JPH03130314A - Production of iron by smelting reduction method - Google Patents
Production of iron by smelting reduction methodInfo
- Publication number
- JPH03130314A JPH03130314A JP26972289A JP26972289A JPH03130314A JP H03130314 A JPH03130314 A JP H03130314A JP 26972289 A JP26972289 A JP 26972289A JP 26972289 A JP26972289 A JP 26972289A JP H03130314 A JPH03130314 A JP H03130314A
- Authority
- JP
- Japan
- Prior art keywords
- reduction
- fluidized bed
- smelting
- gas
- furnace
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000003723 Smelting Methods 0.000 title claims abstract description 44
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 30
- 238000000034 method Methods 0.000 title claims abstract description 16
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 title abstract description 16
- 239000002994 raw material Substances 0.000 claims abstract description 10
- 230000003647 oxidation Effects 0.000 claims description 38
- 238000007254 oxidation reaction Methods 0.000 claims description 38
- 238000011946 reduction process Methods 0.000 claims description 21
- 238000002844 melting Methods 0.000 claims description 7
- 230000008018 melting Effects 0.000 claims description 7
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 4
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 claims description 3
- 239000007789 gas Substances 0.000 abstract description 74
- 239000003245 coal Substances 0.000 abstract description 16
- 238000002485 combustion reaction Methods 0.000 abstract description 12
- 229910015189 FeOx Inorganic materials 0.000 abstract description 6
- 238000002407 reforming Methods 0.000 abstract description 4
- 239000004215 Carbon black (E152) Substances 0.000 abstract description 2
- 239000000446 fuel Substances 0.000 abstract description 2
- 229930195733 hydrocarbon Natural products 0.000 abstract description 2
- 150000002430 hydrocarbons Chemical class 0.000 abstract description 2
- 230000001590 oxidative effect Effects 0.000 abstract 5
- 239000002912 waste gas Substances 0.000 abstract 1
- 239000000203 mixture Substances 0.000 description 6
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000009434 installation Methods 0.000 description 3
- 239000012256 powdered iron Substances 0.000 description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910017108 Fe—Fe Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000006114 decarboxylation reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
Landscapes
- Manufacture Of Iron (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、粉状の鉄鉱石を流動層からなる予備還元炉に
よって予備還元したのち溶融還元する製鉄法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an iron manufacturing method in which powdered iron ore is pre-reduced in a pre-reduction furnace consisting of a fluidized bed and then melted and reduced.
粉状の鉄鉱石を流動層からなる予備還元炉により還元し
、得られた予備還元鉱石を、例えば鉄浴中の炭素とスラ
グ中の炭材で還元精錬すると同時に上吹酸素により二次
燃焼を行って溶融還元すること自体、例えば特開昭６２
−１９２５１３号公報に開示されているように本発明の
出願前から公知である。Powdered iron ore is reduced in a pre-reduction furnace consisting of a fluidized bed, and the pre-reduced ore obtained is reduced and refined using, for example, carbon in an iron bath and carbonaceous material in slag, and at the same time secondary combustion is performed using top-blown oxygen. The process of melting and reduction itself is described in, for example, JP-A-62
As disclosed in Japanese Patent Publication No. 192513, it has been known since before the application of the present invention.
このような溶融還元製鉄法は従来の高炉による製鉄法と
比較して、付帯設備が小設備で済む、使用原料の制約が
少ない等の利点はあるが、この溶融還元製鉄法における
欠点の一つとして、使用する石炭の原単位が大きいとい
うことがある。This type of smelting reduction iron manufacturing method has advantages over the conventional iron manufacturing method using a blast furnace, such as requiring only a small amount of incidental equipment and fewer restrictions on the raw materials used, but one of the disadvantages of this smelting reduction iron manufacturing method is that As a result, the basic unit of coal used is large.
溶融還元炉に供給される予備還元鉱石の還元率が３０％
以下のように低還元率の場合には、溶融還元炉における
二次燃焼率を高くすることによって、システム全体の石
炭原単位の低減が可能である。The reduction rate of pre-reduced ore supplied to the smelting reduction furnace is 30%.
In the case of a low reduction rate as described below, it is possible to reduce the coal consumption rate of the entire system by increasing the secondary combustion rate in the smelting reduction furnace.
