Low-temperature glaze and glazing process thereof

Abstract

The present invention provides a low-temperature glaze and a glazing process thereof, relating to the field of ceramic glaze technology. The low-temperature glaze comprises, by weight, 90-100 parts of lead-free boron low-temperature frit, 5-10 parts of Suzhou clay, 3-5 parts of a dispersant, 3-5 parts of lithium carbonate, 3-5 parts of boric acid, 32-38 parts of water, and 6-10 parts of an organic binder. The low-temperature glaze of the present invention has stable quality and can be vitrified at 650-700°C to produce a glossy finish. The low-temperature glaze and glazing process are primarily used in functional ceramics, selenium-rich glaze ceramics, and sterilized glaze ceramics. The glaze has strong adhesion, breaking the traditional practice of glazing a surface with zero water absorption during vitrification, thereby improving the strength of the ceramic.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic glazes, in particular to a low-temperature glaze and a glazing process thereof. Background Art

[0002] The development of ceramics has a close and long-standing connection with human progress. It is a symbol of the era of human civilization. Ceramics are widely used in various fields due to their many advantages such as excellent smoothness and density. After experiencing the baptism of the Tang, Song, Yuan, Ming and Qing dynasties, ceramic glaze has formed a unique artistic expression form.

[0003] Currently, ceramic glazes are generally fired at high temperatures and for long periods of time, significantly increasing energy consumption, wasting resources, and polluting the environment. For example, traditional industrial ceramics, widely produced and used both domestically and internationally for daily use, fine art, and architectural applications, are fired at temperatures as high as 1280-1380°C, with firing cycles of 16-20 hours. While some researchers have developed low-temperature glazes, these sintering temperatures remain relatively high.

[0004] Selenium-rich and antibacterial functional ceramics contain selenium, an antioxidant that enhances human immunity, and graphene, a material with antibacterial and sterilizing properties. However, since selenium and graphene cannot survive temperatures above 700°C, otherwise their structures will be destroyed and their functions will be affected. Existing glazes require sintering at temperatures above 700°C to achieve vitrification, but this treatment compromises the functional ceramic's properties. Therefore, there is a need for a low-temperature glaze specifically for selenium-rich and antibacterial functional ceramics. Summary of the Invention

[0005] The object of the present invention is to provide a low-temperature glaze with stable quality, which can be vitrified at 650-700°C and produce gloss.

[0006] Another object of the present invention is to provide a glazing process with strong adhesion, breaking the innovation of glazing the tread surface with vitrification and zero water absorption, and improving the strength of the ceramic.

[0007] The present invention solves the technical problem by adopting the following technical solutions.

[0008] The invention provides a low-temperature glaze, which comprises the following raw materials by weight: 90-100 parts of lead-free boron low-temperature frit, 5-10 parts of Suzhou clay, 3-5 parts of dispersant, 3-5 parts of lithium carbonate, 3-5 parts of boric acid, 32-38 parts of water and 6-10 parts of organic binder.

[0009] The present invention provides a glazing process, comprising the following steps:

[0010] The raw materials of low-temperature glaze are ground in a wet ball mill for 15-25 minutes to a grinding fineness of 0.3-0.5% to obtain glaze slurry;

[0011] The body is glazed by dipping, pouring or spraying, with a thickness of 0.5-1mm, and then dried, sintered and cooled naturally.

[0012] The present invention has at least the following beneficial effects:

[0013] The low-temperature glaze, made from lead-free boron-free low-temperature frit and low-temperature mineral materials such as lithium carbonate and boric acid, can lower the melting temperature of the glaze, enabling it to vitrify at 650-700°C, creating a lustrous finish. This allows it to be used in selenium-enriched and antibacterial ceramics without affecting the selenium and graphene present, maintaining the functional properties of the ceramics. The addition of Suzhou clay, a dispersant, and an organic binder enhances the stability of the low-temperature glaze. Furthermore, the low-temperature glaze can be used for porcelain repair.

