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WO2003018849A1 - Hearth for moving floor furnace - Google Patents

Hearth for moving floor furnace Download PDF

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Publication number
WO2003018849A1
WO2003018849A1 PCT/JP2002/008754 JP0208754W WO03018849A1 WO 2003018849 A1 WO2003018849 A1 WO 2003018849A1 JP 0208754 W JP0208754 W JP 0208754W WO 03018849 A1 WO03018849 A1 WO 03018849A1
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WO
WIPO (PCT)
Prior art keywords
hearth
refractory
furnace
moving
iron oxide
Prior art date
Application number
PCT/JP2002/008754
Other languages
French (fr)
Japanese (ja)
Inventor
Hiroshi Ichikawa
Shinji Shima
Tomoaki Shibata
Original Assignee
Nippon Steel Corporation
Priority date (The priority date 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 date listed.)
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Publication date
Application filed by Nippon Steel Corporation filed Critical Nippon Steel Corporation
Publication of WO2003018849A1 publication Critical patent/WO2003018849A1/en

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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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D1/0003—Linings or walls
    • F27D1/0006—Linings or walls formed from bricks or layers with a particular composition or specific characteristics
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D1/0043—Floors, hearths
    • 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

Definitions

  • Heating iron oxide agglomerates containing carbon material on a moving bed that moves in the furnace •
  • This relates to a hearth used in a moving bed furnace that reduces and produces reduced iron agglomerates.
  • the present invention relates to a hearth used for a rotary hearth furnace for producing reduced iron.
  • US Patent No. 4,597,564 discloses dead hearth dolomite particles on the upper surface of the hearth of a rotary hearth furnace as a prior art relating to a hearth used in a moving hearth furnace for producing reduced iron agglomerates.
  • a hearth having a surface exposed to heat made of a refractory material comprising:
  • the thickness of the refractory material consisting of dead-burnt dolomite grains is 7.5 to 15 cm.
  • the particle size has a particle size of 100% minus 1 cm.
  • dead burnt dolomite grains are less expensive than magnetite grains, but they are not generated as waste, so they need to be purchased separately for moving bed furnaces and are expensive.
  • Japanese Patent No. 2997459 discloses a hearth in which a hearth material containing iron oxide as a main component (total iron content is 30% or more) is layered on a basic refractory of a moving floor.
  • a moving bed formed by sintering a hearth material in a reduction furnace is used, and the moving bed formed by sintering is in a non-molten state at the operating temperature of the reduction step.
  • the temperature rises to the operating temperature of 1250 to 1350 ° C sintering is completed and a hard porous hearth is formed.
  • an intermediate layer mainly composed of magnesium oxide is interposed between a basic refractory and the hearth material.
  • Magnesium oxide has a high melting point of 2800 ° C, and does not produce other refractories and low-melting substances near the operating temperature of 1300 ° C.
  • the intermediate layer mainly composed of magnesium oxide is preferably in the form of powder, granules, or lump obtained by crushing magnesia clinker.
  • An object of the present invention is to solve the above-mentioned problems of the prior art relating to a hearth used for a moving hearth furnace, and to provide a hearth using an inexpensive material that is excellent in heat resistance.
  • the present invention lays refractory waste including magnesium oxide on the upper surface of a hearth for a moving floor, thereby reducing the cost of purchasing hearth materials while ensuring heat resistance, and promoting recycling of refractory waste.
  • the gist is as follows. (1) In a hearth used for a moving bed furnace for producing reduced iron agglomerates by heating and reducing iron oxide agglomerates containing a reducing agent on a moving bed, magnesium oxide is formed on the upper surface of the hearth.
  • a moving hearth hearth characterized by laying refractory waste including it.
  • the reducing agent refers to a solid on-powder reducing agent such as a carbonaceous material, and is preferably coke pulverized powder coal which is easily available.
  • the iron oxide agglomerate is obtained by collecting and molding dust sludge containing metal oxide, and is preferably an agglomerate formed into an oval briquette using a double-hole molding machine.
  • the refractory waste refers to, for example, waste obtained by crushing and classifying used refractory used as a refractory material in processes such as pig iron making and steelmaking, and is preferably a refractory waste containing a large amount of MgO. This refractory waste is generated in large quantities as waste and does not cost much to purchase.
