JPH06271919A - Method for pre-treating coal and ore for smelting reduction furnace - Google Patents
Method for pre-treating coal and ore for smelting reduction furnaceInfo
- Publication number
- JPH06271919A JPH06271919A JP6223093A JP6223093A JPH06271919A JP H06271919 A JPH06271919 A JP H06271919A JP 6223093 A JP6223093 A JP 6223093A JP 6223093 A JP6223093 A JP 6223093A JP H06271919 A JPH06271919 A JP H06271919A
- Authority
- JP
- Japan
- Prior art keywords
- coal
- ore
- furnace
- heating
- temperature
- 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- Withdrawn
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、鉄鉱石と石炭から鉄を
製造する溶融還元法において、石炭原単位を低下するた
めの石炭と鉱石の前処理方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretreatment method for coal and ore for reducing the coal consumption rate in a smelting reduction method for producing iron from iron ore and coal.
【０００２】[0002]
【従来の技術】現在、鉄鉱石からの製鉄は、コークスを
還元材として用いる高炉法による大量生産と、水素ある
いは炭化水素ガスを還元材とする直接還元法による比較
的小規模の生産が行われている。一方、高炉にとって代
わり得る新しい製鉄技術として溶融還元法が研究されて
いる。溶融還元法は大規模の製鉄を、高炉法のようにコ
ークス炉、焼結設備などを含む膨大な設備を必要とせ
ず、また、原料炭と呼ばれるコークス用の特殊な石炭に
依存せずに、フレキシブルに製造することを目標として
いるが、最近、地球環境の点からＣＯ2 発生量を減少す
ることが重要な要求項目になっている。2. Description of the Related Art At present, iron ore is produced in large quantities by a blast furnace method using coke as a reducing material and on a relatively small scale by a direct reduction method using hydrogen or hydrocarbon gas as a reducing material. ing. On the other hand, the smelting reduction method is being researched as a new iron-making technology that can replace the blast furnace. The smelting reduction method does not require huge equipment such as coke oven and sintering equipment for large-scale iron making like the blast furnace method, and does not depend on special coal for coke called coking coal, Although the goal is to manufacture it flexibly, recently it has become an important requirement to reduce the amount of CO 2 generated from the viewpoint of the global environment.
【０００３】ＣＯ2 発生量を減少するには、鉄鉱石の還
元材として水素あるいは炭化水素ガスを用いて水素によ
る還元の比率を高めることが考えられるが、現時点では
そのような還元材は一般炭に比べて高価である。すなわ
ち、高炉に代わり得る量産新製鉄法としては、一般炭を
用いて、いかにして石炭原単位を低下するかが重要な課
題と言える。In order to reduce the amount of CO 2 generated, it is conceivable to use hydrogen or a hydrocarbon gas as a reducing agent for iron ore to increase the rate of reduction with hydrogen. At present, such a reducing agent is steam coal. It is more expensive than. In other words, as a mass production new iron-making method that can replace the blast furnace, it can be said that how to use steam coal to reduce the coal consumption rate is an important issue.
【０００４】溶融還元法にはいくつかのタイプがある
が、石炭原単位低減を狙える可能性のあるものの１つ
に、溶融還元炉で雰囲気２次燃焼率； {(%CO2 ）＋(%Ｈ2 Ｏ)}/{(%CO）＋(%CO2 ）＋(%Ｈ2 ）
＋(%Ｈ2 Ｏ)}×100(%) を高めることに着眼した方式がある。この方式ではガス
を上底吹きできる転炉状の容器に、多量のスラグを共存
させ、底吹きガスによって撹拌されるメタルと上吹き酸
素ジェットを遮断することによって、２次燃焼率のアッ
プと、鉄系ダストの発生抑制を可能にしている。Although there are several types of smelting reduction methods, one of those that may be aimed at reducing the coal intensity is one of the secondary combustion rates in the atmosphere in the smelting reduction furnace; {(% CO 2 ) + (% H 2 O)} / {( % CO) + (% CO 2) + (% H 2)
There is a method focused on increasing + (% H 2 O)} × 100 (%). In this system, a large amount of slag is made to coexist in a converter-like vessel that can blow gas from the top and bottom, and the metal and the top-blown oxygen jet that are agitated by the bottom-blown gas are shut off to increase the secondary combustion rate, This makes it possible to suppress the generation of iron-based dust.
【０００５】この方式での石炭原単位の最小となる操業
条件は、図１に示すように、物質、熱バランスで決まる
線Ａと、固定炭素バランスで決まる線Ｂの交点として決
まることが分かった。用いる石炭の中の揮発分含有量が
低いと、交点の２次燃焼率の値は高くなり、その２次燃
焼率までは２次燃焼率が高くなるほど石炭原単位は低く
できる。It has been found that the minimum operating condition of the coal basic unit in this system is determined by the intersection of the line A determined by the substance and heat balance and the line B determined by the fixed carbon balance as shown in FIG. . When the volatile content in the coal used is low, the value of the secondary combustion rate at the intersection becomes high, and the higher the secondary combustion rate is, the lower the basic unit of coal can be made.
【０００６】一方、石炭の揮発分含有量が高くなると、
交点の２次燃焼率が低くなり、その交点の２次燃焼率が
それ以上に高くなるとかえって石炭原単位は高くなる。
溶融還元炉で２次燃焼率を制御することは可能であるか
ら、石炭原単位を下げるには、線Ａと線Ｂの交点の石炭
原単位の値を低くすることが必要である。図１は、鉱石
はＦｅＯに予備還元され、石炭は揮発分３０％の場合を
示す。On the other hand, when the volatile content of coal increases,
When the secondary combustion rate at the intersection becomes low and the secondary combustion rate at the intersection becomes higher than that, the coal consumption rate becomes high.
Since it is possible to control the secondary combustion rate in the smelting reduction furnace, it is necessary to lower the value of the coal basic unit at the intersection of the line A and the line B in order to lower the coal basic unit. FIG. 1 shows the case where the ore was pre-reduced to FeO and the coal had a volatile content of 30%.
【０００７】この交点の石炭原単位を下げるには、次の
ような方策がある。炉内に持ち込まれる水分を極力、
少なくすること。炉内に持ち込まれた水分は、炭材の固
定炭素と反応してＣ＋Ｈ2 Ｏ＝ＣＯ＋Ｈ2 、固定炭素を
消耗し、図１の線Ｂを押し上げるので好ましくない。
石炭に含まれる揮発分が低いこと。石炭の揮発分含有量
が高いと同じく図１の線Ｂを押し上げる。鉱石、鉱石
などの原料が予熱されていること。予熱温度が高いほ
ど、図１の線Ｂが押し下げられる。鉱石の予備還元率
ができるだけ高いこと。The following measures can be taken to reduce the unit coal consumption at this intersection. Moisture brought into the furnace as much as possible,
To reduce. The water brought into the furnace is not preferable because it reacts with the fixed carbon of the carbonaceous material to consume C + H 2 O = CO + H 2 , the fixed carbon and push up the line B in FIG. 1.
Low volatile matter contained in coal. When the volatile content of coal is high, the line B in FIG. 1 is pushed up. Raw materials such as ores and ores have been preheated. The higher the preheat temperature, the more the line B in FIG. 1 is pushed down. The pre-reduction rate of ore is as high as possible.
【０００８】予備還元率が高いほど、図１の線の線Ａお
よびＢは押し下げられる。これをいかにして実施するか
であるが、従来技術によれば、鉱石の乾燥、予熱・予備
還元と、石炭の乾燥、予熱あるいは石炭乾留が別々に行
われて、処理されたものが溶融還元炉に送り込まれる。
その場合には予備処理に数多くの設備を要して、溶融還
元が高炉法にとって代わろうとする目的に反する。The higher the pre-reduction rate, the more the lines A and B of the line in FIG. 1 are pushed down. According to the prior art, how to do this is that ore drying, preheating / pre-reduction, and coal drying, preheating or coal carbonization are performed separately, and the processed one is melt-reduced. It is sent to the furnace.
In that case, a large amount of equipment is required for pretreatment, which defeats the purpose of smelting reduction replacing the blast furnace method.
【０００９】また、鉱石予備還元のための還元ガスをど
のように得るかが問題である。鉱石予備還元のために、
系外から還元材を得ようとすればその費用および総合石
炭原単位の低減の目的に反し、一方、系内から得られる
ものとして、溶融還元炉の排ガスを利用しようとすれ
ば、２次燃焼率を上げることと、予備還元率を上げるこ
とは矛盾関係にあるため、総合的な石炭原単位低減は制
約される。Another problem is how to obtain a reducing gas for ore preliminary reduction. For ore pre-reduction,
If the reducing agent is obtained from outside the system, it is against the purpose of reducing the cost and the total coal unit consumption. On the other hand, if the exhaust gas from the smelting reduction furnace is used as the one obtained from inside the system, the secondary combustion is generated. There is a contradiction between increasing the rate and increasing the pre-reduction rate, which limits the overall reduction of coal intensity.