[0014] In this invention, during the glazing process, selenium, an element with antioxidant properties that enhances human immunity, is mixed into the low-temperature glaze at a certain ratio. The element adheres to the porcelain body, creating a selenium-rich functional ceramic. Furthermore, a certain amount of graphene, a material with antibacterial and sterilizing properties, is mixed into the low-temperature glaze at a certain ratio. The material adheres to the porcelain body, creating an antibacterial and sterilizing functional ceramic. The functional glaze is then applied to the porcelain body with zero water absorption using an organic binder through a glazing process involving dipping, pouring, or spraying, resulting in a ceramic with excellent strength and functionality. DETAILED DESCRIPTION

[0015] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0016] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to specific embodiments.

[0017] A low-temperature glaze comprises the following raw materials, calculated by weight: 90-100 parts of lead-free boron low-temperature frit, 5-10 parts of Suzhou clay, 3-5 parts of dispersant, 3-5 parts of lithium carbonate, 3-5 parts of boric acid, 32-38 parts of water and 6-10 parts of organic binder.

[0018] Lead-free boron low-temperature frit refers to an inorganic vitrified mixture formed by rapidly cooling the frit using water quenching or water-cooled metal rolling mill. It is used in glazes to help form a more uniform glaze layer at a lower temperature, thereby improving the surface quality and color uniformity of the glaze.

[0019] Suzhou clay can improve the shaping and compressive strength of glazes, greatly increase the lubrication effect, and greatly enhance the suspension and stability, so that the resulting ceramics have delicate porcelain texture, soft color, smooth glaze and good light transmittance.

[0020] Lithium carbonate provides lithium oxide, which has a strong fluxing ability and helps cool the glaze. Furthermore, when lithium carbonate is melted with a lead-free boron low-temperature frit, the lithium ions penetrate the electron shells of the anions, effectively reducing the viscosity of the frit and acting as a flux. After glazing, the lithium ions also increase the electrical conductivity of the glaze, resulting in a lower refractive index and dispersion, and improving the chemical stability of the glaze.

[0021] Boric acid can reduce the thermal expansion of glaze and lower the curing temperature of glaze, thereby preventing cracking and deglazing and improving the gloss and fastness of ceramic products.

[0022] After glazing and drying, semi-finished ceramic products, thanks to the presence of appropriate amounts of soluble salts and plastic clay in the glaze, will not break during handling. However, the brittle nature of most dry glaze layers makes them susceptible to breakage during handling, decoration, repair, and storage before pre-firing. Adding an organic binder to the glaze, utilizing its loose particle structure to create a cementing effect, strengthens the glaze's resistance to breakage and friction, and reduces the loss of semi-finished products during production. Furthermore, organic binders can enhance the bond between the glaze and the body, preventing the glaze from shedding.

[0023] Specifically, the dispersant is sodium tripolyphosphate. Sodium tripolyphosphate ensures a more even mixing of the raw materials, improving the uniformity of the glaze. It also helps conceal imperfections in the body, significantly enhancing the decorative quality of the product. It effectively prevents the dissolution of harmful substances in the pigment, enhancing the ceramic's antibacterial, antistatic, and luminous properties. Sodium tripolyphosphate also stabilizes glaze slurry properties, controls slurry viscosity, improves glaze thixotropy, overcomes glaze precipitation and delamination, enhances wettability, controls drying time, and increases the strength of the glaze layer on the body, ensuring consistent glaze thickness and uniformity.

[0024] A glazing process comprises the following steps:

[0025] The raw materials of low-temperature glaze are ground in a wet ball mill for 15-25 minutes, with a material-to-ball ratio of 1:(1.5-2), and the fineness of the 10,000-hole sieve is 0.3-0.5%, and the specific gravity is 1.65-1.70g / cm 3, glaze slurry with a flow rate of 35-40s;

[0026] The body is glazed by dipping, pouring or spraying, with a thickness of 0.5-1 mm, and then dried at 70-90° C. to a moisture content of less than 1%, sintered at 650-700° C. for 8-10 hours, and cooled naturally.

