Heat-resistant ceramic marmite and preparation method thereof

Abstract

The invention relates to the technical field of ceramics, in particular to a preparation method of a heat-resistant ceramic marmite. The heat-resistant ceramic marmite is composed of a green body and a glaze surface, and the green body is prepared from, by weight, 30-35 parts of fused quartz, 8-10 parts of petalite, 9-11 parts of kaolin, 19-21 parts of washed illite clay, 5-7 parts of sepiolite, 5-6 parts of andalusite, 7-9 parts of coal gangue, 0.2-0.7 part of zinc spinel and 2-3 parts of talc; the glaze surface is prepared from the following raw materials in parts by weight: 18 to 20 parts of fused quartz, 14 to 16 parts of petalite, 12 to 14 parts of kaolin, 5 to 6 parts of calcium oxide, 1.5 to 2 parts of zinc oxide, 1 to 1.5 parts of strontium oxide, 8 to 10 parts of spodumene, 0.6 to 0.8 part of lanthanum oxide, 8 to 10 parts of ZrSiO4 coated Al2O3 and 1.2 to 1.8 parts of pigment. The prepared ceramic marmite has the advantages of matt appearance, higher thermal stability, low water absorption rate and excellent comprehensive performance, and is not easy to crack and wear.

Description

Technical Field

[0001] The invention relates to the technical field of ceramics, and in particular to a method for preparing a heat-resistant ceramic casserole. Background Art

[0002] Clay pots have a long history in my country and are an important cooking utensil in people's daily dining life. Clay pots can be divided into earthenware clay pots, ceramic clay pots, purple clay pots and stone pots according to their materials. Clay pots can be divided into glazed clay pots and unglazed clay pots according to whether they have glaze or not. Among them, glazed ceramic clay pots are durable, safe in material and moderate in weight.

[0003] By using a matte brown glaze, the overall appearance of the ceramic casserole can also be given the style of an earthenware casserole, achieving a casserole that is both healthy, practical, and aesthetically pleasing, and is increasingly favored by the catering industry and families. In addition, compared to general daily-use ceramics, the key to preparing ceramic casseroles lies in improving the thermal shock resistance of the ceramic blank. Traditional casseroles are mainly made of quartz, feldspar, and clay, and spodumene is added to reduce the thermal expansion coefficient of the casserole, thereby improving thermal shock resistance. However, with the accelerated pace of life and the improvement of living standards, casseroles are required to be able to be used stably at higher heating temperatures, not easily break or wear out when dropped or bumped during daily use, not easily absorb food and soup, and be easy to clean.

[0004] Based on this, the present application aims to conduct in-depth research on the manufacturing process and raw material selection of ceramic casseroles, so that the prepared ceramic casseroles have the matte appearance of earthenware casseroles, and have higher thermal stability, are not easy to crack or wear, and have lower water absorption. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a heat-resistant ceramic casserole and a preparation method thereof. The prepared ceramic casserole has a matte appearance of an earthenware casserole, high thermal stability, is not easy to crack or wear, and has low water absorption.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The present application provides a heat-resistant ceramic casserole, which is composed of a body and a glaze, wherein the body comprises the following raw materials in parts by weight: 30-35 parts of fused quartz, 8-10 parts of petalite, 9-11 parts of kaolin, 19-21 parts of washed illite clay, 5-7 parts of sepiolite, 5-6 parts of andalusite, 7-9 parts of coal gangue, 0.2-0.7 parts of galachite, and 2-3 parts of talc; The glaze comprises the following raw materials in parts by weight: 18 to 20 parts of fused quartz, 14 to 16 parts of petalite, 12 to 14 parts of kaolin, 5 to 6 parts of calcium oxide, 1.5 to 2 parts of zinc oxide, 1 to 1.5 parts of strontium oxide, 8 to 10 parts of spodumene, 0.6 to 0.8 parts of lanthanum oxide, 8 to 10 parts of ZrSiO4@Al2O3 and 1.2 to 1.8 parts of colorant.

