Erosion resistant refractory for taphole preforms and method of making same

Abstract

This invention discloses an anti-erosion refractory material for steel tapping preforms and its preparation method, belonging to the field of refractory material preparation. It primarily addresses the technical problem that the thermal shock resistance and slag erosion resistance of refractory materials used for steel tapping preforms need further improvement. Specifically, it comprises the following components by weight: 4-6 parts borosilicate-modified phenolic resin, 1-3 parts coated modified short fibers, 50-60 parts fused white corundum, 15-20 parts sintered corundum, 5-10 parts fused aluminum-magnesium spinel powder, and 1-3 parts metallic silicon powder. This invention improves the preparation of modified carbon fibers and borosilicate-hybridized phenolic resin for zirconium-aluminum ceramic encapsulation. These are blended with multi-stage inorganic aggregates, and then subjected to hot-press molding and gradient temperature curing to crosslink and construct a three-dimensional dense multiphase refractory system, resulting in an anti-erosion refractory material that significantly improves the thermal shock resistance and slag erosion resistance of the anti-erosion refractory material.

Description

Technical Field

[0001] This invention relates to the field of refractory material preparation, specifically to an anti-corrosion refractory material for steel tapping precast parts and its preparation method. Background Technology

[0002] The precast components at the tapping spout are subjected to a complex service environment involving molten steel erosion, slag corrosion, rapid temperature fluctuations, and oxidizing atmospheres. Their corrosion resistance and thermal shock resistance directly affect the service life and stability of the continuous casting process. In recent years, the development trend of refractory materials has gradually shifted from simply improving room temperature and high temperature strength to comprehensively controlling performance in terms of density, impermeability, erosion resistance, oxidation resistance, and thermal stress mitigation. Especially for carbonaceous refractory systems, how to maintain structural integrity while inhibiting slag penetration, reducing thermal shock cracking, and delaying spalling failure during service life has become a key technical issue of continuous concern in the field of precast components at the tapping spout.

[0003] Corrosion-resistant refractory materials used for steel tapping precast components often employ corundum, spinel, and other materials to construct the main system. They are frequently modified by introducing carbide or nitride micro powders, adding whiskers, or using surface coatings. Although these modifications can improve local performance to some extent, they still generally suffer from problems such as insufficient high-temperature stability of the bonding phase, easy oxidation and burn-off of the carbonaceous reinforcing phase, weak interface matching between different phases, and easy penetration of corrosive media along pores or interface channels. As a result, the materials are still prone to crack propagation, loose structure, and reduced corrosion resistance under thermal shock cycles and the coupling effect of steel and slag.

[0004] Currently, in the preparation of corrosion-resistant refractory materials for steel tapping precast components, the organic bonding phase is prone to shrinkage, cracking or oxidation during heat treatment and service, making it difficult to maintain the interfacial bonding strength and pore structure stability of the matrix. Furthermore, the wettability and anchoring between the fiber and the inorganic matrix are limited, which can easily form weak interfacial zones at high temperatures and further evolve into crack initiation and penetration propagation channels. In addition, some reinforcing or protective components lack the ability to densify in situ at high temperatures, making it difficult to simultaneously achieve thermal shock resistance and corrosion resistance.

[0005] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-corrosion refractory material for steel tapping preforms and its preparation method, mainly addressing the technical problem that the thermal shock resistance and slag erosion resistance of refractory materials for steel tapping preforms need to be further improved.

[0007] The objective of this invention can be achieved through the following technical solution: an anti-corrosion refractory material for steel tapping precast parts, comprising the following components by weight: 4-6 parts borosilicate synergistic modified phenolic resin, 1-3 parts coated modified short fibers, 50-60 parts fused white corundum, 15-20 parts sintered corundum, 5-10 parts fused aluminum-magnesium spinel powder and 1-3 parts metallic silicon powder;

[0008] The borosilicate-modified phenolic resin is prepared by the following steps:

[0009] A1. Place phenol in a reaction vessel and stir. Add paraformaldehyde and barium hydroxide. Heat the reaction vessel to 75-85℃ and keep it at that temperature for 1-2 hours. Add oxalic acid solution to adjust the pH to 3.5-4.5. Add boric acid. Heat the reaction vessel to 90-95℃ and dehydrate under reduced pressure until the free phenol content is ≤5%. Post-process to obtain boron-containing phenolic prepolymer.

[0010] A2. Place boron-containing phenolic prepolymer, ethanol, deionized water and 3-(2,3-epoxypropoxy)propyltrimethoxysilane in a reaction vessel under nitrogen atmosphere and stir. Add triethylamine to adjust the pH to 8-8.5. Heat the reaction vessel to 50-60℃ and keep it at that temperature for 2-4 hours. Post-treatment yields boron-silicon synergistic modified phenolic resin.

[0011] Further, in step A1, the weight ratio of phenol, paraformaldehyde, barium hydroxide, and boric acid is 8-10:3-5:0.2-0.4:1-2, and the concentration of oxalic acid solution is 14-16 wt%. The post-processing steps include: after the reaction is completed, the reaction system is cooled to 40-50℃, allowed to stand and cool to crystallize, filtered, and the filtrate is transferred to a rotary evaporator at a temperature of 70-80℃, evaporated under reduced pressure for 30-60 minutes, sealed and stored to obtain boron-containing phenolic prepolymer.

[0012] Further, in step A2, the ratio of the boron-containing phenolic prepolymer, ethanol, deionized water, and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 16-18g:18-20mL:0.1-0.15mL:0.3-0.5g. The subsequent steps include: after the reaction is completed, the reaction system is cooled to room temperature, the reaction solution is transferred to a rotary evaporator at a temperature of 55-65℃, and the evaporation is carried out under reduced pressure until no solvent is distilled off. The remaining material is allowed to stand and age for 1-2 hours, filtered to remove trace amounts of flocculent impurities, and dried under vacuum at 60-80℃ to constant weight. After cooling, it is sealed and stored to obtain boron-silicon synergistic modified phenolic resin.

