JP2001234256A - Operating method for rotary hearth type reducing furnace and molding of reducing furnace raw material - Google Patents
Operating method for rotary hearth type reducing furnace and molding of reducing furnace raw materialInfo
- Publication number
- JP2001234256A JP2001234256A JP2000372019A JP2000372019A JP2001234256A JP 2001234256 A JP2001234256 A JP 2001234256A JP 2000372019 A JP2000372019 A JP 2000372019A JP 2000372019 A JP2000372019 A JP 2000372019A JP 2001234256 A JP2001234256 A JP 2001234256A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- rotary hearth
- reduction furnace
- raw material
- mixture
- 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.)
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Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、回転炉床式還元炉
を用いて、酸化金属を還元する方法、および、金属の精
錬業および加工業において発生する金属酸化物を含むダ
ストおよびスラジを還元処理する方法に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing metal oxides using a rotary hearth reduction furnace, and to reduce dust and sludge containing metal oxides generated in the metal refining and processing industries. It relates to the method of processing.
【０００２】[0002]
【従来の技術】還元鉄や合金鉄を製造するプロセスとし
ては各種のものがあるが、この内で、生産性の高いプロ
セスとして、回転炉床式還元炉があり、金属の還元が実
施されている。回転炉床式還元炉は、固定した耐火物の
天井および側壁の下で、中央部を欠いた円盤状の耐火物
の炉床がレールの上を一定速度で回転する型式の焼成炉
（以下、回転炉と称す）を主体とするプロセスであり、
酸化金属の還元に用いられる。一般的に、円盤状炉床の
直径は１０メートルから５０メートルかつ、幅は２メー
トルから６メートルである。2. Description of the Related Art There are various processes for producing reduced iron and alloyed iron. Among them, there is a rotary hearth type reduction furnace as a process having high productivity, and reduction of metal is carried out. I have. The rotary hearth reduction furnace is a type of firing furnace in which a disk-shaped refractory hearth lacking a central portion rotates below a fixed refractory ceiling and side walls at a constant speed on rails. Process).
Used for reduction of metal oxide. Generally, the diameter of the disk hearth is 10 to 50 meters and the width is 2 to 6 meters.
【０００３】原料の酸化金属を含む粉体は、炭素系の還
元剤と混合された後、原料ペレットにされて、回転床炉
に供給される。原料ペレットはこの炉床上に敷きつめら
れており、原料ペレットが炉床上に相対的に静置されて
いることから、原料ペレットが炉内で崩壊しづらいとい
った利点があり、耐火物上に粉化した原料が付着する問
題が無く、また、塊の製品歩留が高いと言った長所があ
る。また、生産性が高く、安価な石炭系の還元剤や粉原
料を使用できる、と言った理由から、近年、実施される
例が増加している。[0003] A powder containing a metal oxide as a raw material is mixed with a carbon-based reducing agent, then formed into raw material pellets and supplied to a rotary bed furnace. The raw material pellets are spread on this hearth, and since the raw material pellets are relatively stood on the hearth, there is an advantage that the raw material pellets are hard to collapse in the furnace, and the raw material pellets are powdered on the refractory. There is an advantage that there is no problem of raw material sticking and that the product yield of lumps is high. In recent years, more and more examples have been implemented because of the fact that high productivity and inexpensive coal-based reducing agents and powdered raw materials can be used.
【０００４】さらに、回転炉床法は、高炉、転炉、電気
炉から発生する製鉄ダストや圧延工程でのシックナース
ラジの還元と不純物除去の処理にも有効であり、ダスト
処理プロセスとしても使用され、資源リサイクルに有効
なプロセスである。Further, the rotary hearth method is also effective for the treatment of reduction and removal of impurities from the blast furnace, converter, electric furnace, and the thinner sludge in the rolling process, and is also used as a dust treatment process. This is an effective process for resource recycling.
【０００５】回転炉床法の操業の概略は以下の通りであ
る。まず、原料である鉱石やダスト、スラジの金属酸化
物にこの酸化物の還元に必要な量の炭素系還元剤を混合
した後、パンペレタイザー等の造粒機にて、平均水分が
約１０％となるように、水をかけながら、数mmから十数
mmのペレットを製造する。原料の鉱石や還元剤の粒径が
大きい場合は、ボールミル等の粉砕機で粉砕した後に、
混練して、造粒する。[0005] The outline of the operation of the rotary hearth method is as follows. First, after mixing an amount of a carbon-based reducing agent necessary for the reduction of the ore, dust, and sludge metal oxides as raw materials with a granulating machine such as a pan pelletizer, the average water content is reduced to about 10%. So that it is a few millimeters
Produce mm pellets. If the particle size of the raw material ore or reducing agent is large, after crushing with a crusher such as a ball mill,
Knead and granulate.
【０００６】当該ペレットは回転炉の炉床上に層状に供
給され、急速に加熱され、５〜２０分間、１１００〜１
３００℃の高温で焼成される。この際に、ペレットに混
合されている還元剤により酸化金属が還元され、金属が
生成する。金属化率は還元される金属により異なるが、
鉄、ニッケル、マンガンでは、９５％以上、還元しづら
いクロムでも５０％以上となる。また、製鉄業から発生
するダストを処理する場合は、還元反応に伴い、亜鉛、
鉛、アルカリ金属、塩素、等の不純物が揮発除去される
ことから、ダストを高炉や電気炉にリサイクルすること
が容易となる。[0006] The pellets are supplied in layers on the hearth of a rotary furnace, heated rapidly, and heated to 1100-1 for 5-20 minutes.
It is fired at a high temperature of 300 ° C. At this time, the metal oxide is reduced by the reducing agent mixed in the pellet, and a metal is generated. The metallization rate depends on the metal being reduced,
For iron, nickel, and manganese, the content is 95% or more, and even for chromium that is difficult to reduce, the content is 50% or more. Also, when processing dust generated from the steel industry, zinc,
Since impurities such as lead, alkali metal, and chlorine are volatilized and removed, dust can be easily recycled to a blast furnace or an electric furnace.
【０００７】このように、回転炉床を用いる金属の還元
方法および製鉄ダストの還元処理方法においては、原料
と還元剤をペレットにすることが条件で、原料の事前処
理として、原料の酸化金属の粉体と還元剤の混合物を造
粒性の良い状態にすることが重要であり、原料の事前粉
砕やボールミルでの混練等の種々の方法が行われてい
る。[0007] As described above, in the method for reducing metal using a rotary hearth and the method for reducing ironmaking dust, the raw material and the reducing agent are pelletized, and the pretreatment of the raw material is performed by reducing the metal oxide of the raw material. It is important to bring the mixture of the powder and the reducing agent into a state of good granulation, and various methods such as pre-grinding of the raw materials and kneading in a ball mill have been performed.
【０００８】[0008]
【発明が解決しようとする課題】前述のように、従来法
を用いた回転炉床法での酸化金属の還元方法は、生産性
や製造費用の面で優れており、経済的に金属を製造する
方法である。しかし、従来技術では、原料と還元剤を混
合して、これをペレットにすることが重要であった。そ
のために、造粒性能の高い原料を選択するか、高価な粉
砕機を設置して、原料を粉砕することにより造粒性を向
上させることが必要であり、このための費用がかかる問
題があった。As described above, the method of reducing metal oxide by the rotary hearth method using the conventional method is excellent in productivity and production cost, and economically produces metal. How to However, in the prior art, it was important to mix a raw material and a reducing agent and to make this a pellet. Therefore, it is necessary to select a raw material having high granulation performance or to install an expensive crusher to improve the granulation by crushing the raw material. Was.
【０００９】つまり、原料として鉄鉱石等の鉱石を使用
する場合は、一般には、原料鉱石の粒径が大きいため、
平均粒径が数十から百ミクロン程度になるように粉砕し
た後、造粒して、ペレットを製造していた。その結果、
粉砕工程の設備が高価であり、また、粉砕機の運転のた
めの電力がかかることや粉砕機器の磨耗に伴う整備費用
がかかるといった欠点があった。That is, when using an ore such as iron ore as a raw material, the particle size of the raw ore is generally large.
After pulverizing so that the average particle size becomes about several tens to hundreds of microns, granulation is performed to produce pellets. as a result,
There are drawbacks in that the equipment for the pulverizing process is expensive, that power is required for operating the pulverizer, and that maintenance costs are required due to wear of the pulverizer.
【００１０】したがって、粉砕の費用を節約するため
に、微粉の原料を使用することがあるが、粒径の制約等
の原料選択性が厳しく、汎用的な方法ではなかった。そ
こで、湿式選鉱後の微粉の鉱石を使用したり、高炉や転
炉のシックナーダスト、圧延工程でのスケールピットの
スラジや酸洗工程での沈殿スラジ等を使用することが有
効である。しかし、この場合でも、原料の含有水分が多
すぎて造粒しづらいといった問題があった。すなわち、
これらの原料は粒径が１ミクロン以下から百ミクロン程
度の微粉であり、その結果、水分を含んだ状態では、こ
れらは汚泥状となりやすく、真空脱水機やフィルタープ
レスでの脱水した後でも、水分が２０％から５０％にし
かならない。ペレットの製造の際は、原料の含有水分
は、８から１３質量％が適当であり、これらの湿式法で
集めた原料は、水分が多すぎて、そのままでは造粒でき
なかった。[0010] Therefore, in order to save the cost of pulverization, a raw material of fine powder is sometimes used, but the raw material selectivity is severe due to restrictions on particle size and the like, and it is not a general-purpose method. Therefore, it is effective to use fine ore after the wet beneficiation, to use thickener dust in a blast furnace or a converter, to use sludge of scale pits in a rolling process, or to precipitate sediment in a pickling process. However, even in this case, there was a problem that the raw material contained too much water to make granulation difficult. That is,
These raw materials are fine powders having a particle size of 1 micron or less to about 100 microns. As a result, when they contain moisture, they tend to be sludge-like, and even after dehydration with a vacuum dehydrator or filter press, the moisture content is low. Is only 20% to 50%. In the production of pellets, the water content of the raw material is suitably from 8 to 13% by mass, and the raw materials collected by these wet methods have too much water and could not be granulated as they are.
【００１１】この問題の解決のためには、これらの湿式
法で集めた原料を熱風等の熱源で完全に乾燥する方法が
ある。しかし、乾燥過程でこれらの粉原料が疑似凝集し
てしまい、そのままでは造粒することはできないため、
これを粉砕して、再度、微粒の状態にした後に、コーク
ス粉などとともに、加水して、造粒した後に、回転炉床
で、還元されていた。In order to solve this problem, there is a method of completely drying the raw materials collected by these wet methods using a heat source such as hot air. However, during the drying process, these powder raw materials are pseudo-agglomerated and cannot be granulated as they are,
This was pulverized and made into fine particles again, then watered together with coke powder and the like, granulated, and then reduced on a rotary hearth.
