Converter tapping hole repairing material and preparation method thereof

Abstract

The present application relates to a kind of converter tapping hole repair material and preparation method, including repair layer, glaze layer, the repair layer is composed of the following raw materials: pretreated high-purity magnesia, carboxymethyl cellulose, binder;The pretreatment of high-purity magnesia: high-purity magnesia is soaked in magnesium sulfate heptahydrate aqueous solution for 24 hours or more, take out and dry at 100~110 ℃ temperature;Glaze layer is composed of the following raw materials: glass powder, potassium feldspar powder, quartz powder, SiC fine powder, chromium oxide green, water.The advantage is: converter tapping hole repair material according to the need characteristics of use position and steel plant, use high-purity magnesia soaked in magnesium sulfate heptahydrate aqueous solution as main raw material, improve the disintegration of material, shorten the replacement tapping hole time.Repair layer disintegration is excellent, the added carboxymethyl cellulose or clay and binder effectively improve the volume stability of repair agent at high temperature.

Description

Technical Field

[0001] This invention belongs to the field of converter steelmaking technology in the iron and steel metallurgical industry, and particularly relates to a repair material for converter tapping outlet and its preparation method. Background Technology

[0002] With the rapid development of infrastructure, steel companies are continuing to expand and upgrade their converters and build new medium and large-sized converters. During converter steelmaking, as the steel volume increases and tapping time lengthens, the tapping spout experiences excessively rapid internal diameter expansion due to the scouring effect of the molten steel, creating a weak point. To ensure normal production, the tapping spout must be repaired with repair materials after a period of scouring.

[0003] Currently, the repair material used for converter tapholes in the market is magnesium-calcium-iron alloy, designed to slow down the rate of taphole damage. However, the repair operation is difficult and the process can disrupt steel production. Furthermore, the presence of iron oxide in this material makes it prone to sintering, making it difficult to remove the original taphole during subsequent taphole replacements. With the accelerating pace of steel mill production and the reduced time required for taphole replacements, higher efficiency in taphole repair is demanded. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the purpose of this invention is to provide a converter tapping spout repair material and its preparation method, which solves the problems of severe sintering of existing repair materials, long tapping spout replacement time, and impact on the steelmaking rhythm of steel plants.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A repair material for a converter taphole includes a repair layer and a glaze layer, wherein the repair layer is composed of the following raw materials in parts by weight:

[0007] Pretreated high-purity magnesia: 3mm < particle size ≤ 5mm 20-30 parts; 1mm < particle size ≤ 3mm 30-35 parts; 0mm < particle size ≤ 1mm 20-25 parts; 200 mesh 15-20 parts;

[0008] 1 to 5 parts of carboxymethyl cellulose;

[0009] 2-4 parts of binder;

[0010] Pretreatment of high-purity magnesia: Soak high-purity magnesia in an aqueous solution of magnesium sulfate heptahydrate for more than 24 hours, then take it out and dry it at a temperature of 100-110℃.

[0011] The glaze layer is composed of the following raw materials in parts by weight:

[0012] 40-55 parts glass powder;

[0013] 15-25 parts of potassium feldspar powder;

[0014] 2-8 parts of quartz powder;

[0015] 3-10 parts of fine SiC powder;

[0016] 1-3 parts of chromium oxide green;

[0017] 30-75 parts water.

[0018] The binder is a mixture of resin and quartz powder.

[0019] The magnesium oxide content in the pretreated high-purity magnesia is >97%.

[0020] The particle size of the raw material for the glaze layer is less than 0.01 mm.

[0021] A method for preparing a repair material for a converter taphole includes:

[0022] 1) Preparation of the repair layer: The pretreated high-purity magnesia is crushed and sieved to obtain four particle sizes of 5-3mm, 3-1mm, 1-0mm and 200 mesh by weight for later use; carboxymethyl cellulose and binder are added to the high-purity magnesia by weight and dry-mixed until uniform.

