Thermal shock resistant refractory material for melting furnace and preparation method of thermal shock resistant refractory material

Abstract

The invention relates to the technical field of thermal-shock-resistant refractory materials, and discloses a thermal-shock-resistant refractory material for a melting furnace and a preparation method of the thermal-shock-resistant refractory material. Comprising the following operation steps: step 1, uniformly mixing fused cast fused alumina zirconia, white corundum, aluminum oxide, chromic oxide and modified iron oxide, adding a modified polycarbosilane binder, heating to 250-300 DEG C, and mixing for 20-40 minutes to obtain a mixed material; 2, the mixed material is subjected to hot pressing treatment for 3-4 hours, and a blank is prepared; and sintering at 1600-2000 DEG C for 20-30 hours to obtain the thermal shock resistant refractory material.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal shock resistant refractory materials, in particular to a thermal shock resistant refractory material for a melting furnace and a preparation method thereof. Background Art

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

[0003] In summary, it is of great significance to prepare a thermal shock resistant refractory material for a melting furnace. Summary of the Invention

[0004] The object of the present invention is to provide a thermal shock resistant refractory material for a melting furnace and a preparation method thereof, so as to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

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

[0007] Step 1: uniformly mix fused zirconium corundum, white corundum, aluminum oxide, chromium oxide, and modified iron oxide, add modified polycarbosilane binder, heat to 250-300° C., and mix for 20-40 minutes to obtain a mixed material;

[0008] Step 2: hot pressing the mixed material for 3 to 4 hours to form a billet; sintering the billet at 1600 to 2000° C. for 20 to 30 hours to obtain a thermal shock resistant refractory material.

[0009] More optimally, the raw materials of the mixed material include the following components: by mass, 45 to 65 parts of fused-cast zirconium corundum, 12 to 17 parts of white corundum, 5 to 10 parts of aluminum oxide, 4 to 7 parts of chromium oxide, 2 to 3.5 parts of modified iron oxide, and 3 to 5 parts of modified polycarbosilane binder.

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

[0011] More optimally, 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: 6-7 parts of polycarbosilane, 2-3 parts of vinyl polytitanium silane, and 0.08-0.12 parts of catalyst in parts by mass.

[0012] The more optimized preparation method of the modified iron oxide is as follows: (1) adding iron nitrate nonahydrate and zinc nitrate hexahydrate to deionized water and mixing them uniformly, stirring at 90-95°C for 30-40 minutes, drying, and calcining at 500-550°C for 4-5 hours to obtain ZnO / Fe2O3; (2) adding ZnO / Fe2O3 to ethanol aqueous solution and ultrasonically dispersing, adding KH560, mixing them uniformly, stirring at 50-55°C for 20-24 hours, filtering, washing, and drying to obtain Ep-ZnO / Fe2O3; (3) adding Ep-ZnO / Fe2O3 to ethanol and mixing them uniformly, heating to 55-60°C, adding glutamic acid, stirring for 5-6 hours, washing, drying, and grinding to obtain modified iron oxide.

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

[0014] The more optimized process conditions of the hot pressing treatment are: temperature of 500-630°C, pressure of 200-300 MPa, heating rate of 3-5°C / min, and pressure increase rate of 7-10 MPa / min.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The invention prepares thermal shock resistant refractory material by melting and casting zirconium corundum, white corundum, aluminum oxide, chromium oxide, modified iron oxide and modified polycarbosilane binder;

[0017] Among them, cast zirconium corundum has good thermal stability and can withstand the thermal stress changes generated by the furnace during the heating and cooling process; white corundum 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 corrosion resistance and high-temperature performance.

[0018] In order to further improve the thermal shock resistance and refractory properties of thermal shock resistant refractory materials, in the scheme, active functional groups are introduced on the surface of ZnO / Fe2O3 to obtain 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, and zinc oxide can form a solid solution with aluminum oxide, which is beneficial to improving its density, thereby improving the strength and thermal shock stability of thermal shock resistant refractory materials.