【００１２】その結果、これらの湿式法で集めた原料を
上記の方法で利用された場合でも、多量の熱源を用いて
乾燥した後に、再度水分を加えられるため、造粒時の水
分の蒸発に、再度、熱源が必要であり、経済的な金属の
還元方法ではなかった。As a result, even when these raw materials collected by the wet method are used in the above-described method, water is added again after drying using a large amount of heat source, so that evaporation of water during granulation can be prevented. Again, a heat source was required and was not an economical method of metal reduction.
【００１３】特に、製鉄業等の金属の精錬業や加工業で
発生するダストやスラジを湿式集塵機または沈殿槽から
集めた場合には、これらの発生物は、最大８０％の水分
を含有しており、これらの発生物を回転炉床法で還元処
理しようとする場合には、乾燥工程と乾燥後の粉砕処理
の問題が顕著であった。[0013] In particular, when dust and sludge generated in the metal refining and processing industries such as the steel making industry are collected from a wet dust collector or a sedimentation tank, these products contain a maximum of 80% of water. In the case where these products are subjected to reduction treatment by the rotary hearth method, the problems of the drying step and the pulverization treatment after the drying are remarkable.
【００１４】これらの問題を解決するために、例えば、
特開平１１−１２６１９号公報に示されるように、原料
を造粒せずに回転炉床式還元炉で使用する方法として、
原料を圧縮成形器でタイル状にして、これを回転炉床式
還元炉で使用する方法が提案されている。しかし、この
方法でも、やはり、水分を大量に含有した状態の原料を
使用することには問題があった。つまり、特開平１１−
１２６２４号公報の方法においても、タイル状にした原
料の水分を６〜１８％に調整する必要があった。百ミク
ロン程度の微粉が湿状態である場合は、通常の脱水機
で、脱水工程のみでは、これを水分１５〜３０質量％の
範囲にしか低減できなかった。つまり、この操業を実施
するためには、やはり、事前の脱水処理に加え、乾燥処
理が必要であり、このための複雑な水分制御が必要な問
題があった。In order to solve these problems, for example,
As shown in JP-A-11-12619, as a method of using a rotary hearth-type reduction furnace without granulating raw materials,
A method has been proposed in which a raw material is formed into a tile shape by a compression molding machine and used in a rotary hearth-type reduction furnace. However, this method still has a problem in using a raw material containing a large amount of water. That is, JP-A-11-
Also in the method of 12624, it was necessary to adjust the water content of the tiled raw material to 6 to 18%. When the fine powder of about 100 microns was in a wet state, it could only be reduced to a water content of 15 to 30% by mass with a normal dehydrator using only a dehydration step. In other words, in order to carry out this operation, a drying treatment is required in addition to a prior dehydration treatment, and there is a problem that complicated water control is required for this.
【００１５】さらに、タイル状の原料は、ハンドリング
が難しく、通常のベルトコンベア等の手段の搬送では、
搬送中の乗り継ぎ等の際に、タイルが粉々になる搬送上
の問題が生ずる。つまり、含水率が６〜１８％のタイル
状の原料は０. ５ｍから１ｍ程度の落下で、ほとんどの
ものが損傷する。その結果、このタイル状の原料装入の
ためには、特開平１１−１２６２１号公報に示されるよ
うな、タイル上の原料を炉内に静置するための複雑な装
入装置が必要であった。その結果、この設備の設置の設
備費用が高い等の問題も生じていた。また、このような
複雑な装入装置を１０００℃以上の高温部の近くに設置
することにより、装入装置の機器が熱変形を受けたり、
高温下での腐食を受けたりといった整備上の問題が大き
いものであった。[0015] Furthermore, the handling of the tile-shaped raw material is difficult.
At the time of connection during transportation or the like, a transportation problem that tiles are broken occurs. That is, most of tile-shaped raw materials having a water content of 6 to 18% are damaged by a drop of about 0.5 m to about 1 m. As a result, in order to charge the raw material in the form of a tile, a complicated charging device for allowing the raw material on the tile to stand still in the furnace as shown in Japanese Patent Application Laid-Open No. H11-12621 is required. Was. As a result, there have been problems such as a high facility cost for installing this facility. In addition, by installing such a complicated charging device near a high temperature portion of 1000 ° C. or higher, the device of the charging device may be subjected to thermal deformation,
Maintenance problems, such as corrosion at high temperatures, were significant.
【００１６】また、湿状態のタイル状の原料は、爆裂し
やすい問題もある。ペレットに比べれば、爆裂しずらい
が、特開平１１−１２６２１号公報の方法での水分の多
い条件である１２〜１８質量％では、やはり、爆裂しや
すいものである。これは、タイル状であると横方向への
水蒸気の移動はないことが原因である。つまり、タイル
状であると空間的に横方向が極端に長いため、水蒸気が
上下のみの方向に抜けていくため、通過抵抗が高くなっ
て、爆裂しやすいものであった。[0016] Further, there is a problem that the tile-shaped raw material in a wet state is liable to explode. Compared to pellets, it is difficult to explode, but it is still easy to explode at 12 to 18% by mass, which is a condition with a large amount of water according to the method of JP-A-11-12621. This is because there is no movement of water vapor in the lateral direction in the case of the tile shape. That is, in the case of the tile shape, since the horizontal direction is extremely long spatially, the water vapor escapes only in the up and down directions, so that the passage resistance is increased and the explosion easily occurs.
【００１７】このように、水分の多い粉体原料を乾燥す
ることなく、回転床炉にて、焼成還元する方法はのぞま
しい方法であるものの、高温の炉内で、水分の高い成形
体からは激しく水分が蒸発することから、当該成形体が
爆裂していた。その結果、成形体が粉化して、排ガス中
へのダストロスが大幅に増加する問題、塊製品歩留が極
端に悪化する問題等が生じていた。したがって、従来法
で水分の比較的高い状態の成形物を直接的に焼成還元す
ることは、経済的でなかった。As described above, although the method of calcining and reducing the powdery raw material having a high moisture content in a rotary bed furnace without drying it is a preferable method, the molded product having a high moisture content in a high-temperature furnace is violently removed. Since the moisture was evaporated, the molded article had exploded. As a result, there has been a problem that the molded product is powdered and dust loss into exhaust gas is significantly increased, and a problem that the yield of lump product is extremely deteriorated. Therefore, it is not economical to directly reduce the calcined product having a relatively high water content by the conventional method.
【００１８】以上のように、いずれの従来法でも、水分
を含んだ粉状態の原料を回転床炉で還元することには、
経済的な問題があり、この問題を解決する新しい技術が
求められていた。As described above, in any of the conventional methods, reducing the raw material in a powder state containing water in a rotary bed furnace requires:
There was an economic problem, and a new technology to solve this problem was required.
【００１９】[0019]
【課題を解決するための手段】本発明は、以下の（１）
から（１２）の通りである。 （１）酸化金属と炭素と水分を含む粉体の混合物を、水
分量を混合物全体の１５〜３０質量％になるように脱水
し、該混合物を圧縮成形により複数の円柱又は粒状の成
形体とした後、直接、還元炉内に投入して焼成還元する
ことを特徴とする回転炉床式還元炉の操業方法。 （２）粉体質量合計に対して水分を１．０倍以上含む状
態で、酸化金属と炭素を含む粉体を撹拌混合して、これ
を１６〜２６質量％の含有水分まで脱水装置で脱水した
後に、圧縮成形機で成形して製造した、粉体充填率が
０. ４３〜０. ５８の範囲である成形体を、雰囲気温度
が１１７０℃以下である炉内部分に投入して、その後に
１２００℃以上の温度で焼成還元することを特徴とする
回転炉床式還元炉の操業方法、 （３）脱水装置として、水分を含む状態の粉体を受ける
帯状のフィルター、および、当該フィルターを上下から
挟み込んで圧縮する双ロールを有する脱水機を用いるこ
とを特徴とする（１）又は（２）記載の回転炉床式還元
炉の操業方法、 （４）脱水装置として、縦型で下部に内側に狭くなるテ
ーパーを有する円筒形状である、水分を含む状態の粉体
の保持部とその内部にスクリュー式の粉体排出機構を有
し、当該保持部と当該粉体排出機構の差速が毎分２〜３
０回転であり、当該保持部に働く遠心力が５００Ｇ以上
の遠心式脱水機を用いることを特徴とする（１）又は
（２）記載の回転炉床式還元炉の操業方法。 （５）脱水装置として、水分を含む粉体を保持するフィ
ルターを両側から１０6N/m2以上の力で押しつける装置
を有する脱水装置を用いて脱水することを特徴とする
（１）又は（２）記載の回転炉床式還元炉の操業方法、 （６）含有水分が１６〜２６質量％の範囲、かつ、厚み
または径が３０ｍｍ以下である、酸化金属を含む粉体と
炭素を含む粉体の混合物を圧縮成形して製造した、粉体
充填率が０. ４３〜０. ５８の範囲である円柱または粒
状の成形体を、雰囲気温度が１１７０℃以下である炉内
部分に投入して、その後に１２００℃以上の温度で焼成
還元することを特徴とする回転炉床式還元炉の操業方
法、 （７）圧縮成形機として、湿状態の粉体を押し込む装置
と湿状態の粉体が通過する穴型からなる押し出し穴型式
の圧縮成形機を用いることを特徴とする（１）又は
（６）記載の回転炉床式還元炉の操業方法、 （８）圧縮成形機として、双ロール表面の凹状の型に湿
状態の粉体を押しつけて成形するブリッケト成形機を用
いることを特徴とする（１）又は（２）又は（６）記載
の回転炉床式還元炉の操業方法、 （９）厚みまたは径が３０ｍｍ以下のある酸化金属を含
む粉体と炭素を含む粉体の混合物を圧縮成形して製造し
た円柱または粒状の成形体を還元することを特徴とする
（６）記載の回転炉床式還元炉の操業方法、 （１０）酸化金属を含む粉体として、酸化鉄含有粉体を
用いる場合に、酸化鉄と化合している酸素の原子モル量
に対して固定炭素の原子モル量が０. ５〜１. ５倍の範
囲の成形体を還元することを特徴とする（１）又は
（２）又は（６）記載の回転炉床式還元炉の操業方法、 （１１）圧縮成形機で成形して製造した、円柱もしくは
粒状の成形体を、他の炉内部分よりも雰囲気温度を低下
させている部分に投入して、焼成還元することを特徴と
する（１）又は（２）又は（６）記載の回転炉床式還元
炉の操業方法、 （１２）酸化金属と炭素と水分を含む粉体の混合物を、
水分量を混合物全体の１５〜３０質量％になるように脱
水し、該混合物を圧縮成形により外形が３０ｍｍ以下の
円柱又は粒状の成形体としたことを特徴とする還元炉原
料の成形体、 （１３）含有水分が１６〜２６質量％の範囲、かつ、厚
みまたは径が３０ｍｍ以下である、酸化金属を含む粉体
と炭素を含む粉体の混合物を圧縮成形して製造して得
た、粉体充填率が０. ４３〜０. ５８の範囲である円筒
または粒状であることを特徴とする還元炉原料の成形
体、および、 （１４）酸化金属を含む粉体として、酸化鉄含有粉体を
用いる場合に、酸化鉄と化合している酸素の原子モル量
に対して固定炭素の原子モル量が０. ５〜１. ５倍の範
囲であることを特徴とする（１２）又は（１３）記載の
還元炉原料の成形体である。The present invention provides the following (1).
