JPH11106815A - Operation of moving type hearth furnace - Google Patents
Operation of moving type hearth furnaceInfo
- Publication number
- JPH11106815A JPH11106815A JP26541097A JP26541097A JPH11106815A JP H11106815 A JPH11106815 A JP H11106815A JP 26541097 A JP26541097 A JP 26541097A JP 26541097 A JP26541097 A JP 26541097A JP H11106815 A JPH11106815 A JP H11106815A
- Authority
- JP
- Japan
- Prior art keywords
- hearth
- reducing material
- iron
- solid reducing
- fine
- 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.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/10—Making spongy iron or liquid steel, by direct processes in hearth-type furnaces
- C21B13/105—Rotary hearth-type furnaces
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は移動型炉床炉によ
る鉄鉱石から還元鉄を製造する技術に関する。The present invention relates to a technique for producing reduced iron from iron ore by a moving hearth furnace.
【０００２】[0002]
【従来の技術】粗鋼の生産は大きく高炉−転炉法、電気
炉法に分けられる。このうち、電気炉法はスクラップや
還元鉄を鉄原料として、それらを電気エネルギーで加熱
溶解させ、場合によっては精練し、鋼にしている。現状
ではスクラップを主な原料としているが、近年、スクラ
ップの需給の逼迫、電気炉法での高級製品の製造の流れ
から還元鉄の使用が増加しつつある。還元鉄を製造する
プロセスのひとつとして、特開昭63-108188 号公報に開
示されているように、水平方向に回転する炉床に鉄鉱石
と固体還元材とからなる層を積み付け、上部より輻射伝
熱によって加熱、鉄鉱石を還元し、還元鉄を製造する方
法がある。このような方法はこの方法を実施するための
設備の建設費が比較的安価であること、操業トラブルが
比較的少なくてすむこと等の優位な点がある。2. Description of the Related Art Crude steel production can be broadly divided into a blast furnace-converter method and an electric furnace method. Of these, the electric furnace method uses scrap or reduced iron as an iron raw material, heats and melts them with electric energy, and in some cases, refines it into steel. At present, scrap is the main raw material, but in recent years, the use of reduced iron has been increasing due to the tight supply and demand of scrap and the flow of manufacturing high-end products by the electric furnace method. As one of the processes for producing reduced iron, as disclosed in JP-A-63-108188, a layer made of iron ore and a solid reducing material is stacked on a horizontally rotating hearth, There is a method of producing reduced iron by heating and reducing iron ore by radiant heat transfer. Such a method has advantages in that the construction cost of equipment for implementing the method is relatively inexpensive, the operation trouble is relatively small, and the like.
【０００３】鉄鉱石はその産地によって差はあるが脈石
成分を含んでいる。また、固体還元材の代表例である石
炭、石炭チャー、コークスには灰分がある。還元操作の
みを基本的に行う特開昭63-108188 号公報のような方法
にあてはめると、製品の還元鉄に脈石が混入することは
間違いないとともに、還元材からの灰分も製品に付着し
混入する可能性がある。[0003] Iron ore contains a gangue component, although it varies depending on the place of production. In addition, coal, coal char, and coke, which are typical examples of solid reducing materials, have ash. When applied to a method such as JP-A-63-108188 in which only the reduction operation is basically performed, it is certain that gangue is mixed in the reduced iron of the product, and the ash from the reducing material adheres to the product. There is a possibility of contamination.
【０００４】電気炉では脱燐および脱硫を行うために石
灰を使用するが、脈石、灰分を含んだ還元鉄を電気炉に
投入すると塩基度調整のための石灰使用量が多くなり、
石灰のコストとともに石灰投入による電力使用量の増加
が余儀なくされる。In an electric furnace, lime is used for performing dephosphorization and desulfurization. However, when reduced iron containing gangue and ash is put into an electric furnace, the amount of lime used for adjusting basicity increases.
Along with the cost of lime, the increase in power consumption due to lime input is inevitable.
