A secondary sintered microcrystalline ceramic glaze and preparation method thereof, and microcrystalline ceramic glaze brick

Abstract

The present invention provides a secondary sintered microcrystalline ceramic glaze, a preparation method thereof, and a microcrystalline ceramic glaze brick. The method comprises: mixing ingredients according to a predetermined raw material formula and then ball milling to obtain a glaze powder; calcining the glaze powder to obtain a sintered material; mixing ingredients according to a predetermined microcrystalline ceramic glaze formula and grinding them into a glaze slurry, wherein the microcrystalline ceramic glaze formula includes the sintered material; applying the glaze slurry to a brick blank and then secondary calcining to obtain a microcrystalline ceramic glaze. The microcrystals in the microcrystalline ceramic glaze prepared by the present invention are formed during the first sintering and do not completely melt during the second sintering, eliminating the need for a melting followed by crystallization process. Therefore, the microcrystalline glaze is minimally affected by the kiln temperature, has a wide firing range, and is beneficial to production stability.

Description

Technical Field

[0001] The present invention relates to the technical field of building ceramics, and in particular to a secondary sintered microcrystalline ceramic glaze and a preparation method thereof, and a microcrystalline ceramic glaze brick. Background Art

[0002] The microcrystalline ceramic glaze used for ceramic tiles is prepared according to the formula, with water and additives added, and ground into a glaze slurry below 325 mesh. It is then glazed and fired, which can also be called the powder sintering method. There are usually two formula structures. One is to use a full raw material formula. This formula requires a higher kiln temperature and a longer high-fire insulation time than the current ceramic tile industry to produce a smooth glaze surface and low gloss effect for the microcrystalline ceramic glaze. This does not meet the needs of low-carbon production and is generally not adopted. The second is to use a semi-raw material formula. The current ceramic industry produces microcrystalline ceramic glaze products using this formula structure, that is, using kaolin, feldspar, quartz, calcite, burned talc, barium carbonate, strontium carbonate, etc., plus 1 to 3 types of glass powder (commonly known as frit in the ceramic industry) and firing.

[0003] However, during the production process of microcrystalline ceramic glaze with a semi-raw material structure, the firing range of the glaze is narrow. When the kiln temperature fluctuates slightly, the gloss, transparency, and surface roughness of the glaze surface are very likely to change. Therefore, the production stability is poor.

[0004] Therefore, the existing technology has defects and needs to be improved and developed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a secondary sintered microcrystalline ceramic glaze and its preparation method, and microcrystalline ceramic glaze bricks in response to the above-mentioned defects of the prior art, aiming to solve the problems of narrow firing range and poor production stability of microcrystalline ceramic glaze with semi-raw material structure in the prior art during production.

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0007] A first embodiment of the present application provides a method for preparing a twice-sintered microcrystalline ceramic glaze, wherein the method comprises:

[0008] The raw materials are mixed according to a predetermined formula and then ball-milled to obtain glaze powder;

[0009] calcining the glaze powder to obtain a sintered material;

[0010] Mixing ingredients according to a predetermined microcrystalline ceramic glaze formula and grinding them into a glaze slurry, wherein the microcrystalline ceramic glaze formula includes the sintering material;

[0011] The glaze slurry is applied to a green brick and then secondary calcined to obtain a microcrystalline ceramic glaze.

[0012] In one embodiment of the present application, the raw material formula includes a first raw material formula and a second raw material formula, and the first raw material formula includes, by weight percentage:

[0013] Kaolin 10-15%, potassium feldspar 18-25%, frit 5-10%, barium carbonate 10-13%, calcite 18-30%, zinc oxide 4-8%, quartz 18-25%;

[0014] The second raw material formula comprises, by weight percentage:

[0015] Potassium feldspar 45-55%, frit 6-10%, barium carbonate 10-18%, calcite 20-25%, zinc oxide 3-6%, quartz 12-18%.

[0016] In one embodiment of the present application, the chemical components of the frit, calculated by weight percentage, include:

[0017] Loss on ignition 0.3-1.2%, SiO2 50-60%, Al2O3 8-12%, Fe2O3 0.1-0.5%, TiO20.08-0.2%, CaO 16-20%, MgO 5-8%, K2O 3.5-5%, Na2O 2-3%, ZnO 0.3-0.6%, B2O3 0.1-0.3%, BaO 0.6-1.5%.

