WO2024171511A1 - Blast furnace operation method - Google Patents
Blast furnace operation method Download PDFInfo
- Publication number
- WO2024171511A1 WO2024171511A1 PCT/JP2023/036755 JP2023036755W WO2024171511A1 WO 2024171511 A1 WO2024171511 A1 WO 2024171511A1 JP 2023036755 W JP2023036755 W JP 2023036755W WO 2024171511 A1 WO2024171511 A1 WO 2024171511A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- blast furnace
- gas
- coke
- oxygen
- reducing agent
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 18
- 239000007789 gas Substances 0.000 claims abstract description 80
- 239000000571 coke Substances 0.000 claims abstract description 43
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 39
- 239000001301 oxygen Substances 0.000 claims abstract description 39
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 39
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000004215 Carbon black (E152) Substances 0.000 claims abstract description 21
- 229930195733 hydrocarbon Natural products 0.000 claims abstract description 21
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract description 21
- 230000009257 reactivity Effects 0.000 claims abstract description 18
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000001257 hydrogen Substances 0.000 claims abstract description 14
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 14
- 229910052742 iron Inorganic materials 0.000 claims abstract description 13
- 239000002994 raw material Substances 0.000 claims abstract description 6
- 150000001875 compounds Chemical class 0.000 claims abstract description 4
- 239000003638 chemical reducing agent Substances 0.000 claims description 54
- 239000000463 material Substances 0.000 abstract description 5
- 238000007664 blowing Methods 0.000 abstract description 4
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 239000000126 substance Substances 0.000 abstract 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 22
- 238000006243 chemical reaction Methods 0.000 description 15
- 239000003245 coal Substances 0.000 description 12
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 10
- 238000002309 gasification Methods 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 238000003723 Smelting Methods 0.000 description 5
- 229910002092 carbon dioxide Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 229910000805 Pig iron Inorganic materials 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 229920003023 plastic Polymers 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 2
- AFCARXCZXQIEQB-UHFFFAOYSA-N N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CCNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 AFCARXCZXQIEQB-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- -1 ethylene, propylene, methanol Chemical class 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B5/00—Making pig-iron in the blast furnace
Definitions
- the present invention relates to a method for operating a blast furnace that can reduce the reducing agent ratio during blast furnace operation.
- iron-based raw materials and coke are charged in layers from the top of the furnace, and hot air (high-temperature air) and reducing agents such as pulverized coal are blown in from tuyeres at the bottom of the furnace.
- hot air high-temperature air
- reducing agents such as pulverized coal
- reducing agents such as coke and pulverized coal are used to reduce the iron source in the furnace.
- the total weight of reducing agents required to produce one ton of pig iron is called the reducing agent ratio. If the reducing agent ratio can be reduced, CO2 emissions from the blast furnace and the production costs of pig iron can be reduced. Therefore, reducing the reducing agent ratio is an important issue in blast furnace operation, and many technical developments have been carried out.
- Patent Document 1 and Patent Document 2 there is a technique for reducing the reducing agent ratio by using highly reactive coke.
- Ferro coke is well known as a representative example of highly reactive coke.
- Ferro coke is produced by mixing coal with iron ore powder and carbonizing it, and the Fe contained within the coke acts as a catalyst for the gasification reaction of the coke, increasing its reactivity.
- Patent Document 3, Patent Document 4, and Non-Patent Document 1 state that the reducing agent ratio can be reduced by using ferro coke.
- Blast furnaces which emit large amounts of CO2 , are no exception.
- Patent Document 5 a blast furnace in which an oxygen-containing gas with a concentration close to 100% is blown from the tuyere as a blast gas and methane is blown in as a reducing agent is being considered.
- This blast furnace is different from conventional general blast furnaces in that a high-concentration oxygen-containing gas is blown from the tuyere instead of hot air, and a large amount of methane is blown in instead of pulverized coal as a reducing agent from the tuyere, and the operating conditions have changed significantly.
- Patent Document 6 discloses that when injecting a large amount of hydrogen-containing gas, including hydrogen gas, into a blast furnace, it is effective to reduce the reactivity of the coke in order to suppress the endothermic heat caused by the gasification reaction of the coke.
- Patent Document 6 targets blast furnaces that blow hot air with a high nitrogen gas concentration from the tuyeres. Therefore, there was no knowledge about the reactivity of coke suitable for reducing the reducing agent ratio for blast furnaces that blow oxygen-containing gas with a concentration close to 100% as the blowing gas from the tuyeres and blow hydrocarbon-based reducing materials containing a lot of hydrogen other than pulverized coal from the tuyeres.
- the object of the present invention is to solve the above problems and propose a method of operating a blast furnace that can reduce the reducing agent ratio by using coke with appropriate reactivity in a so-called oxygen blast furnace, which blows oxygen-containing gas with a concentration of 80 vol.% or more from the tuyere as the blast gas.
- the blast furnace operation method of the present invention was developed to solve the above-mentioned problems, and is a method of operating a blast furnace in which iron-based raw materials and coke are charged in layers from the top of the blast furnace, and an oxygen-containing gas and a reducing agent containing a hydrocarbon gas are injected into the inside of the blast furnace from the tuyere of the blast furnace, characterized in that when the oxygen concentration of the oxygen-containing gas is 80 vol% or more, the coke has a reactivity index CRI of 35 or less.
- the hydrocarbon gas is a gas of hydrogen and/or a compound containing hydrogen; This is believed to be a more preferable solution.
