Method for preventing tuyere small sleeve from being frequently damaged in blast furnace smelting process

Abstract

The invention discloses a method for preventing frequent damage of a tuyere small sleeve in a blast furnace smelting process and belongs to the technical field of ironmaking processes. The blast furnace tuyere small sleeve solves the problem that an existing blast furnace tuyere small sleeve is frequently damaged in the smelting process. The method specifically comprises the following steps that S1, the content of Si in molten iron is increased to 0.5%-0.7% from original 0.3%-0.5%, and the temperature of the molten iron is increased to be larger than or equal to 1500 DEG C from original 1480-1500 DEG C; s2, the original coke ratio of 340 kg / t < Fe > to 350 kg / t < Fe > is increased to 360 kg / t < Fe > to 390 kg / t < Fe >; by means of the measures of increasing the Si content in the molten iron, reducing the coke load, adjusting the material distribution matrix, developing edge and center airflow and the like, it is guaranteed that the temperature of slag iron in the blast furnace is abundant, fluidity is good, airflow distribution is reasonable and smooth, and slag iron discharging is orderly, so that frequent damage of the tuyere small sleeve is avoided, and it is guaranteed that the temperature of a blast furnace hearth is sufficient; the hearth works uniformly and actively, and long-term stable and smooth operation of the blast furnace is ensured.

Description

Technical Field

[0001] This invention relates to the field of ironmaking technology, and more specifically, to a method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting. Background Technology

[0002] The tuyere, located at the upper part of the blast furnace hearth, at the junction of the hearth and belly, is the area where the initial gas is generated. During operation, it must withstand the scouring and physical impact of high-temperature blast (around 1200℃), molten slag and iron (around 1500℃), and rapidly circulating hot materials. The outer surface of the tuyere also endures convective heat transfer from the high-temperature blast and molten slag and iron. Therefore, the working conditions of the tuyere are extremely harsh. The service life of the blast furnace tuyere directly affects normal blast furnace production. Frequent tuyere damage not only disrupts the normal production rhythm but also affects furnace operation and increases fuel consumption. Tuyere burn-through caused by damage is the most serious safety accident in blast furnace ironmaking. If tuyere damage is not handled properly, a burn-through accident can result in a large amount of high-temperature, molten slag and iron spraying out of the furnace, causing equipment damage, personnel burns, and other accidents, severely impacting the safety of the enterprise.

[0003] A method for preventing frequent damage to the tuyere sleeve during blast furnace smelting is hereby invented, so as to avoid frequent damage to the tuyere sleeve and achieve long-term stable operation of the blast furnace. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned problems and provides a method to prevent frequent damage to the tuyeres sleeve during blast furnace smelting.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problems is: a method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting, specifically including the following steps: S1: Increase the Si content in the molten iron from the original 0.3%~0.5% to 0.5%~0.7%, and increase the temperature of the molten iron from the original 1480℃~1500℃ to ≥1500℃; S2: Increase the original coke ratio from 340 kg / t•Fe ~ 350 kg / t•Fe to 360 kg / t•Fe ~ 390 kg / t•Fe; S3: Increase the number of coke rings in the center of the original 3 rings to 3.5 to 4 rings, adjust the number of coke rings on the edge of the original 2 rings to 3 rings, or reduce the number of ore rings on the edge of the original 3 rings to 2 rings; S4: Adjust the original discharge order of sinter, coke, and pellets to coke, pellets, and sinter. S5: Adjust the original theoretical combustion temperature of 2200℃~2300℃ to 2300±50℃; S6: Adjust the magnesium-aluminum ratio in the original slag from 0.6~0.65 to 0.7~0.85; S7: Adjust the original slag ratio of 350 kg / t•Fe ~ 360 kg / t•Fe to 355 kg / t•Fe ~ 370 kg / t•Fe; S8: Adjust the original iron tapping frequency from 9 times to 12 times.

[0006] Furthermore, in S1, the Si content and temperature of the molten iron are increased by raising the blast temperature from 1180°C to 1190°C-1210°C or by increasing the fuel ratio from 510 kg / t•Fe ~ 520 kg / t•Fe to 520 kg / t•Fe ~ 540 kg / t•Fe.

