A process for the production of foamed ceramics

Abstract

The application provides a foamed ceramic production process and relates to the field of lightweight ceramic material production. The process uses silicon carbide as a foaming agent and comprises the following steps: first, detecting the surface flatness of the foamed ceramic product after being taken out of the kiln to determine the surface topography data of the foamed ceramic product after being taken out of the kiln; then, according to the surface topography data, supplementing the foamed ceramic raw material layer which is prepared by a molding process before being taken into the kiln to burn in the same batch, wherein the raw material used for the supplementing is the same as or basically the same as the surface layer raw material component of the foamed ceramic raw material layer, and the supplementing area is the concave area of the foamed ceramic product after being taken out of the kiln; after the supplementing, the topography of the raw material layer is maintained, and the raw material layer is taken into the kiln to be sintered. The process can improve the flatness of the foamed ceramic after being sintered, reduce the grinding amount of cutting / grinding / polishing, save resources and reduce production cost.

Description

Technical Field

[0001] This invention relates to lightweight ceramic material production technology, specifically to a foamed ceramic production process. Background Technology

[0002] Foamed ceramics are lightweight, porous ceramic materials. Currently, industrial production processes typically involve spreading ceramic powder containing a foaming agent inside a refractory kiln, firing it, and then cooling it after firing. The kiln furniture is then removed, and the raw material is polished and / or cut to obtain the desired shape of the foamed ceramic product. Because the raw materials for foamed ceramics expand during high-temperature sintering, conventional raw material formulations often result in poor surface smoothness. When a smoother surface is desired, the amount of polishing and / or cutting required is substantial, leading to significant waste. Therefore, adjusting the production process to achieve better post-firing smoothness and reduce subsequent polishing and cutting is a key focus within the industry. Summary of the Invention

[0003] This invention provides a foamed ceramic production process that can improve the flatness of fired products and reduce losses during subsequent cutting and polishing.

[0004] A foamed ceramic production process using silicon carbide as a foaming agent includes the following steps: First, the surface flatness of the foamed ceramic products after firing is tested to determine the surface morphology data. Then, based on the surface morphology data, a layer of foamed ceramic raw materials prepared by a molding process before firing in the same batch is added. The raw material used for adding is the same as or substantially the same as the surface raw material composition of the foamed ceramic raw material layer. The added area is the recessed area of ​​the foamed ceramic products after firing. After adding, the morphology of the raw material layer is maintained before firing in the kiln. By testing the flatness of the products after firing, and based on the test data, corresponding additions are made to the raw material layer before firing in the same batch. The added raw material can fill the recessed defects generated in this area during firing, thereby improving the flatness of the foamed ceramic products after firing.

[0005] In existing technologies, foamed ceramics are mainly used as thermal insulation materials, with no specific requirements for their decorative effects. Therefore, polishing and cutting the expanded raw material after firing is the conventional choice under the existing system. Under this process system, there is no need to test the flatness of the fired product, and the flatness of the product is adjusted by adding material. The surface morphology of the fired foamed ceramic product needs to be controllable; otherwise, the effect of adding material is limited. Taking a known foamed ceramic formula system as an example, for a foamed ceramic product with a thickness of 100-160mm after firing, the surface area needs to be within 1m². 2Under the above conditions and with a width > 0.5m, the surface morphology of the product is consistent, that is, the surface morphology is concave in the middle and convex at the edges. This is because when powder is sprinkled in the refractory mold and then fired, the powder near the center of the mold heats up slowly, while the powder near the edge of the mold heats up quickly. This results in the powder layer having a temperature field that is low in the center and high at the edges. When the surface of the foamed ceramic is large, the consistency of the temperature field distribution is enhanced, resulting in a better consistency of the surface morphology of the fired foamed ceramic. By combining this morphology data with the foaming ratio data of the foamed ceramic raw material, the determined feeding process parameters will have better matching.

[0006] Preferably, in the above process, the thickness of the filling material is: the depth of the depression at the filling point / the foaming ratio of the raw material used for filling × 0.8 to 1.2, and the foaming ratio is: the volume of the raw material after molding and firing / the volume of the raw material before molding and firing. More preferably, the foaming ratio of the foamed ceramic should be controlled within a certain range, preferably 1.2 to 2.5. If the foaming ratio is too high, the surface morphology of the foamed ceramic will change significantly after firing, affecting the filling effect; if the foaming ratio is too low, the unique lightweight characteristics of the foamed ceramic cannot be satisfied.