- the blast furnace operation method of the present invention when oxygen-containing gas with a concentration of 80 vol.% or more is blown from the tuyere as the blast gas, it is possible to realize blast furnace operation with a reduced reducing agent ratio by using coke with an appropriate reactivity having a reactivity index CRI of 35 or less.
- 1 is a graph showing the relationship between CRI and reducing agent ratio in a blast furnace according to the present invention. 1 is a graph showing the relationship between CRI and consumed C for the amount of smelting reduction and the amount of coke gasified in a blast furnace according to the present invention.
- iron-based raw materials and coke are charged in layers from the top of the blast furnace, an oxygen-containing gas with a concentration of 80 vol.% or more is blown from the tuyere of the blast furnace as a blast gas, and a reducing agent containing a hydrocarbon gas is blown in from the tuyere.
- the blast furnace operating method of the present invention uses oxygen-containing gas as the blast gas, rather than hot air.
- hot air air heated to about 1200°C
- the flame temperature in the raceway is unlikely to reach a high temperature because the combustion gas contains about 50 vol% nitrogen, which does not contribute to the combustion reaction. Therefore, when a reducing material containing a large amount of hydrocarbon gas is blown into the blast furnace, the tuyere temperature drops and operational problems occur.
- the blast furnace operation method of the present invention by using an oxygen-containing gas as the blast gas, it is possible to suppress the inclusion of nitrogen gas that does not contribute to the combustion reaction, and it is therefore possible to raise the tuyere tip temperature to a sufficient level.
- the temperature of the flame in the raceway can be made higher than when hot air is used.
- the oxygen concentration in the oxygen-containing gas is 80 vol% or more. If the oxygen concentration in the oxygen-containing gas is low, a sufficient tuyere temperature cannot be ensured when a large amount of hydrocarbon gas is blown in, and there is a risk of operational trouble. Therefore, the oxygen concentration in the oxygen-containing gas needs to be 80 vol% or more, preferably 90 vol% or more, and more preferably 95 vol% or more. The oxygen concentration may be 100 vol%.
- the remaining gas other than oxygen in the oxygen-containing gas may contain, for example, nitrogen, carbon dioxide, argon, water vapor, etc.
- the concentration in the oxygen-containing gas is preferably low, and the concentration of water vapor per 1 Nm3 of oxygen-containing gas is preferably 10 g/ Nm3 or less, more preferably 5 g/ Nm3 or less.
- the hydrocarbon gas is preferably a gas containing hydrogen and/or a compound containing hydrogen.
- it may be methane, ethane, propane, ethylene, propylene, methanol, ethanol, etc.
- It may also be a gas that contains at least a portion of these gases, such as natural gas, city gas, coke oven gas, etc., supplied from an external source.
- It may also be a regenerated gas produced using blast furnace gas.
- it may be a regenerated methane gas obtained by reacting carbon monoxide and/or carbon dioxide contained in blast furnace gas with hydrogen by the method described in Patent Document 5.
- reducing agents such as pulverized coal, waste plastics, and reducing gases such as carbon monoxide gas may be used together with the hydrocarbon gas.
- the amount of the other reducing agents injected into the blast furnace is preferably 20 wt% or less of the total amount of reducing agents injected including the hydrocarbon gas.
- the unit "kg/t" is the amount of other reducing agents injected into the blast furnace when producing 1 ton of molten iron.
- they may be introduced into the hydrocarbon gas supply section together.
- pulverized coal or waste plastics it is preferable to provide a separate reducing agent supply section (path) for circulating the pulverized coal or waste plastics, separate from the hydrocarbon gas supply section.
- Non-Patent Document 2 The inventors used a two-dimensional blast furnace numerical model considering reactions, heat transfer, and material flow as shown in Non-Patent Document 2 to investigate the change in reducing agent ratio when operating a blast furnace using coke with different reactivity so that the molten iron temperature and iron production rate were constant.
- CRI Coke Reaction Index
- CRI Carbon Reaction Index
- Methane was used as the hydrocarbon reducing agent, and a study was conducted with a methane ratio of 148 kg/t.
- the reactivity of the coke is preferably as low as possible from the viewpoint of reducing the reducing agent ratio, and furthermore, in order to keep the reducing agent ratio in blast furnace operation below a specified amount, the CRI is required to be below a certain level.
- the blast furnace was operated by varying the CRI of the coke used under the operating parameters shown in Table 1 below, namely, pulverized coal ratio (0 kg/t), methane ratio (148 kg/t), oxygen-containing gas consumption rate (316-318 Nm3 /t), oxygen concentration in the oxygen-containing gas (100%), oxygen-containing gas temperature (25°C), and oxygen-containing gas moisture (0 g/ Nm3 ).
- the operating parameters were set based on the results shown in Figure 1.
- the coke rate was adjusted (331-342 kg/t) to obtain a pig iron production rate (2.2 t/day/ m3 ) and a molten iron temperature (1510°C).
- Table 1 shows the results of operation of a blast furnace in which the oxygen concentration of the blast air from the tuyere is 100 vol% and methane, a hydrocarbon gas, is blown in from the tuyere.
- the reducing agent ratio coke ratio + pulverized coal ratio + methane ratio.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Iron (AREA)
Abstract
Proposed is a blast furnace operation method through which the reduction material ratio can be decreased by using coke having suitable reactivity. The blast furnace operation method includes charging an iron-based raw material and coke through the top of a blast furnace in a layered manner, and blowing an oxygen-containing gas and a reduction material containing a hydrocarbon-based gas into the blast furnace through the tuyere of the blast furnace. When the oxygen concentration of the oxygen-containing gas is 80 vol% or higher, operation is performed using coke having a chemical reactivity index CRI of 35 or lower. The hydrocarbon-based gas is preferably hydrogen and/or a compound including hydrogen.
