Thermal shock resistant refractory for fusion furnaces and method for producing the same

Abstract

The application relates to the technical field of anti-thermal-shock refractory materials, and discloses an anti-thermal-shock refractory material for a melting furnace and a preparation method thereof; the preparation method comprises the following operation steps: step 1: uniformly mixing fused cast zirconia corundum, white corundum, alumina, chromium oxide and modified iron oxide, adding a modified polycarbosilane binder, mixing at 250-300 DEG C for 20-40 minutes, and obtaining mixed material; step 2: heat pressing the mixed material for 3-4 hours to prepare a blank; and sintering the blank at 1600-2000 DEG C for 20-30 hours to obtain the anti-thermal-shock refractory material.

Description

Technical Field

[0001] This invention relates to the field of thermal shock refractory materials technology, specifically a thermal shock refractory material for melting furnaces and its preparation method. Background Technology

[0002] With the rapid development of industry, molten furnaces are increasingly widely used in many fields such as metallurgy, chemical industry, and waste treatment. During the operation of molten furnaces, refractory materials need to withstand harsh conditions such as high temperature, slag erosion, mechanical impact, and rapid temperature changes. Among these, thermal shock damage is one of the main causes of refractory material failure. Thermal shock will cause stress concentration inside the refractory material, which will affect the service life of the refractory material and the normal operation of the molten furnace.

[0003] In conclusion, the preparation of a thermal shock resistant refractory material for melting furnaces is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a thermal shock resistant refractory material for melting furnaces and its preparation method, so as to solve the problems raised in the prior art.

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

[0006] A method for preparing a thermal shock resistant refractory material for a melting furnace includes the following steps:

[0007] Step 1: Mix fused cast zirconium alumina, white alumina, alumina, chromium oxide, and modified iron oxide evenly, add modified polycarbosilane binder, heat to 250-300℃ and mix for 20-40 minutes to obtain the mixed material;

[0008] Step 2: Hot-press the mixed materials for 3-4 hours to form a billet; sinter it at 1600-2000℃ for 20-30 hours to obtain a thermal shock refractory material.

[0009] In a more optimized form, the raw materials of the compound material include the following components: by mass parts, 45-65 parts of fused cast zirconium corundum, 12-17 parts of white corundum, 5-10 parts of alumina, 4-7 parts of chromium oxide, 2-3.5 parts of modified iron oxide, and 3-5 parts of modified polycarbosilane binder.

[0010] A more optimized method for preparing the modified polycarbosilane binder is as follows: (1) heating hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane to 140-150°C, adding tetrabutyl titanate, and reacting under vacuum for 1.5-2.5 hours to obtain vinyl polytitanium silane; (2) uniformly mixing polycarbosilane and vinyl polytitanium silane, evacuating and introducing nitrogen gas, adding anhydrous toluene, heating to 70-80°C, injecting catalyst, stirring for 20-24 hours, cooling to room temperature, and evaporating the solvent to obtain the modified polycarbosilane binder.

[0011] In a more optimized manner, the mass ratio of the hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane to tetrabutyl titanate is 1:(1-2); the raw materials of the modified polycarbosilane binder include the following components: by mass parts, 6-7 parts polycarbosilane, 2-3 parts vinyl polytitanium silane, and 0.08-0.12 parts catalyst.

[0012] A more optimized method for preparing the modified iron oxide is as follows: (1) Add ferric nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 90-95°C for 30-40 minutes, dry, and calcine at 500-550°C for 4-5 hours to obtain ZnO / Fe2O3; (2) Add ZnO / Fe2O3 to an ethanol aqueous solution and ultrasonically disperse. Add KH560 and mix evenly. Stir at 50-55°C for 20-24 hours, filter, wash, and dry to obtain Ep-ZnO / Fe2O3; (3) Add Ep-ZnO / Fe2O3 to ethanol and mix evenly. Heat to 55-60°C, add glutamic acid, stir for 5-6 hours, wash, dry, and grind to obtain modified iron oxide.

[0013] More optimized, the mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:(1-3); the mass ratio of ZnO / Fe2O3 to KH560 is 1:(0.1-0.2); and the mass ratio of Ep-ZnO / Fe2O3 to glutamic acid is 1:(0.3-0.4).