[0007] In production, it is necessary to reduce the frequency of adjusting the pre-feeding parameters. That is, once the process parameters for feeding are determined, the smoothness of the surface of the fired product should be maintained for as long as possible. This requires that the surface morphology parameters of the fired foamed ceramic product remain basically stable without feeding. When the raw material composition of the foamed ceramic powder is a homogeneous component, the main control should be on the method, area, thickness, and foaming ratio of the powder distribution. In industrial production, foamed ceramics are often produced using powder sintering. This involves placing the foamed ceramic raw material powder inside a refractory mold and then firing it in a kiln. Due to the confinement of the refractory mold's frame, the powder layer only expands vertically during firing. The refractory mold has better heat conduction than the foamed ceramic powder, so the periphery near the refractory mold heats up faster and melts before the inner side. During firing, the temperature of the powder near the refractory kiln furniture is higher than that of the powder in the center of the refractory kiln furniture, at least in the early stages of firing. Therefore, the foamed ceramics after firing will exhibit a morphology that is concave from the edges to the center. By inspecting the morphology of the fired foamed ceramic products, the process parameters for replenishing material can be determined based on the depth of the concavity, the trend of change, and the foaming ratio. Replenishing material before firing can improve the flatness of the fired product.

[0008] Furthermore, to enrich the decorative effect of foamed ceramics, various foamed ceramic powders can be used for application. For example, well-known multi-channel mixing application methods can be used, and / or large granular clumps of material can be used in the preset area during application to achieve a richer decorative effect.

[0009] Of course, besides applying foamed ceramic powder into a refractory mold and firing it, another method is to press the foamed ceramic powder into shape and then load it into a kiln for firing using a flat refractory material. However, this increases the difficulty of adding material. Without the restriction of the refractory mold, the method of using powder for adding material requires pre-spraying adhesive on the pressed brick blank or spraying adhesive after adding material for positioning. This is to avoid deviations caused by vibration, blower suction, etc. during the conveying process before firing. The adhesive can be any known substance that can bond the powder to the blank, such as an aqueous solution containing cellulose or other known organic adhesives. In addition to using powder for application, a method similar to glazing can also be used, where the raw materials used for adding material are made into a slurry. Theoretically, any application method that can form a certain thickness of material layer on the surface of the blank is applicable, such as spraying or printing.

[0010] Foamed ceramics have a long firing cycle and are generally not suitable for rapid firing. From an economic perspective, they are often made into large-area, thick slabs to suit industrial production. Currently, industrially produced slabs have a planar size of 3-4m × 1.2-2.7m and a thickness of 3-20cm. These specifications refer to the maximum usable size that can be obtained after polishing and cutting the product after firing. Smaller sizes can be obtained by further cutting and processing. In traditional foamed ceramic raw material formulations, when the specific gravity of the fired product (the ratio of product density to water density) is less than or equal to 1, and the slab strength and other indicators meet the requirements for use as a non-load-bearing material, the foaming ratio is approximately 1.2-2.5. The foaming ratio refers to the ratio of the volume of the fired product to the volume of the raw material before firing. In processes using direct sintering of powder, due to the limitations of the mold rim, the foaming ratio is approximately the ratio of the height of the fired foamed ceramic to the height of the powder before firing.

[0011] Furthermore, in existing technologies, the surface of foamed ceramics is often removed through polishing. However, when sealing pores or achieving specific decorative effects after firing is required, the surface is retained. When foamed ceramics use multi-layer powder fabrication, it includes at least a top layer and a bottom layer. The bottom layer can use conventional foamed ceramic raw materials, while the top layer needs to achieve the desired decorative effect and / or directly withstand environmental erosion. Therefore, the raw material cost is often higher. From a cost perspective, the thinner the top layer, the better. With a thinner top layer, the interface between the top layer and adjacent layers is prone to delamination or large through-holes during firing, affecting the strength and surface smoothness of the foamed ceramic product. By testing the surface morphology of the foamed ceramic after firing, and based on this data, the top layer is replenished before entering the kiln. The replenishing material is the same as or nearly the same as the top layer to ensure the surface smoothness, decorative effect, and other properties of the foamed ceramic product. When using fabrics and base materials with specific properties, the interface layer at the junction of the top and bottom layers can be kept consistent with the interface formed when the fabric is applied. This allows for a thinner fabric layer, ensuring that even with a smaller amount of material and a supplementary material process, the bottom layer will not show through. Even if the surface of the fired foamed ceramic product needs to be polished and leveled, the bottom-showing defect can be controlled to a low level, reducing waste.

