Cracking-free Ru porcelain tableware and preparation method thereof

Abstract

The invention discloses cracking-free Ru porcelain tableware and a preparation method thereof, and belongs to the technical field of ceramic products, the cracking-free Ru porcelain tableware comprises a green body and glaze, the green body is prepared by pulping a blank material and the blank material and then adding alkali and water glass, and the blank material is prepared from the following components in parts by mass: 10-20 parts of potassium feldspar, 10-20 parts of quartz and 35-45 parts of half-slope soil. The glaze is prepared from the following components in parts by mass: 45 to 55 parts of feldspar, 15 to 20 parts of black stone, 10 to 15 parts of calcite, 10 to 20 parts of quartz, 1 to 3 parts of cattle bone powder and 3 to 5 parts of talc. The combination mechanism of the green body and the glaze is deeply researched, the formula system is optimized, and the cracking-free effect of the Ru porcelain tableware is ensured; on the basis of keeping the characteristics of the traditional incense ash blank, the formula structure of the blank is innovated; the anti-seepage performance and the practical function of the tableware product are comprehensively improved.

Description

Technical Field

[0001] This invention relates to the field of ceramic products technology, specifically to a crazing-free Ru porcelain tableware and its preparation method. Background Technology

[0002] Ru ware ranks first among the five famous porcelains of the Song Dynasty in my country, namely Ru, Guan, Jun, Ge, and Ding, and is named after its place of origin, the ancient Ruzhou. Ru ware began firing in the Tang Dynasty and flourished in the Northern Song Dynasty. Due to its typical characteristics of "sky-blue, jade-like surface, wing-like patterns, sparse morning star-like patterns, and sesame-seed-like glaze supports," it was designated as a tribute item by the Song imperial court and its use by commoners was strictly prohibited. Ru ware porcelain has a fine clay, a hard body, exquisite workmanship, and is fully glazed and fired on supports. The glaze contains agate, giving it a lustrous color, including egg white, sky blue, bean green, and azure, and is praised as "resembling jade but not jade, yet surpassing jade."

[0003] Ru ware, ranking first among the five famous porcelains of the Song Dynasty ("Ru, Guan, Jun, Ge, Ding"), is named after its place of origin, the ancient Ruzhou. Its production history began in the Tang Dynasty and reached its peak during the Northern Song Dynasty. Renowned for its characteristic "sky-blue glaze after rain, lustrous color, dense body, and unique crackle pattern," Ru ware was designated as a tribute item by the Song imperial court and strictly prohibited from circulation among the common people. The artistic characteristics of Ru ware are as follows: 1. The porcelain body is fine and dense, and the craftsmanship is exquisite; 2. It adopts a full-glaze firing technique, and agate components are incorporated into the glaze; 3. The glaze is warm and lustrous like jade, mainly in classic colors such as egg white, sky blue, bean green, and sky blue, presenting a unique texture that is "like jade but not jade, yet better than jade".

[0004] Traditional Ru ware is characterized by its cicada wing-like crackle pattern. While this decorative crackle pattern gives the object a unique aesthetic appeal, it has significant drawbacks in its actual use as tableware: the crackle structure results in poor glaze impermeability, and dirt easily accumulates in the gaps, affecting hygiene and safety. These drawbacks limit its application and development in the tableware field. Summary of the Invention

[0005] This invention provides a crazing-free Ru porcelain tableware and its preparation method. It conducts in-depth research on the bonding mechanism between the body and the glaze, optimizes the formula system, and ensures that the Ru porcelain tableware achieves a crazing-free effect. While retaining the characteristics of traditional incense ash body, it innovates the body formula structure and comprehensively improves the anti-seepage performance and practical function of the tableware products.

[0006] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows: A type of Ru ware tableware without crackle glaze includes a body and a glaze. The body is made from raw material and a slurry of raw material with the addition of alkali and water glass. The raw material is composed of the following components in parts by weight: 10-20 parts potassium feldspar, 10-20 parts quartz, 35-45 parts Banpo soil, and 25-35 parts Tanggou soil. The specific gravity of the raw material after slurry preparation is 1.65-1.68. The added alkali is 0.3-0.5% of the slurry mass, and the added water glass is 0.1-0.2% of the slurry mass. The glaze is composed of the following components in parts by weight: 45-55 parts feldspar, 15-20 parts black stone, 10-15 parts calcite, 10-20 parts quartz, 1-3 parts ox bone powder, and 3-5 parts talc.