  • the heat-resistant layer made of iron oxide agglomerates refers to a heat-resistant layer formed by iron oxide agglomerates remaining on the hearth in the process of heating and reducing iron oxide agglomerates on a moving bed.
  • An iron oxide agglomerate containing carbon material is supplied onto a moving bed on which refractory waste mainly composed of magnesium oxide is laid on the upper surface of the hearth, and the iron oxide agglomerate is heated and reduced. During operation, some of the iron oxide agglomerates remain on the moving bed without being fully discharged by the discharge device. Since the remaining iron oxide agglomerate contained carbon, the carbon was vaporized and vaporized to form a porous agglomerate.
  • iron oxide agglomerates do not melt. No. Even if the iron oxide agglomerate is melted due to, for example, a partial increase in the furnace temperature or a partial decrease in the melting point of the iron oxide agglomerate, it contains magnesium oxide (desirably Contains more than 30% by weight) Since the melting point of the refractory waste is high, it does not pass through the refractory waste.
  • iron oxide agglomerates are once melted and re-solidified and fixed to the base refractory of the hearth, they will be on solid rock and difficult to be discharged by the discharge device.
  • high-melting refractory waste is disposed between the iron oxide agglomerate and the base refractory of the hearth, the furnace hearth will be melted even if the iron oxide agglomerate is once melted and re-solidified. It does not adhere to the basic refractory material, and is easily peeled off by the layer of refractory waste by the discharge device, making it easier to discharge.
  • FIG. 1 is an overall view of a hearth for a moving bed furnace according to the present invention as viewed from the side.
  • MgO used in the present invention - is a state diagram of FeO one Si0 2 based refractory debris.
  • M g 0 used in the 'present invention - Mel in the state diagram of CaO one Si0 2 based refractory debris.
  • MgO used in the present invention - is a state diagram of A1 2 0 3 _ Si0 2 based refractory debris.
  • FIG. 5 is a diagram showing a manufacturing process of refractory waste used in the present invention.
  • refractory waste 2 is laid on a hearth base refractory 1, and a heat-resistant layer 4 made of iron oxide agglomerate is present thereon.
  • the iron oxide agglomerate 3 is charged onto the hearth by the agglomerate charging device 6, and is heated and reduced to a reduced iron agglomerate 5 while the hearth moves.
  • the reduced iron agglomerate 5 is discharged outside the furnace by the agglomerate discharge device 7.
  • the thickness of the refractory waste 2 on the hearth is preferably 50 mm or more. If it is less than 50 mm, the iron oxide agglomerate once melted and re-solidified is exfoliated with a layer of refractory waste by a discharge device, and when discharged, the layer of refractory debris on the hearth base refractory disappears and the furnace This is because the floor foundation refractories may be exposed.
  • the particle size of the refractory waste 2 be at least 5 mm and the weight of 10 mm be at least 80%. If there are too many grains of 10 dragons or more, the iron oxide agglomerates that have dissolved and re-solidified are separated by a layer of refractory debris by the discharge device, and when discharged, the thickness of the refractory debris removed This is because it becomes thicker.
  • the melting temperature of the refractory debris for use in the present invention MgO in FIGS as an example - FeO _ Si0 2 system, MgO - CaO -Si0 2 system, MgO - A1 2 0 3 one Si0 This will be described with reference to a phase diagram of the two systems.
  • the melting point is more than 1500 ° C in most ranges when MgO is more than 30%.
  • a low melting point compound with a melting point of 1350 ° C or less may be formed.
  • refractory waste generated in iron making processes such as pig iron making and steel making is collected and separated for each material.
  • the separated refractory waste is subjected to primary crushing using a jaw crusher, and the refractory waste having a size of about 300 mm is reduced to a size of about 100 mm. After crushing, it is crushed in two stages from a size of about 100 mm to a size of about 20 mm.
  • a classification process is performed on the size of about 5 to 20 mm and the size of less than 5 mm, and the refractory waste with the size of 5 to 20 mm is used as the hearth material of the moving bed furnace.
  • Refractory waste of this size can also be used as an additive to caster refractory.
