Method for quickly repairing taphole mud sleeve on line

Abstract

The invention discloses a method for quickly repairing an iron notch mud sleeve on line. According to the method for rapidly repairing the taphole mud sleeve, only 1.5-2 hours are needed for repairing the mud sleeve, the consumed time is short, air reduction caused by repairing the mud sleeve in a furnace is avoided, the accidents of cracking, air reduction and plugging of the mud sleeve are thoroughly solved, the iron flux of one-time repairing is about 1.8 thousand tons, and good conditions are created for stable and smooth operation of a blast furnace. The iron notch mud sleeve is rapidly repaired on line through the method, continuous and stable production of a blast furnace can be guaranteed, the service life of the mud sleeve can be prolonged, the iron notch depth is stable, slag and iron are evenly discharged, and large-flow safety production accidents cannot be caused. According to the invention, the problems of iron notch mud sleeve damage, iron notch maintenance difficulty, iron notch depth instability, nonuniform slag iron discharge and blast furnace smooth operation damage in blast furnace continuous production are solved. Or the problems of mud rising, shallow taphole, large flow, equipment burning loss, personal safety endangering and the like are solved, and stable, smooth and excellent slag iron discharge and stable and smooth operation of the blast furnace are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of steel smelting, and in particular relates to a method for quickly repairing an iron mouth mud sleeve online. Background Art

[0002] The function of the iron mouth mud sleeve is to prevent the iron mouth frame from direct contact with slag and molten iron, thereby protecting the iron mouth frame. It also plays a role in protecting the iron mouth special-shaped bricks, allowing slag and iron to be discharged safely and smoothly and blocking the iron mouth without mud, so as to maintain an appropriate iron mouth depth, which is conducive to the formation and stability of mud bags.

[0003] The hydraulic mud cannon for plugging the iron mouth of a blast furnace needs to be in close contact with the iron mouth mud sleeve. The refractory mud is driven into the iron mouth by the hydraulic cannon under high pressure to seal the iron mouth, thus completing the process of plugging the iron mouth. Since the hydraulic mud cannon has a high pressure, it will cause a huge impact force on the iron mouth mud sleeve when it contacts the iron mouth mud sleeve. Therefore, in order to maintain the integrity of the iron mouth mud sleeve and the flatness of the contact surface, and to successfully complete the plugging operation of the hydraulic mud cannon, it is necessary to regularly repair the integrity of the iron mouth mud sleeve and the flatness of the contact surface between the mud sleeve and the hydraulic mud cannon.

[0004] The taphole mud sleeve is often washed and oxidized by high-temperature slag iron, and is easily damaged. Damage to the mud sleeve will cause blockage and mud leakage, resulting in the taphole being too shallow, the taphole passage being abnormal and irregular, and the taphole working state being abnormal. Not only can the slag iron not be discharged in time, resulting in abnormal blast furnace conditions, but it is also easy to cause production safety accidents such as large flow in front of the furnace. When the damage is serious, it will cause safety accidents such as reduced air blocking affecting the smooth operation of the blast furnace or failure of blocking, burning of equipment.

[0005] When the blast furnace is in continuous production, the pressure inside the furnace is high and there is gas leakage at the tap hole. The traditional method of online repairing the tap hole mud sleeve is to use full castables for repair, which has the following disadvantages: (1) The new material does not adhere to the old material, the structural stability is poor, there are many pores, the plugging and mud leakage increases, the tap hole depth is unstable, the slag and iron are not cleanly discharged, there is a lot of air blocking in the furnace, and the blast furnace is difficult to operate, resulting in an increase in the coke ratio of the blast furnace and a decrease in production. (2) There are more iron-tapping accidents in front of the furnace. During online repair, the tap hole gas leaks. The gas passes through the castable and forms many pores. If the pores are too large, they will crack when plugging, causing the plugging to fail, burning the mud gun, and requiring a wind stop to deal with the accident. (3) Full castables require more water and extend the baking time. In addition, the tap hole needs to be released continuously, which disrupts the tapping order and the production rhythm. (4) The mud sleeve has poor plasticity and will fall off in large pieces during use. The service life is short and the iron throughput is between 8,000 and 10,000 tons. Summary of the invention

[0006] In view of the above problems, the object of the present invention is to provide a method for quickly repairing the iron mouth mud sleeve online.

