Method for distributing small-particle ore in blast furnace

Abstract

The invention relates to a distribution method for small-particle ores in a blast furnace, belongs to the technical field of blast furnace ironmaking, and aims to solve the problems of poor air permeability of a material layer, rise of pressure difference in the furnace and the like in the blast furnace smelting process of the existing small-particle ores. Comprising the steps that existing sintering return mine and blast furnace return mine are subjected to grading treatment, small-particle ore with the particle size of 3-5 mm is screened and then independently stored in a small-particle ore bin, and large-particle furnace charge is kept consistent with actual production without adjustment; the small-particle ores and the large-particle furnace charges are distributed according to a preset distribution sequence and a distribution matrix by controlling an independent particle ore bin; according to the grade of the effective volume of the blast furnace, the initial distribution chute angle of the small-particle ore is adjusted, and the small-particle ore is distributed to the blast furnace throat close to the center area. By optimizing the distribution sequence of the small-particle ores in the blast furnace, the chute angle and the area distributed into the furnace throat, the air permeability of a material layer is improved, the pressure difference in the furnace is reduced, and normal smelting of the small-particle ores in the blast furnace is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace ironmaking, and in particular to a method for distributing small particle ore in a blast furnace. Background Art

[0002] The blast furnace is the primary process for ironmaking in my country, currently accounting for over 90% of my country's total iron production. A typical blast furnace charge typically consists of 70-75% sintered ore, 10-20% pellets, and 10-20% lump ore. Blast furnaces have a high demand for sintered ore, and the sintering process is one of the primary sources of pre-iron pollutant emissions.

[0003] During the blast furnace smelting process, to ensure good air permeability within the blast furnace, the particle size of the incoming charge is generally required to be greater than 5mm. Therefore, before loading the blast furnace, the charge is screened again, and the portion with a particle size less than 5mm is returned to the sintering process. This portion, known as blast furnace return ore, accounts for approximately 10-15%. At the same time, the sintering process also produces a certain amount of return ore with a particle size less than 5mm, accounting for approximately 20-30%. Therefore, the total return ore volume of small-particle return ore (particle size <5mm) is approximately 30-45%. This large amount of return ore is continuously recycled into the sintering process, resulting in increased energy consumption in the sintering process and high emissions of sintering flue gas pollutants. In addition, during the actual blast furnace smelting process, due to the impact and wear during the material transportation process, the loss of screening equipment and the screening efficiency, a certain proportion of ores with a particle size of <5mm enter the blast furnace during the actual blast furnace smelting process. These ores with a particle size of <5mm enter the blast furnace together with the charge, which not only causes a large change in the particle size distribution of the charge entering the furnace, but also because the segregation phenomenon of small-particle charge is more serious than that of large-particle charge, it will cause the average particle size of the local charge to decrease significantly, the porosity of the material layer to decrease, and seriously affect the permeability of the material layer, resulting in an increase in the local pressure difference in the blast furnace, resulting in a decrease in coal gas utilization, an increase in direct reduction, and an increase in fuel ratio and carbon emissions, which seriously affects the smooth operation of the blast furnace.

[0004] At present, the research on blast furnace charge distribution mainly focuses on the adjustment of charge distribution equipment or the movement law of charge. There is little research on the impact of changes in charge particle size inside the blast furnace on the gas flow distribution and pressure drop in the furnace. Mechanical forced screening alone cannot fundamentally solve the problem of the impact of powder in the charge on blast furnace smelting. On the contrary, excessive screening will increase the overall smelting cost, which is not conducive to reducing the energy consumption and carbon emissions of blast furnace smelting. Summary of the Invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide a method for distributing small-particle ore in a blast furnace, so as to solve the problems of poor air permeability of the material layer and increased pressure difference in the furnace caused by the existing method of distributing small-particle ore in the blast furnace during the blast furnace smelting process.

[0006] The purpose of the present invention is mainly achieved through the following technical solutions:

[0007] The present invention provides a method for distributing small-sized ore particles in a blast furnace, comprising the following steps:

[0008] S1: Classify the sintering return ore and blast furnace return ore, and only screen the small particles with a particle size of 3-5 mm and store them separately in the small particle ore silo;

[0009] S2: By controlling the separate pellet silo, small-sized ore and large-sized furnace charge are distributed according to the predetermined distribution sequence and distribution matrix;

[0010] S3: According to the level of the effective volume of the blast furnace, the initial distribution chute angle of the small particle ore is adjusted to distribute the small particle ore to the center area of ​​the blast furnace throat.

