Smelting reduction furnace

Abstract

The invention discloses a smelting reduction furnace and relates to the technical field of smelting reduction ironmaking, the smelting reduction furnace comprises a main furnace body and a front hearth, the main furnace body comprises a molten iron area used for containing molten iron, the front hearth is provided with an iron notch, the iron notch is blocked by stemming, and the iron notch is used for intermittently discharging the molten iron in batches; a furnace cover is installed on the top of the front hearth in a sealed mode, and the front hearth and the main furnace body are communicated with the molten iron area. According to the scheme, the slag iron liquid level height of the main furnace body during production can be kept unchanged as much as possible compared with the slag iron liquid level height of the main furnace body when the pressure in the furnace is not increased, the three-transmission and one-reaction process in the smelting reduction furnace is facilitated by increasing the working condition volume density of gas in the smelting reduction furnace, the effects of increasing the yield and reducing the coal ratio are achieved, and the production cost is reduced. And therefore, the carbon emission in the smelting reduction ironmaking process is reduced.

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 comprising a molten iron area for accommodating molten iron, the front furnace cylinder is provided with an iron mouth and the iron mouth is sealed by taphole mud, the iron mouth is used to discharge the molten iron intermittently and in batches, the front furnace cylinder is sealed with a furnace cover at the top, and the front furnace cylinder and the main furnace body are connected to the molten iron area.

[0005] In some embodiments, the main furnace body further includes a reduction zone located above the molten iron zone, the reduction zone is used for the reduction reaction of the iron ore powder, and the furnace cover is lower than the upper edge of the reduction zone.

[0006] In some embodiments, the smelting reduction furnace further comprises:

[0007] A mixing gun, connected to the main furnace body and with a gun head disposed in the reduction zone;

[0008] A pulverized coal spray gun is connected to the main furnace body and the gun head is arranged in the reduction zone;

[0009] The hot air spray gun is installed through the main furnace body and the gun head is higher than the reduction zone.

[0010] In some embodiments, the smelting reduction furnace further comprises:

[0011] 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.

[0012] 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.

[0013] 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 .

[0014] In some embodiments, the mixing gun is used to spray iron ore powder having a preheated temperature of not less than 600° C. and a particle size of less than 10 mm and a flux having a particle size of less than 3 mm into the reduction zone;

[0015] The pulverized coal spray gun is used to spray coal particles with a particle size of less than 3mm into the reduction zone.

[0016] 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.

[0017] In some embodiments, the slag hole is used to discharge the molten slag intermittently and in batches.

[0018] In some embodiments, the main furnace body is provided with a connecting channel at the bottom, 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.

[0019] 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, the molten iron zone is located at the bottom of the main furnace body, high-temperature molten iron generated by the reduction reaction of preheated iron ore powder, granular coal and flux flows downward into the molten iron zone, the front furnace cylinder and the main furnace body are connected to the molten iron zone, the molten iron can enter the front furnace cylinder lined with refractory material under pressure, the front furnace cylinder is sealed with a furnace cover at the top, the furnace cover can seal the top furnace mouth of the front furnace cylinder, the front furnace cylinder is provided with an iron mouth, the iron mouth is sealed with tapping mud, the iron mouth is regularly unblocked, and the molten iron is discharged intermittently in batches; Since the present application adds a furnace cover to seal the front furnace cylinder, the furnace pressure of the main furnace body can be increased while keeping the furnace pressure of the main furnace body equal to that of the front furnace cylinder. When molten iron is not needed, the iron mouth is blocked with taphole mud, so that the slag and iron liquid level of the main furnace body during production can be maintained as unchanged as possible compared to the slag and iron liquid level of the main furnace body when the furnace pressure is not increased. By increasing the working volume density of the gas in the molten reduction furnace, it is beneficial to the three-transmission and one-reversal process in the molten reduction furnace, thereby achieving the effect of increasing production and reducing coal ratio, thereby reducing carbon emissions in the molten reduction ironmaking process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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.

