WO2023233957A1 - Blast-furnace operation method and blast furnace - Google Patents
Blast-furnace operation method and blast furnace Download PDFInfo
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- WO2023233957A1 WO2023233957A1 PCT/JP2023/017685 JP2023017685W WO2023233957A1 WO 2023233957 A1 WO2023233957 A1 WO 2023233957A1 JP 2023017685 W JP2023017685 W JP 2023017685W WO 2023233957 A1 WO2023233957 A1 WO 2023233957A1
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- blast furnace
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- 238000000034 method Methods 0.000 title claims abstract description 19
- 239000000571 coke Substances 0.000 claims abstract description 53
- 239000007789 gas Substances 0.000 claims abstract description 52
- 238000002485 combustion reaction Methods 0.000 claims abstract description 35
- 239000011261 inert gas Substances 0.000 claims abstract description 22
- 238000011038 discontinuous diafiltration by volume reduction Methods 0.000 claims abstract description 6
- 238000011017 operating method Methods 0.000 claims description 21
- 239000000463 material Substances 0.000 claims description 11
- 238000007664 blowing Methods 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 13
- 239000001301 oxygen Substances 0.000 abstract description 13
- 229910052760 oxygen Inorganic materials 0.000 abstract description 13
- 230000003247 decreasing effect Effects 0.000 abstract description 2
- 230000002542 deteriorative effect Effects 0.000 abstract description 2
- 238000005422 blasting Methods 0.000 abstract 7
- 239000000155 melt Substances 0.000 abstract 1
- 238000010079 rubber tapping Methods 0.000 abstract 1
- 230000008569 process Effects 0.000 description 9
- 239000002893 slag Substances 0.000 description 7
- 239000012768 molten material Substances 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000008439 repair process Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 240000001549 Ipomoea eriocarpa Species 0.000 description 1
- 235000005146 Ipomoea eriocarpa Nutrition 0.000 description 1
- 229910000805 Pig iron Inorganic materials 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000011112 process operation Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000009418 renovation Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B5/00—Making pig-iron in the blast furnace
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B7/00—Blast furnaces
Definitions
- the present invention relates to a blast furnace operating method for stopping the operation, resting the blast furnace, and then restarting the blast furnace, and a blast furnace used in the blast furnace operating method.
- blast furnace operations have not stopped since firing, except for short-term shutdowns for periodic equipment repairs, and although operations have been adjusted such as reducing production, it has been assumed that operations will continue. ing. This is because the cost of restarting operations due to a shutdown is enormous and is not economically rational, and once operations are stopped, it takes about half a year to restart, so there is no upward elasticity with respect to production volume. It will be done.
- blast furnace operations are now required to be flexible to large fluctuations in production, and the importance of banking to shut down operations while it is possible to restart them is increasing.
- Patent Document 1 in order to prevent troubles in repair work, the incombustible materials introduced into the furnace have a low melting point composition, thereby deteriorating the discharge performance when restarting the furnace. He was trying to deter him.
- Patent Document 2 it was found that not only the remaining coke is reduced in diameter due to combustion consumption, but also that the pig iron, slag, etc. attached to the coke are remelted when restarting operations, leading to an increase in the amount of molten material. After the coke was intentionally burnt out using a burner, new coke was charged to prevent the amount of molten material from increasing when restarting the plant.
- Patent Document 1 in addition to the in-furnace slag that is generated upon resumption of operation, low-melting point incombustibles are injected from outside the system, which still poses a problem in that it leads to an increase in the amount of slag that must be discharged. was left. Additionally, Patent Document 2 is more advanced in that it suppresses the increase in the amount of molten material compared to the conventional technology, but it does not prevent diameter reduction itself due to combustion of newly charged coke. However, the problem was that the longer the banking period, the smaller the diameter due to the combustion consumption of coke and the accompanying deterioration in emissions.
- the purpose of the present invention is to suppress the reduction in diameter due to the combustion consumption of coke, which could not be achieved in the previous patent, and to prevent the deterioration of the discharge performance of the molten material, thereby enabling smooth restart of the blast furnace.
- the aim is to propose operating methods and blast furnaces.
- the blast furnace operating method of the present invention was developed to solve the above-mentioned problems, and is a blast furnace operating method for stopping the operation, taking a break from the blast furnace, and then restarting the blast furnace.
- a combustion process involves blowing oxygen-containing gas through a burner inserted into the taphole after the wind has finished, and burning the coke remaining in the furnace to reduce the volume of the remaining material in the furnace, and adding new coke to the volume reduction area.
- the method for operating a blast furnace the method includes a charging step in which air is introduced into the furnace, and a blowing step in which air is restarted from the tuyeres. This is a blast furnace operating method that includes an introduction step.
- the blast furnace operating method configured as described above, (1) further comprising a determination step of determining whether or not combustion of coke in the blast furnace continues after the introduction step; (2) In the determination step, the concentration of gas in the blast furnace is analyzed, and if the concentration of CO gas is equal to or higher than a threshold value, determining that the combustion of coke in the blast furnace continues; (3) further comprising an additional step of charging additional coke up to the upper part of the tuyere when it is determined in the determination step that the combustion of coke in the blast furnace continues; (4) In the introduction step, the amount of inert gas introduced into the blast furnace is in the range of 7% to 13% of the blast furnace volume per hour; (5) In the introduction step, the inert gas is introduced into the blast furnace through an inlet formed above the tuyere of the blast furnace; is considered to be a more preferable solution.
- the blast furnace of the present invention is a blast furnace that implements the above-described blast furnace operating method, and is a blast furnace in which an inlet for introducing inert gas is formed above the tuyere.
- the blast furnace operating method and blast furnace of the present invention by introducing an inert gas into the blast furnace, it is possible to prevent diameter reduction due to combustion consumption of coke in the blast furnace. Thereby, the blast furnace can be restarted smoothly by preventing deterioration in the discharge performance of the molten material. Furthermore, since the present invention does not require maintaining the furnace internal pressure at a positive pressure, there is no risk of the furnace gas leaking outside the furnace due to the introduction of inert gas, and various operations around the blast furnace can be carried out in parallel. It is possible to do so.