【００１０】これらの問題を解決するために考えられた
方法がＬＷ法である。これは、図２，図３に示すよう
に、石炭と鉱石を溶融還元炉からの排ガスで間接加熱し
て、石炭の乾留とそれによって発生したガスによって鉱
石を還元して、溶融還元炉に装入する。小規模実験が行
われて、その結果に基づく試算では石炭原単位を４００
kg/t台まで下げられると報告されている。この方法では
石炭と鉱石が同時に常温から加熱されて、発生したガス
は高温側に流れ、高温に加熱された鉱石と接触して鉱石
の還元が進行する。これを可能にしているのが、間接加
熱であるが、この間接加熱がこの方法をスケールアップ
しようとする時に伝熱速度の点で最大の問題になる。ス
ケールアップしようとすると、加熱しようとする原料単
位重量あたりの伝熱量が小さくなるためである。A method considered to solve these problems is the LW method. As shown in Fig. 2 and Fig. 3, the coal and the ore are indirectly heated by the exhaust gas from the smelting reduction furnace, the ore is reduced by the carbonization of the coal and the gas generated by the carbonization, and the coal is loaded into the smelting reduction furnace. To enter. A small-scale experiment was conducted, and the calculation based on the results showed a coal intensity of 400
It is reported that it can be lowered to the kg / t range. In this method, the coal and the ore are simultaneously heated from room temperature, the generated gas flows to the high temperature side, comes into contact with the ore heated to the high temperature, and the reduction of the ore proceeds. This is possible with indirect heating, which is the biggest problem in terms of heat transfer rate when trying to scale up the process. This is because the amount of heat transfer per unit weight of the raw material to be heated becomes smaller when scale-up is attempted.
【００１１】この処理をロータリーキルンのような比較
的大型の加熱法で実施しようとすれば、もし、通常のキ
ルン操業のように原料を同時に加熱すれば、石炭からの
揮発分が発生する温度では、鉱石は還元速度が小さいの
で、揮発分は鉱石予備還元に有効に利用できない。キル
ンの中で途中から石炭を加える方法があるが、通常の方
法では鉱石の予備還元促進に十分な効果が得られていな
い。If this treatment is carried out by a relatively large heating method such as a rotary kiln, if the raw materials are heated at the same time as in a normal kiln operation, at a temperature at which volatile matter is generated from coal, Ore has a low reduction rate, so volatiles cannot be effectively used for ore pre-reduction. There is a method of adding coal from the middle of the kiln, but the usual method is not sufficiently effective in promoting the preliminary reduction of ore.
【００１２】また、溶融還元工程の前処理という観点か
らは、石炭は、溶融還元炉の中で４mm以上程度でなけれ
ば、炉内上昇ガスによって飛散し、溶融還元炉の安定操
業のために必要な固定炭素量を確保するためには、石炭
原単位がそれだけ高くなってしまうという問題がある。Further, from the viewpoint of pretreatment of the smelting reduction process, coal is scattered by ascending gas in the smelting reduction furnace unless it is about 4 mm or more in the smelting reduction furnace and is necessary for stable operation of the smelting reduction furnace. In order to secure a fixed amount of fixed carbon, there is a problem that the unit consumption of coal becomes higher.
【００１３】チャーの粒度を確保しつつ、乾留時に発生
するガスで効果率に鉱石の予備還元を行うという方法は
従来技術のなかに見いだせなかった。A method of preliminarily reducing ores with a gas generated during carbonization while maintaining the grain size of char has not been found in the prior art.
【００１４】[0014]
【発明が解決しようとする課題】このような事情に鑑
み、本発明は、石炭原単位を下げるための溶融還元の前
処理法としては、石炭の乾燥、予熱、乾留、鉱石の乾
燥、予熱、乾留発生ガスによる予備還元を、できるだけ
数が少なく、かつ簡単な装置で行い、予備処理の中間製
品として、予備還元鉱石とともに、サイズが細かくなり
すぎていない乾留チャーを歩留り高く得るための方法を
提供しようとするものである。In view of the above circumstances, the present invention provides, as a pretreatment method for smelting reduction for lowering the unit consumption of coal, drying of coal, preheating, carbonization, drying of ore, preheating, Preliminary reduction by dry distillation generated gas is carried out with a simple device with the fewest possible number, and as an intermediate product of the pretreatment, a method for obtaining high yield of dry distillation char that does not become too fine with prereduced ore is provided. Is what you are trying to do.
【００１５】[0015]
【課題を解決するための手段】本発明の要旨は次の通り
である。The gist of the present invention is as follows.
【００１６】（１）粒径１mm以下の粉鉱石を５００℃以
上、９００℃以下に予熱する第１工程、および予熱され
た粉鉱石に、粒径５mm以上の粒子が８０wt％以上含まれ
ている石炭を加えて最高９００℃までの温度範囲に加熱
する第２工程からなることを特徴とする溶融還元炉用の
石炭、鉱石の前処理方法。(1) The first step of preheating powdered ore having a particle diameter of 1 mm or less to 500 ° C. or more and 900 ° C. or less, and the preheated powdered ore contains 80 wt% or more of particles having a particle diameter of 5 mm or more. A pretreatment method for coal and ore for a smelting reduction furnace, which comprises a second step of adding coal and heating it in a temperature range up to 900 ° C.
【００１７】（２）第１工程を、粉鉱石を上から下の方
向に動かしながらの加熱と、同じく粉鉱石を横方向に動
かしながらの加熱を組み合わせて行うことを特徴とする
（１）記載の溶融還元炉用の石炭、鉱石の前処理方法。(2) The first step is carried out by combining heating while moving the powder ore from the top to the bottom and heating while moving the powder ore in the horizontal direction in the same manner (1). For pretreatment of coal and ore for smelting reduction furnaces in Japan.
【００１８】（３）第２工程を、石炭と予熱された粉鉱
石を横方向に移動させながら行うことを特徴とする
（１）記載の溶融還元炉用の石炭、鉱石の前処理方法。(3) The method for pretreatment of coal and ore for a smelting reduction furnace according to (1), wherein the second step is carried out while laterally moving the coal and the preheated powdered ore.
【００１９】（４）石炭と予熱された粉鉱石を同時に上
下方向に動かすことなく加熱することを特徴とする
（３）記載の方法。(4) The method according to (3), characterized in that the coal and the preheated powdered ore are simultaneously heated without moving vertically.
【００２０】（５）石炭と予熱された粉鉱石を炉の回転
運動によって撹拌しながら加熱することを特徴とする
（３）記載の方法。(5) The method according to (3), wherein the coal and the preheated powdered ore are heated while being stirred by the rotary motion of the furnace.
【００２１】（６）第２工程の加熱を軸方向に突起物を
設けた炉で行うことを特徴とする（５）記載の方法。(6) The method according to (5), characterized in that the heating in the second step is performed in a furnace provided with projections in the axial direction.
【００２２】（７）石灰石を添加して加熱することを特
徴とする（１）記載の方法。(7) The method according to (1), characterized in that limestone is added and heated.
【００２３】（８）添加する石炭を炉外で粒度別に３種
類以上に分け、粒径が大きいものの方が長時間粉鉱石と
接するように添加位置を設定して加熱することを特徴と
する（５）記載の方法。(8) Characteristically, the coal to be added is divided into three or more types according to the particle size outside the furnace, and the addition position is set so that the one with the larger particle size is in contact with the powdered ore for a longer time (heating is carried out ( 5) The method described.
【００２４】（９）第２工程の加熱炉の原料排出側の空
気過剰率を１．０５以下に保つことを特徴とする（１）
記載の方法。(9) It is characterized in that the excess air ratio on the raw material discharge side of the heating furnace of the second step is maintained at 1.05 or less.
The method described.
【００２５】（１０）第２工程において、石炭から生成
したチャーが、平均として１．５wt％以上の揮発分を含
有した状態で処理を終わることを特徴とする（１）記載
の方法。(10) The method according to (1), wherein in the second step, the char produced from coal ends the treatment in a state where the char contains an average of 1.5 wt% or more volatile matter.