  • Refractory waste less than 5 mm in size can be recycled as a refractory raw material through drying, slag sorting and pulverization.
  • the hearth for moving floor furnaces which is excellent in heat resistance and uses an inexpensive material can be provided. Specifically, by laying refractory scraps of refractory containing magnesium oxide on the upper surface of the hearth, it is possible to reduce the cost of purchasing hearth materials while ensuring heat resistance.
  • refractory waste of refractory including magnesium oxide it is possible to reduce the disposal cost of refractory waste (such as landfill).
  • Refractory waste can be converted to hearth material only by crushing and classification, which is extremely simple.
  • iron oxide agglomerates are once melted and re-solidified, they do not adhere to the basic refractory of the hearth, and are easily separated by the discharge device and discharged easily.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture Of Iron (AREA)
  • Tunnel Furnaces (AREA)

Abstract

A hearth for moving floor furnace having an excellent heat resistance, using inexpensive material, and used for a moving floor furnace for manufacturing reduced iron bulk material by heating and reducing iron oxide bulk material containing coal material on a moving floor moving in the furnace, characterized in that refractory waste containing magnesium oxide is laid down on the upper surface of the hearth, wherein the content of the magnesium oxide in the refractory waste should desirably be 30 w.% or more, and a heat resistant layer formed of the iron oxide bulk material is formed on the upper surface of the refractory waste.

Description

明 細 書 移動床炉用炉床 技術分野  Description Moving hearth furnace hearth Technical field
炉内を移動する移動床の上で炭材を含有する酸化鉄塊成物を加熱 • 還元して還元鉄塊成物を製造する移動床炉に用いる炉床に関する 。 例えば、 還元鉄製造を行う回転炉床炉に用いる炉床に関する。 背景技術  Heating iron oxide agglomerates containing carbon material on a moving bed that moves in the furnace. • This relates to a hearth used in a moving bed furnace that reduces and produces reduced iron agglomerates. For example, the present invention relates to a hearth used for a rotary hearth furnace for producing reduced iron. Background art
還元鉄塊成物を製造する移動床炉に用いる炉床に関する従来技術 として、 例えば、 U. S. Pt ent 第 4 , 597 , 564 号公報に、 回転炉床炉の 炉床の上面に死焼ドロマイ ト粒からなる耐火材で作られた熱に曝さ れた面を有する炉床が開示されている。 この従来技術においては、 死焼ドロマイ ト粒からなる耐火材の厚みは 7. 5 〜15cmである。 化学 組成は、 CaO =約 54%， gO =約 38 %， Fe2 03 =約 4 %以下である 。 粒度は 100 %マイナス 1 cmの粒度を有する。 For example, US Patent No. 4,597,564 discloses dead hearth dolomite particles on the upper surface of the hearth of a rotary hearth furnace as a prior art relating to a hearth used in a moving hearth furnace for producing reduced iron agglomerates. A hearth having a surface exposed to heat made of a refractory material comprising: In this prior art, the thickness of the refractory material consisting of dead-burnt dolomite grains is 7.5 to 15 cm. Chemical composition, CaO = approximately 54%, gO = about 38%, Fe 2 0 3 = less than or equal to about 4%. The particle size has a particle size of 100% minus 1 cm.
しかし、 死焼ドロマイ ト粒は、 マグネサイ ト粒と比べて安価では あるが、 廃棄物と して発生するものではないので、 移動床炉用に別 途購入する必要があり、 その費用がかかる。  However, dead burnt dolomite grains are less expensive than magnetite grains, but they are not generated as waste, so they need to be purchased separately for moving bed furnaces and are expensive.
また、 特許第 2997459 号公報には、 酸化鉄を主成分とする炉床材 (全鉄分が 30 %以上） を移動床の基礎耐火物の上に層状に施工した 炉床が開示されている。  Further, Japanese Patent No. 2997459 discloses a hearth in which a hearth material containing iron oxide as a main component (total iron content is 30% or more) is layered on a basic refractory of a moving floor.