Description
本発明は、高炉操業において還元材比を低減できる高炉の操業方法に関する。
The present invention relates to a method for operating a blast furnace that can reduce the reducing agent ratio during blast furnace operation.
一般に、高炉では、炉頂から鉄系原料とコークスとを層状に装入し、炉下部の羽口から熱風（高温の空気）と、微粉炭を始めとする還元補助剤を吹き込む操業を行う。これにより、炉内を降下する鉄系原料を炉下部から上昇する還元ガスで還元することで、銑鉄を製造する。
Generally, in a blast furnace, iron-based raw materials and coke are charged in layers from the top of the furnace, and hot air (high-temperature air) and reducing agents such as pulverized coal are blown in from tuyeres at the bottom of the furnace. In this way, pig iron is produced by reducing the iron-based raw materials descending inside the furnace with the reducing gas rising from the bottom of the furnace.
上記のように、高炉操業においては、炉内の鉄源を還元するためにコークスや微粉炭等の還元材が使用される。銑鉄１トンを製造するのに要した還元材の重量合計は還元材比と呼ばれる。還元材比を減らすことができれば、高炉からのＣＯ２排出量や銑鉄の製造コストを削減できるため、還元材比の低減は高炉操業の重要な課題であり、数多くの技術開発が行われてきた。
As described above, in blast furnace operation, reducing agents such as coke and pulverized coal are used to reduce the iron source in the furnace. The total weight of reducing agents required to produce one ton of pig iron is called the reducing agent ratio. If the reducing agent ratio can be reduced, CO2 emissions from the blast furnace and the production costs of pig iron can be reduced. Therefore, reducing the reducing agent ratio is an important issue in blast furnace operation, and many technical developments have been carried out.
例えば、特許文献１や特許文献２に開示されているように、高反応性コークスを使用して還元材比を低減する技術がある。コークスの反応性が高いと、Ｃ＋ＣＯ２＝２ＣＯで表されるコークスのガス化反応が低温から開始する。ガス化反応は大きな吸熱反応であるから、ガス化反応が低温から開始すると、高炉内の熱保存帯温度が低下する。これにより、ＦｅＯ－Ｆｅの還元平衡点が還元ガス濃度の低い側へ移動する。その結果、炉内還元ガス濃度と還元平衡点還元ガス濃度との差が拡大して間接還元が促進されることで、溶融還元（反応式：ＦｅＯ＋Ｃ＝Ｆｅ＋ＣＯ）量が減少するため、還元材比が減少する。
For example, as disclosed in Patent Document 1 and Patent Document 2, there is a technique for reducing the reducing agent ratio by using highly reactive coke. When the reactivity of the coke is high, the gasification reaction of the coke, which is expressed by C+CO 2 =2CO, starts at a low temperature. Since the gasification reaction is a large endothermic reaction, when the gasification reaction starts at a low temperature, the thermal reserve zone temperature in the blast furnace decreases. This causes the reduction equilibrium point of FeO-Fe to move to the side with a lower reducing gas concentration. As a result, the difference between the reducing gas concentration in the furnace and the reducing gas concentration at the reduction equilibrium point increases, promoting indirect reduction, and thus reducing the amount of smelting reduction (reaction formula: FeO+C=Fe+CO), and thus reducing the reducing agent ratio.
高反応性コークスの代表として、フェロコークスがよく知られている。フェロコークスは、石炭に鉄鉱石粉を混ぜて乾留し製造したコークスであり、コークス中に内包されたＦｅがコークスのガス化反応の触媒となることで反応性を高める。特許文献３、特許文献４および非特許文献１には、フェロコークスを使用することで還元材比を低減できる旨が記載されている。
Ferro coke is well known as a representative example of highly reactive coke. Ferro coke is produced by mixing coal with iron ore powder and carbonizing it, and the Fe contained within the coke acts as a catalyst for the gasification reaction of the coke, increasing its reactivity. Patent Document 3, Patent Document 4, and Non-Patent Document 1 state that the reducing agent ratio can be reduced by using ferro coke.
ところで、近年、カーボンニュートラル社会の実現に向け、鉄鋼業界全体でＣＯ２排出量を大幅に削減する技術の開発が進められている。ＣＯ２を大量に排出する高炉も例外ではなく、例えば、特許文献５に示されるような、羽口から送風ガスとして濃度が１００％に近い酸素含有ガスを送風し、還元材としてメタンを吹き込む形態の高炉が検討されている。この高炉は、羽口から熱風ではなく高濃度酸素含有ガスを送風し、かつ、羽口から還元材として微粉炭ではなくメタンを大量に吹き込む点が従来の一般的な高炉とは異なっており、操業条件が大きく変化している。
In recent years, the steel industry as a whole has been developing technologies to significantly reduce CO2 emissions in order to realize a carbon-neutral society. Blast furnaces, which emit large amounts of CO2 , are no exception. For example, as shown in Patent Document 5, a blast furnace in which an oxygen-containing gas with a concentration close to 100% is blown from the tuyere as a blast gas and methane is blown in as a reducing agent is being considered. This blast furnace is different from conventional general blast furnaces in that a high-concentration oxygen-containing gas is blown from the tuyere instead of hot air, and a large amount of methane is blown in instead of pulverized coal as a reducing agent from the tuyere, and the operating conditions have changed significantly.
