A method for online repair of blast furnace gooseneck tube

Abstract

The present invention proposes a method for online repairing a blast furnace gooseneck. By spraying chrome corundum slurry with specific properties and combining it with a cart-type high-pressure airless spraying kit, rapid and efficient repair of refractory cracks in the gooseneck can be achieved, avoiding production interruption and cost increase caused by replacing the gooseneck, and having broad application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of blast furnaces, and in particular relates to a method for online repairing a blast furnace gooseneck. Background Art

[0002] In the blast furnace smelting process, the gooseneck pipe is a key component connecting the blast furnace and the hot blast stove. It is subjected to high temperature, high pressure and scouring for a long time, which is prone to refractory cracks and affects the stable operation of the blast furnace. Traditional repair methods often require the blast furnace to be shut down and the gooseneck pipe to be replaced, which is not only time-consuming and labor-intensive, but also increases the cost of spare parts and production interruption time. Therefore, developing a method for online repair of gooseneck pipes is of great significance to improving blast furnace operating efficiency and reducing production costs. Summary of the invention

[0003] Aiming at the problem that the prior art replaces the gooseneck by stopping the wind, which is time-consuming, labor-intensive and increases the cost, the present invention proposes a method for online repairing the gooseneck of a blast furnace.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for online repairing of a blast furnace gooseneck tube comprises the following steps:

[0006] S1: Dilute the chrome corundum slurry with water to a fluidity state suitable for spraying;

[0007] S2: Load the diluted chrome corundum slurry into the container of the trolley-type high-pressure airless spraying set. The output flow of the equipment for each cycle is not less than 180CC, and the working pressure is greater than 25MPa, ensuring that the slurry can be sprayed evenly and efficiently on the inner wall of the gooseneck tube;

[0008] S3: According to the blast furnace maintenance plan, after the temperature of the gooseneck tube drops to a safe range, open the gland at the rear end of the gooseneck tube and use a cart-type high-pressure airless spraying set machine to spray the inner wall of the gooseneck tube for the first time;

[0009] S4: After the first spraying, wait for 3-5 minutes for the mud to solidify initially, and then spray again to enhance the repair effect.

[0010] Preferably, the chemical composition of the chrome corundum slurry needs to meet the following requirements: aluminum oxide content ≥ 86%, titanium dioxide content ≥ 0.10%, and chromium trioxide content ≥ 3.5%.

[0011] Preferably, the performance indicators of the chrome corundum slurry need to meet the following requirements: after drying at 110°C, the room temperature flexural bonding strength is ≥2.0MPa, after sintering at 1500°C×3h, the room temperature flexural bonding strength is ≥6.0MPa, the 0.2MPa load softening temperature is ≥1600°C, after sintering at 1500°C×3h, the heating permanent line change rate is -5~+1%, and the bonding time is 1~3 minutes.

[0012] Preferably, the particle size distribution of the chrome corundum slurry needs to meet the following requirements: particle size <1.0 mm content 100%, particle size >0.5 mm content ≤1%, particle size <0.075 mm content ≥40%.

[0013] Compared with the prior art, the advantages and positive effects of the present invention are:

[0014] The invention realizes the rapid online repair of cracks in the refractory material of the blast furnace gooseneck tube by spraying chrome corundum slurry with specific properties, thus avoiding production interruption and cost increase caused by stopping the machine to replace the gooseneck tube.

[0015] The use of a cart-type high-pressure airless spraying set ensures uniform spraying of the mud and efficient repair, improving the quality and efficiency of the repair;

[0016] The spraying method of the present invention is simple to operate and easy to implement, is suitable for online repair of various blast furnace gooseneck tubes, and has wide popularization and application value. DETAILED DESCRIPTION

[0017] In order to better understand the present invention, the following is a detailed description with reference to the embodiments.