To (12). (1) A mixture of powder containing metal oxide, carbon and water is dehydrated so that the water content becomes 15 to 30% by mass of the whole mixture, and the mixture is subjected to compression molding to form a plurality of cylindrical or granular compacts. The method of operating a rotary hearth-type reduction furnace, wherein the method is directly introduced into the reduction furnace and calcined and reduced. (2) A powder containing metal oxide and carbon is stirred and mixed in a state where water is contained at least 1.0 times the total mass of the powder, and the mixture is dehydrated by a dehydrator to a water content of 16 to 26% by mass. After that, a compact having a powder filling rate in the range of 0.43 to 0.58, produced by molding with a compression molding machine, is charged into a furnace portion having an atmosphere temperature of 1170 ° C. or lower, and thereafter (3) a method of operating a rotary hearth-type reduction furnace characterized by firing and reducing at a temperature of 1200 ° C. or more; (1) The method of operating a rotary hearth-type reduction furnace according to (1) or (2), wherein a dehydrator having twin rolls for sandwiching and compressing from above and below is used; It has a cylindrical shape with a taper that narrows inward. , The holding portion of the powder state containing moisture and having a powder discharge mechanism of screw therein, per minute speed difference of the holding portion and the powder discharge mechanism is 2 to 3
The method for operating a rotary hearth type reduction furnace according to (1) or (2), wherein a centrifugal dehydrator having zero rotation and a centrifugal force acting on the holding unit of 500 G or more is used. (5) Dehydration is performed using a dehydrator having a device for pressing a filter holding moisture-containing powder from both sides with a force of 10 6 N / m 2 or more, as the dehydrator (1) or (1). 2) The method for operating a rotary hearth reduction furnace according to 2), (6) a powder containing metal oxide and a powder containing carbon and having a water content of 16 to 26% by mass and a thickness or diameter of 30 mm or less. A cylindrical or granular compact having a powder filling ratio in the range of 0.43 to 0.58, produced by compression-molding a mixture of the bodies, is charged into a furnace portion having an ambient temperature of 1170 ° C or lower. A method of operating a rotary hearth-type reduction furnace, which is followed by calcining and reducing at a temperature of 1200 ° C. or more. (7) As a compression molding machine, a device for injecting wet powder and a wet powder are used. Uses an extruded hole type compression molding machine consisting of a through hole die (8) The method for operating a rotary hearth-type reduction furnace according to (1) or (6), (8) as a compression molding machine, pressing a wet powder against a concave mold on the surface of the twin rolls and molding. (1) or (2) or (6), the method for operating a rotary hearth-type reduction furnace, (9) a powder containing a metal oxide having a thickness or a diameter of 30 mm or less. (10) The method for operating a rotary hearth type reduction furnace according to (6), wherein the columnar or granular compact produced by compression-molding a mixture of the powder containing the powder and carbon is reduced. When the iron oxide-containing powder is used as the powder containing, the fixed carbon has an atomic molar amount of 0.5 to 1.5 times the atomic molar amount of oxygen combined with iron oxide. The rotary hearth according to (1), (2) or (6), wherein the body is reduced. (11) A cylindrical or granular compact produced by molding with a compression molding machine is put into a part where the ambient temperature is lower than that in other furnace parts, and calcined and reduced. The method for operating a rotary hearth reduction furnace according to (1) or (2) or (6), wherein (12) a mixture of a powder containing metal oxide, carbon, and moisture,
A molded product of a reduction furnace raw material, characterized in that the mixture was dehydrated to a water content of 15 to 30% by mass of the whole mixture, and the mixture was compression-molded into a cylindrical or granular molded product having an outer shape of 30 mm or less; 13) Powder obtained by compression-molding a mixture of a powder containing metal oxide and a powder containing carbon and having a water content in the range of 16 to 26% by mass and a thickness or diameter of 30 mm or less. A compact of a reduction furnace raw material characterized by being cylindrical or granular having a body filling rate in the range of 0.43 to 0.58; and (14) an iron oxide-containing powder as a powder containing a metal oxide. (12) or (13), wherein the atomic molar amount of fixed carbon is in the range of 0.5 to 1.5 times the atomic molar amount of oxygen combined with iron oxide. )).
【００２０】[0020]
【発明の実施の形態】本発明は、水分を多く含む酸化金
属粉体を原料とする回転炉床式還元炉の操業方法を以下
の方法で行うものである。本発明に基づく、回転炉床法
による金属酸化物の還元プロセスを図１に示す。BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a rotating hearth type reduction furnace using a metal oxide powder containing a large amount of water as a raw material is operated by the following method. FIG. 1 shows a reduction process of a metal oxide by a rotary hearth method according to the present invention.
【００２１】水分を多く含み、スラリー状態となってい
る原料粉体を混合槽１で、撹拌装置２を用いて、撹拌混
合する。この原料粉体は、酸化金属を含む粉体と炭素を
含む粉体の混合物である。酸化金属を含む粉体は、微粉
の鉄鋼石であるペレットフィード、粉状態のマンガン鉱
石やクロム鉱石などがある。また、鉱石以外に、電気炉
ダスト、高炉ガス灰、転炉ダスト、鉄製品の酸洗時に発
生する中和スラジ、鉄鋼の熱間圧延のミルスケール等の
金属精錬や金属加工からの粉状態の発生物も使用可能で
ある。また、この原料粉には、還元剤として、炭素を主
体とする粉体、例えば、オイルコークス、粉コークス、
チャー、粉石炭、その他の固定炭素を含む粉体（以下、
炭素粉と記載）を混合する。The raw material powder containing a large amount of water and in a slurry state is stirred and mixed in the mixing tank 1 by using the stirring device 2. This raw material powder is a mixture of a powder containing metal oxide and a powder containing carbon. The powder containing metal oxide includes pellet feed, which is fine iron ore, and powdered manganese ore and chromium ore. In addition to ore, electric furnace dust, blast furnace gas ash, converter dust, neutralized sludge generated during pickling of iron products, and powdered state from metal refining and metal processing such as mill scale for hot rolling of steel. The product can also be used. Further, this raw material powder, as a reducing agent, a powder mainly composed of carbon, for example, oil coke, powder coke,
Char, pulverized coal, and other powders containing fixed carbon
Carbon powder).
【００２２】スラリー状態となっている原料粉体を、短
時間で均一に撹拌するためには、水分を多量に含んでい
る必要がある。本発明者らが、種々の実験を繰り返し
て、解明した結果では、原料粉体が水分を多く含んでい
ると撹拌性が良い。つまり、水分が多く、流動性が高け
れば、均一混合の時間が短くなるとともに、撹拌の動力
も少なくてすむ利点がある。水分含有率が粉体質量合計
に対して水分が１００％以上の場合は、スラリーの流動
性が高くなることを見いだした。つまり、混合を容易に
するためには、粉体質量合計に対して水分を１００％以
上含む状態で、酸化金属を含む粉体と炭素を含む粉体の
混合物を撹拌混合することが必要である。In order to stir the raw material powder in a slurry state uniformly in a short time, it is necessary to contain a large amount of water. As a result of the present inventors repeating various experiments and elucidating the results, it is found that the stirring property is good when the raw material powder contains a large amount of water. In other words, if the water content is high and the fluidity is high, there is an advantage that the time for the uniform mixing is shortened and the power for stirring is reduced. It has been found that when the water content is 100% or more of the total mass of the powder, the fluidity of the slurry increases. That is, in order to facilitate mixing, it is necessary to stir and mix a mixture of the powder containing metal oxide and the powder containing carbon in a state containing 100% or more of water with respect to the total mass of the powder. .
【００２３】スラリー状態で、粉体が容易に沈殿しない
ためには、粉体粒径は小さい方がよい。撹拌を強化すれ
ば、比較的大きい粉体も使用可能であるが、酸化金属粉
で１００ミクロン、炭素粉で１８０ミクロン以下、つま
り、混合比率を勘案すれば、総平均粒径が１２０ミクロ
ン以下であれば、１００質量％の水分の状態で、通常の
毎分１０〜３０回転程度の撹拌での均一に混合すること
が可能である。In order to prevent the powder from settling easily in the slurry state, the particle size of the powder is preferably small. If the stirring is strengthened, relatively large powder can be used, but metal oxide powder is 100 microns and carbon powder is 180 microns or less, that is, the total average particle diameter is 120 microns or less in consideration of the mixing ratio. If it is, it is possible to uniformly mix with a stirring of about 10 to 30 rotations per minute in a state of 100% by mass of water.
【００２４】当該スラリー状態となっている原料粉体を
スラリーポンプ３にて、脱水装置４に送る。脱水装置４
にて、含有水分が粉体質量の１５〜３０％、好ましくは
１６〜２３％の範囲になるように脱水する。粒径の粗い
粉体では含有水分１６〜２６質量％とすることは比較的
容易で、一般的な脱水機、例えば、真空脱水機、プレス
フィルター、遠心式デカンター、で対応できる。ただ
し、平均粒径が１２０ミクロン以下の微粉からなるスラ
リーの脱水の場合は、脱水物の水分を３０質量％以下、
好ましくは２６質量％以下とすることは、一般的な脱水
機では困難であり、特殊な脱水機を用いる。また、場合
によっては、幾つかの型式の脱水機を組み合わせて使用
することもある。The raw material powder in the slurry state is sent to the dewatering device 4 by the slurry pump 3. Dehydration device 4
In the above, dehydration is performed so that the water content is in the range of 15 to 30%, preferably 16 to 23% of the mass of the powder. It is relatively easy to adjust the water content to 16 to 26% by mass in the case of powder having a coarse particle size, and it can be dealt with by a general dehydrator such as a vacuum dehydrator, a press filter, and a centrifugal decanter. However, in the case of dewatering a slurry composed of fine powder having an average particle size of 120 microns or less, the water content of the dehydrated product is 30% by mass or less,
It is difficult to set the content to preferably 26% by mass or less with a general dehydrator, and a special dehydrator is used. In some cases, several types of dehydrators are used in combination.
