A method for increasing the fire resistance of foamed ceramics

Abstract

This invention provides a method for improving the refractory limit of foamed ceramics, comprising the following steps: S1, raw material treatment: preparing ceramic raw materials and a foaming agent, mixing the ceramic raw materials evenly, and then ball milling for 20-25 hours to obtain pretreated raw materials; S2, granulation: mixing the pretreated raw materials and the foaming agent and then granulating to obtain granulated particles with a preset particle size distribution; S3, firing: placing the granulated particles into a kiln for firing, causing the raw materials to foam and sinter at high temperature to obtain foamed ceramics with a porous structure; S4, dry cutting: using a dry cutting process to cut the foamed ceramics with a porous structure, without using water as a coolant or lubricant; S5, packaging: packaging the dry-cut foamed ceramics. This method for improving the refractory limit of foamed ceramics can prevent moisture from penetrating into the porous structure and significantly improve the overall refractory limit and high-temperature service performance of the foamed ceramics.

Description

Technical Field

[0001] This invention relates to the field of foamed ceramics technology, and more specifically, to a method for improving the refractory limit of foamed ceramics. Background Technology

[0002] Ceramic materials, with their excellent high-temperature resistance, stable chemical properties, and good mechanical strength, have been widely used in various fields such as building envelope, industrial kilns, and high-temperature pipeline insulation. Foamed ceramics, as an important branch of ceramic materials, have further endowed the material with excellent properties such as lightweight, thermal insulation, and sound insulation by introducing a controllable porous structure, making them a new type of functional material that has attracted much attention in recent years.

[0003] However, compared to dense traditional ceramic materials, the porous structure of foamed ceramics results in a significant shortcoming in its fire resistance, severely limiting its application in critical scenarios with stringent fire resistance requirements. Existing research data confirms the severity of this problem. For example, the study by Cai Yongrong et al., "Fire Resistance Limit Analysis of Foamed Ceramic Boards of Different Thicknesses," shows that the fire resistance limit of foamed ceramic boards is generally less than 30 minutes, with 10cm thick foamed ceramic boards only exceeding 20 minutes. Although the fire resistance performance of foamed ceramics is affected by quality factors such as board manufacturing processes and raw material ratios, this research result also clearly reflects the inherent defect of foamed ceramics being highly susceptible to fire resistance failure.

[0004] In existing technologies, after the foamed ceramic body is formed, it needs to undergo surface peeling and edge trimming through machining to obtain standard-sized products that meet application requirements. To ensure smooth processing, avoid damage to the cutting tools caused by the high temperatures generated during processing, and reduce breakage of the ceramic body due to processing stress, water is commonly used as a coolant and lubricant in the industry. While this water-based processing method can guarantee processing efficiency and accuracy to a certain extent, it can lead to a fatal problem: foamed ceramics have a large number of interconnected or semi-interconnected micropores with extremely thin walls, making them prone to microcracks during processing. The water used in processing can quickly penetrate into the internal structure of the foamed ceramic through these micropores and microcracks and remain there. When the foamed ceramic is used in high-temperature environments such as fires, the residual water will rapidly absorb heat and vaporize, producing a large amount of water vapor. Due to the certain degree of sealing of the microporous structure of foamed ceramics, the vaporized water vapor cannot be discharged in time, creating a continuously increasing vapor pressure inside the material. The steam pressure continuously impacts the already thin micropore walls, causing the micropores to break one by one, which in turn damages the overall structure of the foamed ceramic. The material thickness gradually decreases, the strength drops rapidly, and eventually it can no longer withstand the attack of flames and high temperatures, resulting in a significant reduction in the fire resistance limit.