[0012] When a richer decorative effect is desired on the surface layer of foamed ceramic, decorative materials can be added to the surface layer raw material in a known manner, such as granular decorative materials, strip-shaped decorative materials, etc. The fabric can be made using known multi-tube magic fabric or other known fabric making methods used for ceramic wall and floor tiles, in order to obtain a rich textured decorative effect.

[0013] Furthermore, the absolute value of the difference between the softening temperature of the base material and the softening temperature of the fabric is ≤10℃. In the foamed ceramic production process using silicon carbide as a foaming agent, under a known raw material formulation system, the suitable firing temperature is approximately 1150℃~1200℃. The softening temperatures of the base material and the fabric are within this range, and the absolute value of the difference between them is ≤10℃. This allows the foaming time of the two layers of raw materials to become similar during firing, thereby improving the controllability and consistency of the post-firing morphology of the double-layer fabric.

[0014] Further preferred, the base material, by mass percentage of oxides, includes: SiO2: 65-69%, Al2O3: 15-17%, Fe2O3: 0-1.5%, TiO2: 0-2%, CaO: 0-2%, MgO: 0-3%, K2O: 2-4%, Na2O: 2-4%, LOI: 2-4%; the fabric, by mass percentage of oxides, includes: SiO2: 63-69%, Al2O3: 15-19%, Fe2O3: 0.5-3%, TiO2: 0-0.5%, CaO: 1-3%, MgO: 2-5%, K2O: 2-5%, Na2O: 2-5%, LOI: 2-6%. Wherein LOI is loss on ignition, which represents the percentage of mass lost by the raw material after ignition at 950℃-1025℃, specifically the percentage of mass lost by the H, C, N, and S elements in the raw material in the form of gaseous oxides. Under this formulation system, the minimum fabric thickness of the outer layer can be as low as 2mm without being see-through, which facilitates subsequent basic processing such as cutting and processing, and also saves on the raw materials of the outer layer, thus saving costs. Attached Figure Description

[0015] Figure 1 This is a graph showing the test data of the high-temperature viscosity (spherical state under a high-temperature microscope) of the bottom raw material in Example 2 of the present invention.

[0016] Figure 2 This is a graph showing the test data of the high-temperature viscosity (spherical state under a high-temperature microscope) of the fabric layer raw material in Example 2 of the present invention.

[0017] Figure 3 This is a side view of the foamed ceramic obtained after feeding in Embodiment 3 of the present invention. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0020] The foaming agent used in the examples is silicon carbide with a purity of 98.5% or higher, which was purchased from Foshan Changyuan New Materials Co., Ltd.

[0021] Those skilled in the art will understand that, referring to the Seger formula based on oxides, it is possible to prepare the required building ceramic products using commonly used mineral raw materials, provided that the firing temperature range is clearly defined. It is important to note the compatibility between the characteristics of different mineral raw materials and the preparation process. Typically, the obtained raw materials need to be ball-milled into a slurry, aged, homogenized, spray-granulated, and then fired at a suitable firing temperature.

[0022] Example 1

[0023] The scheme adopted in this embodiment is that the base powder and the fabric powder are the same powder. The specific chemical composition of the powder is as follows (parts by weight): SiO2: 68.45, Al2O3: 16.82, Fe2O3: 1.11, TiO2: 0.14, CaO: 1.17, MgO: 2.72, K2O: 3.21, Na2O: 3.77, MnO2: 0.1, LOI: 2.61.