この従来技術においては、 炉床材を還元炉内で焼結して形成した 移動床を用い、 この焼結して形成した移動床が還元工程の操業温度 で非溶融状態である。 操業温度である 1250〜1350°Cに昇熱した時点 で焼結が完了し、 固い多孔質の炉床が形成される。 また、 この従来技術では、 基礎耐火物と前記炉床材との間に酸化 マグネシウムを主成分とする中間層を介在させている。 酸化マグネ シゥムは融点が 2800°Cと高く、 操業温度の 1300°C付近では他の耐火 物と低融点物質を生成しない。 酸化マグネシゥムを主成分とする中 間層と しては、 マグネシアク リ ンカーを破砕した粉状、 粒状、 塊状 のものが好ましいと している。 In this conventional technique, a moving bed formed by sintering a hearth material in a reduction furnace is used, and the moving bed formed by sintering is in a non-molten state at the operating temperature of the reduction step. When the temperature rises to the operating temperature of 1250 to 1350 ° C, sintering is completed and a hard porous hearth is formed. In this prior art, an intermediate layer mainly composed of magnesium oxide is interposed between a basic refractory and the hearth material. Magnesium oxide has a high melting point of 2800 ° C, and does not produce other refractories and low-melting substances near the operating temperature of 1300 ° C. The intermediate layer mainly composed of magnesium oxide is preferably in the form of powder, granules, or lump obtained by crushing magnesia clinker.
しかし、 酸化鉄を主成分とする炉床材ゃ酸化マグネシウムを主成 分とする中間層を購入する必要があるため、 購入費用がかかるとい う問題点があった。  However, it was necessary to purchase a hearth material containing iron oxide as a main component and an intermediate layer containing magnesium oxide as a main component.
一方、 製銑や鉄鋼などの製鉄工程では、 炉および容器物の保護の ために、 耐火物が内張り されている。 その耐火物は損耗するので定 期的に張り替える必要があり、 粗鋼トン当たり約 7 kgの耐火物屑が 発生する。 この耐火物屑の発生量はマグネシア （酸化マグネシウム ) 系が最も多く全体の約 40 %を占める。  On the other hand, in the iron making process such as pig iron and steel, refractories are lined to protect the furnace and vessel. The refractory wears out and needs to be replaced periodically, and about 7 kg of refractory waste is generated per ton of crude steel. Magnesia (magnesium oxide) is the largest source of this refractory waste, accounting for about 40% of the total.
しかし、. 現状の処理及び利用状況は、 日本国内においては、 約 68 %が埋立されるか保管されるかであり、 有価物として活用されてい るのは僅か約 15 %のみである。 特に最近は、 埋立地不足、 埋立費用 の高騰が問題になっている。 発明の開示  However, the current status of treatment and use is that about 68% is landfilled or stored in Japan, and only about 15% is used as valuable resources. In particular, shortages of landfills and soaring landfill costs have recently become problems. Disclosure of the invention
本発明は、 移動床炉に用いる炉床に関する前述のよ うな従来技術 の問題点を解決し、 耐熱性に優れ、 かつ、 安価な材料を用いた炉床 を提供することを課題とする。  An object of the present invention is to solve the above-mentioned problems of the prior art relating to a hearth used for a moving hearth furnace, and to provide a hearth using an inexpensive material that is excellent in heat resistance.
本発明は、 移動床用炉床の上面に酸化マグネシゥムを含む耐火物 屑を敷設することで、 耐熱性を確保しつつ炉床材の購入費用を削減 する と共に、 耐火物屑のリサイクルを推進するものであり、 その要 旨は下記のとおりである。 ( 1 ) 還元剤を含有する酸化鉄塊成物を移動床の上で加熱 ·還元 して還元鉄塊成物を製造する移動床炉に用いる炉床において、 前記 炉床の上面に酸化マグネシウムを含む耐火物屑を敷設したことを特 徴とする移動床炉用炉床。 The present invention lays refractory waste including magnesium oxide on the upper surface of a hearth for a moving floor, thereby reducing the cost of purchasing hearth materials while ensuring heat resistance, and promoting recycling of refractory waste. The gist is as follows. (1) In a hearth used for a moving bed furnace for producing reduced iron agglomerates by heating and reducing iron oxide agglomerates containing a reducing agent on a moving bed, magnesium oxide is formed on the upper surface of the hearth. A moving hearth hearth characterized by laying refractory waste including it.
