Method for preparing torpedo can mouth coating material by using recycled high-aluminum material

Abstract

The application relates to the technical field of industry, and discloses a method for preparing torpedo tank mouth coating material by using recycled high-aluminum materials, which comprises the following steps: waste material recycling, raw material crushing, dry mixing, sampling detection and packaging. The waste old high-aluminum materials are classified, selected and component detected through the waste material recycling step, and are adjusted according to the alumina content, so that the component stability of the recycled materials as the core raw materials is ensured, and the recycled high-aluminum materials replace part of the primary high-aluminum raw materials to prepare the coating material, the solid waste resources of the waste old high-aluminum bricks and the waste old high-aluminum castable can be efficiently utilized, the production cost of the torpedo tank mouth coating material is reduced, the consumption of non-renewable mineral resources is reduced, and the environmental pollution caused by the accumulation of the solid waste is reduced.

Description

Technical Field

[0001] This invention relates to the field of industrial technology, specifically to a method for preparing a torpedo can mouth coating material using recycled high-alumina materials. Background Technology

[0002] High-alumina refractory material is a refractory material formed by high-alumina bauxite through high-temperature calcination. Its main minerals are gibbsite and high-alumina silica. It has the characteristics of high alumina and low iron, and is resistant to high temperature and corrosion. It is widely used in electric furnace tops, blast furnaces and hot blast stoves in the metallurgical industry, and is also used in the manufacture of refractory bricks and anti-corrosion materials.

[0003] Currently, due to the extremely harsh working environment of torpedo can mouths, which are subjected to long-term erosion by molten iron, slag alkali, and frequent temperature fluctuations, the refractory materials at the can mouth area are damaged quickly and require frequent repairs. Existing torpedo can mouth coatings are mostly made from high-alumina raw materials such as high-quality bauxite and corundum, resulting in high raw material costs and the consumption of a large amount of non-renewable mineral resources. At the same time, the solid waste of a large amount of waste high-alumina bricks and waste high-alumina castables generated by steel enterprises is not effectively utilized, which not only occupies land but also easily causes environmental pollution. Furthermore, when using recycled high-alumina materials to prepare coatings, the complex sources and large fluctuations in composition of recycled materials make it impossible to accurately control the impurity content and particle size distribution of the recycled materials. This leads to unstable construction performance and high-temperature physical properties of the prepared coatings that fail to meet the requirements. Moreover, the existing technology lacks systematic pretreatment processes and formulation adaptation methods for recycled high-alumina materials, which can cause the coatings to peel off, flake off, or have a significantly shortened service life when used in torpedo can mouths, affecting the normal operating efficiency and maintenance costs of torpedo cans.

[0004] Therefore, a method for preparing torpedo can mouth coating material using recycled high-alumina materials is proposed to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing torpedo canister coating material using recycled high-alumina materials, which solves the problem mentioned in the background art of the inability to accurately control the impurity content and particle size distribution of recycled materials.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a torpedo can mouth coating material using recycled high-alumina material, the method comprising the following steps: Step 1: Waste recycling. High-alumina waste materials are sorted and recycled, manually picked, and their composition is tested to ensure that the alumina content in the recycled materials is greater than 80%. Step 2: Raw material crushing. The waste high-alumina material selected in Step 1 is conveyed to the crusher and crushed and screened into three particle size grades: 5-3mm, 3-1mm, and 1-0.074mm. Step 3: Dry mixing. By weight, take 62-80 parts of the recycled material obtained in Step 2, 0-8 parts of kyanite with a particle size of 1-0 mm, 0-15 parts of white clay with a particle size of 200 mesh, 6-11 parts of grade IV fine powder with a particle size of 200 mesh, 10-15 parts of 625 cement with a particle size of 200 mesh, 0-0.3 parts of water-reducing agent, and 0-0.5 parts of binder. First, add the recycled material and kyanite to the mixer and mix for 3-5 minutes. Then add the white clay, grade IV fine powder, and 625 cement and mix for 5-8 minutes. Finally, add the water-reducing agent and binder and mix for 2-4 minutes to obtain the mixture. Step 4: Sampling and testing. Take the mixture obtained in Step 3, add water and stir, then vibrate and mold it. After demolding and drying, perform heat treatment and test the physical properties. Step 5: Packaging. Pack the mixture obtained in Step 3 and store it in a dry and cool environment.

[0007] Preferably, in step one, the waste high-alumina material includes one of waste high-alumina bricks and waste high-alumina castables. During manual sorting, slag shells, metal impurities and low-alumina impurities are removed. The alumina content is determined by X-ray fluorescence spectrometry. When the alumina content is less than 80%, it is mixed with high-alumina waste in a ratio of not less than 80%.