[0007] The object of the present invention is achieved by a method for online rapid repair of a taphole mud sleeve, which is achieved by the following steps: 1) Repair when the taphole mud sleeve is eroded by 200-300mm. First, use a pneumatic pick to clean the residual iron around the mud sleeve. Clean the bottom to the bottom edge of the mud sleeve. The cleaning depth is 300-400mm. Clean the bottom as clean as possible and clean the loose materials on the top. It is a trapezoidal shape. Blow away the residual ash with compressed air. Use a mud gun and a 10mm steel plate to fix the position. Fill the gap with mud sleeve mud. 2) The bottom of the mud sleeve is poured with castables, binder and water mixed in a ratio of 15-20:0.8-1:0.8-1. The castables flow freely and fill the bottom. The pouring height is 400-500mm and poured to the center line of the taphole. 3) Mix the mud jacket, castable, binder and water in a mass ratio of 1-2:8-10:0.8-2:0.4-0.6 to obtain a mixture, pour the mixture on the center line of the taphole, and then tamp it with a vibrating rod; 4) Finally, dry naturally for 5-10 minutes, then bake on low heat for 10-15 minutes, remove the cannon and demould, align the clay cannon and the opening machine, repair the socket, and bake on high heat for 10-30 minutes before putting it into use.

[0008] Working principle: When using the traditional method (all castables) for repair, the new material and the old material do not bond, and the iron mouth gas leaks, the contact surface is loose and has pores, and it is not dried. When plugging, the mud sleeve collapses and reduces the wind plugging, which affects the safe and stable production of the blast furnace. The main components of the mud sleeve are as follows: Al2O333%-45%, SiC20%-30%, C15%-20%, and the rest are bauxite and coke powder. The binder is water and asphalt. The main components of the castable are as follows: Al2O3>68%, SiC>12%; a small amount of coke powder in the aluminum mud sleeve has a breathable effect, and asphalt has a bonding effect. After the mud sleeve and castable are used together, the new material and the old material can be well bonded, and at the same time, the gas with large iron mouth pores can be blocked. A small amount of gas is conducive to penetrating the castable, which increases the density of the mud sleeve. The mixed castable requires less water, which is conducive to drying and saves time.

[0009] The bottom of the mud sleeve is cast with full castables, and Al2O3 is the skeleton. Since the bottom is immersed in slag iron, higher strength and thermal stability are required. The SiC expansion coefficient of the mud sleeve is low, which can prevent the castable from cracking during heating. The carbon powder of the mud sleeve can improve the plasticity. The casting mixture is above the center line of the iron mouth, which will not have any effect on the mud sleeve skeleton, and will effectively stop the gas leakage, and the mud sleeve will have better density and integrity.

[0010] The beneficial effects of the present invention are: 1. The method for quickly repairing the iron mouth mud sleeve of the present invention only takes 1.5-2 hours to repair the mud sleeve, which is relatively short. The furnace will not reduce air due to the mud sleeve repair, and the mud sleeve collapse, air reduction and blockage accidents are completely solved. The amount of iron passing through each repair is about 18,000 tons, creating good conditions for the stable and smooth operation of the blast furnace.

[0011] 2. The method of the invention is used to quickly repair the iron mouth mud sleeve online, which can ensure the continuous and stable production of the blast furnace, and can increase the service life of the mud sleeve. The iron mouth depth is stable, the slag and iron are discharged evenly, and no large flow leakage safety accidents will be caused.

[0012] 3. The present invention solves the problems of damaged iron mouth mud sleeve, difficult iron mouth maintenance, unstable iron mouth depth, uneven slag iron discharge, disrupting the smooth operation of the blast furnace, mud bubbling during plugging, shallow iron mouth, large flow, burning equipment, endangering personal safety, etc. during continuous production of the blast furnace, ensuring the "stable, smooth and excellent" slag iron discharge and stable and smooth operation of the blast furnace.

[0013] 4. Compared with the traditional method, the method of the present invention can increase the iron flow rate by 20,000 tons by online repair of the iron mouth mud sleeve at one time. The iron flow rate of the main channel is generally about 180,000 tons, and about 140,000 tons are repaired. After two repairs, the trench is stopped for maintenance. Due to gas leakage, the integrity of the mud sleeve is not good. During use, there are often gaps on the surface of the mud sleeve, and mud leakage increases when plugging the mouth. After adopting the method of the present invention, compared with the casting method using the traditional method, the iron mouth is better maintained, and the number of mud leakage from the plugging mouth is reduced from 50 times / month to less than 20 times / month. The labor intensity of the workers in front of the furnace is significantly reduced. The slag and iron discharge is more efficient, the blast furnace is more stable and smooth, and various indicators have reached new highs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the fixed formwork pouring diagram for the mud gun; Figure 2 The mud cover is poured and baked for 20 minutes before use. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention fall within the protection scope of the present invention.