( 2 ) 前記耐火物屑中の酸化マグネシゥムの含有量が 30質量％以 上であることを特徴とする （ 1 ) に記載の移動床炉用炉床。  (2) The hearth for a moving bed furnace according to (1), wherein the content of magnesium oxide in the refractory waste is 30% by mass or more.
( 3 ) 前記耐火物屑の上面に酸化鉄塊成物からなる耐熱層を有す ることを特徴とする （ 1 ) または （ 2 ) に記載の移動床炉用炉床。  (3) The hearth for a moving floor furnace according to (1) or (2), further comprising a heat-resistant layer made of iron oxide agglomerates on the upper surface of the refractory waste.
ここに、 還元剤とは、 炭材などの粉上固形還元材をいい、 入手し 易い粉コークスゃ粉石炭が好ましい。  Here, the reducing agent refers to a solid on-powder reducing agent such as a carbonaceous material, and is preferably coke pulverized powder coal which is easily available.
酸化鉄塊成物とは、 金属酸化物を含むダス トゃスラジを回収して 成型したものであり、 ダブル口ール成型機を用いて楕円形ブリケッ トに成型した塊成物が好ましい。  The iron oxide agglomerate is obtained by collecting and molding dust sludge containing metal oxide, and is preferably an agglomerate formed into an oval briquette using a double-hole molding machine.
耐火物屑とは、 例えば、 製銑や製鋼などの工程おいて耐火材と し て用いられた使用済みの耐火物を破碎 · 分級した屑をいい、 MgO を 多く含む耐火物の屑が好ましい。 この耐火物屑は廃棄物として多量 に発生するものであり、 購入費用がかからない。  The refractory waste refers to, for example, waste obtained by crushing and classifying used refractory used as a refractory material in processes such as pig iron making and steelmaking, and is preferably a refractory waste containing a large amount of MgO. This refractory waste is generated in large quantities as waste and does not cost much to purchase.
酸化鉄塊成物からなる耐熱層とは、 酸化鉄塊成物を移動床で加熱 - 還元する過程で炉床の上に残存した酸化鉄塊成物が形成する耐熱 層をレヽう。  The heat-resistant layer made of iron oxide agglomerates refers to a heat-resistant layer formed by iron oxide agglomerates remaining on the hearth in the process of heating and reducing iron oxide agglomerates on a moving bed.
炉床の上面に酸化マグネシゥムを主成分とする耐火物屑を敷設し た移動床の上に、 炭材を含有する酸化鉄塊成物を供給し、 前記酸化 鉄塊成物を加熱 · 還元する操業を行う と、 酸化鉄塊成物の一部が排 出装置で排出しきれずに、 移動床の上に残存する。 この残存した酸 化鉄塊成物には、 炭素が含有していたため、 前記炭素が燃焼気化し 、 多孔質の塊成物となる。  An iron oxide agglomerate containing carbon material is supplied onto a moving bed on which refractory waste mainly composed of magnesium oxide is laid on the upper surface of the hearth, and the iron oxide agglomerate is heated and reduced. During operation, some of the iron oxide agglomerates remain on the moving bed without being fully discharged by the discharge device. Since the remaining iron oxide agglomerate contained carbon, the carbon was vaporized and vaporized to form a porous agglomerate.
通常の操業温度 （1200〜1350°C ) では、 酸化鉄塊成物は溶融しな い。 万一炉内温度が部分的に高温になる、 若しくは前記酸化鉄塊成 物の融点が部分的に低下する等して、 前記酸化鉄塊成物が溶融した 場合でも、 酸化マグネシウムを含む （望ましくは含有量が 30%重量 %以上） 耐火物の耐火物屑の融点が高いため、 耐火物屑を通過する ことはない。 At normal operating temperatures (1200-1350 ° C), iron oxide agglomerates do not melt. No. Even if the iron oxide agglomerate is melted due to, for example, a partial increase in the furnace temperature or a partial decrease in the melting point of the iron oxide agglomerate, it contains magnesium oxide (desirably Contains more than 30% by weight) Since the melting point of the refractory waste is high, it does not pass through the refractory waste.