[0021] Figure 1 A schematic diagram of the structure of a smelting reduction furnace provided in this application.

[0022] 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-gas outlet, 17-slag outlet, 18-connecting channel, 20-front furnace, 21-iron mouth, 22-furnace cover. DETAILED DESCRIPTION

[0023] 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 creative work are within the scope of protection of this application.

[0024] 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.

[0025] In the iron-making process, traditional blast furnaces in steel mills use a total of about 500 kilograms of coke and pulverized coal to smelt each ton of pig iron. Both coke and coal are fossil energy sources, which ultimately produce large amounts of greenhouse gas carbon emissions, causing significant environmental pollution.

[0026] 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.

[0027] 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 hearth at the bottom of the main furnace body. The molten iron produced by the smelting reduction furnace enters the iron mouth on the front hearth lined with refractory material and is discharged intermittently in batches. The slag is discharged in batches through the water-cooled slag mouth, and the high-temperature and high-pressure coal gas is continuously discharged through the coal gas outlet on the smelting reduction furnace.

[0028] 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.

[0029] To this end, the present application provides a smelting reduction furnace, please refer to Figure 1 The smelting reduction furnace includes a main furnace body 10 and a front furnace 20. The main furnace body 10 is provided with a molten iron area 11, which is located at the bottom of the main furnace body 10. The high-temperature molten iron generated by the reduction reaction of the preheated iron ore powder, granular coal and flux flows downward into the molten iron area 11, and the high-temperature molten iron is stored in the molten iron area 11.

[0030] The front furnace 20 is connected to the main furnace body 10, and the front furnace 20 is connected to the molten iron area 11. Under pressure, molten iron can enter the front furnace 20 lined with refractory materials. The front furnace 20 is sealed with a furnace cover 22 at the top. The sealed installation here means that the furnace cover 22 can seal the top furnace mouth of the front furnace 20 in the installed state. The front furnace 20 is provided with an iron mouth 21, which is blocked with tapping mud. The iron mouth is opened and blocked regularly, and molten iron is discharged intermittently and in batches from the iron mouth 21 of the front furnace 20.

[0031] The smelting reduction furnace provided in the present application is additionally provided with a furnace cover 22, by which the front furnace cylinder 20 is covered and sealed, so that the furnace pressure of the main furnace body 10 can be increased while the furnace pressure of the main furnace body 10 is kept equal to the furnace pressure of the front furnace cylinder 20. When molten iron is not needed to be discharged, the iron mouth 21 will be blocked with tapping mud.

[0032] When oxygen-enriched hot air is introduced into the main furnace body 10, the slag iron liquid level of the main furnace body 10 is at a first height value during smelting reduction production. The smelting reduction furnace of the present application can further increase the pressure of the oxygen-enriched hot air. At this time, the pressure in the furnace increases, but because the iron mouth 21 is blocked and the top furnace mouth of the front furnace cylinder 20 is sealed, the slag iron liquid level of the main furnace body 10 can be maintained at the first height value as much as possible, and the slag iron liquid level of the main furnace body 10 during production is maintained as unchanged as possible compared to the slag iron liquid level of the main furnace body 10 when the pressure in the furnace is not increased, thereby solving the problem that the slag iron liquid level of the traditional smelting reduction furnace will be reduced when the pressure of the oxygen-enriched hot air is increased, which is not conducive to the slag iron storage and the process of "three transmissions and one reverse" of the smelting reduction furnace.

[0033] The smelting reduction furnace provided in the present application, by increasing the operating volume density of the gas in the smelting reduction furnace, is beneficial to the three-transmission-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.

[0034] In some embodiments, see Figure 1 The main furnace body 10 is provided with a connecting channel 18, and the connecting channel 18 is located at the bottom of the connecting channel 18. One end of the connecting channel 18 is connected to the molten iron area 11, and the other end of the connecting channel 18 is connected to the front furnace 20. The high-temperature molten iron enters the front furnace 20 through the connecting channel 18.