[0019] Traditional binders decompose thermally after high-temperature calcination, generating pores that can affect the thermal shock resistance of thermal shock-resistant refractories. To address this issue, a new approach uses hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane and tetrabutyl titanate to create vinyl polytitanium silane. This vinyl polytitanium silane is then reacted with polycarbosilane under certain conditions to create a modified polycarbosilane.

[0020] In the 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 strengthens the binder's adhesion to the furnace material and reduces the formation of pores. It also helps to reduce thermal stress concentration, allowing the material to withstand greater thermal stress without damage, and can inhibit crack propagation, thereby helping to improve the material's thermal shock resistance.

[0021] During high-temperature sintering, the chemical bonds on tetrabutyl titanate, polycarbosilane, and hydroxyl-terminated vinylmethyl-dimethyl copolysiloxane are broken, thus forming pores;

[0022] In order to reduce the influence of pores, the mixed material is hot pressed at a temperature of 500-630°C and a pressure of 200-300 MPa in the plan to enhance the density of the thermal shock resistant refractory material, thereby improving the thermal shock resistance of the thermal shock resistant refractory material; during the high-temperature sintering process, polycarbosilane is cracked into silicon carbide, and hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane is cracked into silicon dioxide, which can effectively improve the performance of the material; and tetrabutyl titanate will be cracked into titanium dioxide, which can form a solid solution with iron oxide and aluminum oxide in the modified iron oxide under high-temperature sintering, thereby further improving the performance of the thermal shock resistant refractory material. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] In the following specific embodiments, parts are by mass. In this embodiment, it should be noted that the purchase manufacturers of all raw materials involved in the present invention are not subject to any special restrictions. They are exemplarily included: the product number of aluminum oxide is WD1667, purchased from Hubei Wonder Chemical Co., Ltd.; the model of chromium oxide is XH-Cr2O3, purchased from Shanghai Xiaohuang Nano Technology Co., Ltd.; the CAS number of zinc nitrate hexahydrate is 10196-18-6; the CAS number of iron nitrate nonahydrate is 7782-61-8; the product number of polycarbosilane (MW is 1400) is GA8594, purchased from Hubei Guangao Biotechnology Co., Ltd.; the product number of hydroxyl-terminated vinylmethyl-dimethyl copolymer siloxane is GEL-VDS-1013, purchased from Shanghai Mairui Biochemical Technology Co., Ltd.; the CAS number of tetrabutyl titanate is 5593-70-4; the CAS number of KH560 (3-(2,3-epoxypropoxy)propyltrimethoxysilane) is 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: 60 parts of fused-cast zirconium corundum, 12 parts of white corundum, 7 parts of aluminum oxide, 7 parts of chromium oxide, and 2 parts of modified iron oxide were uniformly mixed, 3 parts of modified polycarbosilane binder were added, and the mixture was heated to 280° C. and mixed for 30 minutes to obtain a mixed material;

[0027] Step 2: The mixed material is heated to 600°C at a rate of 4°C / min, and the pressure is increased to 220 MPa at a rate of 8 MPa / min, and hot-pressed for 4 hours to form a billet; the billet is sintered at 1800°C for 28 hours to obtain a thermal shock resistant refractory material;

[0028] The preparation method of the modified polycarbosilane binder is as follows: (1) weighing hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane and tetrabutyl titanate in a mass ratio of 1:1; heating the hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane to 150° C., adding tetrabutyl titanate, and continuing the reaction under vacuum pressure for 2 hours to obtain vinyl polytitanium silane; (2) uniformly mixing 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane, evacuating and introducing nitrogen, adding anhydrous toluene, heating to 75° C., injecting 0.12 parts of Karstedt catalyst, stirring for 24 hours, cooling to room temperature, and evaporating the solvent to obtain the modified polycarbosilane binder;