[0005] If the fire resistance limit of foamed ceramics cannot meet the relevant industry standards, its application scope will be severely limited, failing to meet the needs of high-rise buildings, large industrial plants, and underground projects that require high fire resistance. This significantly hinders the industrialization and application value enhancement of foamed ceramics as a high-quality lightweight insulation material. Therefore, addressing the core issue of low fire resistance limits in existing foamed ceramics due to the introduction and residue of water during processing, developing a technical solution to reduce the introduction and impact of water during preparation and processing, thereby improving the fire resistance of foamed ceramics, has become an urgent technical challenge to be solved in this field. Summary of the Invention

[0006] This invention aims to address the technical problem of low refractoriness of foamed ceramics mentioned in the background section, and provides a method to improve the refractoriness of foamed ceramics. By optimizing the processing technology to reduce the negative impact of water, the refractoriness of foamed ceramics is improved, enabling them to meet the needs of more demanding applications.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for improving the refractoriness of foamed ceramics, comprising the following steps: S1. Raw material processing: Prepare ceramic raw materials and foaming agent, mix the ceramic raw materials evenly, and then pulverize and ball mill for 20-25 hours to obtain pretreated raw materials; S2. Granulation: The pretreated raw materials and foaming agent are mixed and then granulated to obtain granulated particles with a preset particle size distribution. S3. Firing: The granulated particles are placed in a kiln for firing, and the raw materials are foamed and sintered at high temperature to obtain foamed ceramics with a porous structure. S4. Dry cutting: The foamed ceramic with a porous structure is cut using a dry cutting process, wherein water is not used as a coolant or lubricant. S5. Packaging: The dried foamed ceramic is packaged.

[0008] Further, in step S1, the ceramic raw materials include, by mass, 30-50 parts of tantalum-niobium tailings, 30-50 parts of lithium tailings, 5-10 parts of ceramic waste, 1-5 parts of magnesia, 2.5 parts of kaolin, 5-10 parts of potassium feldspar powder, 0.1-2 parts of silicon carbide, and 0-1 parts of tripolyphosphate.

[0009] Further, in step S2, the foaming agent comprises, by weight, 0.25-0.5 parts silicon carbide and / or 0.05-0.15 parts manganese dioxide.

[0010] Furthermore, the granulation process in step S2 specifically includes the following steps: S21: The foaming agent is ball-milled at a speed of 600-800 rpm for 20-25 hours; S22: Mix polyvinyl alcohol aqueous solution, paraffin wax and bentonite in a mass ratio of (2-5):1:1 to obtain granulation solution; S23: The granulation liquid and the ball-milled foaming agent are mixed at a mass ratio of 1:(0.3-0.5), and the pretreated raw materials are added. After atomization and drying, the granulated particles are obtained.

[0011] Furthermore, the firing process in step S3 specifically includes the following steps: S31: The granulated granules are spread and shaped by a material spreading machine. The material spreading is done by spreading the material onto the forming mold without applying pressure. S32: Place the formed green body into the kiln and heat it to 400-410℃ at a heating rate of 9-12℃ / min, and hold it for 30-35 minutes to dehydrate it; S33: Heat to 850-860℃ at a heating rate of 8-10℃ / min, and hold for 60-65 minutes for pre-firing; S34: Heat to 1050-1120℃ at a heating rate of 3.5-4.5℃ / min, and hold for 40-60 minutes for foaming; S35: Raise the temperature to 1180-1250℃ at a heating rate of 4-5℃ / min and hold for 50-70min to crystallize; S36: Cool the temperature to 400-410℃ at a rate of 6-10℃ / min, and hold for 3-4 hours to obtain the foamed ceramic.

[0012] Furthermore, in step S4, the dry cutting process uses a diamond saw blade, a metal saw blade, a laser, a highly volatile lubricant, or an electrical discharge wire for cutting.

[0013] Furthermore, it also includes a sealing step: after the dry cutting is completed in step S4 and before packaging in step S5, the foamed ceramic is sealed. The specific steps of the sealing process are as follows: ultrasonically clean the dried foamed ceramic for 20-25 minutes, dry it at 120-125℃ for 2-2.5 hours, then immerse it in the sealing agent for 30-35 minutes at an immersion temperature of 50-60℃, and then pre-dry it at 80-85℃ for 1-1.5 hours and heat treat it at 350-360℃ for 2-2.5 hours to complete the sealing process.

