WO2026048209A1 - Procédé de production de fer réduit et four de réduction - Google Patents

Procédé de production de fer réduit et four de réduction

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Publication number
WO2026048209A1
WO2026048209A1 PCT/JP2025/020840 JP2025020840W WO2026048209A1 WO 2026048209 A1 WO2026048209 A1 WO 2026048209A1 JP 2025020840 W JP2025020840 W JP 2025020840W WO 2026048209 A1 WO2026048209 A1 WO 2026048209A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
carburizing
reduced iron
reducing
concentration
Prior art date
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Pending
Application number
PCT/JP2025/020840
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English (en)
Japanese (ja)
Inventor
晃太 盛家
光輝 照井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
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JFE Steel Corp
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Filing date
Publication date
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Publication of WO2026048209A1 publication Critical patent/WO2026048209A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes

Definitions

  • the present invention relates to a method for producing reduced iron and a reduction furnace.
  • iron oxide is reduced in a vertical reduction furnace (shaft furnace) to produce reduced iron.
  • agglomerated iron ore (hereinafter simply referred to as iron oxide) such as sintered ore or pellets is charged into the reduction furnace through an iron oxide charging port at the top of the reduction furnace as the iron oxide raw material.
  • a reducing gas containing CO and H2 is blown into the reduction furnace to reduce the iron oxide and produce reduced iron.
  • natural gas or the like is used as the raw material gas for the reducing gas. This raw material gas, together with the top gas, is heated and reformed in a reformer. This generates the reducing gas.
  • the top gas is the gas remaining after the reducing gas has been used to reduce the iron oxide in the reduction furnace and is generally discharged from the top of the reduction furnace.
  • the generated reducing gas is blown into the reduction furnace and reacts with the iron oxide supplied from above the reduction furnace.
  • the iron oxide is then reduced to produce reduced iron.
  • the reduced iron is then discharged from a reduced iron discharge port at the bottom of the reduction furnace.
  • Patent Document 1 discloses: "A method for producing reduced iron by reducing iron oxide, a reduced iron production step of reducing the iron oxide by bringing the iron oxide into contact with a reducing gas while causing it to drop from a top of a reduction furnace to produce reduced iron, and discharging the reduced iron from a bottom of the reduction furnace; a reformed gas generating step of extracting furnace top gas from the reducing furnace, adjusting the moisture content and removing dust from the gas to generate a process gas, and supplying at least the process gas into a reformer to generate a reformed gas containing carbon monoxide and hydrogen in the reformer; a reducing gas supplying step of supplying the generated reformed gas to the reducing furnace as the reducing gas; a cooling step of introducing a cooling gas into a cooling region set in a lower portion of the reducing furnace to cool the cooling region; and a reforming gas introducing step of extracting a portion of the reforming gas and
  • the reduced iron may be carburized in a region below the reducing gas injection position of the reducing furnace up to the reduced iron discharge port (hereinafter also referred to as the lower part of the reducing furnace; the region above the reducing gas injection position up to the iron oxide charging port is also referred to as the upper part of the reducing furnace) before being discharged from the reducing furnace.
  • carburization is a process of increasing the carbon content of the reduced iron by using a carburizing gas. Carburization is performed, for example, by injecting a gas mainly composed of CH4 or CO into the lower part of the reducing furnace and bringing the gas into contact with the reduced iron.
  • the carbon acts as an auxiliary heat source when melting the reduced iron. It also lowers the melting point of the reduced iron. As a result, the energy required to melt the reduced iron can be reduced.
  • HBI hot briquette iron
  • the carbon content of the reduced iron becomes excessively high, its formability into HBI decreases. Therefore, when carburizing in the lower part of the reduction furnace, it is necessary to control the carbon content of the reduced iron discharged from the furnace (hereinafter referred to as the final carbon content of the reduced iron) so that it falls within a target range.
  • Patent Document 1 With the technology of Patent Document 1, it is difficult to accurately control the final carbon content of the reduced iron, and improvements in this area are currently required.
  • the present invention was developed in light of the above-mentioned current situation, and aims to provide a method for producing reduced iron that enables accurate control of the final carbon content of the reduced iron. It also aims to provide a reduction furnace that can be suitably used in the above-mentioned method for producing reduced iron.
  • any numerical ranges expressed using "to” mean a range that includes the numerical values before and after "to” as the lower and upper limits, respectively.