ところが、溶融還元炉における二次燃焼率を高くするこ
とにより溶融還元炉の二次燃焼区域の温度が高くなり、
そのために炉の内張り耐火物の損耗が促進され、炉の寿
命を極端に短くし、システム全体から見て製鉄の生産効
率が低いものとならざるを得ず好ましくない。However, by increasing the secondary combustion rate in the smelting reduction furnace, the temperature in the secondary combustion zone of the smelting reduction furnace becomes higher.
This accelerates the wear and tear of the refractory lining of the furnace, extremely shortens the life of the furnace, and undesirably lowers the production efficiency of iron manufacturing from the perspective of the entire system.
そのため、例えば、特願昭６３−１６７２３号出願明細
書に開示されているような微粉炭の吹き込みによる温度
低下によって解消しようとする試みも提案されたが、吹
き込みに使用した石炭量だけ石炭原単位が増加するとい
う欠点がある。Therefore, for example, an attempt was proposed to solve the problem by lowering the temperature by blowing pulverized coal as disclosed in the specification of Japanese Patent Application No. 16723/1982, but the amount of coal used for blowing is The disadvantage is that it increases.
一方、溶融還元炉に供給される予備還元鉱石の還元率を
、例えば３０％以上のように高い値にすることは、溶融
還元炉で必要とされる還元剤および熱源としての石炭量
が少なくなるという点で有利であり、また、低還元率の
予備還元鉱石の使用の場合のように二次燃焼率を高くす
る必要がなく炉の内張り耐火物の損耗の問題も軽減され
、システム全体として高炉による製鉄法程度あるいはそ
れ以下の石炭原単位となることが期待できる。On the other hand, increasing the reduction rate of the pre-reduced ore supplied to the smelting reduction furnace to a high value, for example 30% or more, will reduce the amount of coal needed as a reducing agent and heat source in the smelting reduction furnace. In addition, there is no need to increase the secondary combustion rate as in the case of using pre-reduced ore with a low reduction rate, and the problem of wear and tear on the furnace lining refractory is alleviated. It is expected that the coal consumption rate will be on the same level as or lower than that of the steel manufacturing method.
この３０％以上の比較的高い還元率を有する予備還元鉱
石を得る流動層からなる予備還元プロセスとして、流動
層を複数段に設けたものも、また、特開昭６３−１６２
８０３号公報、特開平１−１４９９１１号公報等に開示
されている。As a pre-reduction process using a fluidized bed to obtain a pre-reduced ore with a relatively high reduction rate of 30% or more, a method in which a fluidized bed is provided in multiple stages is also disclosed in Japanese Patent Application Laid-Open No. 63-162.
This method is disclosed in Japanese Patent Publication No. 803, Japanese Unexamined Patent Publication No. 1-149911, and the like.
ところが、かかる従来の多段の流動予備還元炉による溶
融還元製鉄法においては、その段数が２段程度では、最
終流動予備還元炉の出口ガスの酸化度が低くガス還元に
必要なガス量が多く、特開昭６２−２２７０２０号公報
に記載されているようなガスの改質および循環の装置が
必要となり、溶融還元システム全体の設備を膨大なもの
とする欠点がある。また、３段以上の多段の流動層から
なる予備還元プロセスにおいて最終流動予備還元炉の出
口ガスの酸化度を高くすることは可能だが、予備還元プ
ロセスの設備費が大きくなるという欠点がある。However, in the conventional smelting reduction iron manufacturing method using a multi-stage fluidized pre-reduction furnace, when the number of stages is about two, the degree of oxidation of the exit gas of the final fluidized pre-reduced furnace is low and the amount of gas required for gas reduction is large. This requires a gas reforming and circulation device as described in Japanese Patent Application Laid-Open No. 62-227020, which has the disadvantage that the entire equipment for the melting reduction system becomes enormous. Furthermore, although it is possible to increase the degree of oxidation of the outlet gas of the final fluidized pre-reduction furnace in a pre-reduction process consisting of three or more stages of fluidized beds, there is a drawback that the equipment cost for the pre-reduction process increases.