[0018] In one embodiment of the present application, the process of preparing the raw materials according to a predetermined formula and then ball milling the raw materials to obtain the glaze powder comprises:

[0019] After mixing the ingredients according to the predetermined raw material formula, sodium carboxymethyl cellulose, sodium tripolyphosphate and water are added and wet ball milled to a fineness of 0.1-0.3% on a 325 mesh sieve, and spray dried to obtain a glaze powder;

[0020] Alternatively, the raw materials are mixed according to a predetermined formula and then conveyed to a Raymond mill for fine grinding to a fineness of 0.1-0.3% with a 325-mesh sieve residue to obtain a glaze powder.

[0021] In one embodiment of the present application, calcining the glaze powder material to obtain a sintered material comprises:

[0022] The glaze powder is calcined at a temperature of 1000-1150° C. to obtain a sintered material.

[0023] In one embodiment of the present application, the microcrystalline ceramic glaze formula comprises, by weight percentage:

[0024] Kaolin 8-12%, sintering material 60-90%, ultrafine corundum powder 0-5%, ultrafine alumina powder 0-5%, calcined kaolin 0-8%, potassium feldspar 0-30%, sodium feldspar 0-20%, wollastonite 0-5%, burned talc 0-8%, dolomite 0-10%, calcite 0-12%, barium carbonate 0-8%, strontium carbonate 0-5%, zinc oxide 0-8%.

[0025] In one embodiment of the present application, the glaze slurry is applied to a green brick and then subjected to secondary calcination to obtain a microcrystalline ceramic glaze, comprising:

[0026] After the glaze slurry is applied to the brick, secondary calcination is performed at a temperature of 1140-1230° C. to obtain a microcrystalline ceramic glaze.

[0027] In one embodiment of the present application, the glaze slurry is applied to a green brick and then subjected to secondary calcination to obtain a microcrystalline ceramic glaze, comprising:

[0028] If the glaze slurry is prepared from the sintered material prepared from the first raw material formula, the glaze slurry is applied to the brick and then secondary calcined at a temperature of 1190° C. to 1230° C. to obtain a microcrystalline ceramic glaze;

[0029] If the glaze slurry is prepared from the sintered material prepared from the second raw material formula, the glaze slurry is applied to the brick and then secondary calcined at a temperature of 1140° C. to 1170° C. to obtain a microcrystalline ceramic glaze.

[0030] A second aspect of the present application provides a microcrystalline ceramic glaze, wherein the microcrystalline ceramic glaze is prepared based on the preparation method of the secondary sintered microcrystalline ceramic glaze as described above.

[0031] A third embodiment of the present application provides a microcrystalline ceramic glazed tile, wherein the microcrystalline ceramic glaze as described above is applied on the microcrystalline ceramic glaze tile.

[0032] The present invention discloses a secondary sintered microcrystalline ceramic glaze, a preparation method thereof, and a microcrystalline ceramic glaze brick. The method comprises: mixing ingredients according to a predetermined raw material formula and then ball milling to obtain a glaze powder; calcining the glaze powder to obtain a sintered material; mixing ingredients according to a predetermined microcrystalline ceramic glaze formula and grinding them into a glaze slurry, wherein the microcrystalline ceramic glaze formula includes the sintered material; applying the glaze slurry to a brick blank and then secondary calcining to obtain a microcrystalline ceramic glaze. The microcrystals in the microcrystalline ceramic glaze prepared by the present invention are formed during the first sintering and do not completely melt during the second sintering, eliminating the need for a melting followed by crystallization process. Therefore, the microcrystalline glaze is minimally affected by the kiln temperature, has a wide firing range, and is beneficial to production stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1The present invention is a flowchart of a preferred embodiment of a method for preparing a secondary sintered microcrystalline ceramic glaze.

[0034] Figure 2 It is the diffraction pattern of the sintered material prepared by the first raw material formula in the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear and distinct, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Traditional ceramic crystalline glazes are categorized by the size of their crystals into macrocrystalline, fine-crystalline, and microcrystalline ceramic glazes. Zinc and titanium crystalline glazes, with their large crystals, are macrocrystalline glazes. Glazes like tea-dust and gold aventurine have a visible crystal effect, with the crystals visible under a 10x magnifying glass. These glazes are fine-crystalline. Microcrystalline ceramic glazes, on the other hand, are invisible to the naked eye and require special treatment for observation under a microscope.