  • the inventors have conducted extensive research to solve the above problems, and as a result have discovered that the above problems can be solved by changing the carburizing gas composition in accordance with the reducing gas composition, particularly the ratio of H2 /CO (hereinafter simply referred to as the H2 /CO of the reducing gas) which is the ratio of the H2 concentration to the CO concentration of the reducing gas.
  • the ratio of H2 /CO hereinafter simply referred to as the H2 /CO of the reducing gas
  • the present invention was completed based on the above findings and further investigation. Specifically, the gist of the present invention is as follows:
  • the method for producing reduced iron comprising:
  • the composition of the carburizing gas is changed so that the amount of carburization of the reduced iron in the carburizing step increases as the ratio of H2 /( H2 +CO), which is the ratio of the H2 concentration to the sum of the H2 concentration and the CO concentration of the reducing gas, deviates from 0.5; 2.
  • a reduction unit that reduces iron oxide with a reducing gas to produce reduced iron; a carburizing portion that increases the amount of carbon contained in the reduced iron by using a carburizing gas; a control unit that changes the composition of the carburizing gas in accordance with the composition of the reducing gas;
  • a reduction furnace having
  • the control unit the composition of the carburizing gas is changed so that the amount of carburization of the reduced iron in the carburized portion increases as the ratio of H2 /( H2 +CO), which is the ratio of the H2 concentration to the sum of the H2 concentration and CO concentration of the reducing gas, deviates from 0.5; 7.
  • control unit changes the CH4 concentration of the carburizing gas in accordance with H2 /( H2 +CO), which is the ratio of the H2 concentration to the sum of the H2 concentration and CO concentration of the reducing gas.
  • the reduced iron production method of the present invention allows for accurate control of the final carbon content of the reduced iron, which is extremely advantageous from an industrial perspective. Furthermore, the reduced iron production method of the present invention does not require large-scale expansion of facilities, making it extremely advantageous in terms of cost.
  • FIG. 1 is a schematic diagram illustrating an example of a schematic configuration of a reduction furnace and its auxiliary equipment.
  • FIG. 1 is a diagram showing an example of the relationship between the H 2 /(H 2 +CO) ratio of the reducing gas and the amount of carburization in the reduction step.
  • FIG. 1 is a schematic diagram illustrating an example of a schematic configuration of a reduction furnace having a control unit and its auxiliary equipment.
  • FIG. 2 is a schematic diagram illustrating an example of functional blocks of a control unit.
  • FIG. 1 is a schematic diagram showing an example of the general configuration of a reducing furnace and its auxiliary equipment used in a manufacturing method of reduced iron according to one embodiment of the present invention.
  • reference numeral 1 denotes a reducing furnace
  • 1a denotes iron oxide
  • 1b denotes reduced iron
  • 3 denotes a dust removal device
  • 4 denotes a dehydration device
  • 5 denotes a natural gas supply section
  • 6 denotes an air supply section
  • 7 denotes a reforming device
  • 8 denotes a reducing gas injection device
  • 9 denotes a carburizing gas injection device
  • 10 denotes a reduction section
  • 11 denotes a carburizing section.
  • iron oxide is charged into a reducing furnace through an iron oxide charging port and gradually lowered.
  • Reducing gas is then injected into the reducing furnace through a reducing gas inlet, and the iron oxide is reduced to produce reduced iron in the reduction section by the reducing gas.
  • Carburizing gas is also injected into the reducing furnace through a carburizing gas inlet at the bottom, and the carbon content of the reduced iron is increased by the carburizing gas in the carburizing section.
  • the reduced iron is then discharged from the reduced iron outlet of the reducing furnace.
  • a top gas containing mainly CO, CO 2 , H 2 , and H 2 O is discharged from the top of the reducing furnace.
  • This top gas is then cleaned in a dust removal device and its moisture content is adjusted in a dehydration device.
  • a portion of the top gas is then fed to a reformer as a first top gas, which serves as a raw material gas.
  • a CH 4 -containing gas, such as natural gas, is supplied to the reformer from a natural gas supply unit along with the first top gas.
  • the supplied gas is then heated in the reformer.
  • a reforming reaction then occurs, generating a high-temperature reducing gas containing mainly CO and H2 .
  • This reducing gas is then injected into the reducing furnace.
  • the remaining portion of the furnace top gas is used as a second furnace top gas, for example, as heating fuel in the combustion chamber of the reformer.
  • the second furnace top gas After being burned as heating fuel, the second furnace top gas is usually discharged outside the system, still containing CO2 .