[0029] The preparation method of modified iron oxide is as follows: (1) adding ferric nitrate nonahydrate and zinc nitrate hexahydrate into deionized water and uniformly mixing them, stirring at 92°C for 30 minutes, drying, and calcining 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) weighing ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; adding ZnO / Fe2O3 into ethanol aqueous solution ( (3) Ep-ZnO / Fe2O3 and glutamic acid were weighed in a mass ratio of 1:0.32; Ep-ZnO / Fe2O3 was added to ethanol and mixed evenly, the mixture was heated to 60°C, glutamic acid was added, the mixture was stirred for 5 hours, washed, dried and ground 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: 65 parts of fused-cast zirconium corundum, 15 parts of white corundum, 10 parts of aluminum oxide, 7 parts of chromium oxide, and 3 parts of modified iron oxide were uniformly mixed, 5 parts of modified polycarbosilane binder were added, and the mixture was heated to 280° C. and mixed for 30 minutes to obtain a mixed material;

[0032] Step 2: The mixed material is heated to 600°C at a rate of 4°C / min, and the pressure is increased to 220 MPa at a rate of 8 MPa / min, and hot-pressed for 4 hours to form a billet; the billet is sintered at 1800°C for 28 hours to obtain a thermal shock resistant refractory material;

[0033] The preparation method of the modified polycarbosilane binder is as follows: (1) weighing hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane and tetrabutyl titanate in a mass ratio of 1:1; heating the hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane to 150° C., adding tetrabutyl titanate, and continuing the reaction under vacuum pressure for 2 hours to obtain vinyl polytitanium silane; (2) uniformly mixing 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane, evacuating and introducing nitrogen, adding anhydrous toluene, heating to 75° C., injecting 0.12 parts of Karstedt catalyst, stirring for 24 hours, cooling to room temperature, and evaporating the solvent to obtain the modified polycarbosilane binder;

[0034] The preparation method of modified iron oxide is as follows: (1) adding ferric nitrate nonahydrate and zinc nitrate hexahydrate into deionized water and uniformly mixing them, stirring at 92°C for 30 minutes, drying, and calcining 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) weighing ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; adding ZnO / Fe2O3 into ethanol aqueous solution ( (3) Ep-ZnO / Fe2O3 and glutamic acid were weighed in a mass ratio of 1:0.32; Ep-ZnO / Fe2O3 was added to ethanol and mixed evenly, the mixture was heated to 60°C, glutamic acid was added, the mixture was stirred for 5 hours, washed, dried and ground 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: 65 parts of fused-cast zirconium corundum, 15 parts of white corundum, 10 parts of aluminum oxide, 7 parts of chromium oxide, and 2 parts of modified iron oxide were uniformly mixed, 3 parts of modified polycarbosilane binder were added, and the mixture was heated to 280° C. and mixed for 30 minutes to obtain a mixed material;

[0037] Step 2: The mixed material is heated to 600°C at a rate of 4°C / min, and the pressure is increased to 220 MPa at a rate of 8 MPa / min, and hot-pressed for 4 hours to form a billet; the billet is sintered at 1800°C for 28 hours to obtain a thermal shock resistant refractory material;

[0038] The preparation method of the modified polycarbosilane binder is as follows: (1) weighing hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane and tetrabutyl titanate in a mass ratio of 1:1; heating the hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane to 150° C., adding tetrabutyl titanate, and continuing the reaction under vacuum pressure for 2 hours to obtain vinyl polytitanium silane; (2) uniformly mixing 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane, evacuating and introducing nitrogen, adding anhydrous toluene, heating to 75° C., injecting 0.12 parts of Karstedt catalyst, stirring for 24 hours, cooling to room temperature, and evaporating the solvent to obtain the modified polycarbosilane binder;

[0039] The preparation method of modified iron oxide is as follows: (1) adding ferric nitrate nonahydrate and zinc nitrate hexahydrate into deionized water and uniformly mixing them, stirring at 92°C for 30 minutes, drying, and calcining 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) weighing ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; adding ZnO / Fe2O3 into ethanol aqueous solution ( (3) Ep-ZnO / Fe2O3 and glutamic acid were weighed in a mass ratio of 1:0.32; Ep-ZnO / Fe2O3 was added to ethanol and mixed evenly, the mixture was heated to 60°C, glutamic acid was added, the mixture was stirred for 5 hours, washed, dried and ground to obtain modified iron oxide.