【０００５】ここで、通常の鉄鉱石と固体還元材とから
なる層を水平に移動する炉床に積み付け、炉の上方より
輻射伝熱によって鉄鉱石の還元を行う方法の概要につい
て説明する。多くの場合、水平に移動する炉床とは図１
のような回転炉床の形態を取っている。図１は回転炉床
炉の説明図である。この移動（回転）炉床６の上に鉄鉱
石と固体還元材からなる層11を積み付ける。移動（回
転）炉床６は耐火物が張られた炉体９によって覆われて
おり、また、場合によっては特開昭63-108188 号公報の
ようにさらに粒状耐火材で覆われている。炉上部にはバ
ーナー10が設置されていてそれを熱源として、移動（回
転）炉床上の鉄鉱石を還元する。なお、図１において、
７は排出装置、８は装入装置である。炉内温度は1300℃
前後にされているのが通常である。また、還元操作終了
後は炉外での酸化防止、ハンドリングを容易にするため
に移動（回転）炉床上で冷却器によって還元鉄を冷却し
たのち、回収するのが普通である。[0005] Here, an outline of a method of stacking a normal layer of iron ore and a solid reducing material on a horizontally moving hearth and reducing the iron ore by radiant heat transfer from above the furnace will be described. In most cases, a horizontally moving hearth is
It takes the form of a rotary hearth. FIG. 1 is an explanatory view of a rotary hearth furnace. A layer 11 made of iron ore and a solid reducing material is stacked on the moving (rotating) hearth 6. The moving (rotating) hearth 6 is covered with a furnace body 9 covered with a refractory, and in some cases, further covered with a granular refractory material as disclosed in JP-A-63-108188. A burner 10 is installed in the upper part of the furnace and uses the burner 10 as a heat source to reduce iron ore on a moving (rotating) hearth. In FIG. 1,
7 is a discharge device, and 8 is a charging device. Furnace temperature is 1300 ℃
It is usual that it is before and after. In addition, after the reduction operation is completed, the reduced iron is usually cooled by a cooler on a moving (rotating) hearth in order to prevent oxidation outside the furnace and to facilitate handling.
【０００６】鉱石の還元を行わせるためにはかなりの高
温にする必要があることから、その高温に耐えるため移
動炉床の上面は耐火物が張られ、また、場合によっては
特開昭63-108188 号公報のようにさらに粒状耐火材で覆
われている。当然のことながら炉の安定操業を確保し、
製品の製造コストを高くしないためにもこの耐火物は長
期に渡り損傷しないようにしなければならない。[0006] In order to reduce the ore, it is necessary to raise the temperature considerably. Therefore, the upper surface of the moving hearth is covered with a refractory to withstand the high temperature. It is further covered with a granular refractory material as in JP 108188. Naturally, we ensured stable operation of the furnace,
The refractory must be protected from long-term damage in order not to increase the production costs of the product.
【０００７】一方、脈石、灰分の混入がない還元鉄を得
る方法のひとつとして還元鉄を溶融させることが考えら
れる。溶融させると脈石、灰分はスラグとなり溶融鉄と
の比重差によって分離される。On the other hand, as one of methods for obtaining reduced iron free of gangue and ash, melting reduced iron is considered. When melted, gangue and ash become slag and are separated by the specific gravity difference from the molten iron.
【０００８】図２に示す移動炉床上に鉄鉱石と固体還元
材との混合粉を直接積み付けた場合の説明図のように、
移動炉床３の上に鉄鉱石と固体還元材との混合粉１を層
状に直接積み付け、溶融まで行わせる場合、およびさら
に炉床が粒状耐火材で覆われている場合を考える。上面
からの加熱により鉄鉱石の還元を行わせると、鉄鉱石は
脈石を含んだ還元鉄に、固体還元材からは灰分が残ると
ともに鉄鉱石と固体還元材との配合比によっては若干の
カーボン分も残った状態になる。ここで、さらに温度を
上昇させ還元鉄を溶融させると還元鉄は溶融鉄４に、脈
石、灰分はスラグ５になるがこの溶融過程で溶融鉄やス
ラグが直接移動炉床に接することになる。その際、溶融
鉄４、スラグ５が移動炉床３上の耐火物および粒状耐火
材を侵食する。粒状耐火材で覆われている場合は比重の
大きい溶融鉄が粒状耐火材の下に潜り込み移動炉床３上
の耐火物を侵食する。また、移動炉床３上で溶融鉄、ス
ラグを冷却器で冷却すると溶融鉄、スラグが移動炉床上
の耐火物に接着した状態になり、炉外への排出が困難に
なる。溶融によって脈石、灰分を除去することを炉外で
行わせることも当然考えられるが、それは新たなキュポ
ラのような設備を必要とすることは言うまでもない。As shown in FIG. 2, a mixed powder of iron ore and a solid reducing material is directly stacked on a moving hearth as shown in FIG.
It is assumed that the mixed powder 1 of iron ore and the solid reducing material is directly stacked on the moving hearth 3 in a layered manner and is melted, and that the hearth is further covered with a granular refractory material. When the iron ore is reduced by heating from the upper surface, the iron ore is reduced to reduced iron containing gangue, ash remains from the solid reducing agent, and some carbon is reduced depending on the mixing ratio of iron ore and solid reducing agent. Minutes remain. Here, when the temperature is further raised to reduce the reduced iron, the reduced iron becomes molten iron 4 and the gangue and ash become slag 5, but in this melting process, the molten iron and slag come into direct contact with the moving hearth. . At that time, the molten iron 4 and the slag 5 erode the refractory and the granular refractory on the moving hearth 3. When covered with the granular refractory material, the molten iron having a large specific gravity enters under the granular refractory material and erodes the refractory on the movable hearth 3. When the molten iron and slag are cooled by the cooler on the moving hearth 3, the molten iron and slag adhere to the refractory on the moving hearth, and it is difficult to discharge the molten iron and slag to the outside of the furnace. It is of course conceivable to remove gangue and ash by melting outside the furnace, but it goes without saying that this requires equipment such as a new cupola.