フェロコークスに代表される高反応性コークスを使用して還元材比を低減させる高炉の操業方法は、羽口から熱風と微粉炭を主とする還元材を吹き込む従来の一般的な高炉に対して有効であることが知られている。しかし一方で、特許文献５に示されるような、羽口から送風ガスとして濃度が１００％に近い酸素含有ガスを送風し、かつ、羽口から微粉炭以外の水素を多く含む炭化水素系還元材を吹き込む高炉に対しては、詳細な検討が行われていない。そのため、そのような高炉において高反応性コークスを使用した場合に、従来の一般的な高炉と同様の還元材比低減効果が得られるかは明らかではなく、また還元材比低減に適したコークスの反応性についても明らかではない。
It is known that the method of operating a blast furnace to reduce the reducing agent ratio by using a highly reactive coke such as ferrocoke is effective for conventional general blast furnaces in which hot air and reducing agents mainly consisting of pulverized coal are blown in from the tuyere. However, no detailed study has been conducted on blast furnaces in which an oxygen-containing gas with a concentration close to 100% is blown in from the tuyere as the blast gas, and a hydrogen-rich hydrocarbon-based reducing agent other than pulverized coal is blown in from the tuyere, as shown in Patent Document 5. Therefore, it is not clear whether the use of highly reactive coke in such a blast furnace will achieve the same reducing agent ratio reduction effect as that of a conventional general blast furnace, and the reactivity of the coke suitable for reducing the reducing agent ratio is also not clear.
この点で、例えば特許文献６では、水素ガスを含む水素含有ガスを大量に高炉に吹き込む際には、コークスのガス化反応による吸熱を抑制させるためにコークスの反応性を低下させることが有効であると開示されている。しかしながら、特許文献６が対象としているのは羽口から窒素ガス濃度の高い熱風を送風する高炉である。そのため、羽口から送風ガスとして濃度が１００％に近い酸素含有ガスを送風し、かつ、羽口から微粉炭以外の水素を多く含む炭化水素系還元材を吹き込む高炉に対しては、還元材比低減に適したコークスの反応性についての知見がなかった。
In this regard, for example, Patent Document 6 discloses that when injecting a large amount of hydrogen-containing gas, including hydrogen gas, into a blast furnace, it is effective to reduce the reactivity of the coke in order to suppress the endothermic heat caused by the gasification reaction of the coke. However, Patent Document 6 targets blast furnaces that blow hot air with a high nitrogen gas concentration from the tuyeres. Therefore, there was no knowledge about the reactivity of coke suitable for reducing the reducing agent ratio for blast furnaces that blow oxygen-containing gas with a concentration close to 100% as the blowing gas from the tuyeres and blow hydrocarbon-based reducing materials containing a lot of hydrogen other than pulverized coal from the tuyeres.
本発明の目的は、上記の問題点を解決し、羽口から送風ガスとして濃度が８０ｖｏｌ％以上の酸素含有ガスを送風するいわゆる酸素高炉において、適切な反応性のコークスを使用することにより、還元材比を低減することができる高炉の操業方法を提案することにある。
The object of the present invention is to solve the above problems and propose a method of operating a blast furnace that can reduce the reducing agent ratio by using coke with appropriate reactivity in a so-called oxygen blast furnace, which blows oxygen-containing gas with a concentration of 80 vol.% or more from the tuyere as the blast gas.
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、高炉の炉頂から、鉄系原料およびコークスを層状に装入し、高炉の羽口から、酸素含有ガスと炭化水素系ガスを含む還元材とを前記高炉の内部に吹込む高炉の操業方法であって、前記酸素含有ガスの酸素濃度が８０ｖｏｌ％以上であった場合、前記コークスとして反応性指数ＣＲＩが３５以下のコークスを用いて操業することを特徴とする、高炉の操業方法である。
The blast furnace operation method of the present invention was developed to solve the above-mentioned problems, and is a method of operating a blast furnace in which iron-based raw materials and coke are charged in layers from the top of the blast furnace, and an oxygen-containing gas and a reducing agent containing a hydrocarbon gas are injected into the inside of the blast furnace from the tuyere of the blast furnace, characterized in that when the oxygen concentration of the oxygen-containing gas is 80 vol% or more, the coke has a reactivity index CRI of 35 or less.
なお、前記のように構成される本発明に係る高炉の操業方法においては、
（１）前記炭化水素系ガスは、水素および／または水素を含む化合物のガスであること、
がより好ましい解決手段となるものと考えられる。 In the method for operating a blast furnace according to the present invention configured as described above,
(1) The hydrocarbon gas is a gas of hydrogen and/or a compound containing hydrogen;
This is believed to be a more preferable solution.
（１）前記炭化水素系ガスは、水素および／または水素を含む化合物のガスであること、
がより好ましい解決手段となるものと考えられる。 In the method for operating a blast furnace according to the present invention configured as described above,
(1) The hydrocarbon gas is a gas of hydrogen and/or a compound containing hydrogen;
This is believed to be a more preferable solution.
本発明の高炉の操業方法によれば、羽口から送風ガスとして濃度が８０ｖｏｌ％以上の酸素含有ガスを送風する場合、反応性指数ＣＲＩが３５以下の適切な反応性のコークスを使用することで、還元材比を低減させる高炉操業を実現することができる。
According to the blast furnace operation method of the present invention, when oxygen-containing gas with a concentration of 80 vol.% or more is blown from the tuyere as the blast gas, it is possible to realize blast furnace operation with a reduced reducing agent ratio by using coke with an appropriate reactivity having a reactivity index CRI of 35 or less.
