Furnace burden structure of hydrogen-rich carbon circulating oxygen blast furnace and material distribution method

Abstract

The invention belongs to the technical field of steel rolling production, and particularly discloses a furnace charge structure and a distribution method of a hydrogen-rich carbon circulating oxygen blast furnace, and the furnace charge structure and the distribution method of the hydrogen-rich carbon circulating oxygen blast furnace are characterized in that mineral aggregates comprise 20-40% of high-alkalinity sintered materials, 5-10% of scrap steel, 1-1.5% of coke nuts, 60-80% of acidic pellets and 5-20% of vanadium-titanium pellets; in the shutdown preparation stage before blast furnace overhaul, the adding amount of the high-alkalinity sintered material is adjusted to be 20-30%, and the adding amount of the acid pellet ore is adjusted to be 70-80%; in the starting recovery stage after the blast furnace is overhauled, the adding amount of the high-alkalinity sintered material, the scrap steel and the nut coke is set to be 20%, the adding amount of the acid pellets and the vanadium-titanium pellets is set to be 80%, the blast capacity in the furnace is gradually increased to the normal blast capacity of the corresponding blast furnace scale, and the mineral aggregate is adjusted according to the blast capacity in the furnace. The high-alkalinity sintered material, the waste steel, the coke nuts, the acid pellets and the vanadium-titanium pellets are matched, so that the reduction effect and the air permeability of a medium-low temperature area in the blast furnace can be ensured, and the problem of sintering reduction caused by high-reducibility coal gas of the hydrogen-rich carbon circulating oxygen blast furnace is solved.

Description

Technical Field

[0001] The invention relates to the technical field of steel rolling production, and in particular to a charge structure and a charge distribution method for a hydrogen-rich carbon circulating oxygen blast furnace. Background Art

[0002] At present, carbon emissions from blast furnace ironmaking processes account for more than 70% of carbon emissions from the steel and metallurgical industry. Traditional blast furnaces have developed into extremely efficient reactors today. However, traditional blast furnaces need to consume a large amount of coke to supplement the heat required for iron oxide reduction and soft melting. Traditional blast furnace ironmaking fuel has reached its limit. The emergence of hydrogen-rich carbon circulating oxygen blast furnaces has achieved major technological breakthroughs in traditional blast furnace full oxygen smelting, top gas decarbonization and heating and recycling, and hydrogen-rich metallurgical technology, enabling traditional blast furnaces to have a carbon emission reduction capacity of more than 30%.

[0003] However, any slight discrepancy in the ore distribution structure of the hydrogen-rich carbon circulating oxygen blast furnace may interfere with the permeability and reduction process in the furnace. At the same time, the ore distribution ratio needs to be precisely controlled. Once the ore supply is unstable and the composition fluctuates, it will cause an imbalance in the proportion and reduce the strength of the sintered ore, thereby increasing the low-temperature reduction pulverization rate. The slag properties, molten iron composition, blast furnace permeability, etc. will all be adversely affected, and it will cause various elements in the molten iron to be difficult to control, causing foamy slag, slag viscosity, etc. Therefore, a charge structure and method that can stabilize the blast furnace combustion reaction is needed. Summary of the invention

[0004] The object of the present invention is to provide a charge structure and a charge distribution method for a hydrogen-rich carbon-circulating oxygen blast furnace, so as to solve the problem that in the ore distribution process of the hydrogen-rich carbon-circulating oxygen blast furnace, once the ore supply is unstable and the composition fluctuates, it will cause an imbalance in the proportions, reduce the strength of the sintered ore, thereby increasing the low-temperature reduction pulverization rate, and adversely affecting the slag properties, molten iron composition, blast furnace permeability, etc.

[0005] In order to achieve the above object, the basic scheme provided by the present invention is: a charge structure of a hydrogen-rich carbon circulating oxygen blast furnace, comprising: During the normal production stage of the blast furnace, the proportion of the ore is set as follows: 20-40% high-basicity sintering material, 5-10% scrap steel, 1-1.5% coke, 60-80% acidic pellets and 5-20% vanadium-titanium pellets; In the shutdown preparation stage before blast furnace maintenance, the addition amount of high basicity sintering material is adjusted to 20-30%, and the addition amount of acidic pellets is adjusted to 70-80%; During the startup and recovery phase after the blast furnace overhaul, the addition amount of high-alkalinity sintering material, scrap steel and coke is set to 20%, and the addition amount of acidic pellets and vanadium-titanium pellets is set to 80%. The air volume entering the furnace is gradually increased to the normal air volume corresponding to the scale of the blast furnace, and the ore is adjusted according to the air volume entering the furnace.

