Smelting reduction furnace
By designing a melt reduction furnace including the main furnace body and the front furnace cylinder, the gas pressure in the furnace and the liquid level of the slag iron are improved, the problems of environmental pollution and high energy consumption in the non-blast furnace melt reduction ironmaking process are solved, and the effect of reducing carbon emissions and increasing yield is achieved.
Patent Information
- Application Number
- CN202510006623.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-03
- Publication Date
- 2025-04-08
AI Technical Summary
The non-blast furnace melt reduction ironmaking process has problems of environmental pollution and high energy consumption in terms of reducing agent replacement and energy consumption reduction.
A melt reduction furnace including the main furnace body and the front furnace cylinder is designed. By increasing the gas pressure in the furnace and increasing the iron port of the front furnace cylinder, the slag iron liquid level height and the working condition volume density of the gas in the furnace are optimized to improve the yield and reduce the coal ratio.
It has achieved the reduction of carbon emissions, increased the yield of melt reduction iron smelting and reduced coal ratio, thus solving the problems of high energy consumption and environmental pollution.
Smart Images
Figure CN119776604A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of smelting reduction ironmaking, and in particular to a smelting reduction furnace. Background Art
[0002] The non-blast furnace smelting reduction ironmaking process has gradually been recognized and promoted by the industry, but usually the non-blast furnace smelting reduction ironmaking process still uses coal powder or coke powder as a reducing agent. At present, attempts have been made to inject hydrogen and biomass charcoal to replace coal powder or coke powder as reducing agents. Although the carbon emissions are much reduced compared to the traditional blast furnace ironmaking process, there are still more CO2, CO and H2S emissions, which still cause great pollution to the environment and climate. Moreover, how to reduce the energy consumption per unit process of smelting reduction ironmaking is also an urgent problem to be solved in the smelting reduction ironmaking process. Summary of the invention
[0003] In order to solve the above problems, the present application provides a smelting reduction furnace.
[0004] The present application provides a smelting reduction furnace, comprising a main furnace body and a front furnace cylinder. The main furnace body is provided with a molten iron zone and a reduction zone located above the molten iron zone. The reduction zone is used for reduction reaction of iron ore powder, and the molten iron zone is used for accommodating molten iron. The front furnace cylinder and the main furnace body are connected to the molten iron zone. The front furnace cylinder is provided with an iron mouth, and the iron mouth is higher than the reduction zone.
[0005] In some embodiments, the main furnace body is equipped with an original front furnace hearth, which is an improved front furnace, and the front furnace hearth is relatively 1m-3m higher than the original front furnace.
[0006] In some embodiments, the height of the iron mouth is 4m-6m.
[0007] In some embodiments, the smelting reduction furnace further comprises:
[0008] A mixing gun, connected to the main furnace body and with a gun head disposed in the reduction zone;
[0009] A pulverized coal spray gun is connected to the main furnace body and the gun head is arranged in the reduction zone;
[0010] The hot air spray gun is installed through the main furnace body and the gun head is higher than the reduction zone.
[0011] In some embodiments, a connecting channel is provided at the bottom of the main furnace body, one end of the connecting channel is connected to the molten iron area, and the other end of the connecting channel is connected to the front furnace.
[0012] In some embodiments, the main furnace body is provided with a slag opening, and the slag opening is arranged at the same height as the upper edge of the reduction zone.
[0013] In some embodiments, the slag hole is used for discharging molten slag intermittently in batches.
[0014] In some embodiments, the smelting reduction furnace further comprises:
[0015] The coal gas outlet is opened in the main furnace body and is higher than the gun head of the hot air spray gun. The coal gas outlet is used to continuously discharge the coal gas generated in the reduction reaction in the reduction zone.
[0016] In some embodiments, the hot air spray gun is used to spray high-pressure oxygen-rich hot air into the main furnace body. The high-pressure oxygen-rich hot air has a temperature of 1150°C to 1250°C, an oxygen content of 35% to 45%, and a hot air pressure of 0.08MPa to 0.25MPa.