【００２６】（１１）第１工程の加熱に用いたガスで空
気を予熱して、その予熱空気でもって第２工程の燃焼加
熱を行い、加熱最高温度部の温度とＣＯ／ＣＯ2 比の間
に次の関係が成り立つように温度調整することを特徴と
する（１）記載の方法。(11) Air is preheated with the gas used for the heating in the first step, and the combustion heating in the second step is performed with the preheated air so that the temperature between the heating maximum temperature portion and the CO / CO 2 ratio is between The method according to (1), characterized in that the temperature is adjusted so that the following relationship holds.
【００２７】 温度（℃）≧８９０＋２５（％ＣＯ2 ／％ＣＯ） （１２）得られた予備還元粉鉱石、石炭加熱による生成
チャー、あるいは、石灰石の混合物を、底吹きガスによ
って撹拌され酸素を上吹きされている溶融還元中の炉
に、そのスラグの上面より上方１．５ｍ以下の位置から
該炉内に装入することを特徴とする（１）または（７）
記載の方法。Temperature (° C.) ≧ 890 + 25 (% CO 2 /% CO) (12) The resulting pre-reduced powdered ore, char produced by heating coal, or a mixture of limestone is agitated by a bottom-blown gas to raise oxygen. It is characterized in that the furnace during the smelting reduction being blown is charged into the furnace from a position not more than 1.5 m above the upper surface of the slag (1) or (7).
The method described.
【００２８】[0028]
【作用】以下、本発明の実施方法を詳細に説明する。The operation of the present invention will be described in detail below.
【００２９】本発明を実施するのに用いられる装置の例
を図２および図３に示す。図２は縦型の鉱石予熱炉とロ
ータリーキルンのような横型回転炉を組み合わしたもの
で、図３においては縦型の鉱石予熱炉とグレートキルン
のような非回転の炉を組み合わせたもので、いずれも原
料はまず上から下の方向に動かしながら加熱され、つい
で横方向に動かしながら加熱されることが共通してい
る。これらの装置全体を通して、粉鉱石を５００℃以
上、９００℃以下に予熱する第１工程、予熱された鉱石
に、５mm以上が８０wt％以上の石炭を加えて最高９００
℃まで加熱する第２工程からなる処理が行われる。An example of a device used to practice the present invention is shown in FIGS. Fig. 2 shows a combination of a vertical ore preheating furnace and a horizontal rotating furnace such as a rotary kiln, and Fig. 3 shows a combination of a vertical ore preheating furnace and a non-rotating furnace such as a great kiln. It is common for raw materials to be heated while moving from top to bottom, and then to move laterally. Throughout these devices, the first step of preheating powdered ore to 500 ° C or higher and 900 ° C or lower, adding preheated ore with coal of 5% or more and 80 wt% or more to a maximum of 900
A treatment consisting of a second step of heating to ° C is performed.
【００３０】図２においては、第２工程が石炭と粉鉱石
を横方向に移動させながら行われるが、その場合、石炭
と粉鉱石を炉の回転運動によって撹拌しながら加熱する
ことに特徴がある。一方、図３においても、第２工程が
石炭と粉鉱石を横方向に移動させながら行われるが、そ
の場合に石炭と粉鉱石を上下方向には動かさないで加熱
することに特徴がある。いずれも適正な条件で操業すれ
ば本発明の目的とする処理を効率的に実施することがで
きる。まず、図２の装置を用いる場合について操業方法
の詳細を述べる。In FIG. 2, the second step is carried out while moving the coal and the fine ore laterally. In this case, the coal and the fine ore are heated while being stirred by the rotary motion of the furnace. . On the other hand, also in FIG. 3, the second step is performed while moving the coal and the fine ore laterally, but in that case, the feature is that the coal and the fine ore are heated without moving vertically. In either case, if the operation is carried out under appropriate conditions, the treatment intended by the present invention can be carried out efficiently. First, the operation method will be described in detail for the case of using the apparatus of FIG.
【００３１】本発明の処理の対象とする鉄鉱石は１mm以
下の粉鉱石である。このような粉鉱石は存在量が多く安
価に入手できるばかりでなく、本発明においては、石炭
から生成するチャーの粒を大きく保つために必要であ
る。なぜならば、塊鉱石を用いると、鉱石が加熱・還元
の過程で割れて、鋭いエッジをもったものになる。これ
を炭材と一緒に長時間加熱すると、チャーが摩耗によっ
て粉化しやすいという問題があるからである。一般に粉
鉱石をロータリーキルンで加熱すると、リングを形成し
やすいことが問題とされているが本発明では、鉱石の加
熱温度をリングが形成しない９００℃以下にしているの
でその問題は回避できる。The iron ore targeted for the treatment of the present invention is a powdered ore of 1 mm or less. Not only is such powdered ore available in large amounts at low cost, but it is necessary in the present invention to keep the size of char grains produced from coal large. This is because, if a lump ore is used, the ore will crack during the heating / reduction process and will have a sharp edge. This is because if this is heated for a long time together with the carbonaceous material, the char tends to be pulverized due to abrasion. Generally, when powdered ore is heated in a rotary kiln, it is problematic that a ring is easily formed, but in the present invention, the heating temperature of the ore is set to 900 ° C. or lower at which the ring is not formed, so that problem can be avoided.
【００３２】粉鉱石を５００℃以上、９００℃以下に予
熱してから石炭を加える理由は次の通りである。鉱石の
温度が５００℃未満の温度で石炭を加えると、石炭から
発生した水素を含む還元性ガスと接しても鉱石が十分に
反応できないので鉱石還元に有効に利用できないので好
ましくない。一方、鉱石温度が９００℃超で石炭を加え
ると、石炭の加熱速度が大きくなりすぎて、石炭の割れ
が進み、本発明が目的の１つにしている乾留チャーの粒
度を大きく保つことに反するので好ましくない。The reason why coal is added after preheating the fine ore to 500 ° C. or higher and 900 ° C. or lower is as follows. If coal is added at a temperature of the ore lower than 500 ° C., the ore cannot sufficiently react even if it comes in contact with a reducing gas containing hydrogen generated from the coal, and therefore it is not preferable for the ore reduction. On the other hand, when coal is added at an ore temperature of over 900 ° C., the heating rate of the coal becomes too high and cracking of the coal progresses, which is contrary to keeping the particle size of the carbonization char, which is one of the purposes of the present invention, large. It is not preferable.
【００３３】このような温度まで鉱石を予熱するには、
例えば図２の装置のように、粉鉱石を上から下の方向に
動かしながら行う加熱と、鉱石を横方向に動かしながら
行う加熱の組み合わせによって行う。すなわち、粉鉱石
を、まず、邪魔板などを途中に設けて滞留時間を確保で
きるようにした炉に上から粉鉱石を供給して、第２炉か
ら供給される高温排ガスで加熱する。予熱された鉱石を
ロータリーキルンのような回転炉に入れて、後述の第２
工程として石炭を加える場所まで更に加熱を続ける。こ
の場合の加熱源は第２工程から供給される排ガスに空気
を吹き込んで更に燃焼を進めたものである。このように
加熱装置を２つに分けることによって、熱効率を高める
ことと、加熱後の鉱石温度を所定の条件に合わせること
を、最もコンパクトな装置で行うことができる。To preheat the ore to such a temperature,
For example, as in the apparatus shown in FIG. 2, heating is performed while moving the fine ore from the top to the bottom and heating performed while moving the ore laterally. That is, the powdered ore is first supplied from above to a furnace in which a baffle plate or the like is provided in the middle so that a residence time can be secured, and is heated by the high-temperature exhaust gas supplied from the second furnace. Put the preheated ore into a rotary kiln such as a rotary kiln, and
Continue heating to the point where coal is added as a process. In this case, the heating source is one that blows air into the exhaust gas supplied from the second step to further promote combustion. By thus dividing the heating device into two, it is possible to increase the thermal efficiency and adjust the ore temperature after heating to a predetermined condition with the most compact device.
【００３４】第２工程では、該温度に予熱された鉱石
に、粒径５mm以上の粒子が８０wt％以上含まれている石
炭を加えて最高９００℃までの温度範囲に加熱して行わ
れる。この工程の目的の１つは、後続の溶融還元炉にお
いてスラグフォーミング抑制などに有効に効率よく用い
られるチャーを得ることである。したがって、粒度が小
さすぎる石炭を用いると本工程で生成チャーの粒径は小
さくなって、溶融還元炉に装入すると上昇ガス流によっ
てキャリーオーバーされる確率が高い。溶融還元炉でキ
ャリーオーバーされるものを、本発明によって前処理し
ても、本発明が目的とする全体としての石炭原単位低減
には結び付けることができない。The second step is carried out by adding coal containing 80 wt% or more of particles having a diameter of 5 mm or more to the ore preheated to the temperature and heating it to a temperature range of up to 900 ° C. One of the purposes of this step is to obtain a char that is effectively and efficiently used for suppressing slag foaming in the subsequent smelting reduction furnace. Therefore, if coal having too small a particle size is used, the particle size of the char produced in this step becomes small, and when charged into the smelting reduction furnace, there is a high probability of carryover due to the rising gas flow. Even if the carry-over in the smelting reduction furnace is pretreated by the present invention, it cannot be linked to the reduction of the total coal unit consumption which is the objective of the present invention.