本発明は、溶融還元製鉄法における石炭原単位の低減と
高生産効率という目的を実現するうえで、粉状の鉄鉱石
を２段流動層からなる予備還元プロセスにおいて３０％
以上の高予備還元率を得るとともに予備還元プロセスか
らの出口ガスの酸化度を高めることにより、３０％以下
の低予備還元率において石炭原単位の低減のために必要
な高二次燃焼率において生ずる溶融還元炉の内張り耐火
物の損耗による低生産効率の問題と、従来の多段の流動
層からなる予備還元プロセスを備えた溶融還元製鉄法に
おいて３０％以上の高予備還元率を得るために生ずる還
元ガスの脱炭酸と循環の装置の設置もしくは３段以上の
多段の流動層の設置による設備費の上昇の問題とを解消
することにある。In order to achieve the objectives of reducing coal consumption and high production efficiency in the smelting reduction ironmaking process, the present invention aims to reduce powdered iron ore by 30% in a pre-reduction process consisting of a two-stage fluidized bed.
By obtaining a high pre-reduction rate of 30% or less and increasing the degree of oxidation of the exit gas from the pre-reduction process, the melting that occurs at the high secondary combustion rate necessary for reducing the coal consumption rate at a low pre-reduction rate of 30% or less. The problem of low production efficiency due to wear and tear of the refractory lining of the reduction furnace, and the reduction gas generated in order to obtain a high preliminary reduction rate of 30% or more in the conventional smelting reduction ironmaking process equipped with a preliminary reduction process consisting of multiple stages of fluidized beds. The purpose of the present invention is to solve the problem of increased equipment costs due to the installation of decarboxylation and circulation equipment or the installation of three or more stages of fluidized beds.
本発明は、予備還元流動層によって３０％以上の還元率
を有する予備還元鉱を得、これを溶融還元炉に供給する
溶融還元製鉄法において、予備還元プロセスを流動層２
段から構成し、この２段の流動層を還元ガスの流れと幹
給原料鉱石の流れが向流且つ直列になるべく配置すると
ともに前記直列且つ２段に配置された予備還元流動層の
原料鉱石供給側の１段目の流動層の出口ガス酸化度をこ
こでの中間の予備還元率を１１〜２５％とすることによ
りＦｅ−ＦｅＯｘ還元系における平衡ガス酸化度より高
く且つＦｅ０ｘ−Ｆｅ３０４還元系における平衡ガス酸
化度より低い値に維持し、且つ溶融還元炉側の２段目の
流動層の出口ガス酸化度を溶融還元炉の二次燃焼率の制
御によってもしくは溶融還元炉の排ガスのそのＵ熱を利
用した石炭または炭化水素系燃料を用いた改質によって
同溶融還元炉側の２段目の流動層の入口ガス酸化度を調
整することによりＦｅ−ＦｅＯｘ還元系における平衡ガ
ス酸化度より低い値に維持し予備還元率を３０％以上と
することを特徴とする。The present invention involves a smelting reduction ironmaking process in which pre-reduced ore having a reduction rate of 30% or more is obtained using a pre-reduced fluidized bed and is supplied to a smelting reduction furnace.
The two-stage fluidized bed is arranged so that the flow of the reducing gas and the flow of the main raw material ore are countercurrent and in series, and the raw material ore is supplied to the pre-reduction fluidized bed arranged in series and in the two stages. By setting the intermediate preliminary reduction rate of the exit gas oxidation degree of the first stage fluidized bed on the side to 11 to 25%, it is higher than the equilibrium gas oxidation degree in the Fe-FeOx reduction system, and is higher than the equilibrium gas oxidation degree in the FeOx-Fe304 reduction system. The oxidation degree of the outlet gas of the second stage fluidized bed on the smelting reduction furnace side is maintained at a value lower than the equilibrium gas oxidation degree by controlling the secondary combustion rate of the smelting reduction furnace or by controlling the U heat of the exhaust gas of the smelting reduction furnace. By adjusting the inlet gas oxidation degree of the second stage fluidized bed on the same smelting reduction furnace side by reforming using coal or hydrocarbon fuel, the gas oxidation degree is lower than the equilibrium gas oxidation degree in the Fe-FeOx reduction system. It is characterized by maintaining the preliminary return rate at 30% or more.