[0013] Furthermore, the coated modified short fibers are prepared by the following steps:

[0014] B1. Place concentrated nitric acid in a reaction vessel and stir. Add short-cut carbon fibers. Heat the reaction vessel to 60-80℃ and keep it at that temperature for 0.5-1h. Then, perform post-treatment to obtain pretreated short fibers.

[0015] B2. The pretreated short fibers are impregnated in modified zirconia sol and stirred at room temperature for 1-2 hours. The post-treatment yields the coated modified short fiber crude product.

[0016] B3. Add the coated modified short fiber crude product into a tube furnace under nitrogen atmosphere protection, heat it to 600-800℃ at a heating rate of 2-5℃, hold it at that temperature for 2-3 hours, and then cool it with the furnace to obtain the coated modified short fiber.

[0017] Furthermore, in step B1, the ratio of concentrated nitric acid to chopped carbon fibers is 40 mL: 1 g. The post-treatment steps include: after the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with deionized water and ethanol until neutral, transferred to an oven at 50-60°C, and dried to constant weight to obtain pretreated short fibers.

[0018] Furthermore, in step B2, the solid-liquid ratio of the pretreated short fibers and the modified zirconia sol is 1:30-32. The post-treatment steps include: after the reaction is completed, the fibers are filtered, transferred to an oven at 60-70℃ for pre-drying for 1-2 hours, and then transferred to an oven at 60-80℃ for drying for 1-2 hours to obtain the coated modified short fiber crude product.

[0019] Furthermore, the modified zirconia sol is prepared by the following steps:

[0020] C1. Place deionized water and ethanol in a reaction vessel and stir. Add nitric acid solution to adjust the pH of the system to 2-3 to obtain the hydrolysis precursor solution.

[0021] C2. Place zirconium propoxide, aluminum isopropoxide and ethanol in a reaction vessel and stir. Add glacial acetic acid and stir at room temperature for 20-30 minutes. Slowly add hydrolysis precursor solution and stir at room temperature for 1-3 hours. Let stand and age for 2-4 hours to obtain modified zirconium oxide sol.

[0022] Furthermore, in step C1, the volume ratio of deionized water to ethanol is 1:3, and the concentration of the nitric acid solution is 5-10 wt%.

[0023] Furthermore, in step C2, the ratio of zirconium propoxide, aluminum isopropoxide, ethanol, glacial acetic acid and hydrolysis precursor solution is 10-12g:0.5-1.5g:15-25mL:1-3mL:3-6mL, and the concentration of glacial acetic acid is ≥99.5wt%.

[0024] The present invention also provides a method for preparing an anti-corrosion refractory material for steel tapping precast components, comprising the following steps:

[0025] S1. Add fused white corundum, sintered corundum, fused aluminum magnesium spinel powder and metallic silicon powder to a mixer, heat the mixer to 40-50℃, and obtain a premix.

[0026] S2. Add the premix to the mixer, add borosilicate synergistic modified phenolic resin for impregnation for 3-5 minutes, add coated modified short fibers, stir for 10-15 minutes, and press-form to obtain an anti-erosion refractory material blank.

[0027] S3. The erosion-resistant refractory material blank is subjected to step solidification to obtain the erosion-resistant refractory material.

[0028] Furthermore, in step S1, the particle size of the fused white corundum is 80-120 mesh, the particle size of the sintered corundum is 120-180 mesh, the particle size of the fused aluminum-magnesium spinel powder is 200-300 mesh, and the particle size of the metallic silicon powder is 300-400 mesh.

[0029] Furthermore, in step S2, the high-pressure molding pressure is 15-25 MPa, the holding time is 5-10 min, and the molding temperature is maintained at 40-50℃.

[0030] Furthermore, in step S3, the step-curing process includes: first holding at 60-80℃ for 2-3 hours, then raising the temperature to 120-150℃ and holding for 3-4 hours, and finally raising the temperature to 220-250℃ and holding for 1-2 hours, with a heating rate of 3-5℃ / min.

[0031] The present invention has the following beneficial effects:

[0032] 1. This invention introduces a borosilicate hybrid resin crosslinking network containing BOC and Si-OC bonds, which works in conjunction with multi-level inorganic aggregates to construct a high-strength and dense skeleton. During its service life, the flexible organosilicon segments effectively release the thermal stress of the matrix, and the borosilicate glass phase generated in situ deeply wets the inorganic phase interface and heals microcracks. The hybrid crosslinking network and the accumulation of dense aggregates block the penetration path of high-temperature molten slag, significantly improving the thermodynamic stability and slag erosion resistance of the erosion-resistant refractory material.

[0033] 2. This invention also prepares zirconium-aluminum composite ceramic-coated carbon fibers, effectively suppressing the lattice stress caused by the high-temperature phase transformation of pure zirconium oxide by utilizing the Zr-Al heterogeneous doping mechanism. The dense ceramic shell not only achieves physical encapsulation of the carbon matrix to isolate oxidation, but also forms a chemical anchor with the borosilicate resin network due to its surface activity. The ceramic interface sealing, combined with the leveling effect of the resin glass phase, not only cuts off the steel erosion channel, but also enhances the high-temperature bridging and pull-out toughening effect of the fibers, thereby improving the thermal shock resistance and high-temperature flexural strength of the corrosion-resistant refractory material.

