High-strength steel ladle castable and its preparation method

Abstract

This invention relates to the field of ladle castable technology, specifically disclosing a high-strength ladle castable. The raw materials, by weight, include: 40-60 parts of capacitor corundum, 5-15 parts of sintered magnesium aluminum spinel, 5-10 parts of sintered magnesia, 1-5 parts of zirconium oxide powder, 1-5 parts of titanium oxide powder, 1-5 parts of magnesium oxide powder, 1-10 parts of silica powder, 1-2 parts of water-reducing agent, 1-10 parts of ceramic fiber, 1-5 parts of polyvinyl alcohol fiber, 0.1-1 parts of sodium dodecyl sulfate, 1-3 parts of calcium hydroxide, 0.1-1 parts of citric acid, 1-5 parts of nano-graphene oxide, 1-3 parts of epoxy resin, 1-2 parts of lanthanum oxide, and 0.1-1 parts of epoxy curing agent. This invention also discloses a method for preparing the above-mentioned high-strength ladle castable. Furthermore, this invention discloses the application of the above-mentioned high-strength ladle castable in steel ladles. Finally, this invention discloses a method for preparing ladle linings using the above-mentioned high-strength ladle castable.

Description

Technical Field

[0001] This invention relates to the field of ladle castable technology, and in particular to a high-strength ladle castable and its preparation method. Background Technology

[0002] The steel industry is one of the important industries in the country's industrialization development. Among them, the ironmaking system and the steelmaking system are the main processes in the steel industry production process, while the ladle is an important component for storing molten steel or iron and has a significant impact on the quality of molten iron and steel.

[0003] Steel ladle castable is a type of unshaped refractory material with advantages such as simple production process, low production cost, and excellent high-temperature performance. Currently, it is an important material for the working lining of steel ladles. Due to its advantages of fluidity, strong integrity, and high safety factor, it has great application potential in high-temperature industrial fields. In particular, its thermal conductivity, erosion resistance, and mechanical properties are very important. If not handled carefully, it can cause the steel ladle to break through, resulting in serious consequences.

[0004] Steel ladle castables are mainly composed of refractory aggregates, matrix materials, binders, and admixtures, and their performance and service life are closely related to their composition. Traditional steel ladle castables have excessively high thermal conductivity, which not only causes the molten steel to cool down too quickly, affecting the casting process, but also easily leads to overheating of the ladle itself, resulting in creep deformation or cracking. Therefore, how to provide a steel ladle castable that is both thermally insulating and has high strength is a pressing technical problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-strength steel ladle castable and its preparation method.

[0006] A high-strength steel ladle castable, the raw materials of which include, by weight: 40-60 parts of capacitor corundum, 5-15 parts of sintered magnesium aluminum spinel, 5-10 parts of sintered magnesia, 1-5 parts of zirconium oxide powder, 1-5 parts of titanium oxide powder, 1-5 parts of magnesium oxide powder, 1-10 parts of silica powder, 1-2 parts of water-reducing agent, 1-10 parts of ceramic fiber, 1-5 parts of polyvinyl alcohol fiber, 0.1-1 parts of sodium dodecyl sulfate, 1-3 parts of calcium hydroxide, 0.1-1 parts of citric acid, 1-5 parts of nano-graphene oxide, 1-3 parts of epoxy resin, 1-2 parts of lanthanum oxide, and 0.1-1 parts of epoxy curing agent.

[0007] Preferably, in the fused alumina, the mass of capacitor alumina with a particle size of 0.1-2 mm accounts for 30-60% of the total mass of capacitor alumina, the mass of capacitor alumina with a particle size of 2.5-4 mm accounts for 10-20% of the total mass of capacitor alumina, and the remainder is capacitor alumina with a particle size of 4-5 mm.

[0008] Preferably, in the sintered magnesium aluminum spinel, the mass of sintered magnesium aluminum spinel with a particle size ≤1mm accounts for 20-40% of the total mass of the sintered magnesium aluminum spinel, the mass of sintered magnesium aluminum spinel with a particle size of 1-5mm accounts for 20-40% of the total mass of the sintered magnesium aluminum spinel, and the remainder is sintered magnesium aluminum spinel with a particle size of 5-7mm.