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。
Below, the embodiments of the present invention are specifically described. Note that the following embodiments are intended to exemplify devices and methods for embodying the technical ideas of the present invention, and are not intended to specify the configurations as described below. In other words, the technical ideas of the present invention can be modified in various ways within the technical scope described in the claims.
まず、本実施形態に係る高炉の操業方法について説明する。本実施形態に係る高炉の操業方法では、高炉の炉頂から、鉄系原料およびコークスを層状に装入し、高炉の羽口から送風ガスとして濃度が８０ｖｏｌ％以上の酸素含有ガスを送風し、羽口から炭化水素系ガスを含む還元材を吹き込む。
First, the method of operating a blast furnace according to this embodiment will be described. In the method of operating a blast furnace according to this embodiment, iron-based raw materials and coke are charged in layers from the top of the blast furnace, an oxygen-containing gas with a concentration of 80 vol.% or more is blown from the tuyere of the blast furnace as a blast gas, and a reducing agent containing a hydrocarbon gas is blown in from the tuyere.
ここで、本発明の高炉の操業方法は、熱風ではなく、酸素含有ガスを送風ガスとして用いる。送風ガスとして、熱風（１２００℃程度に加熱した空気）を使用する場合、燃焼ガス中に燃焼反応に寄与しない５０ｖｏｌ％程度の窒素が含まれるため、レースウェイにおける火炎の温度は高温となり難い。そのため、高炉内に多量の炭化水素系ガスを含む還元材を吹き込むと、羽口先温度が低下し操業トラブルが生じる。
Here, the blast furnace operating method of the present invention uses oxygen-containing gas as the blast gas, rather than hot air. When hot air (air heated to about 1200°C) is used as the blast gas, the flame temperature in the raceway is unlikely to reach a high temperature because the combustion gas contains about 50 vol% nitrogen, which does not contribute to the combustion reaction. Therefore, when a reducing material containing a large amount of hydrocarbon gas is blown into the blast furnace, the tuyere temperature drops and operational problems occur.
一方、本発明の高炉の操業方法では、送風ガスとして酸素含有ガスを使用することにより、燃焼反応に寄与しない窒素ガスの混入を抑制できるので、羽口先温度を十分な温度まで昇温することが可能となる。すなわち、レースウェイにおける火炎の温度を、熱風を使用する場合と比べて高温とすることができる。
On the other hand, in the blast furnace operation method of the present invention, by using an oxygen-containing gas as the blast gas, it is possible to suppress the inclusion of nitrogen gas that does not contribute to the combustion reaction, and it is therefore possible to raise the tuyere tip temperature to a sufficient level. In other words, the temperature of the flame in the raceway can be made higher than when hot air is used.
酸素含有ガスにおける酸素濃度は、８０ｖｏｌ％以上とする。酸素含有ガスにおける酸素濃度が低いと、多量の炭化水素系ガスを吹き込む場合に十分な羽口先温度を確保できず、操業トラブルが生じる恐れがある。そのため、酸素含有ガスにおける酸素濃度は８０ｖｏｌ％以上が必要で、好ましくは９０ｖｏｌ％以上、さらに好ましくは９５ｖｏｌ％以上である。酸素濃度は１００ｖｏｌ％であってもよい。なお、酸素含有ガス中の酸素以外の残部ガスとしては、例えば、窒素や二酸化炭素、アルゴン、水蒸気等が含まれていてもよい。水蒸気は羽口先温度を低下させるため、酸素含有ガス中の濃度は低い方がよく、酸素含有ガス１Ｎｍ３当たりの水蒸気の濃度は、好ましくは１０ｇ／Ｎｍ３以下、さらに好ましくは５ｇ／Ｎｍ３以下とするのが好ましい。
The oxygen concentration in the oxygen-containing gas is 80 vol% or more. If the oxygen concentration in the oxygen-containing gas is low, a sufficient tuyere temperature cannot be ensured when a large amount of hydrocarbon gas is blown in, and there is a risk of operational trouble. Therefore, the oxygen concentration in the oxygen-containing gas needs to be 80 vol% or more, preferably 90 vol% or more, and more preferably 95 vol% or more. The oxygen concentration may be 100 vol%. In addition, the remaining gas other than oxygen in the oxygen-containing gas may contain, for example, nitrogen, carbon dioxide, argon, water vapor, etc. Since water vapor lowers the tuyere temperature, the concentration in the oxygen-containing gas is preferably low, and the concentration of water vapor per 1 Nm3 of oxygen-containing gas is preferably 10 g/ Nm3 or less, more preferably 5 g/ Nm3 or less.