[0008] Preferably, in step two, the crusher includes a jaw crusher, an impact crusher, and a double roll crusher. The crushed material is sequentially screened through a square hole screen, wherein the 5-3mm particle size accounts for 20%-40%, the 3-1mm particle size accounts for 15%-35%, and the 1-0.074mm particle size accounts for 25%-55%. The recovered material of each particle size after screening is stored in a closed silo with a moisture content of no more than 0.5%.

[0009] Preferably, in step three, the kyanite contains more than 50% alumina, more than 40% silica, and has a loss on ignition of no more than 1.5%. Before use, it is crushed to 1-0 mm by a jaw crusher. After crushing, the proportion of particles larger than 1 mm in the kyanite is no more than 3%. The white clay contains more than 30% alumina, more than 50% silica, and has a proportion of particles smaller than 0.074 mm of no less than 95%. Before use, it is dried at 105℃±5℃ for 2 hours and then cooled to room temperature before use.

[0010] Preferably, in step three, the alumina content of the fourth-grade fine powder is greater than 50%, the silica content is greater than 30%, the iron oxide content is not higher than 2.5%, and the proportion of particles with a particle size of less than 0.074 mm is not less than 98%. The alumina content of the 625 cement is greater than 50%, the calcium oxide content is not higher than 35%, the specific surface area is not less than 350 m² / kg, the initial setting time is not less than 45 min, the final setting time is not higher than 600 min, and it is sealed and stored before use for no more than 30 days.

[0011] Preferably, in step three, the water-reducing agent is one of polycarboxylate-based high-performance water-reducing agent, naphthalene-based water-reducing agent, or lignin sulfonate water-reducing agent, with a water reduction rate of not less than 20% and an air content of not more than 3%. The binder is one of silica sol, aluminum dihydrogen phosphate, or modified starch ether, wherein the silica sol contains 20%-30% silica and has a pH value of 8-10, the aluminum dihydrogen phosphate contains not less than 30% phosphorus pentoxide and not less than 10% aluminum oxide.

[0012] Preferably, in step three, the dry mixing process uses a twin-shaft paddle mixer with a mixing shaft speed of 300-500 r / min. During mixing, the temperature inside the mixer is controlled at 15-35℃, and the relative humidity is not higher than 60%. Before adding the water-reducing agent and binder, the temperature of the mixture is adjusted to 20-25℃. During the mixing process, samples are taken every 2 minutes to test the mixing uniformity. Mixing is stopped when the coefficient of variation does not exceed 5%.

[0013] Preferably, in step four, the water-to-material ratio is 0.14-0.16 when adding water and stirring. A planetary mixer is used for stirring at a speed of 60-100 r / min for 3-5 min. Vibration molding is performed using a vibrating table at a frequency of 50-60 Hz for 30-60 s. The size of the molded specimen is 40 mm × 40 mm × 160 mm. After demolding, it is dried at 110℃ ± 5℃ for 24 h and then heat-treated at 1400℃ ± 10℃ for 3 h. The heating rate during heat treatment does not exceed 5℃ / min.

[0014] Preferably, in step four, the physical indicators tested include bulk density, apparent porosity, room temperature compressive strength, and flexural strength at 1400℃ for 3 hours. The qualified standards are: bulk density not less than 2.2 g / cm³, apparent porosity not more than 22%, compressive strength at 110℃ for 24 hours not less than 15 MPa, and flexural strength at 1400℃ for 3 hours not less than 18 MPa.

[0015] Preferably, in step five, moisture-proof composite woven bags are used for packaging, with each bag having a net weight of 25kg±0.2kg. The temperature of the mixed material during packaging should not exceed 40℃. After packaging, the bag openings are sealed. A moisture-proof layer is laid on the floor of the storage warehouse. The stacking height should not exceed 10 layers, and the stack spacing should not be less than 0.5m. The temperature inside the warehouse is controlled at 5-35℃, the relative humidity should not exceed 60%, and the storage period should not exceed 90 days. A re-inspection is carried out before leaving the warehouse. The re-inspection items include moisture content and construction performance. If the moisture content is greater than 0.8%, it needs to be dried again.