[0040] Comparative Example 1 is based on Example 2, except that ferric oxide is introduced alone;

[0041] Step 1: 65 parts of fused-cast zirconium corundum, 15 parts of white corundum, 10 parts of aluminum oxide, 7 parts of chromium oxide, and 3 parts of ferric oxide are uniformly mixed, 5 parts of modified polycarbosilane binder are added, and the mixture is heated to 280° C. and kneaded for 30 minutes to obtain a mixed material;

[0042] Step 2: The mixed material is heated to 600°C at a rate of 4°C / min, and the pressure is increased to 220 MPa at a rate of 8 MPa / min, and hot-pressed for 4 hours to form a billet; the billet is sintered at 1800°C for 28 hours to obtain a thermal shock resistant refractory material;

[0043] The preparation method of the modified polycarbosilane adhesive is as follows: (1) weighing hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane and tetrabutyl titanate in a mass ratio of 1:1; heating the hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane to 150°C, adding tetrabutyl titanate, and continuing the reaction under vacuum pressure for 2 hours to obtain vinyl polytitanium silane; (2) uniformly mixing 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane, evacuating and introducing nitrogen, adding anhydrous toluene, heating to 75°C, injecting 0.12 parts of Karstedt catalyst, stirring for 24 hours, cooling to room temperature, and evaporating the solvent to obtain the modified polycarbosilane adhesive.

[0044] Comparative Example 2 is based on Example 2, except that tetrabutyl titanate is introduced into the unmodified polycarbosilane;

[0045] Step 1: 65 parts of fused-cast zirconium corundum, 15 parts of white corundum, 10 parts of aluminum oxide, 7 parts of chromium oxide, and 3 parts of modified iron oxide were uniformly mixed, 5 parts of modified polycarbosilane binder were added, and the mixture was heated to 280° C. and mixed for 30 minutes to obtain a mixed material;

[0046] Step 2: The mixed material is heated to 600°C at a rate of 4°C / min, and the pressure is increased to 220 MPa at a rate of 8 MPa / min, and hot-pressed for 4 hours to form a billet; the billet is sintered at 1800°C for 28 hours to obtain a thermal shock resistant refractory material;

[0047] The preparation method of the modified polycarbosilane binder is as follows: (1) uniformly mixing 7 parts of polycarbosilane and 3 parts of hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane, evacuating the mixture and introducing nitrogen, adding anhydrous toluene, heating the mixture to 75° C., injecting 0.12 parts of Karstedt catalyst, stirring the mixture for 24 hours, cooling the mixture to room temperature, and evaporating the solvent to obtain the modified polycarbosilane binder;

[0048] The preparation method of modified iron oxide is as follows: (1) adding ferric nitrate nonahydrate and zinc nitrate hexahydrate into deionized water and uniformly mixing them, stirring at 92°C for 30 minutes, drying, and calcining 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) weighing ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; adding ZnO / Fe2O3 into ethanol aqueous solution ( (3) Ep-ZnO / Fe2O3 and glutamic acid were weighed in a mass ratio of 1:0.32; Ep-ZnO / Fe2O3 was added to ethanol and mixed evenly, the mixture was heated to 60°C, glutamic acid was added, the mixture was stirred for 5 hours, washed, dried and ground to obtain modified iron oxide.