[0037] The crystals in crystalline glazes are precipitated from the melt. There are two technical approaches: one involves melting the formulated material at high temperature, shaping it after cooling or before cooling, and then subjecting it to low-temperature heat treatment to precipitate the crystals. This is the manufacturing process for micro-glass. The other involves applying the formulated material to the surface of a formed body, melting it at high temperature during firing, and crystallizing it during cooling. Famous traditional ceramic glazes such as zinc crystal glaze, iron red glaze, tea-leaf glaze, and gold dust glaze all fall into this category.

[0038] There are two existing production processes for glass-ceramics used in architectural decoration: sintering and melting. Both involve mixing ingredients according to a recipe, melting the glass in a glass melting tank, and then crystallizing it. The process features are as follows:

[0039] Table 1 Classification of glass-ceramic manufacturing processes

[0040]

[0041] In the sintering production of microcrystalline glass, the sintering method can be divided into glass particle sintering method and glass powder sintering method. However, in the field of preparing microcrystalline glass for architectural decoration, the glass powder sintering method has not been actually applied. In the microcrystalline glass industry, the sintering method refers to the glass particle sintering method.

[0042] Table 2 Chemical composition requirements of mother glass for different production processes of glass-ceramics

[0043]

[0044] Among them, the specific basic chemical composition should be determined according to the selected mother glass system.

[0045] However, the microcrystalline preparation process of microcrystalline glass is not suitable for the glaze of ceramic tiles.

[0046] The microcrystalline ceramic glaze used for ceramic tiles is prepared according to the formula, with water and additives added, and ground into a glaze slurry below 325 mesh. It is then glazed and fired, which can also be called the powder sintering method. There are usually two formula structures. One is to use a full raw material formula. This formula requires a higher kiln temperature and a longer high-fire insulation time than the current ceramic tile industry to produce a smooth glaze surface and low gloss effect for the microcrystalline ceramic glaze. This does not meet the needs of low-carbon production and is generally not adopted. The second is to use a semi-raw material formula. The current ceramic industry produces microcrystalline ceramic glaze products using this formula structure, that is, using kaolin, feldspar, quartz, calcite, burned talc, barium carbonate, strontium carbonate, etc., plus 1 to 3 types of glass powder (commonly known as frit in the ceramic industry) and firing.

[0047] There are many problems in the production process of microcrystalline ceramic glaze with semi-raw material structure:

[0048] First, the glaze has a narrow firing range. Kiln temperature fluctuations of less than 5°C can cause variations in glaze texture. During the production process, even slight fluctuations in kiln temperature can easily cause variations in glaze gloss, transparency, and surface roughness. This is particularly true for the two popular microcrystalline ceramic glazes with gloss levels of 12±2° and 18±2°. Generally, increasing kiln temperature increases glaze gloss while maintaining or increasing transparency; decreasing kiln temperature reduces glaze gloss and transparency. This formulation quirk presents a significant obstacle to consistent product quality.

[0049] Second, the glaze formula has poor adaptability and places high demands on the kiln. When producing microcrystalline ceramic glaze products using semi-raw glaze, frit selection is crucial due to varying kiln firing conditions, requiring a kiln-specific formula. Poor frit coordination often results in a glaze that is smooth while remaining pinhole-free. While this formula system achieves a smooth glaze, defects like pinholes and bubbles are more likely to appear. When the formula is adjusted to eliminate pinholes, the glaze either wrinkles and becomes difficult to smooth, or the glaze is smooth but glossy, failing to achieve a low gloss finish.

[0050] Third, formula adjustment is difficult to master, often disrupting production cycles due to substandard glaze texture. Semi-raw microcrystalline ceramic glaze formulas melt at high temperatures, and crystals precipitate on the glaze surface during supercooling. The thermal analysis of this formula shows distinct endothermic peaks (the glaze absorbs a large amount of heat before melting) and exothermic peaks (the melt releases heat during supercooling, precipitating crystals).

[0051] Therefore, the production of microcrystalline ceramic glaze tiles under medium-temperature, fast-firing conditions presents numerous challenges. Primarily, the precipitation of microcrystals from the melt in the glaze requires slow firing conditions. For semi-cooked materials, regardless of the frit formulation, rapid-firing conditions present significant challenges in achieving crystallization from the melt. Kiln temperature fluctuations cause variations in the amount of crystallization, which in turn leads to changes in the glaze's diffuse reflectance and ultimately, gloss, resulting in lengthy formulation adjustments.