[0024] The powder formulation is as follows by weight: foamed ceramic waste (black): 14 parts, Xitai press mud: 33 parts, waste powder: 2 parts, Aika press mud: 15 parts, magnesia clay: 9 parts, foamed ceramic waste (white): 21 parts, Wenting tailings mud: 6 parts, silicon carbide CF-25: 0.35 parts, liquid degumming agent: 1.1 parts, manganese oxide: 0.1 parts. The fineness of the slurry after ball milling is 0.8-1.0% after sieving through a 250-mesh sieve in a standard specific gravity cup.

[0025] It should be noted that the powder formulation components are exemplary, and the names of the raw materials are not their academic names. Under a specific chemical composition system, those skilled in the art can make specific conversions based on the chemical composition of the well-known mineral raw materials used.

[0026] The powder processing parameters are as follows: bulk density 0.87, moisture content 5.2%, and particle size distribution requirements (by weight): 0.81% for particles larger than 20 mesh, 49.31% for particles between 20 and 40 mesh, 85.22% for particles between 20 and 60 mesh, and 1.27% for particles smaller than 100 mesh. The powder is then laid out on the kiln after 24 hours of aging. The kiln furniture dimensions are 3.2m × 1.5m, and the powder thickness is 68mm. The firing cycle is 12 hours and 15 minutes, and the firing temperature is 1163℃.

[0027] The surface morphology of the fired products was tested. The product thickness was 138–148 mm, and the products were concave, with the deepest point of the concavity located in the center. Under this firing regime, the foaming ratio of this raw material was approximately 2.1. When used as a feed material, the feed thickness near the center was 10 mm ÷ 2.1 × 0.8 = 3.8 mm. Typically, the formula for calculating the feed thickness is the concavity depth at the feed point / the foaming ratio of the feed material × 0.8–1.2, where 0.8–1.2 is an adjustment coefficient. By feeding the powder layer before firing in this manner, the thickness of the fired products was 146–150 mm, with a thickness deviation of only 4 mm. This reduces the amount of surface grinding required during leveling.

[0028] Of course, for specific types of boards, such as foamed ceramic boards that need to be processed to a thickness of 140mm, the amount of powder used during the application of the material can be reduced first, adjusting the material thickness to 65mm, and then the material can be replenished. In other words, the reduction in powder thickness during replenishment should be less than or equal to the replenishment thickness value under the minimum adjustment coefficient. Taking this example, the replenishment thickness under the minimum adjustment coefficient is 10mm ÷ 2.1 × 0.8 = 3.8mm. The initial powder thickness is 68mm, so the minimum powder thickness is 68 - 3.8mm = 64.2mm.

[0029] Comparative Examples 1-5

[0030] The parameters were the same as in Example 1, except for the area specifications of the kiln furniture, which were 2m×1m, 1.5m×1m, 2m×0.5m, 1m×0.8m, and 2m×0.4m. The surface morphology of the kiln products was tested after firing, and the test data are shown in Table 1 below.

[0031] Table 1

[0032] Serial Number Product thickness Morphological consistency Comparative Example 1 136~147mm Consistent Comparative Example 2 138~152mm Basically the same Comparative Example 3 140~151mm Basically the same Comparative Example 4 139~152mm Inconsistent Comparative Example 5 141~153mm Inconsistent

[0033] The morphological consistency test and evaluation method is as follows: 100 kiln-fired products are selected, and their surface morphology data are tested. Fitting analysis is performed based on the surface morphology data. If the deviation is ≤5%, the consistency is considered good, denoted as "consistent"; if the deviation is 5%–10%, the consistency is considered average, denoted as "basically consistent"; and if the deviation is ≥10%, the consistency is considered poor, denoted as "inconsistent". Inconsistency negatively impacts the effectiveness of material replenishment. A similar test method is used for foamed ceramic products produced using silicon carbide as a foaming agent, employing a powder application molding method. Under the process conditions that the fired product is 3–20 cm in size, the kiln furniture specifications are based on an area ≥1m². 2 Furthermore, a width of ≥0.5m is preferable.

[0034] Example 2

[0035] This embodiment uses different combinations of materials for the top and bottom layers to give the foamed ceramic surface a decorative effect after firing. Specifically, the bottom material is applied and leveled first, then the top material is applied and leveled, and then the product is fired in the kiln. The surface morphology data of the product after firing is tested. Based on the surface morphology data, the foamed ceramic material layer in the kiln furniture is replenished with the top material before firing. After replenishment, the product is fired in the kiln to obtain a smooth foamed ceramic product.

