A refractory material with high thermal stability
Through the combination of sodium sulfate and other materials and high-temperature sintering process, the problems of limited thermal storage properties and sodium sulfate leakage of existing refractory heat-resistant materials are solved, and a refractory material with high thermal stability and crack resistance are achieved, and the preparation process is simplified.
Patent Information
- Application Number
- CN202410993620.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-24
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-07-24
AI Technical Summary
The existing refractory heat storage materials have limited heat storage performance in high-temperature environments, and the leakage problem of sodium sulfate needs to be considered during the preparation process, resulting in a small proportion of phase change sodium sulfate, and an additional anti-crack layer is required, which is complicated by the process.
25-30 parts of sodium sulfate, 20-28 parts of silicon carbide, 15-18 parts of alumina, 12-15 parts of aluminum phosphate binder, 5-8 parts of wood fiber, 12-15 parts of graphene oxide, and 3-5 carbon fibers are used. A combination of parts, 10-13 parts of refractory filler, 12-18 parts of expanded perlite and 5-8 parts of zirconium diboride is produced by soaking the expanded perlite in sodium sulfate solution for physical adsorption, combined with high-temperature sintering process Stable structure to improve heat storage and fire resistance, and reinforce crack resistance through wood fibers and carbon fibers.
It significantly improves the heat storage capacity and high thermal stability of the refractory material, avoids sodium sulfate leakage, enhances crack resistance, reduces preparation complexity, and does not require additional crack prevention layer, which extends the service life of the material.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of refractory materials, in particular to a refractory material with high thermal stability. Background Art
[0002] Thermal storage material is a material that can store and release thermal energy. It is widely used in construction, industry, energy storage and other fields. Refractory thermal storage material is a special thermal storage material. It not only has structural stability at high temperatures, but also can absorb and store thermal energy in high temperature environments and release this thermal energy when needed. This type of material is usually used in industrial furnaces, heat exchangers, high-temperature equipment, etc. to improve energy utilization efficiency and save energy. At present, industrial kilns are mostly built with materials such as clay, corundum, mullite, and silicon carbide. These materials have certain refractory properties, but their thermal storage properties are not very good; sodium sulfate is an ideal thermal storage material, and it has low cost, high latent heat density, and stable performance. It can be used to prepare refractory thermal storage materials.
[0003] The Chinese invention patent with the authorization announcement number CN116444281B discloses a sodium sulfate refractory material. By adding sodium sulfate to the refractory layer, the final refractory product has heat storage performance. However, the leakage of sodium sulfate must be considered during the preparation process, so the content of sodium sulfate added in the patent is relatively small. During the preparation process, sodium sulfate is first evenly mixed with silicon carbide and aluminum oxide. Therefore, during high-temperature sintering, sodium sulfate reacts with silicon carbide and aluminum oxide. There is no sodium sulfate that can phase change in the final finished refractory material (or the proportion of sodium sulfate that can phase change is very small). Therefore, although the refractory material provided by the patent has certain heat storage performance, its heat storage performance is limited. In addition, the patent also requires a crack-proof layer to be set outside the refractory layer, and the preparation process is complicated. Summary of the invention
[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a refractory material with high thermal stability, which can fully utilize the phase change heat storage performance of sodium sulfate and greatly improve the heat storage capacity and high thermal stability of the refractory material.
[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:
[0006] A refractory material with high thermal stability comprises the following components by mass: 25-30 parts of sodium sulfate, 20-28 parts of silicon carbide, 15-18 parts of aluminum oxide, 12-15 parts of aluminum phosphate binder, 5-8 parts of wood fiber, 12-15 parts of graphene oxide, 3-5 parts of carbon fiber, 10-13 parts of refractory filler, 12-18 parts of expanded perlite and 5-8 parts of zirconium diboride.
[0007] Furthermore, the particle size of the expanded perlite is 0.2-1 mm.
[0008] Furthermore, the refractory filler is one or more of zinc oxide, magnesium oxide, titanium dioxide, aluminum silicate, wollastonite, and kaolin.
[0009] Furthermore, the preparation method of the refractory material comprises:
[0010] S1: Soaking the expanded perlite in a sodium sulfate solution to obtain expanded perlite adsorbing sodium sulfate;
[0011] S2: zirconium diboride and carbon fiber are mixed, sintered at 1900-2000°C for 1-2 hours, and then crushed into powder after cooling to room temperature to obtain a powdery mixture;
[0012] S3: Evenly mix the expanded perlite adsorbed with sodium sulfate, silicon carbide, aluminum phosphate binder, wood fiber, graphene oxide, and refractory filler, then add the powdered mixture, and finally add the remaining sodium sulfate after soaking the expanded perlite in batches to obtain a mixture;
[0013] S4: Press the mixture into shape, dry it for 24 hours, and then sinter it at high temperature to obtain the finished product.