[0007] The heat-resistant high-temperature ceramic casserole body uses fused quartz with different particle size gradations and low thermal expansion coefficient as aggregate, and uses lithium feldspar with low thermal expansion coefficient as low-temperature fluxing agent to give the matrix good thermal shock resistance; kaolin, washed illite clay and coal gangue provide plasticity to facilitate molding while reducing firing shrinkage; lithium feldspar and talc form a low-temperature eutectic system, which jointly promote dissolution and promote the densification of the body; garnet improves toughness and reduces sintering shrinkage, zinc spinel reduces sintering stress, cracks and firing defects, and the nanofiber structure of sepiolite can enhance the toughness of the body, and finally forms a mullite crystal phase as the main skeleton of the body. The fired product has a low firing shrinkage rate and has high strength and thermal stability.

[0008] The glaze formula has an important influence on the thermal stability of ceramic casseroles. In addition, the glaze needs to have a good match with the blank before firing so that it will not crack and ensure good performance. The glaze of this application uses fused quartz as the aggregate, and uses lithium feldspar, calcium oxide, zinc oxide and strontium oxide as low-temperature fluxes to reduce the firing temperature. Finer-grained quartz and kaolin are selected to balance the plasticity. The core-shell structure ZrSiO4@Al2O3 is added to enhance the toughness of the glaze. It provides a matte texture as a dispersed phase. Lanthanum oxide can optimize high-temperature viscosity to reduce pinhole defects and reduce the water absorption of the glaze layer. Strontium oxide plays a role in fixing color. The use of the above-mentioned glaze raw materials can promote the formation of the blank-glaze intermediate layer and the glaze layer. The provided glaze has a high degree of thermal expansion matching with the blank, a low sintering defect rate, high shock resistance, low water absorption, and high toughness. The glaze has a matte coffee tone, which is very beautiful like the matte of ancient pottery.

[0009] Furthermore, in the blank, the fused quartz material uses fused quartz material with different particle size distributions, including 35-40% of 20-60 mesh coarse particles and 60-65% of 80-120 mesh fine particles, so that the coarse particles enhance the overall fluidity of the blank and the fine particles improve the plasticity.

[0010] Furthermore, in the glaze, the mesh number of the fused quartz is 100 to 200 meshes.

[0011] Furthermore, the colorant is obtained by mixing red iron oxide and black manganese oxide in a mass ratio of 1:0.15 to 0.25.

[0012] Ceramic casseroles need to withstand rapid temperature changes, long-term dry firing or high-temperature cooking during use. Nano zirconium silicate has a very low thermal expansion coefficient and a high melting point. It can maintain a granular state during the firing process and fill in the ceramic phase interface, which can greatly improve the thermal shock resistance of the glaze. The addition of nano zirconium silicate can also cause strong scattering of light, thereby achieving a matte effect on the glaze. Ceramic casseroles are easily bumped and damaged during use and cleaning. Adding alumina is an effective way to improve the strength and durability of the glaze; however, directly adding nano zirconium silicate and alumina to the glaze is prone to aggregation, resulting in stress concentration and causing pinholes, ripples, peeling and cracks in the glaze. This application uses ZrSiO4@Al2O3 as a glaze raw material, and the preparation method of ZrSiO4@Al2O3 includes the following steps: (1) D 50 Anhydrous ethanol is added to zirconium silicate with a size of 100 to 200 nm, with the mass volume ratio of zirconium silicate to ethanol being 1:30 to 50, and then polyvinyl pyrrolidone (1 to 2% by weight of the zirconium silicate) is added, and ultrasonic treatment is performed for 15 to 30 minutes to obtain a zirconium silicate dispersion. (2) AlCl3·6H2O was dissolved in ethanol to prepare an aluminum chloride solution with a concentration of 0.1-0.2 mol / L, ethanolamine was added in a molar ratio of aluminum chloride to ethanolamine of 1:1, and the mixture was stirred at 50-60°C for 1.5-2.5 hours to obtain an aluminum sol; (3) Add zirconium silicate dispersion to aluminum sol, control the molar ratio of zirconium silicate to aluminum chloride to be 1:0.05-0.4, ultrasonically treat the mixture for 15-30 minutes, heat the ultrasonically treated mixture to 60-70°C, slowly drop ammonia water into the mixture while stirring to adjust the pH to 8-9, let it stand for 12-24 hours, filter, dry at 75-85°C for 12-24 hours, heat to 450-500°C at a heating rate of 1-5°C / min, and calcine for 2-3 hours.