酸化鉄塊成物が一旦溶解し再凝固して、 炉床の基礎耐火物と固着 した場合には、 強固な岩盤上になり、 排出装置で排出するのが困難 になる。 前述のよ うに酸化鉄塊成物と炉床の基礎耐火物との間に高 融点の耐火物屑を配した場合、 前記酸化鉄塊成物が一旦溶解し再凝 固しても、 炉床の基礎耐火物と固着せず、 排出装置によ り耐火物屑 の層で容易に剥離させ、 排出するのが容易になる。 図面の簡単な説明  If iron oxide agglomerates are once melted and re-solidified and fixed to the base refractory of the hearth, they will be on solid rock and difficult to be discharged by the discharge device. As described above, if high-melting refractory waste is disposed between the iron oxide agglomerate and the base refractory of the hearth, the furnace hearth will be melted even if the iron oxide agglomerate is once melted and re-solidified. It does not adhere to the basic refractory material, and is easily peeled off by the layer of refractory waste by the discharge device, making it easier to discharge. BRIEF DESCRIPTION OF THE FIGURES
図 1 は、 本発明の移動床炉用炉床を横からみた全体図である。 図 2は、 本発明に用いる MgO - FeO 一 Si02系耐火物屑の状態図で ある。 FIG. 1 is an overall view of a hearth for a moving bed furnace according to the present invention as viewed from the side. 2, MgO used in the present invention - is a state diagram of FeO one Si0 2 based refractory debris.
図 3は、 '本発明に用いる Mg0 - CaO 一 Si02系耐火物屑の状態図で める。 3, M g 0 used in the 'present invention - Mel in the state diagram of CaO one Si0 2 based refractory debris.
図 4は、 本発明に用いる MgO — A12 03 _ Si02系耐火物屑の状態図 である。 4, MgO used in the present invention - is a state diagram of A1 2 0 3 _ Si0 2 based refractory debris.
図 5は、 本発明に用いる耐火物屑の製造工程を示す図である。 発明を実施するための最良の形態  FIG. 5 is a diagram showing a manufacturing process of refractory waste used in the present invention. BEST MODE FOR CARRYING OUT THE INVENTION
本発明における移動床炉用炉床の実施の形態を図 1によ り詳細に 説明する。 炉床の構造は、 炉床基礎耐火物 1の上に、 耐火物屑 2が 敷設されており、 その上に、 酸化鉄塊成物からなる耐熱層 4が存在 する。 酸化鉄塊成物 3は、 塊成物装入装置 6によ り炉床上に装入され、 炉床が移動する過程で、 加熱 ' 還元されて、 還元鉄塊成物 5に変化 する。 還元鉄塊成物 5は、 塊成物排出装置 7によ り、 炉外に排出さ れる。 An embodiment of a hearth for a moving bed furnace according to the present invention will be described in detail with reference to FIG. In the hearth structure, refractory waste 2 is laid on a hearth base refractory 1, and a heat-resistant layer 4 made of iron oxide agglomerate is present thereon. The iron oxide agglomerate 3 is charged onto the hearth by the agglomerate charging device 6, and is heated and reduced to a reduced iron agglomerate 5 while the hearth moves. The reduced iron agglomerate 5 is discharged outside the furnace by the agglomerate discharge device 7.
炉床上の耐火物屑 2の層厚は、 50mm以上が望ましい。 50mm未満の 場合、 一旦溶解し再凝固した酸化鉄塊成物を排出装置により耐火物 屑の層で剥離させ、 排出したときに、 炉床基礎耐火物上の耐火物屑 の層が無くなり、 炉床基礎耐火物が露出する可能性があるからであ る。  The thickness of the refractory waste 2 on the hearth is preferably 50 mm or more. If it is less than 50 mm, the iron oxide agglomerate once melted and re-solidified is exfoliated with a layer of refractory waste by a discharge device, and when discharged, the layer of refractory debris on the hearth base refractory disappears and the furnace This is because the floor foundation refractories may be exposed.