[0034] 3. This invention also constructs a dense multiphase composite system with three-dimensional interlocking of multi-level inorganic aggregates, metallic silicon powder and modified fibers. During high-temperature service, the antioxidant reaction of metallic silicon powder and the inorganic evolution of borosilicate hybrid network work synergistically to construct a dense non-oxide reinforced interface and multiphase protective layer in situ. This not only optimizes the pore size distribution of the refractory matrix, but also blocks the capillary penetration network of corrosive media through efficient covalent locking between interfaces. Ultimately, this endows the corrosion-resistant refractory material with good mechanical properties and resistance to slag erosion, resulting in comprehensive service durability. Detailed Implementation

[0035] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] The sintered corundum used in this invention was purchased from FUSHIN (Xiamen) Materials Technology Co., Ltd., and has a density of 3.85 g / cm³. 3 The alumina content is 99.2%, and the model number is SR.

[0037] The fused white corundum used in this invention was purchased from Lingshou County Laipeng Mineral Products Business Department. The model number is BGY106, with an alumina content >99% and a density of 3.9 g / cm³. 3 ;

[0038] The fused alumina-magnesia spinel powder used in this invention was purchased from Henan Hengyang Refractory Materials Co., Ltd., with item number 20250818HY, Fe2O3 ≤ 2%, and density 3.3 g / cm³. 3 ;

[0039] The metallic silicon powder used in this invention was purchased from Shandong Hanxinzun New Material Co., Ltd., and its grade is 3303 with Fe≤0.3%, Al≤0.3%, and Ca≤0.03%.

[0040] The paraformaldehyde used in this invention was purchased from Wuhan Jiyesheng Chemical Co., Ltd. It is a white solid powder with a purity of 96% and a molecular weight of (30)N.

[0041] The short-cut carbon fiber used in this invention was purchased from Jiangxi Shuobang New Material Technology Co., Ltd., and has a density of 1.76 g / cm³. 3 The length is 5mm.

[0042] Example 1

[0043] This embodiment provides a method for preparing modified zirconia sol, including the following steps:

[0044] Step I: Preparation of hydrolysis precursor solution

[0045] Weigh 10 mL of deionized water and 30 mL of ethanol and place them in a reaction vessel. Stir and add 5 wt% nitric acid solution to adjust the pH of the system to 2 to obtain the hydrolysis precursor solution.

[0046] Step II: Preparation of modified zirconia sol

[0047] Weigh out 100g of zirconium n-propoxide, 5g of aluminum isopropoxide and 150mL of ethanol and place them in a reaction vessel and stir. Add 1mL of 99.5wt% glacial acetic acid, stir at room temperature for 20min, slowly add 30mL of hydrolysis precursor solution, stir at room temperature for 1h, and let stand for 2h to obtain modified zirconium oxide sol.

[0048] The strong acidic environment provided by nitric acid can catalyze the hydrolysis of metal alkoxides while inhibiting excessive condensation to prevent the formation of bulk precipitation. In the sol preparation stage, glacial acetic acid acts as a chelating agent to coordinate with highly active zirconium propoxide and aluminum isopropoxide, reducing the nucleophilic reactivity of the central metal atom. With the slow addition of acidic precursor solution, zirconium and aluminum alkoxides undergo controlled hydrolysis and dehydration / de-alcoholization condensation to construct a heterogeneous polynuclear inorganic polymer network containing Zr-O-Zr and Zr-O-Al bonds, forming a thermodynamically stable modified zirconium oxide sol.

[0049] Nitric acid-induced low pH environment inhibits heterogeneous condensation of metal alkoxides, endowing the sol with nanoscale dispersion and low viscosity penetration characteristics, ensuring homogeneous coating of precursors on aggregate and fiber surfaces. The Zr-O-Zr and Zr-O-Al inorganic polymer networks constructed by hydrolysis and condensation can be transformed in situ into composite ceramic phases at high temperatures. The volume stress caused by zirconium oxide phase transformation is suppressed through heterogeneous doping mechanism, improving the high-temperature structural stability and thermal shock resistance of the steel outlet preform. At the same time, the dense ceramic interface generated by high-temperature evolution seals the matrix pores, cuts off the penetration path of slag and molten steel, and strengthens the resistance of the refractory system to mechanical erosion and corrosion.

[0050] Example 2

[0051] This embodiment provides a method for preparing modified zirconia sol, including the following steps:

[0052] Step I: Preparation of hydrolysis precursor solution

[0053] Weigh out 10 mL of deionized water and 30 mL of ethanol and place them in a reaction vessel. Stir the mixture and add 7.5 wt% nitric acid solution to adjust the pH of the system to 2.5 to obtain the hydrolysis precursor solution.

[0054] Step II: Preparation of modified zirconia sol

[0055] Weigh out 110g of zirconium n-propoxide, 10g of aluminum isopropoxide and 200mL of ethanol and place them in a reaction vessel and stir. Add 20mL of 99.6wt% glacial acetic acid, stir at room temperature for 25min, slowly add 45mL of hydrolysis precursor solution, stir at room temperature for 2h, and let stand for 3h to obtain modified zirconium oxide sol.

[0056] Example 3

[0057] This embodiment provides a method for preparing modified zirconia sol, including the following steps:

[0058] Step I: Preparation of hydrolysis precursor solution

[0059] Weigh 10 mL of deionized water and 30 mL of ethanol and place them in a reaction vessel. Stir and add 10 wt% nitric acid solution to adjust the pH of the system to 3 to obtain the hydrolysis precursor solution.

[0060] Step II: Preparation of modified zirconia sol

[0061] Weigh out 120g of zirconium n-propoxide, 15g of aluminum isopropoxide and 250mL of ethanol and place them in a reaction vessel and stir. Add 30mL of 99.7wt% glacial acetic acid, stir at room temperature for 30min, slowly add 60mL of hydrolysis precursor solution, stir at room temperature for 3h, and let stand for 4h to obtain modified zirconium oxide sol.

