Method for prolonging service life of blast furnace cooling wall

Abstract

The invention relates to a method for prolonging the service life of a blast furnace cooling wall. A blast furnace structure is improved, and the length of a blast furnace tuyere is increased; adjusting the inclination angle of the blast-furnace tuyere small sleeve to reduce the included angle with the horizontal plane; the bosh angle is set to be less than 75 degrees; and the service life of the cooling wall of the blast furnace is greatly prolonged through overall coordination and cooperation by matching with the change of a material distribution mode in the furnace, the improvement of a pellet and natural lump ore adding area, the improvement of a coke adding area and the reasonable arrangement of zinc load.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace ironmaking, and in particular to a method for prolonging the service life of a blast furnace cooling wall. Background Art

[0002] The cooling wall is an important component of the blast furnace body. During the smelting process, it is in direct contact with the charge inside the blast furnace. It not only has to withstand the mechanical wear of the charge and gas flow, but also has to withstand the thermal stress damage caused by temperature changes. In actual production, the 6th, 7th and 8th cooling walls at the bosh waist of the blast furnace are easily damaged, especially the 6th cooling wall. Since the bosh waist is a high heat load area, the high-temperature coal gas generated in the circulation area before the tuyere is affected by the dead material pile in the center of the blast furnace, and the ablation effect on the bosh waist is very severe. After the blast furnace is put into production, the charge at the bosh waist flows downward and the coal gas flows upward. The relative movement of the two exerts a large friction force on the furnace wall. At the same time, this part of the cooling wall is generally close to the circulation area before the tuyere, which further increases the frequency of the cooling wall being burned. For some blast furnaces, the damage rate of this part of the cooling wall exceeds half within 1-3 months after the furnace is opened, and it can only be solved by replacing the bosh waist cooling wall. The frequent replacement of the bosh waist cooling wall not only affects production, but also causes a large amount of manpower and material resources to be invested. At the same time, it also increases the frequency of blast furnace overhaul to a certain extent. The overhaul of the blast furnace will cause the overall shutdown of the ironmaking workshop, thereby causing a significant drop in production efficiency.

[0003] China's invention patent publication CN116121477A discloses a system and method for extending the life of the cooling wall, which uses a "water plus nitrogen" curing method to cool and maintain the damaged 6-section copper cooling wall to achieve the effect of extending the life of the cooling wall. If the technical problem of burning of this part can be solved from the inside of the blast furnace, the frequent burning of the cooling wall in this part will be essentially reduced. Summary of the invention

[0004] The present invention is used to overcome the defects of the prior art and provides a method for extending the service life of the blast furnace cooling wall by optimizing the charging sequence, improving the blast furnace charging method, and structurally modifying the blast furnace, so as to solve the problems mentioned in the background technology.

[0005] To achieve the above object, the present invention adopts the following technical solution: A method for extending the service life of a blast furnace cooling stave, the method comprising: (1) Improve the blast furnace structure: extend the length of the blast furnace tuyere; adjust the inclination angle of the blast furnace tuyere sleeve to reduce the angle between it and the horizontal plane; and set the furnace bosh angle to less than 75°; (2) The charging arrangement in the furnace is as follows: at the horizontal section at the throat of the blast furnace, the circular area from the center of the circle (1.7-1.9) m of the horizontal section to the center of the circle is defined as the central area A1; the circular area from the center of the circle (3.5-3.8) m of the horizontal section to the center of the circle (1.7-1.9) m of the horizontal section is defined as the middle area A2; the circular area from the center of the circle (3.5-3.8) m of the horizontal section to the inner wall of the blast furnace throat is defined as the outer area A3; During the blast furnace charging process, 80-90wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the middle zone, 5-10wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the central zone, and 5-10wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the outer zone, and the remaining iron ore materials in the central zone, middle zone and outer zone are sintered ore.

[0006] The above method for extending the service life of the blast furnace cooling wall is to set the blast furnace tuyere length to 475~490mm and set the angle of the blast furnace tuyere sleeve to be within the range of -2~2° with the horizontal plane.

[0007] The above method for extending the service life of the blast furnace cooling wall is as follows: during the blast furnace charging process, the proportion of coke distributed in the central area to the total distributed coke is greater than 30wt%, and the remaining coke is distributed in the middle area and the outer area at a ratio of 1:1.1 to 1:1.8.