【０００９】[0009]
【発明が解決しようとする課題】この発明はこれらの問
題を解決するものであって、粉鉄鉱石と粉固体還元材と
を主とする原料を水平に移動する炉床に積み付け、炉床
上部より輻射伝熱によって鉄鉱石の還元を行う方法にお
いて、脈石、灰分の混入がない還元鉄を得て、電気炉で
の処理コストを低減させること、これを達成する上で水
平に移動する炉床が損傷しないこと、円滑な操業の維持
を同時に確保することともに、新たな脈石、灰分分離専
用の設備投資も必要としないことを実現する移動型炉床
炉の操業方法を提案することを目的とする。SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and a raw material mainly composed of fine iron ore and fine solid reducing material is stacked on a horizontally moving hearth, In the method of reducing iron ore by radiant heat transfer from the part, obtain reduced iron without gangue and ash contamination, reduce the processing cost in the electric furnace, move horizontally to achieve this To propose a method of operating a movable hearth furnace that ensures that the hearth is not damaged and that smooth operation is maintained at the same time, and that capital investment dedicated to new gangue and ash separation is not required. With the goal.
【００１０】[0010]
【課題を解決するための手段】この発明の要旨とすると
ころは以下の通りである。 粉鉄鉱石と粉固体還元材とを主とする原料を、水平に
移動する炉床上に層状に積み付け、炉内上方からの輻射
伝熱によって鉄鉱石の還元を行う移動型炉床炉の操業方
法において、粉鉄鉱石と粉固体還元材との混合粉または
粉鉄鉱石および粉副原料と粉固体還元材との混合粉を該
炉床上に、粉固体還元材を介して炉床に直接接触しない
ようにして小区画化して点在させ、還元された還元鉄を
該炉床上で少なくとも一度は溶融させることを特徴とす
る移動型炉床炉の操業方法（第１発明）。 粉固体還元材が、石炭チャー、コークス、一般炭また
は無煙炭のうちから選ばれる１種または２種以上の混合
粉である第１発明に記載の移動型炉床炉の操業方法（第
２発明）。The gist of the present invention is as follows. Operation of a moving hearth furnace in which raw materials mainly composed of fine iron ore and fine solid reducing material are stacked in layers on a horizontally moving hearth, and iron ore is reduced by radiant heat transfer from above the furnace. In the method, a mixed powder of fine iron ore and fine solid reducing material or a mixed powder of fine iron ore and fine powder raw material and fine solid reducing material is directly contacted with the hearth via the fine solid reducing material on the hearth. A method for operating a movable hearth furnace, wherein the reduced reduced iron is melted at least once on the hearth in such a manner that the reduced iron is divided and scattered so as not to be divided (first invention). The method for operating a movable hearth furnace according to the first invention (second invention), wherein the powdered solid reducing material is one or more mixed powders selected from coal char, coke, steam coal and anthracite. .
【００１１】[0011]
【発明の実施の形態】この発明の骨子とするところは移
動炉床上で還元鉄を溶融し、脈石、灰分をスラグにして
分離することにある。まず、移動炉床上に粉固体還元材
の単体の層を存在させる。粉固体還元材の単体の層は還
元材といいながら鉄鉱石を混合していないために基本的
に還元材としては作用せず、操業中には揮発分以外、あ
まり減少しない。固体還元材に占める灰分は10％程度で
しかなく、粉固体還元材の単体の層をマクロ的に見ると
1000℃以上の高温で固体状態を維持する、すなわち溶融
しない。よって粉固体還元材の単体の層自体が移動炉床
の上面の耐火物に溶着することはない。そこでこの層を
炉床の耐火物を保護する層として利用する。BEST MODE FOR CARRYING OUT THE INVENTION The gist of the present invention is that molten iron is melted on a moving hearth and gangue and ash are separated into slag and separated. First, a single layer of the powdered solid reducing material is present on the moving hearth. Although the single layer of the solid reductant powder is called a reductant and does not contain iron ore, it does not basically act as a reductant, and does not decrease much except volatile components during operation. The ash content in the solid reductant is only about 10%, and macroscopic view of the single layer of the powdered solid reductant
Maintains a solid state at high temperature of 1000 ° C or higher, that is, does not melt. Therefore, the single layer of the powdered solid reducing material does not adhere to the refractory on the upper surface of the moving hearth. Therefore, this layer is used as a layer for protecting the refractory of the hearth.