[0062] Example 4

[0063] This embodiment provides a method for preparing coated modified short fibers, including the following steps:

[0064] Step ①: Preparation of pretreated short fibers

[0065] Weigh 400 mL of concentrated nitric acid and place it in a reaction vessel and stir. Add 10 g of chopped carbon fiber. Heat the reaction vessel to 60 °C and keep it at that temperature for 0.5 h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter it, wash the filter cake with deionized water and ethanol until neutral, transfer it to an oven at 50 °C and dry it to constant weight to obtain pretreated short fibers.

[0066] Step 2: Preparation of coated modified short fiber crude product

[0067] The pretreated short fibers were immersed in the modified zirconia sol prepared in Example 1 at a solid-liquid ratio of 1:30. The mixture was stirred and immersed at room temperature for 1 hour. After the reaction was completed, the mixture was filtered and transferred to an oven at 60°C for pre-drying for 1 hour. Then it was transferred to an oven at 60°C for drying for 1 hour to obtain the coated modified short fiber crude product.

[0068] Step 3: Preparation of coated modified short fibers

[0069] The coated modified short fiber crude product was added into a tube furnace under nitrogen atmosphere protection, heated to 600°C at a heating rate of 2°C, held for 2 hours, and then cooled with the furnace to obtain the coated modified short fiber.

[0070] The concentrated nitric acid system breaks the chemical inertness of the carbon fiber surface through liquid-phase oxidation, introducing oxygen-containing functional groups such as carboxyl and hydroxyl groups in situ to increase the surface free energy. During the impregnation stage, the carbon fiber rich in active functional groups induces the adsorption and self-assembly of Zr-O-Al heteropolynuclear inorganic polymer in the sol at the fiber-liquid interface through hydrogen bonding and coordination condensation, forming a gel precursor coating layer. Subsequently, under the protection of nitrogen inert atmosphere, a programmed temperature rise heat treatment is carried out to drive the evaporation of residual solvent in the gel layer, the thermal desorption of organic ligands, and the three-dimensional deep cross-linking of inorganic network. Finally, the phase transformation of the amorphous precursor to a solid zirconium aluminum composite ceramic coating attached to the carbon fiber surface is achieved, resulting in coated modified short fibers.

[0071] Concentrated nitric acid liquid-phase oxidation eliminates the chemical inertness of carbon fibers, and the in-situ introduction of oxygen-containing functional groups increases the surface free energy, providing interfacial chemical anchoring sites for the inorganic phase. During the impregnation stage, hydrogen bonding and coordination induce the sol to self-assemble at the solid-liquid interface, forming a uniform gel layer, which improves the wetting compatibility between the carbon matrix and the inorganic system. Inert atmosphere heat treatment drives the densification, cross-linking, and structural evolution of the gel network. The in-situ constructed dense zirconium-aluminum composite ceramic coating achieves physical encapsulation of carbon fibers. The core-shell modified short fibers are pre-placed in the steel outlet prefabrication, effectively isolating the oxidizing medium during high-temperature service to inhibit carbon component burn-off. At the same time, the high-strength ceramic shell blocks the penetration path of molten slag and steel, and works synergistically with fiber bridging and pull-out effects to enhance the overall refractory system's resistance to mechanical erosion, corrosion, and high-temperature fracture toughness.

[0072] Example 5

[0073] This embodiment provides a method for preparing coated modified short fibers, including the following steps:

[0074] Step ①: Preparation of pretreated short fibers

[0075] Weigh 400 mL of concentrated nitric acid and place it in a reaction vessel and stir. Add 10 g of short-cut carbon fiber. Heat the reaction vessel to 70 °C and keep it at that temperature for 1 h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter it, wash the filter cake with deionized water and ethanol until neutral, transfer it to an oven at 55 °C and dry it to constant weight to obtain pretreated short fibers.

[0076] Step 2: Preparation of coated modified short fiber crude product

[0077] The pretreated short fibers were immersed in the modified zirconia sol prepared in Example 2 at a solid-liquid ratio of 1:31. The mixture was stirred and immersed at room temperature for 1.5 h. After the reaction was completed, the mixture was filtered and transferred to an oven at 65°C for pre-drying for 1.5 h. Then it was transferred to an oven at 70°C for drying for 1.5 h to obtain the coated modified short fiber crude product.

[0078] Step 3: Preparation of coated modified short fibers

[0079] The coated modified short fiber crude product was added into a tube furnace under nitrogen atmosphere protection, heated to 700°C at a heating rate of 3°C, held at that temperature for 2.5 hours, and then cooled with the furnace to obtain the coated modified short fiber.

[0080] Example 6

[0081] This embodiment provides a method for preparing coated modified short fibers, including the following steps:

[0082] Step ①: Preparation of pretreated short fibers

[0083] Weigh 400 mL of concentrated nitric acid and place it in a reaction vessel and stir. Add 10 g of short-cut carbon fiber. Heat the reaction vessel to 80 °C and keep it at that temperature for 1 h. After the reaction is complete, wait for the reaction system to cool to room temperature, filter it, wash the filter cake with deionized water and ethanol until neutral, transfer it to an oven at 60 °C and dry it to constant weight to obtain pretreated short fibers.

[0084] Step 2: Preparation of coated modified short fiber crude product

[0085] The pretreated short fibers were immersed in the modified zirconia sol prepared in Example 3 at a solid-liquid ratio of 1:32. The mixture was stirred and immersed at room temperature for 2 hours. After the reaction was completed, the mixture was filtered and transferred to an oven at 70°C for pre-drying for 2 hours. Then it was transferred to an oven at 80°C for drying for 2 hours to obtain the coated modified short fiber crude product.