[0016] The present invention provides a method for online rapid repair of iron mouth mud sleeve, which is implemented by the following steps: 1) Repair when the taphole mud sleeve is eroded by 200-300mm. First, use a pneumatic pick to clean the residual iron around the mud sleeve. Clean the bottom to the bottom edge of the mud sleeve. The cleaning depth is 300-400mm. Clean the bottom as clean as possible and clean the loose materials on the top. It is a trapezoidal shape. Blow away the residual ash with compressed air. Use a mud gun and a 10mm steel plate to fix the position. Fill the gap with mud sleeve mud. 2) The bottom of the mud sleeve is poured with castables, binder and water mixed in a ratio of 15-20:0.8-1:0.8-1. The castables flow freely and fill the bottom. The pouring height is 400-500mm and poured to the center line of the taphole. 3) Mix the mud jacket, castable, binder and water in a mass ratio of 1-2:8-10:0.8-2:0.4-0.6 to obtain a mixture, pour the mixture on the center line of the taphole, and then tamp it with a vibrating rod; 4) Finally, dry naturally for 5-10 minutes, then bake on low heat for 10-15 minutes, remove the cannon and demould, align the clay cannon and the opening machine, repair the socket, and bake on high heat for 10-30 minutes before putting it into use.

[0017] The binder is obtained by mixing water and asphalt in a ratio of 1:10-16.

[0018] The main components of the castable are as follows: Al2O3>68%, SiC>12%, and the rest is bauxite.

[0019] The following is Kunming Steel 2500m 3 The present invention is further described by taking No. 1 blast furnace as an example.

[0020] Example 1 Repairing No. 2 Iron Mouth Mud Sleeve On August 29, 2022, the No. 2 iron mouth mud sleeve with erosion of 300mm was repaired: 1) Clean the residual iron. Use a pneumatic pick to clean the residual iron around the mud sleeve. Clean the bottom to the bottom edge of the mud sleeve. The cleaning depth is 400mm. Clean the bottom as much as possible and clean the loose materials on the top. It is in a "trapezoidal" shape. Blow away the residual ash with compressed air. Use a mud gun and a 10mm steel plate to fix the position. Fill the gap with mud sleeve mud. 2) For pouring, mix 200kg of castable material (composition as follows: Al2O370%, SiC20%, the rest is bauxite), 10kg of binder and 10kg of water evenly and pour at a pouring height of 500mm to the center line of the taphole ( Figure 1 ); 3) Mix 20kg of mud casing mud (composition as follows: Al2O333.24%, SiC20.68%, C13.57%), 100kg of castable (composition as follows: Al2O370%, SiC20%, the rest is bauxite) and 11kg of binder (10kg of asphalt, 1kg of water), then add 5kg of water, stir evenly to obtain a mixture, pour the mixture on the center line of the taphole, and then tamp it with a vibrating rod; 4) Finally, dry naturally for 10 minutes, bake on low heat for 10 minutes, remove the gun and demould, align the mud gun and opening machine, repair the socket, bake on high heat for 20 minutes before putting into use ( Figure 2 ).

[0021] After adopting this method, not only did the No. 2 iron mouth mud sleeve not collapse, but the iron mouth gas leakage was also effectively controlled. The service life of the iron mouth mud sleeve was extended, and the number of mud leaks decreased month by month. The slag and iron discharge in front of the furnace became more efficient and smooth. The response indicators of No. 1 blast furnace reached new highs. This method was also applied to Kunming Iron and Steel No. 2 blast furnace with good results.

[0022] Example 2 Repairing No. 1 Iron Mouth Mud Sleeve On October 16, 2022, the No. 1 iron mouth mud sleeve with erosion of 200mm was repaired: 1) Clean the residual iron. Use a pneumatic pick to clean the residual iron around the mud sleeve. Clean from the bottom to the bottom edge of the mud sleeve. The cleaning depth is 300mm. The upper and lower parts are cleaned in a "trapezoidal" shape. Blow away the residual ash with compressed air. Use a mud gun and a 10mm steel plate to fix the position. Fill the gap with mud sleeve mud. 2) Pouring: 150kg of casting material (composition as follows: Al2O370%, SiC20%, the rest is bauxite), 8kg of binder and 8kg of water are mixed evenly and poured at the bottom. The pouring height is 500mm and pouring is to the center line of the taphole. 3) Mix 10kg of mud (composition: Al2O333.24%, SiC20.68%, C13.57%), 80kg of castable (composition: Al2O370%, SiC20%, the rest is bauxite) and 8.5kg of binder (8kg of asphalt, 0.5kg of water), add 4kg of water, mix well with a mixer to get a mixture, pour the mixture on the center line of the taphole, and tamp it with a vibrating rod; 4) Finally, dry naturally for 5 minutes, bake on low heat for 10 minutes, remove the gun and demoulding, align the mud gun and opening machine, repair the socket, bake on high heat for 10 minutes before putting into use.