【００２５】微粉体を用いる場合の脱水装置としては、
図３に記載されるスラリーを受けるフィルター２３、お
よび、当該フィルターを挟み込んで圧縮双ロール２５を
有する脱水機が良い。この脱水機では、エンドレスの帯
状に組み込まれているフィルター２３上に、スラリー２
６を流し、このフィルターを圧縮双ロール２６で挟み込
み脱水する。スラリーの水分が多い場合は、圧縮双ロー
ル２６の手前で、フィルターの下方の真空吸引装置２４
を用いて、スラリー中の水分を予備脱水すると効果的に
脱水ができる。As a dehydrator for using fine powder,
A dehydrator having a filter 23 for receiving the slurry shown in FIG. 3 and a compression twin roll 25 sandwiching the filter is preferable. In this dehydrator, the slurry 2 is placed on a filter 23 incorporated in an endless belt shape.
6, and the filter is sandwiched between the compression twin rolls 26 to be dehydrated. If the slurry has a high moisture content, the vacuum suction device 24 below the filter is provided in front of the compression twin roll 26.
By preliminarily dewatering the water in the slurry by using water, dewatering can be performed effectively.
【００２６】特に細かい粉体を含むスラリーの脱水装置
として、縦型の遠心式分離器を用いることも効果的であ
る。この遠心分離器は、下部に内側に狭くなるテーパー
を有する円筒のスラリー保持部とその内部にスクリュー
式の粉体排出機構を有し、当該スラリー保持部と当該粉
体排出機構の差速が毎分２〜３０回転であり、当該スラ
リー保持部に働く遠心力が５００Ｇ以上の遠心式脱水器
である。この脱水機は、１基当たりの能力は小さいもの
の、遠心力を用いるため、分離効率が良く、水分が多く
細かい粉体の脱水に向いている。特に、粒径が数ミクロ
ン〜４０ミクロンと小さい粉体に適用することは有効で
ある。It is also effective to use a vertical centrifugal separator as a dewatering device for a slurry containing fine powder. This centrifugal separator has a cylindrical slurry holding portion having a taper that narrows inward at the lower portion, and a screw-type powder discharging mechanism inside the slurry holding portion. The speed difference between the slurry holding portion and the powder discharging mechanism is constant. It is a centrifugal dehydrator with 2 to 30 rotations per minute and a centrifugal force acting on the slurry holding unit of 500 G or more. Although this dehydrator has a small capacity per unit, it uses centrifugal force, so it has a good separation efficiency and is suitable for dehydrating fine powder with a lot of moisture. In particular, it is effective to apply to a powder having a small particle size of several microns to 40 microns.
【００２７】また、脱水機として、スラリーを受けるフ
ィルターを両側から１０6N/m2以上の力で押しつける装
置を有する高圧プレス式脱水機を用いることも可能であ
るが、前出の双ロールを有する脱水機と比較すると、や
や脱水力が劣るため、１００ミクロン前後のやや粗い粉
体に使用することが望ましい。As the dehydrator, a high-pressure press type dehydrator having a device for pressing a filter for receiving slurry from both sides with a force of 10 6 N / m 2 or more can be used. Since the dewatering power is slightly inferior to that of a dehydrator having the same, it is desirable to use the powder for a slightly coarse powder of about 100 microns.
【００２８】次に、脱水されて、水分が１５〜３０％、
好ましくは１６〜２６質量％の範囲となった湿状態の粉
体をスラジ搬送コンベア５にて、圧縮成形機６に送り、
ここで成形する。圧縮成形機の機種としては、図４に示
す穴型に湿状態の粉体を押し込む型式の成形機（以降、
穴型ペレッターと称す）と図５に示す双ロール表面の凹
状の型に湿状態の粉体を押しつけて成形するブリッケト
成形機が、代表的な機種である。Next, it is dehydrated, and the water content is 15 to 30%.
The powder in the wet state, which is preferably in the range of 16 to 26% by mass, is sent to the compression molding machine 6 by the sludge conveying conveyor 5,
It is molded here. As a model of the compression molding machine, a molding machine of a type in which wet powder is pushed into a hole mold shown in FIG.
A typical example is a briquette molding machine which presses and wets a powder in a wet state against a concave mold on the surface of a twin roll shown in FIG.
【００２９】穴型ペレッターでは、図４に示されるよう
に、湿状態の成形体が円筒状に押し出される。原料は、
原料供給口２８から供給され、穴型３４が多数開いてい
る底プレート３３の上で、駆動装置２９、駆動動力伝達
機構３０、および、駆動シャフト３１によって駆動され
るローラー３２の押し込みにより、成形体３５となる。
他の方式では、胴部の中でスクリュー式の押し込み機構
があり、穴型の開いたプレートに押しつける型式のもの
などもある。ブリッケト成形機は、図５に示す装置であ
り、原料供給部３６から粉体を供給して、凹状くぼみ３
８があるローラー３７にて圧縮成形するものである。In the hole type pelleter, as shown in FIG. 4, a wet molded product is extruded into a cylindrical shape. Raw materials are
By pressing a driving device 29, a driving power transmission mechanism 30, and a roller 32 driven by a driving shaft 31, on a bottom plate 33 which is supplied from a raw material supply port 28 and has a large number of hole dies 34, the compact is formed. It becomes 35.
In another method, there is a screw-type push-in mechanism in the body, and there is a type in which the push-in mechanism is pressed against a plate having a hole. The briquette molding machine is an apparatus shown in FIG. 5, and supplies powder from a raw material supply section 36 to form a concave recess 3.
8 is compression-molded by a certain roller 37.
【００３０】これらの機種を選定した理由としては、成
形体の要求性状を満たす成形方法であることである。成
形体に要求される性状としては、主に、成形体が炉内で
の爆裂を起こさないこと、および、湿状態での落下強度
が高いことの２点である。The reason for selecting these models is that the molding method satisfies the required properties of the molded body. The properties required of the molded article are mainly two points that the molded article does not cause explosion in the furnace and that the drop strength in a wet state is high.
【００３１】従来法の成形方法であるパン式ペレット製
造方法では、粉体を傾斜部で転動することにより、表面
に新しい粉体層を作らせて、成形体を成長させる方法で
ある。この方法で製造したペレットは、粉体充填率が
０. ６５〜０. ７５程度と高く、かなり緻密な成形体で
ある。緻密な成形体は、回転炉床の原料供給部の９００
℃以上の部分で爆裂が起きやすい。直径が１０ｍｍ程度
のペレットでは、水分が３質量％以上では、炉内に供給
した直後に爆裂するものであった。なお、粉体充填率と
は、成形体の容積の内に含まれる粉体の容積の比率あ
る。In the conventional method of manufacturing a bread-type pellet, which is a molding method, a new powder layer is formed on the surface by rolling the powder at an inclined portion, and a molded body is grown. The pellets produced by this method have a high powder filling ratio of about 0.65 to 0.75 and are fairly dense compacts. The dense compact is 900 parts of the raw material supply section of the rotary hearth.
Explosion tends to occur at temperatures above ℃. In a pellet having a diameter of about 10 mm, when the moisture content was 3% by mass or more, the pellet exploded immediately after being supplied into the furnace. In addition, the powder filling rate is a ratio of the volume of the powder contained in the volume of the compact.
【００３２】本発明者らは、爆裂条件についての研究を
繰り返し、湿状態の成形体を直接炉内に供給した場合
に、成形体が爆裂を起こさないためには、成形体の粉体
充填密度が比較的低いことが重要であることを解明し
た。高温の炉内で、成形体内部の水分が急速に蒸発して
成形体内部の圧力が高まることを防止するには、粉体粒
子間に空隙が多いことが重要である。The present inventors have repeatedly studied explosion conditions, and in order to prevent the explosion of the molded article when the molded article in a wet state is directly supplied to the furnace, the powder filling density of the molded article is required. Is relatively important. It is important that there are many voids between the powder particles in order to prevent the moisture inside the compact from evaporating rapidly in a high-temperature furnace and increasing the pressure inside the compact.
【００３３】図６に、直径が２０mmの成形体での、粉体
充填率が１１７０℃の雰囲気中に投入した際の爆裂限界
水分に与える影響を示した。粉体充填率が低下すると爆
裂限界水分が上昇しており、粉体充填率が０. ５８以下
では、１８質量％の水分でも爆裂も部分的な粉化も起き
ず、２３〜２６質量％の水分でも、表面のはがれ現象は
生じたが、爆裂は生じなかった。さらに、粉体充填率が
０. ５５以下では、２３〜２６質量％程度の水分でも表
面のはがれ現象も起きなかった。つまり、爆裂防止の観
点からは、粉体充填率は０. ５８以下が望ましい。低粉
体充填率のものでは、爆裂限界水分が２３〜２６質量％
の状態で高止まりの傾向にある。FIG. 6 shows the effect of the compact having a diameter of 20 mm on the explosion limit moisture when charged into an atmosphere having a powder filling rate of 1170 ° C. When the powder filling rate decreases, the explosion limit moisture increases. When the powder filling rate is 0.58 or less, explosion and partial pulverization do not occur even with moisture of 18% by mass, and 23 to 26% by mass. Even with water, the surface peeled off, but did not explode. Further, when the powder filling rate was 0.55 or less, the surface peeling phenomenon did not occur even with moisture of about 23 to 26% by mass. That is, from the viewpoint of preventing explosion, the powder filling rate is desirably 0.58 or less. For those with a low powder filling rate, the explosion limit moisture is 23 to 26% by mass.
Tends to stay high in the state of.
【００３４】さらに、成形体の形状によって、爆裂の条
件が異なることも解明した。まず、タイル状の成形体
で、厚みが２０ｍｍ、長さと幅が１５０ｍｍのもので
は、粉体充填率が０. ５８の状態でも、水分が１７％で
爆裂が起きていた。一方、穴型ペレッターで製造した、
径が１５ｍｍで長さが２５ｍｍの円筒状の成形体では、
粉体充填率が０. ５８の状態は、水分が２５％まで爆裂
が起きなかった。また、ブリケット製造機で製造した、
厚みが２０ｍｍで辺が４０ｍｍのアーモンド状の成形体
では、粉体充填率が０. ５８の状態では、水分が２３％
まで爆裂が起きなかった。つまり、板状の成形体では、
爆裂しやすく、一方、円筒や粒状の成形体では、爆裂し
づらい特徴がある。そこで、本発明では、成形体の形状
を円筒か粒状のものに特定した。Further, it has been clarified that explosion conditions are different depending on the shape of the molded body. First, in the case of a tile-shaped molded product having a thickness of 20 mm and a length and a width of 150 mm, even when the powder filling rate was 0.58, explosion occurred at 17% of water. On the other hand, manufactured with a hole-type pelleter,
In a cylindrical molded body with a diameter of 15 mm and a length of 25 mm,
When the powder filling rate was 0.58, no explosion occurred until the water content reached 25%. Also, manufactured by briquette making machine,
An almond-shaped molded body having a thickness of 20 mm and sides of 40 mm has a water content of 23% when the powder filling rate is 0.58.