[0009] Preferably, in sintered magnesia, the mass of sintered magnesia with a particle size ≤0.01mm accounts for 50-80% of the total mass of sintered magnesia, the mass of sintered magnesia with a particle size of 0.01-1mm accounts for 5-15% of the total mass of sintered magnesia, and the remainder is sintered magnesia with a particle size of 1-2mm.

[0010] Preferably, the particle size of zirconium oxide powder is 1-10 μm; the particle size of titanium oxide powder is 0.1-1 mm; the particle size of magnesium oxide powder is 0.1-1 mm; and the particle size of silicon micro powder is 1-2 mm.

[0011] Preferably, the water-reducing agent is a polycarboxylate water-reducing agent.

[0012] The preparation method of the above-mentioned high-strength steel ladle castable includes the following steps:

[0013] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix water-reducing agent, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0014] S2. Add calcium hydroxide and citric acid to water and stir for 10-30 minutes. Adjust the pH of the system to 7.1-7.6 using phosphoric acid. Add nano-graphene oxide and stir at 90-100℃ for 1-2 hours. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide and water and mix and grind evenly. Add aggregate, base material and additives and stir for 5-15 minutes. Add epoxy curing agent and continue stirring for 1-5 minutes to obtain premix.

[0015] S3. Add water to the premixed material, pour it into the mold to form, and refrigerate it from the bottom of the mold to -10 to -20℃. Keep it warm for 10-30 minutes, then raise it to room temperature and let it cure naturally for 3-7 days. Demold it and bake it at 200-240℃ for 30-35 hours, then raise the temperature to 750-820℃ for 10-20 hours, and then raise the temperature to 1000-1080℃ for 5-12 hours.

[0016] Preferably, in S2, the concentration of phosphoric acid is 0.1-1 mol / L.

[0017] The application of the above-mentioned high-strength steel ladle castable in steel ladles.

[0018] The method for preparing a ladle liner using the above-mentioned high-strength steel ladle castable includes the following steps: adding water to the above-mentioned high-strength steel ladle castable, pouring it into a mold for molding, cooling it from the bottom of the mold to -10 to -20℃, holding it at that temperature for 10-30 minutes, raising it to room temperature, naturally curing it for 3-7 days, demolding it, baking it at 200-240℃ for 30-35 hours, raising the temperature to 750-820℃ for 10-20 hours, and raising the temperature to 1000-1080℃ for 5-12 hours.

[0019] Preferably, the mass ratio of water to the above-mentioned high-strength steel ladle castable is 2-6:100.

[0020] Preferably, during the cooling process to -10 to -20°C, the cooling rate is 1-2°C / min.

[0021] Beneficial effects:

[0022] 1. Nano-graphene oxide has a layered structure at the microscopic level. In this invention, hydroxyapatite is deposited on the surface of its layered structure, and then compounded and ground with epoxy resin. The two materials not only have good affinity but also extremely high dispersion uniformity. The product has excellent compatibility with aggregates and matrix materials. During the molding process, the temperature is lowered by directional freezing treatment. As ice crystals grow, a regular directional porous morphology is formed in the system at the bottom of the mold. After the ice peak reaches the top of the mold, the ice crystals transform into a layered structure, causing the particle morphology at the top of the mold to rearrange and form a layered structure. After natural curing, baking is carried out, which not only forms a regular microporous structure, reducing the weight of the ladle, but also greatly enhances the thermal insulation performance of the ladle by creating a regular microporous structure without obvious horizontal and vertical interfaces.

[0023] 2. This invention uses epoxy resin and lanthanum oxide compound, which can not only effectively adjust the adhesiveness of the castable, but also effectively ensure the good formability of the castable during baking, and make up for the negative impact of the regular porous structure on the strength of the ladle, ensuring the compressive strength of the product. At the same time, the product after high-temperature carbonization and the porous structure formed by shaping and freezing are combined to significantly improve the uniformity of micropores after the ladle is formed, and further enhance the thermal insulation performance.

[0024] Through experiments, the applicant discovered that using lanthanum oxide not only promotes more uniform fusion between components, but also provides secondary reinforcement after baking, further reducing creep deformation or cracking. Specifically, by controlling the ratio of lanthanum oxide, nano-graphene oxide, and epoxy resin, if the epoxy resin content is too low, the product stability will be poor during molding, making the product prone to cracking and deformation. Conversely, if the epoxy resin content is too high, the resistance of ice crystal repulsion particles will increase, resulting in an incomplete porous structure and poor thermal insulation performance.