[0006] The principle and beneficial effect of the present invention are as follows: a large amount of acidic pellets are used, the characteristics of high strength and high air permeability of acidic pellets at low temperature (200-850°C) are better utilized, and the acidic pellets are matched with high-basicity sintering materials to ensure the reduction effect and air permeability in the medium and low temperature areas of the blast furnace. The coke produced by the blast furnace and the high-basicity sintering materials are mixed into the furnace. The coke with good strength can well solve the influence of partial reduction and pulverization of the high-basicity sintering materials on the air permeability. The physicochemical properties of the acidic pellets with excellent strength at medium and low temperatures, the scrap steel with excellent strength at medium temperatures, and the coke with excellent strength at high temperatures are utilized to solve the sintering reduction problem caused by the high-reducing coal gas of the hydrogen-rich carbon circulating oxygen blast furnace.

[0007] Option 2, which is the preferred basic option, controls the mass ratio of CaO to SiO2 in the high basicity sintering material to between 2.2-2.6, controls the MgO content in the high basicity sintering material to 2-2.5%, and controls the FeO content to above 9.5%. Controlling the FeO content of the high basicity sintering material to 9.5% can curb the reduction and pulverization of the sintered ore, and the reduction and pulverization rate of the high basicity sintered ore with a mass ratio of CaO to SiO2 of 2.2-2.6 is relatively low, which can adapt to the characteristics of the high-reducibility coal gas component of the hydrogen-rich carbon cycle oxygen blast furnace.

[0008] Scheme 3 is the preferred basic scheme. In the preparation stage before the blast furnace is shut down and the recovery stage after the blast furnace is started, the CO+H2 content in the reducing gas in the furnace is detected by using instruments. According to the detected CO+H2 content, corresponding nitrogen is added to the circulating gas to control the CO+H2 content in the reducing gas in the furnace to ≤50%. Adding nitrogen to reduce the CO+H2 ratio in the reducing gas in the furnace can prevent the sintering reduction powdering caused by the high reducing gas from making it difficult to restore the furnace condition. After the blast furnace is running normally, stop the nitrogen addition measures for the circulating gas.

[0009] Scheme 4 is the preferred basic scheme. The specific method of adjusting the proportion of ore materials according to the air volume entering the furnace is as follows: When the air volume into the furnace is restored to 70% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke is increased to 30%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 70%; When the air volume into the furnace is restored to 80% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke is increased to 35%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 65%; When the air volume entering the furnace is restored to 90% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke will be increased to 40%, and the addition of acidic pellets and vanadium-titanium pellets will be reduced to 60%.

[0010] If the air volume is insufficient, the coke cannot be fully burned, and the heat and reducing gas generated are limited; if the air volume is too large, the excess heat will be lost. By adjusting the amount of ore added to match the air volume, the energy released by the combustion of the ore can be fully utilized, improving energy efficiency.

[0011] Scheme 5, a method for distributing charge to a hydrogen-rich carbon cycle oxygen blast furnace, comprising preparing a corresponding amount of ore according to the corresponding blast furnace specifications, and setting different distribution angles according to the corresponding blast furnace specifications. The specific distribution steps are as follows: S1: mixing high-basicity sintering material, scrap steel and coke into mixed material 1, mixing acidic pellets and vanadium-titanium pellets into mixed material 2, and feeding the mixed materials into the furnace through a distribution device in sequence; S2: Use the distribution device to distribute the mixed material in the furnace at a distribution angle of 28-40° for 4-6 turns; S3: After Mix 1 has been spread over 4-6 circles, Mix 2 is spread over the furnace at a spreading angle of 25-35° for 3-5 circles; S4: After Mix 2 has been spread for 3-5 turns, spread Mix 2 in the furnace at a spreading angle of 23-30° for 3-4 turns until the whole batch is spread.

