A rare earth additive modified thermal storage body casting material and preparation method thereof
By using rare earth additives to modify the heat storage castable in the lining materials of industrial kilns, a new crystal phase is generated through high-temperature sintering reaction, the problem of insufficient performance of existing materials is solved, and the effect of improving bulk density, flexural strength and heat storage rate is achieved, achieving the purpose of energy conservation and emission reduction.
Patent Information
- Application Number
- CN202411931268.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-04-01
AI Technical Summary
The volume density, thermal conductivity and thermal storage rate of existing industrial kiln lining materials need to be improved.
The heat-reserving body castable is modified with rare earth additives. By mixing lanthanum cerium oxide, yttrium-rich rare earth oxide, α-activated alumina and solid waste silicon powder in a specific proportion, it is added to the castable as a rare earth modification additive, and a new crystal phase is generated through high-temperature sintering reaction to improve the density and heat storage rate of the material.
The volume density, flexural strength, compressive strength and heat storage rate of the castable are improved, the porosity and thermal conductivity are reduced, the energy-saving and emission reduction effect is achieved, the production costs of enterprises are reduced, and a new way for the resource utilization of solid waste silicon fume is provided.
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Figure CN119735446A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of industrial furnace castables, and in particular relates to a rare earth additive modified heat storage body castable and a preparation method thereof. Background Art
[0002] Industrial furnaces refer to thermal equipment that uses the heat generated by fuel combustion or electrical energy conversion in industrial production to smelt, melt, roast (calcine), heat, dry distill, gasify, etc. materials or workpieces. Industrial furnaces are widely used in steel, coking, nonferrous metals, building materials, petrochemicals, chemicals, machinery manufacturing and other industries, and play an important supporting role in industrial development.
[0003] Refractory castable is an amorphous material, mainly a mixture of aggregate, fine powder, micro powder and some additives and binders. It is used as lining material for industrial kilns. It has the characteristics of high temperature resistance, corrosion resistance and wear resistance. It is widely used in metallurgy, building materials, steel, chemical industry and other industries.
[0004] At present, the volume density, thermal conductivity and heat storage rate of the castables used for industrial kiln linings need to be further improved. Summary of the invention
[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a rare earth additive modified thermal storage body castable and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.
[0006] In order to solve the above technical problems, the technical solution specifically adopted by the present invention is:
[0007] The first aspect of the present invention provides a rare earth additive modified thermal storage body castable, comprising the following raw materials in parts by weight: 10 to 30 parts of 5 to 8 mm high alumina bauxite, 10 to 25 parts of 3 to 5 mm high alumina bauxite, 15 to 35 parts of 1 to 3 mm high alumina bauxite, 10 to 30 parts of 0 to 1 mm plate-shaped corundum, 7 to 20 parts of 200 mesh plate-shaped corundum, 10 to 20 parts of 325 mesh plate-shaped corundum, 2 to 5 parts of solid waste silicon powder, 2 to 5 parts of clay, 1 to 5 parts of rare earth modified additives, 5 to 10 parts of aluminate cement, 0.1 to 0.3 parts of explosion-proof fiber, 0.05 to 0.2 parts of water reducer and 0.05 to 0.2 parts of dispersant.
[0008] As a further illustration of the present invention, the rare earth modification aid is a mixture of lanthanum cerium oxide, yttrium-rich rare earth oxide, α-activated alumina and solid waste silicon powder.
[0009] As a further illustration of the present invention, the mass proportions of lanthanum cerium oxide, yttrium-rich rare earth oxide, α-activated alumina and solid waste silicon micropowder in the rare earth modification additive are 76.5%, 13.5%, 7.2% and 2.8% respectively.
[0010] As a further illustration of the present invention, the preparation process of the rare earth modification additive includes:
[0011] The lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a blast drying oven, dried at 110° C. for 24 hours, and then the dried lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a muffle furnace, heated from room temperature to 1000° C. for 180 minutes, and then kept at 1000° C. for 6 hours for calcination, and the calcined powders are ball-milled appropriately, and then sieved through a 200-mesh sieve, with a sieve residue of less than 3%, to obtain lanthanum cerium oxide and yttrium-rich rare earth oxide, which are packaged for later use;
[0012] The obtained lanthanum cerium oxide and yttrium-rich rare earth oxide are mixed with α-activated alumina and solid waste silicon powder, wet-milled for 12 hours, and then the slurry is dried at 110°C to 150°C. After drying, the powder is ground and passed through a 200-mesh sieve with a sieve residue of less than 3% to obtain a rare earth modification additive, which is packaged for later use.