No explosion occurred until. In other words, in a plate-like molded body,
It is easy to explode, while a cylindrical or granular molded product has a characteristic that it is hard to explode. Therefore, in the present invention, the shape of the molded body is specified to be cylindrical or granular.
【００３５】穴型ペレッターとブリッケト成形機で製造
した成形体は、爆裂しづらいことの理由も解明した。穴
型ペレッターの成形体は円周側の表面は緻密になってい
るものの、円筒の切断面はルーズになっている。その結
果、含有水分が多い場合も、水蒸気の通過抵抗は小さい
ことから、爆裂が起きづらいことが解明された。条件に
よっては、穴型ペレッターでの成形体は含有水分が２６
質量％でも１１７０℃の炉内で爆裂しないこともあり、
最も耐爆裂性が良かった。ブリッケト成形機において
も、圧縮が厚み方向に一次元的であることから、ブリッ
ケト成形体の横側での密度が上がっておらず、そこか
ら、水蒸気が抜けやすかったことが解明された。また、
爆裂は成形体のサイズにも影響されることが判明した。
円筒か粒状の成形体でも、条件よっては、３０ｍｍ以上
の成形体は水分２６質量％以下でも１１７０℃の炉内で
爆裂が起ることがある。そこで、成形体の厚みまたは径
が３０ｍｍ以下とすることが望ましい。The reason why it was difficult to explode the molded product produced by the hole-type pelletizer and the briquette molding machine was also elucidated. In the molded body of the hole-type pelletizer, the surface on the circumferential side is dense, but the cut surface of the cylinder is loose. As a result, it was clarified that even when the water content was high, the explosion was difficult to occur because the resistance to the passage of water vapor was small. Depending on the conditions, the molded product using the hole-type pelleter has a water content of 26%.
Even in mass%, it may not explode in a furnace at 1170 ° C,
It had the best explosion resistance. In the briquette molding machine as well, since the compression was one-dimensional in the thickness direction, it was clarified that the density on the side of the briquette molded body did not increase and water vapor was easily released therefrom. Also,
Explosion was found to be affected by the size of the compact.
Even in the case of a cylindrical or granular compact, a compact having a size of 30 mm or more may explode in a furnace at 1170 ° C. even if the moisture content is 26% by mass or less, depending on conditions. Therefore, it is desirable that the thickness or diameter of the molded body be 30 mm or less.
【００３６】回転炉床式の還元炉では、中央を欠いた円
盤状の炉床が回転する。当該炉床は、焼成・還元ゾーン
を経由して、成形体の排出ゾーンで、還元済みの成形体
が排出される。その後、炉床が成形体の供給部に到達す
る。この時の炉床の温度は、１１５０〜１３００℃であ
ることから、通常の操業では、成形体供給部の温度は、
１０００〜１２５０℃である。つまり、操業条件によっ
ては、成形体供給部の温度は、１１７０℃以上のことも
ある。このような場合は、成形体供給部を冷却して、温
度を１１７０℃以下とする。冷却方法としては、成形体
供給部の周囲の天井を水冷壁としたり、成形体供給部に
高温の燃焼ガスが入らない構造にしたりする。In a rotary hearth-type reduction furnace, a disk-shaped hearth lacking a center rotates. The hearth passes through the firing / reduction zone, and the reduced compact is discharged in the discharge zone of the compact. Then, the hearth reaches the supply part of the compact. Since the temperature of the hearth at this time is 1150 to 1300 ° C., in a normal operation, the temperature of the compact supply unit is:
1000-1250 ° C. That is, depending on the operating conditions, the temperature of the compact supply unit may be 1170 ° C. or higher. In such a case, the temperature of the molded body supply unit is cooled to 1170 ° C. or lower. As a cooling method, a ceiling around the molded body supply section is formed as a water-cooled wall, or a structure in which high-temperature combustion gas does not enter the molded body supply section is used.
【００３７】次に、重要な成形体の性状は落下強度が強
いことである。成形体は、成形機から炉床まで搬送され
る過程で、コンベアの乗り継ぎと炉内への投入で、０.
５〜２ｍ程度の落下距離を数回落下する。したがって、
落下強度（形状が破壊されるまでの合計の落下距離で表
示）の強い成形体が求められ、回転炉床式還元炉では、
４〜５ｍ程度以上の値が求められている。一般的に、粉
体充填密度が低い成形体は落下強度が低いため、前述の
爆裂を起こさない条件と矛盾する。そこで、本発明者ら
は、粉体充填密度が低い成形体の落下強度を高める研究
を行った結果、水分がある比率以上あれば、落下時に成
形体が衝撃を受けても変形するだけで、破壊されないこ
とを解明した。Another important property of the molded article is that the drop strength is high. In the process of transferring the molded body from the molding machine to the hearth, the transfer of the conveyor and the introduction of the molded body into the furnace make the molded body 0.1 mm.
Drop several times over a drop distance of about 5 to 2 m. Therefore,
A molded body with a high drop strength (indicated by the total drop distance until the shape is destroyed) is required.
A value of about 4 to 5 m or more is required. In general, a compact having a low powder filling density has a low drop strength, which is inconsistent with the above-described conditions that do not cause explosion. Therefore, the present inventors have conducted a study to increase the drop strength of a compact having a low powder filling density. Clarified that it will not be destroyed.
【００３８】本発明者らは、水分の落下強度に対する影
響を研究したところ、水分が１６質量％以上であれば、
粉体充填率が０. ４３以上の成形体は、落下強度が４.
２ｍ以上あることを解明した。ただし、粉体充填率が
０. ４３以下の場合は、水分含有率に関わらず、落下強
度が２〜４ｍ程度と低かった。したがって、落下強度の
確保の観点から、水分は１６質量％以上で、粉体充填率
は０. ４３以上であることが望ましい。The present inventors have studied the effect of water on the drop strength, and found that if the water content is 16% by mass or more,
The compact having a powder filling rate of 0.43 or more has a drop strength of 4.43.
It was clarified that there was more than 2m. However, when the powder filling rate was 0.43 or less, the drop strength was as low as about 2 to 4 m regardless of the moisture content. Therefore, from the viewpoint of ensuring the drop strength, it is preferable that the water content is 16% by mass or more and the powder filling rate is 0.43 or more.
【００３９】また、水分や粉体充填密度が同じ条件で
も、前出のタイル状の成形体では０.５ｍの落下試験を
１回しただけで破壊してしまった。つまり、特開平１１
−１２６２４号公報に記載される方法でのタイル状の成
形体では、形状的に落下強度が低すぎて、通常のハンド
リング方法では、成形体のままで炉内に供給できないこ
とが判明した。それに対して、本発明の方法により製造
した成形体は、通常のハンドリング方法でも、そのまま
の形状で炉内に供給できた。Further, even under the same conditions of moisture and powder filling density, the above-mentioned tile-shaped molded product was broken only by a single drop test of 0.5 m. In other words,
It has been found that a tile-shaped molded product obtained by the method described in JP-A-12624 is too low in shape in terms of shape, and cannot be supplied into a furnace as it is by a normal handling method. On the other hand, the molded article manufactured by the method of the present invention could be supplied into the furnace in the same shape by the usual handling method.
【００４０】以上の実験結果をもとに、本発明者らは、
成形体の条件として、水分が１６〜２６質量％の範囲
で、粉体充填率が０. ４３〜０. ５８の範囲にすること
のぞましく、前出の穴型ペレッターとブリッケト成形機
が最も有効な装置であることを解明した。他の装置でも
本発明の目的にかなう成形体を製造することは可能であ
るが、穴型ペレッターとブリッケト成形機は、成形体の
性能も良く、製造コストも低いため、最も有効な装置で
ある。Based on the above experimental results, the present inventors
As the conditions of the molded body, it is preferable that the water content is in the range of 16 to 26% by mass and the powder filling rate is in the range of 0.43 to 0.58. It was found that this was the most effective device. Although it is possible to produce a molded article that meets the object of the present invention with other apparatuses, the hole-type pelletizer and the briquette molding machine are the most effective apparatuses because the molded article has good performance and the production cost is low. .
【００４１】以上の方法により成形された成形体は、湿
状態のまま、成形体搬送コンベア７を経由して、成形体
の供給装置である、首振りコンベア８を用いて、回転炉
床式還元炉９に供給される。回転炉床式還元炉９の成形
体供給部の温度は１１７０℃以下とする。The compact formed by the above-mentioned method is kept in a wet state via a compact transfer conveyor 7 and a swing hearth conveyor 8, which is a supply unit for the compact, using a rotary hearth type reduction. It is supplied to a furnace 9. The temperature of the compact supply part of the rotary hearth reduction furnace 9 is set to 1170 ° C. or less.
【００４２】回転炉床式還元炉９では、湿状態の成形体
は、１１７０℃以下の雰囲気温度である部分に供給され
る。雰囲気温度が１１７０℃の場合は、成形体内部の温
度上昇率が高すぎて、水蒸気圧力が高くなり、本発明の
範囲の条件で製造した成形体でも爆裂を起こす可能性が
高いため、この部分の温度は１１７０℃以下とする必要
がある。In the rotary hearth reduction furnace 9, the wet compact is supplied to a portion having an atmospheric temperature of 1170 ° C. or less. When the ambient temperature is 1170 ° C., the temperature rise rate inside the molded article is too high, the steam pressure becomes high, and the molded article produced under the conditions of the present invention has a high possibility of causing explosion. Must be 1170 ° C. or lower.
【００４３】回転炉床式還元炉９では、成形体が１１０
０〜１３００℃程度の温度で焼成され、成形体内部の炭
素分により、酸化金属が還元される。本発明の原料混合
方法は、水を多く含む状態で撹拌混合されているため、
成形体の酸化金属と炭素が均一に混合されており、効率
よく反応する効果もある。In the rotary hearth type reduction furnace 9, the compact is 110
It is fired at a temperature of about 0 to 1300 ° C., and the metal oxide is reduced by the carbon content inside the molded body. Since the raw material mixing method of the present invention is stirred and mixed in a state containing a large amount of water,
Since the metal oxide and carbon of the molded body are uniformly mixed, there is also an effect of efficiently reacting.
【００４４】さらに、本発明者らは、酸化鉄の還元の際
には、炭素比率のコントロールが重要であることを解明
した。酸化鉄の還元の際には、炭素が不足すると、還元
が不完全で金属化率が低くなることがあり、また、炭素
が大過剰であると、余剰の炭素が鉄と反応して、セメン
タイト（Fe３C）を生成して、還元された成形体が１２
００℃前後で炉内で溶融を始める。一般的な回転炉床式
還元炉は、溶融鉄を扱うように炉床や排出装置が設計さ
れていないため、溶融鉄ができると炉床が損傷する問題
が発生する。Further, the present inventors have clarified that the control of the carbon ratio is important in the reduction of iron oxide. In the reduction of iron oxide, if the carbon is insufficient, the reduction may be incomplete and the metallization rate may be low, and if the carbon is excessively large, the excess carbon reacts with the iron to form cementite. (Fe3C) is produced and the reduced compact is 12
At around 00 ° C, melting starts in the furnace. In a general rotary hearth-type reduction furnace, since the hearth and the discharge device are not designed to handle molten iron, there is a problem that the hearth is damaged if molten iron is formed.