[0017] In some embodiments, the temperature of the coal gas generated by the reduction reaction of the iron ore powder in the reduction zone is 1400°C to 1600°C, the coal gas pressure is 0.08MPa to 0.25MPa, and the dust content is 10 to 20g / Nm 3 .
[0018] The beneficial effects of the present application are as follows: a smelting reduction furnace is provided, comprising a main furnace body and a front furnace cylinder, the main furnace body is provided with a molten iron zone and a reduction zone, the reduction zone is located above the molten iron zone, the preheated iron ore powder, granular coal and flux undergo reduction reaction in the reduction zone, the molten iron formed by reduction flows downward into the molten iron zone, the front furnace cylinder and the main furnace body are connected to the molten iron zone, under the action of pressure, the molten iron can enter the front furnace cylinder lined with refractory material, an iron mouth is provided in the front furnace cylinder, the molten iron is siphoned out through the iron mouth, and since the iron mouth of the front furnace cylinder is higher than the reduction zone of the main furnace cylinder, compared with the traditional smelting reduction furnace, the present application increases the height of the front furnace cylinder and increases the iron mouth of the front furnace cylinder The smelting reduction furnace provided in the present application can increase the gas pressure in the furnace of the main furnace body while increasing the pressure in the furnace of the smelting reduction furnace. Because the front furnace cylinder is designed to be higher and the iron mouth of the front furnace cylinder is moved upward, the slag and iron liquid level in the main furnace body can be maintained relatively unchanged under the pre-designed state. The beneficial effect is that the working volume density of the gas in the smelting reduction furnace is increased, which is beneficial to the three-transmission and one-reverse process in the smelting reduction furnace, thereby achieving the effect of increasing production and reducing coal ratio, thereby reducing carbon emissions in the process of smelting reduction ironmaking. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.
[0020] Figure 1 A schematic diagram of the structure of a smelting reduction furnace provided in this application.
[0021] The attached drawings are marked with: 10-main furnace body, 11-molten iron area, 12-reduction area, 13-mixing gun, 14-coal powder spray gun, 15-hot air spray gun, 16-connecting channel, 17-slag outlet, 18-gas outlet, 20-front furnace, 21-iron mouth. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0023] In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides various specific examples of processes and materials, but those of ordinary skill in the art may recognize the application of other processes and / or the use of other materials.
[0024] In the iron-making process of traditional blast furnaces in steel mills, a total of about 500 kilograms of coke and pulverized coal are used to smelt each ton of pig iron. Both coke and pulverized coal are fossil energy sources, which ultimately produce a large amount of greenhouse gas carbon emissions, causing serious environmental pollution.
[0025] The non-blast furnace smelting reduction ironmaking process has gradually been recognized and promoted by the industry, but usually the non-blast furnace smelting reduction ironmaking process still uses coal powder or coke powder as a reducing agent. At present, attempts have been made to inject hydrogen and biomass charcoal to replace coal powder or coke powder as reducing agents. Although the carbon emissions are much reduced compared to the traditional blast furnace ironmaking process, there are still more CO2, CO and H2S emissions, which still cause great pollution to the environment and climate. How to reduce the energy consumption per unit process of smelting reduction ironmaking is also an urgent problem to be solved in the smelting reduction ironmaking process.
[0026] When the smelting reduction furnace is in normal production, the preheated iron ore powder, granular coal and flux are sprayed into the molten iron pool through the mixture spray gun, carbon is melted into the molten iron, the iron oxide in the charge is reduced to CO and molten iron by the dissolved carbon, and the gangue in the iron ore, the flux and the ash in the coal powder are fused into slag. The molten iron and slag are quickly sprayed up and down by the rapidly released CO, H2 and N2 (CO2) used as a carrier in the molten pool, forming a spring. At the same time, the coal gas generated during the smelting process is secondary burned with the oxygen-rich hot air in the upper part of the smelting reduction furnace to produce high-temperature flue gas. When the molten iron and slag droplets in the spring come into contact with the high-temperature flue gas, the heat is transferred to the molten pool by radiation and convection, which greatly promotes the heat transfer from the upper space to the molten pool, thereby maintaining the temperature of the molten iron in the molten pool and continuing the smelting reduction reaction. The smelting reduction furnace is connected with the front furnace at the bottom of the furnace cylinder. The molten iron produced by the smelting reduction furnace enters the front furnace cylinder lined with refractory materials and is siphoned out. The slag is discharged in batches through the water-cooled slag outlet, and the high-temperature and high-pressure coal gas is continuously discharged through the coal gas outlet on the smelting reduction furnace.