[0007] The blank is composed of the following components in parts by weight: 15 parts potassium feldspar, 15 parts quartz, 40 parts Banpo soil, and 30 parts Tanggou soil; the glaze is composed of the following components in parts by weight: 50 parts feldspar, 17 parts black stone, 12 parts calcite, 15 parts quartz, 2 parts ox bone powder, and 4 parts talc.

[0008] The added alkali is sodium carbonate or sodium silicate.

[0009] This invention provides a method for preparing the above-mentioned crack-free Ru porcelain tableware, comprising the following steps: Step 1: Calculate by mass fraction, after sorting and bleaching, add potassium feldspar, quartz, Banpo soil and Tanggou soil into a ball mill, add water and grind for 15-20 hours, after iron removal by sieve, a slurry with a specific gravity of 1.65-1.68 is obtained; add 0.3-0.5% alkali and 0.1-0.2% water glass, and stir evenly; Step 2: Calculate by mass fraction and put the glaze materials feldspar, black stone, calcite, quartz, bone powder and talc into a ball mill. Add water and grind for 26-32 hours. Sieve to remove iron, and after sedimentation, remove excess water to obtain a glaze slurry without cracking. Adjust the glaze slurry to a specific gravity of 1.40-1.50 and set aside. Step 3: Pour the mud slurry obtained in Step 1 into the plaster mold, trim and attach the clay body, let it air dry naturally, and then put it into the kiln for bisque firing at a temperature of 850-950℃. Brush the bisque fired body with the glaze slurry prepared in Step 3 to obtain the glazed body. Step 4: Place the glazed blank prepared in Step 3 into the kiln and fire it according to the following temperature curve: (1) Oxidation and evaporation stage: The kiln door is slightly opened, and the temperature is raised to 105℃ at a rate of 1~2℃ / min. The temperature is held for 30-40min to reduce the moisture content of the billet to 10%-20% and prevent carbon deposition from causing the billet to collapse. (2) Oxidation stage: Heat to 580℃-900℃ at a rate of 1~2℃ / min, close the kiln door, reduce the ventilation in the kiln, and keep warm at 580℃-900℃ for 1~15h, then enter the flat firing and medium fire holding to reduce the overall temperature difference. (3) Weak reduction stage: Heat to 900-1100℃ at a rate of 0.3~0.8℃ / min, close the box slightly, maintain a 3-5% carbon monoxide atmosphere, keep warm for 2~2.5h, when the glaze becomes opaque, it will turn white when exposed to fire, and the heating should be slowed down. (4) Strong reduction stage: The temperature is increased to 900-1200℃ at a rate of 0.8~0.9℃ / min, the carbon monoxide atmosphere is controlled at 7-10%, and the temperature is maintained for 2-2.5h to reduce the ferric oxide in the glaze to ferrous oxide and vitrify the glaze surface. (5) High-temperature holding period: Heat to 1250-1350℃ at a rate of 0.8~0.9℃ / min, hold for 4-5 hours, slightly open the gate, and release gas steadily from the glaze to form crystals; (6) Cooling stage: rapidly cool to 800℃ at a rate of 10-12℃ / min, cool to 700℃ at a rate of 5-8℃ / min, cool to 400℃ at a rate of 1-2℃ / min, and cool to room temperature at a very slow rate of 0.5-1℃ / min. Remove and it is ready.

[0010] In step 1, the ratio of water to ball milling material to billet is 1:(2-2.5):1.

[0011] In step 2, the ratio of water to ball milling material to billet is 1:(1-1.2):1.

[0012] In step 4, the kiln is an elliptical semi-downdraft kiln, and the outer wall and sealing of the sagger are coated with a layer of refractory mud. Beneficial effects

[0013] This invention provides a crazing-free Ru porcelain tableware and its preparation method, which has the following beneficial effects: 1. The raw material of this invention adopts a potassium feldspar-quartz-Banpo soil-Tanggou soil system. By adding 0.3-0.5% alkali and 0.1-0.2% water glass, the density and impermeability of the raw material are significantly improved. The glaze of this invention adopts a feldspar-black stone-calcite-quartz-ox bone powder-talc composite glaze, which not only retains the unique jade-like texture of Ru ware, but also achieves a crackle-free structure.