[0013] As a further illustration of the present invention, the clay is a mixture of Guangxi white mud and Shuozhou soil; the aluminate cement is a mixture of CA70 and CA80; the water reducer is FDN high-efficiency water reducer; and the dispersant is sodium hexametaphosphate.
[0014] The second aspect of the present invention provides a method for preparing the rare earth additive modified thermal storage body castable, comprising the following steps:
[0015] S1. Ingredients: According to the weight ratio described in any one of the above, high-alumina bauxite, plate-shaped corundum, solid waste silicon powder, clay, rare earth modification additive, aluminate cement, explosion-proof fiber, water reducer and dispersant are weighed respectively;
[0016] S2. Mixing raw materials: Stirring and mixing the ingredients prepared in step S1 to obtain a mixed material, and then adding water to the mixed material and stirring and mixing to obtain a viscous rare earth additive modified thermal storage body casting material.
[0017] As a further illustration of the present invention, the mixing process of the mixed material in step S2 is specifically as follows: first, the aggregate consisting of 5-8 mm high alumina bauxite, 3-5 mm high alumina bauxite, 1-3 mm high alumina bauxite and 0-1 mm plate-shaped corundum is put into a mixer and stirred for 2 minutes, and then 200 mesh plate-shaped corundum, 325 mesh plate-shaped corundum, solid waste silicon micropowder, clay and aluminate cement are added and the fine powder is continued to be stirred for 3 minutes, and finally, rare earth modified additives, explosion-proof fibers, high-efficiency water reducers and dispersants are added and stirred for 2 minutes until the material powder is evenly stirred.
[0018] As a further explanation of the present invention, in step S2, when adding water to the mixed material, water is added while stirring, and the state of the material is observed. The total amount of water added is 4-6% of the final castable, and the stirring time for adding water is 3 minutes, until the mixture is stirred and mixed and has viscosity.
[0019] As a further illustration of the present invention, the preparation method further comprises:
[0020] S3, molding: injecting the casting material obtained in step S2 into the mold, shaking to remove bubbles and compacting the material;
[0021] S4, curing and firing: the material obtained in step 3 is naturally cured for 12 to 24 hours and then demolded, and then the sample strip is dried and calcined at high temperature to obtain a rare earth additive modified thermal storage body casting material sample block.
[0022] As a further explanation of the present invention, step S4 is specifically: placing the material obtained in step 3 into a 110°C forced air drying oven and drying it for 24 hours. After baking, take out the sample and place it in a muffle furnace. From room temperature to 1000°C, heat up for 170 minutes, and keep it at 1000°C for 30 minutes; from 1000°C to 1450°C, heat up for 150 minutes, and keep it at 1450°C for 3 hours. As the furnace temperature naturally cools to room temperature, take it out to obtain a rare earth additive modified thermal storage body castable sample.
[0023] Compared with the prior art, the present invention has the following technical effects:
[0024] 1. Rare earth additives are used to improve the heat storage capacity of castables, reduce the energy consumption of industrial kilns, improve energy utilization, achieve energy conservation and emission reduction effects, and thus reduce enterprise production costs.
[0025] 2. It provides a new way for the resource utilization of solid waste silica fume. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 The present invention provides a flow chart of a method for preparing a rare earth additive modified thermal storage body castable. DETAILED DESCRIPTION
[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.