[0025] 3. While ensuring the strength of the steel ladle, this invention overcomes the shortcomings of traditional carbon steel ladle casting materials. It not only has good formability during molding and sintering, but also improves the refractoriness and compressive strength of the steel ladle. At the same time, the casting material is lightweight and has excellent thermal insulation properties, making it suitable for large-scale application. Attached Figure Description

[0026] Figure 1 This is a comparison chart of the porosity and bulk density of the ladle linings obtained in Example 5 and Comparative Examples 1-3.

[0027] Figure 2 This is a comparison chart of the room temperature flexural strength and room temperature compressive strength of the steel ladle linings obtained in Example 5 and Comparative Examples 1-3.

[0028] Figure 3 This is a comparison chart of the refractoriness and thermal conductivity of the ladle linings obtained in Example 5 and Comparative Examples 1-3. Detailed Implementation

[0029] The present invention will be further explained below with reference to specific embodiments.

[0030] The fused alumina used below was purchased from Zhengzhou Yifan Refractory Materials Co., Ltd. The mass of capacitor alumina with a particle size of 0.1-2mm accounts for 45% of the total mass of capacitor alumina, the mass of capacitor alumina with a particle size of 2.5-4mm accounts for 15% of the total mass of capacitor alumina, and the remainder is capacitor alumina with a particle size of 4-5mm.

[0031] The sintered magnesia-alumina spinel used below was purchased from Dashiqiao Guohong Refractory Materials Co., Ltd. The mass of sintered magnesia-alumina spinel with a particle size ≤1mm accounts for 30% of the total mass of sintered magnesia-alumina spinel, the mass of sintered magnesia-alumina spinel with a particle size of 1-5mm accounts for 30% of the total mass of sintered magnesia-alumina spinel, and the balance is sintered magnesia-alumina spinel with a particle size of 5-7mm.

[0032] The sintered magnesia used below was purchased from Gejiatun Magnesia Plant in Fengrun District, Tangshan City. The mass of sintered magnesia with a particle size ≤0.01mm accounted for 65% of the total mass of sintered magnesia, the mass of sintered magnesia with a particle size of 0.01-1mm accounted for 10% of the total mass of sintered magnesia, and the remainder was sintered magnesia with a particle size of 1-2mm.

[0033] Example 1

[0034] The high-strength steel ladle castable contains the following raw materials: 40 kg of capacitor corundum, 5 kg of sintered magnesium aluminum spinel, 5 kg of sintered magnesia, 1 kg of zirconium oxide powder with a particle size of 1-10 μm, 1 kg of titanium oxide powder with a particle size of 0.1-1 mm, 1 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 1 kg of silica powder with a particle size of 1-2 mm, 1 kg of polycarboxylate superplasticizer, 1 kg of ceramic fiber, 1 kg of polyvinyl alcohol fiber, 0.1 kg of sodium dodecyl sulfate, 1 kg of calcium hydroxide, 0.1 kg of citric acid, 1 kg of nano-graphene oxide, 1 kg of epoxy resin, 1 kg of lanthanum oxide, and 0.1 kg of triethylenetetramine.

[0035] The preparation method of the above-mentioned high-strength steel ladle castable includes the following steps:

[0036] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0037] S2. Add calcium hydroxide and citric acid to 10 kg of water and stir at 100 r / min for 10 min. Adjust the pH of the system to 7.1-7.6 using 0.1 mol / L phosphoric acid. Add nano-graphene oxide and stir at 90℃ for 1 h. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide and 1 kg of water and mix and grind evenly. Add aggregate, base material and additives and stir at 100 r / min for 5 min. Add triethylenetetramine and continue stirring for 1 min.

[0038] The method for preparing a ladle liner using the above-mentioned high-strength steel ladle castable includes the following steps: adding water to the above-mentioned high-strength steel ladle castable, wherein the mass ratio of water to the above-mentioned high-strength steel ladle castable is 2:100, pouring it into a mold for molding, subjecting it to cooling treatment from the bottom of the mold, cooling it to -10°C at a rate of 1°C / min, holding it at that temperature for 10 min, raising it to room temperature, naturally curing it for 3 days, demolding it, sending it into an oven, baking it at 200°C for 30 h, raising the temperature to 750°C for 10 h, and raising the temperature to 1000°C for 5 h.

