JP3751819B2

JP3751819B2 - Reduced iron or non-ferrous metal production facility, and reduced iron or non-ferrous metal production method

Info

Publication number: JP3751819B2
Application number: JP2000313347A
Authority: JP
Inventors: 雅孝立石; 理彦鉄本
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 1999-10-15
Filing date: 2000-10-13
Publication date: 2006-03-01
Anticipated expiration: 2020-10-13
Also published as: JP2001181721A

Description

【０００１】
【発明の属する技術分野】
本発明は、酸化鉄含有材料と炭材含有還元材料とからなる炭材内装塊成物を移動床型還元炉に装入し、加熱還元して還元鉄を製造する還元鉄製造設備及び還元鉄製方法に関するものであり、また、非鉄金属製造設備及び非鉄金属製造方法に関するものである。
【０００２】
【従来の技術】
蓄熱式バーナは二つの吸排気部を持ち、一方の吸排気部では燃料と燃焼用空気を燃焼させることによって燃焼側として使用し、他方の吸排気部ではバーナで加熱され雰囲気ガスや燃焼ガスなどの高温ガスを吸入し外部に排気する排気側として使用する。これら吸排気部には、それぞれ蓄熱体が設置され、排気側の吸排気部で高温ガスを吸入したときに蓄熱体に蓄熱させ、燃焼側の吸排気部でバーナとして使用する場合に、蓄熱体に蓄熱された熱で燃料や燃焼用空気を予熱する。そして、この燃焼側、排気側を切り替えることにより高温ガスである排ガスを利用し熱効率を高めるものである。このため従来より金属加熱炉、熱処理炉等の工業用加熱炉、あるいは取鍋の耐火物の乾燥や予熱用に蓄熱式バーナが用いられている。
【０００３】
しかし、一般に、炉内の高温ガス中にダスト成分や揮発性物質成分が多く含まれる場合には、蓄熱体の早期劣化や揮発性物質による蓄熱体の汚染が懸念されるため蓄熱式バーナの使用が難しいとされていた。
【０００４】
また、炉内が可燃性ガスによって還元雰囲気になっている場合は、そのまま蓄熱式バーナの排気側の吸排気部で吸気すると、可燃性ガスを吸入することによって、蓄熱体の被毒や可燃性ガスをそのまま炉外へ排出することとなるため環境問題となる等の問題があった。
【０００５】
このため特開平９−１２６４４３号公報ではダスト成分である酸化鉄を捕集するため、炉と蓄熱体との間に捕集装置を設けており、さらに、蓄熱体としてセラミックス等の耐食性の高い材料を用いているものが開示されている。
【０００６】
また、特開平７−１０３４３３号公報では、排気側から燃焼側へ切り替える前に、排気側の配管や蓄熱式バーナ内を不活性ガスで置換することによって爆発を防いでいるものが開示されている。
【０００７】
【発明が解決しようとする課題】
ところが、捕集装置や不活性ガスによる置換では、このための装置が必要となり、蓄熱式バーナの構造が複雑になるとともに、蓄熱式バーナの設置スペースが大きくなり、イニシャルコストが増大する。また、蓄熱式バーナを排気側から燃焼側へ切り替えるたびにダスト除去や不活性ガスによる置換をする必要があり、切り替えに時間がかかる等の問題がある。
【０００８】
また、蓄熱体としてセラミックス等の耐食性の高い材料を用いた場合は、耐食性はあるものの高価であり、炉内に揮発性成分やダスト成分が多い場合には、揮発性成分やダスト成分が付着することによって頻繁な取り替えを余儀なくされ、ランニングコストが増大するとともに、使用済みの蓄熱体を廃棄することによる環境悪化等の問題がある。
【０００９】
特に、酸化鉄含有材料と炭素含有還元材料とからなる炭材内装塊成物を移動床型還元炉に装入し、加熱還元して還元鉄を製造する還元鉄製造設備においては、原料中の酸化鉄等が粉体となりダストとして炉内に存在しやすく、また、原料として揮発性成分を多量に含んでいるものを使用する場合がある。さらに、還元するためには炉内の雰囲気を還元雰囲気とする必要があり、還元鉄製造設備ではこれを原料中の炭素含有還元材料から発生する可燃性ガスや天然ガスなどの可燃性ガスを吹き込むことによって還元性雰囲気としている。このため、加熱を開始する還元工程前半部では揮発性成分が多量に揮発しやすく、また、還元工程後半部では再酸化を防止し、高金属化率を維持するため十分な還元雰囲気に保持する必要があるので蓄熱式バーナが使用されていなかった。
【００１０】
本発明は、上記のような問題を解決し、蓄熱式バーナを用いた還元鉄製造設備提供することを目的とする。
【００１１】
【課題を解決するための手段】
上記課題を解決するための手段として、本発明の請求項１は、酸化鉄含有材料と炭素含有還元材料とからなる炭材内装塊成物を移動床型還元炉に装入し、加熱還元して還元鉄を製造する還元鉄製造設備において、前記移動床型還元炉が、前記炭材内装塊成物を装入する塊成物装入部と、前記還元鉄を排出する還元鉄排出部と、前記塊成物装入部から前記還元鉄排出部までの還元工程の間に炉内排ガスを排出するガス排出部と、前記還元工程の後半部であり前記ガス排出部と前記還元鉄排出部の間に前記移動床型還元炉の加熱源としての蓄熱式バーナとを備え、且つ、前記蓄熱式バーナが、前記移動床型還元炉の上部に設置され、前記移動床型還元炉の炉床に対してほぼ水平もしくはやや上向きに配置されていることを特徴とする還元鉄製造設備である。
【００１２】
本発明の請求項２は、さらに、前記還元工程の前半部であり前記塊成物装入部と前記ガス排出部との間にも蓄熱式バーナが備えられていることを特徴とする還元鉄製造設備である。
【００１３】
本発明の請求項３は、前記還元工程の前半部の蓄熱式バーナが、前記炭材内装塊成物の表面温度が１２５０℃以下の領域である位置に設置してあり、前記ガス排出部が、前記炭材内装塊成物の表面温度が１２５０℃以下の領域の後方の位置に設置してあることを特徴とする還元鉄製造設備である。
【００１４】
本発明の請求項４は、前記蓄熱式バーナが、前記還元工程の後半部であり前記ガス排出部と前記還元鉄排出部の間に備えられており、且つ、前記蓄熱式バーナが、前記移動床型還元炉の上部に設置され、前記移動床型還元炉の炉床に対してほぼ水平もしくはやや上向きに配置されていることを特徴とする還元鉄製造設備である。
【００１５】
本発明の請求項５は、前記還元工程の後半部の蓄熱式バーナの燃焼ガスが酸化性雰囲気で、前記炭材内装塊成物を覆う雰囲気が還元性雰囲気であることを特徴とする還元鉄製造設備である。
【００１６】
【００１７】
本発明の請求項５は、前記還元工程の前半部の蓄熱式バーナが、燃料と燃焼用酸素含有ガスとを蓄熱体を介し燃焼させる第一の蓄熱式バーナと、燃焼用酸素含有ガスのみを蓄熱体を介し前記還元炉内に吹込んで該還元炉内の可燃性ガスの一部を燃焼させる第二の蓄熱式バーナとを組み合わせたものであって、前記第二の蓄熱式バーナを前記第一の蓄熱式バーナの設置位置より下方に設置することを特徴とする還元鉄製造設備である。
【００１８】
本発明の請求項６は、前記還元工程の前半部の蓄熱式バーナが、燃焼用酸素含有ガスのみを蓄熱体を介し前記還元炉内に吹込んで該還元炉内の可燃性ガスの一部を燃焼させる蓄熱式バーナであり、さらに燃料と燃焼用酸素含有ガスとを燃焼させる、蓄熱式バーナ以外の他の形式のバーナを具備する還元鉄製造設備であって、前記蓄熱式バーナを前記バーナの設置位置より下方に配置することを特徴とする還元鉄製造設備である。
【００１９】
本発明の請求項７は、蓄熱式バーナの蓄熱体が、前記還元鉄製造設備で製造された還元鉄または鉄鉱石塊成物であることを特徴とする還元鉄製造設備である。
【００２０】
本発明の請求項８は、前記酸化鉄含有材料の一部または全部が非鉄金属酸化物であることを特徴とする非鉄金属製造設備である。
【００２１】
本発明の請求項９は、酸化鉄含有材料と炭素含有還元材料とからなる炭材内装塊成物を移動床型還元炉に装入し、炉内で加熱還元して還元鉄を製造する還元鉄製造方法において、前記炭材内装塊成物の装入から排出までの還元工程の前半部にて炉内の排ガスを排出し、前記炭材内装塊成物を、前記移動床型還元炉の上部に設置され、前記移動床型還元炉の炉床に対してほぼ水平もしくはやや上向きに配置されている蓄熱式バーナで加熱し、前記蓄熱式バーナの燃焼ガスが酸化性雰囲気とすることによって該蓄熱式バーナの近傍の雰囲気を酸化性雰囲気とし、前記炭材内装塊成物内部から発生する還元性ガスを燃焼させながら該炭材内装塊成物の近傍を覆う雰囲気を還元性雰囲気に保ちながら還元鉄を製造することを特徴とする還元鉄製造方法である。