- FIG. 2 is a schematic cross-sectional view of the lower part of the blast furnace, showing a state in which a burner is inserted from the tap hole. It is a schematic diagram showing an example of a burner. FIG. 2 is a schematic cross-sectional view showing a state in which residual coke is combusted using a burner to reduce the volume of residual matter in the furnace.
- BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating one Embodiment of the furnace body of the blast furnace which implements the blast furnace operation method based on this invention. It is a graph showing the relationship between the amount of N 2 gas introduced into the furnace and the CO gas concentration in the furnace.
- FIG. 1 is a schematic cross-sectional view showing a part of the cross-section of the furnace body of a blast furnace.
- the blast furnace when the blast furnace is to be ventilated for a long period of time, the height of the surface of the raw material packed layer directly above the tuyere of the blast furnace is reduced from the upper end of the morning glory part of the blast furnace.
- FIG. 2 is a schematic cross-sectional view of the lower part of the blast furnace, showing a state in which the burner is inserted from the tap hole.
- the taphole is closed with a material called mud material when the blast furnace is not in operation. Open.
- a known taphole opening machine can be used to open the taphole. After the taphole opens, a burner is inserted into the lower part of the blast furnace through the taphole.
- FIGS. 3(a) and 3(b) are schematic diagrams each showing an example of a burner.
- the burner has a double tube structure including an inner tube and an outer tube through which gas flows, and a cap that covers the ends of the inner tube and the outer tube. , and a thermocouple provided outside the outer tube to measure the temperature of the burner.
- the cap is present as shown in FIG. 3(a)
- the gas blown from the gas inlet of the inner tube is discharged from the gas outlet of the outer tube without leaking to the outside.
- the cap is not present as shown in FIG. 3(b)
- the gas blown from the gas inlet of the inner tube is supplied into the furnace. Therefore, since the burner has a function of cooling the burner by flowing gas from the inner tube to the outer tube with the cap present, the burner can be stably inserted into the furnace.
- FIG. 4 is a schematic cross-sectional view showing a state in which the remaining coke is burned using a burner to reduce the volume of the remaining material in the furnace.
- FIG. 4 when coke disappears through combustion, more coke rolls into the space where the combustion disappeared according to the angle of repose, and as the coke sequentially burns and disappears, the volume of the remaining material in the furnace decreases. .
- a feature of the blast furnace operating method and blast furnace of the present invention is that it includes an introduction step of introducing an inert gas into the blast furnace after the above-mentioned air suspension and before the air blowing step.
- “after the wind rest and before the blowing process” means after the wind rest and (1) before the combustion process, (2) after the combustion process and before the charging process. (3) After the charging process and before the blowing process.
- (2) is preferred.
- the process is delayed because coke combustion may be inhibited.
- the temperature inside the furnace increases in step (2), which causes some of the unused coke charged in the charging process to react, which reduces the effect of the present invention. Decrease.
- inert gas is introduced into the blast furnace to suppress contact between the coke charged in the volume reduction area between the tuyere and the taphole and air. , inhibiting coke combustion.
- various inert gases such as argon and nitrogen can be used as the inert gas, but nitrogen (N 2 ) is optimal from the viewpoint of cost.
- FIG. 5 is a schematic diagram for explaining one embodiment of a furnace body of a blast furnace that implements the blast furnace operating method according to the present invention.
- the blast furnace is provided with piping serving as an inlet above the tuyeres, and inert gas is introduced into the blast furnace through this inlet.
- the inlet is provided directly above the tuyere, but it is located near the top of the blast furnace (for example, at a position approximately 5 m below the top of the blast furnace when the height of the blast furnace is 100 m).
- An inlet may be provided in the.
- inert gas By providing the introduction port above the tuyere, it is possible to prevent the introduction of the inert gas from being hindered by the coke charged in the volume reduction region between the tuyere and the taphole.
- inert gas By providing an inlet for introducing inert gas separately from other openings such as the raw material charging port, tuyere, and taphole, it is possible to , inert gas can be introduced without interfering with other operations or equipment.
- the amount of inert gas introduced into the blast furnace is determined by the volume of the blast furnace. Specifically, it is preferable to set the amount in a range of 7% or more and 13% or less per hour based on the volume of the blast furnace. This range is preferable because if the amount introduced is less than 7%, the amount is too small and it is difficult to suppress coke combustion, and even if the amount introduced is greater than 13%, the combustion suppression effect will not change. be.
- a determination step of determining whether or not combustion of coke in the blast furnace continues after the introduction step of introducing an inert gas into the blast furnace it is preferable to add a determination step of determining whether or not combustion of coke in the blast furnace continues after the introduction step of introducing an inert gas into the blast furnace.
- a gas analyzer is installed in a recovery pipe (not shown) that collects gas discharged from the furnace top, and this gas analyzer measures the gas concentration inside the furnace (gas concentration discharged from the furnace top). ) to analyze. If the concentration of CO gas is high (above the threshold value), it is determined that coke combustion continues, and if the concentration of CO gas is low (below the threshold value), it is determined that coke combustion continues. It is determined that the The CO gas concentration serving as the threshold value is, for example, 1%.
- FIG. 6 is a graph showing the relationship between the amount of N 2 gas introduced into the furnace and the CO gas concentration within the furnace.
- plots are omitted when the amount of N2 gas introduced is less than 7%, but when the amount of N2 gas introduced is less than 7%, the CO gas concentration is orders of magnitude higher than when it is 7% or more ( For example, 8% or more).
- the CO gas concentration was approximately 0.8% when the amount of N 2 gas introduced was 7%, and a sufficient decrease in the CO gas concentration was confirmed.
- the amount of N2 gas introduced was increased to 10%, resulting in a 25% increase in the amount of N2 gas introduced compared to the case where the amount of N2 gas introduced was 8%.
- the CO gas concentration decreased by 80% to around 0.1%, and the combustion consumption of coke could be sufficiently suppressed.
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Abstract
A blast-furnace operation method and a blast furnace are proposed with which it is possible to smoothly reoperate a blast furnace by preventing the coke from decreasing in diameter due to combustion and consumption and preventing the melt from deteriorating in dischargeability. The blast-furnace operation method is for suspending an operation of a blast furnace to stop the blasting and thereafter restarting blasting, and comprises a combustion step in which after the stopping of blasting, an oxygen-containing gas is blown into the furnace with a burner inserted into the tapping hole to burn the coke remaining in the furnace and reduce the volume of in-furnace residues, a charging step in which coke is newly charged into the volume reduction region, and a blasting step in which blasting through the tuyeres is restarted. The blast-furnace operation method further includes an introduction step in which an inert gas is introduced into the furnace during the period from after the stopping of blasting to before the blasting step.