[0013] This application adopts the above-mentioned method to prepare ZrSiO4@Al2O3, and the two have a strong bonding effect. The core-shell structure can realize the dispersion of nano-zirconium silicate in the glaze, and improve the glaze firing shrinkage difference and firing defects caused by the agglomeration of nano-zirconium silicate in the glaze production; ZrSiO4@Al2O3 forms nano-zirconium silicate and aluminum oxide in situ during the firing process, which can be filled into the phase gaps of the glaze layer together, reducing the gloss of the glaze to achieve a matte effect, and improving the toughness and strength of the glaze layer, and improving thermal shock resistance.

[0014] Furthermore, the preparation method of the water-washed illite clay comprises adding 200-mesh illite clay to water to prepare a slurry with a concentration of 20-30%, then adding 0.3-0.5% of water glass and 0.1-0.2% of hexametaphosphoric acid based on the weight of the illite clay, adjusting the pH to 8-9 with a sodium hydroxide solution, stirring at 300-500 rpm for 1-2 hours, filtering with a 200-mesh sieve, and collecting the slurry under the sieve; pressing the slurry under the sieve to a moisture content of 20-25%, and then standing for 3-5 days for homogenization.

[0015] The present application also provides a method for preparing a heat-resistant ceramic casserole, comprising the following steps: S1. Weigh the raw materials of each billet according to the raw material ratio; S2. Add the raw materials of the blank except sepiolite into a rapid ball mill, add water according to the material, ball and water ratio of 1:1.5-2:0.4-0.45, use the rapid ball mill to ball mill the proportioned materials for 2.5-3.5 hours, then add sepiolite and continue ball milling for 0.5-1 hour to obtain a slurry; S3, the slurry after ball milling is aged for 2 to 5 days, and a vacuum clay machine is used for clay making, and the clay is poured into a gypsum mold for molding, and demolding is performed to obtain a wet blank; S4, drying the wet blank at room temperature for 10 to 12 hours for blanking, drying the wet blank at 50 to 90° C. for 24 to 48 hours, and blanking the dried blank again; S5. Weigh the other raw materials of the glaze except ZrSiO4@Al2O3 according to the formula, add them into a rapid ball mill, add water according to the material, ball and water ratio of 1:1.8-2.2:0.5-0.55, ball mill for 2-4 hours, then add ZrSiO4@Al2O3 and continue ball milling for 10-20 minutes. Aged for 12-24 hours to obtain a glaze slurry; S6. Place the green body on a wheelbarrow, pour the glaze slurry in the center of the green body, and use centrifugal force to evenly spread the glaze slurry on the surface of the green body, controlling the thickness of the glaze layer to 0.2-0.3 mm; S7. Place the glazed semi-finished product into a roller kiln for firing, and cool it down in the kiln.

[0016] Furthermore, the weight ratio of S2 intermediate material, balls and water is 1:1.5:0.4, and the weight ratio of S5 intermediate material, balls and water is 1:2:0.5.