【００３５】ただし、粒径の小さい石炭も本発明の処理
で、鉱石の予備還元率を高めること、また、生成した塊
状のチャーの表面酸化を抑制する間接効果があるので、
本発明で用いる石炭については粒径が５mm以上が８０wt
％以上であることを必要条件とする。石炭の添加は、ロ
ータリーキルンでは途中投炭装置を用いると炉回転を続
けながら行うことができる。このように、粒度、密度が
異なる２つの原料を加熱するために第２工程では第２工
程を、石炭と粉鉱石を横方向に移動させながら行うこと
が必要である。However, coal having a small particle size also has the indirect effect of increasing the pre-reduction rate of the ore and suppressing the surface oxidation of the generated massive char by the treatment of the present invention.
Regarding the coal used in the present invention, the particle size of 5 mm or more is 80 wt.
It is a necessary condition to be at least%. Coal can be added in the rotary kiln while continuing the rotation of the furnace by using a coal throwing device. As described above, in order to heat the two raw materials having different particle sizes and densities, it is necessary to perform the second step in the second step while moving the coal and the fine ore laterally.
【００３６】第２工程では加熱温度を上げるほど粉鉱石
の予備還元率は上げることができるが、温度が９００℃
超では、固定炭素による還元が起こり始める。固定炭素
の還元では、この工程よりも後続の溶融還元炉の方が効
率的に行うことができるので、全体としての石炭原単位
を低くするには第２工程の最高加熱温度は９００℃でな
ければならない。この条件は雰囲気による固定炭素の酸
化消耗防止、および粉鉱石によるリング生成防止も同時
に満足させている。In the second step, the higher the heating temperature, the higher the pre-reduction rate of the powdered ore, but the temperature is 900 ° C.
Above, reduction by fixed carbon begins to occur. Since fixed carbon can be reduced more efficiently in the subsequent smelting reduction furnace than in this step, the maximum heating temperature in the second step must be 900 ° C in order to lower the overall coal consumption. I have to. This condition simultaneously satisfies the prevention of oxidation and consumption of fixed carbon by the atmosphere and the prevention of ring formation by fine ore.
【００３７】第２工程をロータリーキルンのような回転
炉で、石炭と粉鉱石を炉の回転運動によって撹拌しなが
ら加熱すると、熱供給の点では有利であり、また、生産
速度あたりの必要容積を他の方法よりも小さくできる。
しかし、ロータリーキルンで粒径、比重の異なる混合物
を加熱すると、粒子の分布が形成され、粒径が大きく比
重の小さい炭材が上の方に集まりやすい。炭材から発生
する還元性ガスを還元能が高い状態で鉱石と接触させる
のは、逆に、鉱石層の下に炭材が巻き込まれることが望
ましい。それを可能にする方法が、第２工程の加熱を軸
方向に突起物をつけた炉で行うことである。それによっ
て、炉回転に伴いころがりやすい炭材粒は移動が抑えら
れ、その上に粉鉱石が積み重なり、還元ガスの利用効率
が高められる状態が得られる。It is advantageous in terms of heat supply to heat the second step in a rotary kiln such as a rotary kiln while agitating coal and fine ore by the rotary motion of the kiln, and the required volume per production rate is different. Can be smaller than the above method.
However, when a mixture having different particle diameters and specific gravities is heated in the rotary kiln, a distribution of particles is formed, and carbonaceous materials having large particle diameters and small specific gravity tend to gather in the upper part. In order to bring the reducing gas generated from the carbonaceous material into contact with the ore with a high reducing ability, conversely, it is desirable that the carbonaceous material be caught under the ore layer. A method that makes this possible is to carry out the heating in the second step in a furnace having axial projections. As a result, the movement of the carbonaceous material particles, which are likely to roll with the rotation of the furnace, is suppressed, and the fine ore is piled up on the carbon material particles, so that the utilization efficiency of the reducing gas is improved.
【００３８】本発明においては、石炭の乾留と、その時
に発生するガスによる鉱石の予備還元をマッチングさせ
ることが必要である。予備還元を進めるには、還元反応
熱の供給が必要であるから、第２工程を連続的に行う炉
としては長さに下限がある。一方、石炭の乾留の時間は
サイズ、温度によって決まるので、とくに、本発明を大
型化する場合には、石炭を一度に加えてしまうと乾留が
先行して起こり、それを十分に鉱石予備還元に利用でき
ない場合がある。そのための方策は、添加する石炭を炉
外で粒度別に３種類以上に分け、粒径が大きいものの方
が長時間粉鉱石と接しているように添加位置を設定する
ことである。In the present invention, it is necessary to match the dry distillation of coal with the preliminary reduction of ore by the gas generated at that time. Since it is necessary to supply the heat of reduction reaction in order to proceed with the preliminary reduction, there is a lower limit to the length of the furnace for continuously performing the second step. On the other hand, since the time of carbonization of coal is determined by the size and temperature, especially when enlarging the present invention, if carbon is added all at once, carbonization will precede, and it will be sufficient for ore pre-reduction. May not be available. A measure for that is to divide the coal to be added into three or more types according to the particle size outside the furnace, and set the addition position so that the larger particle size is in contact with the fine ore for a long time.
【００３９】この方法によって、石炭からの還元性ガス
の発生が第２工程の全域を通して起こり、熱供給とマッ
チングさせることが可能になる。石炭の粒径が大きいも
のの方が長時間粉鉱石と接しているように添加位置を設
定した理由は、粒径が大きいものほど、揮発分の発生時
間が長いこと、比表面積が小さいので、長時間加熱雰囲
気にさらされても、酸化や摩耗によって消耗する比率が
小さくできるからである。なお、装入位置の数は、２箇
所では効果が小さいので３箇所以上にすることが必要で
ある。By this method, the generation of reducing gas from coal occurs throughout the entire second step and can be matched with the heat supply. The reason for setting the addition position so that the coal with a larger particle size is in contact with the powdered ore for a longer time is that the larger the particle size, the longer the volatile component generation time and the smaller the specific surface area. This is because the rate of consumption due to oxidation and wear can be reduced even when exposed to a heating atmosphere for a long time. It should be noted that the number of charging positions should be three or more because the effect is small at two positions.
【００４０】以上のような方策を講じても、第２工程の
加熱炉の原料排出側から空気が多量に侵入すれば、予備
還元された鉱石の再酸化、およびチャーの固定炭素分の
燃焼が起こりやすくなる。これを抑制するための条件を
実験的に検討したところ、空気過剰率を１．０５以下に
なるように、空気の侵入の抑制およびバーナーへの供給
空気を調整することが必要であることが分かった。ただ
し、空気過剰率は、第２工程の加熱に供給される、塊状
石炭以外の燃料を完全燃焼するに必要な空気中の酸素に
対する実際の供給空気（バーナーに供給されるものおよ
び、炉端から侵入する空気の和）中の酸素の比によって
定義される。Even if the above measures are taken, if a large amount of air enters from the raw material discharge side of the heating furnace of the second step, reoxidation of the pre-reduced ore and combustion of fixed carbon content of char will occur. It is easy to happen. When the conditions for suppressing this were experimentally examined, it was found that it was necessary to suppress the intrusion of air and adjust the air supplied to the burner so that the excess air ratio was 1.05 or less. It was However, the excess air ratio refers to the actual supply air (oxygen supplied to the burner and intrusion from the furnace end) with respect to oxygen in the air required for complete combustion of fuel other than the agglomerated coal, which is supplied for heating in the second step. Defined as the ratio of oxygen in the air).
【００４１】石炭はできるだけ揮発分が除去されている
ことが望ましい一方、揮発分が除去されて還元性ガス発
生が少なくなった状態で混合物の加熱を続けると、雰囲
気によって、予備還元された鉱石の再酸化、およびチャ
ーの固定炭素分の燃焼が起こりやすくなって、溶融還元
法全体を通しての石炭原単位を低下するという本発明の
目的に反する。While it is desirable that the volatile components of the coal be removed as much as possible, if the mixture is continuously heated while the volatile components are removed and the reducing gas generation is reduced, the atmosphere reduces the pre-reduced ore. Reoxidation and burning of fixed carbon in char tend to occur, which goes against the object of the present invention to reduce the coal consumption rate throughout the smelting reduction process.