[0036] The specific process parameters are as follows:

[0037] The bottom layer material is the powder from Example 1, and the coefficient of thermal expansion of the powder (unit / ℃) is shown in Table 2 below:

[0038] Table 2

[0039]

[0040] The bottom layer material is 48mm thick, the firing cycle is 9.5h, and the firing temperature is 1165℃; the foaming ratio is approximately 2.0.

[0041] The foaming ratio of the bottom raw material was tested as shown in Table 3 below:

[0042] Table 3

[0043] Fabric thickness (cm) 5.6 6.6 5.0 4.8 Foam thickness (cm) 11.7～12.5 14.1～15.1 9.5～10.2 9.2～9.8 Foaming ratio 2.09～2.23 2.14～2.29 1.93～2.08 1.91～2.04

[0044] For the same type of powder, the foaming ratio data and the process parameters during firing also have a certain impact. Therefore, the foaming ratio data should be based on the same batch of raw materials and the same process parameters. At the same time, a correction factor should be introduced when adding materials. The correction factor is 0.8 to 1.2.

[0045] The high-temperature viscosity of the base material was tested (spherical state under a high-temperature microscope). Specific test data are attached. Figure 1 .

[0046] Specifically, the softening temperature (DT) is 1172.0℃, the spherical temperature (ST) is 1248.0℃, the hemispherical temperature (HT) is 1359.0℃, and the flow temperature (FT) is 1435.0℃.

[0047] The chemical composition (mass percentage of oxides) of the powder used in the fabric is shown in Table 4 below:

[0048] Table 4

[0049]

[0050] Because each oxide component is rounded to two decimal places, the sum of the percentages of various components will deviate slightly from 100%.

[0051] The black pigment is produced by adjusting the iron and titanium content in the formula, resulting in a black color after firing. Because it involves the addition of other inorganic pigments, its cost is relatively low, and it is used in this embodiment. In other embodiments, other known inorganic pigments can be used as substitutes.

[0052] Super white material is a raw material with high whiteness. In this embodiment, it is used alone. In other embodiments, it can be adjusted to different colors by adding inorganic high-temperature pigments or oxide coloring methods for surface decoration. At the same time, it can also be used to produce different colors by adjusting the formula of some mineral raw materials for surface decoration. Furthermore, using known fabric technology, it can be made into granular material or linear material, which can form rich decorative effects after firing.

[0053] The coefficients of thermal expansion (unit / ℃) of the two raw materials in the fabric are shown in Table 5 below:

[0054] Table 5

[0055]

[0056] In this embodiment, the mass ratio of black material to ultra-white material in the fabric is 1:3.

[0057] The high-temperature viscosity of the fabric layer powder (spherical state under a high-temperature microscope) was tested, and the test data are attached. Figure 2 .

[0058] Specifically, the softening temperature (DT) is 1174.0℃, the spherical temperature (ST) is 1271.0℃, the hemispherical temperature (HT) is 1352.0℃, and the flow temperature (FT) is 1430.0℃.

[0059] The fabric layer thickness is 3mm, and the foaming ratio is approximately 1.3. After firing, the surface morphology of the product is tested. The deepest depression is located in the middle of the foamed ceramic board, with a depression depth of approximately 7.0mm. Therefore, when using fabric for filling, the filling thickness is 7 ÷ 1.3 × 1 = 5.38mm.

[0060] The process requirements for the powder are the same as in Example 1, namely, the particle size distribution of the base layer and the top layer, the moisture requirements during fabrication, etc., are the same as in Example 1.

[0061] After adding materials, the material is placed in the kiln for firing. The firing cycle is 9.5 hours and the firing temperature is 1165℃.

[0062] After exiting the kiln, the surface morphology was tested. The surface was smooth and the height difference was ≤3mm. It would not show through during polishing.

[0063] Without the addition of a material replenishment process, when the fabric layer is thin and the height difference is large, the bottom layer is prone to showing through during the polishing and smoothing process.