[0028] The invention mainly uses a mixture of lanthanum-cerium rare earth oxide and yttrium-rich rare earth oxide, and then wet-ball mills with alpha-active alumina and solid waste silicon micropowder in proportion, sieves after drying, and adds the mixture to a castable with high-alumina bauxite as the main material. By utilizing the chemical properties of the rare earth element such as the unique electronic layer structure, chemical activity and large ion radius, the rare earth element is prompted to react with SiO2 in the refractory castable after high-temperature sintering to generate new components (LaCe)2·2SiO2, La2O3·SiO2, Y2O3·SiO2 or Ho2O3·SiO2, which is beneficial to mullite formation, promotes the growth and development of crystal phases such as mullite (3Al2O3·2SiO2), improves the crystallinity of phase change products, promotes sintering of the refractory castable, reduces the sintering temperature, improves the density and compressive strength of the refractory castable, reduces the porosity and thermal conductivity, and thus improves the heat storage rate of the material, thereby achieving the purpose of energy saving rate.
[0029] Specifically, the present invention provides a rare earth additive modified thermal storage body castable, comprising the following raw materials in parts by weight: 10 to 30 parts of 5 to 8 mm high alumina bauxite, 10 to 25 parts of 3 to 5 mm high alumina bauxite, 15 to 35 parts of 1 to 3 mm high alumina bauxite, 10 to 30 parts of 0 to 1 mm plate-shaped corundum, 7 to 20 parts of 200 mesh plate-shaped corundum, 10 to 20 parts of 325 mesh plate-shaped corundum, 2 to 5 parts of solid waste silicon micropowder, 2 to 5 parts of clay, 1 to 5 parts of rare earth modified additives, 5 to 10 parts of aluminate cement, 0.1 to 0.3 parts of explosion-proof fiber, 0.05 to 0.2 parts of high-efficiency water reducer and 0.05 to 0.2 parts of dispersant.
[0030] Specifically, the above-mentioned rare earth modification additive is a mixture of lanthanum cerium oxide, yttrium-rich rare earth oxide, α-activated alumina and solid waste silicon micropowder, and the mass proportions of lanthanum cerium oxide, yttrium-rich rare earth oxide, α-activated alumina and solid waste silicon micropowder are 76.5%, 13.5%, 7.2% and 2.8% respectively.
[0031] Specifically, the preparation process of the rare earth modified additive includes:
[0032] The lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a blast drying oven, dried at 110° C. for 24 hours, and then the dried lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a muffle furnace, heated from room temperature to 1000° C. for 180 minutes, and then kept at 1000° C. for 6 hours for calcination, and the calcined powders are ball-milled appropriately, and then sieved through a 200-mesh sieve, with a sieve residue of less than 3%, to obtain lanthanum cerium oxide and yttrium-rich rare earth oxide, which are packaged for later use;
[0033] The obtained lanthanum cerium oxide and yttrium-rich rare earth oxide are mixed with α-activated alumina and solid waste silicon powder, wet-milled for 12 hours, and then the slurry is dried at 110°C to 150°C. After drying, the powder is ground and passed through a 200-mesh sieve with a sieve residue of less than 3% to obtain a rare earth modification additive, which is packaged for later use.
[0034] Specifically, the clay is a mixture of Guangxi white mud and Shuozhou soil; the aluminate cement is a mixture of CA70 and CA80; the water reducer is FDN high-efficiency water reducer; and the dispersant is sodium hexametaphosphate.
[0035] The preparation method of the rare earth additive modified thermal storage body castable comprises the following steps:
[0036] S1. Ingredients: According to the above weight ratio, high-alumina bauxite, plate-shaped corundum, solid waste silicon powder, clay, rare earth modification additive, aluminate cement, explosion-proof fiber, water reducer and dispersant are weighed respectively;
[0037] S2. Mixing raw materials: Stirring and mixing the ingredients prepared in step S1 to obtain a mixed material, and then adding water to the mixed material and stirring and mixing to obtain a viscous rare earth additive modified thermal storage body casting material.
[0038] Specifically, the mixing process of the mixed material in step S2 is as follows: first, put the aggregate consisting of 5-8 mm high alumina bauxite, 3-5 mm high alumina bauxite, 1-3 mm high alumina bauxite and 0-1 mm plate-shaped corundum into a mixer and stir for 2 minutes, then add 200 mesh plate-shaped corundum, 325 mesh plate-shaped corundum, solid waste silicon micropowder, clay and aluminate cement and continue stirring for 3 minutes, finally add rare earth modification additives, explosion-proof fibers, water reducers and dispersants and stir for 2 minutes until the material powder is evenly stirred.
