method characterized by charging the reduction furnace or the smelting furnace. 2) The ore separated from the exhaust gas is mixed with plain or powdered carbonaceous material while remaining at a high temperature, and is blown into the smelting furnace through the tuyere or the top-blown oxygen lance. The melting reduction method described in item 1. 3) A patent claim characterized in that iron ore that has been preheated and pre-reduced is charged into the smelting furnace by falling by gravity from the furnace mouth while the iron ore is mixed with coarse grains or coarse grains and fine grains and is kept at a high temperature. The smelting reduction method according to item 1 or 2. 4) The method of claim 1 is characterized in that lumpy or coarse-grained carbonaceous materials are mixed with single or powdered carbonaceous materials and charged into the smelting furnace by falling by gravity from the furnace mouth. The melting reduction method according to any one of items 3 to 3. 5) A smelting-reduction device in which ore is preheated and pre-reduced in a fluidized bed type preheating pre-reduction furnace, charged into a smelting furnace together with carbon material and slag-forming agent, and oxygen is blown in from a top-blowing oxygen lance. ,
The top-blowing oxygen lance has an oxygen nozzle for decarburization, an oxygen nozzle for secondary combustion, or a nozzle for blowing powder, is provided at the bottom or side wall of the smelting furnace, and is provided with an inert gas, CO,
Alternatively, a tuyere for blowing process gas into, a first separation device for separating powder from the exhaust gas of the smelting furnace, a second separation device for separating the powder from the exhaust gas of the preheating pre-reduction furnace, and a second separation device for separating the powder from the exhaust gas of the preheating pre-reduction furnace; A melting method characterized by comprising: a preheating device that preheats the ore introduced from the raw material supply device using the exhaust gas of the second separation device; and a third separation device that separates fine ore from the exhaust gas of the preheating device. reduction device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2858188A JPH01205014A (en) | 1988-02-09 | 1988-02-09 | Smelting reduction method and apparatus thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2858188A JPH01205014A (en) | 1988-02-09 | 1988-02-09 | Smelting reduction method and apparatus thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01205014A true JPH01205014A (en) | 1989-08-17 |
Family
ID=12252566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2858188A Pending JPH01205014A (en) | 1988-02-09 | 1988-02-09 | Smelting reduction method and apparatus thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01205014A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012513007A (en) * | 2008-12-22 | 2012-06-07 | 莱蕪鋼鉄集団有限公司 | Smelting furnace, steel making facility, and steel making method |
-
1988
- 1988-02-09 JP JP2858188A patent/JPH01205014A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012513007A (en) * | 2008-12-22 | 2012-06-07 | 莱蕪鋼鉄集団有限公司 | Smelting furnace, steel making facility, and steel making method |
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