A process for producing a foamed ceramic plate

Abstract

The application discloses a production process of foamed ceramic plate, which comprises the following steps: spreading ceramic powder with a thickness of greater than or equal to 5 mm in a refractory kiln, and scraping; spreading foamed ceramic powder on the ceramic layer, and scraping; sending into a kiln for firing, removing the refractory kiln after cooling out of the kiln, thereby obtaining the foamed ceramic plate, and performing edge grinding and / or cutting processing according to a required shape to obtain a finished product; wherein the linear thermal expansion coefficient difference of the ceramic layer raw material and the foamed ceramic layer raw material at 30-200 DEG C and 30-600 DEG C is not greater than 0.7*10 ‑6 K ‑1 The foamed ceramic plate prepared by the application has high bonding degree, is not easy to fall off, has long service life, stable foaming, and has a decorative effect, and can be processed into various ceramic plate materials through simple cutting according to needs, thereby saving fuel consumption cost, greatly improving the utilization rate of materials and the kiln, and improving the output value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building ceramics, in particular to a production process of foamed ceramic plate. BACKGROUND

[0002] Foamed ceramics have the functions of light weight, heat preservation, and flame retardation, and have low requirements on raw materials, and can use a large amount of waste materials generated in ceramic production, and are a kind of green and environmentally friendly building materials. However, the surface of foamed ceramics after polishing and grinding processing is honeycomb-shaped, and generally does not have decorative effect. In order to obtain a surface with decorative effect, three methods can be generally used:

[0003] I. After the foamed ceramic plate is processed, the surface is decorated, such as surface spraying paint or real stone paint. The service life of such products is limited, and the decorative layer is easy to fall off;

[0004] II. After the foamed ceramic plate is processed, glue is applied to bond stone thin plates, ceramic thin plates or calcium-silicon plates on the surface. The glue in such products is prone to aging, especially when used outdoors, the service life is short, and the surface decorative layer is easy to fall off;

[0005] III. Microcrystalline material is used for decoration, a microcrystalline material layer and a foamed ceramic layer are formed by two times of material distribution, and the product is integrally sintered. A small amount of delamination in foamed ceramic industrial production is allowed, which is generally less than 10%. However, the cost of microcrystalline material is high, the yield is low, and the expansion coefficients of the two kinds of raw materials are not easy to match, so the product is prone to a large amount of cracking (more than 10%).

[0006] Chinese patent CN110395969A discloses a microcrystalline composite coal gangue-based foamed ceramic insulation board and a preparation method thereof, which uses microcrystalline glass frit powder as a decorative layer and foamed material as a foamed layer to solve the combination problem of the decorative layer and the foamed layer. However, the production cycle and energy consumption of the frit, and the matching problem of the thermal expansion coefficient lead to high production cost, and the pattern and color of the frit are single, the decorative individuality is low, which limits the market promotion of the product.

[0007] Chinese patent CN114105670A discloses a preparation method of rock plate composite light insulation board, which uses rock plate and foamed layer for compounding and achieves decorative effect by secondary sintering. The combination is excellent, but the production chain cost is high due to the secondary sintering of the rock plate, and the rock plate only has the pattern and effect of the rock plate, and the rock plate will lose color and surface effect in the secondary sintering process, which finally affects the decorative effect of the product.

[0008] In view of the above technical problems, it is necessary to propose a new production process of foamed ceramic plate. SUMMARY

[0009] The main purpose of the present application is to provide a foamed ceramic plate production process, which has low production cost, good decorative effect, can obtain various ceramic products by one-time firing, greatly improves the utilization rate of materials and kiln, and improves the output value.

[0010] To achieve the above-mentioned purpose, the present application provides a foamed ceramic plate production process, comprising the following steps:

[0011] (1) Laying ceramic layer: spreading ceramic powder with a thickness of ≥5mm in the refractory kiln, and scraping flat;

[0012] (2) Laying foamed ceramic layer: spreading foamed ceramic powder on the ceramic layer, and scraping flat;

[0013] (3) Sending into the kiln for firing, removing the refractory kiln after cooling out of the kiln, to obtain the foamed ceramic plate;

[0014] (4) Grinding and / or cutting the foamed ceramic plate obtained in step (3) according to the required shape to obtain the finished product;

[0015] Among them, the linear thermal expansion coefficient α1 of the ceramic layer raw material in step (1) meets the following requirements:

[0016] 30-200℃: 6.0×10 -6 K -1 ≤α1≤6.6×10 -6 K -1 ; 30-600℃: 7.0×10 -6 K -1 ≤α1≤7.5×10 -6 K -1 ;

[0017] The linear thermal expansion coefficient α2 of the foamed ceramic layer raw material in step (2) meets the following requirements:

[0018] 30-200℃: 5.7×10 -6 K -1 ≤α2≤6.4×10 -6 K -1 ; 30-600℃: 6.7×10 -6 K -1 ≤α2≤7.6×10 -6 K -1 .

[0019] The production process of the foamed ceramic plate only adopts multiple layers of cloth, does not need to be pressed into a brick body or sprayed with glaze, and through matching the linear thermal expansion coefficients of the raw materials of the multiple layers of powder, the multiple layers of loose powder are directly combined through solid phase reaction in the firing process, and the combination degree is high after firing, and cracking and other phenomena do not occur, the service time is long, the foamed ceramic plate with a decorative effect is fired at one time, and the fuel consumption cost is saved. Meanwhile, the foamed ceramic plate produced by the production process can obtain at least two types of ceramic plate materials after cutting processing, at least two products are obtained under the same firing system and firing period, the utilization rate of materials and kiln is greatly improved, and the production value is improved.