[0039] Example 2

[0040] The high-strength steel ladle castable contains the following raw materials: 60 kg of capacitor corundum, 15 kg of sintered magnesium aluminum spinel, 10 kg of sintered magnesia, 5 kg of zirconium oxide powder with a particle size of 1-10 μm, 5 kg of titanium oxide powder with a particle size of 0.1-1 mm, 5 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 10 kg of silica powder with a particle size of 1-2 mm, 2 kg of polycarboxylate superplasticizer, 10 kg of ceramic fiber, 5 kg of polyvinyl alcohol fiber, 1 kg of sodium dodecyl sulfate, 3 kg of calcium hydroxide, 1 kg of citric acid, 5 kg of nano-graphene oxide, 3 kg of epoxy resin, 2 kg of lanthanum oxide, and 1 kg of triethylenetetramine.

[0041] The preparation method of the above-mentioned high-strength steel ladle castable includes the following steps:

[0042] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0043] S2. Add calcium hydroxide and citric acid to 20 kg of water and stir at 200 r / min for 30 min. Adjust the pH of the system to 7.1-7.6 with 1 mol / L phosphoric acid. Add nano-graphene oxide and stir at 100℃ for 2 h. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide and 3 kg of water and mix and grind evenly. Add aggregate, base material and additives and stir at 1000 r / min for 15 min. Add triethylenetetramine and continue stirring for 5 min.

[0044] The method for preparing a ladle liner using the above-mentioned high-strength steel ladle castable includes the following steps: adding water to the above-mentioned high-strength steel ladle castable, wherein the mass ratio of water to the above-mentioned high-strength steel ladle castable is 6:100, pouring it into a mold for molding, subjecting it to cooling treatment from the bottom of the mold, cooling it to -20°C at a rate of 2°C / min, holding it at that temperature for 30 minutes, raising it to room temperature, naturally curing it for 7 days, demolding it, sending it into an oven, baking it at 240°C for 35 hours, raising the temperature to 820°C for 20 hours, and raising the temperature to 1080°C for 12 hours.

[0045] Example 3

[0046] The high-strength steel ladle castable contains the following raw materials: 45 kg of capacitor corundum, 12 kg of sintered magnesium aluminum spinel, 7 kg of sintered magnesia, 4 kg of zirconium oxide powder with a particle size of 1-10 μm, 2 kg of titanium oxide powder with a particle size of 0.1-1 mm, 4 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 3 kg of silica powder with a particle size of 1-2 mm, 1.7 kg of polycarboxylate superplasticizer, 4 kg of ceramic fiber, 4 kg of polyvinyl alcohol fiber, 0.3 kg of sodium dodecyl sulfate, 2.5 kg of calcium hydroxide, 0.3 kg of citric acid, 4 kg of nano-graphene oxide, 1.5 kg of epoxy resin, 1.7 kg of lanthanum oxide, and 0.2 kg of triethylenetetramine.

[0047] The preparation method of the above-mentioned high-strength steel ladle castable includes the following steps:

[0048] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0049] S2. Add calcium hydroxide and citric acid to 18 kg of water and stir at 130 r / min for 25 min. Adjust the pH of the system to 7.1-7.6 using 0.3 mol / L phosphoric acid. Add nano-graphene oxide and stir at 98℃ for 80 min. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide, and 2.5 kg of water, mix and grind evenly. Add aggregate, base material, and additives, and stir at 300 r / min for 12 min. Add triethylenetetramine and continue stirring for 2 min.

[0050] The method for preparing a ladle liner using the above-mentioned high-strength steel ladle castable includes the following steps: adding water to the above-mentioned high-strength steel ladle castable, wherein the mass ratio of water to the above-mentioned high-strength steel ladle castable is 5:100, pouring it into a mold for molding, subjecting it to cooling treatment from the bottom of the mold, cooling it to -18°C at a rate of 1.3°C / min, holding it at that temperature for 15 minutes, raising it to room temperature, naturally curing it for 6 days, demolding it, and sending it into an oven for baking at 210°C for 33 hours, raising the temperature to 770°C for 18 hours, and raising the temperature to 1020°C for 10 hours.