[0008] The above method for extending the service life of the blast furnace cooling wall is as follows: during the blast furnace charging process, after every 4 to 8 normal charging cycles, pure coke is charged to the central area A1 separately, and the total amount of pure coke charged separately is 2 to 4 wt% of the total amount of coke added.

[0009] In the above method for extending the service life of a blast furnace cooling wall, the iron ore material comprises 9-12wt% of pelletized ore, 18-22wt% of natural lump ore, and the remainder is sintered ore.

[0010] In the above method for extending the service life of a blast furnace cooling wall, the iron ore material is configured so that the zinc load of the blast furnace is 0.18-0.19 kg / t.

[0011] The above method for extending the service life of the blast furnace cooling wall is to set the blast furnace belly angle to be less than 75° and greater than 70°.

[0012] In the above method for extending the service life of a blast furnace cooling wall, the proportion of coke arranged in the central area to the total coke arranged is greater than 30wt% and less than 45wt%.

[0013] The above method for extending the service life of the blast furnace cooling wall is to set the blast furnace body angle to 80-85°.

[0014] The above method for extending the service life of the blast furnace cooling wall sets the overall structure and proportion of the blast furnace to: the ratio between the blast furnace waist diameter and the furnace hearth diameter is 1.11~1.26; the ratio between the furnace belly height and the furnace waist height is 1.51~1.72; the ratio between the furnace body height and the furnace waist height is 6.39~6.51; the ratio between the furnace waist diameter and the furnace throat diameter is 1.30~1.65. Beneficial effects of the present invention:

[0015] First, the present invention extends the length of the tuyere so that the airflow is more fully developed toward the center of the blast furnace; the angle of the tuyere sleeve is adjusted from the existing inclination of about 5° to an angle close to the horizontal, thereby effectively reducing the airflow flow vector in the vertical direction; and a relatively small furnace belly angle is further set to further increase the difficulty of the airflow flowing to the edge position; the above three aspects are coordinated to strengthen the development of the central airflow and avoid the excessive development of the edge airflow, thereby greatly reducing the wear caused by the contact between the blast furnace cooling wall and the airflow and materials from the perspective of blast furnace structure improvement. At the same time, more importantly, it prevents the temperature in the furnace at the cooling wall from being too high, thereby reducing the probability of burning of the cooling wall from the two dimensions of suppressing wear and controlling temperature, and also prevents the occurrence of a mutually reinforcing burning mechanism of the two dimensions of excessive development of the edge airflow and excessive temperature.

[0016] Second, the conventional method is to divide the blast furnace charging area into three areas: the central area, the middle area and the edge area (some areas are divided into two areas). However, the present invention does not simply limit the division method of the three areas, but specifically limits the three finely divided areas and the iron ore materials (i.e., metal materials) and coke materials in the three specific areas. By arranging the pellets and natural lump ore in the middle area, the advantages of this arrangement are: (1) the pellets and natural ore have good strength, less powder, and good permeability of the material layer, thereby improving the air flow intensity in the middle area and correspondingly suppressing the air flow intensity in the edge area; (2) the proportion of pellets and natural lump ore in the edge area is low, and the proportion of sintered ore is high. During the preparation of sintered ore, alkaline materials such as limestone are added, so that the binary alkalinity (i.e., the ratio of CaO to SiO2) of sintered ore is usually higher than that of pelletized ore and natural ore, thereby increasing the binary alkalinity of the edge area (especially the outermost ring of the furnace wall), thereby avoiding the formation of a low melting point at the outermost ring of the furnace wall (so that the material at the outermost ring of the furnace wall will not melt too early near the cooling wall near the furnace wall); (3) increase the proportion of coke in the central area and reduce the addition of coke in the other two areas, and at the same time, add coke to the central area through a periodic cycle of a specific frequency, so as to ensure that the central airflow is properly strengthened and the blast furnace fuel ratio does not rise too much. The above setting of a specific area and specific proportion of iron ore materials, combined with a specific area and specific proportion of coke and a specific addition method, strengthens the central airflow and avoids the premature formation of molten materials at the edge, thereby greatly reducing excessive wear and burning at the cooling wall.