[0023] 2) Preparation of glaze: Glass powder, potassium feldspar, quartz powder, SiC fine powder, chromium oxide green, and water are mixed and ground together;

[0024] 3) Apply a repair layer to the steel outlet body, and then spray a glaze layer on the surface of the repair layer;

[0025] 4) Dry at 90-120℃ for more than 10 hours, then raise the temperature to 220-260℃ and keep it at that temperature for more than 24 hours.

[0026] The repair layer thickness mentioned in step 3) is greater than the glaze layer thickness, and the glaze layer thickness is 1.5 to 4 mm.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1. The repair material for converter tapholes uses high-purity magnesia sand soaked in magnesium sulfate heptahydrate as the main raw material, based on the application location and the needs of the steel plant. This improves the material's disintegration properties and shortens the taphole replacement time.

[0029] 2. The repair layer has excellent disintegration properties. The added carboxymethyl cellulose or clay and binder effectively improve the volume stability of the repair agent at high temperatures.

[0030] 3. A glaze layer is sprayed onto the surface of the repair layer. This glaze seals the pores in the repair layer at high temperatures, significantly improving its overall integrity. Furthermore, as the temperature rises, components such as SiO2 and Cr2O3 in the glaze react with the magnesia, increasing the strength of the repair layer. This not only improves the overall integrity of the repair layer but also enhances its resistance to molten steel erosion. Because the glaze coating is relatively thin compared to the repair layer, it can be applied multiple times. This method of repairing the taphole significantly extends its lifespan. Moreover, when the taphole needs to be replaced, the thin glaze layer allows for easier disassembly, shortening the cleaning time of the scrap taphole and improving its replacement efficiency.

[0031] 4. The converter taphole repair material has excellent performance and its service life is more than 30 heats longer than that of commonly used converter taphole repair materials. Under the same smelting environment, the average service life can reach more than 200 heats. Detailed Implementation

[0032] The present invention will now be described in detail, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0033] Example 1

[0034] The preparation method of the repair material for the taphole of a converter includes the following steps:

[0035] 1. Preparation of the repair layer

[0036] 1) First, soak 97 high-purity magnesia in an aqueous solution of magnesium sulfate heptahydrate to allow the magnesium sulfate solution to penetrate into the pores of the 97 high-purity magnesia and improve its density.

[0037] 2) Dry the 97 high-purity ions that have been soaked for 24 hours at a temperature of 110°C for 6 hours.

[0038] 3) The dried high-purity magnesia is crushed and screened to obtain four particle sizes: 5-3 mm, 3-1 mm, 1-0 mm, and 200 mesh for later use; the magnesium oxide content of the high-purity magnesia is >97%.

[0039] 4) Ingredients: Prepare the ingredients according to the following weight ratio: 20 parts by weight of 5-3mm high-purity magnesia, 35 parts by weight of 3-1mm high-purity magnesia, 20 parts by weight of 1-0mm high-purity magnesia, 15 parts by weight of 200-mesh high-purity magnesia, 3 parts by weight of clay, and 3 parts by weight of binder. The binder is a mixture of resin and quartz powder in a 1:1 weight ratio.

[0040] 5) Dry mixing: Mix the ingredients obtained in step 5 until uniform.

[0041] 2. Preparation of glaze layer

[0042] Raw materials with a particle size of less than 0.01 mm are mixed and co-ground to form a support glaze. The raw materials are proportioned in the following weight ratios:

[0043] 42 parts glass powder, 18 parts potassium feldspar powder, 4 parts quartz powder, 5 parts SiC fine powder, 2 parts chromium oxide green, and 40 parts water.

[0044] 3. Apply a repair layer to the steel outlet body to ensure a smooth and uniform surface, and then spray a 2.5mm thick glaze layer on the repair layer surface. The repair layer should be at least 4mm thick.

[0045] Dry at 100℃ for 15 hours, then raise the temperature to 220-260℃ and keep it at that temperature for more than 24 hours.