[0011] Furthermore, in step S1, the small particle ore is one or more of sintered ore, lump ore or pellet ore.

[0012] Furthermore, in step S1, the large particle charge includes coke dicing with a particle size of 10 to 20 mm, lump ore with a particle size of 10 to 40 mm, pellet ore with a particle size of 10 to 20 mm and sintered ore with a particle size of 5 to 40 mm.

[0013] Furthermore, in step S2, the order of distributing the materials is: small particle ore - sintered ore - coke dicing - lump ore - pellet ore.

[0014] Furthermore, in step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, including: when the blast furnace effective volume is 2000m 3 Below the grade, the initial distribution chute angle of small particle ore is 24-30°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.21-0.43R, where R is the blast furnace throat radius, in m.

[0015] Furthermore, in step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 2000m 3 The initial distribution chute angle of small particle ore is 22-28°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.2-0.39R, where R is the blast furnace throat radius, in m.

[0016] Furthermore, in step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 3000m3 The initial distribution chute angle of small particle ore is 20-25°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.2-0.4R, where R is the blast furnace throat radius, in m.

[0017] Furthermore, in step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 4000m 3 The initial distribution chute angle of small particle ore is 14-19°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.19-0.38R, where R is the blast furnace throat radius, in m.

[0018] Furthermore, in step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 4000m 3 Above the grade, the initial distribution chute angle of small particle ore is 12-18°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.20-0.39R, where R is the blast furnace throat radius, in meters.

[0019] Furthermore, in step S3, the time for discharging the small-particle ore to the center area of ​​the blast furnace throat is 8 to 10 seconds.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0021] 1. The present invention optimizes the order of distributing small-particle ore in the blast furnace and the area where it is distributed into the furnace throat, thereby improving the permeability of the material layer and reducing the pressure difference in the furnace, so that small-particle ore that originally needed to be returned to the sintering process can be smelted normally in the blast furnace.

[0022] 2. The present invention optimizes the angle of the distribution chute of small-particle ore and the position of its placement into the furnace throat, thereby optimizing the pressure drop and permeability of the blast furnace material layer, improving the gas flow distribution in the upper part of the blast furnace, increasing the gas utilization rate, and ensuring the stable and smooth operation of the blast furnace.

[0023] 3. The distribution method of the present invention can ensure the normal use of small-particle ore in the blast furnace, reduce the amount of ore returned to the blast furnace trough and sintering, indirectly reduce the total amount of sintered ore required, reduce the cost of sintered ore, and further reduce the smelting cost of ore fed into the blast furnace.

[0024] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0026] Figure 1 This is a schematic diagram of the position of small-particle ore in a material tank according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the distribution of small particle ore in the throat area of ​​a blast furnace according to Example 1 of the present invention;

[0028] Figure 3 This is a comparison diagram of the distribution of small particle ore in the blast furnace throat area of ​​Example 1 of the present invention and Comparative Example 2;

[0029] Figure 4 1 is a radial pressure drop distribution diagram at the throat position of Example 1, Comparative Example 1, and Comparative Example 2 of the present invention.

[0030] Figure numerals: 1- small particle ore; 2- large particle charge. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0032] The present invention provides a method for distributing small-sized ore particles in a blast furnace, comprising the following steps:

[0033] S1: Classify the sintering return ore and blast furnace return ore, and only screen the small particles with a particle size of 3-5 mm and store them separately in the small particle ore silo;

[0034] S2: By controlling the separate pellet silo, small-sized ore and large-sized furnace charge are distributed according to the predetermined distribution sequence and distribution matrix;

[0035] S3: According to the level of the effective volume of the blast furnace, adjust the initial distribution chute angle of the small particle ore and distribute the small particle ore to the center area near the blast furnace throat.