[0012] According to the 2500m³ hydrogen-rich carbon-cycle oxygen blast furnace and the 430m³ hydrogen-rich carbon-cycle oxygen blast furnace, the charging angle of the 2500m³ hydrogen-rich carbon-cycle oxygen blast furnace is 25-40°, and the charging angle of the 430m³ hydrogen-rich carbon-cycle oxygen blast furnace is 23-30°, and the charging angles of different charges are set within this charging angle range.

[0013] Scheme 6, which is the preferred scheme of scheme 5, adopts the distribution method of high-basicity sintering material, scrap steel and coke in the outer circle, acidic pellets and vanadium-titanium pellets in the inner circle, and distributes high-basicity sintering material, scrap steel and coke in a ring shape near the furnace wall, and distributes acidic pellets and vanadium-titanium pellets in a ring shape near the center. Taking advantage of the relatively weak air flow at the edge of the upper part of the blast furnace and the strong air flow in the center, the deterioration of air permeability caused by rapid reduction and pulverization of sintering can be avoided in the upper part of the blast furnace, reducing the impact on the flow of blast furnace. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below through specific embodiments: Embodiment 1 A charge structure for a hydrogen-rich carbon circulating oxygen blast furnace, comprising: During the normal production stage of the blast furnace, the proportion of the ore is set to: 20-40% high-basicity sintering material, 5-10% scrap steel, 1-1.5% coke, 60-80% acidic pellets and 5-20% vanadium-titanium pellets. The particle size of the high-basicity sintering material is 5-25mm, the particle size of the acidic pellets is 5-20mm, the mass ratio of CaO to SiO2 in the high-basicity sintering material is controlled between 2.2-2.6, the MgO content in the high-basicity sintering material is controlled at 2-2.5%, and the FeO content is controlled at more than 9.5%; High basicity sintering material is a raw material used in the sintering process. It is characterized by high basicity, which is usually measured by the ratio of CaO / SiO2. This raw material can improve the quality of sintered ore during sintering, such as improving the strength and reducibility of sintered ore, and is beneficial to the optimization of slag performance in the blast furnace ironmaking process.

[0015] In the shutdown preparation stage before blast furnace maintenance, the addition amount of high basicity sintering material is adjusted to 20-30%, and the addition amount of acidic pellets is adjusted to 70-80%; During the start-up and recovery phase after the blast furnace overhaul, add 20% of sintering material and 80% of pelletized ore, make slight adjustments or no adjustments to other ore additions, and gradually increase the air volume into the furnace to the normal air volume corresponding to the blast furnace scale. Adjust the ore according to the air volume into the furnace. The specific method is as follows: When the air volume into the furnace is restored to 70% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke is increased to 30%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 70%; When the air volume into the furnace is restored to 80% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke is increased to 35%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 65%; When the air volume entering the furnace is restored to 90% of the normal air volume, the addition amount of high-basicity sintering material, scrap steel and coke will be increased to 40%, and the addition amount of acidic pellets will be reduced to 60%.

[0016] During the preparation stage before blast furnace shutdown and the recovery stage after blast furnace startup, instruments are used to detect the content of CO+H2 in the reducing gas in the furnace. According to the detected CO+H2 content, corresponding nitrogen is added to the circulating gas to control the content of CO+H2 in the reducing gas in the furnace to ≤50%.