[0014] Further, by weight percentage, the sealing agent comprises: 40-45% silica sol, 30-35% aluminum sol, 0.5-1% polyethylene glycol, and the balance being deionized water.

[0015] The beneficial effects of this invention are as follows: In the production process of foamed ceramics, especially in the processing stage, to solve the problem of water introduction and influence during the preparation of foamed ceramics, this invention adopts an anhydrous dry cutting process to replace the existing water-cooled cutting method, reducing water introduction. The most core and direct benefit is to prevent moisture from penetrating into the porous structure. This fundamentally avoids catastrophic cracking and structural failure caused by the rapid vaporization and expansion of internal moisture when the material is used as a refractory material in a high-temperature environment. This is a prerequisite for ensuring its high refractory limit. At the same time, the dry cutting process reduces water introduction, maintains the strength of the matrix, and ensures that the matrix is ​​fully dry before sealing, allowing the sealing agent to effectively penetrate and form a film, creating favorable conditions for subsequent sealing processes, and significantly improving the overall refractory limit and high-temperature service performance of the foamed ceramics. This invention seals the pores of foamed ceramics with a sealing agent. Foamed ceramics contain a large number of open pores, which can be directly penetrated by flames and hot air at high temperatures, accelerating heat conduction and material erosion. The sealing agent can form a dense film on the pore walls, effectively sealing the pores, blocking the intrusion of high-temperature gases and molten materials, and slowing down the transfer of heat to the interior of the material. After sealing the pores, the internal still air is effectively locked in, which greatly reduces the overall effective thermal conductivity of the material, improves its high-temperature resistance, and thus improves the fire resistance limit of the foamed ceramics. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only drawings of some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of the present invention.

[0017] Figure 1 This is a schematic diagram of the method steps of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0019] A method to improve the refractory limit of foamed ceramics, such as Figure 1 As shown, it includes the following steps: S1. Raw material processing: Prepare ceramic raw materials and foaming agent. After the ceramic raw materials are mixed evenly, they are pulverized and ball-milled for 20 hours to obtain pretreated raw materials. The ceramic raw materials, by weight, include: 30 parts tantalum-niobium tailings, 30 parts lithium tailings, 5 parts ceramic waste, 1 part magnesia, 2.5 parts kaolin, 5 parts potassium feldspar powder, 0.1 parts silicon carbide, and 0.1 parts tripolyphosphate.

[0020] S2. Granulation: The pretreated raw materials and foaming agent are mixed and granulated to form particles with a certain particle size distribution for subsequent firing processes. The foaming agent, by weight, comprises: 0.25 parts silicon carbide and 0.05 parts manganese dioxide; The foaming agent was ball-milled at 600 rpm for 20 hours. Then, polyvinyl alcohol aqueous solution, paraffin and bentonite were mixed in a mass ratio of 2:1:1 to obtain granulation solution. The granulation solution and the ball-milled foaming agent were mixed in a mass ratio of 1:0.3, and pretreated raw materials were added. The mixture was then atomized and dried to obtain granulated particles.

[0021] S3, Firing: The granulated particles are placed in a kiln for firing, and the raw materials are foamed and sintered at high temperature to form foamed ceramics with a porous structure. After granulation, the granules are shaped into blanks, which are then placed in a kiln. The kiln is heated to 400°C at a rate of 9°C / min and held for 30 minutes to dehydrate the blanks. Then, increase the temperature to 850℃ at a rate of 8℃ / min and hold for 60 minutes for pre-firing; The temperature was then increased to 1050℃ at a rate of 3.5℃ / min and held for 40 minutes for foaming. Then, the temperature was increased to 1180℃ at a rate of 4℃ / min and held for 50min for crystallization. Finally, the slurry temperature was reduced to 400℃ at a rate of 6℃ / min, and held at that temperature for 3 hours to slow cooling and prevent cracking, thus obtaining foamed ceramics with a porous structure.