[0052] The present invention provides a secondary sintered microcrystalline ceramic glaze, in which microcrystals synthesized by a solid-phase reaction method are introduced into the glaze. When producing the microcrystalline ceramic glaze, the initial melting temperature of the glaze can be greatly increased, the firing temperature range of the microcrystalline ceramic glaze can be widened, and pinhole bubbles in the glaze can be eliminated, thereby reducing the difficulty of formula debugging and product production, and improving the product quality rate. The problem that the glaze effect is greatly affected by the kiln temperature and the thickness of the glaze layer, the glaze surface has pinhole rashes, the adaptability of the glaze formula is poor, and the firing range is narrow is solved. Under medium-temperature fast firing conditions, the glaze gloss is reduced to below 10 degrees and the surface roughness is reduced to 0.6 microns.

[0053] The first aspect of the present application provides a method for preparing a secondary sintered microcrystalline ceramic glaze, such as Figure 1 As shown, the preparation method of the secondary sintered microcrystalline ceramic glaze includes:

[0054] Step S100: mixing raw materials according to a predetermined raw material formula and then ball milling to obtain glaze powder.

[0055] In the embodiment of the present application, the raw material formula includes a first raw material formula and a second raw material formula, and the first raw material formula includes, by weight percentage:

[0056] 10-15% kaolin, 18-25% potassium feldspar, 5-10% frit, 10-13% barium carbonate, 18-30% calcite, 4-8% zinc oxide, 18-25% quartz; wherein the sum of the weight percentages of the various components is 100%.

[0057] The second raw material formula comprises, by weight percentage:

[0058] Potash feldspar 45-55%, frit 6-10%, barium carbonate 10-18%, calcite 20-25%, zinc oxide 3-6%, quartz 12-18%; wherein the sum of the weight percentages of the various components is 100%.

[0059] Specifically, the raw material formula of the embodiment of the present application includes two types to adapt to different kiln temperatures during secondary calcination. In the sintered material prepared by the first raw material formula, there will be two types of crystals synthesized by the solid-phase reaction method. One is to generate a large number of barium cryolite crystals, which serve as the main crystal phase in the microcrystalline ceramic glaze. A large amount of them in the glaze can make the glaze matte; the other is to generate zinc feldspar and wollastonite. When finely ground corundum (α-Al2O3) is introduced into the formula and reacts with it in the solid phase, microcrystals such as barium cryolite and calcium feldspar can be generated, making the glaze matte. The phase analysis results are shown in Table 3. The diffraction pattern of the sintered material prepared by the first raw material formula is shown in Table 3. Figure 2 shown.

[0060] Table 3 Phase analysis test results

[0061]

[0062] The raw material formula of the present invention is simple and easy to master. In this formulation, the sintering material accounts for 85±5wt% and kaolin accounts for 8-12wt%. Fired in a common ceramic tile kiln, the glaze has a gloss of 20±10 degrees, a smooth and delicate glaze surface, and a surface roughness of less than 1.0 micron.

[0063] If the glaze is too glossy, you can reduce it by adding a small amount of ultrafine corundum, ultrafine alumina powder, or calcined kaolin. The order of gloss reduction strength of these three ingredients is: ultrafine corundum ≈ ultrafine alumina powder > > calcined kaolin. The amount of each ingredient can be fine-tuned depending on the specific situation.

[0064] If the glaze's gloss is too low, small amounts of potassium feldspar, albite, wollastonite, or calcined talc can be added to improve gloss. The order of gloss enhancement for these four ingredients is: wollastonite > albite > potassium feldspar > calcined talc. The amount of each ingredient added can be fine-tuned depending on the specific situation. The addition of these two ingredients in small amounts will not significantly affect the surface roughness of the glaze.

[0065] In this embodiment, the first raw material formula specifically includes, by weight percentage, kaolin 14%, potassium feldspar 24%, frit 6%, barium carbonate 12%, calcite 20%, zinc oxide 5%, and quartz 19%. The second raw material formula specifically includes, by weight percentage, potassium feldspar 45%, frit 6%, barium carbonate 11%, calcite 21%, zinc oxide 5%, and quartz 12%.

