Method for maintaining large surface of converter

Abstract

The invention relates to a method for maintaining a large surface of a converter. The method comprises the following steps: determining the maintenance area of the large surface of the converter; according to the maintenance area of the converter large surface, the adding amount of steel bar pelletizing is determined; after tapping of the converter, the steel bar particles are poured into the converter, and the tilting angle of a converter body of the converter is adjusted, so that the steel bar particles are flatly laid on the maintenance part; and the slag in the converter completely submerges the steel bar cutting particles laid on the maintenance part, the slag is condensed synchronously, a protection layer with the slag wrapping the steel bar cutting particles is formed on the surface of the converter large face, and converter large face maintenance is completed. According to the converter large-area maintenance method, the steel bar cut particles rapidly enter the slag and rapidly cool the slag, so that gaps among the steel bar cut particles are filled with the slag and the steel bar cut particles are wrapped by the slag, the slag-wrapped steel bar cut particle protection layer is adhered to the surface of the converter lining in the slag condensation process, and the converter large-area maintenance effect is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of converter smelting, and in particular to a method for maintaining a large surface of a converter. Background Art

[0002] The front surface of the oxygen top-blown converter is often subjected to mechanical erosion when loading molten iron and scrap steel, and needs frequent repairs, which takes up a lot of production time. Common furnace repair and maintenance methods include feeding and spraying, which have the following disadvantages: the furnace repair time is long, at least 30 minutes per time; the main material of the furnace repair refractory is magnesium-containing and carbon-containing raw materials, and a large amount of waste smoke and waste gas are generated during production and use; the furnace repair refractory is a consumable material, which increases the operating cost of the converter; the corrosion resistance after repair with furnace repair material is unstable, and the service life cycle is uncertain, which is not conducive to the orderly production of the converter.

[0003] Therefore, it is necessary to improve the furnace repair method and optimize the furnace repair materials to achieve efficient converter production and reduce environmental pollution. Summary of the invention

[0004] The present application provides a method for maintaining a large surface of a converter to solve the following technical problem: providing a new method for maintaining a large surface of a converter.

[0005] In a first aspect, the present application provides a method for maintaining a large surface of a converter, the method comprising:

[0006] Determine the maintenance area of ​​the converter's large surface;

[0007] Determine the amount of steel bar pellets added according to the maintenance area of ​​the converter;

[0008] After the converter taps out steel, the steel bar pellets are poured into the converter, and the tilting angle of the converter body is adjusted so that the steel bar pellets are laid flat on the maintenance position;

[0009] The slag in the converter is completely submerged in the steel bar pellets spread on the maintenance position, and condensed simultaneously to obtain a large converter surface with a protective layer of slag wrapped steel bar pellets on the surface, so as to complete the maintenance of the large converter surface.

[0010] Optionally, the particle size of the steel bar pellets is 100 mm to 500 mm.

[0011] Optionally, determining the amount of steel bar pellets to be added according to the maintenance area of ​​the large surface of the converter includes:

[0012] Relative to the maintenance area of ​​1 m2 of the large surface of the converter, the amount of steel bar pellets added is 0.27t to 0.67t.

[0013] Optionally, the condensation time is 1 min to 3 min.

[0014] Optionally, the adjusting the tilting angle of the furnace body of the converter so that the steel bar pellets are laid flat on the maintenance position includes:

[0015] The large surface of the converter is evenly divided into three parts: upper, middle and lower. The converter is placed vertically with the horizontal plane as the reference angle, and the tilting angle of the converter body is adjusted so that the steel bar pellets are laid flat on the maintenance position; wherein,

[0016] When maintaining the large surface of the converter, the tilting angle of the converter body is adjusted to 70° to 85°;

[0017] When maintaining the middle part of the large surface of the converter, the tilting angle of the converter body is adjusted to 60° to 75°;

[0018] When maintaining the lower portion of the large surface of the converter, the tilting angle of the converter body is adjusted to 45° to 60°.