【００２２】
本発明の請求項１０は、前記蓄熱式バーナが、燃料と燃焼用酸素含有ガスとを蓄熱体を介し燃焼させる第一の蓄熱式バーナと、燃焼用酸素含有ガスのみを蓄熱体を介し前記還元炉内に吹込んで該還元炉内の可燃性ガスの一部を燃焼させる第二の蓄熱式バーナとを組み合わせたものであって、前記塊成物装入部から前記還元工程の前半部までの間に、前記第二の蓄熱式バーナを前記第一の蓄熱式バーナの設置位置より下方に設置することを特徴とする還元鉄製造方法である。
【００２３】
本発明の請求項１１は、前記蓄熱式バーナが、燃焼用酸素含有ガスのみを蓄熱体を介し前記還元炉内に吹込んで該還元炉内の可燃性ガスの一部を燃焼させる蓄熱式バーナであり、さらに燃料と燃焼用酸素含有ガスとを燃焼させる、蓄熱式バーナ以外の他の形式のバーナを具備する還元鉄製造方法であって、前記塊成物装入部から前記還元工程の前半部までの間に、前記蓄熱式バーナを前記バーナの設置位置より下方に配置することを特徴とする還元鉄製造方法である。
【００２４】
本発明の請求項１２は、前記蓄熱式バーナの蓄熱体が、前記還元鉄製造方法で製造された還元鉄または鉄鉱石塊成物であることを特徴とする還元鉄製造方法である。
【００２５】
本発明の請求項１３は、前記酸化鉄含有材料の一部または全部が非鉄金属酸化物であることを特徴とする非鉄金属製造方法である。
【００２６】
請求項１、９の発明によれば、従来使用されなかった還元鉄製造設備に蓄熱式バーナの使用が可能となり、炉内排ガスの有効利用が可能であるので熱効率を高め、コストダウンが可能である。
【００２７】
また、請求項２、３の発明によれば、蓄熱式バーナを塊成物装入部からガス排気部の間の揮発性成分があまり揮発しない還元工程前半の位置に設置することで、揮発性成分による蓄熱体の劣化がなく、ダスト捕集装置が不要となり、蓄熱式バーナ設置スペースが小さくてすむとともに、イニシャルコストを増大させることがない。
【００２８】
さらに、請求項１、４、９の発明によれば、蓄熱式バーナをガス排出部から還元鉄排出部の間の還元工程後半の位置に設置し、蓄熱式バーナ近傍と炭材内装塊成物近傍の雰囲気をそれぞれ酸化性雰囲気と還元性雰囲気に保つことで、不活性ガスによる置換のための装置が不要となり蓄熱式バーナ設置スペースが小さくてすむとともに、蓄熱式バーナを排気側から燃焼側へ切り替える時間が短くてすむ。さらに、前記移動床型還元炉の上部に設置され、前記移動床型還元炉の炉床に対してほぼ水平もしくはやや上向きに配置することで、酸化性ガスが炭材内装塊成物表面に直接当たることがなく、炭材内装塊成物近傍の雰囲気を乱すことがないので還元された炭材内装塊成物の再酸化を防止し高金属化率を維持できる。
【００２９】
請求項５、１０の発明によれば、第二の蓄熱式バーナを第一の蓄熱式バーナと炉床間に設置することで、炭材内装物の内部から発生する還元性ガスを、該炭材内装塊成物の近傍で効率的に燃焼させることができる。このため、該炭材内装塊成化物への伝熱効果が向上し、該炭材内装塊成化物の加熱、還元反応が促進される。したがって、還元鉄製造の生産性が向上する一方、バーナ排ガス量の低減と燃料原単位の向上を図ることができる。
【００３０】
請求項６、１１の発明によれば、上記第一の蓄熱式バーナの替わりに蓄熱式バーナ以外の他の形式のバーナを使用することができ、蓄熱式バーナをバーナと炉床間に設置することで、炭材内装塊成化物の内部から発生する還元性ガスを、該炭材内装塊成化物の近傍で効率的に燃焼させることができる。
【００３１】
また、さらに請求項７、１２の発明によれば、蓄熱体として鉄鉱石塊成物または還元鉄を使用するため、安価であり、たとえ揮発性成分やダスト成分が付着したとしても、廃棄することなく、本発明の還元鉄製造設備の原材料として使用できるためランニングコストが増大することがないとともに、使用済みの蓄熱体を廃棄することによる環境悪化等の問題がない。
【００３２】
そして、請求項８、１３の発明によれば、還元鉄だけではなく非鉄金属の製造にも蓄熱式バーナが使用できる。
【００３３】
【発明の実施の形態】
本発明の還元鉄製造設備では、図７に示すような蓄熱式バーナを用いる。蓄熱式バーナ２は二つの吸排気部（２ａ、２ｂ）を持つ。まず、図７（ａ）の状態のように、一方の吸排気部２ａでは、燃料と燃焼用空気が燃料配管３から燃料切替弁５ａをへて蓄熱体７ａを介し、燃焼させることによって燃焼側として使用する。他方の吸排気部２ｂでは吸排気部２ａの燃焼側で加熱された雰囲気ガスや燃焼ガスなどの高温ガスを吸入し、蓄熱体７ｂを介し排ガス切替弁６ｂをへて排ガス配管４ｂから外部に排気される。このとき、高温ガスの顕熱が蓄熱体７ｂに蓄熱される。この状態では、燃料切替弁５ｂ、排ガス切替弁６ａは閉じられている。そして一定時間経過すると、図７（ｂ）の状態に切り替えられ、他方の吸排気部２ｂでは、燃料と燃焼用空気が燃料配管３から燃料切替弁５ｂをへて蓄熱体７ｂを介し、燃焼させることによって燃焼側として使用する。一方の吸排気部２ａでは、吸排気部２ｂの燃焼側で加熱された雰囲気ガスや燃焼ガスなどの高温ガスを吸入し、蓄熱体７ａを介し排ガス切替弁６ａをへて排ガス配管４ａから外部に排気される。このとき、蓄熱体７ｂに蓄熱された熱により燃料と燃焼用空気が加熱されるとともに高温ガスの顕熱が蓄熱体７ａに蓄熱される。この状態では、燃料切替弁５ａ、排ガス切替弁６ｂは閉じられている。そして一定時間経過すると再度、図７（ａ）の状態に切り替えられる。これを繰り返すことによって高温ガスの顕熱を利用して熱効率を高めるものである。
【００３４】
次に、上記蓄熱式バーナを用いた本発明に係わる第１の実施の形態を図１に示す。本発明の還元鉄製造設備では、移動炉床炉として回転炉床炉を用いる。原料となる酸化鉄含有材料と炭素含有還元材料は予め混合され、必要に応じてバインダーを添加されて球形ペレットやブリケット状の炭材内装塊成物１に成形される。この炭材内装塊成物１は塊成物挿入部１０から装入され、必要に応じて図示しない均し機で均される。そして、床炉８上で塊成物挿入部１０から還元鉄排出部１１へ移動する間の還元工程において還元され還元鉄となる。
【００３５】
炉内は、塊成物挿入部１０から還元鉄排出部１１の間に設置された蓄熱式バーナ２の燃焼側吸排気部によって最高１３５０℃から１４００℃程度に加熱されており、炉床が１回転する間に所定の金属化率になるように加熱還元され、還元鉄として還元鉄排出部１１から炉外に排出される。
【００３６】
炉内の排ガスは、塊成物挿入部１０と還元鉄排出部１１との間に設けられたガス排出部１２から排出されるとともに蓄熱式バーナ２の排気側吸排気部からも排出される。
【００３７】
このように、蓄熱式バーナ２を用いることによって、蓄熱式バーナ２の吸排気部（２ａ、２ｂ）を燃焼側吸排気部と排気側吸排気部として交互に燃焼と排気（蓄熱）を繰り返すことによって、蓄熱体を介してバーナの燃料や燃焼用空気を予熱するため熱効率が向上する。
【００３８】
炭材内装塊成物１は装入装置から装入されると、高温の炉内ガスにより急激に昇温する。このとき、炭材内装塊成物１に含まれる揮発性成分が揮発する。これは図３に示すように、炭材内装塊成物１の表面温度が約１２５０℃を超えると炭材内装塊成物１の原料に含まれている代表的な揮発性物質である亜鉛（Ｚｎ）が急激に揮発し始める。この揮発性物質を含んだガスを蓄熱式バーナ２の排気側から排気すると、蓄熱体に揮発物が付着して目詰まりを起こし蓄熱体の蓄熱性能を低下させることになる。したがって、本発明で用いられる蓄熱式バーナ２は、還元工程の前半部であり、炭材内装塊成物より揮発性物質があまり揮発していない領域に設置され、前記表面温度が１２５０℃以下である領域に設置することが好ましい。
【００３９】
そして、本発明では、蓄熱式バーナ２を設置している炭材内装塊成物１の表面温度が１２５０℃以下である領域の後方にガス排出部１２を設けるのがよい。ガス排出部１２をこの位置に設けることによって、表面温度が１２５０℃以上に昇温した炭材内装塊成物１から揮発した揮発性物質を、その発生部位より前に流すことなく、ガス排出部１２から炉外に排出することができるため、還元工程の前半部に設置された蓄熱式バーナ２が揮発物を含んだガスを排出することはない。したがって、蓄熱式バーナ２の蓄熱体には付着せず、蓄熱体の劣化や蓄熱体が目詰まりを起こし蓄熱性能を低下させることはない。また、炉内のガス流れをガス排出部１２に向けることで、蓄熱式バーナ２へダストが流れることを防止でき、蓄熱式バーナ２がダストを吸い込むことはなく、蓄熱体へのダスト付着による蓄熱体の劣化や蓄熱体が目詰まりを起こし蓄熱性能を低下させることはない。