[0014] 2. The present invention adopts a graded ball milling process: the raw material is ground for 15-20 hours (water:ball:material = 1:2-2.5:1), and the glaze is ground for 26-32 hours (water:ball:material = 1:1-1.2:1) to ensure that the raw materials are fully refined and mixed.

[0015] 3. This invention employs a six-stage firing temperature curve: the oxidation evaporation stage (holding at 105℃) effectively controls the moisture content; the oxidation stage (holding at 580-900℃) eliminates thermal stress; the weak reduction stage (900-1100℃) establishes the basis for glaze devitrification; the strong reduction stage (900-1200℃) achieves the Fe2O3→FeO conversion; the high-temperature holding period (1250-1350℃) promotes crystal development; and the four-stage cooling process avoids stress concentration on the glaze surface.

[0016] 4. This invention employs a four-stage cooling process, including a rapid cooling stage (above 800℃), where a rapid cooling rate of 10-12℃ / min is used to quickly reduce the reactor temperature through a high-efficiency heat exchange system, shortening the production cycle and preventing material performance degradation at high temperatures. The medium-speed cooling stage (700℃-800℃) adjusts the cooling rate to 5-8℃ / min, balancing efficiency and thermal stress control to ensure equipment structural stability and prevent mechanical damage caused by excessive temperature differences. The slow cooling stage (400℃-700℃) further reduces the temperature to 1-2℃ / min, focusing on eliminating residual thermal stress, ensuring uniform shrinkage of the reactor's inner wall and internal structure, and reducing the risk of cracking. The free cooling stage (below 400℃), after the temperature drops to 400℃, adopts an extremely slow cooling rate of 0.5-1℃ / min to ensure the material completes phase transformation equilibrium, ultimately achieving stable product performance.

[0017] 5. This invention fundamentally solves the problem of crackling in traditional Ru porcelain by optimizing the body-glaze ratio and controlling the firing process. The dense body-glaze structure makes the tableware suitable for holding various liquids, and the hygiene performance meets the food safety standards. While achieving crack-free operation, it still maintains the warm and smooth texture of Ru porcelain, which is "like jade but not jade". Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0019] This embodiment provides a crazing-free Ru porcelain tableware, comprising a body and a glaze. The body is made from raw material and a slurry containing sodium carbonate and water glass. The raw material is composed of the following components in parts by weight: 15 parts potassium feldspar, 15 parts quartz, 40 parts Banpo soil, and 30 parts Tanggou soil. The specific gravity of the raw material after slurry preparation is 1.67, with sodium carbonate added at 0.4% of the slurry mass and water glass added at 0.15% of the slurry mass. The glaze is composed of the following components in parts by weight: 50 parts feldspar, 17 parts black stone, 12 parts calcite, 15 parts quartz, 2 parts ox bone powder, and 4 parts talc.

[0020] The raw material is composed of the following components in parts by weight: 15 parts potassium feldspar, 15 parts quartz, 40 parts Banpo clay, and 30 parts Tanggou clay; the glaze is composed of the following components in parts by weight: This embodiment also provides a method for preparing the above-mentioned uncrackled Ru porcelain tableware, including the following steps: Step 1: Calculate by mass fraction, after sorting and bleaching, add potassium feldspar, quartz, Banpo soil and Tanggou soil into a ball mill, add water and grind for 18 hours in the ball mill, the water:ball stone:raw material ratio is 1:2.2:1, after iron removal by sieve, a slurry with a specific gravity of 1.67 is obtained; add 0.4% sodium carbonate and 0.15% water glass, and stir evenly; Step 2: Calculate by mass fraction and put the glaze materials feldspar, black stone, calcite, quartz, ox bone powder and talc into a ball mill. Add water and grind for 28 hours. The ratio of water:ball stone:body material is 1:1.1:1. Sieve to remove iron, and after sedimentation, remove excess water to obtain a glaze slurry without cracking. Adjust the glaze slurry to a specific gravity of 1.45 and set aside. Step 3: Pour the mud slurry obtained in Step 1 into the plaster mold, trim and attach the clay body, let it air dry naturally, and then put it into the kiln for bisque firing at 900℃. Brush the bisque fired body with the glaze slurry prepared in Step 3 to obtain the glazed body. The kiln is an elliptical semi-downdraft kiln, and the outer wall and sealing of the sagger are coated with a refractory mud layer. Step 4: Place the glazed blank prepared in Step 3 into the kiln and fire it according to the following temperature curve: (1) Oxidation and evaporation stage: The kiln door is slightly opened, and the temperature is raised to 105℃ at a rate of 1.5℃ / min and held for 35min to reduce the moisture content of the billet to 15% and prevent carbon deposition from causing the billet to collapse. (2) Oxidation stage: Heat up to 800℃ at a rate of 1.5℃ / min, close the kiln door, reduce the ventilation in the kiln, and keep it at 800℃ for 1~15h, then proceed to flat firing and medium fire holding to reduce the overall temperature difference; (3) Weak reduction stage: Heat to 1000℃ at a rate of 0.5℃ / min, close the box plate slightly, maintain a 4% carbon monoxide atmosphere, keep warm for 2.2h, when the glaze becomes opaque, it turns white when exposed to fire, and the heating is slowed down; (4) Strong reduction stage: The temperature is increased to 1100℃ at a rate of 0.8℃ / min, the carbon monoxide atmosphere is controlled at 8%, and the temperature is maintained for 2 hours to reduce the ferric oxide in the glaze to ferrous oxide and vitrify the glaze surface. (5) High-temperature holding period: The temperature is increased to 1300℃ at a rate of 0.8℃ / min and held for 4 hours. The gate is slightly opened and the glaze surface releases gas steadily, forming crystals.