【００４２】予備還元された鉱石の再酸化、チャーの固
定炭素分の燃焼を防止するための条件を実験的に検討し
た結果、第２工程終わりの生成チャーが、平均として
１．５wt％以上の揮発分を含有した状態で処理を終わる
ことが必要であることが分かった。したがって、第２工
程終わりの生成チャーが、平均として揮発分を１．５〜
５％の範囲になるように調整するのが、プロセス全体と
しての石炭原単位を低くするには最も有利である。As a result of experimentally examining the conditions for preventing reoxidation of the pre-reduced ore and combustion of fixed carbon content of char, the char produced at the end of the second step is 1.5 wt% or more on average. It has been found necessary to end the process with volatile content. Therefore, the char produced at the end of the second step has an average volatile content of 1.5 to
Adjusting to be in the range of 5% is the most advantageous for lowering the coal intensity of the entire process.
【００４３】本発明においては第２工程の加熱を雰囲気
の酸化度を上げないで必要な温度にできるようにするこ
とが必要条件である。そのためには、燃焼用の空気とし
て常温のものを用いることは有利ではない。幸い本発明
においては、第１工程で鉱石の予熱に用いたガスの顕熱
があまっているので、これを空気に熱交換すれば２００
℃以上の予熱空気を得ることができる。この予熱空気で
もって、第２工程の燃焼加熱を行い、加熱最高温度部の
温度とＣＯ／ＣＯ2 比の間に次の関係が成り立つように
調整すると、予備還元を進めることおよび、再酸化を防
止することの両方を満足させることができることが分か
り、全体の石炭原単位を下げる上で有利である。 温度（℃）≧８９０＋２５（％ＣＯ2 ／％ＣＯ）In the present invention, it is a necessary condition that the heating in the second step can be performed at a required temperature without increasing the degree of oxidation of the atmosphere. For that purpose, it is not advantageous to use the air at room temperature as the air for combustion. Fortunately, in the present invention, the sensible heat of the gas used for preheating the ore in the first step is sensible.
Preheated air above ℃ can be obtained. Combustion heating in the second step is performed with this preheated air, and if adjustment is made so that the following relationship holds between the temperature of the heating maximum temperature portion and the CO / CO 2 ratio, pre-reduction and reoxidation are performed. It has been found that both prevention can be satisfied, which is advantageous in reducing the overall coal intensity. Temperature (° C) ≧ 890 + 25 (% CO 2 /% CO)
【００４４】溶融還元炉では、粉鉱石および炭材の夾雑
物として持ち込まれるＳｉＯ2 を主成分とするものを滓
化して、操業に都合の良いＣａＯ／ＳｉＯ2 が１．１〜
１．４のスラグをするために、１５０kg/t−メタル以上
という多量の石灰源を装入する必要がある。通常は、石
灰源としては、石灰石を炉外で１１００℃以上に加熱し
て分解・生成させたＣａＯが溶融還元炉で加えられる
が、この場合にはその処理比が高く、溶融還元製鉄のコ
ストに及ぼす影響が無視できない。In the smelting reduction furnace, what is contained as a contaminant of powdered ores and carbonaceous materials and whose main component is SiO 2 is slagged, and CaO / SiO 2 which is convenient for operation is 1.1 to
In order to make 1.4 slag, it is necessary to charge a large amount of lime source of 150 kg / t-metal or more. Usually, as a lime source, CaO obtained by heating limestone outside the furnace to 1100 ° C. or higher to decompose and generate it is added in the smelting reduction furnace, but in this case, the treatment ratio is high and the cost of smelting reduction ironmaking is high. Can not be ignored.
【００４５】そこで、本発明においては、全体としての
コストダウンのために、上記前処理工程に石灰石が加え
られる。加えられた石灰石は予熱されるが、９００℃以
下の加熱であるために、熱分解はほとんど起こさない。
しかし、予熱に熱が利用できるので、本発明の炉内の熱
バランスの改善に役立つ。なお、９２０℃以上に加熱さ
れるとＣＯ2 が発生してこれが、予備還元された粉鉱石
の再酸化やチャーの酸化などの悪影響を及ぼすが、本発
明の条件ではそのような問題は起こらない。Therefore, in the present invention, limestone is added to the pretreatment step in order to reduce the cost as a whole. The added limestone is preheated, but since it is heated at 900 ° C or less, thermal decomposition hardly occurs.
However, since heat can be used for preheating, it is useful for improving the heat balance in the furnace of the present invention. It should be noted that when heated to 920 ° C. or higher, CO 2 is generated, which adversely affects reoxidation of the pre-reduced powder ore and oxidation of char, but such a problem does not occur under the conditions of the present invention. .
【００４６】予熱された石灰石は溶融還元炉のなかで熱
分解するが、この発生ガスは溶融還元炉の雰囲気ガス温
度を低減して耐火物の損耗を小さくする効果がある。本
発明の方法では石灰石の予熱はできるだけ低位のエネル
ギーで行われることが望ましく、初期から粉鉱石と一緒
に加熱されることが望ましい。The preheated limestone is thermally decomposed in the smelting reduction furnace, and this generated gas has the effect of reducing the temperature of the atmosphere gas in the smelting reduction furnace and reducing the wear of the refractory. In the method of the present invention, it is desirable that the limestone is preheated with energy as low as possible, and it is desirable that the limestone is heated together with the fine ore from the beginning.
【００４７】以上、本発明を図２の装置を用いて行う場
合について述べたが、次の図３の装置を用いて行う場合
について、異なる点だけを述べる。図３の装置を用いて
行う場合には、石炭と粉鉱石は上下方向に動かすことな
く加熱される。この場合には、石炭から発生する還元性
ガスと鉱石の接触効率を高めることができ、また、ごく
表面部を除いて、還元された鉱石の再酸化、生成した石
炭チャーの酸化を抑制できるという特徴がある。しか
し、熱供給速度が小さくなるので生産性を大きくしにく
い欠点はある。水平方向に移動する鉄製のパレットを容
器として用いる場合には、第１工程で予熱された鉱石
と、新たに加える石炭が装入され、平均温度が最高９０
０℃まで加熱された後、容器から排出される。その他の
条件は図２の装置を用いる場合とほぼ同じである。The case where the present invention is carried out by using the apparatus shown in FIG. 2 has been described above. However, only the points different from the case where the present invention is carried out by using the apparatus shown in FIG. 3 will be described. When the apparatus of FIG. 3 is used, coal and fine ore are heated without moving vertically. In this case, it is possible to increase the contact efficiency between the reducing gas generated from the coal and the ore, and also to suppress the reoxidation of the reduced ore and the oxidation of the generated coal char except for the very surface part. There are features. However, there is a drawback that it is difficult to increase the productivity because the heat supply rate becomes small. When an iron pallet that moves in the horizontal direction is used as a container, the ore preheated in the first step and newly added coal are charged, and the average temperature is up to 90%.
After being heated to 0 ° C., it is discharged from the container. Other conditions are almost the same as the case of using the apparatus of FIG.
【００４８】以上のような方法によって、粉鉱石の予
熱、予備還元物、石炭加熱によって生成した塊状チャー
の混合物、更には石灰石を加えた場合には加熱石灰石を
含む混合物が得られた。この混合物をどのように溶融還
元して鉄を製造するかについて種々の検討を行った結
果、以下に述べる方法が最も実用的であることが分かっ
た。By the method as described above, a mixture of powdered ore preheated, pre-reduced product, agglomerated char produced by heating coal, and a mixture containing heated limestone when limestone was added were obtained. As a result of various studies on how to melt-reduce this mixture to produce iron, the method described below was found to be most practical.
【００４９】すなわち溶融還元炉としては、底吹きガス
によって溶融物が撹拌され、酸素が上吹きされている炉
に、スラグを３５０kg/t−溶融メタル以上存在させた状
態でスラグの上方から装入する方法である。上から装入
する方法では粉鉱石が飛散することが懸念されたが、装
入する位置がスラグ面よりも上１．５ｍ以下であれば、
装入する原料の乱れが小さく、粉鉱石の飛散率は２wt％
以内に抑えられることが分かった。That is, as the smelting reduction furnace, the molten material is stirred by the bottom-blown gas, and the furnace in which oxygen is blown upward is charged from above the slag with 350 kg / t-molten metal or more being present. Is the way to do it. With the method of charging from above, it was feared that the powdered ore would be scattered, but if the charging position is 1.5 m or less above the slag surface,
Disturbance of raw materials to be charged is small, and powder ore scattering rate is 2 wt%
It turns out that it can be suppressed within.