[0051] Example 4

[0052] The high-strength steel ladle castable contains the following raw materials: 55 kg of capacitor corundum, 8 kg of sintered magnesium aluminum spinel, 9 kg of sintered magnesia, 2 kg of zirconium oxide powder with a particle size of 1-10 μm, 4 kg of titanium oxide powder with a particle size of 0.1-1 mm, 2 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 7 kg of silica powder with a particle size of 1-2 mm, 1.3 kg of polycarboxylate superplasticizer, 8 kg of ceramic fiber, 2 kg of polyvinyl alcohol fiber, 0.7 kg of sodium dodecyl sulfate, 1.5 kg of calcium hydroxide, 0.7 kg of citric acid, 2 kg of nano-graphene oxide, 2.5 kg of epoxy resin, 1.3 kg of lanthanum oxide, and 0.8 kg of triethylenetetramine.

[0053] The preparation method of the above-mentioned high-strength steel ladle castable includes the following steps:

[0054] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0055] S2. Add calcium hydroxide and citric acid to 12 kg of water and stir at 170 r / min for 15 min. Adjust the pH of the system to 7.1-7.6 using 0.7 mol / L phosphoric acid. Add nano-graphene oxide and stir at 92℃ for 100 min. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide, and 1.5 kg of water, mix and grind evenly. Add aggregate, base material, and additives, and stir at 700 r / min for 8 min. Add triethylenetetramine and continue stirring for 4 min.

[0056] The method for preparing a ladle liner using the above-mentioned high-strength steel ladle castable includes the following steps: adding water to the above-mentioned high-strength steel ladle castable, wherein the mass ratio of water to the above-mentioned high-strength steel ladle castable is 3:100, pouring it into a mold for molding, subjecting it to cooling treatment from the bottom of the mold, cooling it to -12°C at a rate of 1.7°C / min, holding it at that temperature for 25 minutes, raising it to room temperature, naturally curing it for 4 days, demolding it, and sending it into an oven for baking at 230°C for 31 hours, raising the temperature to 800°C for 12 hours, and raising the temperature to 1060°C for 6 hours.

[0057] Example 5

[0058] The high-strength steel ladle castable contains the following raw materials: 50 kg of capacitor corundum, 10 kg of sintered magnesium aluminum spinel, 8 kg of sintered magnesia, 3 kg of zirconium oxide powder with a particle size of 1-10 μm, 3 kg of titanium oxide powder with a particle size of 0.1-1 mm, 3 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 5 kg of silica powder with a particle size of 1-2 mm, 1.5 kg of polycarboxylate superplasticizer, 6 kg of ceramic fiber, 3 kg of polyvinyl alcohol fiber, 0.5 kg of sodium dodecyl sulfate, 2 kg of calcium hydroxide, 0.5 kg of citric acid, 3 kg of nano-graphene oxide, 2 kg of epoxy resin, 1.5 kg of lanthanum oxide, and 0.5 kg of triethylenetetramine.

[0059] The preparation method of the above-mentioned high-strength steel ladle castable includes the following steps:

[0060] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0061] S2. Add calcium hydroxide and citric acid to 15 kg of water and stir at 150 r / min for 20 min. Adjust the pH of the system to 7.1-7.6 using 0.5 mol / L phosphoric acid. Add nano-graphene oxide and stir at 95℃ for 90 min. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide, and 2 kg of water, mix and grind evenly. Add aggregate, base material, and additives, and stir at 500 r / min for 10 min. Add triethylenetetramine and continue stirring for 3 min.

[0062] The method for preparing a ladle liner using the above-mentioned high-strength steel ladle castable includes the following steps: adding water to the above-mentioned high-strength steel ladle castable, wherein the mass ratio of water to the above-mentioned high-strength steel ladle castable is 4:100, pouring it into a mold for molding, subjecting it to cooling treatment from the bottom of the mold, cooling it to -15°C at a rate of 1.5°C / min, holding it at that temperature for 20 minutes, raising it to room temperature, naturally curing it for 5 days, demolding it, sending it into an oven, baking it at 220°C for 32 hours, raising the temperature to 780°C for 15 hours, and raising the temperature to 1040°C for 8 hours.

