Lithium low-expansion ceramic pot suitable for induction cooker and preparation method of lithium low-expansion ceramic pot

Abstract

The invention relates to the technical field of ceramic pots, in particular to a lithium low-expansion ceramic pot suitable for an induction cooker and a preparation method of the lithium low-expansion ceramic pot. The ceramic pot green body comprises the following components in percentage by mass: 35-45% of spodumene, 5-10% of petalite, 20-30% of kaolin, 15-20% of red soil, 4-10% of quartz, 5-10% of aluminum oxide and 1-3% of magnesium oxide; the glaze is prepared from the following components: 20 to 30 percent of spodumene, 8 to 15 percent of petalite, 15 to 25 percent of kaolin, 10 to 25 percent of leaf feldspar, 10 to 15 percent of quartz, 5 to 8 percent of calcite, 4 to 7 percent of ferric oxide, 3 to 5 percent of manganese oxide and 2 to 3 percent of zinc oxide; the magnetic conductive film comprises the following components: 10-30% of glass powder and 70-90% of iron powder.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic pots, in particular to a lithium low-expansion ceramic pot suitable for an electromagnetic oven and a preparation method thereof. BACKGROUND

[0002] In recent years, with the sustained development of China's economy, people's living standards have been continuously improved, so the demand for ceramic pots, such as "green health cookware", has increased greatly. However, the current ceramic pots on the market have low thermal shock resistance, most of which can only withstand 450-20℃ heat exchange once without cracking, and only a few manufacturers can produce 600-20℃ heat exchange once without cracking. There is no product that can be directly used on an electromagnetic oven. Therefore, it is urgent to develop and produce ceramic pots with better thermal shock resistance and capable of being used on an electromagnetic oven. SUMMARY

[0003] The present application aims to provide a lithium low-expansion ceramic pot suitable for an electromagnetic oven and a preparation method thereof, solving the technical problem that there is no product that can be directly used on an electromagnetic oven in the prior art.

[0004] The present application discloses a lithium low-expansion ceramic pot suitable for an electromagnetic oven, comprising a ceramic pot blank, glaze and a magnetic film. The composition of the ceramic pot blank includes, in mass percentage, 35-45% of spodumene, 5-10% of petalite, 20-30% of kaolin, 15-20% of red clay, 4-10% of quartz, 5-10% of alumina and 1-3% of magnesium oxide; The composition of the glaze includes 20-30% of spodumene, 8-15% of petalite, 15-25% of kaolin, 10-25% of leaf feldspar, 10-15% of quartz, 5-8% of calcite, 4-7% of ferric oxide, 3-5% of manganese oxide and 2-3% of zinc oxide; The composition of the magnetic film includes 10-30% of glass powder and 70-90% of iron powder.

[0005] A preparation method of a lithium low-expansion ceramic pot suitable for an electromagnetic oven, comprising the following steps: S1. Ball milling spodumene, petalite, kaolin, red clay, quartz, alumina and magnesium oxide; S2. Sintering after pressing the raw materials to form a ceramic pot blank; S3. Ball milling spodumene, petalite, kaolin, leaf feldspar, quartz, calcite, ferric oxide, manganese oxide and zinc oxide to obtain glaze; S4. Immersing the ceramic pot blank obtained in step S2 in the glaze obtained in step S3 to form a glaze on the ceramic pot blank; S5. Sinter the glazed ceramic pot to obtain a glazed ceramic pot; S6. Apply a magnetic film slurry to the bottom of the glazed ceramic pot, dry it, and sinter it in a nitrogen atmosphere to obtain a finished ceramic pot.

[0006] Further, the ball milling uses deionized water and zirconia balls as solvent and ball milling medium, and the ball milling time is 8-24h.

[0007] Further, the mass ratio of the material, water, and balls during the ball milling is 1:1.5:3, and the rotation speed is 150r / min.

[0008] Further, a dispersant and a binder are added to the ball-milled raw materials in step S3 for re-ball milling.

[0009] Further, the dispersant is polyacrylammonium, and the addition amount is 1%-1.5% of the mass of the slurry; the binder is PVA, and the addition amount is 2%-3% of the mass of the slurry.

[0010] Further, the re-ball milling time is 2-4h.

[0011] Further, the ball-milled raw materials are sieved and dried before being kneaded in step S1.

[0012] Further, the drying is to dry the slurry to a water content of 19%-23%, and the kneading time is 8-24h.