予備還元流動層２段が還元ガスの流れと供給原料鉱石の
流れとが向流且つ直列となるように配置された上記予備
還元プロセスにおいて例えば１段目の低予備還元側流動
層の還元温度が８００℃で２段目の高予備還元側流動層
の還元温度が９００℃であったとする。９００℃におけ
るＦｅ−Ｆｅ０に還元系における平衡ガス酸化度は３５
％であり、８００℃におけるＦｅ−Ｆｅ０に還元系にお
ける平衡ガス酸化度は３７％でＰｅ０Ｘ−Ｆｅ３ｆｆ４
の還元系における平衡ガス酸化度は７４％である。In the above pre-reduction process in which the two stages of the pre-reduction fluidized bed are arranged so that the flow of the reducing gas and the flow of the feedstock ore are countercurrent and in series, for example, the reduction temperature of the low pre-reduction side fluidized bed in the first stage is Assume that the reduction temperature of the second stage high preliminary reduction side fluidized bed is 900°C at 800°C. The equilibrium gas oxidation degree in the Fe-Fe0 reduction system at 900°C is 35
%, and the equilibrium gas oxidation degree in the Fe-Fe0 reduction system at 800°C is 37%, which is Pe0X-Fe3ff4.
The equilibrium gas oxidation degree in the reduction system is 74%.
１段目の低予備還元側の流動層における出口ガスの温度
が８００℃のとき、同高予備還元側の流動層における中
間予備還元鉱石の還元率を１１〜２５％に制御する。そ
の制御方法はたとえば特開昭６３−１６２８０３号公報
に記載されているように流動層内鉱石滞留量の制御によ
り可能である。すなわち、中間予備還元鉱石の還元率が
１１〜２５％のとき、低予備還元側の流動層の出口ガス
の酸化度は上記条件の３７〜７４％中にあるように制御
される。When the temperature of the outlet gas in the fluidized bed on the low pre-reduction side of the first stage is 800°C, the reduction rate of the intermediate pre-reduced ore in the fluidized bed on the same high pre-reduction side is controlled to 11 to 25%. This can be controlled by controlling the amount of ore retained in the fluidized bed, as described in, for example, Japanese Patent Laid-Open No. 162803/1983. That is, when the reduction rate of the intermediate pre-reduced ore is 11 to 25%, the degree of oxidation of the outlet gas of the fluidized bed on the low pre-reduction side is controlled to be within the range of 37 to 74% under the above conditions.
溶融還元炉からの排出ガスをその酸化度を溶融還元炉の
二次燃焼率を制御することまたは改質することによって
調整し２段目の高予備還元側の流動層での還元用のガス
として用いれば、同高予備還元側の流動層出口ガスの酸
化度を、還元率が１１〜２５％の中間予備還元鉱石を同
高予備還元側の流動層において予備還元率が３０％以上
の目標の値まで還元した時に必要とされるガス利用率の
分だけ還元ガスの酸化度が上昇しても、Ｆｅ−ＦｅＯｘ
還元系における平衡ガス酸化度以下例えば９００℃のと
き３５％以下とすることが可能である。The degree of oxidation of the exhaust gas from the smelting reduction furnace is adjusted by controlling the secondary combustion rate of the smelting reduction furnace or by reforming it, and it is used as a reducing gas in the fluidized bed on the high preliminary reduction side of the second stage. If used, the degree of oxidation of the fluidized bed outlet gas on the same-high pre-reduction side can be changed to the intermediate pre-reduced ore with a reduction rate of 11 to 25% in the fluidized bed on the same-high pre-reduction side with a target pre-reduction rate of 30% or more. Fe-FeOx
The oxidation degree of the equilibrium gas in the reducing system can be set to 35% or less at 900° C., for example.
低予備還元側の流動層の出口ガスの酸化度がＦｅＬ−Ｆ
ｅｒＬの還元系における平衡ガス酸化度をこえるとき、
中間予備還元鉱石の還元率は１１％以下であり、このよ
うな低還元率の中間予備還元鉱石を２段目の高予備還元
側の流動層においてその出口ガス酸化度がＰｅ−Ｆｅｎ
、還元系における平衡ガス酸化度以下で予備還元率が３
０％以上の目標の値まで還元することは不可能である。The degree of oxidation of the outlet gas of the fluidized bed on the low preliminary reduction side is FeL-F.