[0014] Furthermore, the specific process of soaking the expanded perlite in the sodium sulfate solution in step S1 is: heating the sodium sulfate to dissolve, and soaking the expanded perlite in the sodium sulfate solution for 8-10 minutes, filtering, and drying at 50-80°C for 0.5-1h; then soaking the dried expanded perlite in the sodium sulfate solution again, filtering after 8-10 minutes, and drying at 50-80°C for 2-3h, to obtain the expanded perlite adsorbing sodium sulfate.
[0015] Furthermore, the heating rate of high temperature sintering in step S4 is 10° C. / min.
[0016] Furthermore, the specific steps of high temperature sintering in step S4 are: first increase the temperature in the sintering furnace to 800-900°C and keep it warm for 2-3h, naturally cool it down to 100°C, and then increase the temperature to 1000-1100°C and keep it warm for 2-3h; after naturally cooling it down to 800-900°C, increase the temperature to 1300-1400°C and keep it warm for 2-3h, and finally naturally cool it down to 100°C to obtain the finished product.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] (1) In the present invention, the expanded perlite is soaked in a sodium sulfate solution and then dried so that the sodium sulfate is adsorbed in the cavity structure of the expanded perlite. There is no chemical reaction between the sodium sulfate and the expanded perlite, only physical adsorption. The other components are then sintered with the expanded perlite that has adsorbed sodium sulfate. Silicon carbide reacts with sodium sulfate and aluminum oxide to form a stable structure, which covers the expanded perlite that has adsorbed sodium sulfate to prevent leakage of sodium sulfate during the phase change process, so that the final refractory product has excellent heat storage and fire resistance. The refractory material prepared by the present invention itself has excellent crack resistance and high stability, and does not require an additional anti-cracking layer.
[0019] (2) The refractory material provided by the present invention contains wood fibers, which will be carbonized to form tiny pores during the high-temperature sintering process. When the refractory material is in use, the tiny pores can disperse the stress of the refractory material during expansion or contraction, thereby avoiding a large volume change of the refractory material under a heating or cooling environment. When used in combination with carbon fibers, the refractory material can effectively enhance the crack resistance of the refractory material and extend the service life of the refractory material. DETAILED DESCRIPTION
[0020] The present invention is further described below in conjunction with embodiments, and the embodiments of the present invention include but are not limited to the following embodiments.
[0021] The invention provides a refractory material with high thermal stability, comprising 25-30 parts of sodium sulfate, 20-28 parts of silicon carbide, 15-18 parts of aluminum oxide, 12-15 parts of aluminum phosphate binder, 5-8 parts of wood fiber, 12-15 parts of graphene oxide, 3-5 parts of carbon fiber, 10-13 parts of refractory filler, 12-18 parts of expanded perlite, and 5-8 parts of zirconium diboride. The refractory filler is one or more of zinc oxide, magnesium oxide, titanium dioxide, aluminum silicate, wollastonite, and kaolin.
[0022] The method for preparing a refractory material using the above-mentioned material comprises:
[0023] (1) Heat and dissolve sodium sulfate, and soak expanded perlite (particle size 0.2-1 mm) in the sodium sulfate solution. After 8-10 minutes, filter to obtain expanded perlite adsorbed with sodium sulfate;
[0024] (2) Dry the expanded perlite adsorbed with sodium sulfate at 50-80°C for 0.5-1h, soak the dried expanded perlite in sodium sulfate solution again, filter after 8-10min, and dry at 50-80°C for 2-3h;
[0025] (3) Mix zirconium diboride and carbon fiber, sinter at 1900-2000°C for 1-2 hours, and crush into powder after cooling to room temperature;
[0026] (4) Evenly mixing the expanded perlite, silicon carbide, aluminum phosphate binder, wood fiber, graphene oxide, and refractory filler treated with sodium sulfate, adding a powdered zirconium diboride carbon fiber mixture, and finally adding the unused sodium sulfate in batches to obtain a mixture;
[0027] (5) The mixture is pressed into shape, dried for 24 hours, and then sintered at high temperature. The temperature is raised at a rate of 10°C / min to 800-900°C and kept at this temperature for 2-3 hours, then naturally cooled to 100°C, then raised to 1000-1100°C and kept at this temperature for 2-3 hours, then naturally cooled to 800-900°C, then raised to 1300-1400°C and kept at this temperature for 2-3 hours, then naturally cooled to 100°C to obtain the finished product.