[0027] Through research, it is found that if the pressure of the oxygen-enriched hot air is further increased, thereby increasing the pressure inside the smelting reduction furnace and the operating volume density of the gas inside the smelting reduction furnace, it will be beneficial to the momentum transfer, heat transfer and mass transfer inside the smelting reduction furnace, promote the iron oxide reduction reaction process, and be beneficial to the three-transmission and one-reverse process inside the smelting reduction furnace, thereby achieving the effect of increasing production and reducing the coal ratio, thereby reducing carbon emissions in the smelting reduction ironmaking process.
[0028] However, the discharge of molten iron from the front furnace cylinder is caused by the pressure difference between the main furnace body and the front furnace cylinder of the smelting reduction furnace. The combined pressure on the main furnace body side of the smelting reduction furnace is large, while the combined pressure on the front furnace cylinder side is small. The molten iron will flow from one side of the main furnace body of the smelting reduction furnace to the other side of the front furnace cylinder until the combined pressure on both sides is equal. Then the molten iron will stop flowing and the molten iron in the smelting reduction furnace can be discharged by utilizing the siphon phenomenon.
[0029] If the pressure of the oxygen-rich hot air in the main furnace body of the smelting reduction furnace is further increased, the furnace pressure of the smelting reduction furnace can be increased, but the height of the slag iron liquid level in the smelting reduction furnace will be reduced, which is not conducive to the slag iron storage and the "three transmission and one reverse" process of the smelting reduction furnace.
[0030] Please refer to Figure 1The present application provides a smelting reduction furnace, including a main furnace body 10 and a front furnace cylinder 20. The main furnace body 10 is provided with a molten iron zone 11 and a reduction zone 12. The reduction zone 12 is located above the molten iron zone 11. Preheated iron ore powder, granular coal and flux are sprayed into the main furnace body 10, and a reduction reaction is carried out in the reduction zone 12. The high-temperature molten iron formed by the reduction flows downward into the molten iron zone 11. The molten iron is stored in the molten iron zone 11 located at the bottom of the main furnace body 10. The front furnace cylinder 20 is connected to the main furnace body 10, and the front furnace cylinder 20 is connected to the molten iron zone 11. Under the action of pressure, the molten iron can enter the front furnace cylinder 20 lined with refractory material. An iron mouth 21 is provided in the front furnace cylinder 20, and the molten iron is siphoned out through the iron mouth 21.
[0031] In the present application, the iron mouth 21 of the front furnace 20 is set higher than the reduction zone 12 of the main furnace body 10. Compared with the traditional smelting reduction furnace, the smelting reduction furnace provided in the present application is equivalent to increasing the height of the front furnace 20 and moving the iron mouth 21 of the front furnace 20 upward. Therefore, compared with the working state of the traditional smelting reduction furnace for smelting reduction ironmaking, the smelting reduction furnace provided in the present application can increase the gas pressure in the furnace of the main furnace body 10, and while increasing the pressure in the furnace of the smelting reduction furnace, the height of the slag iron liquid level in the main furnace body 10 can be maintained unchanged relative to the slag iron liquid level of the traditional smelting reduction furnace due to the heightening design of the front furnace 20 and the upward movement of the iron mouth 21 of the front furnace 20. The beneficial effects of the relatively unchanged height of the slag iron liquid level in the main furnace body 10 include but are not limited to the fact that the various components of the main furnace body 10 do not need to be changed, and the existing main furnace body 10 can be used, and only the front furnace 20 of the existing smelting reduction furnace needs to be replaced.