Description
本発明は、操業を停止して高炉を休風し、その後、再度送風を開始するための高炉操業方法、および高炉操業方法に用いられる高炉に関する。
The present invention relates to a blast furnace operating method for stopping the operation, resting the blast furnace, and then restarting the blast furnace, and a blast furnace used in the blast furnace operating method.
従来、高炉操業は、火入れ以降定期的な設備補修を伴う短時間の停止を除き操業を止めることはなく、生産量を下げるなどの操業調整はすれども、操業自体は継続することが前提となっている。これは、操業停止に伴う再稼働コストが甚大であり経済合理性がないこと、および、一旦操業を停止すると再稼働まで半年程度の期間を要するため、生産量に対する上方弾力性がないことが挙げられる。
Traditionally, blast furnace operations have not stopped since firing, except for short-term shutdowns for periodic equipment repairs, and although operations have been adjusted such as reducing production, it has been assumed that operations will continue. ing. This is because the cost of restarting operations due to a shutdown is enormous and is not economically rational, and once operations are stopped, it takes about half a year to restart, so there is no upward elasticity with respect to production volume. It will be done.
一方、世界的に鉄鋼需要が一貫して高く増産基調であったこれまでとは異なり、現在の世界経済情勢は不安定であり、短期間に鉄鋼需要が大きく変化するようになった。これに伴い、高炉操業も大きな生産量の変動に対する柔軟性が求められるようになり、再度操業を可能な状態で停止するバンキングの重要性が高まっている。
On the other hand, unlike in the past when global steel demand was consistently high and production was increasing, the current global economic situation is unstable, and steel demand has changed significantly in a short period of time. Along with this, blast furnace operations are now required to be flexible to large fluctuations in production, and the importance of banking to shut down operations while it is possible to restart them is increasing.
高炉の改修を伴う停止においては、一定期間の停止を前提とするため、炉底部を解体して炉底部に溜まったコークス、溶銑および溶滓の除去を行うことが一般的である。一方、経済情勢次第で柔軟な再稼働を前提とするバンキングにおいては、当該作業は停止期間の延長を招くため実施しないことが望ましい。しかし、炉内残存物を除去しない場合、炉内の残存コークスは燃焼消費され小径化してしまい、空隙率の低下に伴い再稼働時の溶銑、溶滓の排出性を悪化させる。また、炉熱低下に伴い残存する溶銑・溶滓の流動性がそもそも悪化するため、排出作業を行わない場合は操業を再開した際に溶銑、溶滓の排出不良に陥る危険性が高く、最悪の場合には再稼働が不可能となっていた。
When a blast furnace is shut down due to renovation, it is assumed that the blast furnace will be shut down for a certain period of time, so it is common to dismantle the bottom of the furnace and remove the coke, hot metal, and slag that have accumulated at the bottom of the furnace. On the other hand, in banking, which assumes flexible restarts depending on the economic situation, it is preferable not to carry out such work as it will extend the suspension period. However, if the residual material in the furnace is not removed, the residual coke in the furnace will be consumed by combustion and become smaller in diameter, resulting in a decrease in porosity and worsening of the discharge of hot metal and slag upon restart. In addition, the fluidity of the remaining hot metal and slag deteriorates as the furnace heat decreases, so if discharge work is not performed, there is a high risk that the hot metal and slag will not be properly discharged when operations are resumed. In such cases, restarting operations was impossible.
上述した課題に対し、例えば特許文献１では、補修作業に支障が出ることを防止する目的で炉内に投入する不燃物を低融点組成のものとすることで、再稼働時の排出性の悪化抑止を図っていた。また、特許文献２では、残存コークスの燃焼消費による小径化だけでなく、当該コークスに付着している銑鉄・スラグ等が再稼働時に再溶解し溶融物の量の増大を招くことを見出した結果、当該コークスを、バーナを利用して意図的に燃焼消失させた後に、新たなコークスを装入することで再稼働時の溶融物の量の増大を防いでいた。
In response to the above-mentioned problems, for example, in Patent Document 1, in order to prevent troubles in repair work, the incombustible materials introduced into the furnace have a low melting point composition, thereby deteriorating the discharge performance when restarting the furnace. He was trying to deter him. In addition, in Patent Document 2, it was found that not only the remaining coke is reduced in diameter due to combustion consumption, but also that the pig iron, slag, etc. attached to the coke are remelted when restarting operations, leading to an increase in the amount of molten material. After the coke was intentionally burnt out using a burner, new coke was charged to prevent the amount of molten material from increasing when restarting the plant.
しかしながら、特許文献１では、そもそも操業再開に伴い生成する炉内スラグに加えて低融点不燃物を系外から投入しており、排出しなければならない溶滓量の増大を招く点で、依然として課題が残っていた。また、特許文献２は、従来技術と比較し、溶融物の量の増大を抑止している点で先進性があるが、装入した新たなコークスの燃焼による小径化自体は防ぐことができておらず、バンキングが長期間になるほどコークスの燃焼消費による小径化およびそれに伴う排出性の悪化は避けられない点に課題があった。
However, in Patent Document 1, in addition to the in-furnace slag that is generated upon resumption of operation, low-melting point incombustibles are injected from outside the system, which still poses a problem in that it leads to an increase in the amount of slag that must be discharged. was left. Additionally, Patent Document 2 is more advanced in that it suppresses the increase in the amount of molten material compared to the conventional technology, but it does not prevent diameter reduction itself due to combustion of newly charged coke. However, the problem was that the longer the banking period, the smaller the diameter due to the combustion consumption of coke and the accompanying deterioration in emissions.