【００１２】すなわち、この発明は、小区画化した粉鉄
鉱石と粉固体還元材との混合粉または粉鉄鉱石および粉
副原料と粉固体還元材との混合粉を該粉固体還元材の単
体の層の中に点在させ、かつ、水平に移動する炉床には
直接には接しない状態で積み付け、還元を行ったのち還
元鉄を溶融する。一例として、図３(a), (b)および(c)
にこの発明に適合する炉床上への原料積み付け状態と還
元鉄を溶融したときの変化の説明図を示す。図３におい
て、１は粉鉄鉱石と粉固体還元材（または粉鉄鉱石およ
び粉副原料と粉固体還元材）との混合粉、２は粉固体還
元材の層、３は移動炉床、４は脈石、灰分が分離された
還元鉄および５はスラグである。この図３(a), (b)のよ
うに原料を積み付け、その上方より輻射伝熱によって加
熱すると粉鉄鉱石は混合された粉固体還元材の作用によ
り還元され、脈石を含んだ還元鉄になる。また、還元材
として用いられた粉固体還元材からは灰分が残る。副原
料は還元鉄、灰分を溶融させる際に溶融を容易にならし
めるために加えられるものであって、石灰石、蛍石、蛇
紋岩、ドロマイトなどである。これらは溶融する前まで
に結晶水の蒸発、一部の分解反応（例えば石灰石の主成
分であるCaCO3 はCaO に加熱分解されている）を起こし
ているものの固体を維持している。さらに加熱するとこ
れらは溶融を開始し、溶融鉄とスラグに分離する。この
とき、粉鉄鉱石と粉固体還元材との混合粉または粉鉄鉱
石、粉固体還元材、粉副原料との混合粉は粉固体還元材
の単体の層の中に点在し、かつ、水平に移動する炉床に
は直接には接しない形態で存在させていたため、溶融
鉄、溶融スラグは点在させていた小区画単位ごとに凝集
し、かつ、粉固体還元材の単体の層の上に塊状の還元鉄
が形成される。通常、溶融鉄、溶融スラグの比重は粉固
体還元材単体の層よりも大きいため、溶融鉄、溶融スラ
グが粉固体還元材単体の層の下に潜り込むことが考えら
れるが、粉鉄鉱石と粉固体還元材との混合粉（または粉
鉄鉱石および粉副原料と粉固体還元材との混合粉）を粉
固体還元材の単体の層の中で点在させていたため、溶融
鉄、溶融スラグはひとつひとつが小さなものであり、表
面張力の作用によって、粉固体還元材の単体の層の上に
保持されたままの状態になる。That is, the present invention relates to a method for producing a mixed powder of finely divided iron ore and a fine solid reducing material or a mixed powder of fine iron ore and a fine powder auxiliary material and a fine solid reducing material, Are piled in a state where they are not directly in contact with the hearth that moves horizontally and are reduced, and then the reduced iron is melted. As an example, FIGS. 3 (a), (b) and (c)
FIG. 3 is an explanatory diagram showing the state of loading raw materials on a hearth suitable for the present invention and the change when molten reduced iron is melted. In FIG. 3, 1 is a mixed powder of fine iron ore and fine solid reducing material (or fine iron ore and fine powder auxiliary material and fine solid reducing material), 2 is a layer of fine solid reducing material, 3 is a moving hearth, Is reduced iron from which gangue and ash are separated, and 5 is slag. When the raw materials are stacked and heated by radiant heat from above as shown in Fig. 3 (a) and (b), the fine iron ore is reduced by the action of the mixed fine solid reducing material, and the fine iron ore is reduced Become iron. Further, ash remains from the powdered solid reducing material used as the reducing material. The auxiliary material is added to facilitate melting when reducing iron and ash are melted, and examples thereof include limestone, fluorite, serpentine, and dolomite. Prior to melting, they have undergone evaporation of water of crystallization and some decomposition reactions (for example, CaCO 3, which is a main component of limestone, has been thermally decomposed into CaO), but it remains solid. Upon further heating, they begin to melt and separate into molten iron and slag. At this time, the mixed powder of the fine iron ore and the fine solid reducing material or the mixed powder of the fine iron ore, the fine solid reducing material, and the fine powder auxiliary material are scattered in a single layer of the fine solid powder reducing material, and Since it was not directly in contact with the horizontally moving hearth, the molten iron and molten slag agglomerated in each of the small compartments that were scattered, and formed a single layer of the powdered solid reducing material. Lumped reduced iron is formed on the top. Normally, since the specific gravity of molten iron and molten slag is greater than that of the layer of the solid fine powder alone, it is conceivable that the molten iron and molten slag may enter under the layer of the single powder solid reduced material. Since the mixed powder with the solid reducing material (or the mixed powder of the fine iron ore and the powdered auxiliary material and the fine solid reducing material) was scattered in the single layer of the fine solid reducing material, the molten iron and the molten slag Each one is small and is held on a single layer of powdered solid reducing material by the action of surface tension.