【００４０】
次に、本発明に係わる第２の実施の形態を図２に示す。本発明では図２に示すように、蓄熱式バーナ２は還元工程の後半部に設置する。炭材内装塊成物１は還元が進むと炭材内装塊成物１の内部からＣＯリッチな可燃性ガスが発生する。このガスが炭材内装塊成物１中に含まれる酸化鉄成分を内部から還元して還元鉄としＣＯ₂となるが、余剰のＣＯガスは炭材内装塊成物１の表面へ流出し、還元鉄の再酸化を防止している。特に還元工程の後半部では、還元が終了しつつあるので炭材内装塊成物１の表面へ流出するＣＯガスは減ってきている。このため、炭材内装塊成物や炉内雰囲気の温度を維持するために、炉上部にある蓄熱式バーナ２の燃焼側２ａを下部に向けて配設すると炭材内装塊成物１近傍がすぐに酸化性雰囲気となり再酸化してしまう。また、還元性ガスが蓄熱式バーナ２近傍まで近づき蓄熱式バーナ２の排気側２ｂに吸い込まれる恐れがある。このため本発明では、図５に示すように、蓄熱式バーナ２を炉床に対しほぼ水平もしくはやや上向きに配設する。これにより、蓄熱式バーナ２の燃焼側２ａの燃焼ガスによって炭材内装塊成物１近傍の雰囲気を乱すことがないので還元鉄の再酸化を起こさず、高金属化率を維持できるとともに、蓄熱式バーナ２の排気側２ｂに可燃性の還元ガスが吸い込まれることを防止できる。
【００４１】
また、本発明では、図６（ａ）に示すように、蓄熱式バーナ２の燃焼側２ａの燃焼ガスは酸素リッチな酸化性雰囲気とする。これによれば、還元工程で発生する可燃性の還元ガスを燃焼することができ、図６（ｂ）に示すように炭材内装塊成物１近傍は還元雰囲気に、蓄熱式バーナ２近傍は酸化性雰囲気に保つことができる。そして、炭材内装塊成物１が還元されてできる還元鉄の再酸化を防止し、蓄熱式バーナ２の排気側２ｂに可燃性の還元ガスが吸い込まれることを防止できるとともに、還元性ガスを炉内で有効に利用することによって炉内温度の維持が可能となり、エネルギーコストを低減できる。
【００４２】
なお、蓄熱式バーナ２の燃焼ガスを酸素リッチな酸化性雰囲気にするかわりに、図示はしないが、炭材内装塊成物１の上方でかつ蓄熱式バーナ２の下方へ空気または酸素等を吹き込むようにしてもよく、この場合も空気または酸素等の吹き込みは、炉床に対しほぼ水平もしくはやや上向きにすることが望ましい。これによれば、蓄熱式バーナ２の燃焼ガスを過剰に酸素リッチな酸化性雰囲気にし、燃焼を不安定にすることなく効果的に還元工程で発生する可燃性の還元ガスを燃焼することができ、酸化性ガスが炭材内装塊成物表面に直接当たることがなく、炭材内装塊成物近傍の雰囲気を乱すことがないので還元された炭材内装塊成物の再酸化を防止し、高金属化率を維持できる上記と同様な効果が得られる。
【００４３】
また、炭材内装塊成物１に還元工程の後半部に還元雰囲気を保つだけの炭素成分が含まれていない場合は、還元工程の後半部に還元鉄となった炭材内装塊成物１に向け炭化水素ガス（ＣｍＨｎ）を吹き込み還元鉄の再酸化を防止することもできる。この場合も蓄熱式バーナ２の燃焼ガスを酸素リッチな酸化性雰囲気とするか、空気または酸素を吹き込むことによって還元ガスとともに炭化水素ガスも燃焼させることができるので、上記と同様な効果が得られる。
【００４４】
またさらに、図２に示すように本発明では炉内排ガスを排出するガス排出部１２は還元工程の後半部より前に設置することが好ましい。例えば蓄熱式バーナ２を設置している還元工程後半部にガス排出部１２を設置した場合、蓄熱式バーナ２の燃焼ガスだけではなく炭材内装塊成物１近傍の可燃性ガスまでガス排出部１２に排出する流れができる。すると、蓄熱式バーナ２の排出側２ｂに可燃性ガスが吸い込まれる恐れがあるとともに、還元鉄の再酸化の恐れがある。しかし、ガス排出部１２を還元工程の後半部より前に設置すると、炭材内装塊成物１近傍の可燃性ガスは炭材内装塊成物１近傍を流れながらガス排出部１２に向かう。すると、ガス排出部１２から排出する前に十分に燃焼することができ有効活用が可能となる。さらにガス排出部１２近傍には蓄熱式バーナ２は設置されていないので蓄熱式バーナ２の排出側２ｂに可燃性ガスが吸い込まれることもなく、還元鉄の再酸化の恐れがない。
【００４５】
なお、還元工程の後半部では、前述した炭材内装塊成物１に含まれる揮発性物質（Ｚｎなど）は殆ど気化してしまっており、前記ガス排出部１２より排出されているので何ら問題はない。
【００４６】
また、本発明で用いられる蓄熱式バーナ２の設置数は還元鉄製造規模、処理量や蓄熱式バーナ２の熱出力によってきまり、設計条件によって適切な数とするものである。図１では蓄熱式バーナ２を還元工程の前半部に設置しており、図２では蓄熱式バーナ２を還元工程の後半部に設置しているが、図８に示すように還元工程の前半部、後半部の両方に設置してもよい。また、図１、２に示す蓄熱式バーナ２を還元工程の前半部のみ、後半部のみに設置した場合は、図示はしていないが、それぞれ還元工程後半部または前半部に蓄熱式バーナ以外の他の形式のバーナが使用される。さらに図８に示す還元工程の前半部、後半部の両方に蓄熱式バーナ２を設置した場合でも、蓄熱式バーナのみでは炉内温度維持ができない場合には蓄熱式バーナ以外の他の形式のバーナが使用される。
【００４７】
蓄熱式バーナを複数設置する場合、燃料と燃焼用酸素含有ガスとを蓄熱体を介し燃焼させる第一の蓄熱式バーナと、燃焼用酸素含有ガスのみを蓄熱体を介し前記還元炉内に吹込んで該還元炉内の可燃性ガスの一部を燃焼させる第二の蓄熱式バーナとを組み合わせ、第二の蓄熱式バーナを第一の蓄熱式バーナと炉床間に設置してもよい。この場合、炭材内装塊成物の加熱、還元反応が促進される。また、第一の蓄熱式バーナに替えて蓄熱式バーナ以外の他の形式のバーナを使用することができる。
【００４８】
なお、蓄熱式バーナ２の水平方向の設置角度は、燃焼側、排気側とも移動床の移動方向に垂直に設置すればよく、図４に示すように蓄熱式バーナ２の燃焼側、排気側が互いの方向に向けるように設置してもよい。
【００４９】
また、蓄熱式バーナとしては、燃料と空気、酸素、酸素富化した空気などの燃焼用酸素含有ガスとを蓄熱体を介し燃焼させるものだけではなく、燃焼用酸素含有ガスのみを蓄熱体を介し炉内に吹き込み、炉に装入される炭材内装塊成物から発生する炉内の可燃性ガスを利用して燃焼するタイプのものでもよい。
【００５０】
次に、本発明に係わる第３の実施の形態について説明する。本発明では蓄熱式バーナ２の蓄熱体に鉄鉱石ペレット等の鉄鉱石塊成物または還元鉄を使用する。鉄鉱石ペレットや還元鉄には炭材や揮発性成分が含まれていないため高温のガスで加熱されても還元性ガスや揮発性成分は発生しないので、蓄熱体に使用しても何ら問題ない。また、鉄鉱石ペレットや還元鉄はセラミックス等の通常の蓄熱体材料に比較して低コストであり、蓄熱体として使用ずみの鉄鉱石ペレットや還元鉄を、鉄源として本発明の還元鉄製造設備や高炉などで再利用することができ、さらに鉄鉱石ペレットや還元鉄に揮発性成分が付着したとしても、本発明の還元鉄製造設備の原料として用いれば効果的に揮発性成分を除去できるだけでなく、蓄熱体の取り替えにかかるコストを低減することができる。
【００５１】
ここで、蓄熱体として使用されるのは、上記鉄鉱石をペレット状に成形した鉄鉱石ペレット及び還元鉄製造方法で製造された還元鉄だけではなく、この還元鉄を酸化させたものや製鉄所で用いられる焼成（焼結）された鉄鉱石ペレットを用いれば、入手が容易であるとともに安価である。また、焼成または酸化されているので、形状が安定しており、その性質が安定しているので取り扱いが容易である。
【００５２】
なお、本発明で用いられる酸化鉄含有材料としては、鉄鉱石、酸化鉄精鉱や製鉄所等で発生する鉄分を含んだダスト、スラッジ、スケール等の廃材が使用できる。また、炭素含有還元材料としては、石炭、コークス、チャー、オイルコークス等が使用できる。
【００５３】
また、上記実施の形態では酸化鉄含有材料を例に説明したが、酸化鉄の一部または全部をマンガン（Ｍｎ）、ニッケル（Ｎｉ）、クロム（Ｃｒ）等の非鉄金属の酸化物としても同様に還元でき、蓄熱式バーナも問題なく使用することができる。
【００５４】
【実施例】
以下に、図８に示す実施例を挙げて本発明をさらに詳細に説明する。使用した炭材内装塊成物の組成を表１に示す。表１に示す組成の炭材内装塊成物を加熱したときの前記塊成物の表面温度、揮発性物質の代表である亜鉛の脱Ｚｎ率と、その発生量比を図３に示す。脱Ｚｎ率は原料中のＺｎ量を１として求め、発生量比は１分後の発生量を１とし、それ以降の時間における発生量を発生量比として求めた。
【００５５】
【表１】