[0014] The optimized hot pressing process conditions are: temperature of 500-630℃, pressure of 200-300MPa, heating rate of 3-5℃ / min, and pressurization rate of 7-10MPa / min.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] This invention uses fused cast zirconium corundum, white corundum, alumina, chromium oxide, modified iron oxide, and modified polycarbosilane binder to form a thermal shock refractory material;

[0017] Among them, fused cast zirconia alumina has good thermal stability and can withstand the thermal stress changes generated during the heating and cooling process of the furnace; white fused alumina has high hardness, high melting point and good chemical stability, and can provide high strength in refractory materials; alumina and chromium oxide can improve the material's resistance to erosion and high temperature performance.

[0018] To further improve the thermal shock resistance and refractory properties of thermal shock resistant refractory materials, the proposed method involves introducing active functional groups onto the surface of ZnO / Fe2O3 to prepare modified iron oxide. The active functional groups it contains play a certain dispersing role and can complex with metal oxides, thereby improving the bonding between the components. Furthermore, zinc oxide can form a solid solution with aluminum oxide, which is beneficial to improving its density, thereby enhancing the strength and thermal shock stability of the thermal shock resistant refractory material.

[0019] Traditional binders undergo thermal decomposition after high-temperature calcination, producing pores that affect the thermal shock resistance of thermal shock refractory materials. To address the impact of binders on thermal shock resistance, the proposed solution involves preparing vinyl polytitanium silane using hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane and tetrabutyl titanate. This vinyl polytitanium silane is then combined with polycarbosilane under specific conditions to produce modified polycarbosilane.

[0020] In this scheme, polycarbosilane is a binder with strong thermal and chemical stability; the introduction of hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane and tetrabutyl titanate can form a network structure, which enhances the adhesion of the binder to the furnace material, reduces the formation of pores, and helps to reduce thermal stress concentration, enabling the material to withstand greater thermal stress without damage, inhibiting crack propagation, and thus helping to improve the thermal shock resistance of the material.

[0021] During the high-temperature sintering process, the chemical bonds on tetrabutyl titanate, polycarbosilane, and hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane break, thereby forming pores.

[0022] To reduce the impact of porosity, the proposed method involves hot-pressing the compounded materials at a temperature of 500–630℃ and a pressure of 200–300 MPa to enhance the density of the thermal shock resistant refractories, thereby improving their thermal shock resistance. During high-temperature sintering, polycarbosilane decomposes into silicon carbide, and hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane decomposes into silicon dioxide, effectively improving the material's performance. Furthermore, tetrabutyl titanate decomposes into titanium dioxide, which can react with ferric oxide and alumina in the modified iron oxide to form a solid solution under high-temperature sintering, further enhancing the performance of the thermal shock resistant refractories. Detailed Implementation

[0023] 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.

[0024] In the following specific embodiments, each part refers to a part by weight. In this embodiment, it should be noted that there are no special restrictions on the purchasers of any of the raw materials involved in this invention. Exemplary examples include: alumina with the product number WD1667, purchased from Hubei Wande Chemical Co., Ltd.; chromium oxide with the product number XH-Cr2O3, purchased from Shanghai Xiaohuang Nanotechnology Co., Ltd.; zinc nitrate hexahydrate with the CAS number 10196-18-6; ferric nitrate nonahydrate with the CAS number 7782-61-8; polycarbosilane (MW 1400) with the product number GA8594, purchased from Hubei Guangao Biotechnology Co., Ltd.; hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane with the product number GEL-VDS-1013, purchased from Shanghai Mairui Biochemical Technology Co., Ltd.; tetrabutyl titanate with the CAS number 5593-70-4; and KH560 (3-(2,3-epoxypropoxy)propyltrimethoxysilane) with the CAS number 2530-83-8.

[0025] Example 1: A method for preparing a thermal shock resistant refractory material for a melting furnace, comprising the following steps:

[0026] Step 1: Mix 60 parts of fused cast zirconium corundum, 12 parts of white corundum, 7 parts of alumina, 7 parts of chromium oxide, and 2 parts of modified iron oxide evenly, add 3 parts of modified polycarbosilane binder, heat to 280℃ and knead for 30 minutes to obtain the mixed material.

[0027] Step 2: The mixed material is heated to 600℃ at a rate of 4℃ / min and pressurized to 220MPa at a rate of 8MPa / min. It is hot-pressed for 4 hours to form a billet; it is then sintered at 1800℃ for 28 hours to obtain a thermal shock refractory material.