[0017] The specific implementation of this embodiment is as follows: 1. In a 2500m³ hydrogen-rich carbon cycle oxygen blast furnace, the charge ratio can be set to: 28% high-basicity sintering material, 5% scrap steel, 1% coke, 60% acidic pellets and 6% vanadium-titanium pellets. The high-basicity sintering material used includes: 52.5% TFe, 6.18% SiO2, 14.27% CaO, 2.5% MgO, 1.19% Al2O3, 0.072% S, 0.49% TMn, 0.24% TiO2, 0.06% Zn. The mass ratio of CaO to SiO2 in the high-basicity sintering material is 2.31; In the shutdown preparation stage before blast furnace overhaul, the addition amount of high basicity sintering material is adjusted from 28% to 30%, and the addition amount of acidic pellets and vanadium-titanium pellets is adjusted from 60% to 70%; in the startup recovery stage after blast furnace overhaul, the addition amount of high basicity sintering material, scrap steel and coke is set to 20%, and the addition amount of acidic pellets and vanadium-titanium pellets is set to 80%, and the air volume into the furnace is gradually increased to 170,000 m³ / h. The ore is adjusted according to the air volume into the furnace, specifically: When the air volume into the furnace is restored to 119±0.3 thousand m³ / h, the addition amount of high basicity sintering material is increased to 30%, and the addition amount of acidic pellets and vanadium-titanium pellets is reduced to 70%; When the air volume into the furnace is restored to 136±0.3 thousand m³ / h, the addition amount of high basicity sintering material is increased to 35%, and the addition amount of acidic pellets and vanadium-titanium pellets is reduced to 65%; When the air volume into the furnace is restored to 153±0.3 thousand m³ / h, the addition amount of high basicity sintering material is increased to 40%, and the addition amount of acidic pellets and vanadium-titanium pellets is reduced to 60%.

[0018] 2. In a 430m³ hydrogen-rich carbon circulating oxygen blast furnace, the charge ratio can be set to: 23% high-basicity sintering material, 5.8% scrap steel, 1.2% coke, 65% acidic pellets and 5% vanadium-titanium pellets. The high-basicity sintering material contains: 52.5% TFe, 6.18% SiO2, 14.27% CaO, 2.5% MgO, 1.19% Al2O3, 0.072% S, 0.49% TMn, 0.24% TiO2, 0.06% Zn. The mass ratio of CaO to SiO2 in the high-basicity sintering material is 2.31; In the shutdown preparation stage before blast furnace overhaul, the addition amount of high basicity sintering material, scrap steel and coke is adjusted to 30%, and the addition amount of acidic pellets and vanadium-titanium pellets is adjusted to 70%; in the startup recovery stage after blast furnace overhaul, the addition amount of high basicity sintering material, scrap steel and coke is set to 20%, and the addition amount of acidic pellets and vanadium-titanium pellets is set to 80%, and the air volume into the furnace is gradually increased to 40,000 m³ / h. The ore is adjusted according to the air volume into the furnace, specifically: When the air volume into the furnace is restored to 28,000±3,000 m³ / h, the addition of high-basicity sintering material, scrap steel and coke is increased to 30%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 70%; When the air volume into the furnace is restored to 32,000±3,000 m³ / h, the addition of high-basicity sintering material, scrap steel and coke is increased to 35%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 65%; When the air volume into the furnace is restored to 36,000±3,000 m³ / h, the addition of high-basicity sintering material, scrap steel and coke will be increased to 40%, and the addition of acidic pellets and vanadium-titanium pellets will be reduced to 60%.

[0019] Embodiment 2 A method for distributing materials to a hydrogen-rich carbon cycle oxygen blast furnace includes preparing a corresponding amount of ore according to the corresponding blast furnace specifications, and setting different distribution angles according to the corresponding blast furnace specifications. The specific distribution steps are as follows: S1: mixing high-basicity sintering material, scrap steel and coke into mixed material 1, mixing acidic pellets and vanadium-titanium pellets into mixed material 2, and feeding the mixed materials into the furnace through a distribution device in sequence; S2: Use the distribution device to distribute the mixed material in the furnace at a distribution angle of 28-40° for 4-6 turns; S3: After Mix 1 has been spread over 4-6 circles, Mix 2 is spread over the furnace at a spreading angle of 25-35° for 3-5 circles; S4: After Mix 2 has been spread for 3-5 turns, spread Mix 2 in the furnace at a spreading angle of 23-30° for 3-4 turns until the whole batch is spread.

[0020] The high-alkalinity sintering material, scrap steel and coke are placed in the outer circle, and the acidic pellets and vanadium-titanium pellets are placed in the inner circle. The high-alkalinity sintering material, scrap steel and coke are placed in a ring shape near the furnace wall, and the acidic pellets and vanadium-titanium pellets are placed in a ring shape near the center.