[0016] Compared with the prior art, the present invention provides a method for preparing torpedo can mouth coating material using recycled high-alumina material, which has the following beneficial effects: 1. In this invention, waste high-alumina materials are classified, sorted, and tested for components through a waste recycling step, and then adjusted according to the alumina content to ensure the stability of the composition of the recycled material as the core raw material. At the same time, the recycled high-alumina material replaces part of the original high-alumina raw material in the preparation of coating material. This can efficiently utilize the solid waste resources of waste high-alumina bricks and waste high-alumina castables, ensure that the production cost of torpedo can mouth coating material is reduced, reduce the consumption of non-renewable mineral resources, and reduce environmental pollution caused by solid waste accumulation.

[0017] 2. In this invention, the recycled material is subjected to multi-stage screening through the raw material crushing step, and the proportion and moisture content of each particle size class are controlled in real time. This enables the preparation system to reduce the fluctuation of particle size distribution caused by the complex source of the recycled material. Moreover, when abnormal deviations occur in the particle size distribution of the mixture, the particle size distribution can be corrected in real time by adjusting the crushing and screening parameters. This ensures that the particle size distribution of the recycled material can accurately match the construction and density requirements of the coating material, thus guaranteeing the uniformity of the coating material's construction performance and the stability of its high-temperature structure.

[0018] 3. In this invention, during the mixture preparation stage, by limiting the raw material indicators of kyanite, white clay, grade IV fine powder, 625 cement, water-reducing agent, and binder, and combining the mixing parameters and uniformity control of the dry mixing process, the homogenization and dispersion of multiple components are achieved according to the characteristics of different raw materials. This enables the system to adapt the formula and process to different batches of recycled high-alumina materials, reducing the risk of the coating material peeling or flaking off after high-temperature use, and improving the service life of the torpedo can mouth coating material and the operating efficiency of the torpedo can. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: A method for preparing a torpedo can mouth coating material using recycled high-alumina material, the method comprising the following steps: Step 1: Waste recycling. High-alumina waste materials are sorted and recycled, manually picked, and their composition is tested to ensure that the alumina content in the recycled materials is greater than 80%. Step 2: Raw material crushing. The waste high-alumina material selected in Step 1 is conveyed to the crusher and crushed and screened into three particle size grades: 5mm, 3mm and 1mm. Step 3: Dry mixing. By weight, take 62 parts of the recycled material obtained in Step 2, 1 part of kyanite with a particle size of 1mm, 1 part of white clay with a particle size of 200 mesh, 6 parts of grade IV fine powder with a particle size of 200 mesh, 10 parts of 625 cement with a particle size of 200 mesh, 0.1 parts of water-reducing agent, and 0.1 parts of binder. First, add the recycled material and kyanite to the mixer and mix for 3 minutes. Then add the white clay, grade IV fine powder, and 625 cement and mix for 5 minutes. Finally, add the water-reducing agent and binder and mix for 2 minutes to obtain the mixture. Step 4: Sampling and testing. Take the mixture obtained in Step 3, add water and stir, then vibrate and mold it. After demolding and drying, perform heat treatment and test the physical properties. Step 5: Packaging. Pack the mixture obtained in Step 3 and store it in a dry and cool environment.

[0021] In step one, the waste high-alumina materials include waste high-alumina bricks. During manual sorting, slag shells, metal impurities, and low-alumina impurities are removed. The alumina content is determined by X-ray fluorescence spectrometry. When the alumina content is less than 80%, it is mixed with high-alumina waste materials in a ratio of not less than 80%.

[0022] In step two, the crushers include jaw crushers, impact crushers, and double roll crushers. The crushed materials are sequentially screened through square hole screens, with 20% of the particles being 5mm, 25% being 3mm, and 55% being 1mm. The recovered materials of each particle size are stored in sealed silos after screening, with a moisture content not exceeding 0.5%.

[0023] In step three, the kyanite contains more than 50% alumina, more than 40% silica, and has a loss on ignition of no more than 1.5%. Before use, it is crushed to 1mm by a jaw crusher. After crushing, the proportion of particles larger than 1mm in the kyanite is no more than 3%. The white clay contains more than 30% alumina, more than 50% silica, and has a proportion of particles smaller than 1mm of no less than 95%. Before use, it is dried at 105℃±5℃ for 2 hours and then cooled to room temperature before use.

[0024] In step three, the alumina content of the grade IV fine powder is greater than 50%, the silica content is greater than 30%, the iron oxide content is not higher than 2.5%, and the proportion of particles with a particle size of less than 1 mm is not less than 98%. The alumina content of the 625 cement is greater than 50%, the calcium oxide content is not higher than 35%, the specific surface area is not less than 350 m² / kg, the initial setting time is not less than 45 min, the final setting time is not higher than 600 min, and it should be sealed and stored before use for no more than 30 days.