[0032] The smelting reduction furnace provided in the present application can increase the gas pressure in the furnace and can maintain the slag and iron liquid level in the main furnace body 10 relatively unchanged. The beneficial effect is that the working volume density of the gas in the smelting reduction furnace is improved, which is beneficial to the three-transmission and one-reverse process in the smelting reduction furnace, thereby achieving the effect of increasing production and reducing coal ratio, thereby reducing carbon emissions in the smelting reduction ironmaking process.
[0033] It should be noted that in order to maintain the slag iron liquid level in the main furnace body 10 unchanged relative to the slag iron liquid level in the traditional smelting reduction furnace, the height change of the iron mouth 21 of the front furnace 20 needs to be specifically designed. Here is an example to illustrate that the pressure in the furnace of the existing traditional smelting reduction furnace in the factory is 0.8kg / cm 2 , pressure 1kg / cm 2 The slag iron liquid level of the smelting reduction furnace is at the height h1. When designing the height of the iron mouth 21 of the front furnace 20 in this application, it has been considered that the pressure in the furnace of the main furnace body 10 during production is increased to a set value, such as 2.5 kg / cm 2That is 0.25MPa. Under the condition of maintaining the slag and iron liquid level h1 of the smelting reduction furnace, the height of the iron mouth 21 of the front furnace 20 can be smoothly calculated in combination with the density values of various materials during production.
[0034] The density of each material in the smelting reduction furnace during production refers to the density of the molten iron and the density of the material in the reduction zone 12. The material in the reduction zone 12 includes but is not limited to slag, and the density of the slag is 2.4g / cm 3 .
[0035] On the basis of the original pre-furnace of the smelting reduction furnace, the pre-furnace 20 in the present application belongs to an improved pre-furnace. In some embodiments, the pre-furnace 20 is relatively 1m-3m higher than the original pre-furnace, and ensures that the upper edge height of the reduction zone 12 during smelting reduction ironmaking is unchanged compared to the slag liquid level h1 height of the original smelting reduction furnace during production. The upper edge height of the reduction zone 12 is also the slag liquid level height in the furnace during production. The increase of 1m-3m in the pre-furnace 20 in the present embodiment is calculated based on existing production conditions.
[0036] In some embodiments, based on the original production conditions of the smelting reduction furnace, the iron mouth height of the original pre-furnace is 3m, and the corresponding pressure in the furnace is 0.08MPa; when the pressure in the furnace is increased from 0.08MPa to ~0.25MPa, the corresponding iron mouth height is increased from the original 3m to 1m-3m, and therefore the height of the iron mouth 21 in the smelting reduction furnace provided in this application is limited to 4m-6m.
[0037] In some embodiments, see Figure 1 The smelting reduction furnace includes a mixing gun 13, a pulverized coal spray gun 14 and a hot air spray gun 15. The mixing gun 13 is connected to the main furnace body 10, and the gun head of the mixing gun 13 is arranged in the reduction zone 12. The preheated iron ore powder and flux are sprayed into the reduction zone 12 of the main furnace body 10 through the mixing gun 13. The pulverized coal spray gun 14 is connected to the main furnace body 10, and the gun head of the pulverized coal spray gun 14 is arranged in the reduction zone 12. The granular coal is sprayed into the reduction zone 12 of the main furnace body 10 through the pulverized coal spray gun 14. The hot air spray gun 15 is penetrated through the main furnace body 10, and the gun head of the hot air spray gun 15 is higher than the reduction zone 12. The hot air spray gun 15 is generally installed on the top of the main furnace body 10 and installed vertically. The high-pressure oxygen-enriched hot air is sprayed into the main furnace body 10 through the hot air spray gun 15.
[0038] In some embodiments, see Figure 1 The main furnace body 10 is provided with a connecting channel 16, which is located at the bottom of the main furnace body 10. One end of the connecting channel 16 is connected to the molten iron area 11, and the other end of the connecting channel 16 is connected to the front furnace cylinder 20. The high-temperature molten iron enters the front furnace cylinder 20 through the connecting channel 16.
[0039] In some embodiments, see Figure 1 The main furnace body 10 is provided with a slag outlet 17, which is arranged at the upper edge of the reduction zone 12. The upper edge of the reduction zone 12 refers to the slag iron liquid level in the furnace during production. The high-temperature molten slag generated by the main furnace body 10 is discharged intermittently in batches from the slag outlet 17.