  • the carburizing gas after being used for carburizing (hereinafter also referred to as "reacted carburizing gas”) is discharged outside the reducing furnace from a carburizing gas outlet located lower than the reducing gas inlet.
  • the reacted carburizing gas is, for example, cleaned using a dust removal device, and then a CH4 - containing gas, such as natural gas supplied from a natural gas supply unit, is added as needed, and the gas is again injected into the reducing furnace as carburizing gas.
  • Reduction step In the reduction step, a reducing gas is blown into the reduction furnace, and the iron oxide charged into the reduction furnace is reduced by the reducing gas blown into the reduction furnace to produce reduced iron.
  • the conditions for the reduction step are not particularly limited, and may be those of a conventional method.
  • the gas composition of the reducing gas is preferably CO: 1 to 70% by volume, H2 : 30 to 99% by volume, and the balance: 0 to 10% by volume.
  • the balance can be an inert gas such as N2 .
  • the reducing gas blowing temperature is preferably 800 to 1100°C, and the reducing gas blowing rate is preferably 1400 to 3000 Nm3 /t.
  • the iron oxide charging rate is preferably 1300 to 1500 kg/t.
  • carburizing process In the carburizing process, carburizing gas is injected into a reducing furnace to increase the carbon content of the reduced iron.
  • the composition of the carburizing gas may be determined by control in the control step described below.
  • the composition of the carburizing gas may be determined, for example, in the range of 30 to 100 volume % CH4 and the balance 0 to 70 volume %.
  • the balance may be an inert gas such as N2 .
  • the amount of carburizing gas injected may be constant or may be determined by control in the control step described below.
  • the amount of carburizing gas injected may be determined in the range of 50 Nm3 /t or more and 500 Nm3 /t or less.
  • Other conditions for the carburizing step are not particularly limited.
  • the carburizing gas injection temperature is preferably 0°C or more and 100°C or less.
  • Control process In the control process, it is important to change the composition of the carburizing gas depending on the composition of the reducing gas, particularly the H 2 /(H 2 +CO) of the reducing gas.
  • the amount of carburization in the reduction step increases according to the following formula (1).
  • H2 /( H2 +CO) becomes smaller than 0.5
  • black carbon powder is discharged from the reduced iron outlet of the reducing furnace along with the reduced iron.
  • the amount of carburization in the reduction process is less than the amount of carburization in the reduction process when the H2 /( H2 +CO) ratio of the reducing gas is 0.5.
  • the composition of the carburizing gas is changed depending on the composition of the reducing gas, particularly the H2 /( H2 +CO) ratio of the reducing gas.
  • the carburizing gas composition is changed so that the amount of carburization of reduced iron in the carburizing step (in other words, the amount of carburization of reduced iron in the carburizing section of the reducing furnace) increases as the H2 / ( H2 +CO) ratio of the reducing gas deviates from 0.5.
  • the carburizing gas composition is changed so that the amount of carburization in the carburizing step decreases as the H2/(H2+CO) ratio of the reducing gas deviates from 0.5.
  • the amount of carburization in the carburizing step can be controlled, for example, by changing the CH4 concentration in the carburizing gas to change the amount of CH4 supplied in the carburizing step. That is, CH4 has the effect of promoting carburization of reduced iron through the decomposition reaction of the following formula (3): Therefore, if the CH4 concentration of the carburizing gas is increased, the amount of carburization in the carburizing process increases, while if the CH4 concentration of the carburizing gas is decreased, the amount of carburization in the carburizing process decreases. CH 4 ⁇ C+2H 2 ...(3)
  • the amount of carburization in the carburizing process can also be controlled by changing the concentration of these gas species.
  • H2 affects the reaction equilibrium of the above formula (3), which in turn affects the amount of carburization in the carburizing process.
  • H2 concentration in the carburizing gas it is advantageous to reduce the H2 concentration in the carburizing gas.
  • H 2 O and CO 2 react with CH 4 according to the following formulas (4) and (5) to produce H 2 and CO.
  • CO and hydrocarbons having two or more carbon atoms generate C according to the following formulas (1), (2) and (6), which increases the amount of carburization in the carburization process.
  • n in the above formula (6) is an integer of 2 or more
  • m is an integer corresponding to the number n (the number of H atoms bonded to n C atoms).
  • X is more preferably equal to or greater than X0 + 100 ⁇
  • X is more preferably equal to or less than X0 + 110 ⁇
  • the right-hand side of the formula (7) exceeds X1 .