[0025] In step three, the water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of not less than 20% and an air content of not more than 3%. The binder is silica sol, in which the silica sol contains 20% silica and has a pH value of 8.

[0026] In step three, a twin-shaft paddle mixer is used for the dry mixing process. The mixing shaft speed is 300 r / min. The temperature inside the mixer is controlled at 15℃ and the relative humidity is not higher than 60% during mixing. Before adding the water-reducing agent and binder, the temperature of the mixture is adjusted to 20℃. During the mixing process, samples are taken every 2 minutes to check the mixing uniformity. Mixing is stopped when the coefficient of variation does not exceed 5%.

[0027] In step four, the water-to-material ratio is 0.14 when adding water and mixing. A planetary mixer is used for mixing at a speed of 60 r / min for 3 min. Vibration molding is performed using a vibrating table at a frequency of 50 Hz for 30 s. The size of the molded specimen is 40 mm × 40 mm × 160 mm. After demolding, it is dried at 110℃ ± 5℃ for 24 h, and then heat-treated at 1400℃ ± 10℃ for 3 h. The heating rate during heat treatment does not exceed 5℃ / min.

[0028] In step four, the physical indicators tested include bulk density, apparent porosity, compressive strength at room temperature, and flexural strength at 1400℃ for 3 hours. The passing standards are: bulk density not less than 2.2 g / cm³, apparent porosity not more than 22%, compressive strength at 110℃ for 24 hours not less than 15 MPa, and flexural strength at 1400℃ for 3 hours not less than 18 MPa.

[0029] In step five, moisture-proof composite woven bags are used for packaging, with each bag weighing 25kg ± 0.2kg net. The temperature of the mixed material should not exceed 40℃ during packaging. After packaging, the bag openings are sealed. A moisture-proof layer is laid on the floor of the storage warehouse. The stacking height should not exceed 10 layers, and the stack spacing should not be less than 0.5m. The temperature inside the warehouse is controlled at 5℃, the relative humidity should not exceed 60%, and the storage period should not exceed 90 days. A re-inspection is carried out before leaving the warehouse. The re-inspection items include moisture content and construction performance. If the moisture content is greater than 0.8%, it needs to be dried again.

[0030] Example 2: A method for preparing a torpedo can mouth coating material using recycled high-alumina material, the method comprising the following steps: Step 1: Waste recycling. High-alumina waste materials are sorted and recycled, manually picked, and their composition is tested to ensure that the alumina content in the recycled materials is greater than 80%. Step 2: Raw material crushing. The waste high-alumina material selected in Step 1 is conveyed to the crusher and crushed and screened into three particle size grades: 4mm, 2mm and 0.08mm. Step 3: Dry mixing. By weight, take 70 parts of the recycled material obtained in Step 2, 4 parts of kyanite with a particle size of 0.5mm, 7 parts of white clay with a particle size of 200 mesh, 8 parts of grade IV fine powder with a particle size of 200 mesh, 13 parts of 625 cement with a particle size of 200 mesh, 0.2 parts of water-reducing agent, and 0.3 parts of binder. First, add the recycled material and kyanite to the mixer and mix for 4 minutes. Then add the white clay, grade IV fine powder, and 625 cement and mix for 6 minutes. Finally, add the water-reducing agent and binder and mix for 3 minutes to obtain the mixture. Step 4: Sampling and testing. Take the mixture obtained in Step 3, add water and stir, then vibrate and mold it. After demolding and drying, perform heat treatment and test the physical properties. Step 5: Packaging. Pack the mixture obtained in Step 3 and store it in a dry and cool environment.

[0031] In step one, the waste high-alumina material includes waste high-alumina castable. During manual sorting, slag shells, metal impurities and low-alumina impurities are removed. The alumina content is determined by X-ray fluorescence spectrometry. When the alumina content is less than 80%, it is mixed with high-alumina waste in a ratio of not less than 80%.

[0032] In step two, the crushers include jaw crushers, impact crushers and double roll crushers. The crushed materials are screened sequentially through square hole screens, with 30% of the particles being 4mm, 20% being 2mm, and 50% being 0.08mm. The recovered materials of each particle size are stored in sealed silos after screening, with a moisture content not exceeding 0.5%.

[0033] In step three, the kyanite contains more than 50% alumina, more than 40% silica, and has a loss on ignition of no more than 1.5%. Before use, it is crushed to 0.5mm by a jaw crusher. After crushing, the proportion of particles larger than 0.5mm in the kyanite is no more than 3%. The white clay contains more than 30% alumina, more than 50% silica, and has a proportion of particles smaller than 0.08mm of no less than 95%. Before use, it is dried at 105℃±5℃ for 2 hours and then cooled to room temperature before use.