[0086] Step 3: Preparation of coated modified short fibers

[0087] The coated modified short fiber crude product was added into a tube furnace under nitrogen atmosphere protection, heated to 800°C at a heating rate of 5°C, held for 3 hours, and then cooled with the furnace to obtain the coated modified short fiber.

[0088] Example 7

[0089] This embodiment provides a method for preparing borosilicate synergistic modified phenolic resin, including the following steps:

[0090] Step (1): Preparation of boron-containing phenolic prepolymer

[0091] Weigh 80g of phenol and place it in a reaction vessel and stir. Add 30g of paraformaldehyde and 2g of barium hydroxide. Heat the reaction vessel to 75℃ and keep it at that temperature for 1 hour. Add 14wt% oxalic acid solution to adjust the pH to 3.5. Add 10g of boric acid and heat the reaction vessel to 90℃. Dehydrate under reduced pressure until the free phenol content is ≤5%. After the reaction is complete, let the reaction system cool to room temperature. Transfer the reaction solution to a rotary evaporator at 55℃ and evaporate under reduced pressure until no solvent is distilled off. Let the remaining material stand and age for 1 hour. Filter to remove trace flocculent impurities. Dry under vacuum at 60℃ to constant weight. After cooling, seal and store to obtain boron-containing phenolic prepolymer.

[0092] Step 2: Preparation of boron-silicon synergistic modified phenolic resin

[0093] Weigh out 160g of boron-containing phenolic prepolymer, 180mL of ethanol, 1mL of deionized water, and 3g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and place them in a nitrogen-protected reactor. Stir the mixture and add triethylamine to adjust the pH to 8. Heat the reactor to 50℃ and maintain the temperature for 2 hours. After the reaction is complete, let the reaction system cool to room temperature and transfer the reaction solution to a rotary evaporator at 55℃. Evaporate under reduced pressure until no solvent is distilled off. Let the remaining material stand and age for 1 hour, filter to remove trace flocculent impurities, and dry under vacuum at 60℃ to constant weight. After cooling, seal and store to obtain boron-silicon synergistic modified phenolic resin.

[0094] Phenol and paraformaldehyde undergo electrophilic addition under alkaline catalysis to generate hydroxymethylphenol. After acid regulation, boric acid undergoes esterification and dehydration condensation with hydroxymethyl or phenolic hydroxyl groups to construct a boron-containing phenolic prepolymer with BOC bonds. In the hybridization modification stage, the methoxy group of the silane coupling agent undergoes partial hydrolysis to generate silanol, which then undergoes dehydration condensation with the residual hydroxyl groups of the prepolymer to form Si-OC bonds. At the same time, its terminal epoxy group undergoes ring-opening addition etherification with the phenolic hydroxyl groups. Through the above multiple covalent bonding reactions, organosilicon segments are grafted in situ onto the boron-containing prepolymer backbone, ultimately constructing a boron-silicon synergistically modified inorganic-organic hybrid resin crosslinking network to obtain a boron-silicon synergistically modified phenolic resin.

[0095] Boric acid enhances the thermodynamic stability and high-temperature carbon residue of the phenolic resin skeleton through esterification and polycondensation of BOC bonds. The boron-oxygen glass phase generated in situ during service can heal microcracks in the matrix and block the penetration of oxidizing media. The silane coupling agent covalently grafts flexible organosilicon segments into the rigid resin network through epoxy ring-opening etherification and methoxy condensation, effectively relieving curing shrinkage stress. It also enhances the interfacial wetting and anchoring force between the binder and inorganic refractory aggregate through Si-OC bonds. This boron-silicon synergistic hybrid crosslinking network undergoes inorganic evolution at high temperature, generating a dense multiphase protective layer, which significantly improves the oxidation resistance and durability of the carbon bond system of the steel tapping precast parts, thereby strengthening the comprehensive structural resistance of the refractory matrix against the mechanical erosion of high-temperature molten steel and the chemical corrosion of slag.

[0096] Example 8

[0097] This embodiment provides a method for preparing borosilicate synergistic modified phenolic resin, including the following steps:

[0098] Step (1): Preparation of boron-containing phenolic prepolymer

[0099] Weigh 90g of phenol and place it in a reaction vessel and stir. Add 40g of paraformaldehyde and 3g of barium hydroxide. Heat the reaction vessel to 80℃ and keep it at that temperature for 1.5h. Add 15wt% oxalic acid solution to adjust the pH to 4. Add 15g of boric acid and heat the reaction vessel to 93℃. Dehydrate under reduced pressure until the free phenol content is ≤5%. After the reaction is complete, wait for the reaction system to cool to room temperature. Transfer the reaction solution to a rotary evaporator at 60℃ and evaporate under reduced pressure until no solvent is distilled off. Let the remaining material stand and age for 1.5h. Filter to remove trace flocculent impurities. Dry under vacuum at 70℃ to constant weight. After cooling, seal and store to obtain boron-containing phenolic prepolymer.

[0100] Step 2: Preparation of boron-silicon synergistic modified phenolic resin

[0101] Weigh out 170g of boron-containing phenolic prepolymer, 190mL of ethanol, 1.2mL of deionized water, and 4g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and place them in a nitrogen-protected reactor. Stir the mixture and add triethylamine to adjust the pH to 8.3. Heat the reactor to 55℃ and maintain the temperature for 3 hours. After the reaction is complete, allow the reaction system to cool to room temperature. Transfer the reaction solution to a rotary evaporator at 60℃ and evaporate under reduced pressure until no solvent is distilled off. Allow the remaining material to stand and age for 1.5 hours. Filter to remove trace amounts of flocculent impurities and dry under vacuum at 70℃ to constant weight. After cooling, seal and store to obtain boron-silicon synergistic modified phenolic resin.