[0020] Preferably, the linear thermal expansion coefficient of the ceramic layer raw material α1 meets the following requirements:

[0021] 30-100℃: 5.9×10 -6 K -1 ≤α1≤6.6×10 -6 K -1 ; 30-200℃: 6.0×10 -6 K -1 ≤α1≤6.6×10 -6 K -1 ; 30-300℃: 6.3×10 -6 K -1 ≤α1≤6.8×10 -6 K -1 ; 30-400℃: 6.5×10 -6 K -1 ≤α1≤6.9×10 - 6 K -1 ; 30-500℃: 6.7×10 -6 K -1 ≤α1≤7.1×10 -6 K -1 ; 30-600℃: 7.0×10 -6 K -1 ≤α1≤7.5×10 -6 K -1 ; 30-700℃: 7.0×10 -6 K -1 ≤α1≤7.6×10 -6 K -1 ; 30-800℃: 8.2×10 -6 K -1 ≤α1≤8.5×10 -6 K -1 ;

[0022] The linear thermal expansion coefficient a2 of the foamed ceramic layer raw material meets the following requirements:

[0023] 30-100℃: 5.5x10 -6 K -1 ≤a2≤6.2x10 -6 K -1 ; 30-200℃: 5.7x10 -6 K -1 ≤a2≤6.4x10 -6 K -1 ; 30-300℃: 6.0x10 -6 K -1 ≤a2≤6.7x10 -6 K -1 ; 30-400℃: 6.2x10 -6 K -1 ≤a2≤6.9x10 - 6 K -1 ; 30-500℃: 6.6x10 -6 K -1 ≤a2≤7.2x10 -6 K -1 ; 30-600℃: 6.7x10 -6 K -1 ≤a2≤7.6x10 -6 K -1 ; 30-700℃: 6.9x10 -6 K -1 ≤a2≤7.6x10 -6 K -1 ; 30-800℃: 7.1x10 -6 K -1 ≤a2≤8.4x10 -6 K -1 .

[0024] The dense structures of the two layers of ceramic layer and foamed layer are different, resulting in high heat dissipation efficiency of the ceramic layer, while the foamed layer has a certain heat preservation effect due to the honeycomb-like porous structure in its internal structure, so the heat dissipation efficiency is low. Therefore, by controlling the linear thermal expansion coefficients of the ceramic layer raw material and the foamed ceramic layer raw material in the low temperature section of 100-800℃, the situation of excessive stress and cracking and delamination during the firing process in the low temperature section is further avoided.

[0025] Preferably, the difference between the linear thermal expansion coefficients of the ceramic layer raw material and the foamed ceramic layer raw material at 30-200℃ and 30-600℃ is ≤0.7x10 -6 K -1By adjusting the matching degree of the thermal expansion coefficient of the ceramic layer and the foamed ceramic layer raw materials, the ceramic layer formula and the foamed ceramic layer formula are adapted, and after firing, the ceramic layer does not deform and has good flatness.

[0026] Preferably, the loss on ignition of the ceramic layer raw material and the foamed ceramic layer raw material is ≤3%wt. The shrinkage caused by excessive loss on ignition of the powder can be effectively reduced, thereby avoiding the phenomenon of bottom powder leakage.

[0027] Preferably, the ceramic layer raw material components include, in mass fraction: 9033 zirconium white fusion block 10 parts, burned talc 5 parts, microcrystalline fusion block 20 parts, potassium sodium stone powder 35 parts, potassium feldspar 15 parts, sodium feldspar 10 parts, ball clay 5 parts, sodium tripolyphosphate 0.25 parts, sodium carboxymethyl cellulose 0.15 parts;

[0028] The foamed ceramic layer raw material components include, in mass fraction: 9033 zirconium white fusion block 4 parts, pressed mud 15 parts, foamed ceramic waste 20 parts, magnesia clay 4 parts, river sand tailings 32 parts, shirong tailings 5 parts, construction slag 20 parts, body enhancer 0.25 parts, green silicon 0.3 parts.

[0029] Preferably, the cutting process of step (4) includes the step of cutting the foamed ceramic plate, and the cutting step is based on the boundary line between the sintered ceramic layer and the foamed ceramic layer, and the cutting line is located on one side of the foamed ceramic layer. Two products, foamed ceramic plate material and foamed ceramic plate material with ceramic layer, can be obtained respectively. According to actual needs, further surface treatment such as polishing, waxing or sandblasting can be performed on the ceramic layer. Two different types of ceramic plate materials are obtained by one firing, saving fuel consumption cost.

[0030] Preferably, the foamed ceramic layer includes at least two first foamed layers and second foamed layers that exhibit different decorative effects after firing, and the laying process is to lay the first foamed layer powder first, and then lay the second foamed layer powder after leveling. Three different types of ceramic plate materials can be obtained after cutting, which are foamed ceramic plate material with ceramic layer on the surface, foamed ceramic plate material formed by sintering the first foamed layer raw material, and composite foamed ceramic plate material formed by sintering the first foamed layer and the second foamed layer. By adjusting the formula, the first foamed layer and the second foamed layer can have two different decorative effects after sintering.

[0031] Preferably, the powder of the ceramic layer is obtained by ball milling and spray granulation;

[0032] The ball milling process parameters are: slurry fineness 0.8-1.0%, slurry moisture ≤35% by weight;

[0033] The powder of the ceramic layer has a water content of 5-5.5%, and the ceramic layer has a laying thickness of 10-25mm.

[0034] By regulating the technical parameters of the ceramic layer powder, the stability of the thickness of the finished product after firing is ensured. The laying thickness of the ceramic powder directly affects the thickness of the ceramic layer after firing. The thickness of the spread ceramic powder is controlled to be 10-25mm, so that the thickness of the ceramic layer after firing is 5-15mm, which can meet the performance requirements of different application scenarios of the product, has good decorative effect, and also avoids using a large amount of ceramic raw materials, thereby reducing the cost of raw materials.

[0035] Preferably, the powder of the foamed ceramic layer is obtained by ball milling, spray granulation:

[0036] The ball milling process parameters are: slurry fineness 0.8-1.0%, slurry moisture ≤35% by weight;

[0037] The green strength of the powder of the foamed ceramic layer is higher than 1.3Mpa, the water content of the powder is 5.5-6.0%, the bulk density is 0.87-0.88g / ml, and the powder particles of 20 mesh and below 100 mesh are ≤1.5% respectively;

[0038] The laying thickness of the foamed ceramic layer is 25-75mm.