When the equilibrium gas oxidation degree in the reduction system of erL is exceeded,
The reduction rate of the intermediate pre-reduced ore is 11% or less, and the intermediate pre-reduced ore with such a low reduction rate is processed in the fluidized bed on the high pre-reduction side of the second stage so that the outlet gas oxidation degree is Pe-Fen.
, the preliminary reduction rate is 3 below the equilibrium gas oxidation degree in the reduction system.
It is impossible to reduce the amount to a target value of 0% or more.
溶融還元炉に供給される予備還元鉱石の還元率が３０％
以下となると、石炭原単位は溶融還元炉での二次燃焼率
を高くしないと上昇する。The reduction rate of pre-reduced ore supplied to the smelting reduction furnace is 30%.
Below, the coal consumption rate will increase unless the secondary combustion rate in the smelting reduction furnace is increased.
低予備還元側の流動層の出口ガスの酸化度がＦｅ−Ｆｅ
Ｏｘ還元系における平衡ガス酸化度以下ということは予
備還元プロセスでのガス利用率が低いことを意味し、予
備還元鉱石の還元率を３０％以上とするためには、還元
ガスの循環が必須となり関連設備の設置が不可欠となり
設備費の上昇が避けられない。The degree of oxidation of the outlet gas of the fluidized bed on the low preliminary reduction side is Fe-Fe.
The fact that the degree of oxidation of the gas in the Ox reduction system is below the equilibrium gas means that the gas utilization rate in the pre-reduction process is low, and in order to achieve a reduction rate of 30% or more for the pre-reduced ore, circulation of the reducing gas is essential. The installation of related equipment is essential, and an increase in equipment costs is unavoidable.
このようにして、予備還元プロセスから排出されるガス
の酸化度すなわち１段目の低予備還元側の流動層の出口
ガス酸化度は、溶融還元炉に供給する予備還元鉱石が３
０％以上の高予備還元率となることを確保しつつ、Ｆｅ
−Ｆｅ０＋＋ 還元系における平衡ガス酸化度を越える
ことが可能となり予備還元プロセス全体でのガス利用率
を高めることができるので、溶融還元炉において適当な
二次燃焼率を設定すれば設備費の上昇と生産効率の低下
を回避しつつ高炉による製鉄法程度あるいはそれ以下の
石炭原単位が可能である。In this way, the degree of oxidation of the gas discharged from the pre-reduction process, that is, the degree of oxidation of the gas at the outlet of the fluidized bed on the low pre-reduction side of the first stage, is set to 3.
While ensuring a high preliminary return rate of 0% or more,
-Fe0++ It is possible to exceed the equilibrium gas oxidation degree in the reduction system and increase the gas utilization rate in the entire preliminary reduction process, so if an appropriate secondary combustion rate is set in the smelting reduction furnace, equipment costs will increase. It is possible to achieve a coal consumption rate comparable to or lower than that of the blast furnace steel manufacturing method while avoiding a decrease in production efficiency.
第１図は本発明の方法を実施するための溶融還元プロセ
スを示す。FIG. 1 shows a melt reduction process for carrying out the method of the invention.
同図を参照して、本発明の溶融還元方法は粉鉱石の予備
還元プロセス１と溶融還元プロセスとからなる。Referring to the figure, the smelting reduction method of the present invention includes a preliminary reduction process 1 of fine ore and a smelting reduction process.
粉鉱石の予備還元プロセス１は流動層２段からなり、１
段目の低予備還元側流動層２と２段目の高予備還元側流
動層３とからなる。この低予備還元側流動層２と高予備
還元側流動層３は、低予備還元側流動層、２に供給され
溶融還元炉４に到る太線で示された原料鉱石の流れと、
溶融還元炉４のガス出口付近で改質され、各流動層２．
３を経て排出される細線で示す還元ガスの流れとが直列
且つ向流するように配置されている。Pre-reduction process 1 of fine ore consists of two stages of fluidized bed, 1
It consists of a low preliminary reduction side fluidized bed 2 in the first stage and a high preliminary reduction side fluidized bed 3 in the second stage. The low preliminary reduction side fluidized bed 2 and the high preliminary reduction side fluidized bed 3 are connected to the flow of raw material ore shown by the thick line, which is supplied to the low preliminary reduction side fluidized bed 2 and reaches the smelting reduction furnace 4.