[0102] Example 9

[0103] This embodiment provides a method for preparing borosilicate synergistic modified phenolic resin, including the following steps:

[0104] Step (1): Preparation of boron-containing phenolic prepolymer

[0105] Weigh 100g of phenol and place it in a reaction vessel and stir. Add 50g of paraformaldehyde and 4g of barium hydroxide. Heat the reaction vessel to 85℃ and keep it at that temperature for 2 hours. Add 16wt% oxalic acid solution to adjust the pH to 4.5. Add 20g of boric acid and heat the reaction vessel to 95℃. Dehydrate under reduced pressure until the free phenol content is ≤5%. After the reaction is complete, let the reaction system cool to room temperature. Transfer the reaction solution to a rotary evaporator at 65℃ and evaporate under reduced pressure until no solvent is distilled off. Let the remaining material stand and age for 2 hours. Filter to remove trace flocculent impurities. Dry under vacuum at 80℃ to constant weight. After cooling, seal and store to obtain boron-containing phenolic prepolymer.

[0106] Step 2: Preparation of boron-silicon synergistic modified phenolic resin

[0107] Weigh out 180g of boron-containing phenolic prepolymer, 200mL of ethanol, 1.5mL of deionized water, and 5g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and place them in a nitrogen-protected reactor. Stir the mixture and add triethylamine to adjust the pH to 8.5. Heat the reactor to 60℃ and maintain the temperature for 4 hours. After the reaction is complete, let the reaction system cool to room temperature and transfer the reaction solution to a rotary evaporator at 65℃. Evaporate under reduced pressure until no solvent is distilled off. Let the remaining material stand and age for 2 hours, filter to remove trace amounts of flocculent impurities, and dry under vacuum at 80℃ to constant weight. After cooling, seal and store to obtain boron-silicon synergistic modified phenolic resin.

[0108] Example 10

[0109] This embodiment provides a method for preparing an anti-corrosion refractory material for steel tapping precast components, including the following steps:

[0110] Step 1: Preparation of premix

[0111] Weigh out the following by weight: 50 parts of fused white corundum with a particle size of 80 mesh, 15 parts of sintered corundum with a particle size of 120 mesh, 5 parts of fused aluminum-magnesium spinel powder with a particle size of 200 mesh, and 1 part of metallic silicon powder with a particle size of 300 mesh. Add them to the mixer and heat the mixer to 40°C to obtain the premix.

[0112] Step 2: Preparation of erosion-resistant refractory material blanks

[0113] Weigh out the following by weight: all the premixed material prepared in step one of Example 10 is added to the mixer, 4 parts of the borosilicate synergistic modified phenolic resin prepared in Example 7 are added and impregnated for 3 min, 1 part of the coated modified short fiber prepared in Example 4 is added, stirred for 10 min, and held under pressure at 40℃ and 15MPa for 5 min to obtain the corrosion-resistant refractory material blank.

[0114] Step 3: Preparation of erosion-resistant refractory materials

[0115] The erosion-resistant refractory material blank was added to a forced-air drying oven and first kept at 60℃ for 2 hours. Then, the temperature was increased to 120℃ at a heating rate of 3℃ / min and kept at that temperature for 3 hours. Finally, the temperature was increased to 220℃ at a heating rate of 3℃ / min and kept at that temperature for 1 hour to obtain the erosion-resistant refractory material.

[0116] Corundum, spinel, and metallic silicon powder with different particle size gradients are physically blended to construct a dense inorganic skeleton. During the molding stage, borosilicate-modified phenolic resin undergoes plastic rheology under a hot and pressurized field, wetting the interface between the inorganic aggregate and the coated modified short fiber. After compaction and degassing, a multiphase composite preform is constructed. Subsequent gradient temperature increase drives the binder to undergo thermosetting structural evolution. The low-temperature section promotes the removal of volatiles and resin leveling, while the medium- and high-temperature section induces deep dehydration and polycondensation of active groups in the modified resin, crosslinking to generate a three-dimensional hybrid network. This crosslinked network, through covalent bonding and physical anchoring, locks the aggregate, silicon powder, and reinforcing fiber in situ, completing the curing and molding of the multiphase system into a dense solid refractory structure.

[0117] Multi-grade inorganic aggregates are blended with metallic silicon powder to achieve dense particle packing, optimize the matrix pore size distribution and construct a dense rigid skeleton, thereby improving the system's high-temperature volume stability and resistance to mechanical erosion. A thermal pressure field drives the borosilicate hybrid resin to undergo plastic rheology, and a synergistic degassing and compaction mechanism eliminates micro-pore defects, ensuring homogeneous composite and interfacial wetting of the inorganic phase and modified fibers. Gradient programmed heating controls the smooth removal of volatiles to inhibit microcrack initiation, while inducing deep cross-linking of the binder to generate a three-dimensional hybrid network. This network, through covalent bonding and physical anchoring, locks the multiphase components in situ, strengthening the interfacial bonding force between aggregates, fibers, and the matrix. Ultimately, this results in a corrosion-resistant refractory material for steel taphole precast components with high structural strength, thermal shock resistance, and slag penetration blocking properties.

[0118] Example 11

[0119] This embodiment provides a method for preparing an anti-corrosion refractory material for steel tapping precast components, including the following steps:

[0120] Step 1: Preparation of premix

[0121] Weigh out the following by weight: 55 parts of 100-mesh fused white corundum, 17.5 parts of 150-mesh sintered corundum, 7.5 parts of 250-mesh fused aluminum-magnesium spinel powder, and 2 parts of 350-mesh metallic silicon powder. Add them to the mixer and heat the mixer to 45°C to obtain the premix.