[0028] In the present invention, the expanded perlite is soaked in a sodium sulfate solution and then dried, so that the sodium sulfate is adsorbed in the cavity structure of the expanded perlite, and the sodium sulfate and the expanded perlite do not undergo any chemical reaction, but only undergo physical adsorption. Then, other components are sintered with the expanded perlite adsorbing sodium sulfate, and silicon carbide reacts with sodium sulfate and aluminum oxide to generate a stable structure, which covers the expanded perlite adsorbing sodium sulfate, thereby preventing sodium sulfate from leaking during the phase change process, so that the finally prepared refractory material has excellent heat storage and fire resistance.
[0029] The present invention also adds zirconium diboride and carbon fiber. Carbon fiber has excellent corrosion resistance, and zirconium diboride has excellent oxidation resistance. Under high temperature (1900-2000°C), the two will fuse, and zirconium diboride will be dispersed in the grid composed of carbon fiber, thereby increasing the corrosion resistance and oxidation resistance of the refractory material while increasing the density of the refractory material, and further improving the crack resistance of the refractory material. In addition, the present invention also contains wood fiber, which will carbonize to form fine micropores during high-temperature sintering. When the refractory material is in use, the fine micropores can disperse the stress of the refractory material when it expands or contracts, and avoid the refractory material from changing significantly in volume under a heating or cooling environment. The use of the wood fiber and the carbon fiber can further enhance the crack resistance of the refractory material and extend the service life of the refractory material.
[0030] In the process of preparing refractory materials, by controlling the heating rate and using multiple heating methods for sintering, it is possible to effectively avoid reactions between powders to form intermediates, and to avoid deformation of finished products due to excessive heating.
[0031] Example 1
[0032] This embodiment provides a refractory material with high thermal stability, including 25 parts of sodium sulfate, 20 parts of silicon carbide, 15 parts of aluminum oxide, 12 parts of aluminum phosphate binder, 5 parts of wood fiber, 12 parts of graphene oxide, 3 parts of carbon fiber, 10 parts of refractory filler, 12 parts of expanded perlite, and 5 parts of zirconium diboride. The refractory filler is a mixture of zinc oxide, magnesium oxide, and titanium dioxide.
[0033] The method for preparing a refractory material using the above-mentioned material comprises:
[0034] (1) Sodium sulfate was heated and dissolved, and expanded perlite (particle size 1 mm) was immersed in the sodium sulfate solution, and filtered after 8 minutes to obtain expanded perlite adsorbed with sodium sulfate;
[0035] (2) Dry the expanded perlite adsorbed with sodium sulfate at 50°C for 1 hour, soak the dried expanded perlite in sodium sulfate solution again, filter after 8 minutes, and dry at 50°C for 3 hours;
[0036] (3) Mix zirconium diboride and carbon fiber, sinter at 1900°C for 2 hours, and crush into powder after cooling to room temperature;
[0037] (4) Evenly mixing the expanded perlite, silicon carbide, aluminum phosphate binder, wood fiber, graphene oxide, and refractory filler treated with sodium sulfate, adding a powdered zirconium diboride carbon fiber mixture, and finally adding the unused sodium sulfate in batches to obtain a mixture;
[0038] (5) The mixture is pressed into shape, dried for 24 hours, and then sintered at high temperature. The temperature is increased at a rate of 10°C / min to 800°C and kept at this temperature for 3 hours. The temperature is naturally reduced to 100°C. The temperature is then increased to 1000°C and kept at this temperature for 3 hours. The temperature is naturally reduced to 800°C. The temperature is then increased to 1300°C and kept at this temperature for 3 hours. The temperature is then naturally reduced to 100°C to obtain the finished product.
[0039] Example 2
[0040] The present invention provides a refractory material with high thermal stability, comprising 27 parts of sodium sulfate, 24 parts of silicon carbide, 16 parts of aluminum oxide, 13 parts of aluminum phosphate binder, 6 parts of wood fiber, 13 parts of graphene oxide, 4 parts of carbon fiber, 12 parts of refractory filler, 15 parts of expanded perlite, and 7 parts of zirconium diboride. The refractory filler is a mixture of zinc oxide, aluminum silicate, wollastonite, and kaolin.