[0039] Furthermore, in step S2, when adding water to the mixed material, water is added while stirring, and the state of the material is observed. The total amount of water added is 4-6% of the final castable, and the stirring time for adding water is 3 minutes, until the mixture is stirred and mixed and has viscosity.
[0040] Furthermore, the above preparation method also includes:
[0041] S3, molding: inject the casting material obtained in step S2 into the mold, and shake it to remove bubbles and compact the material.
[0042] S4, curing and firing: the material obtained in step 3 is naturally cured for 12 to 24 hours and then demolded, and then the sample strip is dried and calcined at high temperature to obtain a rare earth additive modified thermal storage body casting material sample block.
[0043] Step S4 is specifically as follows: placing the material obtained in step 3 into a 110°C forced air drying oven and drying it for 24 hours. After drying, take out the sample and place it in a muffle furnace. From room temperature to 1000°C, heat up for 170 minutes, and keep at 1000°C for 30 minutes; from 1000°C to 1450°C, heat up for 150 minutes, and keep at 1450°C for 3 hours. As the furnace temperature naturally cools to room temperature, take out the sample to obtain the rare earth additive modified thermal storage body castable sample.
[0044] The following is explained in conjunction with specific embodiments:
[0045] Table 1 Main ingredients of raw materials used in Examples and Comparative Examples
[0046]
[0047]
[0048] Table 2 Equipment information table used in the examples and comparative examples
[0049]
[0050]
[0051] Example 1
[0052] S1. Preparation process of rare earth modified additives:
[0053] The lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a blast drying oven, dried at 110° C. for 24 hours, and then the dried lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a muffle furnace, heated from room temperature to 1000° C. for 180 minutes, and then kept at 1000° C. for 6 hours for calcination, and the calcined powders are ball-milled appropriately, and then sieved through a 200-mesh sieve, with a sieve residue of less than 3%, to obtain lanthanum cerium oxide and yttrium-rich rare earth oxide, which are packaged for later use;
[0054] The obtained lanthanum cerium oxide, yttrium-rich rare earth oxide, α-activated alumina and solid waste silicon powder are mixed in a mass ratio of 76.5%, 13.5%, 7.2% and 2.8%, wet ball milled for 12 hours, and then the slurry is dried at 110°C. After drying, the powder is ground and passed through a 200-mesh sieve with a sieve residue of less than 3% to obtain a rare earth modification additive, which is packaged for later use.
[0055] S2. Ingredients: The ingredients are prepared according to the following raw materials in parts by weight: 20 parts of 5-8mm high alumina bauxite, 15 parts of 3-5mm high alumina bauxite, 15 parts of 1-3mm high alumina bauxite, 17 parts of 0-1mm plate-shaped corundum, 8 parts of 200 mesh plate-shaped corundum, 13 parts of 325 mesh plate-shaped corundum, 3 parts of solid waste silicon powder, 3 parts of clay (2 parts of Guangxi white mud, 1 part of Shuozhou soil), 6 parts of aluminate cement (2 parts of CA70, 4 parts of CA80), 0.1 parts of explosion-proof fiber, 0.15 parts of FDN high-efficiency water reducer, 0.05 parts of sodium hexametaphosphate dispersant, and 1 part of rare earth modification additive.
[0056] S3. Raw material mixing: first put the aggregate consisting of 5-8mm high alumina bauxite, 3-5mm high alumina bauxite, 1-3mm high alumina bauxite and 0-1mm plate-shaped corundum into a mixer and stir for 2 minutes, then add the fine powder consisting of 200 mesh plate-shaped corundum, 325 mesh plate-shaped corundum, solid waste silicon powder, clay and aluminate cement and continue stirring for 3 minutes, finally add rare earth modified additives, explosion-proof fiber, water reducer and dispersant and stir for 2 minutes until the material powder is evenly stirred. After the material powder is evenly stirred, start the mixer again, add water while stirring, observe the material state, the amount of water added is 5% of the final castable, the stirring time is 3 minutes, until the stirring is evenly mixed and has viscosity, and the rare earth additive modified thermal storage body castable is obtained.