  • the left-hand side of the formula (7) exceeds X1 .
  • both the left-hand side (lower limit) and the right-hand side (upper limit) of the formula (7) are set to X1 .
  • the range of the formula (7) is set to X1 .
  • the inclusion of unavoidable impurities of less than 1% by volume is acceptable.
  • X1 is the upper limit CH4 concentration (volume %) of the carburizing gas and is determined by factors such as the amount of CH4 that can be supplied to the reducing furnace. For example, when a sufficient amount of CH4 can be supplied, X1 is 100. In this case, it is preferable to satisfy the following equation (8) in addition to the above equation (7).
  • X0 is the CH4 concentration (vol %) in the carburizing gas when the final carbon content of reduced iron targeted in actual operation (hereinafter also referred to as the target final carbon content of reduced iron) is obtained under conditions where the H2 / ( H2 +CO) ratio of the reducing gas is 0.5, particularly where the H2 concentration and CO concentration in the reducing gas are equal, and the remainder (remaining concentration: 10 vol % or less, preferably 5 vol % or less, more preferably 0 vol %) is an inert gas such as N2.
  • the conditions other than the composition of the reducing gas may be set based on the base operating conditions.
  • the base operating conditions are the amount of iron oxide charged, the composition of the reducing gas, the reducing gas blowing temperature, and the reducing gas blowing amount that are specified or recommended for the reducing furnace to be used in actual operation (hereinafter also referred to as the reducing furnace to be used).
  • the base operating conditions can be confirmed, for example, from the specifications (instruction manual) of the reducing furnace to be used or from past operating records. Conditions that cannot be confirmed from specifications, such as the composition of the iron oxide to be used and the carburizing gas blowing temperature and blowing amount, may be set according to the conditions planned for actual operation.
  • X0 can be determined by conducting a preliminary operation test of the reducing furnace to be used.
  • the reducing gas composition is 50% by volume H2 and 50% by volume CO, and other conditions are based on the base operating conditions of the reducing furnace to be used.
  • the preliminary operation test of the reducing furnace to be used is performed by varying the CH4 concentration of the carburizing gas. Conditions that cannot be confirmed in specifications, such as the composition of the iron oxide used and the injection temperature and injection amount of the carburizing gas, are set according to the conditions planned for actual operation. From the results of the preliminary operation test, the CH4 concentration of the carburizing gas when the target final carbon content of the reduced iron is obtained is determined and set as X0 .
  • X0 can take various values depending on the type (structure, size, etc.) of the reducing furnace to be used.
  • the remainder of the carburizing gas other than CH4 can be replaced with an inert gas such as N2 .
  • target final carbon content of the reduced iron is set, for example, in the range of 0.50 to 7.00 mass%.
  • the value of the left side of the above formula (7) exceeds X1 , it is preferable to change (increase) the injection amount of the carburizing gas in addition to the CH4 concentration of the carburizing gas. In this case, for example, it is preferable to change (increase) the injection amount of the carburizing gas so as to satisfy the following formula (8) while keeping the CH4 concentration of the carburizing gas at X1 .
  • V amount of carburizing gas blown in (Nm 3 /t)
  • V 0 Standard injection amount of carburizing gas (Nm 3 /t)
  • X CH4 concentration (vol %) of carburizing gas
  • X 0 Reference CH 4 concentration (vol %) of carburizing gas
  • X1 Upper limit of CH4 concentration (volume %) of carburizing gas
  • R H2 /( H2 +CO) of reducing gas.
  • V0 may be determined based on, for example, the amount of carburizing gas injected in the above-mentioned preliminary operation test (the amount of carburizing gas injected when the standard CH4 concentration of the carburizing gas is obtained) or the amount of carburizing gas injected under the operating conditions planned for actual operation.
  • X1 is determined based on the amount of CH4 that can be supplied to the reducing furnace. For example, if a sufficient amount of CH4 can be supplied, X1 will be 100.
  • the distribution step it is preferable to distribute the furnace gas into a first furnace gas and a second furnace gas.
  • the furnace gas is the gas obtained after the reducing gas has been used to reduce iron oxide in the reduction step.
  • the first furnace gas is supplied to a reformer and used as a raw material gas for the reducing gas in the reforming step.
  • the second furnace gas is used as heating fuel in the combustion chamber of the reformer.