The gas is reformed near the gas outlet of the melting reduction furnace 4, and each fluidized bed 2.
The flow of the reducing gas shown by the thin line discharged through 3 is arranged in series and in counterflow.
低予備還元側流動層２に供給される原料鉱石５は、同高
予備還元側流動層２において初期還元され、中間予備還
元鉱石６として高予備還元側流動層３に供給され、さら
に同高予備還元側流動層３において少なくとも３０％に
還元された予備還元鉱石７として溶融還元炉４に連続し
て供給される鉱石の流れとなる。この予備還元鉱石７は
、チャーのような炭素材、精錬材および酸素ガス８と共
に溶融還元炉４に供給され、最終的に１００％還元され
た溶融鉄を懲戒する。The raw material ore 5 supplied to the low preliminary reduction side fluidized bed 2 is initially reduced in the high preliminary reduction side fluidized bed 2, and is supplied to the high preliminary reduction side fluidized bed 3 as intermediate preliminary reduction ore 6, and then further reduced to the high preliminary reduction side fluidized bed 3. This is a stream of ore that is continuously supplied to the smelting reduction furnace 4 as the pre-reduced ore 7 reduced to at least 30% in the reduction side fluidized bed 3. This pre-reduced ore 7 is supplied to the smelting reduction furnace 4 together with a carbon material such as char, a refining material, and an oxygen gas 8, and finally the 100% reduced molten iron is refined.
この溶融還元プロセスで生成された溶融還元炉４の出口
ガス９は、ガス改質装置ｌＯを経て還元ガス１１を懲戒
し、高予備還元側流動層３に供給される。この還元ガス
１１は、高予備還元側流動層３内に供給される中間予備
還元鉱石６を目標とする３０％以上の還元率まで還元す
る。さらに、高予備還元側流動層３より排出される中間
還元ガス１２は低予備還元側流動層２に供給され、出発
原料鉱石５を１１〜２５％の還元率まで還元したのち、
予備還元プロセス１からの排ガス１３として排出する。The outlet gas 9 of the smelting reduction furnace 4 generated in this smelting reduction process is supplied to the high pre-reduction side fluidized bed 3 after passing through the gas reformer 1O to convert the reducing gas 11. This reducing gas 11 reduces the intermediate pre-reduced ore 6 supplied into the high pre-reduction side fluidized bed 3 to a target reduction rate of 30% or more. Further, the intermediate reducing gas 12 discharged from the high preliminary reduction side fluidized bed 3 is supplied to the low preliminary reduction side fluidized bed 2, and after reducing the starting raw material ore 5 to a reduction rate of 11 to 25%,
It is discharged as exhaust gas 13 from the preliminary reduction process 1.
上記、添付図に示すプロセスにおいて、溶融還元炉４に
おける二次燃焼率を３５％に設定した。In the process shown in the attached diagram above, the secondary combustion rate in the melting reduction furnace 4 was set to 35%.
このとき、溶融還元炉４からの出口ガス９の組成は、Ｎ
２： １０％、Ｈ，０：１７％、ＣＯ：５４％、ＣＯ２
：１７％、Ｎ２：２％であって、その酸化度は３５％で
あった。At this time, the composition of the outlet gas 9 from the melting reduction furnace 4 is N
2: 10%, H, 0: 17%, CO: 54%, CO2
:17%, N2:2%, and the degree of oxidation was 35%.
この出口ガス９が溶融還元炉４から導かれる煙道内にノ
ズルによって微粉炭を吹き込む構造を有するガス改質装
置１０を用いて、出口ガス９のガス組成をＮ２：２１％
、）１２０：１０％、ＣＯ：５６％、ＣＯ２：１１％、
Ｎ２：２％の組成をもつ還元ガス１１に改質し、その酸
化度を２１％に低下せしめ、予備還元プロセス１に導入
した。The gas composition of the outlet gas 9 is changed to N2:21% using a gas reformer 10 having a structure in which pulverized coal is injected by a nozzle into a flue through which the outlet gas 9 is guided from the smelting reduction furnace 4.
)120:10%, CO:56%, CO2:11%,
It was reformed into reducing gas 11 having a composition of N2:2%, its oxidation degree was lowered to 21%, and it was introduced into preliminary reduction process 1.