[0028] The preparation method of the modified polycarbosilane binder is as follows: (1) hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane and tetrabutyl titanate are weighed in a mass ratio of 1:1; the hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane is heated to 150°C, tetrabutyl titanate is added, and the reaction is continued for 2 hours under vacuum pressure to obtain vinyl polytitanium silane; (2) 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane are mixed evenly, nitrogen is introduced under vacuum, anhydrous toluene is added, the mixture is heated to 75°C, 0.12 parts of Karstedt catalyst are injected, the mixture is stirred for 24 hours, cooled to room temperature, and the solvent is evaporated to obtain the modified polycarbosilane binder;

[0029] The preparation method of modified iron oxide is as follows: (1) Add ferric nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 92°C for 30 minutes, dry, and calcine at 550°C for 5 hours to obtain ZnO / Fe2O3; wherein the mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:2; (2) Weigh ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; add ZnO / Fe2O3 to an ethanol aqueous solution ( (3) Disperse Ep-ZnO / Fe2O3 in 65wt% ethanol aqueous solution by ultrasonication, add KH560, mix evenly, stir at 55℃ for 24 hours, filter, wash and dry to obtain Ep-ZnO / Fe2O3; (4) Weigh Ep-ZnO / Fe2O3 and glutamic acid at a mass ratio of 1:0.32; add Ep-ZnO / Fe2O3 to ethanol and mix evenly, heat to 60℃, add glutamic acid, stir for 5 hours, wash, dry and grind to obtain modified iron oxide.

[0030] Example 2: A method for preparing a thermal shock resistant refractory material for a melting furnace, comprising the following steps:

[0031] Step 1: Mix 65 parts of fused cast zirconium corundum, 15 parts of white corundum, 10 parts of alumina, 7 parts of chromium oxide, and 3 parts of modified iron oxide evenly, add 5 parts of modified polycarbosilane binder, heat to 280℃ and knead for 30 minutes to obtain the mixed material.

[0032] Step 2: The mixed material is heated to 600℃ at a rate of 4℃ / min and pressurized to 220MPa at a rate of 8MPa / min. It is hot-pressed for 4 hours to form a billet; it is then sintered at 1800℃ for 28 hours to obtain a thermal shock refractory material.

[0033] The preparation method of the modified polycarbosilane binder is as follows: (1) hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane and tetrabutyl titanate are weighed in a mass ratio of 1:1; the hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane is heated to 150°C, tetrabutyl titanate is added, and the reaction is continued for 2 hours under vacuum pressure to obtain vinyl polytitanium silane; (2) 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane are mixed evenly, nitrogen is introduced under vacuum, anhydrous toluene is added, the mixture is heated to 75°C, 0.12 parts of Karstedt catalyst are injected, the mixture is stirred for 24 hours, cooled to room temperature, and the solvent is evaporated to obtain the modified polycarbosilane binder;

[0034] The preparation method of modified iron oxide is as follows: (1) Add ferric nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 92°C for 30 minutes, dry, and calcine at 550°C for 5 hours to obtain ZnO / Fe2O3; wherein the mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:2; (2) Weigh ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; add ZnO / Fe2O3 to an ethanol aqueous solution ( (3) Disperse Ep-ZnO / Fe2O3 in 65wt% ethanol aqueous solution by ultrasonication, add KH560, mix evenly, stir at 55℃ for 24 hours, filter, wash and dry to obtain Ep-ZnO / Fe2O3; (4) Weigh Ep-ZnO / Fe2O3 and glutamic acid at a mass ratio of 1:0.32; add Ep-ZnO / Fe2O3 to ethanol and mix evenly, heat to 60℃, add glutamic acid, stir for 5 hours, wash, dry and grind to obtain modified iron oxide.

[0035] Example 3: A method for preparing a thermal shock resistant refractory material for a melting furnace, comprising the following steps:

[0036] Step 1: Mix 65 parts of fused cast zirconium corundum, 15 parts of white corundum, 10 parts of alumina, 7 parts of chromium oxide, and 2 parts of modified iron oxide evenly, add 3 parts of modified polycarbosilane binder, heat to 280℃ and knead for 30 minutes to obtain the mixed material.

[0037] Step 2: The mixed material is heated to 600℃ at a rate of 4℃ / min and pressurized to 220MPa at a rate of 8MPa / min. It is hot-pressed for 4 hours to form a billet; it is then sintered at 1800℃ for 28 hours to obtain a thermal shock refractory material.