【００５０】具体的には炉体の側壁に上記の条件を満足
する装入口を設け、予備処理された原料混合物を、少量
のガスで浮遊させながらあるいはスクリューフィーダー
で溶融還元炉のなかに装入する。この方法によれば、粉
や塊が混じった原料を分けることなく装入できるので熱
的にも有利である。Specifically, the side wall of the furnace body is provided with a charging port satisfying the above conditions, and the pretreated raw material mixture is charged into the smelting reduction furnace while suspending it with a small amount of gas or with a screw feeder. To do. According to this method, the raw material mixed with powder or lumps can be charged without being separated, which is also thermally advantageous.
【００５１】以上のような方法によって、本発明が目的
とする後続の溶融還元工程と併せて製鉄の石炭原単位を
下げるための前処理法として、石炭の乾燥、予熱、乾
留、鉱石の乾燥、予熱、乾留発生ガスによる予備還元
を、できるだけ数が少なく、かつ簡単な装置で行い、予
備処理の中間製品として、予備還元鉱石とともに、サイ
ズが細かくなりすぎていない乾留チャーを歩留り高く得
るということが実現される。By the above-mentioned method, as a pretreatment method for lowering the coal basic unit of ironmaking in combination with the subsequent smelting reduction step which is the object of the present invention, coal drying, preheating, carbonization, ore drying, Preheating and preliminary reduction by dry distillation generated gas are performed by a simple device with the fewest possible number, and it is possible to obtain high yield of dry distillation char that does not become too fine in size together with prereducing ore as an intermediate product of pretreatment. Will be realized.
【００５２】[0052]
〔実施例１〕図２の形式の装置を用いた。 （装置） 縦型の予熱炉；高さ１５ｍで内部に５０cmおきに棚が存
在し、上部から装入した原料が加熱されるにしたがって
順次下方に移動してゆく方式の炉。 横型回転炉；内径３．５ｍ、長さ３５ｍのロータリーキ
ルン。途中５ｍおきに石炭投入装置がつけられている。
内部の装入側から、１２ｍ，１８ｍ，２４ｍの位置に高
さ１５cm、回転軸方法に長さ１ｍの耐火物性の突起物が
つけられている。原料排出側には空気侵入防止のシール
装置がついている。原料排出側から、溶融還元炉の高温
排ガスと、予熱空気が加熱源として装入される。Example 1 An apparatus of the type shown in FIG. 2 was used. (Apparatus) Vertical preheating furnace; a furnace with a height of 15 m and a shelf every 50 cm inside, and moves downward as the raw materials charged from the top are heated. Horizontal rotary furnace; rotary kiln with inner diameter 3.5m and length 35m. A coal feeding device is attached every 5 m on the way.
From the inner charging side, 12 m, 18 m, and 24 m heights are provided with 15 cm in height, and the rotating shaft method is provided with refractory-like projections having a length of 1 m. The raw material discharge side is equipped with a sealing device to prevent air from entering. From the raw material discharge side, high temperature exhaust gas of the smelting reduction furnace and preheated air are charged as a heating source.
【００５３】（使用原料） 粉鉱石；成分Ｆｅ2 Ｏ3 ；９１．２％、ＳｉＯ2 ；４．
８％、Ａｌ2 Ｏ3 ；１．２％、水分；２．５％ 粒度構成；０．５mm以下；７５wt％、０．５〜１．０m
m；２５wt％ 石炭 ；成分；固定炭素分；５６％、揮発分；３２％、
灰分；１２％ 粒度構成；ふるい分によって次の４種類に分けた。(Raw materials used) Powder ore; Component Fe 2 O 3 ; 91.2%, SiO 2 ;
8%, Al 2 O 3 ; 1.2%, moisture; 2.5% Grain size composition; 0.5 mm or less; 75 wt%, 0.5 to 1.0 m
m; 25 wt% coal; component; fixed carbon content; 56%, volatile matter; 32%,
Ash content; 12% particle size composition;
【００５４】Ａ；２５mm以上、Ｂ；１５〜２５mm、Ｃ；
１０〜１５mm、Ｄ；５〜１０mm 石灰石；ＣａＣＯ3 ；９７wt％、水分；２％、サイズ；
５〜２５mmA: 25 mm or more, B: 15 to 25 mm, C;
10-15 mm, D; 5 to 10 mm limestone; CaCO 3; 97 wt% water; 2% size;
5-25 mm
【００５５】（操業）粉鉱石およびその重量の１０wt％
の石灰石を縦型予熱炉に装入して、横型回転炉の排ガス
（縦型炉への入り口においてＣＯ；０．５％、温度；６
３０℃）によって加熱して、平均５２０℃まで加熱す
る。いずれも水分はほとんどゼロになったが他の成分変
化は起こっていない。なお、縦型炉出口の排ガスはサイ
クロンで除塵後、温度３２０℃である。これで空気を２
１０℃まで加熱して、この空気は横型回転炉に供給し
た。排ガスはＣＯ；０．１％以下で、バグフィルターで
除塵して系外に排出した。(Operation) 10% by weight of powdered ore and its weight
Limestone is charged into a vertical preheating furnace, and exhaust gas from a horizontal rotary furnace (CO at the entrance to the vertical furnace; 0.5%, temperature; 6
30 ° C.) to an average of 520 ° C. In all cases, the water content was almost zero, but no changes in other components occurred. The exhaust gas at the outlet of the vertical furnace has a temperature of 320 ° C. after removing dust with a cyclone. This is the air 2
After heating to 10 ° C., this air was supplied to a horizontal rotary furnace. The exhaust gas was CO; 0.1% or less, and dust was removed by a bag filter and discharged to the outside of the system.
【００５６】横型回転炉は、傾き；３／１０００、回転
速度；１．５RPM で操業した。粉鉱石および石灰石の混
合物は横型回転炉に移され、原料装入端から１０ｍのと
ころまでは石炭を添加することなく加熱されて、平均温
度を８００℃まで上昇させた。装入端から９ｍの位置で
雰囲気に空気が吹き込まれ、ＣＯ；０．５％まで燃焼さ
せた。原料装入端から１０ｍ，１５ｍ，２０ｍ，２５ｍ
の位置から次のように石炭の装入を行った。１０ｍの位
置；上記Ａの石炭を粉鉱石の１２wt％、１５ｍの位置；
上記の石炭Ｂを鉱石の１１wt％、２０ｍの位置；上記の
石炭Ｃを鉱石の１０wt％、２５ｍの位置；上記の石炭Ｄ
を粉鉱石の７wt％。The horizontal rotary furnace was operated at a tilt of 3/1000 and a rotation speed of 1.5 RPM. The mixture of fine ore and limestone was transferred to a horizontal rotary furnace and heated up to 10 m from the raw material charging end without adding coal to raise the average temperature to 800 ° C. Air was blown into the atmosphere at a position 9 m from the charging end, and CO was burned to 0.5%. 10m, 15m, 20m, 25m from raw material charging end
Charging was carried out from the position as follows. Position of 10 m; coal of the above A is 12 wt% of powdered ore, position of 15 m;
Coal B above is 11 wt% of ore at 20 m position; Coal C above is 10 wt% of ore at 25 m position; Coal D above
7 wt% of powdered ore.
【００５７】原料の最高温度部の温度は８８５℃であ
り、リングの形成は見られなかった。横型回転炉に加熱
燃料として溶融還元炉の排ガス（ＣＯ；４１％、Ｃ
Ｏ2 ；３２％、Ｈ2 ；７％、温度９００℃）を供給し、
それを完全に燃焼するに必要な空気の９０〜１０３％の
空気が４割を炉端からの侵入物として、残りを予熱空気
として加えた。炉内最高温度部の温度は１０５０℃であ
り、その場所の雰囲気ＣＯ／ＣＯ2 は０．２であった。The temperature of the highest temperature part of the raw material was 885 ° C. and no ring formation was observed. Exhaust gas from a smelting reduction furnace (CO; 41%, C as heating fuel for a horizontal rotary furnace)
O 2 ; 32%, H 2 ; 7%, temperature 900 ° C.),
90% to 103% of the air necessary for completely burning it was added as 40% as an intruder from the furnace end and the rest as preheated air. The temperature of the highest temperature part in the furnace was 1050 ° C., and the atmosphere CO / CO 2 at that location was 0.2.