耐火物屑 2の粒径は 5 mm以上且つ 10mmが重量で 80 %以上であるこ とが望ましい。 10龍以上の粒があまりに多い場合、 ー且溶解し再凝 固した酸化鉄塊成物を排出装置によ り耐火物屑の層で剥離させ、 排 出したときに、 耐火物屑の剥離厚さが厚くなるからである。  It is desirable that the particle size of the refractory waste 2 be at least 5 mm and the weight of 10 mm be at least 80%. If there are too many grains of 10 dragons or more, the iron oxide agglomerates that have dissolved and re-solidified are separated by a layer of refractory debris by the discharge device, and when discharged, the thickness of the refractory debris removed This is because it becomes thicker.
次に、 本発明に用いる耐火物屑の溶融温度について、 実施例と し て図 2〜図 4の MgO — FeO _ Si02系、 MgO - CaO —Si02系、 MgO - A12 03 一 Si02系の状態図を用いて説明する。 Next, the melting temperature of the refractory debris for use in the present invention, MgO in FIGS as an example - FeO _ Si0 2 system, MgO - CaO -Si0 2 system, MgO - A1 2 0 3 one Si0 This will be described with reference to a phase diagram of the two systems.
図 2は、 MgO - FeO _ Si02系状態図であり、 図 3は、 MgO - CaO — Si02系状態図であり、 図 4は、 MgO - A12 03 _ S i02系状態図であ る。 これらの状態図によると、 MgO が 30%以上では殆どの範囲で融 点が 1500°C以上である。 それに対し、 MgO が 30%未満の場合、 融点 が 1350°C以下の低融点化合物が生成される可能性がある。 2, MgO - FeO _ Si0 a 2 phase diagram, FIG. 3, MgO - CaO - Si0 a 2 phase diagram, FIG. 4, MgO - A1 2 0 3 _ in S i0 2 phase diagram is there. According to these phase diagrams, the melting point is more than 1500 ° C in most ranges when MgO is more than 30%. On the other hand, if the content of MgO is less than 30%, a low melting point compound with a melting point of 1350 ° C or less may be formed.
次に、 炉床材として用いる耐火物屑の製造方法について、 図 5を 用いて説明する。  Next, a method for producing refractory waste used as a hearth material will be described with reference to FIG.
まず、 製銑や製鋼などの製鉄プロセスで発生する耐火物屑を回収 し、 材料ごとに分別処理を行う。  First, refractory waste generated in iron making processes such as pig iron making and steel making is collected and separated for each material.
分別処理された耐火物屑は、 ジョークラッシヤーを用いて一次破 砕を行い、 300 mm程度の大きさの耐火物屑を 100 mm程度の大きさに した後、 100 mm程度の大きさから 20mm程度の大きさに二段階に分け て破砕する。 The separated refractory waste is subjected to primary crushing using a jaw crusher, and the refractory waste having a size of about 300 mm is reduced to a size of about 100 mm. After crushing, it is crushed in two stages from a size of about 100 mm to a size of about 20 mm.
次に、 5〜 20mm程度の大きさのものと 5 mm未満の大きさのものに 分級処理を行い、 5〜 20mmの大きさの耐火物屑を移動床炉の炉床材 として用いる。  Next, a classification process is performed on the size of about 5 to 20 mm and the size of less than 5 mm, and the refractory waste with the size of 5 to 20 mm is used as the hearth material of the moving bed furnace.
なお、 この大きさの耐火物屑はキャスタプル耐火材の添加材料と しても使う こ とができる。  Refractory waste of this size can also be used as an additive to caster refractory.
5 mm未満の大きさの耐火物屑は乾燥処理、 スラグ選別 ·粉砕処理 を経て、 耐火物原料と してリサィクルすることも可能である。 産業上の利用可能性  Refractory waste less than 5 mm in size can be recycled as a refractory raw material through drying, slag sorting and pulverization. Industrial applicability
本発明によ り、 耐熱性に優れ、 かつ、 安価な材料を用いた移動床 炉用炉床を提供することができる。 具体的には、 炉床の上面に酸化 マグネシウムを含む耐火物の耐火物屑を敷設することで、 耐熱性を 確保しつつ炉床材の購入費用を削減できる。  ADVANTAGE OF THE INVENTION According to this invention, the hearth for moving floor furnaces which is excellent in heat resistance and uses an inexpensive material can be provided. Specifically, by laying refractory scraps of refractory containing magnesium oxide on the upper surface of the hearth, it is possible to reduce the cost of purchasing hearth materials while ensuring heat resistance.