[0038] The preparation method of the modified polycarbosilane binder is as follows: (1) hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane and tetrabutyl titanate are weighed in a mass ratio of 1:1; the hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane is heated to 150°C, tetrabutyl titanate is added, and the reaction is continued for 2 hours under vacuum pressure to obtain vinyl polytitanium silane; (2) 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane are mixed evenly, nitrogen is introduced under vacuum, anhydrous toluene is added, the mixture is heated to 75°C, 0.12 parts of Karstedt catalyst are injected, the mixture is stirred for 24 hours, cooled to room temperature, and the solvent is evaporated to obtain the modified polycarbosilane binder;

[0039] The preparation method of modified iron oxide is as follows: (1) Add ferric nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 92°C for 30 minutes, dry, and calcine at 550°C for 5 hours to obtain ZnO / Fe2O3; wherein the mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:2; (2) Weigh ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; add ZnO / Fe2O3 to an ethanol aqueous solution ( (3) Disperse Ep-ZnO / Fe2O3 in 65wt% ethanol aqueous solution by ultrasonication, add KH560, mix evenly, stir at 55℃ for 24 hours, filter, wash and dry to obtain Ep-ZnO / Fe2O3; (4) Weigh Ep-ZnO / Fe2O3 and glutamic acid at a mass ratio of 1:0.32; add Ep-ZnO / Fe2O3 to ethanol and mix evenly, heat to 60℃, add glutamic acid, stir for 5 hours, wash, dry and grind to obtain modified iron oxide.

[0040] Comparative Example 1 is based on Example 2, but introduces ferric oxide alone;

[0041] Step 1: Mix 65 parts of fused cast zirconium corundum, 15 parts of white corundum, 10 parts of alumina, 7 parts of chromium oxide, and 3 parts of ferric oxide evenly, add 5 parts of modified polycarbosilane binder, heat to 280℃ and knead for 30 minutes to obtain the mixed material.

[0042] Step 2: The mixed material is heated to 600℃ at a rate of 4℃ / min and pressurized to 220MPa at a rate of 8MPa / min. It is hot-pressed for 4 hours to form a billet; it is then sintered at 1800℃ for 28 hours to obtain a thermal shock refractory material.

[0043] The preparation method of the modified polycarbosilane binder is as follows: (1) Weigh hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane and tetrabutyl titanate in a mass ratio of 1:1; heat the hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane to 150°C, add tetrabutyl titanate, and continue to react under vacuum for 2 hours to obtain vinyl polytitanium silane; (2) Mix 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane evenly, evacuate and introduce nitrogen, add anhydrous toluene, heat to 75°C, inject 0.12 parts of Karstedt catalyst, stir for 24 hours, cool to room temperature, evaporate the solvent, and obtain the modified polycarbosilane binder.

[0044] Comparative Example 2 is based on Example 2, with the introduction of tetrabutyl titanate into unmodified polycarbosilane;

[0045] Step 1: Mix 65 parts of fused cast zirconium corundum, 15 parts of white corundum, 10 parts of alumina, 7 parts of chromium oxide, and 3 parts of modified iron oxide evenly, add 5 parts of modified polycarbosilane binder, heat to 280℃ and knead for 30 minutes to obtain the mixed material.

[0046] Step 2: The mixed material is heated to 600℃ at a rate of 4℃ / min and pressurized to 220MPa at a rate of 8MPa / min. It is hot-pressed for 4 hours to form a billet; it is then sintered at 1800℃ for 28 hours to obtain a thermal shock refractory material.

[0047] The preparation method of the modified polycarbosilane binder is as follows: (1) 7 parts of polycarbosilane and 3 parts of hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane are mixed evenly, nitrogen is introduced under vacuum, anhydrous toluene is added, heated to 75°C, 0.12 parts of Karstedt catalyst are injected, stirred for 24 hours, cooled to room temperature, and the solvent is evaporated to obtain the modified polycarbosilane binder;

[0048] The preparation method of modified iron oxide is as follows: (1) Add ferric nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 92°C for 30 minutes, dry, and calcine at 550°C for 5 hours to obtain ZnO / Fe2O3; wherein the mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:2; (2) Weigh ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; add ZnO / Fe2O3 to an ethanol aqueous solution ( (3) Disperse Ep-ZnO / Fe2O3 in 65wt% ethanol aqueous solution by ultrasonication, add KH560, mix evenly, stir at 55℃ for 24 hours, filter, wash and dry to obtain Ep-ZnO / Fe2O3; (4) Weigh Ep-ZnO / Fe2O3 and glutamic acid at a mass ratio of 1:0.32; add Ep-ZnO / Fe2O3 to ethanol and mix evenly, heat to 60℃, add glutamic acid, stir for 5 hours, wash, dry and grind to obtain modified iron oxide.