[0019] Optionally, the chemical composition of the steel bar pellets includes: C≤1.0wt%, Mn≤2.0wt%, P≤0.1wt%, S≤0.1wt%.

[0020] Optionally, the method further includes:

[0021] The converter having a large converter surface with a protective layer of slag wrapped steel bar pellets is shaken to splash slag, and the position of the oxygen lance is controlled until the slag is splashed and poured out, so as to carry out the next furnace smelting.

[0022] Optionally, the oxygen lance is located at a height of 1m to 1.5m.

[0023] Optionally, the total iron content of the converter slag is 14.5wt% to 18wt%, and the basicity of the converter slag is 2.8 to 3.5.

[0024] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0025] The method for the maintenance of the large surface of the converter provided in the embodiment of the present application includes: determining the maintenance area of ​​the large surface of the converter; determining the amount of steel bar pellets to be added according to the maintenance area of ​​the large surface of the converter; pouring the steel bar pellets into the converter after the converter taps out steel, and adjusting the tilting angle of the furnace body of the converter so that the steel bar pellets are spread flat on the maintenance position; the slag in the converter is completely submerged in the steel bar pellets spread flat on the maintenance position, and then condensed to obtain a large surface of the converter with a protective layer of slag wrapped steel bar pellets on the surface, so as to complete the maintenance of the large surface of the converter. The steel bar pellets are spread flat on the maintenance position of the large surface of the converter, and the slag in the converter completely submerges the steel bar pellets spread flat on the maintenance position. The density of the steel bar pellets is greater than the density of the slag, so that the steel bar pellets can quickly enter the slag and quickly cool the slag, so that the slag fills the gaps between the steel bar pellets and wraps the steel bar pellets. During the condensation process of the slag, it adheres to the surface of the converter lining with a protective layer of slag wrapped steel bar pellets, thereby achieving the maintenance of the large surface of the converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] Figure 1 A schematic flow chart of a method for large-surface maintenance of a converter provided in an embodiment of the present application;

[0029] Figure 2 An appearance diagram of a steel bar pelletizing provided in an embodiment of the present application;

[0030] Figure 3 This is an on-site maintenance appearance diagram of a method for large-surface maintenance of a converter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0033] In this application, the terms "including", "comprising", etc. mean "including but not limited to".

[0034] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0035] In a first aspect, the present application provides a method for maintaining a large surface of a converter. Figure 1 A schematic diagram of a method for maintaining a large surface of a converter provided in an embodiment of the present application; see Figure 1 , the method comprising:

[0036] S1. Determine the maintenance area of ​​the large surface of the converter;

[0037] S2. Determine the amount of steel bar pellets added according to the maintenance area of ​​the large surface of the converter;

[0038] In some embodiments, the steel bar pellets have a particle size of 100 mm to 500 mm.

[0039] In the embodiment of the present application, the leftover steel bars of appropriate specifications are processed into 100 mm to 500 mm in length, and the slag fully fills the gaps between the steel bars to facilitate cooling of the slag. Figure 2 This is an appearance diagram of a steel bar pellet provided in an embodiment of the present application; see Figure 2 For example, the particle size of the steel bar pellets may be 100 mm, 200 mm, 300 mm, 400 mm, 500 mm, etc.

[0040] In some embodiments, the method of determining the amount of steel bar pellets to be added according to the maintenance area of ​​the converter includes:

[0041] Relative to the maintenance area of ​​1 m2 of the large surface of the converter, the amount of steel bar pellets added is 0.27t to 0.67t.

[0042] In the embodiment of the present application, the amount of steel bar pellets added is 0.27t to 0.67t relative to the maintenance area of ​​the large converter surface of 1㎡, so that the steel bar pellets can be laid flat on the maintenance position of the large converter surface. Exemplarily, the amount of steel bar pellets added can be 0.27t, 0.3t, 0.35t, 0.4t, 0.45t, 0.5t, 0.55t, 0.6t, 0.67t, etc. relative to the maintenance area of ​​the large converter surface of 1㎡.