[0017] Third, since the lower the zinc load, the lower the control of harmful elements can be pursued. In many existing blast furnace systems, the zinc load is set to less than 0.15kg / t, but this requires relatively strict strict limitation of each component in the iron ore material, which greatly increases the smelting cost. The present invention, through the transformation of the blast furnace structure, cooperates with the specific ratio setting of iron ore material and coke in a specific area, so that a zinc load of about 0.25~0.3kg / t can be allowed. The reason why the relatively high zinc load does not have a responsible impact on the smelting of the present invention is that the zinc compound is reduced in the area above 1000°C in the middle and lower part of the blast furnace after entering the blast furnace, and rises with the blast furnace gas flow in a gaseous form. With the decrease of temperature, the zinc vapor condenses and is oxidized to form zinc oxide. Due to the strengthening of the central airflow in the blast furnace, a large part of it escapes from the furnace top with the coal gas and enters the dust removal ash of the blast furnace gas dust removal system, a part enters the charge, and a part of the zinc vapor enters the edge area to condense, which is conducive to forming a protective layer at the cooling wall, thereby extending the service life of the cooling wall. In this way, the dual effects of reducing costs and protecting the cooling wall are achieved.

[0018] Fourth, the present invention has found through comparative tests that the structural transformation of each part of the blast furnace and the setting of the position ratio and the adding method of iron ore and coke, as well as the range setting of zinc load have a close coordination and cooperation effect, that is, they do not play their own independent roles, but the coordination and promotion effect of one plus one is far greater than two. Through the test, the results obtained can determine that the specific settings of the above-mentioned settings are basically the optimal configuration mode, and the effects have a mutually promoting effect, which greatly improves the life of the cooling wall without affecting the smooth operation of the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 It is a schematic diagram of the blast furnace structure of the present invention; Figure 2 It is a schematic diagram of the blast furnace distribution area division of the present invention.

[0021] The symbols in the figure represent: 1. 101-furnace throat, 102-furnace body, 103-furnace waist, 104-furnace belly, 105-furnace hearth, 501-tuyere, 106-dead iron layer, h0-dead iron layer depth, h1-furnace hearth height, h2-furnace belly height, h3-furnace waist height, h4-furnace body height, h5-furnace throat height, D-furnace waist diameter, d-furnace hearth diameter, d1-furnace throat diameter, α-furnace belly angle, β-furnace body angle, A1-central area, A2-middle area, A3-external area. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Specific embodiments Unless otherwise described, each feature is only an example of a series of equivalent or similar features, which is only to help understand the present invention. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0023] like Figure 1-2 As shown, the method of the present invention comprises: Improve the blast furnace structure: increase the length of the blast furnace tuyere; adjust the inclination angle of the blast furnace tuyere small sleeve to reduce the angle between it and the horizontal plane; and set the bosh angle to less than 75°.

[0024] The tuyere length refers to the length of the tuyere sleeve extending into the furnace. In existing blast furnaces, the tuyere length is generally about 450 mm, and the tuyere sleeve angle is generally inclined at about 5°. The tuyere length of the present invention can be set to 475~490 mm, the angle of the blast furnace tuyere sleeve can be set to be in the range of -2~2° with the horizontal plane, the bosh angle of the blast furnace can be set to be less than 75° and greater than 70°, and the body angle of the blast furnace can be set to 80~85°.

[0025] The charging arrangement in the furnace is as follows: at the horizontal height section of the blast furnace throat, the circular area formed by the distance from (1.7~1.9) m to the center of the circle of the horizontal height section is designated as the central area A1; the circular ring area from the distance from (3.5~3.8) m to the center of the circle of the horizontal height section is designated as the middle area A2; the circular ring area from the distance from (3.5~3.8) m to the center of the circle of the horizontal height section to the inner wall of the furnace at the blast furnace throat is designated as the outer area A3.

[0026] During the blast furnace charging process, 80-90wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the middle zone, 5-10wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the central zone, and 5-10wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the outer zone, and the remaining iron ore materials in the central zone, middle zone and outer zone are sintered ore.

[0027] The coke can be distributed in the furnace as follows: during the blast furnace charging process, the coke distributed in the central area accounts for more than 30wt% of the total distributed coke, and the remaining coke is distributed in the middle area and the outer area at a ratio of 1:1.1 to 1:1.8.

[0028] During the blast furnace charging process, after every 4 to 8 normal charging cycles, pure coke is charged to the central area A1 separately, and the total amount of pure coke charged separately is 2 to 4 wt% of the total coke added.

[0029] The proportions of pellets, natural lump ore and sintered ore in the furnace charge are as follows: the proportion of pellets in the iron ore material is 9-12wt%, the proportion of natural lump ore is 18-22wt%, and the balance is sintered ore.