[0039] By regulating the technical parameters of the foamed ceramic layer powder, the stability of the laying thickness and the thickness of the finished product after firing is ensured, and each layer is smoothly foamed, the boundary is clear after firing, and the performance fluctuation of the powder is effectively prevented to cause the laying amount to be inconsistent, thereby affecting the thickness of the plate after firing.

[0040] By controlling the laying thickness of the ceramic raw material of each layer, the total thickness after firing is controlled in the range of 95-115mm, so as to ensure the stability of the thickness of a single product of the three kinds of plates after processing and to meet the use requirements of different application scenarios.

[0041] Preferably, the step (2) and the step (3) further comprise a step of scattering low-temperature raw materials capable of forming a protective layer after the firing of the step (3) on the foamed ceramic layer, the components of the low-temperature raw materials comprising, in terms of mass percentage of oxides: SiO2: 54.35-68.96%, Al2O3: 8.45-14.34%, Fe2O3: 0.2-0.6%, TiO2: 0.04-0.2%, CaO: 5.04-18.4%, MgO: 1.1-3.1%, K2O: 0.5-5.8%, Na2O: 3.5-9%, BaO: 0.02-3.01%, ZnO: 0.05-8%, L.O.I: 0.2-3%. Some low-temperature powders can be scattered on the surface of the foamed ceramic layer in the form of dry powder or high-concentration glaze slurry, so that the surface of the product after firing has stain-proof performance.

[0042] Compared with the prior art, the present application has at least the following beneficial effects:

[0043] 1. The production process of the present application can combine the ceramic layer and the foamed ceramic layer in one firing, which is stable, has no cracking and delamination, and saves fuel consumption cost.

[0044] 2. The foamed ceramic blank produced by the production process of the present application has high surface flatness and clear boundaries, and after cutting and processing, a variety of foamed ceramic plates with different decorative effects can be obtained.

[0045] 3. The low-temperature powders with stain-proof effect are scattered on the surface of the foamed ceramic layer, so that the surface of the foamed ceramic after firing has stain-proof performance. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other related drawings according to these drawings without creative labor.

[0047] Figure 1 Structure schematic view of the foamed ceramic plate prepared for Example 6;

[0048] Figure 2 Cutting and processing schematic view of the foamed ceramic plate prepared for Example 6 (a: foamed ceramic plate before cutting and processing, A and B are cutting and processing lines; b: ceramic plate material I, ceramic plate material II and ceramic plate material III obtained after cutting and processing).

[0049] In the drawings, 1 is a second foamed layer, 2 is a first foamed layer, and 3 is a ceramic layer.

[0050] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work are within the protection scope of the present application.

[0052] In addition, the technical solutions in each embodiment can be combined with each other, but the combination of the technical solutions should be based on the fact that a person of ordinary skill in the art can realize the combination. When the combination of the technical solutions appears to be contradictory or unachievable, it should be considered that the combination of the technical solutions does not exist and is not within the protection scope of the present application.

[0053] The present application provides a production process of foamed ceramic plate, comprising the following steps:

[0054] (1) laying ceramic layer: spreading ceramic powder with thickness ≥5mm in refractory kiln, and scraping flat;

[0055] The powder of the ceramic layer is obtained by ball milling, slurry preparation and spray granulation;

[0056] The ball milling process parameters are: slurry fineness 0.8-1.0%, slurry moisture ≤35% by weight percentage;

[0057] The water content of the powder of the ceramic layer is 5-5.5%, and preferably, the thickness of the ceramic layer is 10-25mm.

[0058] (2) laying foamed ceramic layer: spreading foamed ceramic powder on the ceramic layer, and scraping flat;

[0059] The powder of the foamed ceramic layer is obtained by ball milling, slurry preparation and spray granulation:

[0060] The ball milling process parameters are: slurry fineness 0.8-1.0%, slurry moisture ≤35% by weight percentage;

[0061] The green strength of the powder of the foamed ceramic layer is higher than 1.3Mpa, the water content of the powder is 5.5-6.0%, the bulk density is 0.87-0.88g / ml, and the powder particles of more than 20 mesh and less than 100 mesh are ≤1.5% respectively;

[0062] The thickness of the foamed ceramic layer is 25-75mm.

[0063] (3) put into the kiln and fired, the firing temperature is 1160-1170℃, the firing period is 8-13.5h, after cooling out of the kiln, remove the refractory kiln furniture, and the foamed ceramic plate is obtained;

[0064] (4) according to the required shape, the foamed ceramic plate obtained in step (3) is edge polished and / or cut to obtain the finished product;

[0065] In step (1), the linear thermal expansion coefficient α1 of the ceramic layer raw material meets the following requirements:

[0066] 30-100℃: 5.9×10 -6 K -1 ≤α1≤6.6×10 -6 K -1 ; 30-200℃: 6.0×10 -6 K -1 ≤α1≤6.6×10 -6 K -1 ; 30-300℃: 6.3×10 -6 K -1 ≤α1≤6.8×10 -6 K -1 ; 30-400℃: 6.5×10 -6 K -1 ≤α1≤6.9×10 - 6 K -1 ; 30-500℃: 6.7×10 -6 K -1 ≤α1≤7.1×10 -6 K -1 ; 30-600℃: 7.0×10 -6 K -1 ≤α1≤7.5×10 -6 K -1 ; 30-700℃: 7.0×10 -6 K -1 ≤α1≤7.6×10 -6 K -1 ; 30-800℃: 8.2×10 -6 K -1 ≤α1≤8.5×10 -6 K -1 ;

[0067] In step (2), the linear thermal expansion coefficient α2 of the foamed ceramic layer raw material meets the following requirements:

[0068] 30-100℃: 5.5×10 -6 K -1 ≤α2≤6.2×10-6 K -1 ; 30-200℃: 5.7 x 10 -6 K -1 ≤ α2≤ 6.4 x 10 -6 K -1 ; 30-300℃: 6.0 x 10 -6 K -1 ≤ α2≤ 6.7 x 10 -6 K -1 ; 30-400℃: 6.2 x 10 -6 K -1 ≤ α2≤ 6.9 x 10 - 6 K -1 ; 30-500℃: 6.6 x 10 -6 K -1 ≤ α2≤ 7.2 x 10 -6 K -1 ; 30-600℃: 6.7 x 10 -6 K -1 ≤ α2≤ 7.6 x 10 -6 K -1 ; 30-700℃: 6.9 x 10 -6 K -1 ≤ α2≤ 7.6 x 10 -6 K -1 ; 30-800℃: 7.1 x 10 -6 K -1 ≤ α2≤ 8.4 x 10 -6 K -1 .