[0027] The glaze slurry prepared by the above process has good consistency and suspension, which can improve the adhesion ability of the glaze slurry, improve the bonding strength between the glaze slurry and the blank, and prevent cracking and deglazing. After ball milling and screening, the glaze slurry can have a suitable fineness. The finer the glaze slurry, the better the suspension of the slurry, the correspondingly lower the melting temperature of the glaze, the glaze blank adheres tightly and the two react fully with each other, thereby improving the glaze layer structure and improving the quality. In this way, the glaze slurry can be avoided from being too fine. If the glaze slurry is too fine, the viscosity will be too large, and it is easy to form an overly thick glaze layer when dipping the glaze. In addition, it is difficult to shake off the remaining slurry when the blank is taken out of the glaze, resulting in local glaze accumulation, cracking of the glaze layer during drying, and shrinkage or falling off of the glaze layer after firing. And under the above-mentioned glaze slurry specific gravity, the glazing speed can be better controlled, and then the thickness of the glaze layer can be controlled to obtain ceramics with a smooth glaze surface.

[0028] During glazing, selenium, an antioxidant and immune-boosting element, can be incorporated into the low-temperature glaze in a specific proportion. This element adheres to the porcelain body, creating a selenium-rich functional ceramic. Graphene, a material with antibacterial and sterilization properties, can also be incorporated into the low-temperature glaze in a specific proportion. This material adheres to the porcelain body, creating a ceramic with both antibacterial and sterilization properties. Using an organic binder, the functional glaze is then applied through a dipping, sprinkling, or spraying process to adhere to the porcelain body, resulting in a ceramic with excellent strength and functionality.

[0029] The raw materials of the embryo body include 25-30% of kaolin, 20-40% of feldspar, 20-30% of quartz and 10-25% of clay by mass.

[0030] Kaolin primarily contains Al₂O₃, which promotes the formation of mullite, improving the chemical stability and sintering strength of the green body. During the firing process, kaolin decomposes to form mullite, which forms the primary framework for green body strength. This prevents product degeneration, broadens the firing temperature range, and imparts a certain degree of whiteness to the green body. Kaolin also imparts excellent formability to the mud cake, facilitating turning and grouting, making it easier to form.

[0031] Feldspar can shorten the drying time of the green body, reduce the shrinkage and deformation of the green body during drying, and also lower the firing temperature of the green body. It melts into feldspar glass at high temperature, fills the pores between the green body particles, bonds the particles to make the green body dense, helps to improve the mechanical properties of the green body, and can promote the melting and mutual penetration of quartz and kaolin minerals.

[0032] Quartz in the blank modifies the plasticity of the mud cake and reduces shrinkage during drying, shortening drying time. During firing, the thermal expansion of quartz offsets the blank's shrinkage, preventing the blank from warping or deformation. Quartz has a strong chemical affinity at high temperatures and can combine with a variety of other oxides. Its high liquid viscosity at high temperatures increases the blank's bonding ability, while also enhancing its mechanical strength and transparency.

[0033] Clay is the main component during sintering of the green body, which can make the grouting mud and glaze suspended and stable, and it is in the form of finely dispersed particles with binding properties.

[0034] The preparation method of the green body is as follows: the raw materials are crushed in a wet ball mill, the material: ball: water ratio is 1: (1.5-2): 0.7, the ball milling time is 20 hours, the grinding fineness is 3-5% of the 10,000-hole sieve, and the specific gravity is 1.5-1.6g / cm 3 The green pulp is filtered to a mud cake with a moisture content of 25-30%, homogenized and aged for 1-2 months, vacuumed 2-3 times at a vacuum degree of 95%, and formed into a green product, which is first dried at 60-80°C for 30-60min, then dried at 80-100°C to a moisture content of less than 1%, and then sintered at 750-800°C for 6-8h.

[0035] The milled slurry is continuously stirred in the slurry storage tank to prevent sedimentation. Homogenization and aging can even out the moisture content of the mud cake, allowing the sodium humate to alcoholize and increasing the plasticity of the blank. Vacuuming can expel air from the mud cake, further balancing the moisture content and creating a denser structure, further improving the plasticity of the blank. Molding fixes the geometric shape of the blank, but since the blank contains a certain amount of moisture, it still has a certain degree of plasticity and is prone to collapse. Therefore, it is first dried at 60-80°C for 30-60 minutes to dehydrate and set the shape.

[0036] After dehydration and shaping, and before re-drying, the rough, uneven surface of the green body, with its inaccurate dimensions, must be fine-tuned with a knife and sandpaper, and brushed with water to smooth the surface and achieve precise dimensions. Finally, sintering evaporates mechanical crystallization water, carbonizes organic matter, decomposes some carbonate and sulfate substances, and transforms quartz crystals, reducing the green body's weight, improving its mechanical strength, and reducing breakage.