炭化水素系ガスは、水素および／または水素を含む化合物を含むガスであることが好ましい。例えば、メタン、エタン、プロパン、エチレン、プロピレン、メタノール、エタノール等であってよい。また、これらのガスを一部でも含み構成されるガス、例えば外部から供給される天然ガス、都市ガス、コークス炉ガス等であってよい。さらに、高炉ガスを利用して生成された再生ガスであってよい。例えば、特許文献５に記載の方法により、高炉ガスに含まれる一酸化炭素および／または二酸化炭素と水素とを反応させて得た再生メタンガスであってよい。再生ガスを炭化水素系ガスとして利用することで、ＣＯ２の排出量を大幅に減少させることができる。
The hydrocarbon gas is preferably a gas containing hydrogen and/or a compound containing hydrogen. For example, it may be methane, ethane, propane, ethylene, propylene, methanol, ethanol, etc. It may also be a gas that contains at least a portion of these gases, such as natural gas, city gas, coke oven gas, etc., supplied from an external source. It may also be a regenerated gas produced using blast furnace gas. For example, it may be a regenerated methane gas obtained by reacting carbon monoxide and/or carbon dioxide contained in blast furnace gas with hydrogen by the method described in Patent Document 5. By using the regenerated gas as a hydrocarbon gas, it is possible to significantly reduce CO 2 emissions.
また、その他の吹込み還元材、例えば、微粉炭や廃プラスチック、一酸化炭素ガス等の還元ガスを、炭化水素系ガスと一緒に使用してもよい。なお、その他の吹込み還元材の高炉内への吹込み量は、炭化水素系ガスを含む吹込み還元材の合計量に対して２０ｗｔ％以下とすることが好ましい。ここで、「ｋｇ／ｔ」という単位は、溶銑１ｔを製造する際に高炉内へ吹込むその他の吹込み還元材の量である。その他の吹込み還元材を使用する場合、炭化水素系ガス供給部に、その他の吹込み還元材も一緒に導入してもよい。また、その他の吹込み還元材として、微粉炭や廃プラスチックを用いる場合には、炭化水素系ガス供給部とは別に、微粉炭や廃プラスチックを流通させる別の還元材供給部（路）を設けることが好ましい。
Furthermore, other reducing agents such as pulverized coal, waste plastics, and reducing gases such as carbon monoxide gas may be used together with the hydrocarbon gas. The amount of the other reducing agents injected into the blast furnace is preferably 20 wt% or less of the total amount of reducing agents injected including the hydrocarbon gas. Here, the unit "kg/t" is the amount of other reducing agents injected into the blast furnace when producing 1 ton of molten iron. When other reducing agents are used, they may be introduced into the hydrocarbon gas supply section together. When pulverized coal or waste plastics are used as the other reducing agents, it is preferable to provide a separate reducing agent supply section (path) for circulating the pulverized coal or waste plastics, separate from the hydrocarbon gas supply section.
発明者らは、非特許文献２に示される反応、伝熱、物質流れを考慮した２次元高炉数値モデルを用いて、反応性の異なるコークスを使用し、溶銑温度、出銑量が一定となるように高炉を操業した際の還元材比の変化を調査した。
The inventors used a two-dimensional blast furnace numerical model considering reactions, heat transfer, and material flow as shown in Non-Patent Document 2 to investigate the change in reducing agent ratio when operating a blast furnace using coke with different reactivity so that the molten iron temperature and iron production rate were constant.
コークスの反応性には、実際の操業管理指標としても用いられているＣＲＩ（Ｃｏｋｅ Ｒｅａｃｔｉｏｎ Ｉｎｄｅｘ）を採用し、検討を行った。ＣＲＩは以下のようにして求める。すなわち、２０±１ｍｍの大きさ（粒度）に調整されたコークス２００ｇを、ガス組成：ＣＯ２（１００ｍｏｌ％）、反応温度１１００℃ 、反応時間２時間の条件で反応させる。ついで、反応後試料の質量を測定し、（反応前質量－反応後質量）／反応前質量×１００を求める。これをＣＲＩとする。
For the reactivity of coke, CRI (Coke Reaction Index), which is also used as an actual operational management index, was adopted and examined. CRI is calculated as follows. That is, 200 g of coke adjusted to a size (particle size) of 20±1 mm is reacted under the conditions of gas composition: CO 2 (100 mol%), reaction temperature of 1100° C., and reaction time of 2 hours. Next, the mass of the sample after the reaction is measured to calculate (mass before reaction−mass after reaction)/mass before reaction×100. This is defined as CRI.
炭化水素系還元材にはメタンを採用し、メタン比１４８ｋｇ／ｔでの検討を行った。
Methane was used as the hydrocarbon reducing agent, and a study was conducted with a methane ratio of 148 kg/t.
上記高炉数値モデルの計算結果によると、羽口から、羽口から送風ガスとして濃度が１００ｖｏｌ％の酸素含有ガスを送風し、メタンを吹き込む高炉では、ＣＲＩが低いほど還元材比が減少した（図１参照）。したがって、従来の一般的な高炉で好ましいとされていた高反応性コークスは、本発明に係る高炉では還元材比低減に不利である。逆に、還元材比低減には低反応性コークスが有利である。ここで、図１に示すグラフにおいて、還元材比４８５ｋｇ／ｔ以下のグラフの傾きは、還元材比４８７ｋｇ／ｔ以上のグラフの傾きより、急峻となっている。そこで、本発明では、還元材比が４８５ｋｇ／ｔ以下を目標とした。
According to the calculation results of the blast furnace numerical model, in a blast furnace in which an oxygen-containing gas with a concentration of 100 vol% is blown from the tuyere as the blast gas and methane is blown in, the lower the CRI, the lower the reducing agent ratio (see Figure 1). Therefore, high reactivity coke, which was considered preferable in conventional blast furnaces, is disadvantageous for reducing the reducing agent ratio in the blast furnace of the present invention. Conversely, low reactivity coke is advantageous for reducing the reducing agent ratio. Here, in the graph shown in Figure 1, the slope of the graph for reducing agent ratios of 485 kg/t or less is steeper than the slope of the graph for reducing agent ratios of 487 kg/t or more. Therefore, in the present invention, a reducing agent ratio of 485 kg/t or less is targeted.