[0069] The difference between the linear thermal expansion coefficients of the ceramic layer raw material and the foamed ceramic layer raw material at 30-200℃ and 30-600℃ is ≤ 0.7 x 10 -6 K -1 .

[0070] The loss on ignition of the ceramic layer raw material and the foamed ceramic layer raw material is ≤ 3% wt.

[0071] It should be noted that the thickness of the ordinary ceramic remains basically unchanged during the sintering process, and the width presents a shrinkage trend; while the foamed ceramic has a tendency to expand with the increase of temperature during the sintering process, and presents a shrinkage trend when cooled, and the volume after sintering can reach 1.5-3 times of the original size. Therefore, the ordinary ceramic and the foamed ceramic have different size change trends during the sintering process, which makes the production process of the composite board difficult, and is easy to form cracking, deformation, bulging and other phenomena at the joint of the ceramic layer and the foamed ceramic layer. The present application strictly controls the linear thermal expansion coefficient of the ceramic layer raw material and the foamed ceramic layer raw material and the difference between the linear thermal expansion coefficients of the two at 30-200 DEG C and 30-600 DEG C, to ensure that the shrinkage of the ceramic layer and the foamed ceramic layer is basically consistent during the cooling process, and the ceramic layer and the foamed ceramic layer are combined stably after sintering, and have a long service life. The ceramic layer and the foamed ceramic layer are sintered at one time, which saves energy consumption and reduces production cost.

[0072] Further, in an embodiment of the present application, the ceramic layer raw material components include, in mass fraction: 9033 zirconium white fusion block 10 parts, calcined talc 5 parts, microcrystalline fusion block 20 parts, potassium sodium stone powder 35 parts, potassium feldspar 15 parts, sodium feldspar 10 parts, ball clay 5 parts, sodium tripolyphosphate 0.25 parts, sodium carboxymethyl cellulose 0.15 parts;

[0073] The foamed ceramic layer raw material components include, in mass fraction: 9033 zirconium white fusion block 4 parts, pressed mud 15 parts, foamed ceramic waste 20 parts, magnesia clay 4 parts, river sand tailings 32 parts, shengrong tailings 5 parts, construction waste 20 parts, green body reinforcing agent 0.25 parts, green silicon 0.3 parts.

[0074] Specifically, in the present application, the ceramic layer can be made of ordinary ceramic raw materials. There is no limitation on the specific formula of the foamed ceramic layer, and any existing foamed ceramic layer can be selected by those skilled in the art according to actual needs.

[0075] Further, the cutting process of step (4) includes the step of cutting the foamed ceramic plate, and the cutting step is based on the boundary line of the sintered ceramic layer and the foamed ceramic layer, and the cutting line is located on one side of the foamed ceramic layer. Two different ceramic plates can be obtained.

[0076] Further, in an embodiment of the present application, the foamed ceramic layer includes a first foamed layer and a second foamed layer which present different decorative effects after sintering, and the laying process is to lay the first foamed layer powder first, and then lay the second foamed layer powder after scraping. Once sintering can obtain a ceramic green body with a three-layer structure, and three different ceramic plates can be obtained through transverse cutting process.

[0077] The production process described in this invention can produce a variety of ceramic slabs in a single firing, which greatly improves the utilization rate of ceramic materials and kilns and reduces production costs.

[0078] Furthermore, in this invention, to improve the anti-fouling performance of the foamed ceramic surface layer, a step of spreading a low-temperature raw material that can form a protective layer after firing in step (3) is included between step (2) and step (3). The components of the low-temperature raw material, in terms of the mass percentage of oxides, include: SiO2: 54.35-68.96%, Al2O3: 8.45-14.34%, Fe2O3: 0.2-0.6%, TiO2: 0.04-0.2%, CaO: 5.04-18.4%, MgO: 1.1-3.1%, K2O: 0.5-5.8%, Na2O: 3.5-9%, BaO: 0.02-3.01%, ZnO: 0.05-8%, LOI: 0.2-3%.

[0079] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0080] The specific chemical composition of each ceramic preparation raw material in the following embodiments is provided in the table below (in mass percentage, unit is %):

[0081]

[0082]

[0083] Raw Material Name SiO2 Al2O3 Fe2O3 TiO2 CaO MgO K2O Na2O L.O.I ZrO2 ZnO 9033 zircon white frit 61.02 6.18 0.17 0.37 10.94 3.58 4.09 0.01 0.34 6.3 6.16 Microcrystalline frit 58.97 8.45 0.2 1.17 18.4 2.1 0.65 5.28 0.28 - 1.63

[0084] Note: If the chemical composition of the raw materials in the table above is less than 100%, it is mainly due to the presence of other undetected impurities.

[0085] The green silicon used in the examples is silicon carbide with a purity of 98.5% or higher, purchased from Foshan Changyuan New Materials Co., Ltd.; the sodium tripolyphosphate used is purchased from Jingdezhen Jiatao Ceramic Materials Co., Ltd.; the sodium carboxymethyl cellulose used is purchased from Foshan Chancheng Yingyuan Trading Co., Ltd.; and the green body reinforcing agent is purchased from Foshan Xinjinhui Economic and Trade Co., Ltd.

[0086] 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.

[0087] The test standard for the linear thermal expansion coefficient of the ceramic raw material and the foamed ceramic raw material is the national standard GB / T7320-2018, and the test method is the top rod method known in the art.