【００５８】（生成物）予備還元鉱石としては、鉄のう
ちの８５％がＦｅＯ、１５％がＦｅのものが得られた。
チャーは、平均して、残留揮発分が１．９％のものが、
固定炭素分として収率９３％で得られた。サイズは、５
mm以下が１３wt％、５〜１０mmが２５％、１０mm以上が
６２wt％であった。石灰石は、ＣａＣＯ3 が９６％のも
のが収率９８％で得られた。(Product) As the pre-reduced ore, iron having 85% of FeO and 15% of Fe was obtained.
Char has an average residual volatile content of 1.9%,
It was obtained as a fixed carbon content in a yield of 93%. The size is 5
mm or less was 13% by weight, 5 to 10 mm was 25%, and 10 mm or more was 62% by weight. Limestone having a CaCO 3 content of 96% was obtained with a yield of 98%.
【００５９】（溶融還元炉での使用）溶融還元炉は窒素
底吹き、酸素上吹きの転炉型の炉でスラグは側壁に設け
た孔から連続的に排滓される。それによって決まるスラ
グ面より１．４ｍの位置に設けた原料供給口より予備還
元鉱石、石炭チャー、石灰石の混合物をスクリューフィ
ーダー方式で装入した。(Use in Smelting Reduction Furnace) The smelting reduction furnace is a nitrogen bottom-blown and oxygen top-blown converter type furnace, and slag is continuously discharged from holes provided in the side wall. A mixture of pre-reduced ore, coal char, and limestone was charged by a screw feeder method from a raw material supply port provided at a position 1.4 m from the slag surface determined by the above.
【００６０】また、上記の石炭Ｄを装入鉱石の３〜５wt
％、排ガス組成を見ながら装入した。溶融スラグは常に
３５０kg/t−溶融メタル以上、存在している状態で酸素
ガス供給し、酸素供給量と上記の追加石炭によって、溶
融メタルの温度を１３９０〜１４５０℃の範囲になるよ
うに、また、排ガス中のＣＯ；３７〜４２％、ＣＯ2；
３０〜３５％、になるように調整した。系全体として、
石炭原単位６７０kgで、溶銑（Ｃ；３．９％）を製造で
きた。 〔実施例２〕図３の形式の装置を用いた。 （装置） 縦型の予熱炉；実施例１と同じである。 横型加熱炉 ；幅１．８ｍ、長さ１．５ｍの鉄製パレッ
トが水平方向に移動する。炉の長さは４０ｍである。加
熱は炉の上面からバーナーによって行われる。パレット
の移動速度は６０ｍ／ｈである。Further, the above coal D was charged in an amount of 3 to 5 wt% of the charged ore.
%, While charging the exhaust gas composition. The molten slag is always supplied with oxygen gas in a state of 350 kg / t-molten metal or more, and the temperature of the molten metal is kept in the range of 1390 to 1450 ° C. depending on the oxygen supply amount and the additional coal. , CO in the exhaust gas; 37~42%, CO 2;
It was adjusted to be 30 to 35%. As a whole system,
Hot metal (C; 3.9%) could be produced with 670 kg of coal unit. Example 2 An apparatus of the type shown in FIG. 3 was used. (Apparatus) Vertical preheating furnace; the same as in Example 1. Horizontal heating furnace: An iron pallet with a width of 1.8 m and a length of 1.5 m moves horizontally. The length of the furnace is 40 m. Heating is done by a burner from the top of the furnace. The moving speed of the pallet is 60 m / h.
【００６１】（使用原料）鉱石は実施例１と同じであ
る。石炭は組成は実施例１と同じであるが、粒度構成
は、２７mm以上；２２wt％、１５〜２５mm；２５wt％、
１０〜１５mm；２２wt％、５〜１０mm；２０wt％、５mm
以下；６wt％である。(Material used) The ore is the same as in Example 1. The composition of coal is the same as in Example 1, but the grain size composition is 27 mm or more; 22 wt%, 15-25 mm; 25 wt%,
10-15mm; 22wt%, 5-10mm; 20wt%, 5mm
Below; 6 wt%.
【００６２】（操業）予熱のための縦型炉については、
石灰石を加えなかったこと以外は実施例１と同じであ
る。予熱された鉱石に、石炭を鉱石１ｔに対しての４０
０kgの割合で配合したものを鉄製パレットに入れ、最高
温度８９０℃まで加熱した。(Operation) Regarding the vertical furnace for preheating,
Same as Example 1 except that no limestone was added. Preheated ore, coal to 40 tons of ore
The mixture of 0 kg was put in an iron pallet and heated to a maximum temperature of 890 ° C.
【００６３】（生成物）予備還元鉱石は平均として、鉄
のうちの７９％がＦｅＯ、２１％がＦｅのものが得られ
た。チャーは、平均して、残留揮発分が１．７％のもの
が、固定炭素分として収率９８％で得られた。サイズ
は、５mm以下が１０wt％、５mm〜１０mmが２５％、１０
mm以上が７５wt％であった。(Product) As the average of the pre-reduced ores, 79% FeO and 21% Fe were obtained. Char having an average residual volatile content of 1.7% was obtained as a fixed carbon content in a yield of 98%. The size is 10 wt% for 5 mm or less, 25% for 5 mm to 10 mm, 10
mm or more was 75 wt%.
【００６４】（溶融還元炉での使用）実施例１と同じ方
法で使用し、系全体として、石炭原単位６５０kgで、溶
銑（Ｃ；３．９％）を製造できた。(Use in Smelting Reduction Furnace) Using the same method as in Example 1, hot metal (C: 3.9%) could be produced with 650 kg of coal unit as the whole system.
【００６５】[0065]
【発明の効果】本発明によって、現行高炉法に対する溶
融還元法の種々の特徴をいかしつつ、製鉄時の石炭原単
位の低減を通してＣＯ2 発生量を低減することが可能に
なり、経済的および環境面から効果が大きい。EFFECTS OF THE INVENTION The present invention makes it possible to reduce the amount of CO 2 generated by reducing the coal consumption rate during ironmaking while making full use of the various features of the smelting reduction method with respect to the current blast furnace method. The effect is great from the aspect.
【図１】溶融還元炉における石炭原単位の決定機構の図
表を示す。FIG. 1 is a diagram showing a determination mechanism of a coal basic unit in a smelting reduction furnace.
【図２】本発明を実施するのに用いる装置の説明図を示
す。FIG. 2 shows an illustration of an apparatus used to carry out the present invention.
【図３】本発明を実施するのに用いる他の装置の説明図
を示す。FIG. 3 shows an illustration of another device used to practice the invention.
１：縦型予熱炉 １１：スラグ ２：粉鉱石、石灰石 １２：メタル ３：排ガス １３：石炭 ４：熱交換器 １４：予熱原料 ５：高温ガス １６：横型回転炉 ６：横型回転炉 ７：溶融還元炉 １０：排ガス 1: Vertical preheating furnace 11: Slag 2: Powder ore, limestone 12: Metal 3: Exhaust gas 13: Coal 4: Heat exchanger 14: Preheating raw material 5: High temperature gas 16: Horizontal rotary furnace 6: Horizontal rotary furnace 7: Melt Reduction furnace 10: Exhaust gas
Claims (12)
９００℃以下に予熱する第１工程、および予熱された粉
鉱石に、粒径５mm以上の粒子が８０wt％以上含まれてい
る石炭を加えて最高９００℃までの温度範囲に加熱する
第２工程からなることを特徴とする溶融還元炉用の石
炭、鉱石の前処理方法。1. A powdered ore having a particle size of 1 mm or less is heated to 500 ° C. or more,
From the first step of preheating to 900 ℃ or less, and the second step of adding coal containing 80 wt% or more of particles with a particle size of 5 mm or more to preheated powdered ore and heating it to a temperature range of up to 900 ℃ A method for pretreatment of coal and ore for a smelting reduction furnace, which comprises:
動かしながらの加熱と、同じく粉鉱石を横方向に動かし
ながらの加熱を組み合わせて行うことを特徴とする請求
項１記載の方法。2. The first step is carried out by combining heating while moving the powder ore from the top to the bottom and heating while moving the powder ore in the horizontal direction in the same manner. Method.
横方向に移動させながら行うことを特徴とする請求項１
記載の方法。3. The second step is performed while laterally moving the coal and the preheated powdered ore.
The method described.
向に動かすことなく加熱することを特徴とする請求項３
記載の方法。4. The coal and the preheated powdered ore are simultaneously heated without moving in the vertical direction.