  • a portion of the furnace gas may be distributed to a location other than the first furnace gas and the second furnace gas, for example, to be supplied to another device or stored. The distribution amount may be determined appropriately depending on the operating conditions.
  • the means for distributing and controlling the flow rate of the furnace gas is not particularly limited and can be conventional.
  • a mass flow controller can be used.
  • the reforming process it is preferable to generate a reducing gas from the first furnace gas and a CH4- containing gas.
  • the first furnace gas and natural gas which is a CH4- containing gas
  • the supplied gas is then heated in the reformer.
  • the reforming reactions of the following formulas (4)' and (5)' occur, generating a high-temperature reducing gas containing mainly CO and H2 .
  • CH 4 +CO 2 ⁇ 2CO+2H 2 ⁇ H 247kJ/mol...(4)'
  • CH4 + H2O ⁇ CO+ 3H2 ⁇ H 206kJ/mol...(5)'
  • a reduction furnace may include, for example: a reduction section that reduces iron oxide with a reducing gas to produce reduced iron; a carburizing portion that increases the amount of carbon contained in the reduced iron by using a carburizing gas; a control unit that changes the composition of the carburizing gas in accordance with the composition of the reducing gas;
  • 3 is a schematic diagram showing an example of the general configuration of a reduction furnace having a control unit and its auxiliary equipment.
  • reference numeral 12 denotes the control unit.
  • the configuration of the reduction section is not particularly limited, and a general one can be used.
  • the reduction section is an area through which the reducing gas blown in through the reducing gas inlet flows, and which also serves as the charging section (descent path) for the iron oxide charged through the iron oxide charging port at the top of the reduction furnace.
  • the reduction section is connected to both the reducing gas inlet and the furnace top gas outlet, forming a path through which the reducing gas (furnace top gas) flows.
  • the reduction section is also connected to both the upper iron oxide charging port and the lower carburizing section, forming a descent path for the iron oxide (reduced iron).
  • the form of the carburizing section is not particularly limited, and a general one can be used.
  • the carburizing section is an area through which carburizing gas blown in from the carburizing gas inlet flows and which serves as a path for the reduced iron obtained from the iron oxide in the reduction section to fall.
  • the carburizing section is connected to the carburizing gas inlet and the carburizing gas outlet, respectively, and forms a path for the carburizing gas to flow.
  • the carburizing section is also connected to the reduction section above and the reduced iron outlet below, respectively, and forms a path for the reduced iron to fall. That is, in one example, the iron oxide charging inlet, reduction section, carburizing section, and reduced iron outlet are arranged in order from top to bottom.
  • the control unit changes the composition of the carburizing gas depending on the composition of the reducing gas, particularly the H 2 /CO ratio of the reducing gas.
  • the preferred control mode in the control unit is as described in [1] above.
  • control unit an input section for inputting measurement data such as various setting values and the composition of the reducing gas; a calculation unit that performs calculation processing on input setting values and measurement data; a storage unit that stores setting values and measurement data; and an output section that outputs an operation signal for changing the composition of the carburizing gas based on the results of the calculation process in the calculation section.
  • measurement data such as various setting values and the composition of the reducing gas
  • calculation unit that performs calculation processing on input setting values and measurement data
  • storage unit that stores setting values and measurement data
  • an output section that outputs an operation signal for changing the composition of the carburizing gas based on the results of the calculation process in the calculation section.
  • control unit is an information processing device.
  • Figure 4 shows an example of a functional block of the control unit.
  • the reduction furnace may have a control unit as shown in Figure 4.
  • the control unit has an input unit and an output unit that are connected to external devices so that they can communicate data with each other, a memory unit that stores various data, and a calculation unit, all of which are connected to each other so that they can communicate data with each other.
  • the input and output units are, for example, interfaces that are capable of data communication with external devices.
  • the calculation unit is, for example, a CPU.
  • the calculation unit controls the operation of the entire control unit.
  • the calculation unit calculates how to change the composition of the carburizing gas based on various set values and measurement data input from the outside to the input unit or stored in the memory unit, and generates an operation signal that changes the composition of the carburizing gas.
  • the output unit outputs this operation signal.
  • the calculation unit achieves the above-mentioned functions by, for example, executing a program stored in the memory unit.
  • the storage unit is, for example, a writable non-volatile memory such as an EPROM.
  • the storage unit is not particularly limited, but can be, for example, an HDD, SSD, etc.