【００１３】この状態で移動炉床上で冷却器によって溶
融鉄、溶融スラグを冷却すると脈石・灰分を分離した還
元鉄とスラグが粉固体還元材の単体の層の上に浮いた状
態で、かつ、点在させていた小区画単位ごとの塊にな
る。かくして、凝固した還元鉄、スラグは粉固体還元材
の単体の層の存在によって移動炉床から離れた状態にあ
り、かつ、ひとつひとつが小さな塊であることから容易
に炉外に排出できる。ここで用いる粉鉄鉱石は篩い目８
mm以下、粉副原料は篩い目８mm以下および粉固体還元材
は篩い目８mm以下のものを用いることが好ましい。In this state, when the molten iron and the molten slag are cooled on the moving hearth by the cooler, the reduced iron and the slag separated from the gangue and ash are floated on the single layer of the powdered solid reducing material, and , It becomes a lump for each small block unit scattered. Thus, the solidified reduced iron and slag are separated from the moving hearth by the presence of a single layer of the powdered solid reducing material, and can be easily discharged outside the furnace because each is a small lump. The fine iron ore used here is sieve 8
mm or less, the powder auxiliary material preferably has a sieve of 8 mm or less, and the powder solid reducing material preferably has a sieve of 8 mm or less.
【００１４】粉鉄鉱石と粉固体還元材との混合粉中の粉
固体還元材として灰分のほとんどないピッチコークスの
使用も考えられる。その場合、この発明での灰分除去の
概念はなくなるが鉱石の脈石を分離する作用は同じであ
る。また、粉固体還元材の単体の層に粘結性のある石炭
を使用した場合、溶融鉄、溶融スラグが形成される温度
より低い温度で溶融し、コークス化するが、溶融鉄、溶
融スラグが形成される温度では既に固体状態にあり、上
記作用を発揮することができる。It is also conceivable to use pitch coke having almost no ash as a solid powder reducing material in a mixed powder of fine iron ore and a solid powder reducing material. In that case, the concept of ash removal in the present invention disappears, but the action of separating ore gangue is the same. In addition, when caking coal is used for a single layer of the powdered solid reducing material, it melts at a temperature lower than the temperature at which molten iron and molten slag are formed and coke, but the molten iron and molten slag are At the temperature at which it is formed, it is already in a solid state, and can exhibit the above-mentioned effects.
【００１５】石炭チャー、コークス、一般炭、無煙炭の
１種または２種以上の混合物は通常10％程度の灰分を含
んでいるが、この発明ではこれらの粉固体還元材を有利
に使用できるものであり、これらを粉固体還元材として
使用するとき、灰分除去の観点でこの発明を適用する意
義が大きい。なお、混合粉中の粉固体還元材と単体の層
の粉固体還元材とは同種であっても異種であってもよ
い。[0015] One or more of coal char, coke, steam coal and anthracite usually contains about 10% of ash. In the present invention, these powdered solid reducing materials can be advantageously used. Yes, when these are used as powdered solid reducing materials, the significance of applying the present invention from the viewpoint of ash removal is significant. The powdered solid reducing material in the mixed powder and the powdered solid reducing material in the single layer may be the same or different.
【００１６】[0016]
【実施例】回転する直径2.2mの炉床と炉床上方にバーナ
ーがあり、それら全体を炉体で覆った、図４に示す回転
炉床炉を用い、以下の操業を試験的に行った。EXAMPLE A rotary hearth furnace as shown in FIG. 4 was used in which the following operations were carried out on a trial basis with a 2.2 m-diameter rotating hearth and a burner above the hearth, the whole of which was covered with a furnace body. .
【００１７】ここで、図４において、６は上面にアルミ
ナ系耐火物を張った移動（回転）炉床、７はスクリュー
型の排出装置、８は装入装置（炉床への原料積み付け装
置）、９は炉体、10はバーナーであり、12は還元鉄を冷
却して取り出すために排出口前に設置した冷却器であ
る。供給口における原料の積み付けは、装入装置８によ
り粉鉄鉱石、粉副原料および粉固体還元材などの原料
を、図５〜８の原料積み付け方法の説明図に示すように
４種類の条件でそれぞれ移動（回転）炉床上に積み付け
た。図５〜８において、１は粉鉄鉱石および粉副原料と
粉固体還元材との混合粉、２は粉固体還元材および６は
移動（回転）炉床である。In FIG. 4, reference numeral 6 denotes a moving (rotating) hearth having an alumina-based refractory on its upper surface, reference numeral 7 denotes a screw-type discharging device, and reference numeral 8 denotes a charging device (a device for stacking raw materials on the hearth). ), 9 is a furnace body, 10 is a burner, and 12 is a cooler installed in front of the discharge port for cooling and taking out the reduced iron. The loading of the raw materials at the supply port is performed by charging the raw materials such as fine iron ore, fine powder auxiliary materials, and fine powder solid reducing material by the charging device 8 as shown in FIGS. Each condition was loaded on a moving (rotating) hearth. 5 to 8, reference numeral 1 denotes a mixed powder of fine iron ore and powder auxiliary materials and a fine powder solid reducing material; 2, a fine powder solid reducing material; and 6, a moving (rotating) hearth.