[0018] Example

[0019] This embodiment provides a method for online repairing a blast furnace gooseneck tube, and the steps of the repair method are as follows:

[0020] S1: Dilute the chrome corundum slurry with water to a fluidity state suitable for spraying;

[0021] S2: Load the diluted chrome corundum slurry into the container of the trolley-type high-pressure airless spraying set. The output flow of the equipment for each cycle is not less than 180CC, and the working pressure is greater than 25MPa, ensuring that the slurry can be sprayed evenly and efficiently on the inner wall of the gooseneck tube;

[0022] S3: According to the blast furnace maintenance plan, after the temperature of the gooseneck tube drops to a safe range, open the gland at the rear end of the gooseneck tube and use a cart-type high-pressure airless spraying set machine to spray the inner wall of the gooseneck tube for the first time;

[0023] S4: After the first spraying, wait for 3-5 minutes for the mud to solidify initially, and then spray again to enhance the repair effect. After the spraying is completed, the gooseneck can be restored without replacing the gooseneck, thus saving spare parts costs and replacement time.

[0024] The chemical composition of the chrome corundum slurry used must meet the following requirements: Alumina (Al 2 O 3 ) content ≥86%, titanium dioxide (TiO 2 ) content ≥ 0.10%, chromium trioxide (Cr 2 O 3 ) content ≥3.5%.

[0025] The performance indicators of the mud must meet the following requirements: room temperature flexural bond strength (after drying at 110°C) ≥ 2.0MPa, room temperature flexural bond strength (after burning at 1500°C×3h) ≥ 6.0MPa, 0.2MPa load softening temperature ≥ 1600°C, heating permanent linear change rate (after burning at 1500°C×3h) of -5~+1%, and bonding time of 1~3 minutes.

[0026] The particle size distribution of the mud must meet the following requirements: particle size <1.0mm content 100%, particle size >0.5mm content ≤1%, particle size <0.075mm content ≥40%.

[0027] The preparation method of chrome corundum slurry is as follows:

[0028] The electric fusion method uses industrial alumina micropowder and chromium oxide micropowder as raw materials. After being fully stirred and evenly mixed, the raw materials are melted by electric fusion at high temperature; then the raw materials are melted by the high temperature of plasma and quickly cooled to form fine powder, thus making chrome corundum slurry.

[0029] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for online repair of a blast furnace gooseneck, characterized in that: The following steps are included: S1: Dilute the chrome corundum slurry with water to a fluidity state suitable for spraying; S2: Load the diluted chrome corundum slurry into the container of the trolley-type high-pressure airless spraying set. The output flow of the equipment for each cycle is not less than 180CC, and the working pressure is greater than 25MPa, ensuring that the slurry can be sprayed evenly and efficiently on the inner wall of the gooseneck tube; S3: According to the blast furnace maintenance plan, after the temperature of the gooseneck tube drops to a safe range, open the gland at the rear end of the gooseneck tube and use a cart-type high-pressure airless spraying kit to spray the inner wall of the gooseneck tube for the first time; S4: After the first spraying, wait for 3-5 minutes for the mud to solidify initially, and then spray again to enhance the repair effect.

2. The method for online repairing of blast furnace gooseneck according to claim 1, characterized in that: The chemical composition of the chrome corundum slurry must meet the following requirements: aluminum oxide content ≥86%, titanium dioxide content ≥0.10%, and chromium trioxide content ≥3.5%.

3. The method for online repairing of blast furnace gooseneck according to claim 2, characterized in that: The performance indicators of the chrome corundum mud must meet the following requirements: after drying at 110°C, the room temperature flexural bonding strength is ≥2.0MPa; after sintering at 1500°C×3h, the room temperature flexural bonding strength is ≥6.0MPa; the 0.2MPa load softening temperature is ≥1600°C; after sintering at 1500°C×3h, the heating permanent line change rate is -5~+1%; and the bonding time is 1~3 minutes.

4. The method for online repairing of blast furnace gooseneck according to claim 3 is characterized in that: The particle size distribution of the chrome corundum slurry must meet the following requirements: particle size <1.0 mm content 100%, particle size >0.5 mm content ≤1%, particle size <0.075 mm content ≥40%.