[0043] S3, after the steel is tapped from the converter, pouring the steel bar pellets into the converter, and adjusting the tilting angle of the converter body so that the steel bar pellets are laid flat on the maintenance position;

[0044] In some embodiments, the step of adjusting the tilting angle of the converter body so that the steel bar pellets are laid flat on the maintenance position includes:

[0045] The large surface of the converter is evenly divided into three parts: upper, middle and lower. The converter is placed vertically with the horizontal plane as the reference angle, and the tilting angle of the converter body is adjusted so that the steel bar pellets are laid flat on the maintenance position; wherein,

[0046] When maintaining the large surface of the converter, the tilting angle of the converter body is adjusted to 70° to 85°;

[0047] When maintaining the middle part of the large surface of the converter, the tilting angle of the converter body is adjusted to 60° to 75°;

[0048] When maintaining the lower portion of the large surface of the converter, the tilting angle of the converter body is adjusted to 45° to 60°.

[0049] In an embodiment of the present application, the large surface of the converter is evenly divided into three parts: upper, middle and lower. The converter is placed vertically with the horizontal plane as the reference angle. When maintaining the upper part of the large surface of the converter, the tilting angle of the converter body is adjusted to 70°~85°; when maintaining the middle part of the large surface of the converter, the tilting angle of the converter body is adjusted to 60°~75°; when maintaining the lower part of the large surface of the converter, the tilting angle of the converter body is adjusted to 45°~60°, so as to ensure that the steel bar cut particles are laid flat on the maintenance position.

[0050] In some embodiments, the chemical composition of the steel bar pellets includes: C≤1.0wt%, Mn≤2.0wt%, P≤0.1wt%, S≤0.1wt%.

[0051] In the embodiment of the present application, the chemical composition of the steel bar pellets includes: C≤1.0wt%, Mn≤2.0wt%, P≤0.1wt%, S≤0.1wt%, so that the steel bar pellets have a certain density (higher than the density of converter slag), and have good corrosion resistance during the converter smelting process, and do not affect the quality of molten steel after melting.

[0052] In some embodiments, the total iron content of the converter slag is 14.5wt% to 18wt%, and the basicity of the converter slag is 2.8 to 3.5.

[0053] In the embodiment of the present application, the total iron content of the converter slag is limited to 14.5wt% to 18wt%, and the basicity of the converter slag is 2.8 to 3.5, which can fully ensure the fluidity of the converter slag. Exemplarily, the total iron content of the above converter slag can be 14.5wt%, 15wt%, 16wt%, 17wt%, 18wt%, etc., and the basicity of the converter slag can be 2.8, 3.0, 3.2, 3.4, 3.5, etc.

[0054] S4, completely submerge the steel bar pellets spread on the maintenance position with the slag in the converter, and then condense them to obtain a converter surface with a protective layer of slag wrapped steel bar pellets, so as to complete the converter surface maintenance.

[0055] In some embodiments, the condensation time is 1 min to 3 min.

[0056] In the embodiment of the present application, the slag in the converter is liquid, and the liquid slag will adhere to the surface of the furnace lining during the condensation process. 3 ) is greater than the slag density (3.2t / m 3 ), so that it quickly enters the slag and cools the slag quickly; the liquid slag fills the gaps between the steel bar particles, wraps the steel bar particles, and adheres to the surface of the converter lining during the condensation of the slag and steel for 1min to 3min to form a protective layer of a certain thickness, which can achieve a protective effect. Figure 3 A method for large-surface maintenance of a converter provided in an embodiment of the present application is provided for on-site maintenance appearance diagram; see Figure 3 , indicating that a condensation layer of a certain thickness is formed on the large surface of the converter, which plays a role in alleviating the erosion of the converter lining and achieves the expected effect of the maintenance of the large surface of the converter (the front large surface can be maintained for at least 8 hours.