これは、次のような理由によるものである。羽口から送風ガスとして濃度が１００ｖｏｌ％の酸素含有ガスを送風し、水素を多く含む炭化水素系還元材を大量に吹き込むことにより炉内の水素濃度が上昇する。さらに、送風の窒素レス化により還元ガス濃度が相対的に高くなる。これにより、還元効率が向上し溶融還元量が減少するため、コークスの反応性が下がると、溶融還元量の増加以上にコークスガス化量が減少し、還元材比が減少する（図２参照）。溶融還元とコークスガス化はともに大きな吸熱反応であり、還元材比を増加させる要因である。
This is due to the following reasons. By blowing in a large amount of hydrogen-rich hydrocarbon reducing agent and blowing in an oxygen-containing gas with a concentration of 100 vol.% from the tuyere as the blast gas, the hydrogen concentration in the furnace increases. Furthermore, the nitrogen-free blast gas makes the reducing gas concentration relatively high. As a result, the reduction efficiency improves and the amount of smelting reduction decreases, so if the reactivity of the coke decreases, the amount of coke gasification decreases more than the increase in the amount of smelting reduction, and the reducing agent ratio decreases (see Figure 2). Both smelting reduction and coke gasification are large endothermic reactions, and are factors that increase the reducing agent ratio.
以上より、羽口から送風ガスとして濃度が８０ｖｏｌ％以上の酸素含有ガスを送風し、羽口から炭化水素系ガスを含む還元材を吹き込む高炉においては、還元材比低減の観点からコークスの反応性はなるべく低い方が良く、さらに高炉操業における還元材比を所定量以下とするため、ＣＲＩが一定以下であることが要求される。
From the above, in a blast furnace where oxygen-containing gas with a concentration of 80 vol.% or more is blown from the tuyere as the blast gas and a reducing agent containing a hydrocarbon gas is blown from the tuyere, the reactivity of the coke is preferably as low as possible from the viewpoint of reducing the reducing agent ratio, and furthermore, in order to keep the reducing agent ratio in blast furnace operation below a specified amount, the CRI is required to be below a certain level.
以下の表１に示す、微粉炭比（０ｋｇ／ｔ）、メタン比（１４８ｋｇ／ｔ）、酸素含有ガス原単位（３１６～３１８Ｎｍ３／ｔ）、酸素含有ガス中の酸素濃度（１００％）、酸素含有ガス温度（２５℃）、酸素含有ガス湿分（０ｇ／Ｎｍ３）の操業諸元のもとで、用いるコークスのＣＲＩを変化させて、高炉の操業を行った。なお、上記の操業諸元は図１の結果に基づいて設定した。出銑比（２．２ｔ／ｄａｙ／ｍ３）および溶銑温度（１５１０℃）が得られるよう、コークス比を調整した（３３１～３４２ｋｇ／ｔ）。
The blast furnace was operated by varying the CRI of the coke used under the operating parameters shown in Table 1 below, namely, pulverized coal ratio (0 kg/t), methane ratio (148 kg/t), oxygen-containing gas consumption rate (316-318 Nm3 /t), oxygen concentration in the oxygen-containing gas (100%), oxygen-containing gas temperature (25°C), and oxygen-containing gas moisture (0 g/ Nm3 ). The operating parameters were set based on the results shown in Figure 1. The coke rate was adjusted (331-342 kg/t) to obtain a pig iron production rate (2.2 t/day/ m3 ) and a molten iron temperature (1510°C).
表１の結果から以下のことが分かった。まず、羽口からの送風の酸素濃度が１００ｖｏｌ％であり、羽口から炭化水素系ガスであるメタンを吹き込む高炉の操業結果である表１において、還元材比（コークス比＋微粉炭比＋メタン比）に着目した。その結果、表１の各例において、目標とする還元材比４８５ｋｇ／ｔ以下を、発明例１－１（還元材比４７９ｋｇ／ｔ）、発明例１－２（還元材比４８１ｋｇ／ｔ）、発明例１－３（還元材比４８３ｋｇ／ｔ）が満たしていることがわかった。一方、比較例１－１（還元材比４８７ｋｇ／ｔ）、比較例１－２（還元材比４８９ｋｇ／ｔ）、比較例１－３（還元材比４９０ｋｇ／ｔ）は、目標とする還元材比４８５ｋｇ／ｔ以下を満たしていないことがわかった。図１および上記結果から、本発明では、ＣＲＩを３５以下とする必要があることがわかった。
The results in Table 1 reveal the following. First, in Table 1, which shows the results of operation of a blast furnace in which the oxygen concentration of the blast air from the tuyere is 100 vol% and methane, a hydrocarbon gas, is blown in from the tuyere, attention was focused on the reducing agent ratio (coke ratio + pulverized coal ratio + methane ratio). As a result, it was found that in each example in Table 1, invention example 1-1 (reducing agent ratio 479 kg/t), invention example 1-2 (reducing agent ratio 481 kg/t), and invention example 1-3 (reducing agent ratio 483 kg/t) meet the target reducing agent ratio of 485 kg/t or less. On the other hand, it was found that comparative example 1-1 (reducing agent ratio 487 kg/t), comparative example 1-2 (reducing agent ratio 489 kg/t), and comparative example 1-3 (reducing agent ratio 490 kg/t) do not meet the target reducing agent ratio of 485 kg/t or less. From FIG. 1 and the above results, it was found that in the present invention, the CRI needs to be 35 or less.