[0049] Comparative Example 3 was based on Example 2, but without hot pressing treatment;

[0050] Step 1: 65 parts of fused-cast zirconium corundum, 15 parts of white corundum, 10 parts of aluminum oxide, 7 parts of chromium oxide, and 3 parts of modified iron oxide were uniformly mixed, 5 parts of modified polycarbosilane binder were added, and the mixture was heated to 280° C. and mixed for 30 minutes to obtain a mixed material;

[0051] Step 2: The mixed material is pressurized to 220 MPa at a rate of 8 MPa / min and processed for 4 hours to form a billet; the billet is sintered at 1800°C for 28 hours to obtain a thermal shock resistant refractory material;

[0052] The preparation method of the modified polycarbosilane binder is as follows: (1) weighing hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane and tetrabutyl titanate in a mass ratio of 1:1; heating the hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane to 150° C., adding tetrabutyl titanate, and continuing the reaction under vacuum pressure for 2 hours to obtain vinyl polytitanium silane; (2) uniformly mixing 7 parts of polycarbosilane and 3 parts of vinyl polytitanium silane, evacuating and introducing nitrogen, adding anhydrous toluene, heating to 75° C., injecting 0.12 parts of Karstedt catalyst, stirring for 24 hours, cooling to room temperature, and evaporating the solvent to obtain the modified polycarbosilane binder;

[0053] The preparation method of modified iron oxide is as follows: (1) adding ferric nitrate nonahydrate and zinc nitrate hexahydrate into deionized water and uniformly mixing them, stirring at 92°C for 30 minutes, drying, and calcining 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) weighing ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; adding ZnO / Fe2O3 into ethanol aqueous solution ( (3) Ep-ZnO / Fe2O3 and glutamic acid were weighed in a mass ratio of 1:0.32; Ep-ZnO / Fe2O3 was added to ethanol and mixed evenly, the mixture was heated to 60°C, glutamic acid was added, the mixture was stirred for 5 hours, washed, dried and ground 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: 65 parts of fused-cast zirconium corundum, 15 parts of white corundum, 10 parts of aluminum oxide, 7 parts of chromium oxide, and 3 parts of modified iron oxide were uniformly mixed, 5 parts of phenolic resin were added, and the mixture was heated to 280° C. and kneaded for 30 minutes to obtain a mixed material;

[0056] Step 2: The mixed material is heated to 600°C at a rate of 4°C / min, and the pressure is increased to 220 MPa at a rate of 8 MPa / min, and hot-pressed for 4 hours to form a billet; the billet is sintered at 1800°C for 28 hours to obtain a thermal shock resistant refractory material;

[0057] The preparation method of modified iron oxide is as follows: (1) adding ferric nitrate nonahydrate and zinc nitrate hexahydrate into deionized water and uniformly mixing them, stirring at 92°C for 30 minutes, drying, and calcining 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) weighing ZnO / Fe2O3 and KH560 at a mass ratio of 1:0.17; adding ZnO / Fe2O3 into ethanol aqueous solution ( (3) Ep-ZnO / Fe2O3 and glutamic acid were weighed in a mass ratio of 1:0.32; Ep-ZnO / Fe2O3 was added to ethanol and mixed evenly, the mixture was heated to 60°C, glutamic acid was added, the mixture was stirred for 5 hours, washed, dried and ground to obtain modified iron oxide.

[0058] Testing tests: (1) The room temperature compressive strength test of the thermal shock resistant refractory materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 was carried out in accordance with GB / T5072-2008; (2) The thermal shock resistant refractory materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were heated to 900°C, placed in cold water, and subjected to a thermal shock test, and the number of thermal shocks was recorded; (3) The fire resistance test of the thermal shock resistant refractory materials prepared in Examples 1 to 3 was carried out in accordance with GB / T7322-2007.