[0066] The embodiments of this application simplify the glaze formulation for microcrystalline ceramic tiles with a gloss of less than 20 degrees, resulting in low surface roughness, no defects such as pinholes or bubbles, wide adaptability to kiln firing temperatures, and low requirements for glaze layer thickness. This is of great significance for improving the quality and maintaining the stability of this type of ceramic tile products.

[0067] In one embodiment of the present application, the chemical components of the frit, calculated by weight percentage, include:

[0068] Loss on ignition 0.3-1.2%, SiO2 50-60%, Al2O3 8-12%, Fe2O3 0.1-0.5%, TiO2 0.08-0.2%, CaO 16-20%, MgO 5-8%, K2O 3.5-5%, Na2O 2-3%, ZnO 0.3-0.6%, B2O3 0.1-0.3%, BaO 0.6-1.5%; wherein the sum of the weight percentages of each component is 100%.

[0069] Specifically, the chemical composition analysis of the frit is: loss on ignition 1.02%, SiO2 52.76%, Al2O3 11.93%, Fe2O3 0.11%, TiO2 0.2%, CaO 18.46%, MgO 6.82%, K2O 4.19%, Na2O 2.05%, ZnO 0.6%, B2O3 0.18%, and BaO 1.31%.

[0070] In an embodiment of the present application, step S100 specifically includes: after mixing the ingredients according to a predetermined raw material formula, adding sodium carboxymethyl cellulose, sodium tripolyphosphate and water for wet ball milling, grinding to a fineness of 0.1 to 0.3% with a 325-mesh sieve residue, and spray drying to obtain a glaze powder; or, after mixing the ingredients according to a predetermined raw material formula, conveying them to a Raymond mill for fine grinding to a fineness of 0.1 to 0.3% with a 325-mesh sieve residue, to obtain a glaze powder.

[0071] Specifically, the embodiment of the present application gives priority to dry ball milling, and wet ball milling is the second choice. In wet ball milling, 0.1%-0.3% of sodium carboxymethyl cellulose (CMC) and 0.3%-0.6% of sodium tripolyphosphate are added, and 40%-46% of water are added, and the mixture is ground to a fineness of 0.1-0.3% on a 325-mesh sieve, and spray-dried to obtain a glaze powder to be fired. Wet ball milling is beneficial to improving the convenience and efficiency of iron removal in the glaze slurry during the processing. In dry ball milling, no additives are added, and the mixture is transported to a Raymond mill for fine grinding to a fineness of 0.1-0.3% on a 325-mesh sieve, and then fired. The energy consumption cost of dry ball milling is relatively low.

[0072] like Figure 1 As shown, the preparation method of the secondary sintered microcrystalline ceramic glaze further includes:

[0073] Step S200: calcining the glaze powder to obtain a sintered material.

[0074] Specifically, the embodiment of the present application is a loose sintering of bulk materials. The strength of the particles after sintering is not high and it is very easy to finely grind, so there is no need for crushing and coarse grinding.

[0075] In the embodiment of the present application, the step S200 specifically includes: calcining the glaze powder material at a temperature of 1000-1150° C. to obtain a sintered material.

[0076] Specifically, the finely ground glaze powder is calcined at a temperature of 1000-1150°C and kept warm on high heat for 1 hour. The sintering degree of the sintered material has a great influence on its use in the glaze. If the sintering degree of the sintered material is high, the initial melting point of the sintered material is low, and the microcrystalline ceramic glaze is prone to premature closure of pores at high temperatures, resulting in defects such as pinholes and prickly heat on the glaze surface. If the sintering degree of the sintered material is low, the carbonate cannot fully react with silicon, aluminum, etc., and calcium, barium and other ions dissolve in water, resulting in a strong thixotropy of the glaze slurry and a large flow rate, which does not meet the requirements of the glazing process. Therefore, the embodiment of the present application also controls the sintering degree of the sintered material.

[0077] To measure the degree of sintering, the material to be fired can be adjusted to a moisture content of 6-8%, pressed into a cake at 35 MPa, and fired simultaneously with the material to be fired. It is then calcined at 1000-1150°C and used for later use. The water absorption of the cake out of the kiln should be between 20% and 25%, which can largely ensure the material's high initial melting point, while ensuring that its addition to the glaze does not cause strong thixotropy and high flow rate, making it easy to apply the glaze.