[0088] The ceramic layer raw material components and the foamed ceramic layer raw material components in examples 1-5 are shown in the following table (in mass fraction):

[0089]

[0090]

[0091]

[0092] The ceramic layer raw material components and the foamed ceramic layer raw material components are accounted for oxides in mass percentage as shown in the following table (in %):

[0093]

[0094] The linear thermal expansion coefficients of the ceramic layer raw material and the foamed ceramic layer raw material are shown in the following table:

[0095]

[0096]

[0097]

[0098]

[0099] Note: The detection error range of the linear thermal expansion coefficient in the above table is ±0.02x10 -6 / K.

[0100] L.O.I represents the loss on ignition, and oxides of elements such as C, N, S, and H are gaseous under high temperature conditions. It is known to those skilled in the art that in the actual firing process, there are impurities that are not detected, resulting in the total weight of the chemical composition of the raw material being less than 100%. The above chemical components are exemplary, and both the ceramic layer raw material and the foamed ceramic layer raw material can use mineral raw materials known in the art. Those skilled in the art can adjust the specific formula of the ceramic layer and the foamed ceramic layer according to the actual situation within the range of the linear thermal expansion coefficient required by the present embodiment.

[0101] The specific production process of examples 1-5 is as follows:

[0102] Example 1

[0103] A foamed ceramic plate production process, comprising the following steps:

[0104] (1) According to the above mass fraction, the ceramic layer raw material is prepared into ceramic powder, and the process parameters of the ceramic powder are as follows: slurry fineness 0.8%, slurry moisture 35% by weight, and powder moisture 5%; the ceramic powder with a thickness of 15 mm is spread in the refractory kiln, and then is scraped flat;

[0105] (2) According to the above mass fraction, the foamed ceramic layer raw material is prepared into foamed ceramic powder, and the process parameters of the foamed ceramic powder are as follows: slurry fineness 0.8%, slurry moisture 30% by weight, powder moisture 5.5%, bulk density 0.87 g / ml, and powder particles of 20 mesh and below 100 mesh are less than or equal to 1.5% respectively, and the green strength is higher than 1.3 MPa; the prepared foamed ceramic powder is spread on the ceramic layer with a thickness of 65 mm, and then is scraped flat;

[0106] (3) The prepared ceramic layer and foamed ceramic layer are sent into a kiln for firing, the firing temperature is 1160°C, the firing period is 13.5 h, and after the kiln is cooled and the refractory kiln is removed, a foamed ceramic plate is obtained;

[0107] (4) After being cooled for 24 h, the ceramic layer and the foamed ceramic layer are cut along the middle line according to the boundary line, the ceramic layer is polished and polished, and two kinds of ceramic plates are obtained.

[0108] Example 2

[0109] A foamed ceramic plate production process comprises the following steps:

[0110] (1) According to the above mass fraction, the ceramic layer raw material is prepared into ceramic powder, and the process parameters of the ceramic powder are as follows: slurry fineness 0.9%, slurry moisture 30% by weight, and powder moisture 5.2%; the ceramic powder with a thickness of 15 mm is spread in the refractory kiln, and then is scraped flat;

[0111] (2) According to the above mass fraction, the foamed ceramic layer raw material is prepared into foamed ceramic powder, and the process parameters of the foamed ceramic powder are as follows: slurry fineness 0.8%, slurry moisture 35% by weight, powder moisture 5.8%, bulk density 0.87 g / ml, and powder particles of 20 mesh and below 100 mesh are less than or equal to 1.5% respectively, and the green strength is higher than 1.3 MPa; the prepared foamed ceramic powder is spread on the ceramic layer with a thickness of 65 mm, and then is scraped flat;

[0112] (3) The prepared ceramic layer and foamed ceramic layer are sent into a kiln for firing, the firing temperature is 1165°C, the firing period is 13.5 h, and after the kiln is cooled and the refractory kiln is removed, a foamed ceramic plate is obtained;

[0113] (4) After being cooled for 24 h, the ceramic layer and the foamed ceramic layer are cut along the middle line according to the boundary line, the ceramic layer is polished and polished, and two kinds of ceramic plates are obtained.

[0114] Example 3

[0115] A foamed ceramic plate production process, comprising the following steps:

[0116] (1) According to the above mass fraction, the ceramic layer raw material is prepared into ceramic powder, and the process parameters of the ceramic powder are: slurry fineness 1.0%, slurry moisture 35% by weight, and powder moisture 5.5%; the ceramic powder with a thickness of 15mm is spread in the refractory kiln, and then scraped flat;

[0117] (2) According to the above mass fraction, the foamed ceramic layer raw material is prepared into foamed ceramic powder, and the process parameters of the foamed ceramic powder are: slurry fineness 0.9%, slurry moisture 35% by weight, powder moisture 6.0%, bulk density 0.87g / ml, and powder particles above 20 mesh and below 100 mesh are ≤1.5% respectively, and the green strength is higher than 1.3Mpa; the prepared foamed ceramic powder is spread on the ceramic layer with a thickness of 65mm, and then scraped flat;

[0118] (3) Put into the kiln for firing, the firing temperature is 1160℃, the firing period is 13.5h, after cooling out of the kiln, the refractory kiln is removed, and the foamed ceramic plate is obtained;

[0119] (4) After cooling for 24h, cut along the center line according to the boundary line of the ceramic layer and the foamed ceramic layer, and polish the ceramic layer, then two kinds of ceramic plates are obtained.

[0120] Example 4

[0121] A foamed ceramic plate production process, comprising the following steps:

[0122] (1) According to the above mass fraction, the ceramic layer raw material is prepared into ceramic powder, and the process parameters of the ceramic powder are: slurry fineness 0.9%, slurry moisture 30% by weight, and powder moisture 5%; the ceramic powder with a thickness of 15mm is spread in the refractory kiln, and then scraped flat;

[0123] (2) According to the above mass fraction, the foamed ceramic layer raw material is prepared into foamed ceramic powder, and the process parameters of the foamed ceramic powder are: slurry fineness 1.0%, slurry moisture 30% by weight, powder moisture 5.5%, bulk density 0.88g / ml, and powder particles above 20 mesh and below 100 mesh are ≤1.5% respectively, and the green strength is higher than 1.3Mpa; the prepared foamed ceramic powder is spread on the ceramic layer with a thickness of 65mm, and then scraped flat;

[0124] (3) Put into the kiln for firing, the firing temperature is 1165℃, the firing period is 13.5h, after cooling out of the kiln, the refractory kiln is removed, and the foamed ceramic plate is obtained;

[0125] (4) After cooling for 24h, cutting along the middle line with the boundary between the ceramic layer and the foamed ceramic layer as the reference, and polishing the ceramic layer, two kinds of ceramic plates are obtained.