[0023] After adopting this method, it took 90 minutes to repair the mud sleeve, and there was no mud when plugging the mouth. After the blast was withdrawn, the surface of the mud sleeve was checked to be flat and free of cracks. The iron flow rate of the iron mouth mud sleeve was 15,000 tons, the iron mouth depth was stable at 3.1-3.3 meters, the slag and iron were discharged smoothly, and the blast furnace ran stably and smoothly.

[0024] Comparative Example Before 2021, Kunming Iron and Steel No. 1 blast furnace had been using all-castable materials to repair the iron mouth mud sleeve. It took 3 to 4 hours to repair the mud sleeve. Each time the mud sleeve was repaired, another iron mouth was placed in a row. During the continuous placement, there was often a problem of holding back the wind and reducing the wind before iron production, which affected the output by about 100 tons. On December 18, 2021, the No. 2 iron mouth repaired the mud sleeve. It was repaired as usual and put into use in 3 hours and 40 minutes. The opening was normal, and 450 tons of iron was produced to plug the mouth. When plugging the mouth, the mud sleeve cracked and the mud gun pig mouth burned out. The wind was stopped for 2 hours, and the mud sleeve was remade and the gun mouth was replaced. The output was affected by 300 tons, and 20.8 tons of coke were added. During the treatment process, it was found that the lower part of the mud sleeve was good, and the upper part was cracked and loose, which was caused by online repair of gas leakage. The cracked part was repaired with mud sleeve mud and castables mixed evenly. The amount of iron through this repair was 13,000 tons.

[0025] On February 23, 2022, the No. 3 iron mouth mud sleeve was repaired with full castables. During the iron-out process, a small amount of molten iron was found on the upper edge of the mud sleeve, and the air was urgently reduced and blocked, and the protective cap was burned. The iron mouth mud sleeve was repaired again, and there was a crack on the upper edge of the mud sleeve and a gap on the lower edge of the mud gun.

[0026] On April 28, 2022, the No. 1 iron mouth mud sleeve was repaired with full castables. The iron mouth mud sleeve eroded 300m and was repaired with 300kg of castables. It took 4 hours and 20 minutes. After being put into use, the first furnace plugging was normal. The second furnace iron was tempered with mud. After the gun was withdrawn, it was checked that there was a small gap at the bottom edge of the mud sleeve. It was repaired with mud sleeve mud. During the third furnace iron plugging process, the bottom edge collapsed and the plugging failed. The molten iron invaded the gun body, the mud gun could not be withdrawn, and the gun body was burned. After the wind was stopped, oxygen was used to burn the bonding part. After the gun was withdrawn, it was found that the newly poured mud sleeve had completely fallen off. After re-cleaning, the profile was cast. The wind was stopped for 6 hours, affecting the production of 1,500 tons and adding 40 tons of coke. The entire mud gun body was burned and could not be repaired.

Claims

1. A method for online rapid repair of iron mouth mud sleeve, characterized in that: To do this, follow these steps: 1) Repair when the taphole mud sleeve is eroded by 200-300mm. First, use a pneumatic pick to clean the residual iron around the mud sleeve. Clean the bottom to the bottom edge of the mud sleeve. The cleaning depth is 300-400mm. Clean the bottom as clean as possible and clean the loose materials on the top. It is a trapezoidal shape. Blow away the residual ash with compressed air. Use a mud gun and a 10mm steel plate to fix the position. Fill the gap with mud sleeve mud. 2) The bottom of the mud sleeve is poured with castables, binder and water mixed in a ratio of 15-20:0.8-1:0.8-1. The castables flow freely and fill the bottom. The pouring height is 400-500mm and poured to the center line of the taphole. 3) Mix the mud jacket, castable, binder and water in a mass ratio of 1-2:8-10:0.8-2:0.4-0.6 to obtain a mixture, pour the mixture on the center line of the taphole, and then tamp it with a vibrating rod; 4) Finally, dry naturally for 5-10 minutes, then bake on low heat for 10-15 minutes, remove the gun and demoulding, align the mud gun and opening machine, repair the socket, bake on high heat for 10-30 minutes before putting into use.

2. The method for online rapid repair of iron mouth mud sleeve according to claim 1 is characterized in that: The binder is obtained by mixing water and asphalt in a ratio of 1:10-16.

3. The method for online rapid repair of iron mouth mud sleeve according to claim 1 is characterized in that: The main components of the castable are as follows: Al2O3>68%, SiC>12%, and the rest is bauxite.

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