[0078] In the microcrystalline ceramic glaze of the embodiments of the present application, the carbonates are fully reacted after calcination at 1000-1150°C, the silicon and aluminum content in the sintered material is not very high, the microcrystalline ceramic glaze has a high initial melting point during the firing process and a low viscosity at high temperature, so the use of the sintered material in the glaze will not cause the glaze surface to close prematurely, and the gas in the body can be discharged smoothly; since the silicon and aluminum content in the formula is not high, the glaze has a low viscosity at high temperature and can easily fill the exhaust holes, thereby eliminating glaze defects such as pinholes and prickly heat.

[0079] like Figure 1 As shown, the preparation method of the secondary sintered microcrystalline ceramic glaze further includes:

[0080] Step S300: Mix ingredients according to a predetermined microcrystalline ceramic glaze formula and grind them into a glaze slurry, wherein the microcrystalline ceramic glaze formula includes the sintering material.

[0081] Specifically, the microcrystalline ceramic glaze firing process includes: batching → wet ball milling → testing fineness and flow rate → adjusting flow rate → discharging slurry → transporting to the glaze line for glazing → firing → obtaining microcrystalline ceramic glaze ceramic tile products. The glaze slurry has a fineness of 0.2-0.4% on a 325-mesh sieve, and the slurry flow rate is approximately 35 seconds.

[0082] In the embodiment of the present application, the formula of the microcrystalline ceramic glaze includes, by weight percentage: 8-12% kaolin, 60-90% sintering material, 0-5% ultrafine corundum powder, 0-5% ultrafine alumina powder, 0-8% calcined kaolin, 0-30% potassium feldspar, 0-20% sodium feldspar, 0-5% wollastonite, 0-8% burned talc, 0-10% dolomite, 0-12% calcite, 0-8% barium carbonate, 0-5% strontium carbonate, and 0-8% zinc oxide; wherein the sum of the weight percentages of each component is 100%.

[0083] Specifically, the above sintered materials are mixed with kaolin, calcined kaolin, potassium feldspar, sodium feldspar, corundum (or alumina), wollastonite, burned talc, etc. according to a formula and finely ground into glaze slurry, which is then glazed on inkjet-printed ceramic tiles and fired at 1150-1230°C to produce microcrystalline ceramic glazed tiles.

[0084] like Figure 1 As shown, the preparation method of the secondary sintered microcrystalline ceramic glaze further includes:

[0085] Step S400: applying the glaze slurry to the brick and then performing secondary calcination to obtain a microcrystalline ceramic glaze.

[0086] Specifically, the microcrystalline ceramic glaze in the embodiment of the present application is a microcrystalline ceramic glaze covering the surface of the brick, with the glaze gloss adjustable between 5 and 20 degrees and the glaze surface roughness below 1.0 micron, and the main crystal phase of its microcrystals is barium adularia.

[0087] In the embodiment of the present application, the step S400 specifically includes: applying the glaze slurry to the brick, and then performing secondary calcination at a temperature of 1140-1230° C. to obtain a microcrystalline ceramic glaze.

[0088] Specifically, the glaze slurry bell jar is poured onto the brick blank, and is put into the kiln for firing along with the brick blank. After being fired at 1140-1230° C., a smooth and low-gloss microcrystalline ceramic glaze is formed.

[0089] In a specific embodiment of the present application, step S400 specifically includes: if the glaze slurry is prepared from a sintered material prepared from a first raw material formula, then after the glaze slurry is applied to the brick blank, it is subjected to secondary calcination at a temperature of 1190°C-1230°C to obtain a microcrystalline ceramic glaze; if the glaze slurry is prepared from a sintered material prepared from a second raw material formula, then after the glaze slurry is applied to the brick blank, it is subjected to secondary calcination at a temperature of 1140°C-1170°C to obtain a microcrystalline ceramic glaze.

[0090] Specifically, the first and second raw material formulas are differentiated based on their suitability for different kiln temperatures. For high kiln temperatures, the first raw material formula is used, with an applicable range of 1190°C-1230°C. For low kiln temperatures, the second raw material formula is used, with an applicable range of 1140°C-1170°C. A mixture of the two is also acceptable.