原料鉱石５は、乾揉・予熱したのち低予備還元側流動層
２に装入した。The raw material ore 5 was dry-milled and preheated, and then charged into the low preliminary reduction side fluidized bed 2.
低予備還元側流動層２から排出される中間予備還元鉱石
６の還元率を１９％として同高予備還元側流動層２の排
ガス１３の組成をＦｅ−ＰｅＯｘ還元系における平衡ガ
ス酸化度より高（且つＦｅ０ｘ−Ｆｅ３０４の還元系に
おける平衡ガス酸化度より低い４１％に設定し、且つ高
予備還元側流動層３の出側の中間還元ガス１２の組成を
Ｐｅ−ＦｅＯｘ 還元系における平衡ガス酸化度より低
い３３％で同高予備還元側流動層３から排出される予備
還元鉱石７の還元率を５０％に設定し、これをガス改質
装置１０によって制御した。Assuming that the reduction rate of the intermediate pre-reduced ore 6 discharged from the low pre-reduction fluidized bed 2 is 19%, the composition of the exhaust gas 13 of the same high pre-reduction fluidized bed 2 is set to be higher than the equilibrium gas oxidation degree in the Fe-PeOx reduction system ( In addition, the composition of the intermediate reducing gas 12 on the outlet side of the high preliminary reduction side fluidized bed 3 is set to 41%, which is lower than the equilibrium gas oxidation degree in the Fe0x-Fe304 reduction system, and the composition is set to 41%, which is lower than the equilibrium gas oxidation degree in the Pe-FeOx reduction system. The reduction rate of the pre-reduced ore 7 discharged from the same-high pre-reduction side fluidized bed 3 at a low level of 33% was set to 50%, and this was controlled by the gas reformer 10.
これによって、使用した一般炭の原単位は製造した溶鉄
１トン当たり８５０ｋｇであって、略従来の高炉法と比
較できる程度まで低下した。As a result, the basic unit of steam coal used was 850 kg per ton of molten iron produced, which was reduced to a level comparable to that of the conventional blast furnace method.
本発明の溶融還元法によって以下の効果を奏することが
できる。The following effects can be achieved by the melt reduction method of the present invention.
（１） 予備還元率３０％以上で且つ高ガス利用率を
得ることか可能となり、溶融還元システム全体での石炭
原単位を低減し、且つ生産効率を高くすることができる
。(1) It is possible to obtain a preliminary reduction rate of 30% or more and a high gas utilization rate, thereby reducing the coal consumption rate of the entire smelting reduction system and increasing production efficiency.
（２）溶融還元炉の排ガスを比較的簡単な改質装置によ
って酸化度を下げるだけで、直列した流動層に導入され
るものであるので、ガス循環装置その他の巨大設備を必
要としない。(2) Since the exhaust gas from the smelting reduction furnace is introduced into the series fluidized bed by simply lowering the degree of oxidation using a relatively simple reformer, there is no need for a gas circulation device or other huge equipment.