【００５６】
代表的な揮発性元素である亜鉛は、原料中では主として酸化亜鉛として存在するが、加熱によってＺｎＯ＋ＣＯ→Ｚｎ＋ＣＯ₂の反応が起こりＺｎが気化し、蓄熱体などに付着・堆積する。特に、約１２００〜１２５０℃以上では図３に示すように急激に揮発する。したがって、本発明では蓄熱式バーナを炭材内装塊成物の表面温度が１２５０℃以下の位置に設置し蓄熱体への揮発性物質の付着を防止している。そして１２５０℃以下である工程の後方にガス排出部１２を設けて、炭材内装塊成物１の原料から発生する亜鉛等の揮発性物質をガス排出部１２から炉外に排出するようにしている。
【００５７】
還元工程の後半部では、前記塊成物の温度は高いものの、塊成物中の亜鉛はほぼ揮発している。また、本発明では、蓄熱式バーナの設置位置の還元工程の前半部にガス排出部１２を設けているので還元工程の前半部で発生した揮発性物質を還元工程の後半部まで持ち込むのを防止することができる。
【００５８】
本実施例では、図９に示すように、蓄熱式バーナを設置することによって、燃料原単位を約１．２６ＧＪ／ｔ−ＤＲＩ（還元鉄１ｔ当たり１．２６ＧＪ（０．３Ｇｃａｌ））低減することができた。なお、燃料原単位は生産規模（炉の大きさと生産量）によって変化し、本実施例では、外径２１．５ｍ、内径１４．０ｍの回転炉床炉を用い、還元鉄の生産量２０ｔ／ｈという実施条件で運転した。
【００５９】
蓄熱体として使用した鉄鉱石ペレットの原料組成の一例を表２に示す。直径５〜１５ｍｍの鉄鉱石ペレットを篩にかけ、直径６〜９ｍｍのものを蓄熱体として使用した。鉄鉱石ペレットは、従来使用されているアルミナ質などの蓄熱体と同様な性能を有していることが確認でき、使用には問題がなかった。使用後の鉄鉱石ペレットは鉄源として本実施例の還元炉で再利用したが、特に問題はなかった。なお、鉄鉱石ペレットは鉄の酸化物Ｆｅ₂Ｏ₃とＦｅ₃Ｏ₄が９０〜９５％であるため、ＳｉＯ₂−ＦｅＯ−Ａｌ₂Ｏ₃系の低融点化合物をほとんど生成せず、蓄熱体に使用しても表面が溶融しガス通気性や溶着などの蓄熱体の劣化が抑制される。
【００６０】
【表２】