[0022] S4. Dry cutting: Dry cutting is used to process the fired foamed ceramics, avoiding the use of water as a coolant and lubricant, thereby reducing the introduction of water. The dry cutting process can use diamond saw blades, metal saw blades, lasers, highly volatile lubricants, or electrical discharge wires, etc., to cut without leaving water, and to cut and process the foamed ceramics under waterless conditions. The specific steps for sealing foamed ceramics are as follows: ultrasonically clean the dried foamed ceramics for 20 minutes, dry them at 120℃ for 2 hours, then immerse them in a sealing agent for 30 minutes at a temperature of 50℃, and then pre-dry them at 80℃ for 1 hour and heat-treat them at 350℃ for 2 hours to complete the sealing process. The sealing agent, by weight percentage, comprises: 40% silica sol, 30% aluminum sol, 0.5% polyethylene glycol, and deionized water to make up the balance.

[0023] S5. Packaging: Pack the dry-cut and sealed foamed ceramics for storage and transportation. Example

[0024] A method to improve the refractory limit of foamed ceramics, such as Figure 1 As shown, it includes the following steps: S1. Raw material processing: Prepare ceramic raw materials and foaming agent, mix the ceramic raw materials evenly and then pulverize and ball mill for 22.5 hours to obtain pretreated raw materials; The ceramic raw materials, by weight, include: 40 parts tantalum-niobium tailings, 40 parts lithium tailings, 7.5 parts ceramic waste, 2.5 parts magnesia, 2.5 parts kaolin, 7.5 parts potassium feldspar powder, 1 part silicon carbide, and 0.5 parts tripolyphosphate.

[0025] S2. Granulation: The pretreated raw materials and foaming agent are mixed and granulated to form particles with a certain particle size distribution for subsequent firing processes. The foaming agent comprises, by weight, 0.3 parts silicon carbide and 0.1 parts manganese dioxide; The foaming agent was ball-milled at 700 rpm for 22 hours. Then, polyvinyl alcohol aqueous solution, paraffin and bentonite were mixed in a mass ratio of 3:1:1 to obtain granulation solution. The granulation solution and the ball-milled foaming agent were mixed in a mass ratio of 1:0.4, and pretreated raw materials were added. The mixture was then atomized and dried to obtain granulated particles.

[0026] S3, Firing: The granulated particles are placed in a kiln for firing, and the raw materials are foamed and sintered at high temperature to form foamed ceramics with a porous structure. After granulation, the granules are shaped into blanks, which are then placed in a kiln. The kiln is heated to 405°C at a rate of 10°C / min and held for 32 minutes to dehydrate the blanks. Then, raise the temperature to 855℃ at a rate of 9℃ / min and hold for 62 minutes for pre-firing; Then, the temperature was increased to 1100℃ at a rate of 4℃ / min and held for 50 minutes for foaming. Then, the temperature was increased to 1200℃ at a rate of 4℃ / min and held for 60min for crystallization. Finally, the slurry temperature was reduced to 405℃ at a rate of 8℃ / min, and held at that temperature for 3.5h for slow cooling to prevent cracking, thus obtaining foamed ceramics with a porous structure.

[0027] S4. Dry cutting: Dry cutting is used to process the fired foamed ceramics, avoiding the use of water as a coolant and lubricant, thereby reducing the introduction of water. The dry cutting process can use diamond saw blades, metal saw blades, lasers, highly volatile lubricants, or electrical discharge wires, etc., to cut without leaving water, and to cut and process the foamed ceramics under waterless conditions. The specific steps for sealing foamed ceramics are as follows: after dry cutting, the foamed ceramics are ultrasonically cleaned for 22 minutes, dried at 122℃ for 2.2 hours, then immersed in a sealing agent for 32 minutes at an immersion temperature of 55℃, and then pre-dried at 82℃ for 1.2 hours and heat-treated at 355℃ for 2.2 hours to complete the sealing process. The sealing agent, by weight percentage, comprises: 42% silica sol, 32% aluminum sol, 0.8% polyethylene glycol, and deionized water to make up the balance.