[0034] In step three, the alumina content of the grade IV fine powder is greater than 50%, the silica content is greater than 30%, the iron oxide content is not higher than 2.5%, and the proportion of particles with a particle size of less than 0.08mm is not less than 98%. The alumina content of the 625 cement is greater than 50%, the calcium oxide content is not higher than 35%, the specific surface area is not less than 350m² / kg, the initial setting time is not less than 45min, the final setting time is not higher than 600min, and it should be sealed and stored before use for no more than 30 days.

[0035] In step three, the water-reducing agent is a naphthalene-based water-reducing agent with a water reduction rate of not less than 20% and an air content of not more than 3%. The binder is aluminum dihydrogen phosphate, in which the phosphorus pentoxide content is not less than 30% and the aluminum oxide content is not less than 10%.

[0036] In step three, a twin-shaft paddle mixer is used for the dry mixing process. The mixing shaft speed is 400 r / min. The temperature inside the mixer is controlled at 25℃ and the relative humidity is not higher than 60% during mixing. Before adding the water-reducing agent and binder, the temperature of the mixture is adjusted to 23℃. During the mixing process, samples are taken every 2 minutes to check the mixing uniformity. Mixing is stopped when the coefficient of variation does not exceed 5%.

[0037] In step four, the water-to-material ratio is 0.15 when adding water and mixing. A planetary mixer is used for mixing at a speed of 80 r / min for 4 min. Vibration molding is performed using a vibrating table at a frequency of 55 Hz for 45 s. The size of the molded specimen is 40 mm × 40 mm × 160 mm. After demolding, it is dried at 110℃ ± 5℃ for 24 h and then heat-treated at 1400℃ ± 10℃ for 3 h. The heating rate during heat treatment does not exceed 5℃ / min.

[0038] In step four, the physical indicators tested include bulk density, apparent porosity, compressive strength at room temperature, and flexural strength at 1400℃ for 3 hours. The passing standards are: bulk density not less than 2.2 g / cm³, apparent porosity not more than 22%, compressive strength at 110℃ for 24 hours not less than 15 MPa, and flexural strength at 1400℃ for 3 hours not less than 18 MPa.

[0039] In step five, moisture-proof composite woven bags are used for packaging, with each bag weighing 25kg ± 0.2kg net. The temperature of the mixed material should not exceed 40℃ during packaging. After packaging, the bag openings are sealed. A moisture-proof layer is laid on the floor of the storage warehouse. The stacking height should not exceed 10 layers, and the stack spacing should not be less than 0.5m. The temperature inside the warehouse is controlled at 20℃, the relative humidity should not exceed 60%, and the storage period should not exceed 90 days. A re-inspection is carried out before leaving the warehouse. The re-inspection items include moisture content and construction performance. If the moisture content is greater than 0.8%, it needs to be dried again.

[0040] Example 3: A method for preparing a torpedo can mouth coating material using recycled high-alumina material, the method comprising the following steps: Step 1: Waste recycling. High-alumina waste materials are sorted and recycled, manually picked, and their composition is tested to ensure that the alumina content in the recycled materials is greater than 80%. Step 2: Raw material crushing. The waste high-alumina material selected in Step 1 is conveyed to the crusher and crushed and screened into three particle size grades: 3mm, 1mm and 0.074mm. Step 3: Dry mixing. By weight, take 80 parts of the recycled material obtained in Step 2, 8 parts of kyanite with a particle size of 1-0 mm, 15 parts of white clay with a particle size of 200 mesh, 11 parts of grade IV fine powder with a particle size of 200 mesh, 15 parts of 625 cement with a particle size of 200 mesh, 0.3 parts of water-reducing agent, and 0.5 parts of binder. First, add the recycled material and kyanite to the mixer and mix for 5 minutes. Then add the white clay, grade IV fine powder, and 625 cement and mix for 8 minutes. Finally, add the water-reducing agent and binder and mix for 4 minutes to obtain the mixture. Step 4: Sampling and testing. Take the mixture obtained in Step 3, add water and stir, then vibrate and mold it. After demolding and drying, perform heat treatment and test the physical properties. Step 5: Packaging. Pack the mixture obtained in Step 3 and store it in a dry and cool environment.

[0041] In step one, the waste high-alumina materials include waste high-alumina bricks. During manual sorting, slag shells, metal impurities, and low-alumina impurities are removed. The alumina content is determined by X-ray fluorescence spectrometry. When the alumina content is less than 80%, it is mixed with high-alumina waste materials in a ratio of not less than 80%.