[0036] Blast furnaces account for over 85% of my country's ironmaking output, and will remain the primary process for ironmaking in the country for decades to come. To ensure the permeability of the charge bed within the blast furnace, the size of the incoming charge is generally required to be larger than 5mm. However, in recent years, with the continuous depletion of iron ore resources, various types of iron ore have shown a trend of degradation, and some small particles of ore have entered the blast furnace. This not only significantly changes the particle size distribution of the incoming charge, with a significant decrease in the average particle size, but also increases the charge's bulk density and reduces its porosity. This results in a decrease in the permeability of the charge bed and an increase in the pressure differential within the blast furnace, affecting the smooth operation of the blast furnace. In severe cases, this can cause accidents such as suspended charge. The present invention improves the permeability of the material layer and reduces the pressure difference in the furnace by optimizing and adjusting the distribution sequence of small-particle ores in the blast furnace, optimizing the angle of the distribution chute and the area of ​​distribution into the furnace throat, so that the small-particle ores that originally need to be returned to the sintering process can be smelted normally in the blast furnace, which can ensure the normal use of small-particle ores in the blast furnace, reduce the amount of ore returned under the blast furnace trough and during sintering, and indirectly reduce the total amount of sintered ore required, thereby reducing the cost of sintered ore and further reducing the smelting cost of ore entering the blast furnace.

[0037] Specifically, in the present invention, the small-particle ore is one or more of sintered ore, lump ore or pellet ore, with a particle size of 3 to 5 mm; the large-particle charge includes coke (10 to 20 mm), lump ore (10 to 40 mm), pellet ore (10 to 20 mm) and sintered ore (5 to 40 mm).

[0038] In step S1, the large particle charge remains consistent with actual production and is not adjusted.

[0039] In step S2, the distribution matrix is ​​to set the distribution chute angle and the number of rotations according to the different gears of the blast furnace; the small-sized ore is discharged to the feeding belt before the other particle size furnace materials, and the other particle size furnace materials are distributed according to the actual production distribution sequence and matrix of the blast furnace without adjustment; the remaining furnace materials are mixed and loaded into the upper part of the material tank, such as Figure 1 As shown, the order of distribution is: sintered ore - coke - lump ore - pelletized ore.

[0040] In step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the effective volume of the blast furnace to ensure that the small-particle ore is distributed to the center area of ​​the furnace throat, and the discharge time is 8 to 10 seconds.

[0041] When the effective volume of the blast furnace is 2000m 3 Below the grade, the initial distribution chute angle of small particle ore is 24-30 degrees, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.21-0.43R, where R is the blast furnace throat radius, in meters;

[0042] When the effective volume of the blast furnace is 2000m 3The initial distribution chute angle of small particle ore is 22-28 degrees, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.2-0.39R, where R is the blast furnace throat radius, in meters;

[0043] When the effective volume of the blast furnace is 3000m 3 The initial distribution chute angle of small particle ore is 20-25 degrees, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.2-0.4R, where R is the blast furnace throat radius, unit is m;

[0044] When the effective volume of the blast furnace is 4000m 3 The initial distribution chute angle of small particle ore is 14-19 degrees, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.19-0.38R, where R is the blast furnace throat radius, unit is m;

[0045] When the effective volume of the blast furnace is 4000m 3 Above the grade, the initial distribution chute angle of small particle ore is 12-18°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.20-0.39R, where R is the blast furnace throat radius, in meters.

[0046] The present invention optimizes and adjusts the distribution sequence, distribution chute angle and distribution area of ​​small-particle ore in the blast furnace throat, effectively controls the radial distribution of small-particle ore in the furnace throat area, and improves the radial permeability of the charge in the furnace throat area without affecting the gas flow distribution in the central area of ​​the furnace throat, making the gas flow distribution in the radial area more reasonable, which is beneficial to the stable and smooth operation of the blast furnace, reducing the comprehensive cost of blast furnace ironmaking and the energy consumption of the sintering process, and reducing the emission of sintering pollutants. The present invention has the characteristics of simple process scheme, strong operability, and significant energy-saving and emission reduction effects.

[0047] Example 1

[0048] In this embodiment, the effective volume of the blast furnace is 3200m 3 The furnace throat diameter is 9m, and the charge includes 3t of coke dicing, 6.3t of lump ore, 13t of pellets, and 64.6t of sintered ore. The amount of small-particle ore is 5.4t, with a particle size of 3-5mm.