第１図は本発明の溶融還元製鉄法のプロセスフローの実
施例を示す図である。
１：予備還元プロセス ２：低予備還元側流動層３：高
予備還元側流動層
４；溶融還元炉 ５：原料鉱石
６：中間予備還元鉱石 ７：予備還元鉱石８：酸素ガス
９：溶融還元炉出口ガス１０：ガス改質装置
１１：還元ガス
１２：高予備還元側流動層出側の中間還元ガス１３：予
備還元プロセス排ガス
慎
図FIG. 1 is a diagram showing an example of the process flow of the smelting reduction iron manufacturing method of the present invention. 1: Pre-reduction process 2: Low pre-reduction side fluidized bed 3: High pre-reduction side fluidized bed 4; Smelting reduction furnace 5: Raw material ore 6: Intermediate pre-reduction ore 7: Pre-reduction ore 8: Oxygen gas 9: Smelting reduction furnace Outlet gas 10: Gas reformer 11: Reducing gas 12: Intermediate reducing gas on the high preliminary reduction side fluidized bed outlet side 13: Preliminary reduction process exhaust gas diagram
Claims (1)
石の流れとが向流かつ直列となるように配置された予備
還元プロセスによって３０％以上の還元率を有する予備
還元鉱石を得、これを溶融還元炉にて溶融還元し溶融鉄
を得る溶融還元製鉄法において、前記予備還元プロセス
の直列且つ２段に配置された予備還元流動層の原料鉱石
供給側の１段目（低予備還元率側）の流動層の出口ガス
酸化度を鉄Ｆｅ−ウスタイトＦｅＯ＿ｘの還元平衡ガス
酸化度より高く且つウスタイトＦｅＯ＿ｘ−マグネタイ
トＦｅ＿２Ｏ＿４の還元平衡ガス酸化度より低い値に維
持し、また溶融還元炉側の２段目（高予備還元率側）の
流動層の入口ガス酸化度を鉄Ｆｅ−ウスタイトＦｅＯ＿
ｘの還元平衡ガス酸化度より低い値に維持する予備還元
プロセスを備えた溶融還元製鉄法。1. Obtain pre-reduced ore with a reduction rate of 30% or more through a pre-reduction process in which two stages of pre-reduced fluidized beds are arranged so that the flow of reducing gas and the flow of feedstock ore are countercurrent and in series; In the smelting reduction iron making method in which molten iron is obtained by smelting and reducing this in a smelting reduction furnace, the first stage on the raw material ore supply side of the pre-reduction fluidized bed (low pre-reduction The exit gas oxidation degree of the fluidized bed on the side of the melting reduction furnace is maintained at a value higher than the reduction equilibrium gas oxidation degree of iron Fe-wustite FeO_x and lower than the reduction equilibrium gas oxidation degree of wustite FeO_x-magnetite Fe_2O_4. The inlet gas oxidation degree of the second stage (high preliminary reduction rate side)
A smelting reduction ironmaking process with a pre-reduction process that maintains the reduction equilibrium gas oxidation degree of x below a value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26972289A JPH0637661B2 (en) | 1989-10-16 | 1989-10-16 | Smelting reduction ironmaking method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26972289A JPH0637661B2 (en) | 1989-10-16 | 1989-10-16 | Smelting reduction ironmaking method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03130314A true JPH03130314A (en) | 1991-06-04 |
| JPH0637661B2 JPH0637661B2 (en) | 1994-05-18 |
Family
ID=17476255
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26972289A Expired - Lifetime JPH0637661B2 (en) | 1989-10-16 | 1989-10-16 | Smelting reduction ironmaking method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0637661B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003089007A (en) * | 2001-09-12 | 2003-03-25 | Mitsubishi Materials Corp | Boring tool |
| JP2007331042A (en) * | 2006-06-13 | 2007-12-27 | Tokuden Co Ltd | Deep hole machining device |
| JP2015078403A (en) * | 2013-10-15 | 2015-04-23 | 新日鐵住金株式会社 | Direct reduction method |
| US10005138B2 (en) | 2013-05-28 | 2018-06-26 | Allied Machine & Engineering Corp. | Vacuum drilling system and methods |
| CN114538569A (en) * | 2022-02-25 | 2022-05-27 | 中国科学技术大学 | Fe coated with chitosan-derived carbon shell0/FeOxGranular electro-Fenton cathode and preparation and application thereof |
-
1989
- 1989-10-16 JP JP26972289A patent/JPH0637661B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003089007A (en) * | 2001-09-12 | 2003-03-25 | Mitsubishi Materials Corp | Boring tool |
| JP2007331042A (en) * | 2006-06-13 | 2007-12-27 | Tokuden Co Ltd | Deep hole machining device |
| US10005138B2 (en) | 2013-05-28 | 2018-06-26 | Allied Machine & Engineering Corp. | Vacuum drilling system and methods |
| JP2015078403A (en) * | 2013-10-15 | 2015-04-23 | 新日鐵住金株式会社 | Direct reduction method |
| CN114538569A (en) * | 2022-02-25 | 2022-05-27 | 中国科学技术大学 | Fe coated with chitosan-derived carbon shell0/FeOxGranular electro-Fenton cathode and preparation and application thereof |
| CN114538569B (en) * | 2022-02-25 | 2023-03-10 | 中国科学技术大学 | Fe coated with chitosan-derived carbon shell 0 /FeO X Granular electro-Fenton cathode and preparation and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0637661B2 (en) | 1994-05-18 |
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