[0042] In step two, the crushers include jaw crushers, impact crushers, and double roll crushers. The crushed materials are sequentially screened through square hole screens, with 40% of the particles being 3mm, 35% being 1mm, and 25% being 0.074mm. The recovered materials of each particle size are stored in sealed silos after screening, with a moisture content not exceeding 0.5%.

[0043] In step three, the kyanite contains more than 50% alumina, more than 40% silica, and has a loss on ignition of no more than 1.5%. Before use, it is crushed to 0.1mm by a jaw crusher. After crushing, the proportion of particles larger than 0.1mm in the kyanite is no more than 3%. The white clay contains more than 30% alumina, more than 50% silica, and has a proportion of particles smaller than 0.074mm of no less than 95%. Before use, it is dried at 105℃±5℃ for 2 hours and then cooled to room temperature before use.

[0044] In step three, the alumina content of the grade IV fine powder is greater than 50%, the silica content is greater than 30%, the iron oxide content is not higher than 2.5%, and the proportion of particles with a particle size of less than 0.074mm is not less than 98%. The alumina content of the 625 cement is greater than 50%, the calcium oxide content is not higher than 35%, the specific surface area is not less than 350m² / kg, the initial setting time is not less than 45min, the final setting time is not higher than 600min, and it should be sealed and stored before use for no more than 30 days.

[0045] In step three, the water-reducing agent is one of polycarboxylate-based high-performance water-reducing agents, naphthalene-based water-reducing agents, or lignin sulfonate water-reducing agents, with a water reduction rate of not less than 20% and an air content of not more than 3%, and the binder is modified starch ether.

[0046] In step three, a twin-shaft paddle mixer is used for the dry mixing process. The mixing shaft speed is 500 r / min. The temperature inside the mixer is controlled at 35℃ and the relative humidity is not higher than 60% during mixing. Before adding the water-reducing agent and binder, the temperature of the mixture is adjusted to 25℃. During the mixing process, samples are taken every 2 minutes to check the mixing uniformity. Mixing is stopped when the coefficient of variation does not exceed 5%.

[0047] In step four, the water-to-material ratio is 0.16 when adding water and mixing. A planetary mixer is used for mixing at a speed of 100 r / min for 5 min. Vibration molding is performed using a vibrating table at a frequency of 60 Hz for 60 s. The size of the molded specimen is 40 mm × 40 mm × 160 mm. After demolding, it is dried at 110℃ ± 5℃ for 24 h, and then heat-treated at 1400℃ ± 10℃ for 3 h. The heating rate during heat treatment does not exceed 5℃ / min.

[0048] In step four, the physical indicators tested include bulk density, apparent porosity, compressive strength at room temperature, and flexural strength at 1400℃ for 3 hours. The passing standards are: bulk density not less than 2.2 g / cm³, apparent porosity not more than 22%, compressive strength at 110℃ for 24 hours not less than 15 MPa, and flexural strength at 1400℃ for 3 hours not less than 18 MPa.

[0049] In step five, moisture-proof composite woven bags are used for packaging, with each bag weighing 25kg ± 0.2kg net. The temperature of the mixed material should not exceed 40℃ during packaging. After packaging, the bag openings are sealed. A moisture-proof layer is laid on the floor of the storage warehouse. The stacking height should not exceed 10 layers, and the stack spacing should not be less than 0.5m. The temperature inside the warehouse is controlled at 35℃, the relative humidity should not exceed 60%, and the storage period should not exceed 90 days. A re-inspection is carried out before leaving the warehouse. The re-inspection items include moisture content and construction performance. If the moisture content is greater than 0.8%, it needs to be dried again.

[0050] Comparative Example 1: The difference between this comparative example and Example 1 is that no binder was added in the dry mixing step of this comparative example.

[0051] Comparative Example 2 differs from Example 2 in that, in the raw material crushing step, the recycled material is crushed into a single particle size level without multi-stage screening.

[0052] Comparative Example 3 differs from Example 3 in that: in the waste recycling step, no manual sorting or alumina content testing was performed on the recycled materials, and unscreened high-alumina waste materials were used directly.

[0053] Comparative Example 4 differs from Example 3 in that no water-reducing agent was added in the dry mixing step, and the amount of the fourth-grade fine powder added was 15 parts.