[0017] The firing method has a significant impact on the performance of the casserole. By controlling the firing method, the various properties of the casserole can be achieved in an ideal state. Furthermore, the present application adopts a roller kiln firing method. The specific firing method is to heat the casserole to 730-770°C at a heating rate of 60-100°C / h and keep it warm for 2-3 hours, then heat the casserole to 1210-1290°C at a heating rate of 50-70°C / h and keep it warm for 13-15 hours, and then cool it to room temperature with the furnace. The specific method of cooling the casserole is to quickly cool it to 1010-1050°C at a cooling rate of 100-120°C / h and keep it warm for 10-20 minutes, then slowly cool it to 400-450°C at a cooling rate of 50-70°C / h, and finally cool it to room temperature at a cooling rate of 70-90°C / h.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the heat-resistant ceramic casserole provided by the present application is obtained by selecting the raw material formula and materials for the ceramic body and glaze, and the raw materials are subjected to the steps of blank preparation, ball milling, aging, clay kneading, molding, two-time blank trimming, glaze preparation, glazing and firing. By controlling the firing temperature and firing process, the obtained heat-resistant ceramic casserole has the matte appearance of ancient pottery, good impact toughness and glaze hardness, good thermal stability, and no lead and cadmium migration, ensuring durability and safety of use, low firing shrinkage, low water absorption, easy cleaning, and excellent comprehensive performance. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] The raw materials used in the following examples and comparative examples need to be crushed to a qualified particle size in advance, as shown below: Billet: Fused quartz materials with different particle size distributions are used, including 40% 40-mesh coarse particles and 60% 100-mesh fine particles, 120-mesh petalite, 200-mesh kaolin, 200-mesh illite clay, 40-mesh sepiolite, 60-mesh andalusite, 120-mesh coal gangue, 325-mesh galvanneal, and 200-mesh talc. Glaze: fused quartz powder 200 mesh, petalite 200 mesh, kaolin 325 mesh, calcium oxide 300 mesh, zinc oxide 300 mesh, strontium oxide 600 mesh, spodumene 325 mesh, lanthanum oxide D 50 2μm, pigment 600 mesh, zirconium silicate D 50 150nm, aluminum oxide D 50 is 100nm.

[0021] The preparation method of water-washed illite clay is as follows: 200-mesh illite clay is added with water to prepare a slurry with a concentration of 25%, 0.4% of water glass and 0.15% of hexametaphosphoric acid by weight of the illite clay are added, the pH is adjusted to 8 with a sodium hydroxide solution, the mixture is stirred at 300 rpm for 2 hours, filtered with a 200-mesh sieve, and the slurry under the sieve is collected; the slurry under the sieve is pressed to a moisture content of 25%, and then allowed to stand for 4 days for homogenization to obtain the obtained product.

[0022] Unless otherwise specified, the methods are conventional methods, and the raw materials can be obtained from public commercial channels unless otherwise specified.

[0023] Example 1 This embodiment provides a heat-resistant ceramic casserole, and the raw materials for its preparation are as follows in parts by weight: The raw material composition of the green body is as follows: 32 parts of fused quartz, 9 parts of petalite, 10 parts of kaolin, 20 parts of washed illite clay, 6 parts of sepiolite, 5.5 parts of andalusite, 8 parts of coal gangue, 0.5 parts of galvanneal, and 2.5 parts of talc. The glaze raw materials are as follows: 19 parts of fused quartz, 15 parts of petalite, 13 parts of kaolin, 5.5 parts of calcium oxide, 1.7 parts of zinc oxide, 1.3 parts of strontium oxide, 9 parts of spodumene, 0.7 parts of lanthanum oxide, 9 parts of ZrSiO4@Al2O3, and 1.5 parts of colorant, where the colorant is obtained by mixing red iron oxide and black manganese oxide in a mass ratio of 1:0.2. The preparation method of ZrSiO4@Al2O3 comprises the following steps: (1) D 50 Add anhydrous ethanol to zirconium silicate with a particle size of 150 nm, with the mass volume ratio of zirconium silicate to ethanol being 1:40, and then add polyvinyl pyrrolidone (1.5% by weight of the zirconium silicate), and perform ultrasonic treatment for 20 minutes to obtain a zirconium silicate dispersion. (2) AlCl3·6H2O was dissolved in ethanol to prepare an aluminum chloride solution with a concentration of 0.15 mol / L. Ethanolamine was added at a molar ratio of aluminum chloride to ethanolamine of 1:1, and the mixture was stirred at 55°C for 2 h to obtain an aluminum sol. (3) Add zirconium silicate dispersion to aluminum sol, control the molar ratio of zirconium silicate to aluminum chloride to be 1:0.2, ultrasonically treat the mixture for 20 minutes, heat the ultrasonically treated mixture to 65°C, slowly add ammonia water to the mixture while stirring to adjust the pH to 8.5, let it stand for 24 hours, filter it, dry it at 80°C for 24 hours, heat it to 500°C at a heating rate of 2°C / min, and calcine it for 2 hours.