本発明の目的は、先行特許において為しえていなかったコークスの燃焼消費による小径化を抑止し、溶融物の排出性の悪化を防ぐことで高炉の再稼働を円滑に行うことができる、高炉操業方法および高炉を提案することにある。
The purpose of the present invention is to suppress the reduction in diameter due to the combustion consumption of coke, which could not be achieved in the previous patent, and to prevent the deterioration of the discharge performance of the molten material, thereby enabling smooth restart of the blast furnace. The aim is to propose operating methods and blast furnaces.
本発明の高炉操業方法は、前述の課題を解決すべく開発されたものであり、操業を停止して高炉を休風し、その後、再度送風を開始するための高炉操業方法であって、休風後に出銑口に挿入したバーナより、酸素含有ガスを吹き込み、炉内に残存したコークスを燃焼させて炉内残存物の体積を低減させる燃焼工程と、当該体積減少領域に新たにコークスを装入する装入工程と、羽口からの送風を再開する送風工程と、を有する高炉操業方法において、前記休風の後であって前記送風工程の前までに、炉内に不活性ガスを導入する導入工程を有する、高炉操業方法である。
The blast furnace operating method of the present invention was developed to solve the above-mentioned problems, and is a blast furnace operating method for stopping the operation, taking a break from the blast furnace, and then restarting the blast furnace. A combustion process involves blowing oxygen-containing gas through a burner inserted into the taphole after the wind has finished, and burning the coke remaining in the furnace to reduce the volume of the remaining material in the furnace, and adding new coke to the volume reduction area. In a method for operating a blast furnace, the method includes a charging step in which air is introduced into the furnace, and a blowing step in which air is restarted from the tuyeres. This is a blast furnace operating method that includes an introduction step.
なお、前記のように構成される本発明に係る高炉操業方法においては、
（１）前記導入工程後、高炉内のコークスの燃焼が継続しているか否かを判定する判定工程をさらに有すること、
（２）前記判定工程では、高炉内のガスの濃度を分析し、ＣＯガスの濃度が閾値以上の場合に高炉内のコークスの燃焼が継続していると判定すること、
（３）前記判定工程において、高炉内のコークスの燃焼が継続していると判定された場合に、羽口上部まで追加でコークスを装入する追加工程をさらに有すること、
（４）前記導入工程において、高炉内に導入される不活性ガスの量は、１時間当たり高炉容積に対して７％以上１３％以下の範囲であること、
（５）前記導入工程において不活性ガスは、高炉の羽口より上部に形成された導入口から高炉内に導入されること、
がより好ましい解決手段となるものと考えられる。 In addition, in the blast furnace operating method according to the present invention configured as described above,
(1) further comprising a determination step of determining whether or not combustion of coke in the blast furnace continues after the introduction step;
(2) In the determination step, the concentration of gas in the blast furnace is analyzed, and if the concentration of CO gas is equal to or higher than a threshold value, determining that the combustion of coke in the blast furnace continues;
(3) further comprising an additional step of charging additional coke up to the upper part of the tuyere when it is determined in the determination step that the combustion of coke in the blast furnace continues;
(4) In the introduction step, the amount of inert gas introduced into the blast furnace is in the range of 7% to 13% of the blast furnace volume per hour;
(5) In the introduction step, the inert gas is introduced into the blast furnace through an inlet formed above the tuyere of the blast furnace;
is considered to be a more preferable solution.
（１）前記導入工程後、高炉内のコークスの燃焼が継続しているか否かを判定する判定工程をさらに有すること、
（２）前記判定工程では、高炉内のガスの濃度を分析し、ＣＯガスの濃度が閾値以上の場合に高炉内のコークスの燃焼が継続していると判定すること、
（３）前記判定工程において、高炉内のコークスの燃焼が継続していると判定された場合に、羽口上部まで追加でコークスを装入する追加工程をさらに有すること、
（４）前記導入工程において、高炉内に導入される不活性ガスの量は、１時間当たり高炉容積に対して７％以上１３％以下の範囲であること、
（５）前記導入工程において不活性ガスは、高炉の羽口より上部に形成された導入口から高炉内に導入されること、
がより好ましい解決手段となるものと考えられる。 In addition, in the blast furnace operating method according to the present invention configured as described above,
(1) further comprising a determination step of determining whether or not combustion of coke in the blast furnace continues after the introduction step;
(2) In the determination step, the concentration of gas in the blast furnace is analyzed, and if the concentration of CO gas is equal to or higher than a threshold value, determining that the combustion of coke in the blast furnace continues;
(3) further comprising an additional step of charging additional coke up to the upper part of the tuyere when it is determined in the determination step that the combustion of coke in the blast furnace continues;
(4) In the introduction step, the amount of inert gas introduced into the blast furnace is in the range of 7% to 13% of the blast furnace volume per hour;
(5) In the introduction step, the inert gas is introduced into the blast furnace through an inlet formed above the tuyere of the blast furnace;
is considered to be a more preferable solution.
また、本発明の高炉は、上述した高炉操業方法を実施する高炉であって、不活性ガスを導入するための導入口が羽口より上部に形成されている、高炉である。
Further, the blast furnace of the present invention is a blast furnace that implements the above-described blast furnace operating method, and is a blast furnace in which an inlet for introducing inert gas is formed above the tuyere.
本発明の高炉操業方法および高炉によれば、高炉内に不活性ガスを導入することで、高炉内においてコークスの燃焼消費による小径化を抑止することができる。これにより、溶融物の排出性の悪化を防ぐことで高炉の再稼働を円滑に行うことができる。また、本発明は炉内圧を陽圧に保つことを必要としないため、不活性ガスの導入に伴う炉内ガスの炉外への漏洩リスクがなく、高炉周辺での種々の作業を並行して行うことが可能である。
According to the blast furnace operating method and blast furnace of the present invention, by introducing an inert gas into the blast furnace, it is possible to prevent diameter reduction due to combustion consumption of coke in the blast furnace. Thereby, the blast furnace can be restarted smoothly by preventing deterioration in the discharge performance of the molten material. Furthermore, since the present invention does not require maintaining the furnace internal pressure at a positive pressure, there is no risk of the furnace gas leaking outside the furnace due to the introduction of inert gas, and various operations around the blast furnace can be carried out in parallel. It is possible to do so.