[0054] The performance of the torpedo can mouth coating materials prepared in Examples 1-3 and Comparative Examples 1-4 was tested. The test items and test methods are as follows: For the bulk density test, the volume and mass of the sample were measured by the water displacement method under a drying environment of 110℃×24h, and the mass per unit volume was calculated. For the apparent porosity test, the sample was saturated by vacuum pumping under a drying environment of 110℃×24h, and the mass of the saturated sample and the suspended mass were measured to calculate the proportion of open pores. For the room temperature compressive strength test, under a drying environment of 110℃×24h, a universal testing machine was used to apply pressure at a loading rate of 1.0MPa / s until the sample broke, and the maximum pressure per unit area was calculated. High-temperature flexural strength test: Under the heat treatment environment of 1400℃×3h, a high-temperature flexural testing machine was used to apply a bending load at a loading rate of 0.15MPa / s, and the maximum flexural stress at the time of specimen fracture was calculated.

[0055] The test data of the torpedo canister coatings prepared in Examples 1-4 and Comparative Examples 1-4 are recorded in the table below: By comparing and analyzing the data in the table, it can be seen that the torpedo can mouth coating prepared using the process in Examples 1-4 has significantly better performance than the torpedo can mouth coating prepared using the process in Comparative Examples 1-4. This indicates that by classifying and sorting the waste high-alumina materials and conducting component testing through the waste recycling step, and adjusting the formulation according to the alumina content, the stability of the recycled materials as the core raw material is ensured. At the same time, replacing part of the virgin high-alumina raw materials with recycled high-alumina materials in the preparation of coating materials can efficiently utilize the solid waste resources of waste high-alumina bricks and waste high-alumina castables, ensuring a reduction in the production cost of torpedo can mouth coating materials, reducing the consumption of non-renewable mineral resources, and mitigating environmental pollution caused by the accumulation of technical solid waste. Through the raw material crushing step, the recycled materials are screened in multiple stages, and the proportion and moisture content of each particle size class are controlled in real time, enabling the preparation system to reduce the recycling rate. The system addresses the fluctuations in particle size distribution caused by the complex origin of the recycled materials. When abnormal deviations occur in the gradation of the mixture, the system can correct the particle size distribution in real time by adjusting crushing and screening parameters. This ensures that the particle size distribution of the recycled material accurately matches the application and density requirements of the coating, guaranteeing the uniformity of the coating's performance and the stability of its high-temperature structure. During the mixture preparation stage, by limiting the raw material indicators of kyanite, white clay, grade IV fine powder, 625 cement, water-reducing agent, and binder, and combining this with the mixing parameters and uniformity control of the dry-mixing process, the system achieves homogenization and dispersion of multiple components based on the characteristics of different raw materials. This allows the system to adapt the formula and process to different batches of recycled high-alumina material, reducing the risk of coating peeling or flaking after high-temperature use, and improving the service life of the torpedo can mouth coating and the operating efficiency of the torpedo can.

[0056] By comparing and analyzing the relevant data in the table, it can be seen that the torpedo can mouth coating material prepared by the method of the present invention has a high bulk density, a low apparent porosity, and excellent room temperature compressive strength and high temperature flexural strength. This indicates that the method of preparing torpedo can mouth coating material using recycled high-alumina material provided by the present invention has superior comprehensive performance.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a torpedo can mouth coating material using recycled high-alumina material, characterized in that, The method includes the following steps: Step 1: Waste recycling. High-alumina waste materials are sorted and recycled, manually picked, and their composition is tested to ensure that the alumina content in the recycled materials is greater than 80%. Step 2: Raw material crushing. The waste high-alumina material selected in Step 1 is conveyed to the crusher and crushed and screened into three particle size grades: 5-3mm, 3-1mm, and 1-0.074mm. Step 3: Dry mixing. By weight, take 62-80 parts of the recycled material obtained in Step 2, 0-8 parts of kyanite with a particle size of 1-0 mm, 0-15 parts of white clay with a particle size of 200 mesh, 6-11 parts of grade IV fine powder with a particle size of 200 mesh, 10-15 parts of 625 cement with a particle size of 200 mesh, 0-0.3 parts of water-reducing agent, and 0-0.5 parts of binder. First, add the recycled material and kyanite to the mixer and mix for 3-5 minutes. Then add the white clay, grade IV fine powder, and 625 cement and mix for 5-8 minutes. Finally, add the water-reducing agent and binder and mix for 2-4 minutes to obtain the mixture. Step 4: Sampling and testing. Take the mixture obtained in Step 3, add water and stir, then vibrate and mold it. After demolding and drying, perform heat treatment and test the physical properties. Step 5: Packaging. Pack the mixture obtained in Step 3 and store it in a dry and cool environment.