[0021] (6) Cooling stage: rapidly cool to 800℃ at a rate of 11℃ / min, cool to 700℃ at a rate of 6℃ / min, cool to 400℃ at a rate of 1.5℃ / min, and cool to room temperature at an extremely slow rate of 0.8℃ / min. Remove and obtain. Example 2

[0022] This embodiment provides a crazing-free Ru porcelain tableware, comprising a body and a glaze. The body is made from raw material and a slurry containing sodium carbonate and water glass. The raw material is composed of the following components in parts by weight: 100 parts potassium feldspar, 20 parts quartz, 35 parts Banpo soil, and 35 parts Tanggou soil. The specific gravity of the raw material after slurry preparation is 1.65. The added sodium carbonate is 0.5% of the slurry mass, and the added water glass is 0.1% of the slurry mass. The glaze is composed of the following components in parts by weight: 45 parts feldspar, 20 parts black stone, 10 parts calcite, 20 parts quartz, 1 part ox bone powder, and 5 parts talc.

[0023] This embodiment also provides a method for preparing the above-mentioned uncrackled Ru porcelain tableware, including the following steps: Step 1: Calculate by weight, after sorting and bleaching, take the raw materials, and put potassium feldspar, quartz, Banpo soil and Tanggou soil into a ball mill. Add water to the ball mill and grind for 15 hours. The ratio of water:ball stone:raw material is 1:2.5:1. After iron removal by sieve, a slurry with a specific gravity of 1.65 is obtained. Add 0.5% sodium carbonate and 0.1% water glass and stir evenly. Step 2: Calculate by mass fraction and put the glaze materials feldspar, black stone, calcite, quartz, ox bone powder and talc into a ball mill. Add water and grind for 26 hours. The ratio of water:ball stone:body material is 1:1.2:1. Sieve to remove iron, and after sedimentation, remove excess water to obtain a glaze slurry without cracking. Adjust the glaze slurry to a specific gravity of 1.40 and set aside. Step 3: Pour the mud slurry obtained in Step 1 into the plaster mold, trim and attach the clay body, let it air dry naturally, and then put it into the kiln for bisque firing at a temperature of 850℃. Brush the bisque fired body with the glaze slurry prepared in Step 3 to obtain the glazed body. The kiln is an elliptical semi-downdraft kiln, and the outer wall and sealing of the sagger are coated with a refractory mud layer. Step 4: Place the glazed blank prepared in Step 3 into the kiln and fire it according to the following temperature curve: (1) Oxidation and evaporation stage: The kiln door is slightly opened, and the temperature is raised to 105℃ at a rate of 1℃ / min. The temperature is held for 30min to reduce the moisture content of the billet to 10% and prevent carbon deposition from causing the billet to collapse. (2) Oxidation stage: Heat up to 900℃ at a rate of 1℃ / min, close the kiln door, reduce the ventilation in the kiln, and keep it at 900℃ for 1 hour before entering the flat firing and medium fire holding stage to reduce the overall temperature difference. (3) Weak reduction stage: Heat to 1100℃ at a rate of 0.3℃ / min, close the box plate slightly, maintain a 3% carbon monoxide atmosphere, keep warm for 2.5h, when the glaze becomes opaque, it turns white when exposed to fire, and the heating is slowed down; (4) Strong reduction stage: The temperature is increased to 1200℃ at a rate of 0.8℃ / min, the carbon monoxide atmosphere is controlled at 7%, and the temperature is maintained for 2.5h to reduce the ferric oxide in the glaze to ferrous oxide and vitrify the glaze surface. (5) High-temperature holding period: The temperature is increased to 1350℃ at a rate of 0.8℃ / min and held for 4 hours. The gate is slightly opened and the glaze surface releases gas steadily, forming crystals.