【００１８】粉鉄鉱石には脈石分（SiO2, Al2O3 等) を
７％以上含有する表１に示す成分組成のものを用い、粉
副原料には石灰石を用い、そして粉固体還元材には灰分
が６〜13％含有する表２に示す４種類の成分組成のもの
を用い、これらは篩い目３mm以下に調整して用いた。The fine iron ore used has a composition shown in Table 1 containing at least 7% of gangue (SiO 2 , Al 2 O 3, etc.). As the reducing material, those having four kinds of component compositions shown in Table 2 containing 6 to 13% of ash content were used, and these were adjusted to a sieve of 3 mm or less.
【００１９】[0019]
【表１】 [Table 1]
【００２０】[0020]
【表２】 実験条件と操業結果とをまとめて表３に示す。[Table 2] Table 3 summarizes the experimental conditions and operation results.
【００２１】[0021]
【表３】 [Table 3]
【００２２】なお表中、混合粉の項の脈石＋灰分とは混
合粉中の含有量であって、粉鉄鉱石の脈石、粉固体還元
材中の灰分のほか粉副原料（石灰石）中のCaO 分も含ん
でいる。In the table, gangue + ash in the mixed powder means the content in the mixed powder, which is the gangue of the iron ore, the ash in the powdered solid reducing material, and the powdered auxiliary material (limestone). Also contains CaO content.
【００２３】表３において、実験番号１〜10はこの発明
の適合例である。いずれの条件においても炉床の耐火物
の損傷がなく、製品排出のトラブルもなく、還元鉄の鉄
回収率が97.4％以上と脈石、灰分が除去された状態で回
収できた。In Table 3, Experiment Nos. 1 to 10 are applicable examples of the present invention. Under any conditions, the refractory of the hearth was not damaged, and there was no trouble in product discharge. The iron recovery rate of reduced iron was 97.4% or more, and it was recovered with gangue and ash removed.
【００２４】一方、実験番号11〜12の比較例は図７（条
件３）の積み付け方法であって、炉床の耐火物の上に直
接混合粉が接する状態で積み付けられている。このよう
な状態の積み付けで、脈石、灰分除去操作のため還元
鉄、灰分を溶融させたところ、スラグ、溶融鉄が炉床の
耐火物の溶着し、耐火物を侵食したとともに、その後の
冷却操作でスラグ、溶融鉄が炉床の耐火物にそのまま固
着してしまい、排出装置による製品の排出が不能になっ
た。On the other hand, the comparative examples of Experiment Nos. 11 and 12 are the stacking method of FIG. 7 (condition 3), in which the mixed powder is stacked directly on the refractory of the hearth. In this state of stacking, gangue, reduced iron and ash were melted for ash removal operation, slag and molten iron were deposited on the refractory of the hearth, eroded the refractory, and During the cooling operation, the slag and the molten iron adhered directly to the refractory on the hearth, making it impossible to discharge the product using the discharge device.
【００２５】また、実験番号13の比較例は図８（条件
４）の積み付け方法であって、粉固体還元材の単体の層
の上全面に混合粉を層状に積み付けたものである。この
積み付けで脈石、灰分除去操作のため還元鉄、灰分を溶
融させたところ、スラグ、溶融鉄が共に大きな板のよう
な状態になり、表面張力の作用が自重に対して効力が低
下するため、一部の場所において溶融鉄やスラグが粉固
体還元材の単体の層の下に潜り込み、直接炉床の耐火物
に接触してしまった。よって、その部分の耐火物を侵食
したとともに、その後の冷却操作でスラグ、溶融鉄が炉
床の耐火物にそのまま固着してしまい、排出装置による
製品の排出が不能になった。The comparative example of Experiment No. 13 is the stacking method of FIG. 8 (condition 4), in which the mixed powder is stacked in a layer on the entire surface of a single layer of the powdered solid reducing material. When the reduced iron and ash are melted for the gangue and ash removal operation by this stacking, both the slag and the molten iron become in a state of a large plate, and the effect of the surface tension is less effective against its own weight. As a result, in some places, molten iron and slag sunk under the single layer of the powdered solid reducing material and directly contacted the refractory on the hearth. Therefore, the refractory material in that portion was eroded, and slag and molten iron were directly adhered to the refractory material in the hearth in the subsequent cooling operation, so that the discharge device could not discharge the product.