[0013] Further, the concentration of the glaze in step S3 is controlled to be 45%-50%.

[0014] Further, the kneaded mud is shaped and dried in the shade.

[0015] Further, the water content of the shaped body is controlled to be 5%-6.5%.

[0016] Further, the sintering temperature of the sintering after the raw material is pressed and shaped is 1280℃-1320℃, and the holding time is 1h.

[0017] Further, the sintering schedule of the sintering after the raw material is pressed and shaped is 2℃ / min to 200℃, holding for 1h; 3℃ / min to 500℃, holding for 2h; and 2℃ / min to 1320℃, holding for 1h.

[0018] Further, the sintering temperature of the sintering of the glazed ceramic pot is 1100℃-1200℃, and the holding time is 4h.

[0019] Furthermore, the sintering regime for the glazed ceramic pot is as follows: heating at 2℃ / min to 200℃ and holding for 1 hour, heating at 2℃ / min to 500℃ and holding for 1 hour, and heating at 5℃ / min to 1200℃ and holding for 4 hours.

[0020] Furthermore, the magnetic conductive film slurry is prepared using glass powder, iron powder, mixed solvent, dispersant, binder and silane coupling agent.

[0021] Furthermore, the dispersant used in the magnetic conductive film slurry is ethyl acetate, added at 5-6% of the slurry mass; the binder is ethyl cellulose, added at 3-6% of the slurry mass; and the silane coupling agent is added at 3-5% of the slurry mass.

[0022] Furthermore, the solvent of the mixture is a mixture of ethanol and n-butanol.

[0023] Furthermore, the coating thickness of the magnetic conductive film is controlled at 2-5 mm, and after drying, it is sintered at 1000℃-1100℃ under a nitrogen atmosphere for 1 hour.

[0024] Furthermore, the sintering process after drying under a nitrogen atmosphere involves heating at 2°C / min to 200°C and holding for 1 hour, followed by heating at 5°C / min to the target temperature and holding for 1 hour.

[0025] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention reduces the amount of spodumene by introducing petalite and synthetic cordierite, thereby reducing the thermal expansion coefficient of the ceramic pot and improving its thermal shock resistance, enabling it to withstand a single water quenching at 800-20℃ without cracking. 2. This invention develops a magnetic film formula that enables ceramic pots to be used on induction cookers.

[0026] 3. By sintering iron powder at high temperature to form a network, eddy currents are generated inside the network under the influence of the magnetic field on the induction cooker, thus heating the ceramic pot on the induction cooker. The sintering and fusion of glass powder at high temperature achieves a tight bond between the magnetic conductive film and the ceramic pot. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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.

[0028] Example 1 This embodiment discloses a lithium-based low-expansion ceramic cooker suitable for induction cookers and its preparation method, including the following steps: Step 1: According to the formula ratio, weigh 700g spodumene, 200g petalite, 500g kaolin, 300g laterite, 100g quartz, 160g alumina, and 40g magnesium oxide, put them into a zirconia ball mill jar, add 6000g zirconia balls and 3000g deionized water, and ball mill on a horizontal ball mill for 12 hours at a speed of 150r / min; Step 2: After ball milling, the raw material is passed through a 100-mesh sieve and placed in a drying oven at 100℃ to dry to a moisture content of 19%-23%. Then, it is placed in a vacuum plow and plowed for 12 hours. Step 3: Press the clay into shape and let it air dry in a cool place until the moisture content is 5%-6.5%; Step 4: Place the dried blank into a sintering furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour, heat it to 500℃ at 3℃ / min and hold for 2 hours; heat it to 1280℃ at 2℃ / min and hold for 1 hour to obtain a ceramic pot bisque. Step 5: Weigh 200g spodumene, 150g lepidolite, 150g kaolinite, 210g feldspar, 100g quartz, 80g calcite, 40g ferric oxide, 50g manganese oxide and 20g zinc oxide and put them into a zirconia ball mill jar. Add 3000g zirconia grinding balls and 1000g deionized water. Ball mill on a horizontal ball mill for 8 hours at a speed of 150r / min. Step 6: Pass the ball-milled slurry through a 200-mesh sieve, add 20g of ammonium polyacrylate and 40g of PVA, ball-mill for 4 hours, then immerse the bisque obtained in Step 4 into the glaze to form a glaze on the surface of the body, and place it in a cool place to dry. Step 7: Place the glazed ceramic pot into a sintering furnace, raise the temperature to 200℃ at 2℃ / min and hold for 1 hour, raise the temperature to 500℃ at 2℃ / min and hold for 1 hour, raise the temperature to 1200℃ at 5℃ / min and hold for 4 hours to obtain a black glazed ceramic pot.