[0030] The configuration of the iron ore material allows the zinc load to be: the configuration of the iron ore material allows the blast furnace zinc load to be 0.18-0.19 kg / t.

[0031] The overall structure and proportion of the blast furnace can be set as follows: the ratio between the furnace waist diameter and the furnace hearth diameter is 1.11~1.26; the ratio between the furnace belly height and the furnace waist height is 1.51~1.72; the ratio between the furnace body height and the furnace waist height is 6.39~6.51; the ratio between the furnace waist diameter and the furnace throat diameter is 1.30~1.65. In addition, the ratio between the height from the bottom of the furnace hearth to the top of the furnace throat and the furnace waist diameter can be set to 2.38~2.62. Example 1

[0032] like Figure 1 As shown, this embodiment is modified on the basis of an existing blast furnace of a steel plant in Hebei. The effective volume of the blast furnace is 820m³, with 18 tuyere and 2 iron mouths, and a bell-less furnace top with a series of tanks. The diameter of the furnace is 6800mm, the diameter of the furnace waist is 8400mm, the diameter of the furnace throat is 5600mm, the depth of the dead iron layer is h0 is 1250mm, the height of the furnace is h1 is 3500mm, the height of the furnace belly is h2 is 2800mm, the height of the furnace waist is h3 is 1700mm, the height of the furnace body is h4 is 11000mm, the height of the furnace throat is h5 is 1700mm, the furnace belly angle α is 74.0546°, the furnace body angle β is 82.7468° (satisfying the requirement that the furnace body angle is within the range of 80~85°), the length of the tuyere is 480mm, and as shown in FIG. Figure 1 As shown, the angle of the blast furnace tuyere sleeve is set to be 0° with the horizontal plane, that is, it is set horizontally; and as obtained from the above data, its furnace bosh angle meets the requirement of being less than 75°, and the ratio between the furnace waist diameter and the furnace hearth diameter D / d=1.235, which is in the range of 1.11~1.26; and the ratio between the furnace bosh height and the furnace waist height h2 / h3=1.647, which is in the range of 1.51~1.72.

[0033] And at the horizontal height section of the blast furnace throat, the circular area formed from 1.8m away from the center of the horizontal height section to the center of the circle is defined as the central area, the circular area from 3.6m away from the center of the horizontal height section to 1.8m away from the center of the horizontal height section is defined as the middle area, and the circular area from 3.6m away from the center of the horizontal height section to the furnace inner wall of the blast furnace throat is defined as the outer area. In the blast furnace charging process, 88wt% of the total amount of pellets and natural lumps in the iron ore are charged through the middle area, 6wt% of the total amount of pellets and natural lumps in the iron ore are charged through the central area, and 6wt% of the total amount of pellets and natural lumps in the iron ore are charged through the outer area, and the remaining iron ore in the central area, the middle area and the outer area are sintered ore. In the iron ore material of this embodiment, the proportion of pelletized ore is 10wt%, the proportion of natural lump ore is 20wt%, and the balance is sintered ore.

[0034] During the blast furnace charging process, the coke distributed in the central area accounts for 39wt% of the total coke distributed, and the remaining coke is distributed in the middle area and the outer area at a ratio of 1:1.2.

[0035] During the blast furnace charging process, after every 6 normal charging cycles, pure coke is charged to the central area separately, and the total amount of pure coke charged separately is 3wt% of the total coke added.

[0036] In this embodiment, the iron ore materials entering the furnace are tested, and it is found that the zinc entering the blast furnace is mainly brought into the blast furnace by sintered ore, pelletized ore and lump ore, of which 55.28% is brought in by sintered ore, 21.95% is brought in by pelletized ore, and 2% is brought in by natural lump ore. In this embodiment, the zinc content of sintered ore and pelletized ore is configured so that the zinc load of the blast furnace is 0.25~0.3kg / t (the addition of iron ore materials will inevitably not be the same every time, and it can basically be controlled within this range).