以下、本発明の実施の形態について具体的に説明する。なお、以下の実施形態は、本発明の技術的思想を具体化するための装置や方法を例示するものであり、構成を下記のものに特定するものでない。すなわち、本発明の技術的思想は、特許請求の範囲に記載された技術的範囲内において、種々の変更を加えることができる。
Hereinafter, embodiments of the present invention will be specifically described. Note that the following embodiments are intended to exemplify an apparatus and method for embodying the technical idea of the present invention, and the configuration is not limited to the following. That is, the technical idea of the present invention can be modified in various ways within the technical scope described in the claims.
＜本発明の対象となる高炉操業方法および高炉の一例について＞
図１は、高炉の炉体断面の一部を示す断面模式図である。図１に示す実施形態において、高炉を長期間休風する場合、高炉の羽口直上の原料充填層表面の高さを高炉の朝顔部の上端よりも減じて休風する。その後、羽口からの送風を再開して高炉を通常操業に戻すには、まず、出銑口から炉内にバーナを挿入し、バーナから酸素含有ガスまたは酸素含有ガスおよび可燃ガスを吹き込み、炉内に残存したコークスを燃焼させて炉内残存物の体積を減少させる（燃焼工程）。 <About an example of the blast furnace operating method and blast furnace that are the subject of the present invention>
FIG. 1 is a schematic cross-sectional view showing a part of the cross-section of the furnace body of a blast furnace. In the embodiment shown in FIG. 1, when the blast furnace is to be ventilated for a long period of time, the height of the surface of the raw material packed layer directly above the tuyere of the blast furnace is reduced from the upper end of the morning glory part of the blast furnace. After that, in order to restart the air blowing from the tuyere and return the blast furnace to normal operation, first insert a burner into the furnace through the taphole, blow oxygen-containing gas or oxygen-containing gas and combustible gas from the burner, and then The volume of the remaining material in the furnace is reduced by burning the coke remaining in the furnace (combustion process).
図１は、高炉の炉体断面の一部を示す断面模式図である。図１に示す実施形態において、高炉を長期間休風する場合、高炉の羽口直上の原料充填層表面の高さを高炉の朝顔部の上端よりも減じて休風する。その後、羽口からの送風を再開して高炉を通常操業に戻すには、まず、出銑口から炉内にバーナを挿入し、バーナから酸素含有ガスまたは酸素含有ガスおよび可燃ガスを吹き込み、炉内に残存したコークスを燃焼させて炉内残存物の体積を減少させる（燃焼工程）。 <About an example of the blast furnace operating method and blast furnace that are the subject of the present invention>
FIG. 1 is a schematic cross-sectional view showing a part of the cross-section of the furnace body of a blast furnace. In the embodiment shown in FIG. 1, when the blast furnace is to be ventilated for a long period of time, the height of the surface of the raw material packed layer directly above the tuyere of the blast furnace is reduced from the upper end of the morning glory part of the blast furnace. After that, in order to restart the air blowing from the tuyere and return the blast furnace to normal operation, first insert a burner into the furnace through the taphole, blow oxygen-containing gas or oxygen-containing gas and combustible gas from the burner, and then The volume of the remaining material in the furnace is reduced by burning the coke remaining in the furnace (combustion process).
図２は、出銑口からバーナを挿入した状態を示す高炉炉下部の断面模式図である。図２に示す実施形態において、高炉休風時において出銑口はマッド材と呼ばれる材質で閉塞されているので、バーナを炉内に挿入するために、まず、マッド材で閉塞された出銑口を開口する。出銑口の開口には、公知の出銑口開口機を用いることができる。出銑口が開口した後、出銑口から高炉炉下部にバーナが挿入される。
FIG. 2 is a schematic cross-sectional view of the lower part of the blast furnace, showing a state in which the burner is inserted from the tap hole. In the embodiment shown in Fig. 2, the taphole is closed with a material called mud material when the blast furnace is not in operation. Open. A known taphole opening machine can be used to open the taphole. After the taphole opens, a burner is inserted into the lower part of the blast furnace through the taphole.
図３（ａ）、（ｂ）は、それぞれバーナの一例を示す模式図である。図３（ａ）、（ｂ）に示す実施形態において、バーナは、気体が流通する内管と外管との２重管構造を有するとともに、内管と外管との端部を覆うキャップと、外管外部に設けられてバーナの温度を測定する熱電対と、を有している。図３（ａ）に示すようにキャップが存在する場合は、内管の気体導入口から吹き込んだ気体が外部に漏れずに外管の気体排出口から排出される。一方、図３（ｂ）に示すようにキャップが存在しない場合は、内管の気体導入口から吹き込んだ気体が炉内に供給される。そのため、バーナは、キャップを存在させた状態で内管から外管に気体を流してバーナを冷却する機能を有するため、安定してバーナを炉内に挿入することができる。
FIGS. 3(a) and 3(b) are schematic diagrams each showing an example of a burner. In the embodiment shown in FIGS. 3(a) and 3(b), the burner has a double tube structure including an inner tube and an outer tube through which gas flows, and a cap that covers the ends of the inner tube and the outer tube. , and a thermocouple provided outside the outer tube to measure the temperature of the burner. When the cap is present as shown in FIG. 3(a), the gas blown from the gas inlet of the inner tube is discharged from the gas outlet of the outer tube without leaking to the outside. On the other hand, if the cap is not present as shown in FIG. 3(b), the gas blown from the gas inlet of the inner tube is supplied into the furnace. Therefore, since the burner has a function of cooling the burner by flowing gas from the inner tube to the outer tube with the cap present, the burner can be stably inserted into the furnace.