[0057] S4, molding: inject the casting material obtained in step 3 into a 3-bridge mold with a size of 160mm×40mm×40mm, and vibrate it on a vibration table at 50HZ for 2min to remove bubbles and vibrate the material.
[0058] S5. Curing and firing: The molded material is naturally cured for 24 hours and then demolded. The specimens are then placed in a 110°C forced air drying oven and dried for 24 hours. After drying, a portion of the specimens are placed in a muffle furnace. From room temperature to 1000°C, the temperature is increased for 170 minutes, and then kept at 1000°C for 30 minutes; from 1000°C to 1450°C, the temperature is increased for 150 minutes, and then kept at 1450°C for 3 hours. As the furnace temperature naturally cools to room temperature, the specimens are taken out to obtain the rare earth additive modified thermal storage body castable specimens.
[0059] Example 2
[0060] Different from Example 1, S2, ingredients: the ingredients are prepared according to the following raw materials in parts by weight: 20 parts of 5-8mm high alumina bauxite, 15 parts of 3-5mm high alumina bauxite, 15 parts of 1-3mm high alumina bauxite, 17 parts of 0-1mm plate-shaped corundum, 8 parts of 200 mesh plate-shaped corundum, 13 parts of 325 mesh plate-shaped corundum, 3 parts of solid waste silicon powder, 3 parts of clay (2 parts of Guangxi white mud, 1 part of Shuozhou soil), 6 parts of aluminate cement (2 parts of CA70, 4 parts of CA80), 0.1 parts of explosion-proof fiber, 0.15 parts of FDN high-efficiency water reducer, 0.05 parts of sodium hexametaphosphate dispersant, and 3 parts of rare earth modification additives.
[0061] Example 3
[0062] Different from Example 1, S2, ingredients: the ingredients are prepared according to the following raw materials in parts by weight: 20 parts of 5-8mm high alumina bauxite, 15 parts of 3-5mm high alumina bauxite, 15 parts of 1-3mm high alumina bauxite, 17 parts of 0-1mm plate-shaped corundum, 8 parts of 200 mesh plate-shaped corundum, 13 parts of 325 mesh plate-shaped corundum, 3 parts of solid waste silicon powder, 3 parts of clay (2 parts of Guangxi white mud, 1 part of Shuozhou soil), 6 parts of aluminate cement (2 parts of CA70, 4 parts of CA80), 0.1 parts of explosion-proof fiber, 0.15 parts of FDN high-efficiency water reducer, 0.05 parts of sodium hexametaphosphate dispersant, and 5 parts of rare earth modification additives.
[0063] Comparative Example 1
[0064] S1. Ingredients: The ingredients are prepared according to the following raw materials in parts by weight: 20 parts of 5-8mm high alumina bauxite, 15 parts of 3-5mm high alumina bauxite, 15 parts of 1-3mm high alumina bauxite, 17 parts of 0-1mm plate-shaped corundum, 8 parts of 200 mesh plate-shaped corundum, 13 parts of 325 mesh plate-shaped corundum, 3 parts of solid waste silicon powder, 3 parts of clay (2 parts of Guangxi white mud, 1 part of Shuozhou soil), 6 parts of aluminate cement (2 parts of CA70, 4 parts of CA80), 0.1 parts of explosion-proof fiber, 0.15 parts of FDN high-efficiency water reducer, and 0.05 parts of sodium hexametaphosphate dispersant.
[0065] S2. Raw material mixing: first put the aggregate consisting of 5-8mm high alumina bauxite, 3-5mm high alumina bauxite, 1-3mm high alumina bauxite and 0-1mm plate-shaped corundum into a mixer and stir for 2 minutes, then add the fine powder consisting of 200 mesh plate-shaped corundum, 325 mesh plate-shaped corundum, solid waste silicon powder, clay and aluminate cement and continue stirring for 3 minutes, finally add explosion-proof fiber, water reducer and dispersant and stir for 2 minutes until the material powder is evenly stirred. After the material powder is evenly stirred, start the mixer, add water while stirring, observe the material state, the amount of water added is 5% of the final castable, the stirring time is 3 minutes, until the stirring is evenly mixed and has viscosity, and the thermal storage body castable is obtained.