[0024] The preparation method of the heat-resistant ceramic casserole comprises the following steps: S1. Weigh the raw materials of each billet according to the raw material ratio; S2, the raw materials of the blank except sepiolite are added to a rapid ball mill, water is added according to the material, ball and water ratio of 1:1.5:0.4, the proportioned materials are ball milled for 3 hours using a rapid ball mill, and then sepiolite is added and ball milled for 0.5 hours to obtain a slurry; S3, the ball-milled slurry was aged for 4 days, and a vacuum clay machine was used for clay making, and the clay was injected into a gypsum mold for molding, and demoulding was performed to obtain a wet blank; S4, drying the wet blank at room temperature for 12 hours to perform blanking, drying the wet blank at 80° C. for 36 hours, and performing blanking again on the dried blank; S5. Weigh the other raw materials of the glaze except ZrSiO4@Al2O3 according to the formula, add them into a rapid ball mill, add water according to the material, ball and water ratio of 1:2:0.5, ball mill for 3 hours, then add ZrSiO4@Al2O3 and continue ball milling for 15 minutes. Aged for 12 hours to obtain a glaze slurry; S6. Place the green body on a wheelbarrow, pour the glaze slurry in the center of the green body, and use centrifugal force to evenly spread the glaze slurry on the surface of the green body, controlling the thickness of the glaze layer to 0.25±0.03mm; S7. Place the glazed semi-finished product into a roller kiln for firing. Heat the temperature to 750°C at a heating rate of 80°C / h and keep it warm for 2.5 hours. Heat the temperature to 1250°C at a heating rate of 60°C / h and keep it warm for 14 hours. Cool the temperature rapidly to 1030°C at a cooling rate of 110°C / h and keep it warm for 15 minutes. Cool the temperature slowly to 420°C at a cooling rate of 60°C / h and finally cool to room temperature at a cooling rate of 80°C / h.

[0025] Example 2 This embodiment provides a heat-resistant ceramic casserole, and the raw materials for its preparation are as follows in parts by weight: The raw material composition of the green body is as follows: 30 parts of fused quartz, 10 parts of petalite, 11 parts of kaolin, 19 parts of washed illite clay, 7 parts of sepiolite, 5 parts of andalusite, 9 parts of coal gangue, 0.6 parts of galvanneal, and 2 parts of talc. The glaze raw materials are as follows: 18 parts of fused quartz, 14 parts of petalite, 14 parts of kaolin, 6 parts of calcium oxide, 1.5 parts of zinc oxide, 1 part of strontium oxide, 10 parts of spodumene, 0.6 parts of lanthanum oxide, 8 parts of ZrSiO4@Al2O3 and 1.8 parts of pigment, where the pigment is obtained by mixing red iron oxide and black manganese oxide in a mass ratio of 1:0.2. The preparation method of ZrSiO4@Al2O3 and the preparation method of the heat-resistant ceramic casserole are the same as those in Example 1.

[0026] Example 3 This embodiment provides a heat-resistant ceramic casserole, and the raw materials for its preparation are as follows in parts by weight: The raw material composition of the green body is as follows: 35 parts of fused quartz, 8 parts of petalite, 9 parts of kaolin, 21 parts of washed illite clay, 5 parts of sepiolite, 6 parts of andalusite, 7 parts of coal gangue, 0.4 parts of galvanneal, and 3 parts of talc. The glaze raw materials are as follows: 20 parts of fused quartz, 16 parts of petalite, 14 parts of kaolin, 5 parts of calcium oxide, 2 parts of zinc oxide, 1.5 parts of strontium oxide, 8 parts of spodumene, 0.8 parts of lanthanum oxide, 10 parts of ZrSiO4@Al2O3 and 1.2 parts of pigment, where the pigment is obtained by mixing red iron oxide and black manganese oxide in a mass ratio of 1:0.2. The preparation method of ZrSiO4@Al2O3 and the preparation method of the heat-resistant ceramic casserole are the same as those in Example 1.