[0126] Example 5

[0127] A foamed ceramic plate production process, comprising the following steps:

[0128] (1) The ceramic layer raw materials are prepared into ceramic powder according to the above-mentioned mass fractions. The process parameters of the ceramic powder are as follows: slurry fineness 1.0%, slurry moisture 35% by weight, and powder moisture 5.5%; the ceramic powder with a thickness of 15mm is spread and leveled in a refractory kiln.

[0129] (2) The foamed ceramic layer raw materials are prepared into foamed ceramic powder according to the above-mentioned mass fractions. The process parameters of the foamed ceramic powder are as follows: slurry fineness 0.8%, slurry moisture 35% by weight, powder moisture 6.0%, bulk density 0.88g / ml, and powder particles of more than 20 mesh and less than 100 mesh ≤1.5% respectively, and green strength higher than 1.3Mpa; the prepared foamed ceramic powder is spread on the ceramic layer with a thickness of 65mm and leveled.

[0130] (3) The foamed ceramic plate is obtained by sending into a kiln for firing at a firing temperature of 1160℃ for a firing period of 13.5h, and removing the refractory kiln after cooling out of the kiln.

[0131] (4) After cooling for 24h, cutting along the middle line with the boundary between the ceramic layer and the foamed ceramic layer as the reference, and polishing the ceramic layer, two kinds of ceramic plates are obtained.

[0132] Comparative Example 1

[0133] Comparative Example 1 adopts the same parameters and preparation steps as Example 3, and the only difference is that the ceramic layer raw material components are different, which results in a loss on ignition of the ceramic layer raw material greater than 5%wt. The ceramic layer raw material components in mass fractions are shown in the following table:

[0134]

[0135]

[0136] The ceramic layer raw material components are calculated as oxides in mass percentages as shown in the following table:

[0137]

[0138] Comparative Example 2

[0139] Comparative Example 2 uses the same parameters and preparation steps as Example 3, with the exception that the foamed ceramic layer raw material composition is different, resulting in a loss on ignition of the foamed ceramic layer raw material greater than 5% by weight. The foamed ceramic layer raw material composition is shown in the following table in mass parts:

[0140]

[0141] The foamed ceramic layer raw material composition is accounted for as oxides in mass percent as shown in the following table (in %):

[0142]

[0143] Comparative Example 3

[0144] The same parameters and preparation steps as Example 3 are used, with the exception that the ceramic powder process parameters are: the slurry fineness is 2.0%, the slurry moisture is 35% by weight; the ceramic layer powder moisture is 8.5%, and the ceramic layer thickness is 15 mm.

[0145] Comparative Example 4

[0146] The same parameters and preparation steps as Example 3 are used, with the exception that the foamed ceramic powder process parameters are: the foamed ceramic powder milling process parameters are: the slurry fineness is 1.5%, the slurry moisture is 35% by weight; the foamed ceramic layer green strength is greater than 1.3 MPa, the powder moisture is 7.5%, the bulk density is 0.82 g / ml, and the powder particle size of 20 mesh or more and 100 mesh or less is 3%.

[0147] The properties of the foamed ceramic boards prepared in Examples 1-5 and Comparative Examples 1-4 are tested, and the comparison results are shown in Table 1.

[0148] Table 1

[0149] Sample Ceramic layer surface flatness Interlayer cracking and delamination Example 1 0.23% (Class 1) No cracking and delamination Example 2 0.21% (Class 1) No cracking and delamination Example 3 0.30% (Class 1) No cracking and delamination Example 4 0.34% (Class 1) No cracking and delamination Example 5 0.25% (Class 1) No cracking and delamination Comparative Example 1 0.65% (Class 3) Very little cracking and delamination (about 5%) Comparative Example 2 0.36% (Class 2) Very little cracking and delamination (about 2%) Comparative Example 3 0.41% (Class 2) Very little cracking and delamination (about 4%) Comparative Example 4 0.35% (Class 1) No cracking and delamination

[0150] Note: 1) The surface flatness is referenced to its short side, and ceramic tiles generally require a deviation of within 0.2%, and for composite board products, due to their thickness, it can be appropriately relaxed to 0.5-0.8%, here we set the deviation range of 0.2-0.35% as first class, the deviation range of 0.36-0.5% as second class, and the deviation range of 0.51-0.8% as third class; 2) A small amount of delamination cracking is allowed in industrial production, and generally less than 10% can be considered to have good industrialization characteristics. We correspond to this as the detection standard.

[0151] As shown in Table 1, the deviation of the surface flatness of the foamed ceramic plate prepared in Examples 1-5 is in the range of 0.2-0.35%, the ceramic layer and the foamed ceramic layer are firmly combined, and there is no cracking and delamination phenomenon, and the surface flatness is good. It can be seen that, by regulating the component ratio of the ceramic raw material and the foamed ceramic raw material, the linear thermal expansion coefficient of the ceramic raw material is matched with the linear thermal expansion coefficient of the foamed ceramic raw material, the ceramic layer and the foamed ceramic layer have high bonding degree, and the surface flatness is good. Especially, when the difference between the linear thermal expansion coefficients of the ceramic layer raw material and the foamed ceramic layer raw material at 30-200℃ and 30-600℃ is ≤0.7×10 -6 K -1 , the ceramic layer and the foamed ceramic layer have higher bonding degree and better comprehensive performance.

