Online treatment method for blast furnace taphole splashing

Abstract

The invention relates to the technical field of blast furnace smelting and iron notch maintenance, and discloses an online treatment method for blast furnace iron notch splashing, which comprises the following steps of: filling an iron notch balling gap with a self-flowing repair material, grouting a hot surface of a blast furnace hearth, and selecting anhydrous stemming for blocking an iron notch with the Marshall value of more than 600KPa. According to the method, the combination of filling the gap of the iron notch channel with the self-flowing repairing material and filling the gap of the cooling wall and the carbon brick with the grouting is adopted, so that the phenomenon of coal gas blowby of the iron notch is effectively eradicated, meanwhile, the Marshall value of the anhydrous stemming of the blast furnace is increased to 600 KPa or above, the working condition of the iron notch is improved, and slag iron is bundled and discharged smoothly. The blast furnace with the taphole treated by the method provided by the invention can accelerate the time of reaching the standard and reaching the production.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace smelting and iron mouth maintenance, and in particular to an online treatment method for blast furnace iron mouth splashing. Background Art

[0002] The iron mouth of a blast furnace is located at the lower edge of the furnace. It is mainly composed of an iron mouth frame, a protective plate, a brick sleeve, a mud sleeve, an iron flow channel and a mud bag. Its working environment is harsh and it is eroded and washed by high-temperature slag for a long time. After the overhaul or the start-up of a newly built blast furnace, most blast furnaces will experience iron mouth splashing. The main reason is that there are many types of refractory materials in the iron mouth area. After the blast furnace is started, as the temperature rises, various refractory materials gradually shrink and have different shrinkage coefficients. The steel structure expands and contracts with heat, causing gaps between the iron mouth combination bricks and carbon bricks, and between the carbon bricks and the cooling wall. Then, coal gas is generated from the tuyere area and rushes along the hot surface to the iron mouth channel. During the iron-out process, the molten iron is accompanied by coal gas, resulting in splashing. Iron mouth splashing brings a large amount of smoke and slag, which worsens the working environment of the iron-out area, affects the discharge of iron mouth slag and the normal production of the blast furnace, and in severe cases, even causes the iron mouth to be blocked and the blast furnace is forced to stop. In addition, during the blast furnace production process, the brick lining in the tapping area is repeatedly operated during the iron-making process. The tapping machine drilling and mud gun plugging have a great impact on the brick lining, causing gaps in the carbon brick lining. In abnormal furnace conditions, the tapping oxygen gun is used to increase the temperature, which will cause damage to the brick lining in some areas and form a gas channel. At the same time, due to the need to adjust the furnace conditions, the tapping angle and the tapping machine angle are adjusted at any time, and the drill rod and drill bit form new impacts, and the carbon brick lining will also have gaps to leak gas. During operation, if the cooling equipment leaks and is not handled in time, the cooling water and high-temperature slag form water vapor, which contacts the carbon bricks to oxidize and corrode the brick lining, and also causes gaps to leak gas. At the same time, harmful metals in the raw materials entering the furnace, such as alkali metals and zinc, will penetrate into the brick joints and expand due to heat, causing gaps in the brick lining.

[0003] In summary, the primary task is to fundamentally solve the problem of iron mouth splashing and eliminate the gaps in the brick lining. At present, the main method for dealing with blast furnace iron mouth splashing in China is to use the blast furnace wind stop opportunity to open holes in the furnace shell near the iron mouth, and use special grouting equipment for grouting treatment. However, due to the large number of gaps generated, the slurry pressed in is not full, and the effect of grouting treatment is not obvious. In addition, the grouting treatment requires opening holes, which prolongs the blast furnace wind stop time and affects the normal production of the blast furnace. Summary of the invention

[0004] In view of the above-mentioned shortcomings, the purpose of the present invention is to provide a high-efficiency, low-cost method for online treatment of blast furnace iron mouth splashing, which is used to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions.