[0046] Example 2

[0047] The preparation method of the repair material for the taphole of a converter includes the following steps:

[0048] 1. Preparation of the repair layer

[0049] 1) First, soak 97 high-purity magnesia in an aqueous solution of magnesium sulfate heptahydrate to allow the magnesium sulfate solution to penetrate into the pores of the 97 high-purity magnesia and improve its density.

[0050] 2) Dry the 97 high-purity ions that have been soaked for more than 24 hours at a drying temperature of 105℃.

[0051] 3) The dried high-purity magnesia is crushed and screened to obtain four particle sizes: 5-3 mm, 3-1 mm, 1-0 mm, and 200 mesh for later use; the magnesium oxide content of the high-purity magnesia is >97%.

[0052] 4) Ingredients: Prepare the following ingredients by weight ratio: 28 parts high-purity magnesia (5-3mm), 32 parts high-purity magnesia (3-1mm), 23 parts high-purity magnesia (1-0mm), 18 parts high-purity magnesia (200 mesh), 4 parts carboxymethyl cellulose, and 3 parts binder. The binder is a mixture of resin and quartz powder in a 2:1 weight ratio.

[0053] 5) Dry mixing: Mix the ingredients obtained in step 5 until uniform.

[0054] 2. Preparation of glaze layer

[0055] Raw materials with a particle size of less than 0.01 mm are mixed and co-ground to form a support glaze. The raw materials are proportioned in the following weight ratios:

[0056] 48 parts glass powder, 22 parts potassium feldspar powder, 6 parts quartz powder, 7 parts SiC fine powder, 2 parts chromium oxide green, and 60 parts water.

[0057] 3. Apply a repair layer to the steel outlet body to ensure a smooth and uniform surface, and then spray a 1.8mm thick glaze layer on the repair layer surface. The repair layer should be at least 3mm thick.

[0058] Dry at 110℃ for 12 hours, then raise the temperature to 230-250℃ and keep warm for more than 24 hours.

[0059] Example 3

[0060] The preparation method of the repair material for the taphole of a converter includes the following steps:

[0061] 1. Preparation of the repair layer

[0062] 1) First, soak 97 high-purity magnesia in an aqueous solution of magnesium sulfate heptahydrate to allow the magnesium sulfate solution to penetrate into the pores of the 97 high-purity magnesia and improve its density.

[0063] 2) Dry the high-purity water that has been soaked for more than 24 hours at a temperature of 105℃ for 10 hours.

[0064] 3) The dried high-purity magnesia is crushed and screened to obtain four particle sizes: 5-3 mm, 3-1 mm, 1-0 mm, and 200 mesh for later use; the magnesium oxide content of the high-purity magnesia is >97%.

[0065] 4) Batching: Batchute the following materials according to the following weight ratio: 28 parts by weight of 5-3mm high-purity magnesia, 30 parts by weight of 3-1mm high-purity magnesia, 22 parts by weight of 1-0mm high-purity magnesia, and 18 parts by weight of 200-mesh high-purity magnesia.

[0066] 4 parts by weight of clay, 3 parts by weight of binder. The binder is a mixture of resin and quartz powder in a weight ratio of 2:1.

[0067] 5) Dry mixing: Mix the ingredients obtained in step 5 until uniform.

[0068] 2. Preparation of glaze layer

[0069] Raw materials with a particle size of less than 0.01 mm are mixed and co-ground to form a support glaze. The raw materials are proportioned in the following weight ratios:

[0070] 52 parts glass powder, 21 parts potassium feldspar powder, 6 parts quartz powder, 8 parts SiC fine powder, 2 parts chromium oxide green, and 72 parts water.

[0071] 3. Apply a repair layer to the steel outlet body to ensure a smooth and uniform surface, and then spray a 3.2mm thick glaze layer on the repair layer surface. The repair layer should be at least 3mm thick.

[0072] Dry at 110℃ for 12 hours, then raise the temperature to 230-250℃ and keep warm for more than 24 hours.