2. The method for preparing torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step one, the waste high-alumina material includes one of waste high-alumina bricks and waste high-alumina castables. During manual sorting, slag shells, metal impurities and low-alumina impurities are removed. The alumina content is determined by X-ray fluorescence spectrometry. When the alumina content is less than 80%, it is mixed with high-alumina waste in a ratio of not less than 80%.

3. The method for preparing torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step two, the crusher includes a jaw crusher, an impact crusher, and a double roll crusher. The crushed material is sequentially screened through a square hole screen, wherein the 5-3mm particle size accounts for 20%-40%, the 3-1mm particle size accounts for 15%-35%, and the 1-0.074mm particle size accounts for 25%-55%. The recovered material of each particle size after screening is stored in a closed silo with a moisture content of no more than 0.5%.

4. The method for preparing torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step three, the kyanite contains more than 50% alumina, more than 40% silica, and has a loss on ignition of no more than 1.5%. Before use, it is crushed to 1-0 mm by a jaw crusher. After crushing, the proportion of particles larger than 1 mm in the kyanite is no more than 3%. The white clay contains more than 30% alumina, more than 50% silica, and has a proportion of particles smaller than 0.074 mm of no less than 95%. Before use, it is dried at 105℃±5℃ for 2 hours and then cooled to room temperature before use.

5. The method for preparing torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step three, the alumina content of the fourth-grade fine powder is greater than 50%, the silica content is greater than 30%, the iron oxide content is not higher than 2.5%, and the proportion of particles with a particle size of less than 0.074 mm is not less than 98%. The alumina content of the 625 cement is greater than 50%, the calcium oxide content is not higher than 35%, the specific surface area is not less than 350 m² / kg, the initial setting time is not less than 45 min, the final setting time is not higher than 600 min, and it should be sealed and stored before use for no more than 30 days.

6. The method for preparing torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step three, the water-reducing agent is one of polycarboxylate-based high-performance water-reducing agent, naphthalene-based water-reducing agent, or lignin sulfonate water-reducing agent, with a water reduction rate of not less than 20% and an air content of not more than 3%. The binder is one of silica sol, aluminum dihydrogen phosphate, or modified starch ether, wherein the silica sol contains 20%-30% silica and has a pH value of 8-10, the aluminum dihydrogen phosphate contains not less than 30% phosphorus pentoxide and not less than 10% aluminum oxide.

7. The method for preparing torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step three, a twin-shaft paddle mixer is used for the dry mixing process. The mixing shaft speed is 300-500 r / min. The temperature inside the mixer is controlled at 15-35℃ and the relative humidity is not higher than 60%. Before adding the water-reducing agent and binder, the temperature of the mixture is adjusted to 20-25℃. During the mixing process, samples are taken every 2 minutes to check the mixing uniformity. Mixing is stopped when the coefficient of variation does not exceed 5%.

8. The method for preparing torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step four, the water-to-material ratio is 0.14-0.16 when adding water and mixing. A planetary mixer is used for mixing at a speed of 60-100 r / min for 3-5 min. Vibration molding is performed using a vibrating table at a frequency of 50-60 Hz for 30-60 s. The size of the molded specimen is 40 mm × 40 mm × 160 mm. After demolding, it is dried at 110℃ ± 5℃ for 24 h, and then heat-treated at 1400℃ ± 10℃ for 3 h. The heating rate during heat treatment should not exceed 5℃ / min.

9. A method for preparing a torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step four, the physical indicators tested include bulk density, apparent porosity, compressive strength at room temperature, and flexural strength at 1400℃ for 3 hours. The passing standards are: bulk density not less than 2.2 g / cm³, apparent porosity not more than 22%, compressive strength at 110℃ for 24 hours not less than 15 MPa, and flexural strength at 1400℃ for 3 hours not less than 18 MPa.

10. A method for preparing a torpedo can mouth coating material using recycled high-alumina material according to claim 1, characterized in that, In step five, moisture-proof composite woven bags are used for packaging, with each bag weighing 25kg ± 0.2kg net. The temperature of the mixed material should not exceed 40℃ during packaging. After packaging, the bag openings are sealed. A moisture-proof layer is laid on the floor of the storage warehouse. The stacking height should not exceed 10 layers, and the stack spacing should not be less than 0.5m. The temperature inside the warehouse is controlled between 5-35℃, the relative humidity should not exceed 60%, and the storage period should not exceed 90 days. A re-inspection is carried out before leaving the warehouse. The re-inspection items include moisture content and construction performance. If the moisture content is greater than 0.8%, it needs to be dried again.

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