The method described.
によって撹拌しながら加熱することを特徴とする請求項
３記載の方法。5. A process according to claim 3, characterized in that the coal and the preheated powdered ore are heated with stirring by the rotary movement of a furnace.
た炉で行うことを特徴とする請求項５記載の方法。6. The method according to claim 5, wherein the heating in the second step is carried out in a furnace provided with protrusions in the axial direction.
する請求項１記載の方法。7. The method according to claim 1, wherein limestone is added and heated.
上に分け、粒径が大きいものの方が長時間粉鉱石と接す
るように添加位置を設定して加熱することを特徴とする
請求項５記載の方法。8. The coal to be added is divided into three or more types according to the particle size outside the furnace, and the one with the larger particle size is heated by setting the addition position so as to contact the powdered ore for a longer time. The method according to 5.
剰率を１．０５以下に保つことを特徴とする請求項１記
載の方法。9. The method according to claim 1, wherein the excess air ratio on the material discharge side of the heating furnace in the second step is maintained at 1.05 or less.
チャーが、平均として１．５wt％以上の揮発分を含有し
た状態で処理を終わることを特徴とする請求項１記載の
方法。10. The method according to claim 1, wherein, in the second step, the treatment is finished in a state where the char produced from coal contains volatile matter of 1.5 wt% or more on average.
予熱して、その予熱空気でもって第２工程の燃焼加熱を
行い、加熱最高温度部の温度とＣＯ／ＣＯ2比の間に次
の関係が成り立つように温度調整することを特徴とする
請求項１記載の方法。 温度（℃）≧８９０＋２５（％ＣＯ2 ／％ＣＯ）11. Air is preheated with the gas used for heating in the first step, and combustion heating in the second step is carried out with the preheated air, and the temperature between the temperature of the maximum heating temperature portion and the CO / CO 2 ratio is increased. The method according to claim 1, wherein the temperature is adjusted so that the following relationship holds. Temperature (° C) ≧ 890 + 25 (% CO 2 /% CO)
よる生成チャー、あるいは、石灰石の混合物を、底吹き
ガスによって撹拌され酸素を上吹きされている溶融還元
中の炉に、そのスラグの上面より上方１．５ｍ以下の位
置から該炉内に装入することを特徴とする請求項１また
は７記載の方法。12. The slag upper surface of the obtained pre-reduced powdered ore, char produced by heating coal, or a mixture of limestone is put into a furnace during smelting reduction that is agitated by a bottom-blown gas and is overblown with oxygen. 8. The method according to claim 1, wherein the furnace is charged from a position higher than 1.5 m or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6223093A JPH06271919A (en) | 1993-03-22 | 1993-03-22 | Method for pre-treating coal and ore for smelting reduction furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6223093A JPH06271919A (en) | 1993-03-22 | 1993-03-22 | Method for pre-treating coal and ore for smelting reduction furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06271919A true JPH06271919A (en) | 1994-09-27 |
Family
ID=13194154
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6223093A Withdrawn JPH06271919A (en) | 1993-03-22 | 1993-03-22 | Method for pre-treating coal and ore for smelting reduction furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06271919A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999034022A1 (en) * | 1997-12-26 | 1999-07-08 | Nkk Corporation | Refining method of molten iron and reduction smelting method for producing the molten iron |
| CN1059240C (en) * | 1995-11-03 | 2000-12-06 | 技术资源有限公司 | Duplex procedure for prodn. of metals and metal alloys from oxidic metal ores |
| JP2001131620A (en) * | 1999-11-02 | 2001-05-15 | Astec Irie Co Ltd | Smelting reduction method of iron oxide |
| US6273934B1 (en) | 1996-10-07 | 2001-08-14 | Technological Resouces Pty. Ltd. | Method and an apparatus for producing metals and metal alloys |
| JP2014141719A (en) * | 2013-01-25 | 2014-08-07 | Hyuga Seirensho:Kk | Operation method of rotary kiln |
| CN108359763A (en) * | 2018-02-23 | 2018-08-03 | 攀枝花正德环保新材料科技开发有限公司 | Vanadium titano-magnetite process equipment and processing technology |
| CN112508365A (en) * | 2020-11-26 | 2021-03-16 | 贵州电网有限责任公司 | Online coal consumption curve rolling correction method and system |
| CN114250333A (en) * | 2021-12-24 | 2022-03-29 | 徐卫兵 | Iron and steel smelting device |
-
1993
- 1993-03-22 JP JP6223093A patent/JPH06271919A/en not_active Withdrawn
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1059240C (en) * | 1995-11-03 | 2000-12-06 | 技术资源有限公司 | Duplex procedure for prodn. of metals and metal alloys from oxidic metal ores |
| US6174346B1 (en) | 1995-11-03 | 2001-01-16 | Technological Resource Pty. Ltd. | Duplex procedure for the production of metals and metal alloys from oxidic metal ores |
| US6273934B1 (en) | 1996-10-07 | 2001-08-14 | Technological Resouces Pty. Ltd. | Method and an apparatus for producing metals and metal alloys |
| US6837916B2 (en) | 1997-12-26 | 2005-01-04 | Nkk Corporation | Smelting reduction method |
| WO1999034022A1 (en) * | 1997-12-26 | 1999-07-08 | Nkk Corporation | Refining method of molten iron and reduction smelting method for producing the molten iron |
| KR100370920B1 (en) * | 1997-12-26 | 2003-02-05 | 닛폰 고칸 가부시키가이샤 | Refining method of molten iron and reduction smelting method for producing the molten iron |
| JP2001131620A (en) * | 1999-11-02 | 2001-05-15 | Astec Irie Co Ltd | Smelting reduction method of iron oxide |
| JP4581136B2 (en) * | 1999-11-02 | 2010-11-17 | 株式会社アステック入江 | Method for smelting reduction of iron oxide |
| JP2014141719A (en) * | 2013-01-25 | 2014-08-07 | Hyuga Seirensho:Kk | Operation method of rotary kiln |
| CN108359763A (en) * | 2018-02-23 | 2018-08-03 | 攀枝花正德环保新材料科技开发有限公司 | Vanadium titano-magnetite process equipment and processing technology |
| CN112508365A (en) * | 2020-11-26 | 2021-03-16 | 贵州电网有限责任公司 | Online coal consumption curve rolling correction method and system |
| CN112508365B (en) * | 2020-11-26 | 2022-07-01 | 贵州电网有限责任公司 | Online coal consumption curve rolling correction method and system |
| CN114250333A (en) * | 2021-12-24 | 2022-03-29 | 徐卫兵 | Iron and steel smelting device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR0131266B1 (en) | Process for the production of iron using converter | |
| EP0446860B1 (en) | A process for producing metals and metal alloys in a smelt reduction vessel | |
| US4045214A (en) | Method for producing steel | |
| JPH0360883B2 (en) | ||
| JP2001500243A (en) | Plants and processes for the production of metal melts | |
| CA1244656A (en) | Processes and appparatus for the smelting reduction of smeltable materials | |
| CA2408720C (en) | Method and device for producing pig iron or liquid steel pre-products from charge materials containing iron ore | |
| WO2003062474A1 (en) | Process for producing molten iron | |
| WO2002008471A1 (en) | A direct smelting process and apparatus | |
| US4756748A (en) | Processes for the smelting reduction of smeltable materials | |
| RU2669653C2 (en) | Method of producing granular metallic iron | |
| JPH06271919A (en) | Method for pre-treating coal and ore for smelting reduction furnace | |
| JP2004509231A (en) | Direct smelting method and equipment | |
| JP2002517607A (en) | Sustained iron production and solid waste minimization by enhanced direct reduction of iron oxide | |
| JP2002509194A (en) | Sustainable steelmaking process by effective direct reduction of iron oxide and solid waste | |
| AU713666B2 (en) | Process for producing liquid pig iron or intermediate steel products and installation for implementing it | |
| KR100236192B1 (en) | Process and method for producing hot metal as produce from fine iron ore | |
| JP2004176170A (en) | Method for producing molten iron | |
| JP2000045012A (en) | Method for utilizing dust in converter steel making | |
| JP4005683B2 (en) | Vertical furnace operation method for treating powdered waste | |
| JPH10168508A (en) | Production of molten iron | |
| JPS6232243B2 (en) | ||
| CN115948630A (en) | Smelting reduction furnace of hydrogen-rich high-oxygen high-air-temperature iron-making fluidized bed | |
| JPH07207313A (en) | Method for melting tin-plated steel sheet scrap | |
| JPH0483815A (en) | Melting-reduction iron manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000530 |