[0122] Step 2: Preparation of erosion-resistant refractory material blanks

[0123] Weigh out the following by weight: all the premixed material prepared in step one of Example 11 is added to the mixer, 5 parts of the borosilicate synergistic modified phenolic resin prepared in Example 8 are added and impregnated for 4 min, 2 parts of the coated modified short fiber prepared in Example 5 are added, stirred for 13 min, and held under pressure at 45℃ and 20MPa for 7 min to obtain the corrosion-resistant refractory material blank.

[0124] Step 3: Preparation of erosion-resistant refractory materials

[0125] The erosion-resistant refractory material blank was added to a forced-air drying oven and first kept at 70℃ for 2.5h. Then, the temperature was increased to 135℃ at a heating rate of 4℃ / min and kept at that temperature for 3.5h. Finally, the temperature was increased to 235℃ at a heating rate of 4℃ / min and kept at that temperature for 1.5h to obtain the erosion-resistant refractory material.

[0126] Example 12

[0127] This embodiment provides a method for preparing an anti-corrosion refractory material for steel tapping precast components, including the following steps:

[0128] Step 1: Preparation of premix

[0129] Weigh out the following by weight: 60 parts of fused white corundum with a particle size of 120 mesh, 20 parts of sintered corundum with a particle size of 180 mesh, 10 parts of fused aluminum-magnesium spinel powder with a particle size of 300 mesh, and 3 parts of metallic silicon powder with a particle size of 400 mesh. Add them to the mixer and heat the mixer to 50°C to obtain the premix.

[0130] Step 2: Preparation of erosion-resistant refractory material blanks

[0131] Weigh out the following by weight: all the premixed material prepared in step one of Example 12 is added to the mixer, 6 parts of the borosilicate synergistic modified phenolic resin prepared in Example 9 are added and impregnated for 5 min, 3 parts of the coated modified short fiber prepared in Example 6 are added, stirred for 15 min, and held under pressure at 50℃ and 25MPa for 10 min to obtain the corrosion-resistant refractory material blank.

[0132] Step 3: Preparation of erosion-resistant refractory materials

[0133] The erosion-resistant refractory material blank is added to a forced-air drying oven and first kept at 80℃ for 3 hours. Then, the temperature is increased to 150℃ at a heating rate of 5℃ / min and kept at that temperature for 4 hours. Finally, the temperature is increased to 250℃ at a heating rate of 5℃ / min and kept at that temperature for 2 hours to obtain the erosion-resistant refractory material.

[0134] Comparative Example 1

[0135] The difference between this comparative example and Example 12 is that aluminum isopropoxide was omitted when preparing the modified zirconia sol in step II.

[0136] Comparative Example 2

[0137] The difference between this comparative example and Example 12 is that, in step two, when preparing the erosion-resistant refractory material blank, an equal amount of commercially available thermosetting phenolic resin is used to replace the coated modified short fibers.

[0138] Comparative Example 3

[0139] The difference between this comparative example and Example 12 is that, in step two, when preparing the erosion-resistant refractory material blank, short-cut carbon fibers are used in an equal amount to replace the borosilicate synergistic modified phenolic resin.

[0140] Performance testing:

[0141] The bulk density and apparent porosity of the erosion-resistant refractory materials prepared in Examples 10-12 and Comparative Examples 1-3 were tested in accordance with the standard GB / T 2997-2015 "Test Methods for Bulk Density, Apparent Porosity and True Porosity of Dense Shaped Refractory Products".

[0142] The room temperature compressive strength of the erosion-resistant refractory materials prepared in Examples 10-12 and Comparative Examples 1-3 was tested in accordance with the standard GB / T 5072-2023 "Test Method for Compressive Strength of Refractory Materials at Room Temperature".

[0143] The high-temperature flexural strength of the erosion-resistant refractory materials prepared in Examples 10-12 and Comparative Examples 1-3 was tested at 1400℃ in accordance with the standard GB / T 3002-2017 "Test Method for High Temperature Flexural Strength of Refractory Materials".

[0144] The thermal shock resistance of the erosion-resistant refractory materials prepared in Examples 10-12 and Comparative Examples 1-3 was tested using the 1100℃ water cooling method in accordance with the standard GB / T 30873-2014 "Test Method for Thermal Shock Resistance of Refractory Materials". The thermal shock resistance was characterized by the number of thermal shock cycles when the sample cracked.

[0145] The slag erosion resistance of the erosion-resistant refractory materials prepared in Examples 10-12 and Comparative Examples 1-3 was tested using the static crucible method in accordance with the standard GB / T 8931-2007 "Test Method for Slag Resistance of Refractory Materials". The erosion resistance was characterized by the percentage of eroded area and the percentage of penetrated area. The specific data are shown in Table 1.

[0146] Table 1 - Performance Test Data for Each Sample

[0147] Project Group Example 10 Example 11 Example 12 Comparative Example 1 Comparative Example 2 Comparative Example 3 <![CDATA[Volume density / (g / cm 3 )]]> 2.92 2.98 2.96 2.70 2.75 2.72 Apparent porosity / % 11.3 10.5 10.9 16.8 15.5 16.2 room temperature pressure resistance / MPa 92.9 93.2 91.5 65.2 70.5 68.8 High temperature flexural strength / MPa 21.4 22.8 22.7 12.5 14.3 13.6 Thermal shock resistance cycles 41 42 42 15 19 17 Percentage of eroded area / % 5.6 4.8 5.1 18.5 15.2 16.8 Percentage of infiltration area / % 4.8 4.0 4.5 16.2 13.5 14.6

[0148] Data Analysis:

[0149] A comparative analysis of the data in the table above shows that the bulk density of the erosion-resistant refractory material prepared by this invention is 2.98 g / cm³. 3 The apparent porosity is 10.5%, the compressive strength at room temperature is 93.2 MPa, the flexural strength at 1400℃ is 22.8 MPa, the thermal shock cycle resistance is 42 cycles, and the erosion area percentage is 4.8% while the penetration area percentage is 4.0%. All of these data are better than the comparative example.