[0049] The specific steps are as follows:

[0050] S1: Classify the existing sintering return ore and blast furnace return ore, screen the small particles of 3-5mm and store them separately in the small particle ore silo, and keep the large particle charge consistent with the actual production without adjustment;

[0051] S2: By controlling the separate pellet silo, small pellets are discharged to the feeding belt before other particle size materials, so as to ensure that the small pellets are located at the bottom of the tank after entering the tank, and the rest of the materials are mixed and loaded into the upper part of the tank, such as Figure 1 As shown, the order of material distribution is: sintered ore - coke - lump ore - pellets;

[0052] S3: Start charging. Open the throttle valve and charge according to the predetermined charging matrix. Adjust the initial charging chute angle to 25° and rotate once. Charge the small-sized ore to the center of the blast furnace throat at a distance of 0.9 to 1.8 m (i.e., 0.2 to 0.4 R). Charges of other particle sizes are charged according to the actual production charging matrix of the blast furnace without adjustment.

[0053] The distribution matrix of other particle size charges is:

[0054] gear 1 2 3 4 5 Chute angle / ° 42 40 37.5 35 32.5 Number of rotations 3 3 3 2 2

[0055] In this embodiment, the pressure drop data in the furnace is:

[0056] 0.0~0.2R area: 392Pa / m, 0.2~0.4R area: 725Pa / m, 0.4~0.6R area: 1666Pa / m, 0.6~0.8R area: 2631Pa / m, 0.8~1.0R area: 3018Pa / m.

[0057] Example 2

[0058] In this embodiment, the effective volume of the blast furnace is 3200m 3 The furnace throat diameter is 9m, and the charge includes 3t of coke dicing, 6.3t of lump ore, 13t of pellets, and 64.6t of sintered ore. The amount of small-particle ore is 5.4t, with a particle size of 3-5mm.

[0059] The specific steps are as follows:

[0060] S1: Classify the existing sintering return ore and blast furnace return ore, screen the small particles of 3-5mm and store them separately in the small particle ore silo, and keep the large particle charge consistent with the actual production without adjustment;

[0061] S2: By controlling the separate pellet silo, small pellets are discharged to the feeding belt before other particle size materials, so as to ensure that the small pellets are located at the bottom of the tank after entering the tank, and the rest of the materials are mixed and loaded into the upper part of the tank, such as Figure 1 As shown, the order of material distribution is: sintered ore - coke - lump ore - pellets;

[0062] S3: Start charging. Open the throttle valve and charge according to the predetermined charging matrix. Adjust the initial charging chute angle to 20° and rotate once. Charge the small-sized ore to the center of the blast furnace throat at a distance of 0.9 to 1.8 m (i.e., 0.2 to 0.4 R). Charges of other particle sizes are charged according to the actual production charging matrix of the blast furnace without adjustment.

[0063] The distribution matrix of charge materials of other particle sizes is the same as that of Example 1.

[0064] In this embodiment, the pressure drop data in the furnace is:

[0065] 0.0~0.2R area: 516Pa / m, 0.2~0.4R area: 768Pa / m, 0.4~0.6R area: 1581Pa / m, 0.6~0.8R area: 2496Pa / m, 0.8~1.0R area: 2652Pa / m.

[0066] Example 3

[0067] In this embodiment, the effective volume of the blast furnace is 3200m 3 The furnace throat diameter is 9m, and the charge includes 3t of coke dicing, 6.3t of lump ore, 13t of pellets, and 64.6t of sintered ore. The amount of small-particle ore is 5.4t, with a particle size of 3-5mm.

[0068] The specific steps are as follows:

[0069] S1: Classify the existing sintering return ore and blast furnace return ore, screen the small particles of 3-5mm and store them separately in the small particle ore silo, and keep the large particle charge consistent with the actual production without adjustment;

[0070] S2: By controlling the separate pellet silo, small pellets are discharged to the feeding belt before other particle size materials, so as to ensure that the small pellets are located at the bottom of the tank after entering the tank, and the rest of the materials are mixed and loaded into the upper part of the tank, such as Figure 1 As shown, the order of material distribution is: sintered ore - coke - lump ore - pellets;

[0071] S3: Start charging. Open the throttle valve and charge according to the predetermined charging matrix. Adjust the initial charging chute angle to 23° and rotate once. Charge the small-sized ore to the center of the blast furnace throat at a distance of 0.9 to 1.8 m (i.e., 0.2 to 0.4 R). Charges of other particle sizes are charged according to the actual production charging matrix of the blast furnace without adjustment.

[0072] The distribution matrix of charge materials of other particle sizes is the same as that of Example 1.