[0040] In some embodiments, the molten reduction furnace is provided with a gas outlet 18 , which is opened in the main furnace body 10 and is higher than the gun head of the hot air spray gun 15 . The high-temperature and high-pressure gas generated by the main furnace body 10 in the reduction reaction is continuously discharged from the gas outlet 18 .
[0041] The present application also provides specific parameters of the smelting reduction furnace during production, wherein the iron ore powder is preheated to a temperature greater than or equal to 600°C, the particle size of the iron ore powder is 0-10mm, the particle size of the flux is less than 3mm, the particle size of the granular coal is less than 3mm, the state of the high-pressure oxygen-enriched hot air sprayed into the main furnace body 10 is a temperature of 1150°C to 1250°C, an oxygen content of 35% to 45%, and a hot air pressure of 0.08MPa to 0.25MPa, the preheated iron ore powder, flux, granular coal and high-pressure oxygen-enriched hot air are sprayed into the main furnace body 10 together, and the iron ore powder is subjected to a reduction reaction in the reduction zone 12 to produce high-temperature molten iron of 1350°C to 1500°C, high-temperature slag of 1400°C to 1550°C, and high-temperature and high-pressure raw coal gas of 1400°C to 1600°C, the pressure of the high-temperature and high-pressure raw coal gas is 0.08MPa to 0.25MPa, and the dust content of the high-temperature and high-pressure raw coal gas is 10 to 20g / Nm 3 .
[0042] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0043] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.
[0044] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A smelting reduction furnace, characterized in that: include: The main furnace body is provided with a molten iron zone and a reduction zone located above the molten iron zone, wherein the reduction zone is used for the reduction reaction of iron ore powder, and the molten iron zone is used for containing molten iron; The front furnace is connected to the molten iron zone with the main furnace, and the front furnace is provided with an iron mouth, which is higher than the reduction zone.
2. The smelting reduction furnace according to claim 1, characterized in that: The main furnace body is equipped with an original front furnace cylinder, which is an improved front furnace. The front furnace cylinder is relatively 1m-3m higher than the original front furnace.
3. The smelting reduction furnace according to claim 2, characterized in that: The height of the iron mouth is 4m-6m.
4. The smelting reduction furnace according to any one of claims 1 to 3, characterized in that: The smelting reduction furnace also includes: A mixing gun, connected to the main furnace body and having a gun head disposed in the reduction zone; A pulverized coal spray gun, connected to the main furnace body and having a gun head disposed in the reduction zone; A hot air spray gun is disposed through the main furnace body and a gun head is higher than the reduction zone.
5. The smelting reduction furnace according to claim 4, characterized in that: The main furnace body is provided with a connecting channel at the bottom, one end of the connecting channel is communicated with the molten iron area, and the other end of the connecting channel is communicated with the front furnace.
6. The smelting reduction furnace according to claim 4, characterized in that: The main furnace body is provided with a slag opening, and the slag opening is arranged at the upper edge of the reduction zone.
7. The smelting reduction furnace according to claim 6, characterized in that: The slag outlet is used for discharging molten slag intermittently in batches.
8. The smelting reduction furnace according to claim 4, characterized in that: The smelting reduction furnace is also provided with: A gas outlet is provided in the main furnace body and is higher than the gun head of the hot air spray gun. The gas outlet is used to continuously discharge the gas generated in the reduction reaction in the reduction zone.
9. The smelting reduction furnace according to claim 4, characterized in that: The hot air spray gun is used to spray high-pressure oxygen-enriched hot air into the main furnace body. The temperature of the high-pressure oxygen-enriched hot air is 1150° C. to 1250° C., the oxygen content is 35% to 45%, and the hot air pressure is 0.08 MPa to 0.25 MPa.
10. The smelting reduction furnace according to claim 9, characterized in that: The temperature of the coal gas generated by the reduction reaction of the iron ore powder in the reduction zone is 1400°C to 1600°C, the coal gas pressure is 0.08MPa to 0.25MPa, and the dust content is 10 to 20g / Nm 3 .