[0024] (6) Cooling stage: rapidly cool to 800°C at a rate of 10°C / min, cool to 700°C at a rate of 8°C / min, cool to 400°C at a rate of 1°C / min, and cool to room temperature at a very slow rate of 1°C / min. Remove and it is ready. Example 3

[0025] This embodiment provides a crazing-free Ru porcelain tableware, comprising a body and a glaze. The body is made from raw material and a slurry containing sodium silicate and water glass. The raw material is composed of the following components in parts by weight: 20 parts potassium feldspar, 10 parts quartz, 45 parts Banpo soil, and 25 parts Tanggou soil. The specific gravity of the raw material after slurry preparation is 1.68. The added sodium silicate is 0.3% of the slurry mass, and the added water glass is 0.2% of the slurry mass. The glaze is composed of the following components in parts by weight: 55 parts feldspar, 15 parts black stone, 15 parts calcite, 10 parts quartz, 3 parts ox bone powder, and 3 parts talc.

[0026] This embodiment also provides a method for preparing the above-mentioned uncrackled Ru porcelain tableware, including the following steps: Step 1: Calculate by mass fraction, after sorting and bleaching, add potassium feldspar, quartz, Banpo soil and Tanggou soil into a ball mill, add water and grind for 20 hours in the ball mill, the water:ball stone:raw material ratio is 1:2:1, after iron removal by sieve, a slurry with a specific gravity of 1.68 is obtained; add 0.3% sodium silicate and 0.1% water glass, and stir evenly; Step 2: Calculate by mass fraction, take the glaze material feldspar, black stone, calcite, quartz, ox bone powder and talc and put them into a ball mill. Add water and grind for 32 hours. The ratio of water:ball stone:body material is 1:1:1. Sieve to remove iron, remove excess water after sedimentation, and obtain a glaze slurry without cracking. Adjust the glaze slurry to a specific gravity of 1.50 and set aside. Step 3: Pour the mud slurry obtained in Step 1 into the plaster mold, trim and attach the clay body, let it air dry naturally, and then put it into the kiln for bisque firing at a temperature of 950℃. Brush the bisque fired body with the glaze slurry prepared in Step 3 to obtain the glazed body. The kiln is an elliptical semi-downdraft kiln, and the outer wall and sealing of the sagger are coated with a refractory mud layer. Step 4: Place the glazed blank prepared in Step 3 into the kiln and fire it according to the following temperature curve: (1) Oxidation and evaporation stage: The kiln door is slightly opened, and the temperature is raised to 105℃ at a rate of 2℃ / min. The temperature is held for 30min to reduce the moisture content of the billet to 20% and prevent carbon deposition from causing the billet to collapse. (2) Oxidation stage: Heat up to 580℃ at a rate of 2℃ / min, close the kiln door, reduce the ventilation in the kiln, and keep it at 580℃ for 15 hours before entering the flat firing and medium fire holding stage to reduce the overall temperature difference. (3) Weak reduction stage: Heat to 900℃ at a rate of 0.8℃ / min, close the box plate slightly, maintain a 3% carbon monoxide atmosphere, keep warm for 2.5h, when the glaze becomes opaque, it turns white when exposed to fire, and the heating is slowed down; (4) Strong reduction stage: The temperature is increased to 1200℃ at a rate of 0.9℃ / min, the carbon monoxide atmosphere is controlled at 7%, and the temperature is maintained for 2.5h to reduce the ferric oxide in the glaze to ferrous oxide and vitrify the glaze surface. (5) High-temperature holding period: The temperature is increased to 1250℃ at a rate of 0.9℃ / min and held for 5 hours. The gate is slightly opened and the glaze surface releases gas steadily, forming crystals.