また、 酸化マグネシゥムを含む耐火物の耐火物屑を用いることで 、 耐火物屑の処理費用 （埋立等） を削減できる。  In addition, by using refractory waste of refractory including magnesium oxide, it is possible to reduce the disposal cost of refractory waste (such as landfill).
耐火物屑の炉床材料化は、 破砕、 分級するのみで良く、 極めて簡 便である。  Refractory waste can be converted to hearth material only by crushing and classification, which is extremely simple.
さ らに、 酸化鉄塊成物が一旦溶解し再凝固しても、 炉床の基礎耐 火物と固着せず、 排出装置で容易に剥離させ、 排出するのが容易に なる。  Furthermore, even if the iron oxide agglomerates are once melted and re-solidified, they do not adhere to the basic refractory of the hearth, and are easily separated by the discharge device and discharged easily.

Claims

請 求 の 範 囲 The scope of the claims
1 . 還元剤を含有する酸化鉄塊成物を移動床の上で加熱 · 還元し て還元鉄塊成物を製造する移動床炉に用いる炉床において、 前記炉 床の上面に酸化マグネシウムを含む耐火物屑を敷設したことを特徴 とする移動床炉用炉床。 1. An iron oxide agglomerate containing a reducing agent is heated and reduced on a moving bed to produce a reduced iron agglomerate in a moving hearth furnace, wherein the upper surface of the hearth contains magnesium oxide. A hearth for a moving-bed furnace, which is provided with refractory waste.
2 . 前記耐火物屑中の酸化マグネシウムの含有量が 30質量％以上 であることを特徴とする請求項 1 に記載の移動床炉用炉床。  2. The hearth for a moving bed furnace according to claim 1, wherein the content of magnesium oxide in the refractory waste is 30% by mass or more.
3 . 前記耐火物屑の上面に酸化鉄塊成物からなる耐熱層を有する ことを特徴とする請求項 1 または請求項 2に記載の移動床炉用炉床  3. The hearth for a moving floor furnace according to claim 1 or 2, further comprising a heat-resistant layer made of iron oxide agglomerates on the upper surface of the refractory waste.
PCT/JP2002/008754 2001-08-30 2002-08-29 Hearth for moving floor furnace WO2003018849A1 (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5130214A (en) * 1974-09-07 1976-03-15 Koa Taika Kogyo Kk
JPS5247017A (en) * 1975-10-12 1977-04-14 Daido Steel Co Ltd Manufacture of mgo refractories
US4597564A (en) * 1985-05-23 1986-07-01 The International Metals Reclamation Company, Inc. Rotary hearth
JPH10203862A (en) * 1997-01-16 1998-08-04 Shinagawa Refract Co Ltd Magnesium-chromium brick fired at high temperature
JPH11304369A (en) * 1998-04-24 1999-11-05 Nippon Steel Corp Construction method of refractory lining of molten metal container
US6254665B1 (en) * 1998-04-11 2001-07-03 Kobe Steel, Ltd. Method for producing reduced iron agglomerates
US20010032527A1 (en) * 1998-09-25 2001-10-25 Mitsubishi Heavy Industries, Ltd. Method of producing reduced iron and production facilities therefor

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5130214A (en) * 1974-09-07 1976-03-15 Koa Taika Kogyo Kk
JPS5247017A (en) * 1975-10-12 1977-04-14 Daido Steel Co Ltd Manufacture of mgo refractories
US4597564A (en) * 1985-05-23 1986-07-01 The International Metals Reclamation Company, Inc. Rotary hearth
JPH10203862A (en) * 1997-01-16 1998-08-04 Shinagawa Refract Co Ltd Magnesium-chromium brick fired at high temperature
US6254665B1 (en) * 1998-04-11 2001-07-03 Kobe Steel, Ltd. Method for producing reduced iron agglomerates
JPH11304369A (en) * 1998-04-24 1999-11-05 Nippon Steel Corp Construction method of refractory lining of molten metal container
US20010032527A1 (en) * 1998-09-25 2001-10-25 Mitsubishi Heavy Industries, Ltd. Method of producing reduced iron and production facilities therefor

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