[0152] The loss on ignition of the ceramic layer raw material in Comparative Example 1 is too large, and there is a small amount of cracking and delamination (about 5%) between the ceramic layer and the foamed ceramic layer after being taken out of the kiln, and the deviation of the surface flatness is greater than 0.5%, and the surface flatness is reduced. The loss on ignition of the foamed ceramic layer raw material in Comparative Example 2 is too large, which leads to an increase in shrinkage, so that the powder oxidation time is too long, the foamed layer temperature is too high, the sintering degree and the foaming effect are slightly poor, the ceramic layer and the foamed ceramic layer are not synchronized in bonding and shrinkage, and a small amount of cracking and delamination (about 2%) occurs after being taken out of the kiln and standing for 24h. This shows that, by controlling the loss on ignition of the ceramic layer raw material and the foamed ceramic layer raw material to be ≤3%wt, the bonding degree of the plate is better, and the flatness is higher.

[0153] In Comparative Example 3, the slurry fineness and the water content of the ceramic layer powder are adjusted, and although the surface flatness is slightly reduced after firing, the sintering degree of the ceramic layer is not enough, there are dense pinholes, and a small amount of delamination and cracking (about 4%) occurs after being taken out of the kiln. The surface flatness of the foamed ceramic plate in Comparative Example 4 is good after firing, and there is no delamination and cracking phenomenon, but since the process parameters of the foamed ceramic layer powder are adjusted, the slurry fineness is enlarged, which leads to a high firing temperature, and the product density is 40-80kg / m 3 after firing at 1160℃, which is not completely sintered, and is not conducive to long-distance transportation, and the comprehensive performance is poor. In summary, when the process parameters of the ceramic powder are: slurry fineness 0.8-1.0%, slurry water content ≤35% by weight, powder water content 5%-5.5%, the process parameters of the foamed ceramic powder are: slurry fineness 0.8-1.0%, slurry water content ≤35% by weight, green strength higher than 1.3Mpa, powder water content 5.5-6.0%, bulk density 0.87-0.88g / ml, and the powder particle size of 20 mesh or more and 100 mesh or less is ≤1.5%, the fired product has higher flatness, no cracking and delamination, moderate foamed layer density, and better comprehensive performance, so that the thickness stability of the finished product is higher.

[0154] Example 6

[0155] The same parameters as in Example 3 are adopted, the only difference is that the foamed ceramic layer comprises a first foamed layer and a second foamed layer, and the raw material components of the first foamed layer and the second foamed layer are shown in the following table in mass fraction:

[0156]

[0157] The preparation process of Example 6 comprises the following steps:

[0158] (1) According to the above mass fraction, the ceramic layer raw materials are prepared into ceramic powder, and the process parameters of the ceramic powder are: slurry fineness 0.8%, slurry moisture content 35% by weight, and powder moisture content 5%; the ceramic powder is spread in the refractory kiln with a thickness of 15 mm, and then scraped flat;

[0159] (2) According to the above mass fraction, the first foamed layer raw materials and the second foamed layer raw materials are respectively prepared into first foamed powder and second foamed powder, and the process parameters of the first foamed powder and the second foamed powder are: slurry fineness 0.8%, slurry moisture content 35% by weight, powder moisture content 5.5%, bulk density 0.87 g / ml, and powder particles of more than 20 mesh and less than 100 mesh are ≤1.5% respectively, and the green strength is higher than 1.3 Mpa; first, the first foamed powder is spread on the ceramic layer with a thickness of 60 mm, and then the second foamed powder is spread on the first foamed layer after scraping flat with a thickness of 4 mm, and then scraped flat;

[0160] (3) Send into the kiln for firing, the firing temperature is 1160℃, the firing period is 13.5h, after cooling out of the kiln, remove the refractory kiln, and obtain the foamed ceramic plate;

[0161] (4) After cooling for 24h, cut the foamed ceramic plate into three equal parts along the side surface where the boundary line of the three layers is located, polish and grind the ceramic layer, and obtain three kinds of ceramic plates.

[0162] As shown in Figure 1 , the foamed ceramic plate prepared in Example 6 has a three-layer structure, which is a second foamed layer 1, a first foamed layer 2 and a ceramic layer 3, and the combination between each layer is stable, and the straightness of the layer boundary is good. As shown in Figure 2 a, after cutting along the cutting lines A and B, three kinds of ceramic plates can be obtained, as shown in Figure 2 b, which are ceramic plate material I combined by the first foamed layer 2 and the second foamed layer 1, ceramic plate material II only having the first foamed layer, and ceramic plate material III combined by the ceramic layer 3 and the first foamed layer 2. Among them, the second foamed layer 1 and the ceramic layer 3 are respectively used as the surface decoration layer of the ceramic plate material I and the ceramic plate material III, the second foamed layer can improve the decoration by adding known colorants, and the hardness can be improved by adjusting the density after sintering.

[0163] Example 7

[0164] The same parameters and preparation steps as in Example 1 are used, with the exception that between step (2) and step (3) a step of spreading a low-temperature powder prepared from raw materials in the following mass percentages (in %) is added to the foamed ceramic layer.

[0165]

[0166] The anti-fouling performance of the surface of the product after firing is tested. The sludge and dust are covered on the foamed ceramic surface layer, and can be washed clean with clean water. Due to the characteristics of the foamed ceramic itself, there are holes on the rough surface, so the anti-fouling effect of the product is poor during use. The spreading of some low-temperature substances on the foamed ceramic layer in Example 7 can effectively improve the anti-fouling performance of the surface of the foamed ceramic layer.

[0167] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made according to the content of the present application, or direct / indirect application in other related technical fields within the inventive concept of the present application is included in the patent protection scope of the present application.