[0066] S3, molding: inject the casting material obtained in step 2 into a 3-bridge mold with a size of 160mm×40mm×40mm, and vibrate it on a vibration table at 50HZ for 2min to remove bubbles and vibrate the material.
[0067] S4. Curing and firing: The molded material is naturally cured for 24 hours and then demolded. The specimens are then placed in a 110°C forced air drying oven and dried for 24 hours. After drying, a portion of the specimens are placed in a muffle furnace. From room temperature to 1000°C, the temperature is increased for 170 minutes, and then kept at 1000°C for 30 minutes; from 1000°C to 1450°C, the temperature is increased for 150 minutes, and then kept at 1450°C for 3 hours. As the furnace temperature naturally cools to room temperature, the castable specimens are taken out.
[0068] Comparative Example 2
[0069] S1. Ingredients: The ingredients are prepared according to the following raw materials in parts by weight: 20 parts of 5-8mm high alumina bauxite, 15 parts of 3-5mm high alumina bauxite, 15 parts of 1-3mm high alumina bauxite, 17 parts of 0-1mm plate-shaped corundum, 8 parts of 200 mesh plate-shaped corundum, 13 parts of 325 mesh plate-shaped corundum, 3 parts of solid waste silicon powder, 3 parts of clay (2 parts of Guangxi white mud, 1 part of Shuozhou soil), 6 parts of aluminate cement (2 parts of CA70, 4 parts of CA80), 0.1 parts of explosion-proof fiber, 0.15 parts of FDN high-efficiency water reducer, 0.05 parts of sodium hexametaphosphate dispersant, and 5 parts of lanthanum cerium oxide.
[0070] S2. Mixing raw materials: first put the aggregate consisting of 5-8mm high alumina bauxite, 3-5mm high alumina bauxite, 1-3mm high alumina bauxite and 0-1mm plate-shaped corundum into a mixer and stir for 2 minutes, then add the fine powder consisting of 200 mesh plate-shaped corundum, 325 mesh plate-shaped corundum, solid waste silicon powder, clay and aluminate cement and continue stirring for 3 minutes, finally add lanthanum oxide cerium, explosion-proof fiber, water reducer and dispersant and stir for 2 minutes until the material powder is evenly mixed. After the material powder is evenly mixed, start the mixer again, add water while stirring, observe the material state, the amount of water added is 5% of the final castable, the stirring time is 3 minutes, until the stirring is evenly mixed and has viscosity, and the thermal storage body castable is obtained.
[0071] S3, molding: inject the casting material obtained in step 2 into a 3-bridge mold with a size of 160mm×40mm×40mm, and vibrate it on a vibration table at 50HZ for 2min to remove bubbles and vibrate the material.
[0072] S4. Curing and firing: The molded material is naturally cured for 24 hours and then demolded. The specimens are then placed in a 110°C forced air drying oven and dried for 24 hours. After drying, a portion of the specimens are placed in a muffle furnace. From room temperature to 1000°C, the temperature is increased for 170 minutes, and then kept at 1000°C for 30 minutes; from 1000°C to 1450°C, the temperature is increased for 150 minutes, and then kept at 1450°C for 3 hours. As the furnace temperature naturally cools to room temperature, the castable specimens are taken out.
[0073] Comparative Example 3
[0074] S1. Ingredients: The ingredients are prepared according to the following raw materials in parts by weight: 20 parts of 5-8mm high alumina bauxite, 15 parts of 3-5mm high alumina bauxite, 15 parts of 1-3mm high alumina bauxite, 17 parts of 0-1mm plate-shaped corundum, 8 parts of 200 mesh plate-shaped corundum, 13 parts of 325 mesh plate-shaped corundum, 3 parts of solid waste silicon powder, 3 parts of clay (2 parts of Guangxi white mud, 1 part of Shuozhou soil), 6 parts of aluminate cement (2 parts of CA70, 4 parts of CA80), 0.1 parts of explosion-proof fiber, 0.15 parts of FDN high-efficiency water reducer, 0.05 parts of sodium hexametaphosphate dispersant, and 5 parts of yttrium-rich rare earth oxide.