[0073] In this embodiment, the pressure drop data in the furnace is:

[0074] 0.0~0.2R area: 452Pa / m, 0.2~0.4R area: 744Pa / m, 0.4~0.6R area: 1602Pa / m, 0.6~0.8R area: 2653Pa / m, 0.8~1.0R area: 2880Pa / m.

[0075] Example 4

[0076] In this embodiment, the effective volume of the blast furnace is 2500m 3 The furnace throat diameter is 8.1m, and the charge includes 1.5t of diced coke, 6.0t of lump ore, 11.3t of pellets, and 56.2t of sintered ore. The amount of small-particle ore is 4.5t, with a particle size of 3-5mm.

[0077] The specific steps are as follows:

[0078] S1: Classify the existing sintering return ore and blast furnace return ore, screen the small particles of 3-5mm and store them separately in the small particle ore silo, and keep the large particle charge consistent with the actual production without adjustment;

[0079] S2: By controlling the separate pellet silo, small pellets are discharged to the feeding belt before other particle size materials, so as to ensure that the small pellets are located at the bottom of the tank after entering the tank, and the rest of the materials are mixed and loaded into the upper part of the tank, such as Figure 1 As shown, the order of material distribution is: sintered ore - coke - lump ore - pellets;

[0080] S3: Start charging. Open the throttle valve and charge according to the predetermined charging matrix. Adjust the initial charging chute angle to 25° and rotate once. Charge the small-sized ore to the center of the blast furnace throat at a distance of 0.81 to 1.58 m (i.e., 0.2 to 0.39 R). Charges of other particle sizes are charged according to the actual production charging matrix of the blast furnace without adjustment.

[0081] The distribution matrix of other particle size charges is:

[0082] gear 1 2 3 4 5 Chute angle / ° 40 38.5 37 35 33 Number of rotations 1 3 2 3 3

[0083] In this embodiment, the pressure drop data in the furnace is:

[0084] 0.0~0.2R area: 311Pa / m, 0.2~0.4R area: 1052Pa / m, 0.4~0.6R area: 1915Pa / m, 0.6~0.8R area: 2625Pa / m, 0.8~1.0R area: 2810Pa / m.

[0085] Example 5

[0086] In this embodiment, the effective volume of the blast furnace is 4070m 3The furnace throat diameter is 9.6m, and the charge includes 2.4t of coke dicing, 9.6t of lump ore, 18t of pellets, and 90t of sintered ore. The amount of small-particle ore is 6.8t, with a particle size of 3-5mm.

[0087] The specific steps are as follows:

[0088] S1: Classify the existing sintering return ore and blast furnace return ore, screen the small particles of 3-5mm and store them separately in the small particle ore silo, and keep the large particle charge consistent with the actual production without adjustment;

[0089] S2: By controlling the separate pellet silo, small pellets are discharged to the feeding belt before other particle size materials, so as to ensure that the small pellets are located at the bottom of the tank after entering the tank, and the rest of the materials are mixed and loaded into the upper part of the tank, such as Figure 1 As shown, the order of material distribution is: sintered ore - coke - lump ore - pellets;

[0090] S3: Start charging. Open the throttle valve and charge according to the predetermined charging matrix. Adjust the initial charging chute angle to 15° and rotate once. Charge the small-sized ore to the center of the blast furnace throat at a distance of 0.91 to 1.82 m (i.e., 0.19 to 0.38 R). Charges of other particle sizes are charged according to the actual production charging matrix of the blast furnace without adjustment.

[0091] The distribution matrix of other particle size charges is:

[0092] gear 1 2 3 4 5 6 7 Chute angle / ° 40.5 38.5 36.5 34.5 32.5 30.5 28.5 Number of rotations 3 3 3 2 2 2 3

[0093] In this embodiment, the pressure drop data in the furnace is:

[0094] 0.0~0.2R area: 314Pa / m, 0.2~0.4R area: 1052Pa / m, 0.4~0.6R area: 1899Pa / m, 0.6~0.8R area: 2389Pa / m, 0.8~1.0R area: 2937Pa / m.

[0095] Example 6

[0096] In this embodiment, the effective volume of the blast furnace is 5500m 3 The furnace throat diameter is 11.2m, and the charge includes 6t of diced coke, 14t of lump ore, 34t of pellets, and 132t of sintered ore. The amount of small-particle ore is 8.4t, with a particle size of 3-5mm.