[0037] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0038] Example 1

[0039] A glazing process comprises the following steps:

[0040] 1. Body preparation

[0041] 100kg raw materials: 30kg kaolin, 40kg feldspar, 20kg quartz and 10kg clay;

[0042] 1.1. The raw materials were crushed in a wet ball mill with a material: ball: water ratio of 1:1.5:0.7 and a ball milling time of 20 hours. The fineness of the milled material was 3% after 10,000-hole sieve, and the specific gravity was 1.5 g / cm 3 of green pulp;

[0043] 1.2. Filter the slurry to a cake with a moisture content of 25%, homogenize and age for 1 month, and evacuate the mixture twice at a vacuum degree of 95% to obtain a slurry with a moisture content of 20%. Use rolling, spinning, throwing or slip casting to obtain a green product.

[0044] 1.3. Dry the blank at 60℃ for 50min. After drying and setting, use a knife and sandpaper to fine-tune the surface of the blank, and brush it with water to make the surface smooth and the size accurate. Then dry it at 80℃ until the moisture content is less than 1%, and then sinter it at 750℃ for 6h.

[0045] 2. Preparation of low-temperature glaze

[0046] Raw materials: 90kg lead-free boron low-temperature frit, 5kg Suzhou clay, 3kg sodium tripolyphosphate, 3kg lithium carbonate, 3kg boric acid, 32kg water and 6kg organic binder;

[0047] The raw materials were weighed according to the formula ratio and crushed in a wet ball mill for 15 minutes. The material-ball ratio was 1:1.5. The fineness of the ground product was 0.3% after 10,000-hole sieve. The specific gravity was 1.65 g / cm 3 , glaze slurry with a flow rate of 35s;

[0048] 3. Glazing

[0049] Apply glaze slurry to the body by dipping, pouring or spraying, and evenly adhere the glaze slurry to the surface of the porcelain body using conventional, normal pressure and conventional operation process. The glaze slurry thickness is 0.5mm, and then dried at 70℃ to a moisture content of less than 1%, sintered at 650℃ for 8h, and naturally cooled to obtain the finished product.

[0050] Example 2

[0051] A glazing process comprises the following steps:

[0052] 1. Body preparation

[0053] 100kg raw materials: 25kg kaolin, 35kg feldspar, 25kg quartz and 15kg clay;

[0054] 1.1. The raw materials were crushed in a wet ball mill with a material: ball: water ratio of 1:1.8:0.7 and a ball milling time of 20 hours. The fineness of the milled material was 4% after 10,000-hole sieve, and the specific gravity was 1.55 g / cm 3 of green pulp;

[0055] 1.2. Filter-press the slurry to a mud cake with a moisture content of 28%, homogenize and age it for 1.5 months, and evacuate the mixture three times at a vacuum degree of 95% to obtain a mud cake with a moisture content of 21%. Use rolling, spinning, throwing or slip casting to obtain a green product.

[0056] 1.3. Dry the blank at 70℃ for 40min. After drying and setting, use a knife and sandpaper to finely trim the surface of the blank. Use a brush to brush water to make the surface smooth and the size accurate. Then dry it at 90℃ until the moisture content is less than 1%. Then sinter it at 780℃ for 7h.

[0057] 2. Preparation of low-temperature glaze

[0058] Raw materials: 95kg lead-free boron low-temperature frit, 8kg Suzhou clay, 4kg sodium tripolyphosphate, 4kg lithium carbonate, 4kg boric acid, 35kg water and 8kg organic binder;

[0059] The raw materials were weighed according to the formula ratio and crushed in a wet ball mill for 20 minutes. The material-ball ratio was 1:1.6, and the fineness of the sieve was 0.4%. The specific gravity was 1.68 g / cm 3 , glaze slurry with a flow rate of 38s;

[0060] 3. Glazing

[0061] Apply glaze slurry to the embryo by dipping, pouring or spraying, and evenly adhere the glaze slurry to the surface of the porcelain body using conventional, normal pressure and conventional operation process. The glaze slurry thickness is 0.6mm, and then it is dried at 80℃ to a moisture content of less than 1%, sintered at 660℃ for 9 hours, and naturally cooled to obtain the finished product.