[0027] Comparative Example 1 The method of Example 1 was followed, except that no andalusite was added to the green body raw material. The specific composition was as follows: 32 parts of fused quartz material, 9 parts of petalite, 10 parts of kaolin, 20 parts of washed illite clay, 6 parts of sepiolite, 8 parts of coal gangue, 0.5 parts of galvanneal, and 2.5 parts of talc.

[0028] Comparative Example 2 According to the method of Example 1, the difference is that the green body raw material does not add sepiolite, and the specific composition is as follows: The green body raw materials consist of: 32 parts fused quartz, 9 parts petalite, 10 parts kaolin, 20 parts washed illite clay, 5.5 parts andalusite, 8 parts coal gangue, 0.5 parts galvanneal, and 2.5 parts talc. Heat-resistant ceramic casserole preparation method S2 follows the following method: the green body raw materials are added to a rapid ball mill and water is added at a material: ball: water ratio of 1:1.5:0.4. The prepared materials are ball-milled in the rapid ball mill for 3.5 hours to obtain a slurry.

[0029] Comparative Example 3 The method of Example 1 was followed, except that ZrSiO4@Al2O3 was not added to the glaze raw materials. The specific composition was as follows: The glaze raw materials consisted of 19 parts of fused quartz, 15 parts of petalite, 13 parts of kaolin, 5.5 parts of calcium oxide, 1.7 parts of zinc oxide, 1.3 parts of strontium oxide, 9 parts of spodumene, 0.7 parts of lanthanum oxide, and 1.5 parts of a colorant, wherein the colorant was obtained by mixing red iron oxide and black manganese oxide in a mass ratio of 1:0.2. A heat-resistant ceramic casserole preparation method S5 was performed as follows: the glaze raw materials were weighed according to the formula and added to a rapid ball mill. Water was added in a material: ball: water ratio of 1:2:0.5. After ball milling for 3.25 hours, the glaze slurry was aged for 12 hours to obtain a glaze slurry.

[0030] Comparative Example 4 The method of Example 1 is the same as that of Example 1, except that zirconium silicate and aluminum oxide are directly added to the glaze raw materials. The glaze raw materials are composed of: 19 parts of fused quartz, 15 parts of petalite, 13 parts of kaolin, 5.5 parts of calcium oxide, 1.7 parts of zinc oxide, 1.3 parts of strontium oxide, 9 parts of spodumene, 0.7 parts of lanthanum oxide, zirconium silicate (D 50 150nm) 8.5 parts, aluminum oxide (D 50 100nm) 0.5 parts, and 1.5 parts of colorant. The colorant is a mixture of red iron oxide and black manganese oxide in a mass ratio of 1:0.2. Heat-resistant ceramic casserole preparation method S5 follows the following method: glaze raw materials are weighed according to the recipe and added to a rapid ball mill. Water is added in a ratio of 1:2:0.5 between glaze, balls, and water. After ball milling for 3.25 hours, the glaze slurry is aged for 12 hours.

[0031] Comparative Example 5 The method of Example 1 is followed, except that the S7 firing process is different. In S7, the glazed semi-finished product is placed in a roller kiln for firing, and the temperature is raised to 1250°C at a heating rate of 80°C / h and kept at this temperature for 14h, and then cooled to room temperature at a cooling rate of 60°C / h.

[0032] Test example The ceramic casserole prepared in the embodiment and the comparative example was subjected to performance testing. The impact toughness was tested in accordance with the provisions of GB / T14389-93, the glaze hardness was tested in accordance with the provisions of QB T4780-2015, the thermal shock resistance was tested in accordance with the provisions of QB / T2580-2018, the water absorption was tested in accordance with the provisions of GB / T3299-2011, the glossiness was tested in accordance with the provisions of GB / T3295-1996, the lead migration was tested in accordance with the provisions of GB31604.34-2016, and the cadmium migration was tested in accordance with the provisions of GB31604.24-2016. The test results are shown in Table 1 below: Table 1 Ceramic casserole performance test results

[0033] From the above, it can be seen that the heat-resistant ceramic casserole provided in Examples 1 to 3 of the present application has a high degree of matching between the ceramic body and glaze by optimizing the raw materials and content of the ceramic body and glaze. Under the preparation method provided in the present application, the obtained heat-resistant ceramic casserole has a retro matte appearance, good impact toughness and glaze hardness, good thermal stability, low water absorption and firing shrinkage, no lead and cadmium migration, and excellent comprehensive performance.