[0049] Comparative Example 3 is based on Example 2, but without hot pressing.

[0050] Step 1: Mix 65 parts of fused cast zirconium corundum, 15 parts of white corundum, 10 parts of alumina, 7 parts of chromium oxide, and 3 parts of modified iron oxide evenly, add 5 parts of modified polycarbosilane binder, heat to 280℃ and knead for 30 minutes to obtain the mixed material.

[0051] Step 2: Pressurize the compound material to 220 MPa at a rate of 8 MPa / min and process for 4 hours to form a billet; sinter it at 1800℃ for 28 hours to obtain a thermal shock refractory material.

[0052] The preparation method of the modified polycarbosilane binder is as follows: (1) hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane and tetrabutyl titanate are weighed in a mass ratio of 1:1; the hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane is heated to 150°C, tetrabutyl titanate is added, and the reaction is continued for 2 hours under vacuum pressure to obtain vinyl polytitanium silane; (2) 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane are mixed evenly, nitrogen is introduced under vacuum, anhydrous toluene is added, the mixture is heated to 75°C, 0.12 parts of Karstedt catalyst are injected, the mixture is stirred for 24 hours, cooled to room temperature, and the solvent is evaporated to obtain the modified polycarbosilane binder;

[0053] The preparation method of modified iron oxide is as follows: (1) Add ferric nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 92°C for 30 minutes, dry, and calcine at 550°C for 5 hours to obtain ZnO / Fe2O3; wherein the mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:2; (2) Weigh ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; add ZnO / Fe2O3 to an ethanol aqueous solution ( (3) Disperse Ep-ZnO / Fe2O3 in 65wt% ethanol aqueous solution by ultrasonication, add KH560, mix evenly, stir at 55℃ for 24 hours, filter, wash and dry to obtain Ep-ZnO / Fe2O3; (4) Weigh Ep-ZnO / Fe2O3 and glutamic acid at a mass ratio of 1:0.32; add Ep-ZnO / Fe2O3 to ethanol and mix evenly, heat to 60℃, add glutamic acid, stir for 5 hours, wash, dry and grind to obtain modified iron oxide.

[0054] Comparative Example 4 is based on Example 2, except that the modified polycarbosilane is replaced with phenolic resin;

[0055] Step 1: Mix 65 parts of fused cast zirconium corundum, 15 parts of white corundum, 10 parts of alumina, 7 parts of chromium oxide, and 3 parts of modified iron oxide evenly, add 5 parts of phenolic resin, heat to 280℃ and knead for 30 minutes to obtain the mixed material.

[0056] Step 2: The mixed material is heated to 600℃ at a rate of 4℃ / min and pressurized to 220MPa at a rate of 8MPa / min. It is hot-pressed for 4 hours to form a billet; it is then sintered at 1800℃ for 28 hours to obtain a thermal shock refractory material.

[0057] The preparation method of modified iron oxide is as follows: (1) Add ferric nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 92°C for 30 minutes, dry, and calcine at 550°C for 5 hours to obtain ZnO / Fe2O3; wherein the mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:2; (2) Weigh ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; add ZnO / Fe2O3 to an ethanol aqueous solution ( (3) Disperse Ep-ZnO / Fe2O3 in 65wt% ethanol aqueous solution by ultrasonication, add KH560, mix evenly, stir at 55℃ for 24 hours, filter, wash and dry to obtain Ep-ZnO / Fe2O3; (4) Weigh Ep-ZnO / Fe2O3 and glutamic acid at a mass ratio of 1:0.32; add Ep-ZnO / Fe2O3 to ethanol and mix evenly, heat to 60℃, add glutamic acid, stir for 5 hours, wash, dry and grind to obtain modified iron oxide.

[0058] Tests: (1) The room temperature compressive strength of the thermal shock refractory materials prepared in Examples 1-3 and Comparative Examples 1-4 was tested according to GB / T5072-2008; (2) The thermal shock refractory materials prepared in Examples 1-3 and Comparative Examples 1-4 were heated to 900℃ and then placed in cold water for thermal shock resistance test, and the number of thermal shock tests was recorded; (3) The fire resistance of the thermal shock refractory materials prepared in Examples 1-3 was tested according to GB / T7322-2007.