[0057] Exemplarily, the condensation time may be 1 min, 1.5 min, 2.0 min, 2.5 min, 3 min, etc.

[0058] In some embodiments, the method further comprises:

[0059] The converter having a large converter surface with a protective layer of slag wrapped steel bar pellets is shaken to splash slag, and the position of the oxygen lance is controlled until the slag is splashed and poured out, so as to carry out the next furnace smelting.

[0060] In some embodiments, the oxygen lance is located at a height of 1 m to 1.5 m.

[0061] In the embodiment of the present application, the slag can be condensed in advance by shaking the furnace to quickly form a slag layer on the surface of the converter lining; the oxygen lance position is limited to 1m to 1.5m, which can reduce the impact of high-pressure airflow on the steel bar pellets that have adhered to the large surface of the converter but have not been completely condensed, causing them to fall. Exemplarily, the oxygen lance position can be 1m, 1.1m, 1.2m, 1.3m, 1.4m, 1.5m, etc.

[0062] A method for large-surface maintenance of a converter provided in an embodiment of the present application can form an effective corrosion-resistant layer on the surface of the furnace lining. When adding iron or loading scrap steel, the furnace lining will no longer be directly impacted. It can also play a role of high-temperature erosion resistance during the smelting period, thereby achieving the purpose of reducing corrosion. The time for repairing the furnace is as short as 1-3 minutes, the corrosion resistance is relatively stable and can reach more than 8 hours, and no waste flue gas is generated during production and use, thereby reducing the consumption of consumables for repairing the furnace. Compared with repairing the furnace with charge, the consumption of refractory materials can be reduced by 1 yuan / ton of steel.

[0063] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0064] Example 1

[0065] A method for maintaining a large surface of a converter, comprising:

[0066] S11. Determine the maintenance area of ​​the large surface of the converter;

[0067] S21, determining the amount of steel bar pellets added according to the maintenance area of ​​the large surface of the converter;

[0068] S31, after the converter taps out steel, pouring the steel bar pellets into the converter, and adjusting the tilting angle of the converter body so that the steel bar pellets are laid flat on the maintenance position;

[0069] S41, completely submerge the steel bar pellets spread on the maintenance position with the slag in the converter, and then condense them to obtain a converter surface with a protective layer of slag wrapped steel bar pellets, so as to complete the converter surface maintenance.

[0070] At 5:38 on March 10, 2024, after the 7313th heat was tapped, 1.5 tons of steel bar granulated condensed slag was used to maintain the front large surface of the 7# converter. Please refer to the process parameters of the first maintenance in Table 1, and the lining operation data was tracked. Please refer to the large surface data before the first maintenance converter thickness measurement shown in Table 2; at 13:45, after the 7323th heat was tapped, 0.9 tons of steel bar granulated condensed slag was used to maintain the front large surface of the 7# converter again. Please refer to the process parameters of the second maintenance in Table 1, and the lining operation data was tracked. Please refer to the large surface data before the second maintenance converter thickness measurement shown in Table 3. Therefore, please refer to the physical and chemical indicators of steel bar granulation and the location of converter large surface maintenance shown in Table 1, the lining thickness tracking data after the first converter large surface maintenance shown in Table 2, and the lining thickness tracking data after the second converter large surface maintenance shown in Table 3.

[0071] Table 1 Physical and chemical indicators of steel bar cutting and location of converter large surface maintenance

[0072]

[0073] Table 2 Tracking data of lining thickness after the first converter large surface maintenance

[0074]

[0075] Table 3 Tracking data of lining thickness after the second converter large surface maintenance

[0076]

[0077] From the records of the first maintenance and the second maintenance, it can be seen that the corrosion resistance after the large surface is repaired with steel bar cuttings is relatively stable, and the service life is stable at 8 hours, which is conducive to the orderly production of the converter.