[0091] The microcrystalline ceramic glaze obtained in the embodiment of the present application has a wide firing range and wider adaptability. The microcrystals in the microcrystalline ceramic glaze are formed during the first sintering and will not be completely melted during the secondary sintering (the crystals in the glaze, unless they reach their melting temperature or are melted into glass by the low-temperature glass phase, still exist in the form of crystals). Therefore, there are a large number of tiny crystals in the glaze, making the glaze matte. During the secondary sintering process of the microcrystalline ceramic glaze, from the thermal analysis diagram of the glaze, there is no obvious endothermic peak, only an exothermic peak. It does not need to go through the process of first melting and then crystallizing. Therefore, it is minimally affected by the kiln temperature, has a wide firing range, and is conducive to production stability.

[0092] The microcrystalline ceramic glaze of the embodiment of the present application has a wide firing range, which is mainly reflected in two aspects.

[0093] First, it can adapt to a wider range of kiln firing temperatures.

[0094] Table 4 Firing effect of the first raw material formula in different kilns

[0095]

[0096] The microcrystalline ceramic glazes in the examples of this application, fired in kilns with a temperature difference of 30°C, achieved a uniformly smooth and fine glaze surface, with a maximum gloss difference of only 2 degrees and a surface roughness of less than 1.0 micron. In experiments with microcrystalline ceramic glazes, inkjet-printed in-glaze colors exhibited excellent color development and translucency, enhancing production stability.

[0097] Second, it can adapt to different glaze layer thicknesses.

[0098] As is well known, the effect of crystallized glazes is greatly affected by the thickness of the glaze layer. However, the thickness of the glaze layer of the microcrystalline ceramic glaze of the present invention has minimal effect on the crystallization effect and, consequently, the glaze gloss, as shown in the table below.

[0099] Table 5 Glaze effects of different thicknesses of scraped printing of the first raw material formula fired on the J1 line

[0100]

[0101] Table 6 Glaze effect of different thicknesses of scraped printing of the first raw material formula fired on Q6 line

[0102]

[0103] Table 7 Glaze effect of different thicknesses of scraped printing of the first raw material formula fired on Q5 line

[0104]

[0105] The embodiments of the present application achieve the following effects:

[0106] First, the microcrystalline ceramic glaze prepared in the embodiment of the present application has a glaze gloss as low as below 10 degrees, a surface roughness as low as 0.6 microns, and no pinholes or prickly heat on the glaze surface. The glaze effect is less affected by the kiln temperature and the thickness of the glaze layer. The glaze formula has good adaptability and a wide firing range.

[0107] Second, the microcrystalline ceramic glaze prepared in the embodiment of the present application has a simple formula structure and wide adaptability, and is very easy for technicians to master and use.

[0108] Third, the sintering material of the embodiment of the present application has a low sintering temperature, which saves energy for society; the structure is loose after sintering, which saves processing costs.

[0109] Fourth, the embodiment of the present application replaces the high-temperature melting material (microcrystalline frit) with a low-temperature sintering material, thereby achieving the substitutability of the glaze formulation.

[0110] In a second aspect, the present application provides a microcrystalline ceramic glaze, which is prepared based on the preparation method of the secondary sintered microcrystalline ceramic glaze as described above.

[0111] A third aspect of the present application provides a microcrystalline ceramic glazed tile, wherein the microcrystalline ceramic glaze as described above is applied on the microcrystalline ceramic glaze tile.

[0112] The present invention provides a secondary sintered microcrystalline ceramic glaze, a preparation method thereof, and a microcrystalline ceramic glaze brick. The method comprises: mixing ingredients according to a predetermined raw material formula and then ball milling to obtain a glaze powder; calcining the glaze powder to obtain a sintered material; mixing ingredients according to a predetermined microcrystalline ceramic glaze formula and grinding them into a glaze slurry, wherein the microcrystalline ceramic glaze formula includes the sintered material; applying the glaze slurry to a brick blank and then secondary calcining to obtain a microcrystalline ceramic glaze. The microcrystals in the microcrystalline ceramic glaze prepared by the present invention are formed during the first sintering and do not completely melt during the second sintering, eliminating the need for a melting followed by crystallization process. Therefore, the microcrystalline glaze is minimally affected by the kiln temperature, has a wide firing range, and is beneficial to production stability.