また、燃焼開始時には、内管から外管の気体の流通による冷却を止め、炉熱等によってキャップを溶解させて除去し、例えばバーナの内管から炉内に可燃ガスを吹き込み、外管から支燃性ガスとして酸素含有ガスを炉下部に吹き込む。バーナ先端部の温度が、周囲に存在するコークスの燃焼開始温度（概ね８００℃）を超えたら、バーナから吹き込むガスを酸素含有ガスのみに切り替えてコークスを燃焼させる。酸素含有ガスとしては純酸素を吹き込むことが好ましいが、コークスの燃焼が持続できれば酸素濃度が１００％よりも低いガスでもよい。なお、本実施形態では、バーナから可燃性ガスと酸素含有ガスとを吹き込む例を示したが、これに限らず、バーナから酸素含有ガスのみを吹き込んでもよい。
In addition, at the start of combustion, cooling by gas flow from the inner tube to the outer tube is stopped, the cap is melted and removed by furnace heat, etc., and combustible gas is blown into the furnace from the inner tube of the burner, and the cap is supported from the outer tube. Oxygen-containing gas is blown into the lower part of the furnace as a combustible gas. When the temperature at the tip of the burner exceeds the combustion start temperature of surrounding coke (approximately 800° C.), the gas blown from the burner is switched to only oxygen-containing gas to burn the coke. It is preferable to blow pure oxygen as the oxygen-containing gas, but a gas with an oxygen concentration lower than 100% may be used as long as the combustion of coke can be sustained. In this embodiment, an example was shown in which combustible gas and oxygen-containing gas are blown from the burner, but the present invention is not limited to this, and only oxygen-containing gas may be blown from the burner.
図４は、バーナを用いて残存コークスを燃焼させて炉内残存物の体積を減少させた状態を示す断面模式図である。図４に示す実施形態において、燃焼によりコークスが消失すると、その燃焼消失した空間にさらに安息角に応じてコークスが転がり込み、コークスが順次燃焼消失することで、炉内残存物の体積が減少する。
FIG. 4 is a schematic cross-sectional view showing a state in which the remaining coke is burned using a burner to reduce the volume of the remaining material in the furnace. In the embodiment shown in FIG. 4, when coke disappears through combustion, more coke rolls into the space where the combustion disappeared according to the angle of repose, and as the coke sequentially burns and disappears, the volume of the remaining material in the furnace decreases. .
その後、バーナからの酸素の吹き込みを停止して、炉内残存物の体積を低減させることによって炉内に生じた空間である体積減少領域へ高炉上部から未使用のコークスを装入して充填した（装入工程）。そして、再びバーナから酸素を吹き込んで新規に充填されたコークスを加熱し、羽口先端部のコークスの温度が例えば２０００℃ を超えた時点で、羽口から例えば１１００℃の熱風を送風し（送風工程）、羽口からの加熱に切り替えて高炉を立ち上げる。
After that, the blowing of oxygen from the burner was stopped, and unused coke was charged from the top of the blast furnace into the volume reduction area, which is the space created in the furnace by reducing the volume of the remaining material in the furnace. (Charging process). Oxygen is then blown from the burner again to heat the newly filled coke, and when the temperature of the coke at the tip of the tuyere exceeds, for example, 2,000°C, hot air of, for example, 1,100°C is blown from the tuyere. process), switch to heating from the tuyeres and start up the blast furnace.
＜本発明の高炉操業方法および高炉の特徴について＞
本発明の高炉操業方法および高炉の特徴は、上述した休風の後であって送風工程の前までに、高炉内に不活性ガスを導入する導入工程を有する点にある。ここで、「休風の後であって送風工程の前までに」とは、休風後であって（１）燃焼工程の前の時点、（２）燃焼工程後であって装入工程の前の時点、（３）装入工程後であって送風工程の前の時点、のうちのいずれかの時点を意味する。このうち、好適なのは（２）である。（１）で不活性ガスを導入する場合、コークス燃焼が阻害されうるため工程が遅延する。（３）で不活性ガスを導入する場合、（２）で炉内温度が上昇することで装入工程にて装入した未使用のコークスが一部反応してしまうため、本発明の効果が減少する。 <About the blast furnace operating method and characteristics of the blast furnace of the present invention>
A feature of the blast furnace operating method and blast furnace of the present invention is that it includes an introduction step of introducing an inert gas into the blast furnace after the above-mentioned air suspension and before the air blowing step. Here, "after the wind rest and before the blowing process" means after the wind rest and (1) before the combustion process, (2) after the combustion process and before the charging process. (3) After the charging process and before the blowing process. Among these, (2) is preferred. When introducing an inert gas in (1), the process is delayed because coke combustion may be inhibited. When introducing an inert gas in step (3), the temperature inside the furnace increases in step (2), which causes some of the unused coke charged in the charging process to react, which reduces the effect of the present invention. Decrease.
本発明の高炉操業方法および高炉の特徴は、上述した休風の後であって送風工程の前までに、高炉内に不活性ガスを導入する導入工程を有する点にある。ここで、「休風の後であって送風工程の前までに」とは、休風後であって（１）燃焼工程の前の時点、（２）燃焼工程後であって装入工程の前の時点、（３）装入工程後であって送風工程の前の時点、のうちのいずれかの時点を意味する。このうち、好適なのは（２）である。（１）で不活性ガスを導入する場合、コークス燃焼が阻害されうるため工程が遅延する。（３）で不活性ガスを導入する場合、（２）で炉内温度が上昇することで装入工程にて装入した未使用のコークスが一部反応してしまうため、本発明の効果が減少する。 <About the blast furnace operating method and characteristics of the blast furnace of the present invention>
A feature of the blast furnace operating method and blast furnace of the present invention is that it includes an introduction step of introducing an inert gas into the blast furnace after the above-mentioned air suspension and before the air blowing step. Here, "after the wind rest and before the blowing process" means after the wind rest and (1) before the combustion process, (2) after the combustion process and before the charging process. (3) After the charging process and before the blowing process. Among these, (2) is preferred. When introducing an inert gas in (1), the process is delayed because coke combustion may be inhibited. When introducing an inert gas in step (3), the temperature inside the furnace increases in step (2), which causes some of the unused coke charged in the charging process to react, which reduces the effect of the present invention. Decrease.
本発明の高炉操業方法では、導入工程において、高炉内に不活性ガスを導入することで、羽口と出銑口との間の体積減少領域に装入したコークスと空気との接触を抑制し、コークスの燃焼を抑止する。なお、不活性ガスとしては、アルゴンや窒素などの各種の不活性ガスを用いることができるが、コストの観点から窒素（Ｎ２）が最適である。
In the blast furnace operating method of the present invention, in the introduction step, inert gas is introduced into the blast furnace to suppress contact between the coke charged in the volume reduction area between the tuyere and the taphole and air. , inhibiting coke combustion. Note that various inert gases such as argon and nitrogen can be used as the inert gas, but nitrogen (N 2 ) is optimal from the viewpoint of cost.