[0028] S5. Packaging: Pack the dry-cut and sealed foamed ceramics for storage and transportation. Example

[0029] A method to improve the refractory limit of foamed ceramics, such as Figure 1 As shown, it includes the following steps: S1. Raw material processing: Prepare ceramic raw materials and foaming agent, mix the ceramic raw materials evenly and then pulverize and ball mill for 25 hours to obtain pretreated raw materials; The ceramic raw materials, by weight, include: 50 parts tantalum-niobium tailings, 50 parts lithium tailings, 10 parts ceramic waste, 5 parts magnesia clay, 2.5 parts kaolin, 10 parts potassium feldspar powder, 2 parts silicon carbide, and 1 part tripolyphosphate.

[0030] S2. Granulation: The pretreated raw materials and foaming agent are mixed and granulated to form particles with a certain particle size distribution for subsequent firing processes. The foaming agent comprises, by weight, 0.5 parts silicon carbide and 0.15 parts manganese dioxide; The foaming agent was ball-milled at 800 rpm for 25 hours. Then, polyvinyl alcohol aqueous solution, paraffin and bentonite were mixed in a mass ratio of 5:1:1 to obtain granulation solution. The granulation solution and the ball-milled foaming agent were mixed in a mass ratio of 1:0.5, and pretreated raw materials were added. The mixture was then atomized and dried to obtain granulated particles.

[0031] S3, Firing: The granulated particles are placed in a kiln for firing, and the raw materials are foamed and sintered at high temperature to form foamed ceramics with a porous structure. After granulation, the granulated fabric is shaped and then placed in a kiln. The temperature is first raised to 410℃ at a rate of 12℃ / min and held for 35 minutes for dehydration. Then, increase the temperature to 860℃ at a rate of 10℃ / min and hold for 65 minutes for pre-firing; The temperature was then increased to 1120℃ at a rate of 4.5℃ / min and held for 60 minutes for foaming. Then, the temperature was increased to 1250℃ at a rate of 5℃ / min and held for 70min for crystallization. Finally, the slurry temperature was reduced to 410℃ at a rate of 10℃ / min, and held at that temperature for 4 hours for slow cooling to prevent cracking, thus obtaining foamed ceramic with a porous structure.

[0032] S4. Dry cutting: Dry cutting is used to process the fired foamed ceramics, avoiding the use of water as a coolant and lubricant, thereby reducing the introduction of water. The dry cutting process can use diamond saw blades, metal saw blades, lasers, highly volatile lubricants, or electrical discharge wires, etc., to cut without leaving water, and to cut and process the foamed ceramics under waterless conditions. The specific steps for sealing foamed ceramics are as follows: after dry cutting, the foamed ceramics are ultrasonically cleaned for 25 minutes, dried at 125℃ for 2.5 hours, then immersed in a sealing agent for 35 minutes at an immersion temperature of 60℃, and then pre-dried at 85℃ for 1.5 hours and heat-treated at 360℃ for 2.5 hours to complete the sealing process. The sealing agent, by weight percentage, comprises: 45% silica sol, 35% aluminum sol, 1% polyethylene glycol, and deionized water to make up the balance.

[0033] S5. Packaging: Pack the dry-cut and sealed foamed ceramics for storage and transportation.

[0034] Foamed ceramic bodies of the same batch and specifications, 10cm thick, with a density of 400kg / m³, were selected and divided into two groups: Control group: Traditional wet cutting process, using water cooling for cutting; Experimental group: The dry cutting process of Example 1 of this invention was used for cutting under waterless conditions, using a diamond saw blade for dry cutting, and the processed material was ready for immediate use.