[0027] (6) Cooling stage: rapidly cool to 800℃ at a rate of 12℃ / min, cool to 700℃ at a rate of 5℃ / min, cool to 400℃ at a rate of 2℃ / min, and cool to room temperature at an extremely slow rate of 0.5℃ / min. Remove and obtain. Example 4

[0028] This embodiment provides a crazing-free Ru porcelain tableware, comprising a body and a glaze. The body is made from raw material and a slurry containing sodium silicate and water glass. The raw material is composed of the following components in parts by weight: 18 parts potassium feldspar, 12 parts quartz, 42 parts Banpo soil, and 28 parts Tanggou soil. The specific gravity of the raw material after slurry preparation is 1.66. The added sodium silicate accounts for 0.45% of the slurry mass, and the added water glass accounts for 0.12% of the slurry mass. The glaze is composed of the following components in parts by weight: 48 parts feldspar, 16 parts black stone, 14 parts calcite, 12 parts quartz, 2 parts ox bone powder, and 4 parts talc.

[0029] This embodiment also provides a method for preparing the above-mentioned crazing-free Ru porcelain tableware, including the following steps: Step 1: Calculate by weight, after sorting and bleaching, add potassium feldspar, quartz, Banpo soil and Tanggou soil to a ball mill, add water and grind for 15 hours. The ratio of water:ball stone:raw material is 1:2.3:1. After iron removal by sieve, a slurry with a specific gravity of 1.66 is obtained. Add 0.45% sodium silicate and 0.12% water glass and stir evenly. Step 2: Calculate by weight parts and put the glaze materials feldspar, black stone, calcite, quartz, ox bone powder and talc into a ball mill. Add water and grind for 28 hours. The ratio of water:ball stone:body material is 1:1.15:1. Sieve to remove iron, and after sedimentation, remove excess water to obtain a glaze slurry without cracking. Adjust the glaze slurry to a specific gravity of 1.40-1.50 and set aside. Step 3: Pour the mud slurry obtained in Step 1 into the plaster mold, trim and bond the clay body, let it air dry naturally, and then put it into the kiln for bisque firing at a temperature of 860℃. Brush the bisque fired body with the glaze slurry prepared in Step 3 to obtain the glazed body. The kiln is an elliptical semi-downdraft kiln, and the outer wall and sealing of the sagger are coated with a refractory mud layer. Step 4: Place the glazed blank prepared in Step 3 into the kiln and fire it according to the following temperature curve: (1) Oxidation and evaporation stage: The kiln door is slightly opened, and the temperature is raised to 105℃ at a rate of 1℃ / min. The temperature is held for 35min to reduce the moisture content of the billet to 10%-20% and prevent carbon deposition from causing the billet to collapse. (2) Oxidation stage: Heat up to 850℃ at a rate of 2℃ / min, close the kiln door, reduce the ventilation in the kiln, and keep warm at 850℃ for 12 hours before entering the flat firing and medium fire holding stage to reduce the overall temperature difference. (3) Weak reduction stage: Heat to 1050℃ at a rate of 0.6℃ / min, close the box plate slightly, maintain a 4% carbon monoxide atmosphere, keep warm for 2 hours, when the glaze becomes opaque, it turns white when exposed to fire, and the heating is slowed down; (4) Strong reduction stage: The temperature is increased to 1100℃ at a rate of 0.8℃ / min, the carbon monoxide atmosphere is controlled at 8%, and the temperature is maintained for 2.2h to reduce the ferric oxide in the glaze to ferrous oxide and vitrify the glaze surface. (5) High-temperature holding period: The temperature is increased to 1300℃ at a rate of 0.8℃ / min and held for 4 hours. The gate is slightly opened and the glaze surface releases gas steadily, forming crystals.

[0030] (6) Cooling stage: rapidly cool to 800°C at a rate of 10°C / min, cool to 700°C at a rate of 7°C / min, cool to 400°C at a rate of 1°C / min, and cool to room temperature at a very slow rate of 1°C / min. Remove and it is ready.

[0031] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A type of Ru ware tableware without crackle glaze, comprising a body and a glaze, characterized in that: The blank is made from raw material and raw material slurry with the addition of alkali and water glass. The raw material is composed of the following components in parts by weight: 10-20 parts potassium feldspar, 10-20 parts quartz, 35-45 parts Banpo soil, and 25-35 parts Tanggou soil. The specific gravity of the raw material after slurry preparation is 1.65-1.