[0059] Table 1

[0060] Thermal shock resistance (times) Cold 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] Fire resistance (°C) Example 1 2420 Example 2 2580 Example 3 2500

[0063] Conclusion: Comparative Example 1 is based on Example 2, and ferric oxide is introduced alone; this results in a decrease in the performance of the thermal shock resistant refractory material; because the active functional groups on the modified ferric oxide can improve the dispersibility and bonding force between the components, which is beneficial to improving the performance of the thermal shock resistant refractory material; Comparative Example 2 is based on Example 2, and tetrabutyl titanate is introduced into the unmodified polycarbosilane; this results in a decrease in the performance of the thermal shock resistant refractory material, because tetrabutyl titanate will decompose into titanium dioxide during the sintering process, which can form a solid solution with aluminum oxide and iron oxide under high-temperature sintering, which is beneficial to improving the performance of the thermal shock resistant refractory material; Comparative Example 3 is based on Example 2, and no hot pressing treatment is performed; during the sintering process, the chemical bonds of the organic compounds will be broken, resulting in pores, which reduces the performance of the thermal shock resistant refractory material; Comparative Example 4 is based on Example 2, and the modified polycarbosilane is replaced with phenolic resin; this results in a decrease in the performance of the thermal shock resistant 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 embodied 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 illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

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: uniformly mix fused zirconium corundum, white corundum, aluminum oxide, chromium oxide, and modified iron oxide, add modified polycarbosilane binder, heat to 250-300° C., and mix for 20-40 minutes to obtain a mixed material; Step 2: hot pressing the mixed material for 3 to 4 hours to form a billet; sintering the billet at 1600 to 2000° C. for 20 to 30 hours to obtain a thermal shock resistant refractory material.

2. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 1, wherein: The raw materials of the mixed material include the following components: 45-65 parts of fused-cast zirconium corundum, 12-17 parts of white corundum, 5-10 parts of aluminum oxide, 4-7 parts of chromium oxide, 2-3.5 parts of modified iron oxide, and 3-5 parts of modified polycarbosilane binder, calculated by mass.

3. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 1, wherein: The preparation method of the modified polycarbosilane binder is as follows: (1) heating hydroxyl-terminated vinylmethyl-dimethyl copolymerized siloxane to 140-150° C., adding tetrabutyl titanate, and reacting under vacuum pressure for 1.5-2.5 hours to obtain vinyl polytitanium silane; (2) uniformly mixing polycarbosilane and vinyl polytitanium silane, evacuating and introducing nitrogen, adding anhydrous toluene, heating to 70-80° C., injecting a catalyst, stirring for 20-24 hours, cooling to room temperature, and evaporating the solvent to obtain the modified polycarbosilane binder.

4. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 3, wherein: 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: 6-7 parts of polycarbosilane, 2-3 parts of vinyl polytitanium silane, and 0.08-0.12 parts of a catalyst in parts by mass.

5. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 1, wherein: The preparation method of the modified iron oxide is as follows: (1) adding iron nitrate nonahydrate and zinc nitrate hexahydrate into deionized water and uniformly mixing them, stirring at 90-95° C. for 30-40 minutes, drying, and calcining at 500-550° C. for 4-5 hours to obtain ZnO / Fe2O3; (2) adding ZnO / Fe2O3 into an ethanol aqueous solution and ultrasonically dispersing them, adding KH560, uniformly mixing them, stirring at 50-55° C. for 20-24 hours, filtering, washing, and drying to obtain Ep-ZnO / Fe2O3; (3) adding Ep-ZnO / Fe2O3 into ethanol and uniformly mixing them, heating to 55-60° C., adding glutamic acid, stirring for 5-6 hours, washing, drying, and grinding to obtain the modified iron oxide.

6. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 5, characterized in that: The mass ratio of the zinc nitrate hexahydrate to the iron nitrate nonahydrate is 1:(1-3); the mass ratio of the ZnO / Fe2O3 to KH560 is 1:(0.1-0.2); and the mass ratio of the Ep-ZnO / Fe2O3 to glutamic acid is 1:(0.3-0.4).

7. The method for preparing a thermal shock resistant refractory material for a melting furnace according to claim 1, wherein: The process conditions of the hot pressing treatment are: temperature of 500-630° C., pressure of 200-300 MPa, heating rate of 3-5° C. / min, and pressure increasing speed of 7-10 MPa / min.

8. A thermal shock resistant refractory material prepared by the method for preparing a thermal shock resistant refractory material for a melting furnace according to any one of claims 1 to 7.