[0150] This invention improves the preparation of modified carbon fiber and borosilicate hybrid phenolic resin for zirconium-aluminum ceramic encapsulation. The modified carbon fiber and borosilicate hybrid phenolic resin are blended with multi-grade inorganic aggregates, and then crosslinked to form a three-dimensional dense multiphase refractory system through hot pressing and gradient temperature curing. This results in an erosion-resistant refractory material, which significantly improves the thermal shock resistance and slag erosion resistance of the erosion-resistant refractory material.

[0151] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A corrosion-resistant refractory material for precast steel taphole components, characterized in that, It comprises the following components by weight: 4-6 parts borosilicate synergistic modified phenolic resin, 1-3 parts coated modified short fiber, 50-60 parts fused white corundum, 15-20 parts sintered corundum, 5-10 parts fused aluminum magnesium spinel powder and 1-3 parts metallic silicon powder. The borosilicate-modified phenolic resin is prepared by the following steps: A1. Place phenol in a reaction vessel and stir. Add paraformaldehyde and barium hydroxide. Heat the reaction vessel to 75-85℃ and keep it at that temperature for 1-2 hours. Add oxalic acid solution to adjust the pH to 3.5-4.

5. Add boric acid. Heat the reaction vessel to 90-95℃ and dehydrate under reduced pressure until the free phenol content is ≤5%. Post-process to obtain boron-containing phenolic prepolymer. A2. Place boron-containing phenolic prepolymer, ethanol, deionized water and 3-(2,3-epoxypropoxy)propyltrimethoxysilane in a reaction vessel under nitrogen atmosphere and stir. Add triethylamine to adjust the pH to 8-8.

5. Heat the reaction vessel to 50-60℃ and keep it at that temperature for 2-4 hours. Post-treatment yields boron-silicon synergistic modified phenolic resin.

2. The corrosion-resistant refractory material for steel tapping precast components according to claim 1, characterized in that, In step A1, the weight ratio of phenol, paraformaldehyde, barium hydroxide, and boric acid is 8-10:3-5:0.2-0.4:1-2, and the concentration of oxalic acid solution is 14-16 wt%; in step A2, the ratio of boron-containing phenolic prepolymer, ethanol, deionized water, and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 16-18 g:18-20 mL:0.1-0.15 mL:0.3-0.5 g.

3. The corrosion-resistant refractory material for steel tapping precast components according to claim 1, characterized in that, The coated and modified short fibers are prepared by the following steps: B1. Place concentrated nitric acid in a reaction vessel and stir. Add short-cut carbon fibers. Heat the reaction vessel to 60-80℃ and keep it at that temperature for 0.5-1h. Then, perform post-treatment to obtain pretreated short fibers. B2. The pretreated short fibers are impregnated in modified zirconia sol and stirred at room temperature for 1-2 hours. The post-treatment yields the coated modified short fiber crude product. B3. Add the coated modified short fiber crude product into a tube furnace under nitrogen atmosphere protection, heat it to 600-800℃ at a heating rate of 2-5℃, hold it at that temperature for 2-3 hours, and then cool it with the furnace to obtain the coated modified short fiber.

4. The corrosion-resistant refractory material for steel tapping precast components according to claim 3, characterized in that, In step B1, the ratio of concentrated nitric acid to chopped carbon fibers is 40 mL: 1 g; in step B2, the solid-liquid ratio of pretreated short fibers to modified zirconium oxide sol is 1:30-32.

5. The corrosion-resistant refractory material for steel tapping precast components according to claim 3, characterized in that, The modified zirconia sol was prepared by the following steps: C1. Place deionized water and ethanol in a reaction vessel and stir. Add nitric acid solution to adjust the pH of the system to 2-3 to obtain the hydrolysis precursor solution. C2. Place zirconium propoxide, aluminum isopropoxide and ethanol in a reaction vessel and stir. Add glacial acetic acid and stir at room temperature for 20-30 minutes. Slowly add hydrolysis precursor solution and stir at room temperature for 1-3 hours. Let stand and age for 2-4 hours to obtain modified zirconium oxide sol.

6. The corrosion-resistant refractory material for steel tapping precast components according to claim 5, characterized in that, In step C1, the volume ratio of deionized water to ethanol is 1:3, and the concentration of nitric acid solution is 5-10 wt%; in step C2, the volume ratio of zirconium propoxide, aluminum isopropoxide, ethanol, glacial acetic acid, and hydrolysis precursor solution is 10-12 g: 0.5-1.5 g: 15-25 mL: 1-3 mL: 3-6 mL, and the concentration of glacial acetic acid is ≥99.5 wt%.

7. A method for preparing an anti-corrosion refractory material for steel tapping precast components as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Add fused white corundum, sintered corundum, fused aluminum magnesium spinel powder and metallic silicon powder to a mixer, heat the mixer to 40-50℃, and obtain a premix. S2. Add the premix to the mixer, add borosilicate synergistic modified phenolic resin for impregnation for 3-5 minutes, add coated modified short fibers, stir for 10-15 minutes, and press-form to obtain an anti-erosion refractory material blank. S3. The erosion-resistant refractory material blank is subjected to step solidification to obtain the erosion-resistant refractory material.