[0006] An online treatment method for blast furnace iron mouth splashing, comprising step A of filling the gap of the iron mouth mud bag with a self-flowing repair material, step B of grouting the hot surface of the blast furnace hearth, and selecting the waterless taphole mud for plugging the iron mouth with a Maxwell value of more than 600KPa;

[0007] The operation method of step A is as follows: the tapping machine drills a hole in the tapping hole of the blast furnace, the drilling depth of the hole is 50% of the length of the tapping hole, and then the self-flowing repair material is pushed into the drilled hole by a mud gun and the pressure is stabilized until the self-flowing repair material is solidified, and then the mud gun is withdrawn to tap the iron normally;

[0008] The operation method of step B is: pouring the grouting material into the grouting holes on the furnace until each grouting hole is full of grouting material after grouting.

[0009] Furthermore, the step A is performed using the gaps of cross-iron tapping in the blast furnace, and the step B is performed during normal production of the blast furnace, thereby avoiding occupying the blast furnace wind stop opportunity and achieving online control of blast furnace iron mouth splashing.

[0010] Furthermore, in step A, the time for the mud gun to push the self-flowing repair material into the borehole and maintain pressure is 20-30 minutes, which depends on the curing time of the self-flowing repair material.

[0011] Furthermore, the self-flowing repair material is BC-60R, a product of Shanghai Baojiuhe Refractory Materials Co., Ltd.

[0012] Furthermore, the indicators of the self-flowing repair material after curing are Al2O3≥60%, SiC≥10%, and free C≥5%.

[0013] Furthermore, the grouting material is selected from rare earth composite high thermal conductivity press-in material.

[0014] Furthermore, the indicators of the rare earth composite high thermal conductivity press-in material are free C ≥ 35%, thermal conductivity ≥ 9W / mk, flow value ≥ 100%, particle size ≤ 1mm, and bulk density ≥ 1.1g / cm 3 , curing time 24h.

[0015] Furthermore, in step B, an impact drill is used to clean the grouting holes before grouting.

[0016] Compared with the prior art, the present invention adopts a combination of self-flowing repairing materials to fill the gaps in the iron mouth channel and grouting to fill the gaps between the cooling wall and the carbon bricks, which effectively prevents the phenomenon of gas leakage from the iron mouth. At the same time, the Maxwell value of anhydrous taphole mud of the blast furnace is increased to above 600KPa, thereby improving the working condition of the iron mouth, bundling the slag and iron, and ensuring smooth discharge.

[0017] The method of the present invention has the following beneficial effects:

[0018] (1) The method of the present invention can be used to simply, quickly and efficiently control the splashing phenomenon at the iron mouth of a blast furnace;

[0019] (2) The burning phenomenon of equipment and facilities in front of the furnace is improved, and the equipment is effectively protected;

[0020] (3) Reduce production costs and improve iron quality;

[0021] (4) It reduces the labor intensity in front of the furnace, shortens the processing time in front of the furnace, and ensures that the blast furnace taps iron on time;

[0022] (5) The tapping time is optimized, and the tapping is smooth, ensuring the long-term stability of the blast furnace;

[0023] (6) Reduced pollution and improved the environment. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example: Blast furnace size 1250m 3 The tap hole is located on the furnace shell. The tap hole is a pipe made of bricks. The pipe is filled with castables. When tapping iron, the pipe is opened and iron is tapped through the tapping channel. The blast furnace was opened on December 9, 2022. After tapping iron, it was found that there was a splashing problem at the tap hole, so the tap hole was maintained.

[0026] (1) Use self-flowing repair material (BC-60R, a product of Shanghai Baojiuhe Refractory Materials Co., Ltd.) to treat iron mouth splashing, and determine the indicators: Al2O3 ≥ 60%, SiC ≥ 10%, FC ≥ 5%.

[0027] During normal production, the iron mouth channel is drilled to half the normal depth by utilizing the gap of cross-iron tapping of the blast furnace. The self-flowing repair material is driven into the iron mouth channel by the pressure of the mud gun and the pressure is maintained at a constant level for 30 minutes, so that the self-flowing repair material fills the gap of the iron mouth mud bag and is sintered and solidified. After maintaining the pressure for 30 minutes, the gun is withdrawn and the iron mouth is opened according to the normal iron tapping rhythm. After the iron mouth is blown, the normal amount of mud is injected into the iron mouth immediately to block the iron mouth normally, and another iron mouth is opened. When the next round of iron tapping occurs, iron is tapped in normal mode. Repeat this operation to repair and control iron mouth splashing.