[0063] Comparative Example 1

[0064] The steel ladle castable contains the following raw materials: 50 kg of capacitor corundum, 10 kg of sintered magnesium aluminum spinel, 8 kg of sintered magnesia, 3 kg of zirconium oxide powder with a particle size of 1-10 μm, 3 kg of titanium oxide powder with a particle size of 0.1-1 mm, 3 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 5 kg of silica powder with a particle size of 1-2 mm, 1.5 kg of polycarboxylate superplasticizer, 6 kg of ceramic fiber, 3 kg of polyvinyl alcohol fiber, 0.5 kg of sodium dodecyl sulfate, 3 kg of nano-graphene oxide, 2 kg of epoxy resin, 1.5 kg of lanthanum oxide, and 0.5 kg of triethylenetetramine.

[0065] The preparation method of the above-mentioned ladle castable includes the following steps:

[0066] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0067] S2. Add nano-graphene oxide to epoxy resin, lanthanum oxide, and 2 kg of water, mix and grind evenly, add aggregate, base material, and additives, stir at 500 r / min for 10 min, add triethylenetetramine and continue stirring for 3 min.

[0068] The method for preparing a ladle liner using the above-mentioned ladle castable includes the following steps: adding water to the above-mentioned ladle castable, wherein the mass ratio of water to the above-mentioned ladle castable is 4:100, pouring it into a mold for molding, subjecting it to cooling treatment from the bottom of the mold, cooling it to -15°C at a rate of 1.5°C / min, holding it at that temperature for 20 minutes, raising it to room temperature, naturally curing it for 5 days, demolding it, and sending it into an oven for baking at 220°C for 32 hours, raising the temperature to 780°C for 15 hours, and raising the temperature to 1040°C for 8 hours.

[0069] Comparative Example 2

[0070] The steel ladle castable contains the following raw materials: 50 kg of capacitor corundum, 10 kg of sintered magnesium aluminum spinel, 8 kg of sintered magnesia, 3 kg of zirconium oxide powder with a particle size of 1-10 μm, 3 kg of titanium oxide powder with a particle size of 0.1-1 mm, 3 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 5 kg of silica powder with a particle size of 1-2 mm, 1.5 kg of polycarboxylate superplasticizer, 6 kg of ceramic fiber, 3 kg of polyvinyl alcohol fiber, 0.5 kg of sodium dodecyl sulfate, 2 kg of calcium hydroxide, 0.5 kg of citric acid, 3 kg of nano-graphene oxide, 2 kg of epoxy resin, and 0.5 kg of triethylenetetramine.

[0071] The preparation method of the above-mentioned ladle castable includes the following steps:

[0072] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0073] S2. Add calcium hydroxide and citric acid to 15 kg of water and stir at 150 r / min for 20 min. Adjust the pH of the system to 7.1-7.6 using 0.5 mol / L phosphoric acid. Add nano-graphene oxide and stir at 95℃ for 90 min. Filter, wash, freeze dry, add epoxy resin and 2 kg of water, mix and grind evenly. Add aggregate, base material and additives, stir at 500 r / min for 10 min, add triethylenetetramine and continue stirring for 3 min.

[0074] The method for preparing a ladle liner using the above-mentioned ladle castable includes the following steps: adding water to the above-mentioned ladle castable, wherein the mass ratio of water to the above-mentioned ladle castable is 4:100, pouring it into a mold for molding, subjecting it to cooling treatment from the bottom of the mold, cooling it to -15°C at a rate of 1.5°C / min, holding it at that temperature for 20 minutes, raising it to room temperature, naturally curing it for 5 days, demolding it, and sending it into an oven for baking at 220°C for 32 hours, raising the temperature to 780°C for 15 hours, and raising the temperature to 1040°C for 8 hours.

[0075] Comparative Example 3

[0076] The steel ladle castable contains the following raw materials: 50 kg of capacitor corundum, 10 kg of sintered magnesium aluminum spinel, 8 kg of sintered magnesia, 3 kg of zirconium oxide powder with a particle size of 1-10 μm, 3 kg of titanium oxide powder with a particle size of 0.1-1 mm, 3 kg of magnesium oxide powder with a particle size of 0.1-1 mm, 5 kg of silica powder with a particle size of 1-2 mm, 1.5 kg of polycarboxylate superplasticizer, 6 kg of ceramic fiber, 3 kg of polyvinyl alcohol fiber, 0.5 kg of sodium dodecyl sulfate, 2 kg of calcium hydroxide, 0.5 kg of citric acid, 3 kg of nano-graphene oxide, 2 kg of epoxy resin, 1.5 kg of lanthanum oxide, and 0.5 kg of triethylenetetramine.