[0035] In some embodiments, see Figure 1 The main furnace body 10 is also provided with a reduction zone 12, which is located above the molten iron zone 11. The 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, and the molten iron is stored in the molten iron zone 11 located at the bottom of the main furnace body 10. In addition, please refer to Figure 1 The furnace cover 22 is lower than the upper edge of the reduction zone 12. The upper edge of the reduction zone 12 is the slag and iron liquid level in the main furnace body 10 during production. The slag and iron liquid level fluctuates during production.

[0036] In some embodiments, see Figure 1The smelting reduction furnace further 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 disposed 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 disposed 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 disposed 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 at the top of the main furnace body 10 and is installed vertically. The high-pressure oxygen-enriched hot air is sprayed into the main furnace body 10 through the hot air spray gun 15.

[0037] In some embodiments, see Figure 1 The smelting reduction furnace is also provided with a gas outlet 16 , 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 16 .

[0038] In some embodiments, see Figure 1 The main furnace body 10 is provided with a slag outlet 17, which is arranged at the same height as the upper edge of the reduction zone 12. The upper edge of the reduction zone 12 is the slag liquid level in the main furnace body 10 during production. The high-temperature molten slag generated in the main furnace body 10 is discharged intermittently in batches from the slag outlet 17.

[0039] The present application also provides specific parameters of the smelting reduction furnace during production, specifically, the iron ore powder is preheated to 600°C or more, 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 1150°C-1250°C, the oxygen content is 35%-45%, and the hot air pressure is 0.08MPa-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-1500°C, high-temperature slag of 1400°C-1550°C and high-temperature and high-pressure raw coal gas of 1400°C-1600°C, the gas pressure of the high-temperature and high-pressure raw coal gas is 0.08MPa-0.25MPa, and the dust content of the high-temperature and high-pressure raw coal gas is 10-20g / Nm 3 .

[0040] The high-temperature molten iron at 1350℃~1500℃ in the molten iron area 11 enters the front hearth 20 for storage through the connecting channel 18. The high-temperature molten iron stored in the front hearth 20 is discharged intermittently in batches from the iron mouth, the high-temperature slag at 1400℃~1550℃ produced by the reduction reaction is discharged intermittently in batches from the slag mouth, and the high-temperature and high-pressure coal gas produced by the reduction reaction is continuously discharged from the gas outlet.

[0041] 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.

[0042] 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.

[0043] 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: A main furnace body, including a molten iron area for containing molten iron; The front furnace is provided with an iron mouth which is blocked by taphole mud. The iron mouth is used to discharge molten iron intermittently and in batches. A furnace cover is sealed at the top of the front furnace. The front furnace and the main furnace body are connected to the molten iron area.

2. The smelting reduction furnace according to claim 1, characterized in that: The main furnace body also includes a reduction zone located above the molten iron zone, the reduction zone is used for the reduction reaction of iron ore powder, and the furnace cover is lower than the upper edge of the reduction zone.

3. The smelting reduction furnace according to claim 2, 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.

4. The smelting reduction furnace according to claim 3, 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.

5. The smelting reduction furnace according to claim 3, 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.

6. The smelting reduction furnace according to claim 5, 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 .

7. The smelting reduction furnace according to claim 3, characterized in that: The mixing gun is used to spray iron ore powder with a preheated temperature of not less than 600° C. and a particle size of less than 10 mm and flux with a particle size of less than 3 mm into the reduction zone; The pulverized coal spray gun is used to spray granular coal with a particle size less than 3 mm into the reduction zone.

8. The smelting reduction furnace according to claim 2, characterized in that: 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.

9. The smelting reduction furnace according to claim 8, characterized in that: The slag outlet is used for discharging molten slag intermittently and in batches.

10. The smelting reduction furnace according to claim 1, 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.

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