[0029] Step 8: Weigh 10g glass powder, 90g iron powder, 10g ethyl acetate, 6g ethyl cellulose, and 6g silane coupling agent. Add 150ml ethanol and 50ml n-butanol, stir for 1 hour, and evenly coat the bottom of the black glazed ceramic pot obtained in Step 7 with a coating thickness of 2.5mm. Allow to air dry.

[0030] Step 9: Place the ceramic pot in an atmosphere furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour under a nitrogen atmosphere, then heat it to 1100℃ at 5℃ / min and hold for 1 hour to obtain the finished ceramic pot.

[0031] Example 2 Step 1: According to the formula ratio, weigh out 774g spodumene, 154g petalite, 480g kaolin, 340g laterite, 86g quartz, 132g alumina, and 30g magnesium oxide, put them into a zirconia ball mill jar, add 6000g zirconia balls and 3000g deionized water, and ball mill on a horizontal ball mill for 12 hours at a speed of 150r / min; Step 2: After ball milling, the raw material is passed through a 100-mesh sieve and placed in a drying oven at 100℃ to dry to a moisture content of 19%-23%. Then, it is placed in a vacuum plow and plowed for 12 hours. Step 3: Press the clay into shape and let it air dry in a cool place until the moisture content is 5%-6.5%; Step 4: Place the dried blank into a sintering furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour, heat it to 500℃ at 3℃ / min and hold for 2 hours; heat it to 1290℃ at 2℃ / min and hold for 1 hour to obtain a ceramic pot bisque. Step 5: Weigh 220g spodumene, 130g petalite, 170g kaolin, 200g feldspar, 110g quartz, 80g calcite, 45g ferric oxide, 45g manganese oxide and 20g zinc oxide and put them into a zirconia ball mill jar. Add 3000g zirconia grinding balls and 1000g deionized water. Ball mill on a horizontal ball mill for 8 hours at a speed of 150r / min. Step 6: Pass the ball-milled slurry through a 200-mesh sieve, add 20g of ammonium polyacrylate and 40g of PVA, ball-mill for 4 hours, then immerse the bisque obtained in Step 4 into the glaze to form a glaze on the surface of the body, and place it in a cool place to dry. Step 7: Place the glazed ceramic pot into a sintering furnace, raise the temperature to 200℃ at 2℃ / min and hold for 1 hour, raise the temperature to 500℃ at 2℃ / min and hold for 1 hour, raise the temperature to 1200℃ at 5℃ / min and hold for 4 hours to obtain a black glazed ceramic pot.

[0032] Step 8: Weigh 15g glass powder, 85g iron powder, 12g ethyl acetate, 7g ethyl cellulose, and 7g silane coupling agent. Add 150ml ethanol and 50ml n-butanol, stir for 1 hour, and evenly coat the bottom of the black glazed ceramic pot obtained in Step 7 to a thickness of 3mm. Allow it to air dry.

[0033] Step 9: Place the ceramic pot in an atmosphere furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour under a nitrogen atmosphere, then heat it to 1100℃ at 5℃ / min and hold for 1 hour to obtain the finished ceramic pot.