【００６１】
【発明の効果】
本発明では、蓄熱式バーナを塊成物装入部からガス排出部の間の揮発性成分があまり揮発しない還元工程前半の位置に設置することで、揮発性成分による蓄熱体の劣化がなく、ダスト捕集装置が不要となり、蓄熱式バーナ設置スペースが小さくてすむとともに、イニシャルコストが増大することがない。
【００６２】
本発明では、蓄熱式バーナとして、燃料と燃焼用酸素含有ガスとを蓄熱体を介し燃焼させる第一の蓄熱式バーナと、燃焼用酸素含有ガスのみを蓄熱体を介し前記還元炉内に吹込んで該還元炉内の可燃性ガスの一部を燃焼させる第二の蓄熱式バーナとを組み合わせ、第二の蓄熱式バーナを第一の蓄熱式バーナと炉床間に設置することで、炭材内装塊成物の内部から発生する還元性ガスを、該炭材内装塊成物の近傍で効率的に燃焼させることができる。このため、該炭材内装塊成物への伝熱効果が向上し、該炭材内装塊成物の加熱、還元反応が促進される。したがって、還元鉄製造の生産性が向上する一方、バーナ排ガス量の低減と燃料原単位の向上を図ることができる。
【００６３】
また、蓄熱式バーナをガス排出部から還元鉄排出部の間の還元工程後半の位置に設置し、蓄熱式バーナ近傍と炭材内装塊成物近傍の雰囲気をそれぞれ酸化性雰囲気と還元性雰囲気に保つことで、不活性ガスによる置換のための装置が不要となり蓄熱式バーナ設置スペースが小さくてすむとともに、蓄熱式バーナを排気側から燃焼側へ切り替える時間が短くてすむ。
【００６４】
さらに、蓄熱式バーナが、移動床型還元炉の上部に設置され、前記移動床型還元炉の炉床に対してほぼ水平もしくはやや上向きに配置されているので、酸化性ガスが炭材内装塊成物表面に直接当たることがなく、炭材内装塊成物近傍の雰囲気を乱すことがないので還元された炭材内装塊成物の再酸化を防止し、高金属化率を維持できる。
【００６５】
またさらに、本発明では蓄熱体として鉄鉱石ペレットまたは還元鉄を使用するため、安価であり、たとえ揮発性成分やダスト成分が付着したとしても、廃棄することなく、本発明の還元鉄製造設備の原材料として使用できるためランニングコストが増大することもないとともに、使用済みの蓄熱体を廃棄することによる環境悪化等の問題がない。またさらに、本発明は還元鉄だけではなく非鉄金属の製造にも蓄熱式バーナを使用できる。
【図面の簡単な説明】
【図１】本発明の蓄熱式バーナを還元工程の前半部に設置した場合を示す還元鉄製造設備の概念図である。
【図２】本発明の蓄熱式バーナを還元工程の後半部に設置した場合を示す還元鉄製造設備の概念図である。
【図３】炭材内装塊成物を加熱したときの表面温度、脱亜鉛率、亜鉛発生量比示す図である。
【図４】蓄熱式バーナの設置例を示す図である。
【図５】蓄熱式バーナの設置位置を説明する図であり、（ａ）は炉内での炭材内装塊成物と蓄熱式バーナの位置関係を示し、（ｂ）は（ａ）のＡ−Ａ線断面図である。
【図６】蓄熱式バーナの設置位置における蓄熱式バーナ近傍及び炭材内装塊成物近傍の雰囲気を示す概念図であり、（ａ）は炉の断面図を示す概念図であり、（ｂ）は酸素ガス雰囲気と還元性ガス雰囲気の分布を示す図である。
【図７】本発明の蓄熱式バーナを示す図であり、（ａ）は吸排気部２ａが燃焼側で吸排気部２ｂが排気側である状態を示し、（ｂ）は（ａ）の逆の吸排気部２ｂが燃焼側で吸排気部２ａが排気側である状態を示す図である。
【図８】本発明の蓄熱式バーナを還元工程の前半部及び後半部の両方に設置した場合を示す還元鉄製造設備の概念図である。
【図９】蓄熱式バーナの使用の有無による燃料原単位の差を示す図である。
【符号の説明】
１…炭材内装塊成物、２…蓄熱式バーナ、２ａ、２ｂ…吸排気部、３…燃料配管、４ａ、４ｂ…排ガス配管、５ａ、５ｂ…燃料切替弁、６ａ、６ｂ…排ガス切替弁、７ａ、７ｂ…蓄熱体、８…炉床、１０…塊成物装入部、１１…還元鉄排出部、１２…ガス排出部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reduced iron production facility and a reduced iron made by introducing a carbonaceous material-containing agglomerate composed of an iron oxide-containing material and a carbonaceous material-containing reduced material into a moving bed type reduction furnace and producing reduced iron by heating and reducing. The present invention relates to a method, and also relates to a non-ferrous metal production facility and a non-ferrous metal production method.
[0002]
[Prior art]
The regenerative burner has two intake / exhaust parts, one of the intake / exhaust parts is used as the combustion side by burning fuel and combustion air, and the other intake / exhaust part is heated by the burner and is used for atmospheric gas, combustion gas, etc. It is used as an exhaust side for inhaling high temperature gas and exhausting it outside. Each of these intake / exhaust parts is provided with a heat storage body, which stores heat when the high-temperature gas is sucked in the exhaust-side intake / exhaust part and is used as a burner in the combustion-side intake / exhaust part. Preheat fuel and combustion air with the heat stored in Then, by switching between the combustion side and the exhaust side, exhaust gas, which is a high-temperature gas, is used to increase thermal efficiency. For this reason, conventionally, a regenerative burner has been used for industrial heating furnaces such as metal heating furnaces and heat treatment furnaces, or for drying and preheating refractories in a ladle.
[0003]
However, in general, if the high-temperature gas in the furnace contains a large amount of dust or volatile substances, there is concern about premature deterioration of the heat storage body or contamination of the heat storage body with volatile substances. It was considered difficult.
[0004]
Also, if the inside of the furnace is in a reducing atmosphere with flammable gas, if the air is taken in by the intake / exhaust part on the exhaust side of the regenerative burner as it is, the heat storage body is poisoned or combustible by inhaling the flammable gas Since the gas is discharged out of the furnace as it is, there are problems such as an environmental problem.
[0005]
For this reason, in Japanese Patent Laid-Open No. 9-126443, in order to collect iron oxide as a dust component, a collection device is provided between the furnace and the heat storage body, and furthermore, a material having high corrosion resistance such as ceramics as the heat storage body. What uses is disclosed.
[0006]
Japanese Patent Laid-Open No. 7-103433 discloses an arrangement in which explosion is prevented by replacing the exhaust side piping and the heat storage type burner with an inert gas before switching from the exhaust side to the combustion side. .
[0007]
[Problems to be solved by the invention]
However, replacement with a collecting device or an inert gas requires a device for this purpose, which complicates the structure of the regenerative burner, increases the installation space for the regenerative burner, and increases the initial cost. Further, every time the regenerative burner is switched from the exhaust side to the combustion side, it is necessary to remove dust or replace with an inert gas, which causes a problem that switching takes time.
[0008]
In addition, when a highly corrosion-resistant material such as ceramics is used as the heat storage body, it is expensive although it has corrosion resistance. If there are many volatile components and dust components in the furnace, volatile components and dust components adhere to it. As a result, frequent replacement is forced to increase running costs, and there are problems such as environmental degradation due to disposal of used heat storage bodies.
[0009]
In particular, in a reduced iron production facility in which a carbonaceous material-containing agglomerate composed of an iron oxide-containing material and a carbon-containing reduced material is charged into a moving bed type reduction furnace and heated to reduce to produce reduced iron, Iron oxide or the like becomes powder and tends to be present in the furnace as dust, and a material containing a large amount of volatile components may be used as a raw material. Furthermore, in order to reduce, it is necessary to make the atmosphere in the furnace a reducing atmosphere, and in the reduced iron production facility, a flammable gas such as flammable gas or natural gas generated from the carbon-containing reducing material in the raw material is blown into this. This makes it a reducing atmosphere. For this reason, a large amount of volatile components easily volatilize in the first half of the reduction process in which heating is started, and in the second half of the reduction process, reoxidation is prevented and a sufficient reducing atmosphere is maintained to maintain a high metalization rate. A heat storage burner was not used because it was necessary.
[0010]
An object of this invention is to solve the above problems, and to provide the reduced iron manufacturing equipment using a thermal storage type burner.
[0011]
[Means for Solving the Problems]
As a means for solving the above-mentioned problems, claim 1 of the present invention is a method in which a carbonaceous material-containing agglomerate comprising an iron oxide-containing material and a carbon-containing reducing material is charged into a moving bed type reduction furnace and heated and reduced. In the reduced iron production facility for producing reduced iron, the moving bed type reduction furnace includes an agglomerate charging part for charging the carbonaceous material-incorporated agglomerate, and a reduced iron discharging part for discharging the reduced iron. A gas discharge unit for discharging the exhaust gas in the furnace during the reduction process from the agglomerate charging unit to the reduced iron discharge unit; A heat storage burner as a heating source of the moving bed type reduction furnace, which is the latter half of the reduction process and is provided between the gas discharge unit and the reduced iron discharge unit, and the heat storage burner includes the moving bed It is installed in the upper part of the type reduction furnace, and is arranged almost horizontally or slightly upward with respect to the hearth of the moving bed type reduction furnace. This is a facility for producing reduced iron.
[0012]
Claim 2 of the present invention provides further, The first half of the reduction step, between the agglomerate charging part and the gas discharging part There is also a regenerative burner It is the reduced iron manufacturing facility characterized by being equipped.
[0013]
According to a third aspect of the present invention, the regenerative burner in the first half of the reduction step is installed at a position where the surface temperature of the carbonaceous material-incorporated agglomerate is 1250 ° C. or less, and the gas discharge part is The reduced iron production facility is characterized in that it is installed at a position behind a region where the surface temperature of the carbonaceous material agglomerate is 1250 ° C. or lower.
[0014]
According to a fourth aspect of the present invention, the regenerative burner is a second half of the reduction process, and is provided between the gas discharge unit and the reduced iron discharge unit, and the regenerative burner is the moving unit. It is a reduced iron manufacturing facility characterized in that it is installed at the upper part of a floor type reduction furnace and is arranged substantially horizontally or slightly upward with respect to the hearth of the moving bed type reduction furnace.
[0015]
Claim 5 of the present invention is the reduced iron characterized in that the combustion gas of the regenerative burner in the latter half of the reduction step is an oxidizing atmosphere, and the atmosphere covering the carbonaceous material agglomerates is a reducing atmosphere. Manufacturing equipment.
[0016]
[0017]
Claims of the invention 5 Said In the first half of the reduction process A regenerative burner is a first regenerative burner that burns fuel and combustion oxygen-containing gas through a heat storage body, and only the combustion oxygen-containing gas is blown into the reduction furnace through the heat storage body. Combined with a second regenerative burner that burns part of the combustible gas ,in front It is reduced iron manufacturing equipment characterized by installing the 2nd regenerative burner below the installation position of the 1st regenerative burner.
[0018]
Claims of the invention 6 Said In the first half of the reduction process The regenerative burner is a regenerative burner in which only a combustion oxygen-containing gas is blown into the reduction furnace through a heat storage body to burn a part of the combustible gas in the reduction furnace, and further contains fuel and combustion oxygen Burn with gas , Other types of heat storage type burner A reduced iron production facility equipped with a burner ,in front It is reduced iron manufacturing equipment characterized by arranging a thermal storage type burner below the installation position of the burner.
[0019]
Claims of the invention 7 Is , Storage The heat storage body of the thermal burner is reduced iron production equipment characterized in that it is reduced iron or iron ore agglomerates produced at the reduced iron production equipment.
[0020]
Claims of the invention 8 Is a non-ferrous metal production facility characterized in that a part or all of the iron oxide-containing material is a non-ferrous metal oxide.
[0021]
Claims of the invention 9 In the method for producing reduced iron, the carbonaceous material-containing agglomerate comprising an iron oxide-containing material and a carbon-containing reducing material is charged into a moving bed type reduction furnace, and reduced iron is produced by heating and reducing in the furnace. Exhaust gas in the furnace is discharged in the first half of the reduction process from charging to discharging of the carbonaceous material agglomerate, and the carbonaceous material agglomerate is installed in the upper part of the moving bed type reduction furnace, Heated by a regenerative burner arranged almost horizontally or slightly upward with respect to the hearth of the moving bed type reduction furnace, and the combustion gas of the regenerative burner is made an oxidizing atmosphere so that the vicinity of the regenerative burner Manufacturing reduced iron while maintaining an atmosphere covering the vicinity of the carbonaceous material-incorporated agglomerate while making the atmosphere an oxidizing atmosphere and burning the reducing gas generated from the inside of the carbonaceous material-incorporated agglomerate This is a method for producing reduced iron.
[0022]
Claims of the invention 10 The regenerative burner is a first regenerative burner that burns fuel and combustion oxygen-containing gas through a heat storage body, and only the combustion oxygen-containing gas is blown into the reduction furnace through the heat storage body. Combined with a second regenerative burner that burns a part of the combustible gas in the reduction furnace, and between the agglomerate charging portion and the first half of the reduction step, the second This is a method for producing reduced iron, characterized in that the heat storage burner is installed below the installation position of the first heat storage burner.
[0023]
Claims of the invention 11 The regenerative burner is a regenerative burner in which only a combustion oxygen-containing gas is blown into the reduction furnace through a heat storage body, and a part of the combustible gas in the reduction furnace is burned, and fuel and combustion Burning oxygen-containing gas , Other types of heat storage type burner Manufacture of reduced iron with burner Method In the method for producing reduced iron, the regenerative burner is disposed below the burner installation position between the agglomerate charging section and the first half of the reduction step.
[0024]
Claims of the invention 12 Is a reduced iron production method, wherein the heat storage body of the regenerative burner is reduced iron or iron ore agglomerate produced by the reduced iron production method.
[0025]
Claims of the invention 13 Is a non-ferrous metal production method, wherein a part or all of the iron oxide-containing material is a non-ferrous metal oxide.
[0026]
Claim 1, 9 According to the invention, it is possible to use a regenerative burner in reduced iron production equipment that has not been used in the past, and it is possible to effectively use the exhaust gas in the furnace, so that the thermal efficiency can be increased and the cost can be reduced.
[0027]
Claim 2 Three According to the invention, by installing the regenerative burner in the first half of the reduction process where the volatile components between the agglomerate charging section and the gas exhaust section do not volatilize so much, there is no deterioration of the regenerator due to the volatile components. In addition, the dust collecting device is not required, the installation space for the heat storage type burner is small, and the initial cost is not increased.
[0028]
And claims 1, 4, 9 According to the invention, the regenerative burner is installed at a position in the latter half of the reduction process between the gas discharge part and the reduced iron discharge part, and the atmosphere in the vicinity of the regenerative burner and in the vicinity of the carbonaceous material interior agglomerate is an oxidizing atmosphere. Maintaining the reducing atmosphere eliminates the need for a device for replacement with an inert gas, reduces the installation space for the regenerative burner, and shortens the time for switching the regenerative burner from the exhaust side to the combustion side. Furthermore, it is installed in the upper part of the moving bed type reduction furnace, and is arranged almost horizontally or slightly upward with respect to the hearth of the moving bed type reduction furnace, so that the oxidizing gas is directly applied to the surface of the carbonaceous material agglomerate. Since it does not hit and does not disturb the atmosphere in the vicinity of the carbonaceous material agglomerate, it can prevent reoxidation of the reduced carbonaceous material agglomerate and maintain a high metalization rate.
[0029]