68. The added alkali is 0.3-0.5% of the slurry mass, and the added water glass is 0.1-0.2% of the slurry mass. The glaze is composed of the following components in parts by weight: 45-55 parts feldspar, 15-20 parts black stone, 10-15 parts calcite, 10-20 parts quartz, 1-3 parts bone powder, and 3-5 parts talc.

2. The Ru porcelain tableware without crackle glaze according to claim 1, characterized in that: The blank is composed of the following components in parts by weight: 15 parts potassium feldspar, 15 parts quartz, 40 parts Banpo soil, and 30 parts Tanggou soil; the glaze is composed of the following components in parts by weight: 50 parts feldspar, 17 parts black stone, 12 parts calcite, 15 parts quartz, 2 parts ox bone powder, and 4 parts talc.

3. The Ru porcelain tableware without crackle glaze according to claim 1, characterized in that: The added alkali is sodium carbonate or sodium silicate.

4. A method for preparing a crazing-free Ru porcelain tableware according to any one of claims 1-3, characterized in that... Includes the following steps: Step 1: Calculate by mass fraction, after sorting and bleaching, add potassium feldspar, quartz, Banpo soil and Tanggou soil into a ball mill, add water and grind for 15-20 hours, after iron removal by sieve, a slurry with a specific gravity of 1.65-1.68 is obtained; add 0.3-0.5% alkali and 0.1-0.2% water glass, and stir evenly; Step 2: Calculate by mass fraction and put the glaze materials feldspar, black stone, calcite, quartz, bone powder and talc into a ball mill. Add water and grind for 26-32 hours. Sieve to remove iron, and after sedimentation, remove excess water to obtain a glaze slurry without cracking. Adjust the glaze slurry to a specific gravity of 1.40-1.50 and set aside. Step 3: Pour the mud slurry obtained in Step 1 into the plaster mold, trim and attach the clay body, let it air dry naturally, and then put it into the kiln for bisque firing at a temperature of 850-950℃. Brush the bisque fired body with the glaze slurry prepared in Step 3 to obtain the glazed body. Step 4: Place the glazed blank prepared in Step 3 into the kiln and fire it according to the following temperature curve: (1) Oxidation and evaporation stage: The kiln door is slightly opened, and the temperature is raised to 105℃ at a rate of 1~2℃ / min. The temperature is held for 30-40min to reduce the moisture content of the billet to 10%-20% and prevent carbon deposition from causing the billet to collapse. (2) Oxidation stage: Heat to 580℃-900℃ at a rate of 1~2℃ / min, close the kiln door, reduce the ventilation in the kiln, and keep warm at 580℃-900℃ for 1~15h, then enter the flat firing and medium fire holding to reduce the overall temperature difference. (3) Weak reduction stage: Heat to 900-1100℃ at a rate of 0.3~0.8℃ / min, close the box slightly, maintain a 3-5% carbon monoxide atmosphere, keep warm for 2~2.5h, when the glaze becomes opaque, it will turn white when exposed to fire, and the heating should be slowed down. (4) Strong reduction stage: The temperature is increased to 900-1200℃ at a rate of 0.8~0.9℃ / min, the carbon monoxide atmosphere is controlled at 7-10%, and the temperature is maintained for 2-2.5h to reduce the ferric oxide in the glaze to ferrous oxide and vitrify the glaze surface. (5) High-temperature holding period: Heat to 1250-1350℃ at a rate of 0.8~0.9℃ / min, hold for 4-5 hours, slightly open the gate, and release gas steadily from the glaze to form crystals; (6) Cooling stage: rapidly cool to 800℃ at a rate of 10-12℃ / min, cool to 700℃ at a rate of 5-8℃ / min, cool to 400℃ at a rate of 1-2℃ / min, and cool to room temperature at a very slow rate of 0.5-1℃ / min. Remove and it is ready.

5. The method for preparing a crazing-free Ru porcelain tableware according to claim 4, characterized in that: In step 1, the ratio of water to ball milling material to billet is 1:(2-2.5):

1.

6. The method for preparing a crazing-free Ru porcelain tableware according to claim 4, characterized in that: In step 2, the ratio of water to ball milling material to billet is 1:(1-1.2):

1.

7. The method for preparing a crazing-free Ru porcelain tableware according to claim 4, characterized in that: In step 4, the kiln is an elliptical semi-downdraft kiln, and the outer wall and sealing of the sagger are coated with a layer of refractory mud.