[0035] The control group and the experimental group were tested twice each, for a total of four groups of samples. The fire resistance limit was tested according to the "Classification of Combustion Performance of Building Materials and Products" (GB8624), and the specific duration was recorded (accurate to the minute). The water absorption rate (water absorption of the cut surface and internal micropores) of the two groups of samples after cutting was tested to verify whether dry cutting reduces the introduction of water, as shown in Table 1.

[0036] Samples from the above dry-cutting process experimental group were selected and divided into several subgroups: Subgroup 1: No sealing treatment was performed after dry cutting; Subgroup 2: After dry cutting, a silane-based sealing agent is sprayed on to seal the holes; Subgroup 3: After dry cutting, the holes are sealed by high-temperature sintering, sintering at 800℃ for 1 hour; Subgroup 4: After dry cutting, the pores were sealed using the method described in Example 1.

[0037] Test metrics and data requirements: The fire resistance limit of each subgroup of samples was tested, and the improvement of the fire resistance limit was compared between whether the pores were sealed and different sealing methods. The long-term water absorption rate of each subgroup of samples was tested to verify the effectiveness of the sealing treatment in preventing subsequent water ingress; the surface hardness / abrasion resistance after sealing treatment was tested, as shown in Table 2.

[0038] Foamed ceramics of the same specification with a thickness of 10 cm were prepared using the methods of Examples 1-3 of this invention.

[0039] Test metrics and data requirements: Each batch of samples was tested for its fire resistance limit, and the data fluctuation range was calculated to prove the stability of the process. The improvement of this solution is shown in Table 3, which compares the data with existing technologies.

[0040] Serial Number sample process Moisture content (%) Fire resistance limit (minutes) Fire resistance testing process Control group 1 402kg / m³, 10cm Traditional wet cutting process 1.1 32 Microcracks caused by water immersion are visible on the walls of the micropores on the cut surface, and the pore size distribution is uneven. Control group 2 405kg / m³, 12cm Traditional wet cutting process 1.0 41 Microcracks caused by water immersion are visible on the walls of the micropores on the cut surface, and the pore size distribution is uneven. Experimental group 1 401kg / m³, 10cm Dry cutting process 0 90 The micropore structure on the cut surface is intact, with no cracks in the pore walls, and the pore size uniformity is better than that of the control group. Experimental group 2 403kg / m³, 12cm Dry cutting process 0 102 The micropore structure on the cut surface is intact, with no cracks in the pore walls, and the pore size uniformity is better than that of the control group. Table 2 Subgroup Fire resistance limit (minutes) Long-term water absorption rate (%) 1 128 3.2 2 156 0.8 3 158 0.5 4 162 0.4 Table 3 Serial Number Process (dry cutting + 800℃ sintering and sealing) Fire resistance limit (minutes) Improvement compared to existing technology (wet cutting without sealing) Example 1 10cm thick, 401kg / m³ 159 73% Example 2 10cm thick, 403kg / m³ 161 75% Example 3 10cm thick, 405kg / m³ 162 76% As can be seen from Table 1, the control group had a moisture content of 1.0-1.1% after wet cutting, with obvious microcracks and a fire resistance limit of only 32-41 min; while the experimental group had a moisture content of 0% after dry cutting, with significantly reduced cracks and a fire resistance limit that jumped directly to 90-102 min.

[0041] As can be seen from Table 2, after sealing the hole on the basis of dry cutting, the fire resistance limit continues to increase from about 102 min to 156-162 min. Among them, the fire resistance limit treatment using the dry cutting and sealing agent of the present invention has the longest time, which is 162 min.