[0062] Example 3

[0063] A glazing process comprises the following steps:

[0064] 1. Body preparation

[0065] 100kg raw materials: 30kg kaolin, 25kg feldspar, 30kg quartz and 15kg clay;

[0066] 1.1. The raw materials were crushed in a wet ball mill with a material: ball: water ratio of 1:1.6:0.7 and a ball milling time of 20 hours. The fineness of the milled product was 5% after 10,000-hole sieve, and the specific gravity was 1.58 g / cm 3 of green pulp;

[0067] 1.2. Filter-press the slurry to a mud cake with a moisture content of 27%, homogenize and age it for 1.8 months, and evacuate the mixture three times at a vacuum degree of 95% to obtain a slurry with a moisture content of 20%. Use rolling, spinning, throwing or slip casting to obtain a green product.

[0068] 1.3. Dry the blank at 75℃ for 45min. After drying and setting, use a knife and sandpaper to fine-tune the surface of the blank, and brush it with water to make the surface smooth and the size accurate. Then dry it at 95℃ until the moisture content is less than 1%, and then sinter it at 760℃ for 7.5h.

[0069] 2. Preparation of low-temperature glaze

[0070] Raw materials: 98kg lead-free boron low-temperature frit, 7kg Suzhou clay, 4kg sodium tripolyphosphate, 4kg lithium carbonate, 4kg boric acid, 36kg water and 9kg organic binder;

[0071] The raw materials were weighed according to the formula ratio and crushed in a wet ball mill for 22 minutes. The material-ball ratio was 1:1.6. The fineness of the ground product was 0.4% after 10,000-hole sieve. The specific gravity was 1.69 g / cm 3 , glaze slurry with a flow rate of 38s;

[0072] 3. Glazing

[0073] Apply glaze slurry to the embryo by dipping, pouring or spraying, and evenly adhere the glaze slurry to the surface of the porcelain body using conventional, normal pressure and conventional operation process. The glaze slurry thickness is 0.7mm, and then it is dried at 85℃ to a moisture content of less than 1%, sintered at 660℃ for 9 hours, and naturally cooled to obtain the finished product.

[0074] Example 4

[0075] A glazing process comprises the following steps:

[0076] 1. Body preparation

[0077] 100kg raw materials: 30kg kaolin, 30kg feldspar, 20kg quartz and 20kg clay;

[0078] 1.1. The raw materials were crushed in a wet ball mill with a material: ball: water ratio of 1:2:0.7 and a ball milling time of 20 hours. The fineness of the milled material was 5% after 10,000-hole sieve, and the specific gravity was 1.6 g / cm 3 of green pulp;

[0079] 1.2. Filter the slurry to a cake with a moisture content of 30%, homogenize and age for 2 months, and evacuate the mixture 3 times at a vacuum degree of 95% to obtain a slurry with a moisture content of 22%. Use rolling, spinning, throwing or slip casting to obtain a green product.

[0080] 1.3. Dry the blank at 80℃ for 60min. After drying and setting, use a knife and sandpaper to fine-tune the surface of the blank, and brush it with water to make the surface smooth and the size accurate. Then dry it at 100℃ until the moisture content is less than 1%, and then sinter it at 800℃ for 8h.

[0081] 2. Preparation of low-temperature glaze

[0082] Raw materials: 100kg lead-free boron low-temperature frit, 10kg Suzhou clay, 5kg sodium tripolyphosphate, 5kg lithium carbonate, 5kg boric acid, 38kg water and 10kg organic binder;

[0083] The raw materials were weighed according to the formula ratio and crushed in a wet ball mill for 25 minutes. The material-ball ratio was 1:2 and the fineness of the mill was 0.5% after 10,000-hole sieve. The specific gravity was 1.70 g / cm 3 , glaze slurry with a flow rate of 40s;

[0084] 3. Glazing

[0085] Apply glaze slurry to the embryo by dipping, pouring or spraying, and evenly adhere the glaze slurry to the surface of the porcelain body using conventional, normal pressure and conventional operation process. The glaze slurry thickness is 1mm, and then dried at 90℃ to a moisture content of less than 1%, sintered at 700℃ for 10 hours, and naturally cooled to obtain the finished product.