[0034] Combining Example 1 with Comparative Examples 1 and 2, in Comparative Example 1, where no andalusite was added to the green body formula, the ceramic casserole had reduced impact toughness and increased firing shrinkage. In Comparative Example 2, where no sepiolite was added to the green body formula, the ceramic casserole had reduced impact toughness and increased firing shrinkage, with the omission of sepiolite having a greater impact on the impact toughness and firing shrinkage of the ceramic casserole.

[0035] Combining Example 1 with Comparative Examples 3 and 4, the glaze in Comparative Example 3 lacks the addition of ZrSiO4@Al2O3. The ceramic casserole lacks the vintage matte finish and the retro feel of antique pottery. Its impact toughness is somewhat reduced, while its water absorption rate is increased. In Comparative Example 4, zirconium silicate and aluminum oxide are added directly to the glaze. This significantly reduces several properties of the ceramic casserole, including reduced impact toughness, hardness, and thermal shock resistance. The matte finish is less pronounced, and firing shrinkage is increased.

[0036] In combination with Example 1 and Comparative Example 5, the ceramic casserole prepared in Comparative Example 5 was directly fired at 1250°C, and the impact toughness, hardness and thermal shock resistance of the ceramic casserole were reduced, while the firing shrinkage and water absorption were increased.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or some technical features can be replaced by equivalents, which should all be included in the scope of the technical solutions requested for protection in this application.

Claims

1. A heat-resistant ceramic casserole, characterized in that: The invention is composed of a body and a glaze, wherein the body comprises the following raw materials in parts by weight: 30-35 parts of fused quartz, 8-10 parts of petalite, 9-11 parts of kaolin, 19-21 parts of washed illite clay, 5-7 parts of sepiolite, 5-6 parts of andalusite, 7-9 parts of coal gangue, 0.2-0.7 parts of gahnite, and 2-3 parts of talc; The glaze comprises the following raw materials in parts by weight: 18 to 20 parts of fused quartz, 14 to 16 parts of petalite, 12 to 14 parts of kaolin, 5 to 6 parts of calcium oxide, 1.5 to 2 parts of zinc oxide, 1 to 1.5 parts of strontium oxide, 8 to 10 parts of spodumene, 0.6 to 0.8 parts of lanthanum oxide, 8 to 10 parts of ZrSiO4@Al2O3 and 1.2 to 1.8 parts of colorant.

2. A heat-resistant ceramic casserole according to claim 1, characterized in that: In the green body, the fused quartz material is fused quartz material with different particle size distributions, including 35-40% of 20-60 mesh coarse particles and 60-65% of 80-120 mesh fine particles.

3. A heat-resistant ceramic casserole according to claim 1, characterized in that: In the glaze, the mesh number of fused quartz is 100 to 200 mesh.

4. A heat-resistant ceramic casserole according to claim 1, characterized in that: The colorant is obtained by mixing red iron oxide and black manganese oxide in a mass ratio of 1:0.15 to 0.

25.