Claim

5, 10 According to the invention, the second heat storage type burner is installed between the first heat storage type burner and the hearth so that the reducing gas generated from the inside of the carbonaceous material interior can be reduced. Can be efficiently burned in the vicinity. For this reason, the heat transfer effect to this carbon material interior agglomerated material improves, and the heating and reduction reaction of this carbon material interior agglomerated material are promoted. Therefore, productivity of reduced iron production can be improved, while the burner exhaust gas amount can be reduced and the fuel consumption rate can be improved.
[0030]
According to the inventions of

claims

6 and 11, Instead of the first regenerative burner, other types of burners other than the regenerative burner can be used. , By installing the regenerative burner between the burner and the hearth, the reducing gas generated from the inside of the carbonaceous material agglomerated material can be efficiently burned in the vicinity of the carbonaceous material agglomerated material.
[0031]
And further claims 7, 12 According to the invention, since iron ore agglomerates or reduced iron is used as a heat storage body, it is inexpensive, and even if volatile components or dust components adhere to it, the reduced iron production of the present invention can be performed without being discarded. Since it can be used as a raw material for equipment, running costs do not increase, and there are no problems such as deterioration of the environment due to disposal of used heat storage elements.
[0032]
And claims 8, 13 According to the invention, the regenerative burner can be used not only for reducing iron but also for producing non-ferrous metals.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
In the reduced iron production facility of the present invention, a regenerative burner as shown in FIG. 7 is used. The regenerative burner 2 has two intake / exhaust portions (2a, 2b). First, as in the state of FIG. 7A, in one intake / exhaust section 2a, the fuel and combustion air are burned from the fuel pipe 3 through the fuel switching valve 5a through the heat accumulator 7a and burned. Use as In the other intake / exhaust part 2b, high-temperature gas such as atmospheric gas or combustion gas heated on the combustion side of the intake / exhaust part 2a is sucked and exhausted from the exhaust gas pipe 4b to the outside through the heat storage body 7b through the exhaust gas switching valve 6b. Is done. At this time, the sensible heat of the high-temperature gas is stored in the heat storage body 7b. In this state, the fuel switching valve 5b and the exhaust gas switching valve 6a are closed. Then, when a certain time has elapsed, the state is switched to the state shown in FIG. 7B, and in the other intake / exhaust portion 2b, fuel and combustion air are burned from the fuel pipe 3 to the fuel switching valve 5b through the heat storage body 7b. By using as a combustion side. In one intake / exhaust section 2a, a high-temperature gas such as atmospheric gas or combustion gas heated on the combustion side of the intake / exhaust section 2b is sucked into the exhaust gas switching valve 6a via the heat accumulator 7a and is discharged from the exhaust gas pipe 4a to the outside. Exhausted. At this time, the fuel and combustion air are heated by the heat stored in the heat storage body 7b, and the sensible heat of the high-temperature gas is stored in the heat storage body 7a. In this state, the fuel switching valve 5a and the exhaust gas switching valve 6b are closed. Then, after a certain time has elapsed, the state is switched again to the state of FIG. By repeating this, the sensible heat of the high temperature gas is used to increase the thermal efficiency.
[0034]
Next, FIG. 1 shows a first embodiment according to the present invention using the heat storage burner. In the reduced iron production facility of the present invention, a rotary hearth furnace is used as the moving hearth furnace. The iron oxide-containing material and the carbon-containing reducing material as raw materials are mixed in advance, and a binder is added as necessary to form a spherical pellet or briquette-shaped carbon material-containing agglomerate 1. This carbonaceous material-incorporated agglomerate 1 is charged from the agglomerate insertion portion 10 and is leveled by a leveling machine (not shown) as required. And it reduces in a reduction | restoration process while moving to the reduced iron discharge part 11 from the agglomerate insertion part 10 on the floor furnace 8, and becomes reduced iron.
[0035]
The inside of the furnace is heated from about 1350 ° C. to about 1400 ° C. by the combustion side intake / exhaust part of the regenerative burner 2 installed between the agglomerate insertion part 10 and the reduced iron discharge part 11, and the hearth is 1 While rotating, it is heated and reduced so as to have a predetermined metallization rate, and is discharged as reduced iron from the reduced iron discharge section 11 to the outside of the furnace.
[0036]
The exhaust gas in the furnace is discharged from a gas discharge part 12 provided between the agglomerate insertion part 10 and the reduced iron discharge part 11 and also from the exhaust side intake / exhaust part of the regenerative burner 2.
[0037]
In this way, by using the regenerative burner 2, the combustion and exhaust (heat storage) are alternately repeated with the intake and exhaust portions (2a, 2b) of the regenerative burner 2 as the combustion side intake and exhaust portions and the exhaust side intake and exhaust portions. Thus, the fuel efficiency of the burner and the combustion air are preheated through the heat storage body, so that the thermal efficiency is improved.
[0038]
When the carbonaceous material-containing agglomerate 1 is charged from the charging device, the temperature is rapidly increased by the high-temperature furnace gas. At this time, the volatile components contained in the carbonaceous material-incorporated agglomerate 1 are volatilized. As shown in FIG. 3, when the surface temperature of the carbonaceous material agglomerate 1 exceeds about 1250 ° C., zinc (which is a representative volatile substance contained in the raw material of the carbonaceous material agglomerate 1 ( Zn) starts to volatilize rapidly. If the gas containing this volatile substance is exhausted from the exhaust side of the regenerative burner 2, volatile substances adhere to the regenerator, causing clogging and lowering the heat storage performance of the regenerator. Therefore, the regenerative burner 2 used in the present invention is the first half of the reduction process, and is installed in a region where volatile substances are less volatilized than the carbonaceous material agglomerates, and the surface temperature is 1250 ° C. or lower. It is preferable to install in a certain area.
[0039]
And in this invention, it is good to provide the gas exhaust part 12 in the back of the area | region where the surface temperature of the carbonaceous material agglomerate 1 which has installed the thermal storage burner 2 is 1250 degrees C or less. By providing the gas discharge unit 12 at this position, the gas discharge unit can be used without causing the volatile substances volatilized from the carbonaceous material agglomerate 1 whose surface temperature has been raised to 1250 ° C. or more to flow before the generation site. Therefore, the regenerative burner 2 installed in the first half of the reduction process does not discharge the gas containing volatiles. Therefore, it does not adhere to the heat storage body of the heat storage burner 2, and the heat storage body is not deteriorated or the heat storage body is clogged and the heat storage performance is not lowered. Further, by directing the gas flow in the furnace to the gas discharge unit 12, dust can be prevented from flowing into the heat storage burner 2, and the heat storage burner 2 does not suck in dust, and heat storage due to dust adhering to the heat storage body. It does not cause deterioration of the body or clogging of the heat accumulator, resulting in deterioration of the heat accumulating performance.
[0040]
Next, a second embodiment according to the present invention is shown in FIG. In this invention, as shown in FIG. 2, the thermal storage type burner 2 is installed in the latter half part of a reduction process. When the carbonaceous material agglomerate 1 is reduced, CO-rich combustible gas is generated from the inside of the carbonaceous material agglomerated material 1. This gas reduces the iron oxide component contained in the carbonaceous material agglomerate 1 from the inside to form reduced iron and CO. ₂ However, surplus CO gas flows out to the surface of the carbonaceous material-containing agglomerate 1 to prevent reoxidation of the reduced iron. In particular, in the latter half of the reduction process, since the reduction is being completed, the CO gas flowing out to the surface of the carbonaceous material-containing agglomerate 1 is decreasing. For this reason, when the combustion side 2a of the regenerative burner 2 in the upper part of the furnace is arranged facing downward to maintain the temperature of the carbonaceous material agglomerate and the atmosphere in the furnace, It immediately becomes an oxidizing atmosphere and re-oxidizes. Further, the reducing gas may approach the vicinity of the regenerative burner 2 and be sucked into the exhaust side 2b of the regenerative burner 2. For this reason, in this invention, as shown in FIG. 5, the thermal storage type burner 2 is arrange | positioned substantially horizontal with respect to a hearth or slightly upwards. As a result, the combustion gas on the combustion side 2a of the regenerative burner 2 does not disturb the atmosphere in the vicinity of the carbonaceous material agglomerate 1 so that reoxidation of reduced iron does not occur and a high metallization rate can be maintained and heat storage The combustible reducing gas can be prevented from being sucked into the exhaust side 2b of the type burner 2.
[0041]
Moreover, in this invention, as shown to Fig.6 (a), the combustion gas of the combustion side 2a of the thermal storage type burner 2 is made into oxygen-rich oxidizing atmosphere. According to this, combustible reducing gas generated in the reduction process can be combusted. As shown in FIG. 6B, the vicinity of the carbonaceous material-incorporated agglomerate 1 is in a reducing atmosphere, and the vicinity of the regenerative burner 2 is An oxidizing atmosphere can be maintained. And it can prevent reoxidation of the reduced iron which carbonaceous material agglomerate 1 is reduced, can prevent inflammable reducing gas from being sucked into exhaust side 2b of regenerative burner 2, and can also reduce reducing gas. By effectively using the inside of the furnace, it is possible to maintain the temperature in the furnace and reduce the energy cost.
[0042]
In addition, instead of making the combustion gas of the regenerative burner 2 into an oxygen-rich oxidizing atmosphere, air or oxygen is blown above the carbonaceous material agglomerate 1 and below the regenerative burner 2 (not shown). In this case as well, it is desirable that the blowing of air, oxygen, or the like is substantially horizontal or slightly upward with respect to the hearth. According to this, the combustion gas of the regenerative burner 2 can be made an excessively oxygen-rich oxidizing atmosphere, and the combustible reducing gas generated in the reduction process can be effectively burned without destabilizing the combustion. , Because the oxidizing gas does not directly hit the surface of the carbonaceous material agglomerate and does not disturb the atmosphere in the vicinity of the carbonaceous material agglomerate, preventing reoxidation of the reduced carbonaceous material agglomerate, An effect similar to the above that can maintain a high metallization rate is obtained.
[0043]
Moreover, when the carbon material interior agglomerate 1 does not contain a carbon component sufficient to maintain a reducing atmosphere in the latter half of the reduction process, the carbon material interior agglomerate 1 that has become reduced iron in the latter half of the reduction process. It is possible to prevent reoxidation of reduced iron by blowing hydrocarbon gas (CmHn) toward the bottom. Also in this case, the combustion gas of the regenerative burner 2 is made an oxygen-rich oxidizing atmosphere, or the hydrocarbon gas can be burned together with the reducing gas by blowing air or oxygen, so the same effect as described above can be obtained. .
[0044]
Furthermore, as shown in FIG. 2, in the present invention, it is preferable that the gas discharge unit 12 for discharging the exhaust gas in the furnace is installed before the latter half of the reduction process. For example, when the gas discharge unit 12 is installed in the latter half of the reduction process in which the regenerative burner 2 is installed, not only the combustion gas of the regenerative burner 2 but also the combustible gas in the vicinity of the carbonaceous material agglomerate 1 12 can be discharged. Then, combustible gas may be sucked into the discharge side 2b of the regenerative burner 2 and reoxidation of reduced iron may occur. However, if the gas discharge part 12 is installed before the latter half part of the reduction process, the combustible gas in the vicinity of the carbonaceous material agglomerate 1 flows toward the gas discharge part 12 while flowing in the vicinity of the carbonaceous material agglomerate 1. Then, it can combust sufficiently before discharging from the gas discharge unit 12 and can be effectively used. Further, since the regenerative burner 2 is not installed in the vicinity of the gas discharge unit 12, the combustible gas is not sucked into the discharge side 2b of the regenerative burner 2, and there is no fear of reoxidation of reduced iron.
[0045]
In the second half of the reduction process, volatile substances (Zn and the like) contained in the carbonaceous material agglomerate 1 described above are almost vaporized and are discharged from the gas discharge unit 12, so there is no problem. There is no.
[0046]
The number of regenerative burners 2 used in the present invention is determined by the reduced iron production scale, the amount of processing and the heat output of the regenerative burner 2, and is an appropriate number depending on the design conditions. In FIG. 1, the regenerative burner 2 is installed in the first half of the reduction process, and in FIG. 2, the regenerative burner 2 is installed in the second half of the reduction process, but as shown in FIG. It may be installed in both of the latter half. In addition, when the regenerative burner 2 shown in FIGS. 1 and 2 is installed only in the first half of the reduction process and only in the second half, it is not shown in the figure. Other types of burners are used. Furthermore, even when the regenerative burner 2 is installed in both the first half and the second half of the reduction process shown in FIG. 8, if the temperature inside the furnace cannot be maintained only by the regenerative burner, other types of burners other than the regenerative burner are used. Is used.
[0047]
When installing a plurality of regenerative burners, the first regenerative burner that burns fuel and combustion oxygen-containing gas through the heat storage body, and only the combustion oxygen-containing gas is blown into the reduction furnace through the heat storage body. A second regenerative burner that combusts a part of the combustible gas in the reduction furnace may be combined, and the second regenerative burner may be installed between the first regenerative burner and the hearth. In this case, heating and reduction reaction of the carbonaceous material agglomerate are promoted. Moreover, it can replace with a 1st heat storage type burner, and can use the burner of types other than a heat storage type burner.
[0048]
The horizontal installation angle of the regenerative burner 2 may be set perpendicular to the moving direction of the moving bed on both the combustion side and the exhaust side, and the combustion side and the exhaust side of the regenerative burner 2 are mutually connected as shown in FIG. You may install so that it may face in the direction.
[0049]
In addition, the regenerative burner is not only one that burns fuel and combustion oxygen-containing gas such as air, oxygen, and oxygen-enriched air through the heat storage body, but only combustion oxygen-containing gas through the heat storage body. It may be of a type that burns using a combustible gas in the furnace generated from a carbonaceous material agglomerate that is blown into the furnace and charged into the furnace.
[0050]
Next, a third embodiment according to the present invention will be described. In the present invention, iron ore agglomerates such as iron ore pellets or reduced iron are used for the heat storage body of the heat storage burner 2. Since iron ore pellets and reduced iron do not contain carbonaceous materials or volatile components, reducing gases and volatile components are not generated even when heated with high-temperature gas. . In addition, iron ore pellets and reduced iron are less expensive than ordinary heat storage materials such as ceramics, and the iron ore pellets and reduced iron used as heat storage are used as iron sources for the reduced iron production facility of the present invention. Even if volatile components adhere to iron ore pellets or reduced iron, they can be effectively removed if used as raw materials for the reduced iron production facility of the present invention. In addition, the cost required for replacing the heat storage body can be reduced.
[0051]
Here, not only the iron ore pellets obtained by forming the iron ore into pellets and the reduced iron produced by the reduced iron production method, but also the oxidized iron or steelworks are used as the heat storage body. If the baked (sintered) iron ore pellets used in the above are used, it is easy to obtain and inexpensive. Moreover, since it is baked or oxidized, its shape is stable, and its properties are stable, so it is easy to handle.
[0052]
As the iron oxide-containing material used in the present invention, waste materials such as dust, sludge, and scale containing iron generated in iron ore, iron oxide concentrate, steelworks, etc. can be used. Further, as the carbon-containing reducing material, coal, coke, char, oil coke and the like can be used.
[0053]
In the above-described embodiment, the iron oxide-containing material has been described as an example. However, a part or all of the iron oxide may be the same as a non-ferrous metal oxide such as manganese (Mn), nickel (Ni), or chromium (Cr). The regenerative burner can be used without any problem.
[0054]
【Example】
Hereinafter, the present invention will be described in more detail with reference to the embodiment shown in FIG. Table 1 shows the composition of the carbonaceous material agglomerates used. FIG. 3 shows the surface temperature of the agglomerate when the carbonaceous material-incorporated agglomerate having the composition shown in Table 1 is heated, the Zn removal rate of zinc, which is a representative volatile substance, and the ratio of the generated amount. The Zn removal rate was determined by taking the amount of Zn in the raw material as 1, and the generation amount ratio was determined by taking the generation amount after 1 minute as 1, and the generation amount after that time as the generation amount ratio.
[0055]
[Table 1]