図５は、本発明に係る高炉操業方法を実施する高炉の炉体の一実施形態を説明するための模式図である。図５に示すように、高炉には、羽口より上部に導入口となる配管が設けられており、この導入口から高炉内に不活性ガスが導入される。なお、図５に示す例では、羽口の直上に導入口が設けられているが、高炉の炉頂付近（例えば高炉高さを１００ｍとした場合に高炉の炉頂から５ｍ程度下の位置）に導入口を設けてもよい。導入口を羽口より上部に設けることで、羽口と出銑口との間の体積減少領域に装入したコークスによって不活性ガスの導入が妨げられることを抑制することができる。また、不活性ガスを導入するための導入口を原料装入口や羽口、出銑口などの他の開口部とは別に設けることで、他の開口部から不活性ガスを導入する構成に比べ、他の作業や設備に干渉することなく不活性ガスの導入作業を行うことができる。
FIG. 5 is a schematic diagram for explaining one embodiment of a furnace body of a blast furnace that implements the blast furnace operating method according to the present invention. As shown in FIG. 5, the blast furnace is provided with piping serving as an inlet above the tuyeres, and inert gas is introduced into the blast furnace through this inlet. In the example shown in Fig. 5, the inlet is provided directly above the tuyere, but it is located near the top of the blast furnace (for example, at a position approximately 5 m below the top of the blast furnace when the height of the blast furnace is 100 m). An inlet may be provided in the. By providing the introduction port above the tuyere, it is possible to prevent the introduction of the inert gas from being hindered by the coke charged in the volume reduction region between the tuyere and the taphole. In addition, by providing an inlet for introducing inert gas separately from other openings such as the raw material charging port, tuyere, and taphole, it is possible to , inert gas can be introduced without interfering with other operations or equipment.
ここで、高炉内に導入される不活性ガスの導入量は、高炉の容積によって定まる。具体的には、高炉の容積に対して１時間当たり７％以上１３％以下の範囲とすることが好ましい。この範囲が好ましいのは、導入量が７％未満の場合は、量が少なすぎてコークスの燃焼を抑止することが難しく、導入量を１３％より大きくしても燃焼抑制効果は変わらないからである。
Here, the amount of inert gas introduced into the blast furnace is determined by the volume of the blast furnace. Specifically, it is preferable to set the amount in a range of 7% or more and 13% or less per hour based on the volume of the blast furnace. This range is preferable because if the amount introduced is less than 7%, the amount is too small and it is difficult to suppress coke combustion, and even if the amount introduced is greater than 13%, the combustion suppression effect will not change. be.
なお、本発明の高炉操業方法では、高炉内に不活性ガスを導入する導入工程の後に、高炉内のコークスの燃焼が継続しているか否かを判定する判定工程を追加することが好ましい。具体的には、炉頂から排出されるガスを回収する回収管（図示省略）にガス分析計が設置されており、このガス分析計によって炉内のガス濃度（炉頂から排出されるガス濃度）を分析する。そして、ＣＯガスの濃度が高い場合（閾値以上の場合）は、コークスの燃焼が継続していると判定し、ＣＯガスの濃度が低い場合（閾値未満の場合）は、コークスの燃焼が継続していないと判定する。閾値となるＣＯガス濃度は、例えば１％である。
In addition, in the blast furnace operating method of the present invention, it is preferable to add a determination step of determining whether or not combustion of coke in the blast furnace continues after the introduction step of introducing an inert gas into the blast furnace. Specifically, a gas analyzer is installed in a recovery pipe (not shown) that collects gas discharged from the furnace top, and this gas analyzer measures the gas concentration inside the furnace (gas concentration discharged from the furnace top). ) to analyze. If the concentration of CO gas is high (above the threshold value), it is determined that coke combustion continues, and if the concentration of CO gas is low (below the threshold value), it is determined that coke combustion continues. It is determined that the The CO gas concentration serving as the threshold value is, for example, 1%.
また、判定工程において、コークスの燃焼が継続していると判定した場合は、さらに羽口上部まで追加でコークスを装入することで、炉内に残存している酸素と、追加した羽口より上部のコークスとを反応させる（燃焼させる）ことが好ましい。これにより、羽口と出銑口との間に存在するコークスの燃焼消費を抑止することができ、羽口と出銑口との間のコークスの小径化、およびそれに伴う排出性の悪化を避けることができる。
In addition, if it is determined that coke combustion continues in the determination process, additional coke is charged up to the top of the tuyere to remove oxygen remaining in the furnace and from the added tuyere. It is preferable to react (burn) the upper coke. This can suppress the combustion consumption of coke existing between the tuyere and taphole, and avoid reducing the diameter of coke between the tuyere and taphole and the associated deterioration in discharge performance. be able to.
上述した実施形態に従って、実際に、内容積が５０００ｍ３の高炉を用い、炉内へ導入量を変えてＮ２ガスを導入して、炉内のＣＯガス濃度の変化を求めた。図６は、炉内へのＮ２ガス導入量と炉内のＣＯガス濃度との関係を示すグラフである。なお、図６に示すグラフにおいて、Ｎ２ガス導入量が７％未満についてはプロットを省略しているが、７％未満では７％以上の場合に比べてＣＯガス濃度が桁違いに多くなる（例えば８％以上になる）。実施例においては、Ｎ２ガス導入量７％でＣＯガス濃度が０．８％程度となり、十分なＣＯガス濃度の低下が確認された。さらに、コークスの燃焼消費を徹底的に抑制する目的でＮ２ガス導入量を１０％まで増量した結果、Ｎ２ガス導入量８％の場合と比較して、Ｎ２ガス導入量が２５％増になった一方で、ＣＯガス濃度は８０％減の０．１％程度まで低下し、十分コークスの燃焼消費を抑えることが出来た。本発明を用いることで、高炉立ち上げ時の溶融物の排出性の確保が可能となり、炉内残存物を除去することなく再稼働後、２１日で工程操業へ復帰できた。
According to the embodiment described above, a blast furnace with an internal volume of 5000 m 3 was actually used, and N 2 gas was introduced into the furnace at varying amounts to determine changes in the CO gas concentration inside the furnace. FIG. 6 is a graph showing the relationship between the amount of N 2 gas introduced into the furnace and the CO gas concentration within the furnace. In the graph shown in Figure 6, plots are omitted when the amount of N2 gas introduced is less than 7%, but when the amount of N2 gas introduced is less than 7%, the CO gas concentration is orders of magnitude higher than when it is 7% or more ( For example, 8% or more). In the example, the CO gas concentration was approximately 0.8% when the amount of N 2 gas introduced was 7%, and a sufficient decrease in the CO gas concentration was confirmed. Furthermore, in order to thoroughly suppress coke combustion consumption, the amount of N2 gas introduced was increased to 10%, resulting in a 25% increase in the amount of N2 gas introduced compared to the case where the amount of N2 gas introduced was 8%. On the other hand, the CO gas concentration decreased by 80% to around 0.1%, and the combustion consumption of coke could be sufficiently suppressed. By using the present invention, it became possible to ensure the discharge of molten material at the time of startup of the blast furnace, and it was possible to return to process operation within 21 days after restarting the blast furnace without removing the remaining materials in the furnace.