[0078] Comparative Example 1

[0079] At 10:32 on November 5, 2022, after the 7203 heat was tapped, 3 tons of magnesium-carbon raw materials were used to replenish the large surface in front of the 7# furnace. The sintering time of the replenishment charge was as long as 60 minutes, and the process generated a lot of smoke. In order to ensure that the smoke and dust did not overflow, the dust removal fan was operated for 30 minutes during the period. As of 8:05 on November 5, the four-o'clock shift found that the replenishment charge had been eroded and the production requirements had to be coordinated for replenishment. Because the production rhythm could not be disrupted, there was no opportunity to replenish the furnace until 3:05 on November 6. 2 tons of replenishment charge were used again to replenish the large surface in front of the 7# furnace, and the sintering time of the replenishment charge was 45 minutes.

[0080] In summary, from the above two methods of furnace repair and maintenance, it can be seen that the method of large-surface maintenance of a converter provided by the present application does not affect the production rhythm and the furnace repair time is short. The corrosion resistance after repair is relatively stable, and the converter can be produced in an orderly manner. At the same time, this method does not generate waste flue gas and meets environmental protection requirements. Therefore, compared with the traditional refractory material maintenance furnace lining method (Comparative Example 1), the economic, practical, and environmental protection values ​​are greatly improved.

[0081] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for maintaining a large surface of a converter, characterized in that: The method comprises: Determine the maintenance area of ​​the converter's large surface; Determine the amount of steel bar pellets added according to the maintenance area of ​​the converter; After the converter taps out steel, the steel bar pellets are poured into the converter, and the tilting angle of the converter body is adjusted so that the steel bar pellets are laid flat on the maintenance position; The slag in the converter is completely submerged in the steel bar pellets spread on the maintenance position, and condensed simultaneously to obtain a protective layer of steel bar pellets wrapped with slag on the surface, so as to complete the large-surface maintenance of the converter.

2. The method according to claim 1, characterized in that The particle size of the steel bar cut particles is 100 mm to 500 mm.

3. The method according to claim 1, characterized in that The method of determining the amount of steel bar pellets to be added according to the maintenance area of ​​the converter includes: Relative to the maintenance area of ​​1 m2 of the large surface of the converter, the amount of steel bar pellets added is 0.27t to 0.67t.

4. The method according to claim 1, characterized in that: The condensation time is 1 min to 3 min.

5. The method according to claim 1, characterized in that The step of adjusting the tilting angle of the converter body so that the steel bar cut particles are laid flat on the maintenance position comprises: The large surface of the converter is evenly divided into three parts: upper, middle and lower. The converter is placed vertically with the horizontal plane as the reference angle, and the tilting angle of the converter body is adjusted so that the steel bar pellets are laid flat on the maintenance position; wherein, When maintaining the large surface of the converter, the tilting angle of the converter body is adjusted to 70° to 85°; When maintaining the middle part of the large surface of the converter, the tilting angle of the converter body is adjusted to 60° to 75°; When maintaining the lower portion of the large surface of the converter, the tilting angle of the converter body is adjusted to 45° to 60°.

6. The method according to claim 1, characterized in that The chemical composition of the steel bar pellets includes: C≤1.0wt%, Mn≤2.0wt%, P≤0.1wt%, S≤0.1wt%.

7. The method according to claim 1, characterized in that The method further comprises: The converter having a large converter surface with a protective layer of slag wrapped steel bar pellets is shaken to splash slag, and the position of the oxygen lance is controlled until the slag is splashed and poured out, so as to carry out the next furnace smelting.

8. The method according to claim 7, characterized in that The oxygen lance position is 1m to 1.5m.

9. The method according to claim 1, characterized in that: The total iron content of the converter slag is 14.5wt% to 18wt%, and the basicity of the converter slag is 2.8 to 3.5.

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