【００２６】さらに、実験番号14の比較例は実験番号13
と同じ積み付け方法である。この積み付けで、還元鉄、
灰分を溶融させたところ、運良く、実験番号13のような
粉固体還元材の単体の層の下に溶融鉄やスラグが潜り込
むようなことはなかったが、冷却過程での収縮で部分的
な割れはあるものの冷却後のスラグ、還元鉄は大きな板
状であり、それらの排出が困難であった。Further, the comparative example of Experiment No. 14 is Experiment No. 13
It is the same packing method as. With this packing, reduced iron,
When the ash was melted, luckily, molten iron and slag did not sunk under the single layer of the powdered solid reducing material as in Experiment No. 13, but partial shrinkage during the cooling process caused Although cracked, the slag and reduced iron after cooling were in a large plate shape, and it was difficult to discharge them.
【００２７】なお、この発明の変形例として、図９のよ
うな積み付け方法も考えられる。この場合、排出口に出
てくる冷却後のスラグ、還元鉄は回転炉床の半径方向に
伸びた棒状になるため排出装置を図10のような構造のも
のを用いることが適していると考えられる。なお、図10
において６は移動（回転）炉床、９は炉体および13は変
形例の積み付け時に使用する排出装置である。As a modification of the present invention, a stacking method as shown in FIG. 9 can be considered. In this case, since the cooled slag and reduced iron coming out of the discharge port become rods extending in the radial direction of the rotary hearth, it is considered appropriate to use a discharge device with a structure as shown in Fig. 10. Can be Note that FIG.
In the figure, 6 is a moving (rotating) hearth, 9 is a furnace body, and 13 is a discharge device used at the time of packing in a modified example.
【００２８】[0028]
【発明の効果】この発明は、移動型炉床炉での鉄鉱石の
還元操業において、炉床上に、粉固体還元材を介して、
炉床に直接接触しないように粉鉄鉱石と粉固体還元材と
を含む混合粉を小区画化して点在させ、還元された還元
鉄を炉床上で溶融させるものであり、この発明によれ
ば、簡便な設備を用いながらも、設備を損傷させること
なく、また、円滑な操業も確保しながら、脈石、灰分の
混入がない還元鉄、すなわち電気炉に供して評価の高い
還元鉄を得ることができる。According to the present invention, in a reduction operation of iron ore in a movable hearth furnace, a fine solid reducing material
According to the present invention, a mixed powder containing fine iron ore and fine solid reducing material is divided into small sections so as not to directly contact the hearth, and the reduced powder is melted on the hearth. , Using simple equipment, without damaging the equipment and ensuring smooth operation, reducing iron without gangue and ash contamination, that is, using it in an electric furnace to obtain highly evaluated reduced iron be able to.
【図１】回転炉床炉の説明図である。FIG. 1 is an explanatory view of a rotary hearth furnace.
【図２】移動炉床上に鉄鉱石と固体還元材との混合粉を
直接積み付けた場合の説明図。FIG. 2 is an explanatory diagram of a case where a mixed powder of iron ore and a solid reducing material is directly stacked on a moving hearth.
【図３】この発明に適合する炉床上への原料積み付け状
態と還元鉄を溶融したときの変化の説明図である。FIG. 3 is an explanatory diagram of a state in which raw materials are stacked on a hearth and changes when reduced iron is melted according to the present invention.
【図４】実施例で用いた回転炉床炉の説明図である。FIG. 4 is an explanatory view of a rotary hearth furnace used in an example.
【図５】実施例で採用した原料の積み付け方法の説明図
である（条件１：適合例）。FIG. 5 is an explanatory view of a method of packing raw materials adopted in Examples (Condition 1: conforming example).
【図６】実施例で採用した原料の積み付け方法の説明図
である（条件２：適合例）。FIG. 6 is an explanatory diagram of a method of packing raw materials adopted in Examples (condition 2: conforming example).
【図７】実施例で採用した原料の積み付け方法の説明図
である（条件３：比較例）。FIG. 7 is an explanatory diagram of a method of packing raw materials used in Examples (condition 3: comparative example).
【図８】実施例で採用した原料の積み付け方法の説明図
である（条件４：比較例）。FIG. 8 is an explanatory diagram of a method of packing raw materials used in Examples (condition 4: comparative example).
【図９】この発明に適合する変形例の積み付け条件の説
明図である。FIG. 9 is an explanatory view of a stacking condition of a modified example conforming to the present invention.
【図１０】この発明に適合する変形例の積み付け時に使
用する排出装置の説明図である。FIG. 10 is an explanatory view of a discharge device used at the time of stacking a modified example conforming to the present invention.