[0007] Furthermore, the theoretical combustion temperature is adjusted in S5 by increasing the blower temperature.

[0008] Furthermore, in S6, the magnesium oxide content in the sinter is increased by increasing the proportion of magnesite powder in the sinter, thereby adjusting the magnesium-aluminum ratio in the slag.

[0009] Furthermore, in S7, the slag ratio is adjusted by increasing the proportion of magnesite powder in the sinter or by adding silica.

[0010] Furthermore, the original iron tapping process in S8 involved two iron tapping ports alternating at fixed intervals. Now, the original iron tapping process is adjusted to have the two iron tapping ports alternating at zero intervals to increase the iron tapping frequency.

[0011] Furthermore, the operating status of the online air vent sleeves should be checked regularly, and any damaged sleeves should be replaced centrally.

[0012] Compared with the prior art, the present invention has the following advantages: This invention ensures sufficient slag and iron temperature, good fluidity, reasonable and smooth airflow distribution, and orderly slag and iron discharge in the blast furnace by increasing the Si content in molten iron, reducing coke load, adjusting the charging matrix, and developing edge and center airflow. This avoids frequent damage to the tuyeres sleeve, ensures sufficient blast furnace hearth temperature, uniform and active hearth operation, and ensures long-term stable and smooth operation of the blast furnace. Detailed Implementation

[0013] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0016] In the description of this invention, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0017] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0018] In this embodiment, a method for preventing frequent damage to the tuyere sleeve during blast furnace smelting specifically includes the following steps: S1: Increase the Si content in the molten iron from the original 0.3%~0.5% to 0.5%~0.7%, and increase the temperature of the molten iron from the original 1480℃~1500℃ to ≥1500℃; S2: Increase the original coke ratio from 340 kg / t•Fe ~ 350 kg / t•Fe to 360 kg / t•Fe ~ 390 kg / t•Fe; S3: Increase the number of coke rings in the center of the original 3 rings to 3.5 to 4 rings, adjust the number of coke rings on the edge of the original 2 rings to 3 rings, or reduce the number of ore rings on the edge of the original 3 rings to 2 rings; S4: Adjust the original discharge order of sinter, coke, and pellets to coke, pellets, and sinter. S5: Adjust the original theoretical combustion temperature of 2200℃~2300℃ to 2300±50℃; S6: Adjust the magnesium-aluminum ratio in the original slag from 0.6~0.65 to 0.7~0.85; S7: Adjust the original slag ratio of 350 kg / t•Fe ~ 360 kg / t•Fe to 355 kg / t•Fe ~ 370 kg / t•Fe; S8: Adjust the original iron tapping frequency from 9 times to 12 times.

[0019] In S2, increasing the coke ratio reduces the coke load and fully utilizes the skeletal role of coke in the blast furnace burden, creating favorable conditions for the upward flow of gas and the dripping of molten slag and iron. In S3, adjusting the material distribution matrix allows for the simultaneous development of edge and center airflow, thereby ensuring sufficient blast furnace hearth temperature and effectively preventing frequent damage to the tuyeres. In S4, optimizing the discharge sequence places the coke nuts before the sinter and pellets, ensuring that the coke nuts are distributed at the edge of the furnace wall, reducing the slag produced during the combustion of sinter and pellets from adhering to the inner wall of the furnace, and helping to improve the uniformity and activity of the hearth operation.

[0020] In S1, the Si content and temperature of the molten iron are increased by raising the blast temperature from 1180℃ to 1190℃-1210℃ or by increasing the fuel ratio from 510 kg / t•Fe ~ 520 kg / t•Fe to 520 kg / t•Fe ~ 540 kg / t•Fe. Specifically, the combustion ratio is the total amount of coke and pulverized coal required to smelt one ton of iron. By increasing the blast temperature or the fuel ratio, the Si content and temperature of the molten iron are increased, ensuring good fluidity of the molten iron and slag, preventing high-temperature molten iron from splashing onto the tuyeres, thereby reducing frequent damage to the tuyeres.