[0077] The preparation method of the above-mentioned ladle castable includes the following steps:

[0078] S1. Mix capacitor corundum, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silicon micro powder evenly to obtain base material; mix polycarboxylate superplasticizer, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives.

[0079] S2. Add calcium hydroxide and citric acid to 15 kg of water and stir at 150 r / min for 20 min. Adjust the pH of the system to 7.1-7.6 using 0.5 mol / L phosphoric acid. Add nano-graphene oxide and stir at 95℃ for 90 min. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide, and 2 kg of water, mix and grind evenly. Add aggregate, base material, and additives, and stir at 500 r / min for 10 min. Add triethylenetetramine and continue stirring for 3 min.

[0080] The method for preparing a ladle liner using the above-mentioned ladle castable includes the following steps: adding water to the above-mentioned ladle castable, wherein the mass ratio of water to the above-mentioned ladle castable is 4:100, pouring it into a mold for molding, curing it naturally at room temperature for 5 days, demolding it, sending it into a baking oven, baking it at 220℃ for 32 hours, raising the temperature to 780℃ for 15 hours, and raising the temperature to 1040℃ for 8 hours.

[0081] The porosity of the ladle linings obtained in Example 5 and Comparative Examples 1-3 was determined, and the bulk density, room temperature flexural strength, room temperature compressive strength, and refractoriness of the ladle linings obtained in Example 5 and Comparative Examples 1-3 were tested with reference to YB / T 5083-2014 "Clay and High-Alumina Dense Refractory Castables". The thermal conductivity of the ladle linings obtained in Example 5 and Comparative Examples 1-3 was tested with reference to GB / T 5990-2021 "Test Methods for Thermal Conductivity, Specific Heat Capacity and Thermal Diffusivity of Refractory Materials (Hot Wire Method)".

[0082] like Figure 1 As shown, the steel ladle lining obtained in Example 5 had the highest porosity and the lowest bulk density, which was better than Comparative Examples 2-3 (P < 0.05), but there was no significant difference compared with Comparative Example 1 (P > 0.05).

[0083] like Figure 2 As shown, the room temperature flexural strength and room temperature compressive strength of the steel ladle lining obtained in Example 5 are similar to those of Comparative Example 3 (P > 0.05), and superior to those of Comparative Examples 1-2 (P < 0.05), confirming that the steel ladle lining obtained in this invention contains a regular porous structure, but can still achieve high strength.

[0084] like Figure 3 As shown, the refractory resistance and thermal conductivity of the ladle lining obtained in Example 5 are significantly better than those of Comparative Examples 1-3 (P<0.05).

[0085] The permanent linear changes (1550℃×3h) of the ladle linings obtained in Example 5 and Comparative Examples 1-3 were tested according to YB / T 5083-2014 "Clay and High-Alumina Dense Refractory Castables", as shown in the table below:

[0086]