【００４５】成形体に含有する固定炭素が、酸化鉄と化
合している酸素に対して一酸化炭素まで反応すると仮定
して計算された固定炭素のモル数（以降、計算炭素モル
量と称す）の１. ５倍以下の範囲の量であれば、上記さ
れた還元不足と鉄溶融の問題が発生しない。また、本発
明者らは、条件で変わることがあるが、酸化鉄と反応す
る炭素は、一酸化炭素までの反応と二酸化炭素までの反
応の中間で、１０％から７０％が二酸化炭素までの反応
であることが解明した。その結果、計算炭素モル量の
０．５倍以上の固定炭素量であれば、金属化率が７０％
以上の還元生成物が得られる。The number of moles of fixed carbon calculated on the assumption that the fixed carbon contained in the compact reacts with the oxygen combined with iron oxide to carbon monoxide (hereinafter referred to as calculated carbon mole amount) If the amount is 1.5 times or less of the above range, the above-mentioned problems of insufficient reduction and iron melting do not occur. In addition, the present inventors may change the conditions, but carbon that reacts with iron oxide is between 10% and 70% of carbon dioxide between carbon monoxide and carbon dioxide. It turned out to be a reaction. As a result, if the fixed carbon amount is 0.5 times or more the calculated carbon molar amount, the metallization ratio is 70%.
The above reduction product is obtained.
【００４６】計算炭素量に対して固定炭素量が０. ５の
場合は、鉄の金属化率は８０％程度で、何とか直接還元
鉄として使用できるものである。一方、計算炭素量に対
して固定炭素量が１. ５の場合は、金属化率は、９７％
と非常に高いものである。その時の還元物の金属鉄量に
対して、残留炭素量は２. ５％程度であった。その結
果、残留炭素の全量が鉄に浸炭していても、融点が１３
００℃以上であり、最高でも１３００℃程度の回転炉床
式還元炉内の温度では、還元物溶融の問題は起きない。When the fixed carbon amount is 0.5 with respect to the calculated carbon amount, the metallization ratio of iron is about 80%, and somehow it can be directly used as reduced iron. On the other hand, when the fixed carbon amount is 1.5 with respect to the calculated carbon amount, the metallization ratio is 97%.
And very expensive. At that time, the amount of residual carbon was about 2.5% based on the amount of metallic iron as the reduced product. As a result, even if the entire amount of residual carbon is carburized into iron, the melting point is 13
At a temperature in the rotary hearth-type reduction furnace of not less than 00 ° C. and at most about 1300 ° C., the problem of melting the reduced product does not occur.
【００４７】還元された成形体は、回転炉床式還元炉９
から排出されて、製品冷却装置１３にて、常温まで冷却
される。ただし、電気炉等で使用する場合には、９００
℃程度の高温のまま溶解工程に供給することもある。回
転炉床式還元炉９からの燃焼排ガスはガス冷却装置１０
と集塵機１１を経由して、煙突１２から大気に放散され
る。The reduced compact is supplied to a rotary hearth reducing furnace 9
And cooled by the product cooling device 13 to room temperature. However, when used in an electric furnace, etc., 900
It may be supplied to the melting step at a high temperature of about ° C. The combustion exhaust gas from the rotary hearth reduction furnace 9 is supplied to a gas cooling device 10.
Through the dust collector 11, and is emitted to the atmosphere from the chimney 12.
【００４８】なお、回転炉床式還元炉で使用する原料成
形体については、含有水分が１６〜２６質量％の範囲、
かつ、粉体充填率が０. ４３〜０. ５８の範囲、かつ、
厚みまたは径が３０ｍｍ以下である、酸化金属を含む粉
体と炭素を含む粉体の混合物を圧縮成形して製造した円
筒または粒状の成形体であることを満たしていれば、必
ずしも、上記の手順をふまえた方法で製造したものでな
くとも、本発明の目的にかなった還元操業が可能であ
る。The raw material compact used in the rotary hearth reduction furnace has a water content of 16 to 26% by mass.
And the powder filling rate is in the range of 0.43 to 0.58, and
If the thickness or the diameter is not more than 30 mm, and if it satisfies that it is a cylindrical or granular compact produced by compression-molding a mixture of powder containing metal oxide and powder containing carbon, the above procedure is not necessarily required. The reduction operation for the purpose of the present invention is possible even if it is not manufactured by a method based on the above.
【００４９】本発明を金属の精錬もしくは加工で発生す
るスラジやダストの処理に活用することは、特に、有効
な方法である。例えば、製鉄所の高炉のガス灰は湿式の
ベンチュリースクラバーで集塵して、シックナーでスラ
リーなっている。また、圧延の酸洗での廃酸を中和した
中和スラジもある。このようなダストやスラジは脱水機
をかけて処理しているが、再利用することが難しく、費
用もかかるものである。これらのダストやスラジをシッ
クナーから混合槽１に直接受ければ、中間処理がなく、
簡単な方法で還元処理用の原料成形体とすることができ
る。したがって、金属の精錬また加工の工程で発生する
ダストやスラジを用いることは、本発明にとって最も望
ましい方法の一つである。It is a particularly effective method to utilize the present invention for treating sludge and dust generated during refining or processing of metal. For example, gas ash from a blast furnace at a steel mill is collected by a wet-type venturi scrubber, and is slurried with a thickener. There is also a neutralized sludge in which the waste acid from the pickling of rolling is neutralized. Although such dust and sludge are treated by a dehydrator, they are difficult and expensive to reuse. If these dust and sludge are received directly from the thickener into the mixing tank 1, there is no intermediate treatment,
A raw material compact for reduction treatment can be obtained by a simple method. Therefore, the use of dust and sludge generated during metal refining and processing is one of the most desirable methods for the present invention.
【００５０】ここで、操業方法の比較として、従来法に
よる操業の設備を図２に示す。従来法の設備での操業で
は、本発明の設備の操業の脱水工程の後に、原料はスラ
ジ粉体搬送コンベア１５で送られ、粉体乾燥機１６で水
分が５〜１０質量％の範囲の乾燥する。また、その後、
粉体に散水装置１８で加水しながら、造粒装置１７にて
ペレットを製造する。さらに、ペレット搬送コンベア１
９にて、ペレット乾燥装置２０に送られて、ここでペレ
ットを水分２質量％程度まで乾燥する。その後に、回転
炉床式還元炉にて、ペレットを焼成還元する。このよう
に、本発明による方法に比べると、従来法による操業は
多工程にわたり、複雑である。また、連続して、脱水、
乾燥、加水、脱水と水分調整を繰り返すことから、この
ためのエネルギーロスも大きい方法である。Here, as a comparison of operation methods, FIG. 2 shows equipment for operation according to the conventional method. In the operation of the conventional equipment, after the dewatering step of the operation of the equipment of the present invention, the raw material is sent by the sludge powder conveyor 15 and dried by the powder dryer 16 in the range of 5 to 10% by mass of water. I do. And then,
Pellet is produced by the granulator 17 while adding water to the powder by the sprinkler 18. Furthermore, the pellet transport conveyor 1
At 9, the pellets are sent to a pellet drying device 20, where the pellets are dried to about 2% by weight of water. Thereafter, the pellets are fired and reduced in a rotary hearth reduction furnace. Thus, compared to the method according to the invention, the operation according to the conventional method is multi-step and complicated. Also, continuously, dehydration,
Since drying, water addition, dehydration and moisture adjustment are repeated, the energy loss for this is also a large method.
【００５１】回転炉床式還元炉で使用する原料としての
観点からは、本発明は湿状態の原料から製造する際に、
還元用成形体は最も簡易に製造できる技術である。圧縮
成形機で製造された成形体の条件は、円筒もしくは粒状
で、厚みもしくは径が３０ｍｍ以下であり、含有水分が
１６〜２６質量％の範囲、かつ、粉体充填率が０. ４３
〜０. ５８の範囲であることが発明の範囲である。上記
の方法で成形された成形体を還元すると、原料成形体の
落下強度が高く、また、爆裂もしないため、回転炉床式
還元炉で経済的に還元ができる原料成形体である。From the viewpoint of a raw material used in a rotary hearth-type reduction furnace, the present invention relates to a method for producing from a raw material in a wet state.
The reduction molding is the technology that can be most easily manufactured. The conditions of the compact produced by the compression molding machine are cylindrical or granular, have a thickness or diameter of 30 mm or less, a water content in the range of 16 to 26% by mass, and a powder filling rate of 0.43.
It is within the scope of the present invention to fall within the range of 0.58. When the compact formed by the above method is reduced, the raw compact has a high drop strength and does not explode, so that it can be economically reduced in a rotary hearth type reduction furnace.
【００５２】[0052]
【実施例】本発明に基づく操業を行った実施例を表１に
示す。使用した設備は、図１に示される構成のものであ
り、還元能力は、湿状態の成形体量の基準で、毎時１０
トンのものである。脱水機は双ロール式のもの、成形機
は穴型ペレッターを用いた。EXAMPLES Examples in which the operation according to the present invention was performed are shown in Table 1. The equipment used had the configuration shown in FIG. 1 and the reduction capacity was 10 hours / hour based on the amount of the molded body in a wet state.
Tons of things. The dewatering machine used was a twin-roll type, and the molding machine used was a hole-type pelleter.
【００５３】[0053]
【表１】 原料は、表１に示すとおり、微粉の粉鉱石であるペレッ
トフィードと１ｍｍアンダーのコークス粉の混合物と、
一貫製鉄所での高炉ガス灰、熱間圧延スケールピットの
沈殿スラジ、および、１ｍｍアンダーのコークス粉の混
合物の２種類を用いた。[Table 1] The raw materials are, as shown in Table 1, a mixture of pellet feed, which is fine ore fine powder, and 1 mm under coke powder,
Two types were used: a blast furnace gas ash at an integrated steel mill, sedimentation sludge of hot-rolled scale pits, and a mixture of 1 mm under coke powder.
【００５４】操業条件としては、表１に示すとおりであ
るが、混合槽１の原料水分は粉体質量の１２０〜２００
％、成形前の原料水分は粉体質量の１７〜２０％であ
る。粉体充填率は、本発明の範囲内である。また、成形
体のサイズは、直径が１５ｍｍで長さが２５ｍｍであ
る。成形体の投入部の炉内温度は、約９８０℃、還元部
の炉内温度は１２１０℃であり、また、還元時間は１５
分である。The operating conditions are as shown in Table 1. The water content of the raw material in the mixing tank 1 is 120 to 200% of the powder mass.