[0037] By testing the cooling wall burnout of the blast furnace of this embodiment, it was found that the burnout was still slight after 10 months. Comparative Example 1

[0038] This comparative example is an existing blast furnace in a steel plant in Hebei Province, which has an effective volume of 816m³, 18 tuyere ports, 2 iron ports, and a bell-less furnace top. The furnace diameter d is 6800mm, the furnace waist diameter D is 8100mm, the furnace throat diameter d1 is 5500mm, the dead iron layer depth h0 is 1250mm, the furnace height h1 is 3500mm, the furnace belly height h2 is 2900mm, the furnace waist height h3 is 1800mm, the furnace body height h4 is 11500mm, the furnace throat height h5 is 2000mm, the furnace belly angle α is 77.3667° (i.e., its furnace belly angle does not meet the requirement of less than 75°), and the furnace body The angle β is 83.5505°, the tuyere length is 450 mm (not within the range of 475 to 490 mm defined in the present invention), and the blast furnace tuyere sleeve is tilted downward (i.e., tilted downward toward the interior of the blast furnace), and its downward tilt angle is set to be 5° with the horizontal plane (not within the range of -2 to 2° defined in the present invention), and the ratio of the blast furnace body height to the furnace waist height h4 / h3=6.389 (not within the range of 6.39 to 6.51).

[0039] Other settings, such as the blast furnace charging process and the blast furnace zinc load setting, are exactly the same as those in Example 1.

[0040] The six cooling walls of the blast furnace were inspected every month. It was found that two months after the blast furnace was opened, the cooling walls were damaged to varying degrees, with a damage rate of 57%. Some even had cooling water pipes exposed. This was due to the shortened length of the tuyere and the large tuyere angle (there was a vector in the vertical direction after the airflow entered), and the large belly angle, which caused the airflow at the edge of the blast furnace to overdevelop, resulting in heat accumulation near the cooling wall. After the edge airflow was overdeveloped, the furnace charge at the belly of the furnace went down and the coal gas went up. The relative movement of the two exerted great friction on the furnace wall, further strengthening the damage. Multiple factors caused the damage to the cooling wall. Comparative Example 2

[0041] This comparative example still uses the existing blast furnace of a steel plant in Hebei Province in comparative example 1, but pelletized ore and natural lump ore are not restricted in conventional distribution during distribution, and coke is also conventionally arranged in each area according to the normal ore-coke ratio, and the arrangement of iron ore materials is the same as in Example 1.

[0042] The cooling wall of the comparative example was tested every month, and it was found that the burnout rate of the six cooling walls had reached 60% one month after the blast furnace was opened. It was also found that the binary basicity of the initial slag in the outermost ring close to the blast furnace wall was 0.73, which means that the basicity of the initial slag formed by the outermost ring distribution is much lower than the basicity of the blast furnace final slag (the basicity of the blast furnace final slag is generally about 1.25, while the basicity of the sintered ore is about 1.9~2.0), that is, the melting point of the outermost ring material is relatively low (the melting temperature increases when the basicity of the slag increases), and it is easier to melt, and the distribution of coke in the central area is too low, so that the development of the central airflow cannot be guaranteed, and combined with the short blast furnace tuyere and large furnace belly angle, the airflow is easy to develop to the edge position, thereby accelerating the burning of the cooling wall. Comparative Example 3

[0043] This comparative example adopts the improved blast furnace in Example 1, but when distributing the materials, the pellets and natural lump ores are not restricted to carry out conventional distribution in the existing manner (i.e., the pellets and natural lump ores are evenly distributed in various areas), and the coke is also conventionally arranged in various areas according to the normal ore-coke ratio (i.e., the coke addition in the central area is less than 30%, while that in the edge is higher than 35%, and there is no periodic cycle of adding coke in the central area), and the setting of the iron ore material is the same as that in Example 1. The cooling wall of this comparative example is tested every month, and it is found that after 2 months of opening the furnace, the burnout rate of the 6-section cooling wall has reached 60%. The main reason is similar to that of Comparative Example 2. Although the blast furnace structure has been improved, the burnout time has only been extended by 1 month. That is, the distribution method of ore and coke of the present invention is closely coordinated with the improvement of the blast furnace structure, and has a close coordination effect. For example, in Comparative Examples 1 and 3, both the structure and the ingredients were improved separately, and it was found that the improvement effect was very limited. However, in Example 1, several methods were combined, and the improvement effect was greatly improved. After years of development, the blast furnace smelting technology has greatly improved in intelligence, but due to its high temperature, high pressure, closed and continuous production characteristics, it still determines that it has certain "black box" characteristics, and its internal information cannot be fully obtained. It is a typical experimental modification. The principle deduction can only be carried out by independent factors, but the influencing factors in the actual production process are coordinated with each other. This shows that the measures set by the present invention do not each achieve their own independent effects, but have a very good coordinated effect, that is, the coordination effect of 1+1 far>2 appears. Comparative Example 4