[0097] The specific steps are as follows:

[0098] S1: Classify the existing sintering return ore and blast furnace return ore, screen the small particles of 3-5mm and store them separately in the small particle ore silo, and keep the large particle charge consistent with the actual production without adjustment;

[0099] S2: By controlling the separate pellet silo, small pellets are discharged to the feeding belt before other particle size materials, so as to ensure that the small pellets are located at the bottom of the tank after entering the tank, and the rest of the materials are mixed and loaded into the upper part of the tank, such as Figure 1 As shown, the order of material distribution is: sintered ore - coke - lump ore - pellets;

[0100] S3: Start charging. Open the throttle valve and charge according to the predetermined charging matrix. Adjust the initial charging chute angle to 16° and rotate once. Charge the small-sized ore to the center of the blast furnace throat at a distance of 1.12 to 2.18 m (i.e., 0.2 to 0.39 R). Charges of other particle sizes are charged according to the actual production charging matrix of the blast furnace without adjustment.

[0101] The distribution matrix of other particle size charges is:

[0102]

[0103] In this embodiment, the pressure drop data in the furnace is:

[0104] 0.0~0.2R area: 184Pa / m, 0.2~0.4R area: 1155Pa / m, 0.4~0.6R area: 1861Pa / m, 0.6~0.8R area: 2718Pa / m, 0.8~1.0R area: 2572Pa / m.

[0105] Example 7

[0106] In this embodiment, the effective volume of the blast furnace is 1800m 3 The furnace throat diameter is 7.5m, and the charge includes 1t of coke dicing, 4t of lump ore, 5t of pellets, and 40t of sintered ore. The amount of small-particle ore is 2.5t, with a particle size of 3-5mm.

[0107] The specific steps are as follows:

[0108] S1: Classify the existing sintering return ore and blast furnace return ore, screen the small particles of 3-5mm and store them separately in the small particle ore silo, and keep the large particle charge consistent with the actual production without adjustment;

[0109] S2: By controlling the separate pellet silo, small pellets are discharged to the feeding belt before other particle size materials, so as to ensure that the small pellets are located at the bottom of the tank after entering the tank, and the rest of the materials are mixed and loaded into the upper part of the tank, such as Figure 1 As shown, the order of material distribution is: sintered ore - coke - lump ore - pellets;

[0110] S3: Start charging. Open the throttle valve and charge according to the predetermined charging matrix. Adjust the initial charging chute angle to 26° and rotate once. Charge the small-sized ore to the center of the blast furnace throat at a distance of 0.79 to 1.61 m (i.e., 0.21 to 0.43 R). Charges of other particle sizes are charged according to the actual production charging matrix of the blast furnace without adjustment.

[0111] The distribution matrix of other particle size charges is:

[0112] gear 1 2 3 4 Chute angle / ° 41 39 36.5 34 Number of rotations 2 3 3 2

[0113] In this embodiment, the pressure drop data in the furnace is:

[0114] 0.0~0.2R area: 285Pa / m, 0.2~0.4R area: 1045Pa / m, 0.4~0.6R area: 1663Pa / m, 0.6~0.8R area: 2473Pa / m, 0.8~1.0R area: 2637Pa / m.

[0115] Comparative Example 1

[0116] In this comparative example, the blast furnace charging, distribution sequence, and distribution matrix remain consistent with those in Example 1, and only the distribution chute angle of the small-particle ore is changed.

[0117] The specific steps are as follows:

[0118] S1: Repeat steps S1 and S2 in Example 1, and keep the distribution of the charge in the hopper as follows Figure 1 shown.

[0119] S2: When distributing the material, the angle of the distributing chute is no longer adjusted. At this time, the chute angle of the small-particle ore is 42°, and it mainly falls into the area 3.6 to 4.5 m (i.e. 0.8 to 1.0 R) from the edge of the furnace throat.

[0120] In this comparative example, the pressure drop data in the furnace is:

[0121] 0.0~0.2R area: 62Pa / m, 0.2~0.4R area: 1055Pa / m, 0.4~0.6R area: 2911Pa / m, 0.6~0.8R area: 5121Pa / m, 0.8~1.0R area: 7018Pa / m.