%, And the raw material moisture content before molding is 17 to 20% of the powder mass. The powder loading is within the scope of the present invention. The size of the molded body is 15 mm in diameter and 25 mm in length. The furnace temperature at the injection section of the molded body was about 980 ° C., the furnace temperature at the reduction section was 1210 ° C., and the reduction time was 15 minutes.
Minutes.
【００５５】実施例１は、ペレットフィードを用いた操
業例で、炭素混合比率の適正であったことから、生産性
の高い操業であった。この操業では、金属化率は９７％
と高く、落下による粉化と爆裂がほとんどなかったこと
から、塊製品歩留も９４％と高かった。実施例２は、高
炉ガス灰と熱間圧延スケールピットの沈殿スラジを用い
た操業例で、還元とともに脱亜鉛と脱アルカリも狙った
操業である。この操業では、金属化率は９１％で、脱Zn
率は９７. ５％、脱アルカリ率は９９％と不純物除去は
有効にできていた。この実施例でも落下による粉化と爆
裂がほとんどなかったことから、塊製品歩留も９５％と
高かった。Example 1 was an operation example using a pellet feed, and was an operation with high productivity because the carbon mixing ratio was appropriate. In this operation, the metallization rate is 97%
Since there was almost no powdering and explosion due to falling, the lump product yield was as high as 94%. Example 2 is an example of operation using blast furnace gas ash and sedimentation sludge of hot-rolled scale pits, and is an operation aiming at dezincification and dealkalization as well as reduction. In this operation, the metallization rate is 91%,
The rate was 97.5% and the dealkalization rate was 99%, indicating that the removal of impurities was effective. Also in this example, since there was almost no powdering and explosion due to falling, the lump product yield was as high as 95%.
【００５６】本発明による還元操業と図２に示される設
備を使用した従来法との経済性を比較した。本発明での
操業では、原料の前処理が混合工程、脱水工程、およ
び、成形工程しかないため、原料前処理の費用は、比較
例に比べて、３０％程度で済んでいる。また、プロセス
全体での費用でも、約１５％の削減ができた。The economics of the reduction operation according to the present invention and the conventional method using the equipment shown in FIG. 2 were compared. In the operation according to the present invention, since the pretreatment of the raw material includes only the mixing step, the dehydration step, and the molding step, the cost of the raw material pretreatment is about 30% as compared with the comparative example. In addition, the cost of the entire process was reduced by about 15%.
【００５７】以上のように、湿状態の粉体を使用する本
発明を用いた操業では、原料成形体の爆裂などの操業上
の問題もなく、安価な建設費用で、エネルギー消費量を
はじめとする操業費用も安価である。その結果、回転炉
床式還元炉での鉱石、および、酸化金属含有のダストや
スラジの粉体の還元を経済的に実施できた。As described above, in the operation using the present invention using the powder in the wet state, there is no operational problem such as explosion of the raw material molded body, the construction cost is low, the energy consumption and the like are low. The operating costs are low. As a result, it was possible to economically reduce ore and dust or sludge powder containing metal oxide in the rotary hearth reduction furnace.
【００５８】[0058]
【発明の効果】本発明によれば、還元用回転炉床法にお
いて、経済的に、湿状態の粉体原料を用いて、酸化金属
の還元を行い、金属の製造することができる。また、金
属製造業から発生する酸化金属を含むダストとスラジの
処理を経済的に実施することには有効な手段である。特
に、水分を大量に含有するダストとスラジを処理するた
めに、本発明による操業は有効な手段である。According to the present invention, in the rotary hearth method for reduction, a metal oxide can be economically reduced by using a wet powder material to produce a metal. It is also an effective means for economically treating dust and sludge containing metal oxides generated from the metal manufacturing industry. In particular, the operation according to the present invention is an effective means for treating dust and sludge containing a large amount of water.
【図１】本発明に基づく、水分を含む粉体原料を還元す
る回転炉床式還元炉の設備構成の一例を示す図である。FIG. 1 is a diagram showing an example of an equipment configuration of a rotary hearth-type reduction furnace for reducing a powder material containing water according to the present invention.
【図２】従来法に基づく、回転炉床式還元炉設備構成の
一例を示す図である。FIG. 2 is a diagram showing an example of a rotary hearth type reduction furnace equipment configuration based on a conventional method.
【図３】エンドレスの帯状のフィルターの上にスラリー
を落とし、圧縮双ロールにて、圧搾する形式の脱水装置
を示す図である。FIG. 3 is a diagram showing a dewatering apparatus of a type in which a slurry is dropped on an endless belt-shaped filter and pressed by a compression twin roll.
【図４】粉体を穴型から押し出し形式の圧縮成形機を示
す図である。左が構成図で、右が圧縮ローラーの図であ
る。FIG. 4 is a view showing a compression molding machine of a type in which powder is extruded from a hole die. The left is a configuration diagram, and the right is a diagram of a compression roller.
【図５】凹状の型で粉体を圧縮成形する形式のブリッケ
ト圧縮成形機を示す図である。FIG. 5 is a view showing a briquette compression molding machine of a type in which powder is compression-molded in a concave mold.
【図６】成形体の粉体充填率が１１７０℃での爆裂限界
水分に与える影響を示す図である。FIG. 6 is a graph showing the effect of the powder filling rate of a compact on the explosion limit moisture at 1170 ° C.
１ 混合槽 ２ 撹拌装置 ３ スラリーポンプ ４ 脱水装置 ５ スラジ搬送コンベア ６ 圧縮成形機 ７ 成形体搬送コンベア ８ 首振りコンベア ９ 回転炉床式還元炉 １０ ガス冷却装置 １１ 集塵機 １２ 煙突 １３ 製品冷却装置 １４ 脱水装置 １５ スラジ粉体搬送コンベア １６ 粉体乾燥機 １７ 造粒機 １８ 散水装置 １９ ペレット搬送コンベア ２０ ペレット乾燥装置 ２１ 乾燥ペレットコンベア ２２ スラリー入口 ２３ フィルター ２４ 真空吸引装置 ２５ 圧縮双ロール ２６ スラリー ２７ 脱水物 ２８ 原料供給口 ２９ 駆動装置 ３０ 駆動動力伝達機構 ３１ 駆動シャフト ３２ ローラー ３３ 底プレート ３４ 穴型 ３５ 成形体 ３６ 原料供給部 ３７ 圧縮ローラー ３８ 凹状くぼみ ３９ ブリッケト DESCRIPTION OF SYMBOLS 1 Mixing tank 2 Stirrer 3 Slurry pump 4 Dehydrator 5 Sludge transport conveyor 6 Compression molding machine 7 Conveyor for molding 8 Swing conveyor 9 Rotary hearth type reduction furnace 10 Gas cooling device 11 Dust collector 12 Chimney 13 Product cooling device 14 Dehydration Apparatus 15 Sludge powder transport conveyor 16 Powder dryer 17 Granulator 18 Sprinkler 19 Pellet transport conveyor 20 Pellet dryer 21 Dry pellet conveyor 22 Slurry inlet 23 Filter 24 Vacuum suction device 25 Compression twin roll 26 Slurry 27 Dehydrated material 28 Raw material supply port 29 Drive device 30 Drive power transmission mechanism 31 Drive shaft 32 Roller 33 Bottom plate 34 Hole type 35 Molded body 36 Raw material supply section 37 Compression roller 38 Concave recess 39 Briquette
フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｃ２２Ｂ 1/24 Ｃ２２Ｂ 1/24 (72)発明者 近藤 敏 君津市君津１番地 新日本製鐵株式会社君 津製鐵所内 (72)発明者 井村 章次 君津市君津１番地 新日本製鐵株式会社君 津製鐵所内 (72)発明者 安部 洋一 富津市新富20−１ 新日本製鐵株式会社技 術開発本部内Continuation of the front page (51) Int.Cl. 7 Identification symbol FI Theme coat II (reference) C22B 1/24 C22B 1/24 (72) Inventor Satoshi Kondo 1 Kimitsu, Kimitsu-shi Nippon Steel Corporation Kimitsu Steel Corporation In-house (72) Inventor Shoji Imura 1 Kimitsu, Kimitsu-shi Nippon Steel Corporation Kimitsu Works (72) Inventor Yoichi Abe 20-1 Shintomi, Futtsu-shi Nippon Steel Corporation Technology Development Division
Claims (14)
物を、水分量を混合物全体の１５〜３０質量％になるよ
うに脱水し、該混合物を圧縮成形により複数の円柱又は
粒状の成形体とした後、直接、還元炉内に投入して焼成
還元することを特徴とする回転炉床式還元炉の操業方
法。1. A mixture of a powder containing metal oxide, carbon and water is dehydrated so that the water content is 15 to 30% by mass of the whole mixture, and the mixture is subjected to compression molding to form a plurality of cylinders or granules. A method for operating a rotary hearth-type reduction furnace, wherein the raw material is directly put into a reduction furnace and calcined and reduced.
上含む状態で、酸化金属と炭素を含む粉体を撹拌混合し
て、これを１６〜２６質量％の含有水分まで脱水装置で
脱水した後に、圧縮成形機で成形して製造した、粉体充
填率が０. ４３〜０. ５８の範囲である成形体を、雰囲
気温度が１１７０℃以下である炉内部分に投入して、そ
の後に１２００℃以上の温度で焼成還元することを特徴
とする回転炉床式還元炉の操業方法。2. A dehydration apparatus in which a powder containing a metal oxide and carbon is stirred and mixed in a state where water is contained at least 1.0 times the total weight of the powder, and this is dehydrated to a water content of 16 to 26% by mass. After the dehydration, a molded body having a powder filling ratio in the range of 0.43 to 0.58, produced by molding with a compression molding machine, is charged into a furnace portion having an atmosphere temperature of 1170 ° C. or lower. And then reducing by firing at a temperature of 1200 ° C. or higher.
を受ける帯状のフィルター、および、当該フィルターを
上下から挟み込んで圧縮する双ロールを有する脱水機を
用いることを特徴とする請求項１又は２記載の回転炉床
式還元炉の操業方法。3. A dewatering device comprising: a band-shaped filter for receiving powder containing water; and a dehydrator having twin rolls for sandwiching and compressing the filter from above and below. 2. The method for operating a rotary hearth-type reduction furnace according to 2.
くなるテーパーを有する円筒形状である、水分を含む状
態の粉体の保持部とその内部にスクリュー式の粉体排出
機構を有し、当該保持部と当該粉体排出機構の差速が毎
分２〜３０回転であり、当該保持部に働く遠心力が５０
０Ｇ以上の遠心式脱水機を用いることを特徴とする請求
項１又は２記載の回転炉床式還元炉の操業方法。4. A dewatering device, comprising a vertical cylindrical holding member having a tapered shape tapering inward at a lower portion and having a water-containing state, and a screw-type powder discharging mechanism provided therein. The differential speed between the holding unit and the powder discharging mechanism is 2 to 30 rotations per minute, and the centrifugal force acting on the holding unit is 50
The method for operating a rotary hearth type reduction furnace according to claim 1 or 2, wherein a centrifugal dehydrator of 0 G or more is used.