[0075] S2. Raw material mixing: first put the aggregate consisting of 5-8mm high alumina bauxite, 3-5mm high alumina bauxite, 1-3mm high alumina bauxite and 0-1mm plate-shaped corundum into a mixer and stir for 2 minutes, then add the fine powder consisting of 200 mesh plate-shaped corundum, 325 mesh plate-shaped corundum, solid waste silicon powder, clay and aluminate cement and continue stirring for 3 minutes, finally add yttrium-rich rare earth oxide, explosion-proof fiber, water reducer and dispersant and stir for 2 minutes until the material powder is evenly mixed. After the material powder is evenly mixed, start the mixer again, add water while stirring, observe the material state, the amount of water added is 5% of the final castable, the stirring time is 3 minutes, until the stirring is evenly mixed and has viscosity, and the thermal storage body castable is obtained.
[0076] S3, molding: inject the casting material obtained in step 2 into a 3-bridge mold with a size of 160mm×40mm×40mm, and vibrate it on a vibration table at 50HZ for 2min to remove bubbles and vibrate the material.
[0077] S4. Curing and firing: The molded material is naturally cured for 24 hours and then demolded. The specimens are then placed in a 110°C forced air drying oven and dried for 24 hours. After drying, a portion of the specimens are placed in a muffle furnace. From room temperature to 1000°C, the temperature is increased for 170 minutes, and then kept at 1000°C for 30 minutes; from 1000°C to 1450°C, the temperature is increased for 150 minutes, and then kept at 1450°C for 3 hours. As the furnace temperature naturally cools to room temperature, the castable specimens are taken out.
[0078] Performance test results:
[0079]
[0080] According to the test results obtained in the table, it can be seen from Examples 1, 2, 3 and Comparative Examples 1, 2, 3 that adding different proportions of rare earth modified additives can effectively improve the bulk density of the castable, and improve the flexural strength, compressive strength and heat storage capacity. This shows that the rare earth additives, under high temperature conditions, use their unique physical and chemical properties to react with SiO2 in the refractory castable to more easily generate new component phases, such as (LaCe)2·2SiO2, La2O3·SiO2, Y2O3·SiO2 or Ho2O3·SiO2, etc., to promote the growth and development of crystalline phases such as mullite (3Al2O3·2SiO2), improve the crystallinity of phase change products, improve the microstructure of the castable, and thus improve the density and flexural and compressive strength of the refractory castable, reduce the porosity and thermal conductivity, and thus improve the heat storage rate of the material. However, while increasing the density, the linear change rate of the castable increases. When only a single rare earth additive of lanthanum cerium oxide or yttrium-rich rare earth oxide is added, although the bulk density, flexural strength, compressive strength and heat storage capacity of the castable are also improved, the increase is lower than that of the castable with the same amount of rare earth modified additives added, indicating that the effect of adding lanthanum cerium oxide and yttrium-rich rare earth oxide at the same time is more obvious than that of a single rare earth additive.
[0081] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A rare earth additive modified thermal storage body castable, characterized in that: The invention comprises the following raw materials in parts by weight: 10 to 30 parts of 5 to 8 mm high alumina bauxite, 10 to 25 parts of 3 to 5 mm high alumina bauxite, 15 to 35 parts of 1 to 3 mm high alumina bauxite, 10 to 30 parts of 0 to 1 mm plate-shaped corundum, 7 to 20 parts of 200 mesh plate-shaped corundum, 10 to 20 parts of 325 mesh plate-shaped corundum, 2 to 5 parts of solid waste silicon micropowder, 2 to 5 parts of clay, 1 to 5 parts of rare earth modification additive, 5 to 10 parts of aluminate cement, 0.1 to 0.3 parts of explosion-proof fiber, 0.05 to 0.2 parts of water reducer and 0.05 to 0.2 parts of dispersant.
2. The rare earth additive modified thermal storage body castable according to claim 1, characterized in that: The rare earth modification auxiliary agent is prepared by mixing lanthanum cerium oxide, yttrium-rich rare earth oxide, alpha-active alumina and solid waste silicon micropowder.