According to the embodiment described above, a blast furnace with an internal volume of 5000 m 3 was actually used, and N 2 gas was introduced into the furnace at varying amounts to determine changes in the CO gas concentration inside the furnace. FIG. 6 is a graph showing the relationship between the amount of N 2 gas introduced into the furnace and the CO gas concentration within the furnace. In the graph shown in Figure 6, plots are omitted when the amount of N2 gas introduced is less than 7%, but when the amount of N2 gas introduced is less than 7%, the CO gas concentration is orders of magnitude higher than when it is 7% or more ( For example, 8% or more). In the example, the CO gas concentration was approximately 0.8% when the amount of N 2 gas introduced was 7%, and a sufficient decrease in the CO gas concentration was confirmed. Furthermore, in order to thoroughly suppress coke combustion consumption, the amount of N2 gas introduced was increased to 10%, resulting in a 25% increase in the amount of N2 gas introduced compared to the case where the amount of N2 gas introduced was 8%. On the other hand, the CO gas concentration decreased by 80% to around 0.1%, and the combustion consumption of coke could be sufficiently suppressed. By using the present invention, it became possible to ensure the discharge of molten material at the time of startup of the blast furnace, and it was possible to return to process operation within 21 days after restarting the blast furnace without removing the remaining materials in the furnace.
Claims (7)
- 操業を停止して高炉を休風し、その後、再度送風を開始するための高炉操業方法であって、休風後に出銑口に挿入したバーナより、酸素含有ガスを吹き込み、炉内に残存したコークスを燃焼させて炉内残存物の体積を低減させる燃焼工程と、当該体積減少領域に新たにコークスを装入する装入工程と、羽口からの送風を再開する送風工程と、を有する高炉操業方法において、前記休風の後であって前記送風工程の前までに、炉内に不活性ガスを導入する導入工程を有する、高炉操業方法。 This is a method of operating a blast furnace in which the blast furnace is shut down, the blast furnace is given a break, and then the blast furnace is restarted. A blast furnace that has a combustion step of burning coke to reduce the volume of the remaining material in the furnace, a charging step of newly charging coke into the volume reduction area, and a blowing step of restarting air blowing from the tuyeres. A blast furnace operating method comprising an introduction step of introducing an inert gas into the furnace after the air rest and before the air blowing step.
- 前記導入工程後、高炉内のコークスの燃焼が継続しているか否かを判定する判定工程をさらに有する、請求項１に記載の高炉操業方法。 The blast furnace operating method according to claim 1, further comprising a determination step of determining whether or not combustion of coke in the blast furnace continues after the introduction step.
- 前記判定工程では、高炉内のガスの濃度を分析し、ＣＯガスの濃度が閾値以上の場合に高炉内のコークスの燃焼が継続していると判定する、請求項２に記載の高炉操業方法。 The blast furnace operating method according to claim 2, wherein in the determination step, the concentration of gas in the blast furnace is analyzed, and if the concentration of CO gas is equal to or higher than a threshold value, it is determined that combustion of coke in the blast furnace continues.
- 前記判定工程において、高炉内のコークスの燃焼が継続していると判定された場合に、羽口上部まで追加でコークスを装入する追加工程をさらに有する、請求項２または３に記載の高炉操業方法。 The blast furnace operation according to claim 2 or 3, further comprising an additional step of charging coke up to the upper part of the tuyere when it is determined in the determination step that combustion of coke in the blast furnace continues. Method.
- 前記導入工程において、高炉内に導入される不活性ガスの量は、１時間当たり高炉容積に対して７％以上１３％以下の範囲である、請求項１に記載の高炉操業方法。 The blast furnace operating method according to claim 1, wherein in the introduction step, the amount of inert gas introduced into the blast furnace is in the range of 7% or more and 13% or less based on the blast furnace volume per hour.
- 前記導入工程において不活性ガスは、高炉の羽口より上部に形成された導入口から高炉内に導入される、請求項１に記載の高炉操業方法。 The blast furnace operating method according to claim 1, wherein in the introduction step, the inert gas is introduced into the blast furnace from an inlet formed above the tuyere of the blast furnace.
- 請求項１に記載の高炉操業方法を実施する高炉であって、不活性ガスを導入するための導入口が羽口より上部に形成されている、高炉。
A blast furnace for carrying out the blast furnace operating method according to claim 1, wherein an inlet for introducing an inert gas is formed above the tuyere.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5271307A (en) * | 1975-12-11 | 1977-06-14 | Nippon Steel Corp | Shutdown of blast furnace |
| JPS53138913A (en) * | 1977-05-10 | 1978-12-04 | Nippon Steel Corp | Reblowing-in method for blast furnace being out of operation |
| JP6947345B1 (en) * | 2020-05-15 | 2021-10-13 | Ｊｆｅスチール株式会社 | Blast furnace operation method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5271307A (en) * | 1975-12-11 | 1977-06-14 | Nippon Steel Corp | Shutdown of blast furnace |
| JPS53138913A (en) * | 1977-05-10 | 1978-12-04 | Nippon Steel Corp | Reblowing-in method for blast furnace being out of operation |
| JP6947345B1 (en) * | 2020-05-15 | 2021-10-13 | Ｊｆｅスチール株式会社 | Blast furnace operation method |
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