[0044] The other settings of this comparative example are exactly the same as those of Example 1, except that the blast furnace zinc load is 0.15 kg / t (more than half of the zinc load is brought in by the sintered ore, and more than one-fifth is brought in by the pelletized ore) after further screening of the sintered ore, pelletized ore and natural lump ore. After such settings, after the 10th month, it was found that the burning loss of the blast furnace cooling wall was about 30 percentage points higher than that of Example 1, and the cost also increased by 1 to 2 percentage points due to the control of the zinc load. The reason for this is that Example 1 of the present invention sets a relatively high zinc load, which is beneficial to form a certain protective layer on the cooling wall, while excessive pursuit of a low zinc load is not conducive to the formation of a protective layer on the cooling wall. Comparative Example 5

[0045] The other settings of this comparative example are exactly the same as those of comparative example 1, except that the blast furnace tuyere sleeve is set to be tilted upward, and the angle of its upward tilt is set to be 5° with the horizontal plane (also not within the range of -2~2° specified by the present invention, and is set to be tilted upward). Similarly, the 6 sections of cooling walls of the blast furnace are tested every month, and it is found that the burnout rate of the cooling walls has reached 63% after 2 months of furnace opening, and the burnout is more serious than that of comparative example 1, which shows that the too short tuyere setting combined with the upward tilted tuyere will further strengthen the excessive development of the edge airflow. The basic horizontal setting (-2~2°) of the present invention combined with the tuyere of appropriately extended length will strengthen the development of the central airflow, which will become one of the factors for extending the service life of the cooling wall and has the most optimized coordination with other settings.

[0046] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A method for extending the service life of a blast furnace cooling wall, characterized in that: The method comprises: (1) Improve the blast furnace structure: extend the length of the blast furnace tuyere; adjust the inclination angle of the blast furnace tuyere sleeve to reduce the angle between it and the horizontal plane; and set the furnace bosh angle to less than 75°; (2) The charging arrangement in the furnace is as follows: at the horizontal section at the throat of the blast furnace, the circular area from the center of the circle (1.7-1.9) m of the horizontal section to the center of the circle is defined as the central area A1; the circular area from the center of the circle (3.5-3.8) m of the horizontal section to the center of the circle (1.7-1.9) m of the horizontal section is defined as the middle area A2; the circular area from the center of the circle (3.5-3.8) m of the horizontal section to the inner wall of the blast furnace throat is defined as the outer area A3; During the blast furnace charging process, 80-90wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the middle zone, 5-10wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the central zone, and 5-10wt% of the total amount of pellets and natural lumps in the iron ore material is charged through the outer zone, and the remaining iron ore materials in the central zone, middle zone and outer zone are sintered ore.

2. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: The length of the blast furnace tuyere is set to 475~490mm, and the angle of the blast furnace tuyere sleeve is set to be within the range of -2~2° with the horizontal plane.

3. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: During the blast furnace charging process, the coke distributed in the central zone accounts for more than 30wt% of the total coke distributed, and the remaining coke is distributed in the middle zone and the outer zone at a ratio of 1:1.1 to 1:1.

8.

4. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: During the blast furnace charging process, after every 4 to 8 normal charging cycles, pure coke is charged to the central area A1 separately, and the total amount of pure coke charged separately is 2 to 4 wt% of the total coke added.

5. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: The iron ore material comprises 9-12wt% of pelletized ore, 18-22wt% of natural lump ore, and the remainder is sintered ore.

6. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: The iron ore material is configured so that the blast furnace zinc load is 0.18-0.19 kg / t.

7. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: Set the blast furnace belly angle less than 75° and greater than 70°.

8. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: The proportion of coke distributed in the central area to the total distributed coke is greater than 30wt% and less than 45wt%.

9. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: Set the blast furnace body angle to 80~85°.

10. The method for extending the service life of a blast furnace cooling stave according to claim 1, characterized in that: The overall structure and proportions of the blast furnace are set as follows: the ratio between the furnace waist diameter and the furnace hearth diameter is 1.11~1.26; the ratio between the furnace belly height and the furnace waist height is 1.51~1.72; the ratio between the furnace body height and the furnace waist height is 6.39~6.51; the ratio between the furnace waist diameter and the furnace throat diameter is 1.30~1.65.

Images