[0056]
Zinc, which is a typical volatile element, exists mainly as zinc oxide in the raw material, but ZnO + CO → Zn + CO by heating. ₂ This occurs and Zn vaporizes and adheres to and accumulates on the heat storage body. In particular, at about 1200 to 1250 ° C. or more, it volatilizes rapidly as shown in FIG. Therefore, in the present invention, the regenerative burner is installed at a position where the surface temperature of the carbonaceous material agglomerate is 1250 ° C. or less to prevent the attachment of volatile substances to the regenerator. And the gas discharge part 12 is provided behind the process which is 1250 degrees C or less, and volatile substances, such as zinc generated from the raw material of the carbonaceous material agglomerate 1, are discharged from the gas discharge part 12 to the outside of the furnace. Yes.
[0057]
In the latter half of the reduction process, although the temperature of the agglomerate is high, zinc in the agglomerate is almost volatilized. Further, in the present invention, since the gas discharge unit 12 is provided in the first half of the reduction process at the installation position of the regenerative burner, the volatile substances generated in the first half of the reduction process are prevented from being brought into the second half of the reduction process. can do.
[0058]
In this embodiment, as shown in FIG. 9, by installing a heat storage type burner, the fuel intensity is reduced by about 1.26 GJ / t-DRI (1.26 GJ (0.3 Gcal) per ton of reduced iron). I was able to. The fuel consumption rate varies depending on the production scale (furnace size and production amount). In this embodiment, a rotary hearth furnace having an outer diameter of 21.5 m and an inner diameter of 14.0 m is used, and the production amount of reduced iron is 20 t / The vehicle was operated under the operating condition h.
[0059]
An example of the raw material composition of the iron ore pellets used as the heat storage is shown in Table 2. Iron ore pellets having a diameter of 5 to 15 mm were passed through a sieve, and those having a diameter of 6 to 9 mm were used as a heat storage body. It was confirmed that the iron ore pellets had the same performance as that of a conventionally used heat storage material such as alumina, and there was no problem in use. The iron ore pellets after use were reused in the reduction furnace of this example as an iron source, but there was no particular problem. Iron ore pellets are iron oxide Fe ₂ O _Three And Fe _Three O _Four Is 90 to 95%, so SiO ₂ -FeO-Al ₂ O _Three The low melting point compound of the system is hardly generated, and even when used as a heat storage body, the surface melts and deterioration of the heat storage body such as gas permeability and welding is suppressed.
[0060]
[Table 2]