１ 粉鉄鉱石と粉固体還元材との混合粉（または粉鉄鉱
石および粉副原料と粉固体還元材副原料との混合粉） ２ 粉固体還元材単体の層 ３ 移動炉床 ４ 脈石、灰分が分離された還元鉄 ５ スラグ ６ 移動（回転）炉床 ７ 排出装置 ８ 装入装置（炉床への原料積み付け装置） ９ 炉体 １０ バーナー １１ 粉鉄鉱石と粉固体還元材との混合粉からなる層 １２ 冷却器 １３ 変形例の積み付け時に使用する排出装置Reference Signs List 1 mixed powder of fine iron ore and fine solid reducing material (or mixed powder of fine iron ore and fine powder auxiliary material and fine powder solid reducing material auxiliary material) 2 layer of simple fine powder reducing material 3 moving hearth 4 gangue, Reduced iron from which ash has been separated 5 Slag 6 Moving (rotating) hearth 7 Discharge device 8 Charging device (device for stacking raw materials on the hearth) 9 Furnace body 10 Burner 11 Mixing of iron ore and fine solid reducing material Layer composed of powder 12 Cooler 13 Discharge device used when packing the modified example
Claims (2)
料を、水平に移動する炉床上に層状に積み付け、炉内上
方からの輻射伝熱によって鉄鉱石の還元を行う移動型炉
床炉の操業方法において、 粉鉄鉱石と粉固体還元材との混合粉または粉鉄鉱石およ
び粉副原料と粉固体還元材との混合粉を該炉床上に、粉
固体還元材を介して炉床に直接接触しないようにして小
区画化して点在させ、還元された還元鉄を該炉床上で少
なくとも一度は溶融させることを特徴とする移動型炉床
炉の操業方法。A moving type in which raw materials mainly composed of fine iron ore and fine solid reducing material are stacked in layers on a horizontally moving hearth, and the iron ore is reduced by radiant heat transfer from inside the furnace. In the method of operating a hearth furnace, a mixed powder of fine iron ore and fine solid reducing material or a mixed powder of fine iron ore and fine powder auxiliary material and fine solid reducing material is placed on the hearth via a fine solid reducing material. A method for operating a movable hearth furnace, characterized in that the reduced reduced iron is melted at least once on the hearth, being divided into small sections so as not to directly contact the hearth.
ス、一般炭または無煙炭のうちから選ばれる１種または
２種以上の混合粉である請求項１に記載の移動型炉床炉
の操業方法。2. The method for operating a movable hearth furnace according to claim 1, wherein the powdered solid reducing material is one or more mixed powders selected from coal char, coke, steam coal and anthracite. .
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26541097A JP3449195B2 (en) | 1997-09-30 | 1997-09-30 | Operating method of mobile hearth furnace |
| US09/308,869 US6270552B1 (en) | 1997-09-30 | 1998-03-27 | Rotary hearth furnace for reducing oxides, and method of operating the furnace |
| KR10-1999-7004742A KR100388329B1 (en) | 1997-09-30 | 1998-03-27 | A movable hearth furnace for reducing oxides, and method of operating the furnace |
| EP98911061A EP0969105B1 (en) | 1997-09-30 | 1998-03-27 | Method of operating a movable hearth furnace for reducing oxides |
| BR9806224-7A BR9806224A (en) | 1997-09-30 | 1998-03-27 | Rotary hearth furnace to reduce oxides and its operating method. |
| IDW990477A ID22491A (en) | 1997-09-30 | 1998-03-27 | ROTATING SEA FUNCTION FOR SEED OXIDE AND OPERATION METHOD OF ITS |
| PCT/JP1998/001399 WO1999016913A1 (en) | 1997-09-30 | 1998-03-27 | Rotary hearth furnace for reducing oxides, and method of operating the furnace |
| EP06025985A EP1770175A1 (en) | 1997-09-30 | 1998-03-27 | Rotary hearth furnace for reducing oxides |
| DE69838246T DE69838246T2 (en) | 1997-09-30 | 1998-03-27 | METHOD FOR OPERATING A MOVABLE OVEN FOR REDUCING OXIDES |
| MYPI98001419A MY118376A (en) | 1997-09-30 | 1998-03-31 | Rotary hearth furnace for reducing oxides and operating method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26541097A JP3449195B2 (en) | 1997-09-30 | 1997-09-30 | Operating method of mobile hearth furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11106815A true JPH11106815A (en) | 1999-04-20 |
| JP3449195B2 JP3449195B2 (en) | 2003-09-22 |
Family
ID=17416787
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26541097A Expired - Fee Related JP3449195B2 (en) | 1997-09-30 | 1997-09-30 | Operating method of mobile hearth furnace |
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| Country | Link |
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| JP (1) | JP3449195B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009091664A (en) * | 2008-12-15 | 2009-04-30 | Kobe Steel Ltd | Method for producing granular metal iron |
| JP4572435B2 (en) * | 1999-12-24 | 2010-11-04 | Ｊｆｅスチール株式会社 | Method for producing reduced iron from iron-containing material |
-
1997
- 1997-09-30 JP JP26541097A patent/JP3449195B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4572435B2 (en) * | 1999-12-24 | 2010-11-04 | Ｊｆｅスチール株式会社 | Method for producing reduced iron from iron-containing material |
| JP2009091664A (en) * | 2008-12-15 | 2009-04-30 | Kobe Steel Ltd | Method for producing granular metal iron |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3449195B2 (en) | 2003-09-22 |
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