[0122] Comparative Example 2

[0123] In this comparative example, the effective volume of the blast furnace is 3200m 3 The furnace throat diameter is 9m, and the charge includes 3t of coke dicing, 6.3t of lump ore, 13t of pellets, and 64.6t of sintered ore. The amount of small-particle ore is 5.4t, with a particle size of 3-5mm.

[0124] The specific steps are as follows:

[0125] S1: The existing sintered ore and blast furnace ore are graded, and the small particles with a particle size of 3 to 5 mm are screened and then mixed with the sintered ore.

[0126] S2: Load the charge into the material tank in the order of coke, lump ore, pellet ore and sintered ore, and distribute the charge to the throat material surface in sequence according to the same distribution matrix as Example 1, without adjusting the chute angle.

[0127] In this comparative example, the pressure drop data in the furnace is:

[0128] 0.0~0.2R area: 853Pa / m, 0.2~0.4R area: 1967Pa / m, 0.4~0.6R area: 5810Pa / m, 0.6~0.8R area: 3696Pa / M, 0.8~1.0R area: 3882Pa / m.

[0129] Figure 4 The following is a comparison of the radial pressure drop distribution in the furnace throat for Example 1, Comparative Example 1, and Comparative Example 2. It can be seen that when small-particle sintered ore is placed near the center of the furnace throat (0.2-0.4R) in Example 1, the pressure drop in the furnace throat region is significantly improved compared to when small-particle sintered ore is placed in the 0.8-1.0R region at the edge of the furnace throat (Comparative Example 1) and when a mixture of small-particle ore is added to the blast furnace (Comparative Example 2). The improvement in pressure drop is particularly significant in the 0.4-1.0R region, indicating that the overall permeability of the material layer in this region has improved, facilitating stable and smooth operation of the blast furnace.

Claims

1. A method for distributing small-sized ore particles in a blast furnace, characterized in that: The following steps are involved: S1: Classify the sintering return ore and blast furnace return ore, and only screen the small particles with a particle size of 3-5 mm and store them separately in the small particle ore silo; S2: By controlling the separate pellet silo, small-sized ore and large-sized furnace charge are distributed according to the predetermined distribution sequence and distribution matrix; S3: According to the level of the effective volume of the blast furnace, adjust the initial distribution chute angle of the small particle ore and distribute the small particle ore to the center area near the blast furnace throat.

2. The material distributing method according to claim 1, characterized in that: In step S1, the small particle ore is one or more of sintered ore, lump ore or pellet ore.

3. The material distributing method according to claim 2, characterized in that: In step S1, the large particle charge includes coke dicing with a particle size of 10 to 20 mm, lump ore with a particle size of 10 to 40 mm, pellet ore with a particle size of 10 to 20 mm and sintered ore with a particle size of 5 to 40 mm.

4. The material distributing method according to claim 3, characterized in that: In step S2, the order of distributing the materials is: small particle ore - sintered ore - coke dicing - lump ore - pellet ore.

5. The material distributing method according to claim 4, characterized in that: In step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, including: when the blast furnace effective volume is 2000m 3 Below the grade, the initial distribution chute angle of small particle ore is 24-30°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.21-0.43R, where R is the blast furnace throat radius, in m.

6. The material distributing method according to claim 4, characterized in that: In step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 2000m 3 The initial distribution chute angle of small particle ore is 22-28°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.2-0.39R, where R is the blast furnace throat radius, in m.

7. The material distributing method according to claim 4, characterized in that: In step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 3000m 3 The initial distribution chute angle of small particle ore is 20-25°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.2-0.4R, where R is the blast furnace throat radius, in m.

8. The material distributing method according to claim 4, characterized in that: In step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 4000m 3 The initial distribution chute angle of small particle ore is 14-19°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.19-0.38R, where R is the blast furnace throat radius, in m.

9. The material distributing method according to claim 4, characterized in that: In step S3, the initial distribution chute angle of the small-particle ore is adjusted according to the level of the blast furnace effective volume, and the small-particle ore is distributed to the center area of ​​the blast furnace throat, which also includes: when the blast furnace effective volume is 4000m 3 Above the grade, the initial distribution chute angle of small particle ore is 12-18°, ensuring that the small particle ore is distributed to the blast furnace throat near the center area 0.20-0.39R, where R is the blast furnace throat radius, in meters.

10. The material distributing method according to claim 1, wherein: In step S3, the time for discharging the small-particle ore to the center area of ​​the blast furnace throat is 8 to 10 seconds.

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