[0021] The specific implementation of this embodiment is as follows: When carrying out the charging process for a 2500m³ hydrogen-rich carbon circulating oxygen blast furnace, firstly, mix 1 and mix 2 are sequentially fed into the furnace through the charging device, and then mix 1 is distributed in the furnace at a distribution angle of 35-40° for 6 turns. When mix 1 has been distributed for 6 turns, mix 2 is distributed in the furnace at a distribution angle of 30-35° for 5 turns. When mix 2 has been distributed for 5 turns, mix 2 is again distributed in the furnace at a distribution angle of 28-30° for 4 turns.

[0022] When carrying out the charging process for a 430m³ hydrogen-rich carbon circulating oxygen blast furnace, firstly, mix 1 and mix 2 are sequentially fed into the furnace through the charging device, and then mix 1 is distributed in the furnace at a distribution angle of 27-30° for 4 turns; when mix 1 has been distributed for 4 turns, mix 2 is distributed in the furnace at a distribution angle of 25-27° for 3 turns; when mix 2 has been distributed for 3 turns, mix 2 is again distributed in the furnace at a distribution angle of 23-25° for 3 turns.

[0023] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A charge structure for a hydrogen-rich carbon circulating oxygen blast furnace, characterized in that: include: During the normal production stage of the blast furnace, the proportion of the ore is set as follows: 20-40% high-basicity sintering material, 5-10% scrap steel, 1-1.5% coke, 60-80% acidic pellets and 5-20% vanadium-titanium pellets; In the shutdown preparation stage before blast furnace maintenance, the addition amount of high basicity sintering material is adjusted to 20-30%, and the addition amount of acidic pellets is adjusted to 70-80%; During the startup and recovery phase after the blast furnace overhaul, the addition amount of high-alkalinity sintering material, scrap steel and coke is set to 20%, and the addition amount of acidic pellets and vanadium-titanium pellets is set to 80%. The air volume entering the furnace is gradually increased to the normal air volume corresponding to the scale of the blast furnace, and the ore is adjusted according to the air volume entering the furnace.

2. The charge structure of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: The mass ratio of CaO to SiO2 in the high basicity sintering material is controlled between 2.2-2.6, the MgO content in the high basicity sintering material is controlled between 2-2.5%, and the FeO content is controlled above 9.5%.

3. The charge structure of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: During the preparation stage before blast furnace shutdown and the recovery stage after blast furnace startup, instruments are used to detect the content of CO+H2 in the reducing gas in the furnace. According to the detected CO+H2 content, corresponding nitrogen is added to the circulating gas to control the content of CO+H2 in the reducing gas in the furnace to ≤50%.

4. The charge structure of a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: The specific method of adjusting the proportion of ore materials according to the air volume entering the furnace is: When the air volume into the furnace is restored to 70% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke is increased to 30%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 70%; When the air volume into the furnace is restored to 80% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke is increased to 35%, and the addition of acidic pellets and vanadium-titanium pellets is reduced to 65%; When the air volume entering the furnace is restored to 90% of the normal air volume, the addition of high-basicity sintering material, scrap steel, and coke will be increased to 40%, and the addition of acidic pellets and vanadium-titanium pellets will be reduced to 60%.

5. A method for distributing materials to a hydrogen-rich carbon circulating oxygen blast furnace, characterized in that: It includes preparing the corresponding amount of ore according to the corresponding blast furnace specifications, setting different feeding angles according to the corresponding blast furnace specifications, and the specific feeding steps are as follows: S1: mixing high-basicity sintering material, scrap steel and coke into mixed material 1, mixing acidic pellets and vanadium-titanium pellets into mixed material 2, and feeding the mixed materials into the furnace through a distribution device in sequence; S2: Use the distribution device to distribute the mixed material in the furnace at a distribution angle of 28-40° for 4-6 turns; S3: After Mix 1 has been spread over 4-6 circles, Mix 2 is spread over the furnace at a spreading angle of 25-35° for 3-5 circles; S4: After Mix 2 has been spread for 3-5 turns, Mix 2 is spread in the furnace again at a spreading angle of 23-30° for 3-4 turns until the whole batch is spread.

6. A method for distributing materials to a hydrogen-rich carbon cycle oxygen blast furnace according to claim 5, characterized in that: High-basicity sintering materials, scrap steel and coke are placed near the furnace wall, and acidic pellets and vanadium-titanium pellets are placed near the center of the furnace throat. The placed materials are all in a ring shape.