[0086] Test results

[0087] The finished products prepared in Examples 1-4 were tested for water absorption, abrasion resistance, linear expansion coefficient, and glossiness, respectively, according to the following testing standards: GB / T 3299-1996, GB / T 3810.7, GB / T16535-2008, and GB / T 3532-2009. The test results are as follows:

[0088] Table 1 Glaze performance test results

[0089]

[0090] As shown in Table 1, the glazes of the products prepared in Examples 1-4 have low water absorption, good wear resistance, linear Penghua coefficient, and glossiness, indicating that the low-temperature glaze and glazing process of the present invention can produce products with low water absorption and good glossiness.

[0091] In summary, the low-temperature glaze of the present invention, using lead-free boron-free low-temperature frit and low-temperature mineral materials such as lithium carbonate and boric acid as raw materials, can lower the melting temperature of the glaze, enabling vitrification at 650-700°C and producing a lustrous finish. This allows the glaze to be used in selenium-enriched and antibacterial functional ceramics without affecting the selenium and graphene present therein, thus maintaining the functional properties of the ceramics. The addition of Suzhou clay, a dispersant, and an organic binder can enhance the stability of the low-temperature glaze.

[0092] The glazing process of the present invention allows selenium, an antioxidant and immune-enhancing element, to be incorporated into the low-temperature glaze at a specific ratio. The element adheres to the vitrified body, creating a selenium-rich functional ceramic. Furthermore, graphene, a material with antibacterial and sterilizing properties, is incorporated into the low-temperature glaze at a specific ratio. This material adheres to the vitrified body, creating an antibacterial and sterilizing ceramic. The functional glaze is then applied to the vitrified body with zero water absorption using an organic binder through a glazing process involving dipping, pouring, or spraying, resulting in a ceramic with excellent strength and functionality.

[0093] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

Claims

1. A low-temperature glaze, characterized in that: The invention comprises the following raw materials in parts by weight: 90-100 parts of lead-free boron low-temperature frit, 5-10 parts of Suzhou clay, 3-5 parts of dispersant, 3-5 parts of lithium carbonate, 3-5 parts of boric acid, 32-38 parts of water and 6-10 parts of organic binder; the dispersant is sodium tripolyphosphate.

2. A low-temperature glaze glazing process according to claim 1, characterized in that: The steps are as follows: The raw materials of low-temperature glaze are ground in a wet ball mill for 15-25 minutes to a grinding fineness of 0.3-0.5% to obtain glaze slurry; The body is glazed by dipping, pouring or spraying, with a thickness of 0.5-1mm, and then dried, sintered and cooled naturally.

3. The glazing process according to claim 2, characterized in that: When the wet ball mill is used for crushing, the material-to-ball ratio is 1:(1.5-2).

4. The glazing process according to claim 2, characterized in that: The specific gravity of the glaze slurry is 1.65-1.70 g / cm 3 , flow rate is 35-40s.

5. The glazing process according to claim 2, characterized in that: Dry at 70-90℃ until the moisture content is less than 1%, and sinter at 650-700℃ for 8-10h.

6. The glazing process according to claim 2, characterized in that: The green body raw materials include 25-30% kaolin, 20-40% feldspar, 20-30% quartz and 10-25% clay by mass.

7. The glazing process according to claim 6, characterized in that: The preparation method of the green body is as follows: the raw materials are crushed in a wet ball mill, the material: ball: water ratio is 1: (1.5-2): 0.7, the ball milling time is 20 hours, the grinding fineness is 3-5%, and the specific gravity is 1.5-1.6 g / cm 3 The green slurry is filtered, homogenized and aged for 1-2 months, vacuumed, and formed into a green product, which is then dried and sintered to obtain the product.

8. The glazing process according to claim 7, characterized in that: The green pulp is filter-filtered to obtain a mud cake with a moisture content of 25-30%, and vacuumed 2-3 times at a vacuum degree of 95%.

9. The glazing process according to claim 7, characterized in that: The green product is first dried at 60-80° C. for 30-60 minutes, then dried at 80-100° C. until the moisture content is less than 1%, and then sintered at 750-800° C. for 6-8 hours.

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