[0059] Table 1

[0060] Thermal shock resistance (number of times) room temperature pressure resistance (MPa) Example 1 48 146 Example 2 56 154 Example 3 53 151 Comparative Example 1 42 138 Comparative Example 2 45 143 Comparative Example 3 33 127 Comparative Example 4 37 135

[0061] Table 2

[0062] Refractoriness (°C) Example 1 2420 Example 2 2580 Example 3 2500

[0063] Conclusions: Comparative Example 1, based on Example 2, introduced ferric oxide alone, leading to a decrease in the performance of the thermal shock refractory material. This is because the active functional groups on the modified ferric oxide can improve the dispersibility and binding force between components, thus improving the performance of the thermal shock refractory material. Comparative Example 2, based on Example 2, introduced tetrabutyl titanate into the unmodified polycarbosilane, leading to a decrease in the performance of the thermal shock refractory material. This is because tetrabutyl titanate decomposes into titanium dioxide during sintering, which can form a solid solution with alumina and ferric oxide at high temperatures, thus improving the performance of the thermal shock refractory material. Comparative Example 3, based on Example 2, did not undergo hot pressing treatment, resulting in the breakage of chemical bonds in the organic compounds during sintering, generating pores and reducing the performance of the thermal shock refractory material. Comparative Example 4, based on Example 2, replaced the modified polycarbosilane with phenolic resin, leading to a decrease in the performance of the thermal shock refractory material.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a thermal shock resistant refractory material for a melting furnace, characterized in that: The following steps are included: Step 1: Mix 45-65 parts of fused cast zirconium corundum, 12-17 parts of white corundum, 5-10 parts of alumina, 4-7 parts of chromium oxide, and 2-3.5 parts of modified iron oxide evenly, add 3-5 parts of modified polycarbosilane binder, heat to 250-300℃ and knead for 20-40 minutes to obtain the mixed material; Step 2: Hot-press the mixed materials for 3-4 hours to form a billet; sinter it at 1600-2000℃ for 20-30 hours to obtain a thermal shock refractory material; The modified polycarbosilane binder is prepared as follows: (1) hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane is heated to 140~150℃, tetrabutyl titanate is added, and the reaction is carried out under vacuum for 1.5~2.5 hours to obtain vinyl polytitanium silane; (2) polycarbosilane and vinyl polytitanium silane are mixed evenly, nitrogen is introduced under vacuum, anhydrous toluene is added, the mixture is heated to 70~80℃, a catalyst is injected, the mixture is stirred for 20~24 hours, cooled to room temperature, and the solvent is evaporated to obtain the modified polycarbosilane binder; The modified iron oxide is prepared as follows: (1) Add iron nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mix evenly. Stir at 90~95℃ for 30~40 minutes, dry, and calcine at 500~550℃ for 4~5 hours to obtain ZnO / Fe2O3; (2) Add ZnO / Fe2O3 to an ethanol aqueous solution and ultrasonically disperse. Add KH560 and mix evenly. Stir at 50~55℃ for 20~24 hours, filter, wash, and dry to obtain Ep-ZnO / Fe2O3; (3) Add Ep-ZnO / Fe2O3 to ethanol and mix evenly. Heat to 55~60℃, add glutamic acid, stir for 5~6 hours, wash, dry, and grind to obtain modified iron oxide.

2. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 1, characterized in that: The mass ratio of the hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane to tetrabutyl titanate is 1:(1~2); the raw materials of the modified polycarbosilane binder include the following components: by mass, 6~7 parts polycarbosilane, 2~3 parts vinyl polytitanium silane, and 0.08~0.12 parts catalyst.

3. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 1, characterized in that: The mass ratio of zinc nitrate hexahydrate to ferric nitrate nonahydrate is 1:(1~3); the mass ratio of ZnO / Fe2O3 to KH560 is 1:(0.1~0.2); and the mass ratio of Ep-ZnO / Fe2O3 to glutamic acid is 1:(0.3~0.4).

4. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 1, characterized in that: The hot pressing process conditions are as follows: temperature 500~630℃, pressure 200~300MPa, heating rate 3~5℃ / min, and pressurization rate 7~10MPa / min.

5. The thermal shock refractory material is prepared by the method for preparing a thermal shock refractory material for a melting furnace according to any one of claims 1 to 4.