[0021] In S5, the theoretical combustion temperature is adjusted by increasing the blast temperature. Specifically, if the theoretical combustion temperature is too high, a large amount of silica will be generated, affecting the overall permeability of the material column; if the theoretical combustion temperature is too low, the temperature at the front end of the tuyeres will be insufficient, affecting the free flow of slag and iron.

[0022] In S6, the magnesium oxide content in the sinter is increased by increasing the proportion of magnesia powder, thereby adjusting the magnesium-aluminum ratio in the slag. Increasing the magnesium-aluminum ratio can effectively lower the melting temperature of the slag, improve its fluidity, stabilize furnace conditions, and increase the alkali discharge rate.

[0023] In S7, the slag ratio is adjusted by increasing the proportion of magnesite powder in the sinter or by adding silica. Increasing the slag ratio can increase the heat of the hearth, improve the working condition of the hearth, alleviate hearth buildup, and increase the discharge of alkali metals through the slag.

[0024] The original iron tapping process in S8 involved two tapping ports alternating at fixed intervals. Now, the original iron tapping process has been adjusted to have the two tapping ports alternating at zero intervals to increase the frequency of iron tapping and thus reduce the amount of slag and iron accumulating in the hearth.

[0025] Regularly check the operating status of the online tuyer sleeves and replace them if damaged. Replacing the tuyer sleeves ensures that cooling water does not enter the furnace hearth in large quantities, guaranteeing sufficient temperature at the tuyer front end and in the furnace hearth.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preventing frequent damage to the tuyere sleeve during blast furnace smelting, characterized in that, Specifically, the following steps are included: S1: Increase the Si content in the molten iron from the original 0.3%~0.5% to 0.5%~0.7%, and increase the temperature of the molten iron from the original 1480℃~1500℃ to ≥1500℃; S2: Increase the original coke ratio from 340 kg / t•Fe ~ 350 kg / t•Fe to 360 kg / t•Fe ~ 390 kg / t•Fe; S3: Increase the number of coke rings in the center of the original 3 rings to 3.5 to 4 rings, adjust the number of coke rings on the edge of the original 2 rings to 3 rings, or reduce the number of ore rings on the edge of the original 3 rings to 2 rings; S4: Adjust the original discharge order of sinter, coke, and pellets to coke, pellets, and sinter. S5: Adjust the original theoretical combustion temperature of 2200℃~2300℃ to 2300±50℃; S6: Adjust the magnesium-aluminum ratio in the original slag from 0.6~0.65 to 0.7~0.85; S7: Adjust the original slag ratio of 350 kg / t•Fe ~ 360 kg / t•Fe to 355 kg / t•Fe ~ 370 kg / t•Fe; S8: Adjust the original iron tapping frequency from 9 times to 12 times.

2. The method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting according to claim 1, characterized in that: In S1, the Si content and temperature of the molten iron are increased by raising the blast temperature from 1180℃ to 1190℃-1210℃ or by increasing the fuel ratio from 510 kg / t•Fe ~ 520 kg / t•Fe to 520 kg / t•Fe ~ 540 kg / t•Fe.

3. The method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting according to claim 1, characterized in that: In S5, the theoretical combustion temperature is adjusted by increasing the blower temperature.

4. The method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting according to claim 1, characterized in that: In S6, the magnesium oxide content in the sinter is increased by increasing the proportion of magnesite powder in the sinter, thereby adjusting the magnesium-aluminum ratio in the slag.

5. The method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting according to claim 1, characterized in that: In S7, the slag ratio is adjusted by increasing the proportion of magnesite powder in the sinter or by adding silica.

6. The method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting according to claim 1, characterized in that: The original iron tapping process in S8 involved two tapping ports alternating at fixed intervals. Now, the original iron tapping process is adjusted to have the two tapping ports alternating at zero intervals to increase the tapping frequency.

7. The method for preventing frequent damage to the tuyeres sleeve during blast furnace smelting according to claim 1, characterized in that: Regularly check the operating status of the online air vent sleeves and replace them in a centralized manner if they are damaged.