[0113] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a secondary sintered microcrystalline ceramic glaze, characterized in that: The method comprises: The raw materials are mixed according to a predetermined formula and then ball-milled to obtain glaze powder; calcining the glaze powder to obtain a sintered material; Mixing ingredients according to a predetermined microcrystalline ceramic glaze formula and grinding them into a glaze slurry, wherein the microcrystalline ceramic glaze formula includes the sintering material; applying the glaze slurry to a green brick and then performing secondary calcination to obtain a microcrystalline ceramic glaze; The microcrystals in the microcrystalline ceramic glaze are formed when the glaze powder is calcined, and will not be completely melted during the secondary calcination; The raw material formula includes a first raw material formula and / or a second raw material formula, and the first raw material formula includes, by weight percentage: Kaolin 10-15%, potassium feldspar 18-25%, frit 5-10%, barium carbonate 10-13%, calcite 18-30%, zinc oxide 4-8%, quartz 18-25%; The second raw material formula comprises, by weight percentage: Potash feldspar 45-55%, frit 6-10%, barium carbonate 10-18%, calcite 20-25%, zinc oxide 3-6%, quartz 12-18%; the sum of the weight percentages of the components in the second raw material formula is 100%.

2. The method for preparing the secondary sintered microcrystalline ceramic glaze according to claim 1, characterized in that: The chemical components of the frit are calculated by weight percentage and include: Loss on ignition 0.3-1.2%, SiO2 50-60%, Al2O3 8-12%, Fe2O3 0.1-0.5%, TiO2 0.08-0.2%, CaO16-20%, MgO 5-8%, K2O 3.5-5%, Na2O 2-3%, ZnO 0.3-0.6%, B2O3 0.1-0.3%, BaO 0.6-1.5%.

3. The method for preparing the secondary sintered microcrystalline ceramic glaze according to claim 1, characterized in that: The glaze powder is obtained by mixing the raw materials according to a predetermined formula and then ball milling the raw materials to obtain the glaze powder, including: After mixing the ingredients according to the predetermined raw material formula, sodium carboxymethyl cellulose, sodium tripolyphosphate and water are added and wet ball milled to a fineness of 0.1-0.3% on a 325 mesh sieve, and spray dried to obtain a glaze powder; Alternatively, the raw materials are mixed according to a predetermined formula and then conveyed to a Raymond mill for fine grinding to a fineness of 0.1-0.3% with a 325-mesh sieve residue to obtain a glaze powder.

4. The method for preparing the secondary sintered microcrystalline ceramic glaze according to claim 1, characterized in that: The glaze powder is calcined to obtain a sintered material, comprising: The glaze powder is calcined at a temperature of 1000-1150° C. to obtain a sintered material.

5. The method for preparing the secondary sintered microcrystalline ceramic glaze according to claim 1, characterized in that: The microcrystalline ceramic glaze formula comprises, by weight percentage: Kaolin 8~12%, sintered material 60~90%, ultrafine corundum powder 0~5%, ultrafine alumina powder 0~5%, calcined kaolin 0~8%, potassium feldspar 0~30%, sodium feldspar 0~20%, wollastonite 0~5%, burned talc 0~8%, dolomite 0~10%, calcite 0~12%, barium carbonate 0~8%, strontium carbonate 0~5%, zinc oxide 0~8%.

6. The method for preparing the twice-sintered microcrystalline ceramic glaze according to claim 1, characterized in that: The glaze slurry is applied to a green brick and then subjected to secondary calcination to obtain a microcrystalline ceramic glaze, comprising: After the glaze slurry is applied to the brick, secondary calcination is performed at a temperature of 1140-1230° C. to obtain a microcrystalline ceramic glaze.

7. The method for preparing the twice-sintered microcrystalline ceramic glaze according to claim 1, characterized in that: The glaze slurry is applied to a green brick and then subjected to secondary calcination to obtain a microcrystalline ceramic glaze, comprising: If the glaze slurry is prepared from the sintered material prepared from the first raw material formula, the glaze slurry is applied to the brick and then secondary calcined at a temperature of 1190° C. to 1230° C. to obtain a microcrystalline ceramic glaze; If the glaze slurry is prepared from the sintered material prepared from the second raw material formula, the glaze slurry is applied to the brick and then secondary calcined at a temperature of 1140° C. to 1170° C. to obtain a microcrystalline ceramic glaze.

8. A microcrystalline ceramic glaze, characterized in that: The microcrystalline ceramic glaze is prepared based on the preparation method of the secondary sintered microcrystalline ceramic glaze according to any one of claims 1 to 7.

9. A microcrystalline ceramic glazed tile, characterized in that: The microcrystalline ceramic glaze tile is applied with the microcrystalline ceramic glaze according to claim 8.

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