するフィルターを両側から１０6N/m2以上の力で押しつ
ける装置を有する脱水装置を用いて脱水することを特徴
とする請求項１又は２記載の回転炉床式還元炉の操業方
法。5. The dewatering device according to claim 1, wherein the dewatering device has a device for pressing a filter holding a powder containing water from both sides with a force of 10 6 N / m 2 or more. Or the operation method of the rotary hearth reduction furnace according to 2.
つ、厚みまたは径が３０ｍｍ以下である、酸化金属を含
む粉体と炭素を含む粉体の混合物を圧縮成形して製造し
た、粉体充填率が０. ４３〜０. ５８の範囲である円柱
または粒状の成形体を、雰囲気温度が１１７０℃以下で
ある炉内部分に投入して、その後に１２００℃以上の温
度で焼成還元することを特徴とする回転炉床式還元炉の
操業方法。6. A powder produced by compression molding a mixture of a powder containing metal oxide and a powder containing carbon having a water content in the range of 16 to 26% by mass and a thickness or diameter of 30 mm or less. A cylindrical or granular compact having a body filling rate in the range of 0.43 to 0.58 is charged into a furnace portion having an atmosphere temperature of 1170 ° C. or lower, and then calcined and reduced at a temperature of 1200 ° C. or higher. A method for operating a rotary hearth-type reduction furnace, comprising:
込む装置と湿状態の粉体が通過する穴型からなる押し出
し穴型式の圧縮成形機を用いる請求項１又は６記載の回
転炉床式還元炉の操業方法。7. The rotary hearth according to claim 1, wherein a compression molding machine of an extrusion hole type comprising a device for injecting powder in a wet state and a hole through which the powder in a wet state passes is used as the compression molding machine. Operating method of the type reduction furnace.
の型に湿状態の粉体を押しつけて成形するブリッケト成
形機を用いることを特徴とする請求項１又は２に又は６
記載の回転炉床式還元炉の操業方法。8. A compression molding machine using a briquette molding machine which presses and forms a wet powder against a concave mold on the surface of a twin roll.
The method for operating the rotary hearth-type reduction furnace described in the above.
金属を含む粉体と炭素を含む粉体の混合物を圧縮成形し
て製造した円柱または粒状の成形体を還元することを特
徴とする請求項６記載の回転炉床式還元炉の操業方法。9. A cylindrical or granular compact produced by compression-molding a mixture of a powder containing metal oxide having a thickness or a diameter of 30 mm or less and a powder containing carbon is reduced. 7. The method for operating a rotary hearth reduction furnace according to 6.
有粉体を用いる場合に、酸化鉄と化合している酸素の原
子モル量に対して固定炭素の原子モル量が０. ５〜１.
５倍の範囲の成形体を還元することを特徴とする請求項
１又は６記載の回転炉床式還元炉の操業方法。10. When an iron oxide-containing powder is used as the powder containing a metal oxide, the atomic molar amount of fixed carbon is 0.5 to 1 relative to the atomic molar amount of oxygen combined with iron oxide. .
The method for operating a rotary hearth-type reduction furnace according to claim 1 or 6, wherein the compact is reduced by a factor of five.
もしくは粒状の成形体を、他の炉内部分よりも雰囲気温
度を低下させている部分に投入して、焼成還元すること
を特徴とする請求項１又は６記載の回転炉床式還元炉の
操業方法。11. A cylindrical or granular molded product produced by molding with a compression molding machine is charged into a portion where the ambient temperature is lower than that in another furnace portion, and calcined and reduced. The method for operating a rotary hearth reduction furnace according to claim 1 or 6.
合物を、水分量を混合物全体の１５〜３０質量％になる
ように脱水し、該混合物を圧縮成形により外形が３０ｍ
ｍ以下の円柱又は粒状の成形体としたことを特徴とする
還元炉原料の成形体。12. A mixture of a powder containing metal oxide, carbon and moisture is dehydrated so that the amount of moisture is 15 to 30% by mass of the whole mixture, and the mixture is compression molded to have an outer shape of 30 m.
m. A molded product of a raw material for a reduction furnace, wherein the molded product is a cylindrical or granular molded product having a particle size of m or less.
かつ、厚みまたは径が３０ｍｍ以下である、酸化金属を
含む粉体と炭素を含む粉体の混合物を圧縮成形して製造
して得た、粉体充填率が０. ４３〜０. ５８の範囲であ
る円筒または粒状であることを特徴とする還元炉原料の
成形体。13. A water content in a range of 16 to 26% by mass,
And a powder filling ratio in the range of 0.43 to 0.58, obtained by compression molding a mixture of powder containing metal oxide and powder containing carbon and having a thickness or diameter of 30 mm or less. A molded product of a raw material for a reduction furnace, wherein the molded product is a cylindrical or granular material.
有粉体を用いる場合に、酸化鉄と化合している酸素の原
子モル量に対して固定炭素の原子モル量が０. ５〜１.
５倍の範囲であることを特徴とする請求項１２又は１３
記載の還元炉原料の成形体。14. When an iron oxide-containing powder is used as the powder containing a metal oxide, the atomic molar amount of fixed carbon is 0.5 to 1 relative to the atomic molar amount of oxygen combined with iron oxide. .
14. A range that is five times as large as that of the first embodiment.
A molded article of the raw material of the reduction furnace according to the above.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000372019A JP3779873B2 (en) | 1999-12-16 | 2000-12-06 | Operation method of rotary hearth reduction furnace |
| AU17368/01A AU1736801A (en) | 1999-12-13 | 2000-12-12 | Facilities for reducing metal oxide, method for operating the facilities and moldings as law material to be charged to reduction furnace |
| CNB008058164A CN1262676C (en) | 1999-12-13 | 2000-12-12 | Facilities for reducing metal oxide, method for operating the facilities and moldings as raw material to be charged to reduction furnace |
| EP20000980059 EP1170384B1 (en) | 1999-12-13 | 2000-12-12 | A method of operating a rotary hearth reducing furnace |
| PCT/JP2000/008771 WO2001042516A1 (en) | 1999-12-13 | 2000-12-12 | Facilities for reducing metal oxide, method for operating the facilities and moldings as law material to be charged to reduction furnace |
| TW89126496A TW527423B (en) | 1999-12-13 | 2000-12-12 | Facilities for reducing metal oxide, method for operating the facilities and moldings as raw material to be charged to reduction furnace |
| US09/913,287 US6755888B2 (en) | 1999-12-13 | 2000-12-12 | Facility for reducing metal oxide, method for operating the facilities and moldings as raw material to be charged to reduction furnace |
| KR1020017010263A KR100673785B1 (en) | 1999-12-13 | 2000-12-12 | Facilities for reducing metal oxide, method for operating the facilities and moldings as law material to be charged to reduction furnace |
| US10/834,870 US7192552B2 (en) | 1999-12-13 | 2004-04-30 | Facility for reducing metal oxide, method of operating the same, and shaped article of raw material for reducing furnace |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
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| JP35701299 | 1999-12-16 | ||
| JP11-357012 | 1999-12-16 | ||
| JP2000372019A JP3779873B2 (en) | 1999-12-16 | 2000-12-06 | Operation method of rotary hearth reduction furnace |
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| JP2001234256A true JP2001234256A (en) | 2001-08-28 |
| JP3779873B2 JP3779873B2 (en) | 2006-05-31 |
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| JP2000372019A Expired - Fee Related JP3779873B2 (en) | 1999-12-13 | 2000-12-06 | Operation method of rotary hearth reduction furnace |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002097142A1 (en) * | 2001-05-30 | 2002-12-05 | Nippon Steel Corporation | Device and method for treating oil-adhered particles |
| JP2003082419A (en) * | 2001-09-14 | 2003-03-19 | Nippon Steel Corp | Molding method for powder, and molding apparatus for powder |
| EP1426451A1 (en) * | 2001-09-14 | 2004-06-09 | Nippon Steel Corporation | METHOD FOR PRODUCING REDUCED IRON COMPACT IN ROTARY HEARTH REDUCING FURNACE, REDUCED IRON COMPACT, AND METHOD FOR PRODUCING PIG IRON USING THE SAME |
| JP2005179771A (en) * | 2003-11-28 | 2005-07-07 | Jfe Steel Kk | Method for agglomerating iron-making sludge |
| WO2009051172A1 (en) * | 2007-10-19 | 2009-04-23 | Nippon Steel Corporation | Process for producing pre-reduced iron |
| CN112280975A (en) * | 2020-11-04 | 2021-01-29 | 韶关市曲江盛大冶金渣环保科技开发有限公司 | Method and device for pressing powder balls under screen of rotary hearth furnace |
-
2000
- 2000-12-06 JP JP2000372019A patent/JP3779873B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002097142A1 (en) * | 2001-05-30 | 2002-12-05 | Nippon Steel Corporation | Device and method for treating oil-adhered particles |
| JP2003082419A (en) * | 2001-09-14 | 2003-03-19 | Nippon Steel Corp | Molding method for powder, and molding apparatus for powder |
| EP1426451A1 (en) * | 2001-09-14 | 2004-06-09 | Nippon Steel Corporation | METHOD FOR PRODUCING REDUCED IRON COMPACT IN ROTARY HEARTH REDUCING FURNACE, REDUCED IRON COMPACT, AND METHOD FOR PRODUCING PIG IRON USING THE SAME |
| US6986801B2 (en) | 2001-09-14 | 2006-01-17 | Nippon Steel Corporation | Method of producing reduced iron compacts in rotary hearth-type reducing furnace, reduced iron compacts, and method of producing molten iron using them |
| EP1426451A4 (en) * | 2001-09-14 | 2008-07-16 | Nippon Steel Corp | Method for producing reduced iron compact in rotary hearth reducing furnace, reduced iron compact, and method for producing pig iron using the same |
| JP2005179771A (en) * | 2003-11-28 | 2005-07-07 | Jfe Steel Kk | Method for agglomerating iron-making sludge |
| WO2009051172A1 (en) * | 2007-10-19 | 2009-04-23 | Nippon Steel Corporation | Process for producing pre-reduced iron |
| US8182575B2 (en) | 2007-10-19 | 2012-05-22 | Nippon Steel Corporation | Producing method of direct reduced iron |
| CN112280975A (en) * | 2020-11-04 | 2021-01-29 | 韶关市曲江盛大冶金渣环保科技开发有限公司 | Method and device for pressing powder balls under screen of rotary hearth furnace |
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