[0061]
【The invention's effect】
In the present invention, by installing the regenerative burner in the first half of the reduction process where the volatile components between the agglomerate charging section and the gas discharge section do not volatilize so much, there is no deterioration of the regenerator due to the volatile components, A dust collecting device is not required, and the installation space for the regenerative burner can be reduced, and the initial cost does not increase.
[0062]
In the present invention, as the regenerative burner, a first regenerative burner that burns fuel and combustion oxygen-containing gas through the heat storage body, and only the combustion oxygen-containing gas is blown into the reduction furnace through the heat storage body. Combined with a second regenerative burner that burns part of the combustible gas in the reduction furnace, and the second regenerative burner is installed between the first regenerative burner and the hearth, The reducing gas generated from the inside of the agglomerate can be efficiently burned in the vicinity of the carbonaceous material-containing agglomerate. For this reason, the heat transfer effect to this carbon material interior agglomerate improves, and the heating and reduction reaction of this carbon material interior agglomerate are promoted. Therefore, productivity of reduced iron production can be improved, while the burner exhaust gas amount can be reduced and the fuel consumption rate can be improved.
[0063]
In addition, a regenerative burner is installed in the latter half of the reduction process between the gas discharge part and the reduced iron discharge part, and the atmosphere near the regenerative burner and the carbonaceous agglomerate is changed to an oxidizing atmosphere and a reducing atmosphere, respectively. By maintaining the temperature, a device for replacing with an inert gas is not necessary, and the installation space for the regenerative burner can be reduced, and the time for switching the regenerative burner from the exhaust side to the combustion side can be shortened.
[0064]
Furthermore, the regenerative burner is installed at the upper part of the moving bed type reduction furnace, and is arranged almost horizontally or slightly upward with respect to the hearth of the moving bed type reduction furnace. Since it does not directly hit the surface of the product and does not disturb the atmosphere in the vicinity of the carbonaceous material agglomerate, the reoxidation of the reduced carbonaceous material agglomerate can be prevented and a high metallization rate can be maintained.
[0065]
Furthermore, in the present invention, iron ore pellets or reduced iron is used as a heat storage body, so that it is inexpensive, and even if volatile components or dust components adhere to the reduced iron production facility of the present invention, it is not discarded. Since it can be used as a raw material, the running cost does not increase, and there is no problem such as deterioration of the environment caused by discarding the used heat storage body. Furthermore, the present invention can use a regenerative burner not only for reducing iron but also for producing non-ferrous metals.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of reduced iron production equipment showing a case where a heat storage burner of the present invention is installed in the first half of a reduction process.
FIG. 2 is a conceptual diagram of reduced iron production equipment showing a case where the regenerative burner of the present invention is installed in the latter half of the reduction process.
FIG. 3 is a diagram showing a surface temperature, a dezincification rate, and a zinc generation amount ratio when a carbonaceous material-containing agglomerate is heated.
FIG. 4 is a diagram showing an installation example of a heat storage burner.
FIG. 5 is a view for explaining the installation position of the regenerative burner, where (a) shows the positional relationship between the carbonaceous material agglomerates and the regenerative burner in the furnace, and (b) is an A in (a). FIG.
FIG. 6 is a conceptual diagram showing the atmosphere in the vicinity of the regenerative burner and in the vicinity of the carbonaceous material interior agglomerates at the installation position of the regenerative burner, (a) is a conceptual diagram showing a cross-sectional view of the furnace, (b) FIG. 4 is a diagram showing the distribution of an oxygen gas atmosphere and a reducing gas atmosphere.
FIG. 7 is a view showing a heat storage type burner of the present invention, in which (a) shows a state where the intake / exhaust part 2a is on the combustion side and the intake / exhaust part 2b is on the exhaust side, and (b) is the reverse of (a). It is a figure which shows the state which the intake / exhaust part 2b of this is the combustion side, and the intake / exhaust part 2a is an exhaust side.
FIG. 8 is a conceptual diagram of reduced iron production equipment showing a case where the regenerative burner of the present invention is installed in both the first half and the second half of the reduction process.
FIG. 9 is a diagram showing a difference in fuel consumption rate depending on whether or not a regenerative burner is used.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Carbonaceous material agglomerate, 2 ... Thermal storage burner, 2a, 2b ... Intake / exhaust part, 3 ... Fuel piping, 4a, 4b ... Exhaust gas piping, 5a, 5b ... Fuel switching valve, 6a, 6b ... Exhaust

gas switching valve

7a, 7b ... thermal storage, 8 ... hearth, 10 ... agglomerate charging part, 11 ... reduced iron discharge part, 12 ... gas discharge part.

Claims

In the reduced iron production facility for producing reduced iron by charging a carbonized internal agglomerate composed of an iron oxide-containing material and a carbon-containing reducing material into a moving bed type reducing furnace, the moving bed type reducing furnace Are the agglomerate charging part for charging the carbonaceous material-incorporated agglomerate, the reduced iron discharging part for discharging the reduced iron, and the reduction process from the agglomerate charging part to the reduced iron discharging part. A gas discharge part for discharging the exhaust gas in the furnace , and a regenerative burner as a heating source of the moving bed type reduction furnace between the gas discharge part and the reduced iron discharge part in the latter half of the reduction process And the regenerative burner is installed in an upper part of the moving bed type reduction furnace and is arranged substantially horizontally or slightly upward with respect to the hearth of the moving bed type reduction furnace. Reduced iron production facility characterized by that.

2. The reduced iron production facility according to claim 1, further comprising a regenerative burner which is a first half of the reduction step and is also provided between the agglomerate charging portion and the gas discharge portion. .

The regenerative burner in the first half of the reduction step is installed at a position where the surface temperature of the carbonaceous material agglomerate is 1250 ° C. or less, and the gas discharge part is the carbonaceous material agglomerate. The facility for producing reduced iron according to claim 2, wherein the facility is installed at a position behind a region where the surface temperature of the steel is 1250 ° C. or less.

Any one of claims 1 to 3 combustion gas regenerative burner in the second half portion is in an oxidizing atmosphere, the atmosphere over the carbon composite interior agglomerate is characterized in that it is a reducing atmosphere of said reducing step Reduced iron production facility described in 1.

The regenerative burner in the first half of the reduction step includes a first regenerative burner that burns fuel and combustion oxygen-containing gas through the heat storage body, and only the combustion oxygen-containing gas passes through the heat storage body in the reduction furnace. blow working to be a combination of the second regenerative burner for burning a portion of the combustible gas the reducing furnace, placed before Symbol second regenerative burner of the first regenerative burner The reduced iron production facility according to any one of claims 2 to 4 , wherein the facility is installed below a position.

The regenerative burner in the first half of the reduction step is a regenerative burner in which only combustion oxygen-containing gas is blown into the reduction furnace through a heat storage body to burn a part of the combustible gas in the reduction furnace, further combusting and a combustion oxygen-containing gas fuel, a reduced iron production facility comprising other forms of burner other than regenerative burner, placing a pre-Symbol regenerative burner below the installation position of the burner The reduced iron production facility according to any one of claims 2 to 4 , wherein

Regenerator of thermal storage type burner, reduced iron production facility according to any one of claims 1 to 6, characterized in that said a reduced iron or iron pebble formed product produced by the reduced iron production facility .

The nonferrous metal production facility according to any one of claims 1 to 7 , wherein a part or all of the iron oxide-containing material is a nonferrous metal oxide.

In the method for producing reduced iron, the carbonaceous material-containing agglomerate comprising an iron oxide-containing material and a carbon-containing reducing material is charged into a moving bed type reduction furnace, and reduced iron is produced by heating and reducing in the furnace. The exhaust gas in the furnace is discharged in the first half of the reduction process from charging to discharge of the inner agglomerate, and the carbonaceous material inner agglomerate is installed in the upper part of the moving bed type reducing furnace, and the moving bed Heated with a regenerative burner arranged almost horizontally or slightly upward with respect to the hearth of the type reduction furnace, and the combustion gas of the regenerative burner is made an oxidizing atmosphere, so that the atmosphere in the vicinity of the regenerative burner is A reduced iron is produced while maintaining an atmosphere covering the vicinity of the carbonaceous material agglomerate while reducing the gas generated from the inside of the carbonaceous material agglomerate while maintaining an oxidizing atmosphere. Reduced iron manufacturing method.

The regenerative burner is a first regenerative burner that burns fuel and combustion oxygen-containing gas through a heat storage body, and only the combustion oxygen-containing gas is blown into the reduction furnace through the heat storage body. A second regenerative burner that burns a part of the combustible gas in the second heat storage burner between the agglomerate charging part and the first half of the reduction step. The reduced iron manufacturing method according to claim 9 , wherein the burner is installed below the installation position of the first heat storage burner.

The regenerative burner is a regenerative burner in which only a combustion oxygen-containing gas is blown into the reduction furnace through a heat storage body to burn a part of the combustible gas in the reduction furnace, and further, fuel and combustion oxygen A reduced iron production method comprising a burner of another type other than a regenerative burner for burning the contained gas, wherein the regenerative type is between the agglomerate charging part and the first half of the reduction process. The method for producing reduced iron according to claim 9 , wherein the burner is arranged below the installation position of the burner.

The method for producing reduced iron according to any one of claims 9 to 11 , wherein the heat storage body of the regenerative burner is reduced iron or iron ore agglomerate produced by the reduced iron production method. .

The method for producing a nonferrous metal according to any one of claims 9 to 12 , wherein a part or all of the iron oxide-containing material is a nonferrous metal oxide.