[0064] Example 3

[0065] Basically the same as in Example 2. In this example, we strictly control the temperature difference between the surface and bottom of the powder layer in the high-temperature firing section during firing. That is, in the high-temperature firing zone of 1000℃~1165℃, we control the temperature difference between the surface and bottom to be ≤30℃, and the surface temperature > the bottom temperature. The actual picture of the product after firing is attached. Figure 3 , attached Figure 3 The image shows the actual structure of the side of the foamed ceramic after firing. From the image, we can see that the surface is very flat, and the boundary between the surface layer and the bottom layer is very straight. Moreover, the boundary is well fused and there are no large through holes.

[0066] Through similar tests as in Example 2 and Example 3, we found that when the temperature difference between the fabric layer and the base layer Softening temperature (DT) is ≤10℃, and the firing temperature is also ≤10℃, the boundary line at the interface between the fabric and the base layer is clear and straight. Under the condition that the thickness of the foamed ceramic board after firing is 20-200mm, the thickness of the fabric layer can be as thin as 2mm without being transparent to the bottom. The corresponding preferred formulation components are as follows: The base material, by mass percentage of oxides, includes: SiO2: 65–69%, Al2O3: 15–17%, Fe2O3: 0–1.5%, TiO2: 0–2%, CaO: 0–2%, MgO: 0–3%, K2O: 2–4%, Na2O: 2–4%, LOI: 2–4%; the fabric, by mass percentage of oxides, includes: SiO2: 63–69%, Al2O3: 15–19%, Fe2O3: 0.5–3%, TiO2: 0–0.5%, CaO: 1–3%, MgO: 2–5%, K2O: 2–5%, Na2O: 2–5%, LOI: 2–6%. LOI is the loss on ignition.

[0067] The boundary line between the fabric and the base material is clear and straight, which also facilitates subsequent processing. For example, it is possible to cut along the boundary line near the bottom layer and fire it once to obtain foamed ceramic products with two different decorative effects.

[0068] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A foamed ceramic production process, using silicon carbide as a foaming agent, characterized in that, The process includes the following steps: First, the surface flatness of the foamed ceramic products after they come out of the kiln is tested to determine the surface morphology data of the foamed ceramic products after they come out of the kiln. Then, based on the surface morphology data, the foamed ceramic raw material layer obtained by the molding process before firing in the same batch is replenished. The raw material used for replenishment is the same as the surface raw material composition of the foamed ceramic raw material layer. The replenishment area is the concave area of ​​the foamed ceramic products after they come out of the kiln. After replenishment, the morphology of the raw material layer is maintained, and the product is fired in the kiln. The foamed ceramic raw materials used in the molding process include at least a base material and a surface material. The molding process is as follows: first, the base material is spread in the kiln furniture and leveled to form a base material layer; then, the surface material is spread in the kiln furniture and leveled to form a surface material layer. The absolute value of the difference between the softening temperature of the base material and the softening temperature of the fabric is ≤10℃. The base material, by mass percentage of oxides, comprises: SiO2: 65-69%, Al2O3: 15-17%, Fe2O3: 0-1.5%, TiO2: 0-2%, CaO: 0-2%, MgO: 0-3%, K2O: 2-4%, Na2O: 2-4%, LOI: 2-4%; The fabric, by mass percentage of oxides, comprises: SiO2: 63-69%, Al2O3: 15-19%, Fe2O3: 0.5-3%, TiO2: 0-0.5%, CaO: 1-3%, MgO: 2-5%, K2O: 2-5%, Na2O: 2-5%, LOI: 2-6%.

2. The foamed ceramic production process as described in claim 1, characterized in that, The thickness of the filling material is: the depth of the depression at the filling point / the foaming ratio of the raw material used for the filling material × 0.8 to 1.2, where the foaming ratio is: the volume of the raw material after molding and firing / the volume of the raw material before molding and firing.

3. The foamed ceramic production process as described in claim 2, characterized in that, The foaming ratio is 1.2 to 2.

5.

4. The foamed ceramic production process as described in claim 1, characterized in that, The firing process is as follows: The firing cycle is 8 to 13.5 hours, and the firing temperature is 1160 to 1175℃. In the high-temperature firing zone, the surface temperature is greater than the bottom temperature, and the temperature difference between the two is ≤30℃.

5. A foamed ceramic produced using the foamed ceramic production process described in any one of claims 1 to 4.

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