Claims (2)
- 高炉の炉頂から、鉄系原料およびコークスを層状に装入し、高炉の羽口から、酸素含有ガスと炭化水素系ガスを含む還元材とを前記高炉の内部に吹込む高炉の操業方法であって、前記酸素含有ガスの酸素濃度が８０ｖｏｌ％以上であった場合、前記コークスとして反応性指数ＣＲＩが３５以下のコークスを用いて操業することを特徴とする、高炉の操業方法。 A method of operating a blast furnace in which iron-based raw materials and coke are charged in layers from the top of the blast furnace, and an oxygen-containing gas and a reducing agent containing a hydrocarbon gas are blown into the interior of the blast furnace from the tuyere of the blast furnace, characterized in that when the oxygen concentration of the oxygen-containing gas is 80 vol% or more, the coke has a reactivity index CRI of 35 or less.
- 前記炭化水素系ガスは、水素および／または水素を含む化合物のガスであることを特徴とする、請求項１に記載の高炉の操業方法。 The method for operating a blast furnace according to claim 1, characterized in that the hydrocarbon gas is hydrogen and/or a gas of a compound containing hydrogen.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2023-020829 | 2023-02-14 | ||
| JP2023020829 | 2023-02-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2024171511A1 true WO2024171511A1 (en) | 2024-08-22 |
Family
ID=92421058
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2023/036755 WO2024171511A1 (en) | 2023-02-14 | 2023-10-10 | Blast furnace operation method |
Country Status (2)
| Country | Link |
|---|---|
| TW (1) | TW202432841A (en) |
| WO (1) | WO2024171511A1 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08188808A (en) * | 1995-01-06 | 1996-07-23 | Nippon Steel Corp | Method for operating blast furnace |
| JPH09170008A (en) * | 1995-12-19 | 1997-06-30 | Nippon Steel Corp | Operation method for blowing large amount of pulverized coat in blast furnace |
| WO2021106578A1 (en) * | 2019-11-25 | 2021-06-03 | Ｊｆｅスチール株式会社 | Blast furnace operation method and blast furnace ancillary equipment |
| JP2022149214A (en) * | 2021-03-25 | 2022-10-06 | 日本製鉄株式会社 | Blast furnace operation method |
-
2023
- 2023-10-10 WO PCT/JP2023/036755 patent/WO2024171511A1/en unknown
- 2023-12-28 TW TW112151231A patent/TW202432841A/en unknown
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08188808A (en) * | 1995-01-06 | 1996-07-23 | Nippon Steel Corp | Method for operating blast furnace |
| JPH09170008A (en) * | 1995-12-19 | 1997-06-30 | Nippon Steel Corp | Operation method for blowing large amount of pulverized coat in blast furnace |
| WO2021106578A1 (en) * | 2019-11-25 | 2021-06-03 | Ｊｆｅスチール株式会社 | Blast furnace operation method and blast furnace ancillary equipment |
| JP2022149214A (en) * | 2021-03-25 | 2022-10-06 | 日本製鉄株式会社 | Blast furnace operation method |
Also Published As
| Publication number | Publication date |
|---|---|
| TW202432841A (en) | 2024-08-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6986800B2 (en) | Method and apparatus for improved use of primary energy sources in integrated steel plants | |
| AU2011309835B2 (en) | Method and apparatus for producing direct reduced iron utilizing a source of reducing gas comprising hydrogen and carbon monoxide | |
| CA2715525C (en) | Method for the melting of pig iron with the recirculation of blast furnace gas and with the addition of hydrocarbons | |
| JP2009221547A (en) | Method for operating blast furnace | |
| KR102664149B1 (en) | Method for Operating a Blast Furnace | |
| CN108138058A (en) | The manufacturing method of the gasification process of carbonaceous fuel, the operating method of iron-smelter and gasifying gas | |
| WO2024171511A1 (en) | Blast furnace operation method | |
| SE438160B (en) | METHOD OF REDUCING METAL ORE | |
| LU500699B1 (en) | Method for operating a shaft furnace plant | |
| KR20240068674A (en) | Method for producing direct reduced iron for iron and steel plants | |
| WO2022243723A1 (en) | Operating method of a network of plants | |
| KR20230138002A (en) | Off-gas recovery from direct reduction process | |
| JP2020045508A (en) | Operation method of blast furnace | |
| US7238222B2 (en) | Thermal synthesis production of steel | |
| WO2024135695A1 (en) | Reduced iron production method | |
| US3620699A (en) | Reducing gas generation | |
| WO2024135696A1 (en) | Method for producing reduced iron | |
| WO2023162389A1 (en) | Method for reducing fine iron ore | |
| WO2024135698A1 (en) | Reduced iron manufacturing method | |
| RU2802414C1 (en) | Method of operation of blast furnace and auxiliary assembly of blast furnace | |
| WO2024135852A1 (en) | Reduced iron production method | |
| US20240240275A1 (en) | Method for manufacturing direct reduced iron and dri manufacturing equipment | |
| AU2022442457A1 (en) | Method of reducing iron ore powder | |
| Htet | Reaction mechanisms of natural gas in the HIsarna alternative ironmaking process | |
| CN115478122A (en) | Ammonia-rich raw fuel for blast furnace iron making and blast furnace iron making method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 23922845 Country of ref document: EP Kind code of ref document: A1 |