[0042] As can be seen from Table 3, the fire resistance limits of Examples 1-3 are 159, 161, and 162 min, respectively, with fluctuations of only ±1 min, corresponding to an improvement of 73-76%, indicating that the process of the present invention is stable and reliable in large-scale production.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for improving the refractoriness of foamed ceramics, characterized in that, Includes the following steps: S1. Raw material processing: Prepare ceramic raw materials and foaming agent, mix the ceramic raw materials evenly, and then pulverize and ball mill for 20-25 hours to obtain pretreated raw materials; S2. Granulation: The pretreated raw materials and foaming agent are mixed and then granulated to obtain granulated particles with a preset particle size distribution. S3. Firing: The granulated particles are placed in a kiln for firing, and the raw materials are foamed and sintered at high temperature to obtain foamed ceramics with a porous structure. S4. Dry cutting: The foamed ceramic with a porous structure is cut using a dry cutting process, wherein water is not used as a coolant or lubricant. S5. Packaging: The dried foamed ceramic is packaged.

2. The method for improving the refractoriness of foamed ceramics according to claim 1, characterized in that: In step S1, the ceramic raw materials include, by mass, 30-50 parts of tantalum-niobium tailings, 30-50 parts of lithium tailings, 5-10 parts of ceramic waste, 1-5 parts of magnesia, 2.5 parts of kaolin, 5-10 parts of potassium feldspar powder, 0.1-2 parts of silicon carbide, and 0-1 parts of tripolyphosphate.

3. The method for improving the refractoriness of foamed ceramics according to claim 1, characterized in that: In step S2, the foaming agent comprises, by weight, 0.25-0.5 parts silicon carbide and / or 0.05-0.15 parts manganese dioxide.

4. The method for improving the refractoriness of foamed ceramics according to claim 1, characterized in that: The granulation process in step S2 specifically includes the following steps: S21: The foaming agent is ball-milled at a speed of 600-800 rpm for 20-25 hours; S22: Mix polyvinyl alcohol aqueous solution, paraffin wax and bentonite in a mass ratio of (2-5):1:1 to obtain granulation solution; S23: The granulation liquid and the ball-milled foaming agent are mixed at a mass ratio of 1:(0.3-0.5), and the pretreated raw materials are added. After atomization and drying, the granulated particles are obtained.

5. The method for improving the refractoriness of foamed ceramics according to claim 1, characterized in that: The firing process in step S3 specifically includes the following steps: S31: The granulated granular fabric is shaped; S32: Place the formed green body into the kiln and heat it to 400-410℃ at a heating rate of 9-12℃ / min, and hold it for 30-35 minutes to dehydrate it; S33: Heat to 850-860℃ at a heating rate of 8-10℃ / min, and hold for 60-65 minutes for pre-firing; S34: Heat to 1050-1120℃ at a heating rate of 3.5-4.5℃ / min, and hold for 40-60 minutes for foaming; S35: Raise the temperature to 1180-1250℃ at a heating rate of 4-5℃ / min and hold for 50-70min to crystallize; S36: Cool the temperature to 400-410℃ at a rate of 6-10℃ / min, and hold for 3-4 hours to obtain the foamed ceramic.

6. The method for improving the refractoriness of foamed ceramics according to claim 1, characterized in that: In step S4, the dry cutting process uses a diamond saw blade, a metal saw blade, a laser, a highly volatile lubricant, or an electrical discharge wire for cutting.

7. The method for improving the refractoriness of foamed ceramics according to claim 1, characterized in that: It also includes a sealing step: after the dry cutting is completed in step S4 and before packaging in step S5, the foamed ceramic is sealed. The specific steps of the sealing process are as follows: ultrasonically clean the dried foamed ceramic for 20-25 minutes, dry it at 120-125℃ for 2-2.5 hours, then immerse it in the sealing agent for 30-35 minutes at an immersion temperature of 50-60℃, and then pre-dry it at 80-85℃ for 1-1.5 hours and heat treat it at 350-360℃ for 2-2.5 hours to complete the sealing process.

8. The method for improving the refractoriness of foamed ceramics according to claim 7, characterized in that: The sealing agent comprises, by weight percentage: 40-45% silica sol, 30-35% aluminum sol, 0.5-1% polyethylene glycol, and the balance being deionized water.

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