[0041] The method for preparing a refractory material using the above-mentioned material comprises:
[0042] (1) Sodium sulfate was heated and dissolved, and expanded perlite (particle size 0.5 mm) was immersed in the sodium sulfate solution, and filtered after 9 minutes to obtain expanded perlite adsorbed with sodium sulfate;
[0043] (2) Dry the expanded perlite adsorbed with sodium sulfate at 65°C for 0.8 h, soak the dried expanded perlite in sodium sulfate solution again, filter after 9 min, and dry at 65°C for 2.5 h;
[0044] (3) Mix zirconium diboride and carbon fiber, sinter them at 1950°C for 1.5 hours, and crush them into powder after cooling to room temperature;
[0045] (4) Evenly mixing the expanded perlite, silicon carbide, aluminum phosphate binder, wood fiber, graphene oxide, and refractory filler treated with sodium sulfate, adding a powdered zirconium diboride carbon fiber mixture, and finally adding the unused sodium sulfate in batches to obtain a mixture;
[0046] (5) The mixture is pressed into shape, dried for 24 hours, and then sintered at high temperature. The temperature is increased at a rate of 10°C / min to 850°C and kept at this temperature for 2.5 hours. The temperature is naturally reduced to 100°C. The temperature is then increased to 1050°C and kept at this temperature for 2.5 hours. The temperature is naturally reduced to 850°C. The temperature is then increased to 1350°C and kept at this temperature for 2.5 hours. The temperature is then naturally reduced to 100°C to obtain the finished product.
[0047] The finished products prepared in the above examples 1 and 2 were tested and the results were as follows:
[0048]
[0049] It can be seen from the above table that the refractory material prepared by the present invention has strong latent heat capacity, large compressive strength, and good thermal conductivity. After being used for a long time, no obvious cracks appear.
[0050] The above embodiment is only one of the preferred implementation modes of the present invention and should not be used to limit the protection scope of the present invention. Any changes or modifications that are made to the main design concept and spirit of the present invention and have no substantive significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention.
Claims
1. A refractory material with high thermal stability, characterized in that: The invention is composed of the following components by mass: 25-30 parts of sodium sulfate, 20-28 parts of silicon carbide, 15-18 parts of aluminum oxide, 12-15 parts of aluminum phosphate binder, 5-8 parts of wood fiber, 12-15 parts of graphene oxide, 3-5 parts of carbon fiber, 10-13 parts of refractory filler, 12-18 parts of expanded perlite, and 5-8 parts of zirconium diboride; The preparation method of the refractory material comprises: S1: Soaking the expanded perlite in a sodium sulfate solution to obtain expanded perlite adsorbing sodium sulfate; S2: zirconium diboride and carbon fiber are mixed, sintered at 1900-2000° C. for 1-2 hours, and then crushed into powder after cooling to room temperature to obtain a zirconium diboride carbon fiber powder mixture; S3: Evenly mix the expanded perlite adsorbed with sodium sulfate, silicon carbide, aluminum phosphate binder, wood fiber, graphene oxide, and refractory filler, then add the zirconium diboride carbon fiber powder mixture, and finally add the remaining sodium sulfate after soaking the expanded perlite in batches to obtain a mixture; S4: Press the mixture into shape, dry it for 24 hours, and then sinter it at high temperature to obtain the finished product.
2. A refractory material with high thermal stability according to claim 1, characterized in that: The particle size of expanded perlite is 0.2-1mm.
3. A refractory material with high thermal stability according to claim 2, characterized in that: The refractory filler is one or more of zinc oxide, magnesium oxide, titanium dioxide, aluminum silicate, wollastonite and kaolin.
4. A refractory material with high thermal stability according to claim 1 or 3, characterized in that: The specific process of soaking the expanded perlite in the sodium sulfate solution in step S1 is: heating the sodium sulfate to dissolve, and soaking the expanded perlite in the sodium sulfate solution for 8-10 minutes, filtering, and drying at 50-80°C for 0.5-1h; then soaking the dried expanded perlite in the sodium sulfate solution again, filtering after 8-10 minutes, and drying at 50-80°C for 2-3h, to obtain the expanded perlite adsorbing sodium sulfate.
5. A refractory material with high thermal stability according to claim 4, characterized in that: The heating rate of high temperature sintering in step S4 is 10°C / min.
6. A refractory material with high thermal stability according to claim 5, characterized in that: The specific steps of high temperature sintering in step S4 are: first increase the temperature in the sintering furnace to 800-900°C and keep it warm for 2-3h, naturally cool it down to 100°C, and then increase the temperature to 1000-1100°C and keep it warm for 2-3h; after naturally cooling it down to 800-900°C, increase the temperature to 1300-1400°C and keep it warm for 2-3h, and finally naturally cool it down to 100°C to obtain the finished product.