  • the carburizing gas injection device then receives the operation signal output from the output unit, controls the composition of the carburizing gas as described in [1] above, and injects the carburizing gas into the reduction furnace.
  • Numerical analysis model A one-dimensional model in which the area inside the reduction furnace is divided into 40 equal-sized sections in the height direction. Starting from the top of the reduction furnace (the upper side in the height direction of the reduction furnace), the first to 20th sections are set as the reduction section, and the 26th to 40th sections are set as the carburization section.
  • Example 1 In a reducing furnace with a furnace volume of 80 m3 and its associated equipment, as shown schematically in FIG. 1, reduced iron is produced under the conditions listed in Table 1. That is, in Example 1, the carburizing gas composition is changed depending on the reducing gas composition under each condition to produce reduced iron. In particular, the CH4 concentration in the carburizing gas is changed depending on the H2 /( H2 +CO) ratio of the reducing gas so as to satisfy the relationship in equation (7) above. Furthermore, under Condition 5 of Example 1, the amount of carburizing gas injected is also changed so as to satisfy the relationship in equation (8) above. On the other hand, in Comparative Example 1, reduced iron is produced without changing the carburizing gas composition or injection amount under any of the conditions.
  • the operation period was 7 days
  • the reducing gas injection temperature was 980°C
  • the target final carbon content of reduced iron was 2.00 mass%
  • X 0 was 61.7 vol%
  • X 1 was 100 vol%
  • V 0 was 350 Nm 3 /t.
  • the operational parameters are listed in terms of the unit consumption per ton of reduced iron produced. For example, if 1,400 kg of iron oxide pellets are used to produce 1 ton of reduced iron, the amount of iron oxide pellets used is expressed as 1,400 kg/t. If 3,000 t/day of reduced iron is produced, this amount is multiplied by 3,000 to obtain the parameters per day. Note that X0 and V0 are obtained by the preliminary operation test according to the above-mentioned procedure. The amount of iron oxide charged, the reducing gas injection temperature, the reducing gas injection rate, and the reducing gas composition under the base operational conditions are based on the specifications of the reducing furnace used. The same applies to Example 2 described below.
  • Example 1 exhibits excellent control accuracy for the final carbon content of reduced iron.
  • Comparative Example 1 exhibits insufficient control accuracy for the final carbon content of reduced iron.
  • Example 2 In a reducing furnace with a furnace volume of 100 m3 (different from that of Example 1) and its associated equipment, as shown schematically in FIG. 1, reduced iron is produced under the conditions listed in Table 2. That is, in Inventive Example 2, the carburizing gas composition is changed depending on the reducing gas composition under each condition to produce reduced iron. In particular, the CH4 concentration of the carburizing gas is changed depending on the H2 /( H2 +CO) ratio of the reducing gas so as to satisfy the relationship in equation (7) above. Furthermore, under Condition 7 of Inventive Example 2, the amount of carburizing gas injected is also changed so as to satisfy the relationship in equation (8) above. On the other hand, in Comparative Example 2, reduced iron is produced without changing the carburizing gas composition or injection amount under all conditions.
  • the operation period was 7 days
  • the reducing gas injection temperature was 1025°C
  • the target final carbon content of reduced iron was 4.70 mass%
  • X 0 was 75.1 vol%
  • X 1 was 100 vol%
  • V 0 was 424 Nm 3 /t.
  • Example 2 of the present invention has excellent control accuracy for the final carbon content of reduced iron.
  • Comparative Example 2 has insufficient control accuracy for the final carbon content of reduced iron.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Abstract

L'invention concerne un procédé de production de fer réduit, ledit procédé permettant de réguler avec précision la teneur finale en carbone de fer réduit. La composition d'un gaz de cémentation est modifiée en fonction de la composition d'un gaz réducteur.
PCT/JP2025/020840 2024-08-27 2025-06-09 Procédé de production de fer réduit et four de réduction Pending WO2026048209A1 (fr)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55125212A (en) * 1979-03-20 1980-09-26 Nippon Steel Corp Method and apparatus for reducing iron oxide
WO2021029114A1 (fr) * 2019-08-09 2021-02-18 合同会社Ｋｅｓｓ Installation et procédé de production d'éponge de fer

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55125212A (en) * 1979-03-20 1980-09-26 Nippon Steel Corp Method and apparatus for reducing iron oxide
WO2021029114A1 (fr) * 2019-08-09 2021-02-18 合同会社Ｋｅｓｓ Installation et procédé de production d'éponge de fer

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