5. The heat-resistant ceramic casserole according to claim 1, characterized in that: The preparation method of ZrSiO4@Al2O3 comprises the following steps: (1) D 50 Anhydrous ethanol is added to zirconium silicate with a size of 100 to 200 nm, with the mass volume ratio of zirconium silicate to ethanol being 1:30 to 50, and then polyvinyl pyrrolidone (1 to 2% by weight of the zirconium silicate) is added, and ultrasonic treatment is performed for 15 to 30 minutes to obtain a zirconium silicate dispersion. (2) AlCl3·6H2O was dissolved in ethanol to prepare an aluminum chloride solution with a concentration of 0.1-0.2 mol / L, ethanolamine was added in a molar ratio of aluminum chloride to ethanolamine of 1:1, and the mixture was stirred at 50-60°C for 1.5-2.5 hours to obtain an aluminum sol; (3) Add zirconium silicate dispersion to aluminum sol, control the molar ratio of zirconium silicate to aluminum chloride to be 1:0.05-0.4, ultrasonically treat the mixture for 15-30 minutes, heat the ultrasonically treated mixture to 60-70°C, slowly drop ammonia water into the mixture while stirring to adjust the pH to 8-9, let it stand for 12-24 hours, filter, dry at 75-85°C for 12-24 hours, heat to 450-500°C at a heating rate of 1-5°C / min, and calcine for 2-3 hours.

6. The heat-resistant ceramic casserole according to claim 1, characterized in that: The preparation method of the water-washed illite clay comprises the following steps: adding 200-mesh illite clay to water to prepare a slurry with a concentration of 20-30%, then adding 0.3-0.5% of water glass and 0.1-0.2% of hexametaphosphoric acid by weight of the illite clay, adjusting the pH to 8-9 with a sodium hydroxide solution, stirring at 300-500 rpm for 1-2 hours, filtering with a 200-mesh sieve, collecting the slurry under the sieve; and filtering the slurry under the sieve to a moisture content of 20-25%, and then standing it for 3-5 days for homogenization.

7. The method for preparing a heat-resistant ceramic casserole according to claim 1, characterized in that: The following steps are involved: S1. Weigh the raw materials of each billet according to the raw material ratio; S2. Add the raw materials of the blank except sepiolite into a rapid ball mill, add water according to the material, ball and water ratio of 1:1.5-2:0.4-0.45, use the rapid ball mill to ball mill the proportioned materials for 2.5-3.5 hours, then add sepiolite and continue ball milling for 0.5-1 hour to obtain a slurry; S3, the slurry after ball milling is aged for 2 to 5 days, and a vacuum clay machine is used for clay making, and the clay is poured into a gypsum mold for molding, and demolding is performed to obtain a wet blank; S4, drying the wet blank at room temperature for 10 to 12 hours for blanking, drying the wet blank at 50 to 90° C. for 24 to 48 hours, and blanking the dried blank again; S5. Weigh the other raw materials of the glaze except ZrSiO4@Al2O3 according to the formula, add them into a rapid ball mill, add water according to the material, ball and water ratio of 1:1.8-2.2:0.5-0.55, ball mill for 2-4 hours, then add ZrSiO4@Al2O3 and continue ball milling for 10-20 minutes. Aged for 12-24 hours to obtain a glaze slurry; S6. Place the green body on a wheelbarrow, pour the glaze slurry in the center of the green body, and use centrifugal force to evenly spread the glaze slurry on the surface of the green body, controlling the thickness of the glaze layer to 0.2-0.3 mm; S7. Place the glazed semi-finished product into a roller kiln for firing, and cool it down in the kiln.

8. The method for preparing a heat-resistant ceramic casserole according to claim 7, characterized in that: The weight ratio of S2 medium material, balls and water is 1:1.5:0.4, and the weight ratio of S5 medium material, balls and water is 1:2:0.

5.

9. The method for preparing a heat-resistant ceramic casserole according to claim 7, characterized in that: The sintering method is as follows: heating the temperature to 730-770°C at a heating rate of 60-100°C / h and keeping the temperature for 2-3h, heating the temperature to 1210-1290°C at a heating rate of 50-70°C / h and keeping the temperature for 13-15h, and then cooling the furnace to room temperature.

10. The method for preparing a heat-resistant ceramic casserole according to claim 9, characterized in that: The specific cooling with the furnace is to quickly cool down to 1010-1050℃ at a cooling rate of 100-120℃ / h, then keep warm for 10-20min, then slowly cool down to 400-450℃ at a cooling rate of 50-70℃ / h, and finally cool down to room temperature at a cooling rate of 70-90℃ / h.

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