[0087] The applicant believes that the above-mentioned results are due to the following: Firstly, the present invention deposits hydroxyapatite on the surface of nano-graphene oxide sheet structure, and then combines it with epoxy resin through grinding. The two materials not only have good affinity but also extremely high dispersion uniformity. Secondly, the product has excellent compatibility with aggregates and matrix materials. During the molding process, directional freezing is used for cooling. As ice crystals grow, a regular, directional porous morphology is formed in the system at the bottom of the mold. After the ice peak reaches the top of the mold, the ice crystals transform into a sheet structure, causing the particle morphology at the top of the mold to rearrange and form a sheet structure. After natural curing and baking, not only does it form… The regular microporous structure reduces the weight of the ladle, and the horizontal and vertical regular microporous structure without obvious interfaces greatly enhances the thermal insulation performance of the ladle. On the other hand, the present invention uses epoxy resin and lanthanum oxide compound, which can not only effectively adjust the adhesiveness of the castable, but also effectively ensure the good formability of the castable during baking, and make up for the negative impact of the regular porous structure on the strength of the ladle, ensuring the compressive strength of the product. At the same time, the product after high-temperature carbonization and the porous structure formed by shaping and freezing are combined to significantly improve the uniformity of micropores after the ladle is formed, and further enhance the thermal insulation performance.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a ladle lining using a high-strength steel ladle castable, characterized in that, The process includes the following steps: adding water to the high-strength steel ladle castable, pouring it into the mold to form the shape, cooling it from the bottom of the mold to -10 to -20℃, holding it at that temperature for 10-30 minutes, raising it to room temperature, curing it naturally for 3-7 days, demolding it, baking it at 200-240℃ for 30-35 hours, raising the temperature to 750-820℃ for 10-20 hours, and raising the temperature to 1000-1080℃ for 5-12 hours. The high-strength steel ladle castable comprises the following raw materials by weight: 40-60 parts fused alumina, 5-15 parts sintered magnesium aluminum spinel, 5-10 parts sintered magnesia, 1-5 parts zirconium oxide powder, 1-5 parts titanium oxide powder, 1-5 parts magnesium oxide powder, 1-10 parts silica powder, 1-2 parts water-reducing agent, 1-10 parts ceramic fiber, 1-5 parts polyvinyl alcohol fiber, 0.1-1 parts sodium dodecyl sulfate, 1-3 parts calcium hydroxide, 0.1-1 parts citric acid, 1-5 parts nano-graphene oxide, 1-3 parts epoxy resin, 1-2 parts lanthanum oxide, and 0.1-1 parts epoxy curing agent.

2. The method for preparing ladle linings using high-strength steel ladle castable according to claim 1, characterized in that, In fused alumina, fused alumina with a particle size of 0.1-2 mm accounts for 30-60% of the total mass of fused alumina, fused alumina with a particle size of 2.5-4 mm accounts for 10-20% of the total mass of fused alumina, and the remainder is fused alumina with a particle size of 4-5 mm.

3. The method for preparing a ladle lining using high-strength steel ladle castable according to claim 1, characterized in that, In sintered magnesium aluminum spinel, sintered magnesium aluminum spinel with a particle size ≤1mm accounts for 20-40% of the total mass of sintered magnesium aluminum spinel, sintered magnesium aluminum spinel with a particle size of 1-5mm accounts for 20-40% of the total mass of sintered magnesium aluminum spinel, and the remainder is sintered magnesium aluminum spinel with a particle size of 5-7mm.

4. The method for preparing a ladle lining using high-strength steel ladle castable according to claim 1, characterized in that, In sintered magnesia, sintered magnesia with a particle size ≤0.01mm accounts for 50-80% of the total mass of sintered magnesia, sintered magnesia with a particle size of 0.01-1mm accounts for 5-15% of the total mass of sintered magnesia, and the remainder is sintered magnesia with a particle size of 1-2mm.

5. The method for preparing a ladle lining using the high-strength steel ladle castable according to claim 1, characterized in that, The particle size of zirconium oxide powder is 1-10 μm; the particle size of titanium oxide powder is 0.1-1 mm; and the particle size of magnesium oxide powder is 0.1-1 mm.

6. The method for preparing a ladle lining using the high-strength steel ladle castable according to claim 1, characterized in that, The water-reducing agent is a polycarboxylate water-reducing agent.

7. The method for preparing a ladle lining using the high-strength steel ladle castable according to claim 1, characterized in that, The high-strength steel ladle castable is prepared using the following steps: S1. Mix fused alumina, sintered magnesium aluminum spinel, and sintered magnesia evenly to obtain aggregate; mix zirconium oxide powder, titanium oxide powder, magnesium oxide powder, and silica powder evenly to obtain base material; mix water-reducing agent, ceramic fiber, polyvinyl alcohol fiber, and sodium dodecyl sulfate evenly to obtain additives. S2. Add calcium hydroxide and citric acid to water and stir for 10-30 minutes. Adjust the pH of the system to 7.1-7.6 with phosphoric acid. Add nano-graphene oxide and stir at 90-100℃ for 1-2 hours. Filter, wash, freeze dry, add epoxy resin, lanthanum oxide and water and mix and grind evenly. Add aggregate, base material and additives and stir for 5-15 minutes. Add epoxy curing agent and continue stirring for 1-5 minutes.

8. The method for preparing a ladle lining using the high-strength steel ladle castable according to claim 7, characterized in that, In S2, the concentration of phosphoric acid is 0.1-1 mol / L.

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