3. The rare earth additive modified thermal storage body castable according to claim 2, characterized in that: The mass proportions of lanthanum cerium oxide, yttrium-rich rare earth oxide, α-activated alumina and solid waste silicon micropowder in the rare earth modification additive are 76.5%, 13.5%, 7.2% and 2.8% respectively.
4. The rare earth additive modified thermal storage body castable according to claim 2, characterized in that: The preparation process of the rare earth modification additive comprises: The lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a blast drying oven, dried at 110°C for 24 hours, and then the dried lanthanum cerium carbonate rare earth and the yttrium-rich carbonate rare earth are placed in a muffle furnace, heated from room temperature to 1000°C for 180 minutes, and then kept at 1000°C for 6 hours for calcination, and the calcined powders are respectively ball-milled appropriately, and then sieved through a 200-mesh sieve, with the sieve residue less than 3%, to obtain lanthanum cerium oxide and yttrium-rich rare earth oxide, which are packaged for later use; The obtained lanthanum cerium oxide and yttrium-rich rare earth oxide are mixed with α-activated alumina and solid waste silicon powder, wet-milled for 12 hours, and then the slurry is dried at 110°C to 150°C. After drying, the powder is ground and passed through a 200-mesh sieve with a sieve residue of less than 3% to obtain a rare earth modification additive, which is packaged for later use.
5. The rare earth additive modified thermal storage body castable according to claim 1, characterized in that: The clay is a mixture of Guangxi white mud and Shuozhou soil; the aluminate cement is a mixture of CA70 and CA80; the water reducer is FDN high-efficiency water reducer; and the dispersant is sodium hexametaphosphate.
6. A method for preparing the rare earth additive modified thermal storage body castable according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Ingredients: Weigh high alumina, plate-shaped corundum, solid waste silicon powder, clay, rare earth modification additive, aluminate cement, explosion-proof fiber, water reducer and dispersant according to the weight ratio described in any one of claims 1 to 5; S2. Mixing raw materials: Stirring and mixing the ingredients prepared in step S1 to obtain a mixed material, and then adding water to the mixed material and stirring and mixing to obtain a viscous rare earth additive modified thermal storage body casting material.
7. The method for preparing the rare earth additive modified thermal storage body castable according to claim 6, characterized in that: The mixing process of the mixed material in step S2 is specifically as follows: first, put the aggregate consisting of 5-8 mm high alumina bauxite, 3-5 mm high alumina bauxite, 1-3 mm high alumina bauxite and 0-1 mm plate-shaped corundum into a mixer and stir for 2 minutes, then add 200 mesh plate-shaped corundum, 325 mesh plate-shaped corundum, solid waste silicon micropowder, clay and aluminate cement and continue stirring for 3 minutes, finally add rare earth modification additives, explosion-proof fibers, water reducers and dispersants and stir for 2 minutes until the material powder is evenly stirred.
8. The method for preparing the rare earth additive modified thermal storage body castable according to claim 6, characterized in that: In step S2, when adding water to the mixed material, add water while stirring, observe the state of the material, and the total amount of water added is 4-6% of the final castable material. The stirring time for adding water is 3 minutes, until it is stirred and mixed and has viscosity.
9. The method for preparing the rare earth additive modified thermal storage body castable according to claim 6, characterized in that: The preparation method further comprises: S3, molding: injecting the casting material obtained in step S2 into the mold, shaking to remove bubbles and compacting the material; S4, curing and firing: the material obtained in step 3 is naturally cured for 12 to 24 hours and then demolded, and then the sample strip is dried and calcined at high temperature to obtain a rare earth additive modified thermal storage body casting material sample block.
10. The method for preparing the rare earth additive modified thermal storage body castable according to claim 9, characterized in that: Step S4 is specifically as follows: placing the material obtained in step 3 into a 110°C forced air drying oven and drying it for 24 hours. After drying, take out the sample and place it in a muffle furnace. From room temperature to 1000°C, heat up for 170 minutes, and keep at 1000°C for 30 minutes; from 1000°C to 1450°C, heat up for 150 minutes, and keep at 1450°C for 3 hours. As the furnace temperature naturally cools to room temperature, take out the sample to obtain the rare earth additive modified thermal storage body castable sample.