[0028] (2) Grout the hot surface of the furnace. Index requirements: rare earth composite high thermal conductivity press-in material (non-curing), TC ≥ 35%, thermal conductivity ≥ 9W / mk, flow value ≥ 100%, particle size ≤ 1mm, volume density ≥ 1.1g / cm 3 , rare earth composite high thermal conductivity press-fit material (curing), TC ≥ 30%, flow value ≥ 100%, particle size ≤ 1mm, bulk density ≥ 1.1g / cm 3 , curing time 24h.

[0029] The specific method is: under normal production of the blast furnace, the gap between the cooling wall and the carbon bricks is filled with grouting, and after grouting, the grouting holes are full of slurry, and there is no gas leakage from the grouting holes around the grouting holes, so that there is no gas leakage from the iron mouth, and the iron mouth splashing control effect is achieved.

[0030] (3) The summer value of the anhydrous taphole mud of the blast furnace was increased from 500KPa to over 600KPa, which improved the working condition of the iron mouth, bundled the slag and iron, and made the discharge smooth.

[0031] The taphole repaired through the above steps effectively controls the splashing phenomenon at the taphole, ensuring the punctual tapping time of the blast furnace; improves the burning phenomenon of equipment and facilities in front of the furnace, and the equipment is effectively protected; reduces production costs and improves the tapping quality; optimizes the tapping time, ensures smooth tapping, and ensures long-term stability of the blast furnace; reduces pollution and improves the environment.

[0032] In summary, the blast furnace after the taphole is treated by the present invention can accelerate the time for it to reach the standard and reach full production.

[0033] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An online treatment method for blast furnace iron mouth splashing, characterized in that: The method comprises the steps of filling the gap of the iron mouth mud bag with a self-flowing repair material A, grouting the hot surface of the blast furnace hearth B, and selecting the Marshall value of the waterless taphole mud for plugging the iron mouth to be above 600KPa; The operation method of step A is as follows: the tapping machine drills a hole in the tapping hole of the blast furnace, the drilling depth of the hole is 50% of the length of the tapping hole, and then the self-flowing repair material is pushed into the drilled hole by a mud gun and the pressure is stabilized until the self-flowing repair material is solidified, and then the mud gun is withdrawn to tap the iron normally; The operation method of step B is: pouring the grouting material into the grouting holes on the furnace until each grouting hole is full of grouting material after grouting.

2. The online treatment method for blast furnace iron mouth splashing according to claim 1, characterized in that: The step A is performed using the gaps of cross-iron tapping in the blast furnace, and the step B is performed under normal production conditions of the blast furnace.

3. The online treatment method for blast furnace iron mouth splashing according to claim 1, characterized in that: In step A, the mud gun pushes the self-flowing repair material into the borehole and maintains the pressure for 20-30 minutes.

4. The online treatment method for blast furnace iron mouth splashing according to claim 1 is characterized in that: The self-flowing repair material is BC-60R, a product of Shanghai Baojiuhe Refractory Materials Co., Ltd.

5. The online treatment method for blast furnace iron mouth splashing according to claim 1 is characterized in that: The indicators of the self-flowing repair material after solidification are Al2O3≥60%, SiC≥10%, and free C≥5%.

6. The online treatment method for blast furnace iron mouth splashing according to claim 1, characterized in that: The grouting material is selected from rare earth composite high thermal conductivity press-in material.

7. The online treatment method for blast furnace iron mouth splashing according to claim 6 is characterized in that: The indicators of the rare earth composite high thermal conductivity press-in material are free C ≥ 35%, thermal conductivity ≥ 9W / mk, flow value ≥ 100%, particle size ≤ 1mm, and bulk density ≥ 1.1g / cm 3 , curing time 24h.

8. The online treatment method for blast furnace iron mouth splashing according to claim 1, characterized in that: In step B, a percussion drill is used to clean the grouting hole before grouting.