Claims

1. A process for producing foamed ceramic panels, characterized in that, Includes the following steps: (1) Laying ceramic layer: Spread ceramic powder with a thickness of ≥5mm inside the refractory kiln furniture and scrape it level; (2) Laying the foamed ceramic layer: Sprinkle the foamed ceramic powder onto the ceramic layer and smooth it out; (3) The ceramic board is fired in a kiln, cooled and removed from the kiln, and the refractory kiln furniture is removed to obtain the foamed ceramic board. (4) The foamed ceramic board obtained in step (3) is ground and / or cut according to the required shape to obtain the finished product; The linear thermal expansion coefficient α1 of the raw material for the ceramic layer mentioned in step (1) meets the following requirements: 30-200℃:6.0×10 -6 K -1 ≤ α1≤ 6.6×10 -6 K -1 ;30-600℃:7.0 ×10 -6 K -1 ≤ α1≤ 7.5×10 -6 K -1 ; The linear thermal expansion coefficient α2 of the raw material for the foamed ceramic layer in step (2) meets the following requirements: 30-200℃:5.7×10 -6 K -1 ≤ α2≤ 6.4×10 -6 K -1 ;30-600℃:6.7×10 -6 K -1 ≤ α2≤ 7.6×10 -6 K -1 ; The difference in the linear thermal expansion coefficients between the raw materials of the ceramic layer and the raw materials of the foamed ceramic layer at 30-200℃ and 30-600℃ is ≤0.7×10⁻⁶. -6 K -1 ; The loss on ignition of the raw materials for the ceramic layer and the raw materials for the foamed ceramic layer is ≤3%wt; The powder for the ceramic layer is obtained by ball milling and spray granulation. The ball milling process parameters are: slurry fineness 0.8-1.0%, slurry moisture content ≤35% by weight; The moisture content of the powder in the ceramic layer is 5-5.5%, and the thickness of the ceramic layer fabric is 10-25 mm. The powder for the foamed ceramic layer is obtained by ball milling and spray granulation. The ball milling process parameters are: slurry fineness 0.8-1.0%, slurry moisture content ≤35% by weight; The green strength of the foamed ceramic layer powder is higher than 1.3 MPa, the powder moisture content is 5.5-6.0%, the bulk density is 0.87-0.88 g / ml, and the powder particles with a mesh size of 20 or larger and 100 or smaller are ≤1.5% respectively. The thickness of the foamed ceramic layer is 25-75 mm.

2. The foamed ceramic board production process as described in claim 1, characterized in that, The linear thermal expansion coefficient α1 of the raw material for the ceramic layer meets the following requirements: 30-100℃:5.9×10 -6 K -1 ≤ α1≤ 6.6×10 -6 K -1 ;30-200℃:6.0×10 -6 K -1 ≤ α1≤ 6.6×10 -6 K -1 ;30-300℃:6.3×10 -6 K -1 ≤ α1≤ 6.8×10 -6 K -1 ;30-400℃:6.5×10 -6 K -1 ≤ α1≤6.9×10 -6 K -1 ;30-500℃:6.7×10 -6 K -1 ≤ α1≤ 7.1×10 -6 K -1 ;30-600℃:7.0×10 -6 K -1 ≤α1≤ 7.5×10 -6 K -1 ;30-700℃:7.0 ×10 -6 K -1 ≤ α1≤ 7.6×10 -6 K -1 ;30-800℃:8.2×10 -6 K -1 ≤ α1≤ 8.5×10 -6 K -1 ; The linear thermal expansion coefficient α2 of the raw material of the foamed ceramic layer meets the following requirements: 30-100℃:5.5×10 -6 K -1 ≤ α2≤ 6.2×10 -6 K -1 ;30-200℃:5.7×10 -6 K -1 ≤ α2≤ 6.4×10 -6 K -1 ;30-300℃:6.0×10 -6 K -1 ≤ α2≤ 6.7×10 -6 K -1 ;30-400℃:6.2×10 -6 K -1 ≤ α2≤6.9×10 -6 K -1 ;30-500℃:6.6×10 -6 K -1 ≤ α2≤ 7.2×10 -6 K -1 ;30-600℃:6.7×10 -6 K -1 ≤α2≤ 7.6×10 -6 K -1 ;30-700℃:6.9×10 -6 K -1 ≤ α2≤ 7.6×10 -6 K -1 ;30-800℃:7.1×10 -6 K -1 ≤ α2≤ 8.4×10 -6 K -1 。 3. The foamed ceramic board production process as described in claim 1, characterized in that, The raw material components of the ceramic layer, by mass parts, include: 10 parts of 9033 zircon white frit, 5 parts of calcined talc, 20 parts of microcrystalline frit, 35 parts of potassium sodium quartz powder, 15 parts of potassium feldspar, 10 parts of sodium feldspar, 5 parts of clay, 0.25 parts of sodium tripolyphosphate, and 0.15 parts of sodium carboxymethyl cellulose. The raw material components of the foamed ceramic layer, by mass parts, include: 4 parts of 9033 zircon white fused agglomerate, 15 parts of pressed mud, 20 parts of foamed ceramic waste, 4 parts of magnesia clay, 32 parts of river sand tailings, 5 parts of Shirong tailings, 20 parts of construction slag, 0.25 parts of green body reinforcing agent, and 0.3 parts of green silicon. The chemical composition of the Shirong tailings, by mass percentage, includes: SiO2: 63.47%, Al2O3: 3.41%, Fe2O3: 0.43%, TiO2: 0.13%, CaO: 18.18%, MgO: 1.76%, K2O: 0.76%, Na2O: 7.45%, LOI: 4.41%.

4. The foamed ceramic board production process as described in claim 1, characterized in that, The cutting process described in step (4) includes the step of splitting the foamed ceramic plate. The splitting step is based on the boundary line between the sintered ceramic layer and the foamed ceramic layer, and the split line is located on one side of the foamed ceramic layer.

5. The foamed ceramic board production process as described in claim 1, characterized in that, The foamed ceramic layer includes at least two types of foamed layers, namely a first foamed layer and a second foamed layer, which exhibit different decorative effects after firing. The process of spreading the material involves first spreading the first foamed layer powder, smoothing it out, and then spreading the second foamed layer powder.

6. The foamed ceramic board production process as described in claim 1, characterized in that, Between steps (2) and (3), there is also a step of spreading low-temperature raw materials that form a protective layer after firing in step (3) onto the foamed ceramic layer. The components of the low-temperature raw materials, in terms of the mass percentage of oxides, include: SiO2: 54.35-68.96%, Al2O3: 8.45-14.34%, Fe2O3: 0.2-0.6%, TiO2: 0.04-0.2%, CaO: 5.04-18.4%, MgO: 1.1-3.1%, K2O: 0.5-5.8%, Na2O: 3.5-9%, BaO: 0.02-3.01%, ZnO: 0.05-8%, LOI: 0.2-3%.

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