[0073] Example 4

[0074] The preparation method of the repair material for the taphole of a converter includes the following steps:

[0075] 1. Preparation of the repair layer

[0076] 1) First, soak 97 high-purity magnesia in an aqueous solution of magnesium sulfate heptahydrate to allow the magnesium sulfate solution to penetrate into the pores of the 97 high-purity magnesia and improve its density.

[0077] 2) Dry the high-purity water that has been soaked for more than 24 hours at a temperature of 110℃ for 10 hours.

[0078] 3) The dried high-purity magnesia is crushed and screened to obtain four particle sizes: 5-3 mm, 3-1 mm, 1-0 mm, and 200 mesh for later use; the magnesium oxide content of the high-purity magnesia is >97%.

[0079] 4) Batching: Batchute the following materials according to the following weight ratio: 25 parts by weight of 5-3mm high-purity magnesia, 32 parts by weight of 3-1mm high-purity magnesia, 24 parts by weight of 1-0mm high-purity magnesia, and 15 parts by weight of 200-mesh high-purity magnesia.

[0080] The mixture consists of 3 parts by weight of carboxymethyl cellulose and 4 parts by weight of binder. The binder is a mixture of resin and quartz powder in a weight ratio of 2:1.

[0081] 5) Dry mixing: Mix the ingredients obtained in step 5 until uniform.

[0082] 2. Preparation of glaze layer

[0083] Raw materials with a particle size of less than 0.01 mm are mixed and co-ground to form a support glaze. The raw materials are proportioned in the following weight ratios:

[0084] 55 parts glass powder, 24 parts potassium feldspar powder, 7 parts quartz powder, 4 parts SiC fine powder, 1 part chromium oxide green, and 65 parts water.

[0085] 3. Apply a repair layer to the steel outlet body to ensure a smooth and uniform surface, and then spray a 2mm thick glaze layer on the repair layer surface. The repair layer should be at least 4mm thick.

[0086] Dry at 110℃ for 10 hours, then raise the temperature to 220-240℃ and keep warm for more than 24 hours.

Claims

1. A repair material for a converter taphole, characterized in that, It includes a repair layer and a glaze layer, wherein the repair layer is composed of the following raw materials in parts by weight: Pretreated high-purity magnesia: 3mm < particle size ≤ 5mm 20~30 parts; 1mm < particle size ≤ 3mm 30~35 parts; 0mm < particle size ≤ 1mm 20~25 parts; 200 mesh 15~20 parts; 1 to 5 parts of carboxymethyl cellulose or clay; 2-4 parts of binder; Pretreatment of high-purity magnesia: Soak high-purity magnesia in an aqueous solution of magnesium sulfate heptahydrate for more than 24 hours, then take it out and dry it at 100~110℃. The glaze layer is composed of the following raw materials in parts by weight: 40-55 parts glass powder; 15-25 parts of potassium feldspar powder; 2-8 parts quartz powder; 3-10 parts of fine SiC powder; 1-3 parts of chromium oxide green; 30-75 parts water; The binder is a mixture of resin and quartz powder; The pretreated high-purity magnesia contains >97% magnesium oxide. The particle size of the raw material for the glaze layer is below 0.01 mm; The repair layer is thicker than the glaze layer, and the glaze layer is 1.5~4mm thick.

2. The method for preparing a converter taphole repair material according to claim 1, characterized in that, include: 1) Preparation of the repair layer: The pretreated high-purity magnesia is crushed and sieved to obtain four particle sizes of 5~3mm, 3~1mm, 1~0mm and 200 mesh by weight for later use; carboxymethyl cellulose and binder are added to the high-purity magnesia by weight and dry-mixed until uniform. 2) Preparation of glaze: Glass powder, potassium feldspar, quartz powder, SiC fine powder, chromium oxide green, and water are mixed and ground together; 3) Apply a repair layer to the steel outlet body, and then spray a glaze layer on the surface of the repair layer; 4) Dry at 90~120℃ for more than 10 hours, then raise the temperature to 220~260℃ and keep warm for more than 24 hours.