[0034] Example 3 Step 1: According to the formula ratio, weigh 800g spodumene, 140g petalite, 500g kaolin, 300g laterite, 100g quartz, 100g alumina, and 60g magnesium oxide, put them into a zirconia ball mill jar, add 6000g zirconia balls and 3000g deionized water, and ball mill on a horizontal ball mill for 12 hours at a speed of 150r / min; Step 2: After ball milling, the raw material is passed through a 100-mesh sieve and placed in a drying oven at 100℃ to dry to a moisture content of 19%-23%. Then, it is placed in a vacuum plow and plowed for 12 hours. Step 3: Press the clay into shape and let it air dry in a cool place until the moisture content is 5%-6.5%; Step 4: Place the dried blank into a sintering furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour, heat it to 500℃ at 3℃ / min and hold for 2 hours; heat it to 1300℃ at 2℃ / min and hold for 1 hour to obtain a ceramic pot bisque. Step 5: Weigh 250g spodumene, 100g petalite, 200g kaolin, 160g feldspar, 120g quartz, 60g calcite, 50g ferric oxide, 40g manganese oxide and 20g zinc oxide and put them into a zirconia ball mill jar. Add 3000g zirconia grinding balls and 1000g deionized water. Ball mill on a horizontal ball mill for 8 hours at a speed of 150r / min. Step 6: Pass the ball-milled slurry through a 200-mesh sieve, add 20g of ammonium polyacrylate and 40g of PVA, ball-mill for 4 hours, then immerse the bisque obtained in Step 4 into the glaze to form a glaze on the surface of the body, and place it in a cool place to dry. Step 7: Place the glazed ceramic pot into a sintering furnace, raise the temperature to 200℃ at 2℃ / min and hold for 1 hour, raise the temperature to 500℃ at 2℃ / min and hold for 1 hour, raise the temperature to 1200℃ at 5℃ / min and hold for 4 hours to obtain a black glazed ceramic pot.

[0035] Step 8: Weigh 20g glass powder, 80g iron powder, 10g ethyl acetate, 8g ethyl cellulose, and 8g silane coupling agent. Add 150ml ethanol and 50ml n-butanol, stir for 1 hour, and evenly coat the bottom of the black glazed ceramic pot obtained in Step 7 with a coating thickness of 3.5mm. Allow to air dry.

[0036] Step 9: Place the ceramic pot in an atmosphere furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour under a nitrogen atmosphere, then heat it to 1100℃ at 5℃ / min and hold for 1 hour to obtain the finished ceramic pot.

[0037] Example 4 Step 1: According to the formula ratio, weigh 850g spodumene, 110g petalite, 480g kaolin, 320g laterite, 80g quartz, 130g alumina, and 30g magnesium oxide, put them into a zirconia ball mill jar, add 6000g zirconia balls and 3000g deionized water, and ball mill on a horizontal ball mill for 12 hours at a speed of 150r / min; Step 2: After ball milling, the raw material is passed through a 100-mesh sieve and placed in a drying oven at 100℃ to dry to a moisture content of 19%-23%. Then, it is placed in a vacuum plow and plowed for 12 hours. Step 3: Press the clay into shape and let it air dry in a cool place until the moisture content is 5%-6.5%; Step 4: Place the dried blank into a sintering furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour, heat it to 500℃ at 3℃ / min and hold for 2 hours; heat it to 1310℃ at 2℃ / min and hold for 1 hour to obtain a ceramic pot bisque fired blank. Step 5: Weigh 280g spodumene, 80g petalite, 220g kaolin, 100g feldspar, 150g quartz, 50g calcite, 60g ferric oxide, 30g manganese oxide and 30g zinc oxide and put them into a zirconia ball mill jar. Add 3000g zirconia grinding balls and 1000g deionized water. Ball mill on a horizontal ball mill for 8 hours at a speed of 150r / min. Step 6: Pass the ball-milled slurry through a 200-mesh sieve, add 20g of ammonium polyacrylate and 40g of PVA, ball-mill for 4 hours, then immerse the bisque obtained in Step 4 into the glaze to form a glaze on the surface of the body, and place it in a cool place to dry. Step 7: Place the glazed ceramic pot into a sintering furnace, raise the temperature to 200℃ at 2℃ / min and hold for 1 hour, raise the temperature to 500℃ at 2℃ / min and hold for 1 hour, raise the temperature to 1200℃ at 5℃ / min and hold for 4 hours to obtain a black glazed ceramic pot.

[0038] Step 8: Weigh 25g glass powder, 75g iron powder, 12g ethyl acetate, 9g ethyl cellulose, and 9g silane coupling agent. Add 150ml ethanol and 50ml n-butanol, stir for 1 hour, and evenly coat the bottom of the black glazed ceramic pot obtained in Step 7 with a coating thickness of 4mm. Allow it to air dry.

[0039] Step 9: Place the ceramic pot in an atmosphere furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour under a nitrogen atmosphere, then heat it to 1100℃ at 5℃ / min and hold for 1 hour to obtain the finished ceramic pot.

[0040] Example 5 Step 1: According to the formula ratio, weigh 900g spodumene, 100g petalite, 400g kaolin, 340g laterite, 80g quartz, 130g alumina, and 50g magnesium oxide, put them into a zirconia ball mill jar, add 6000g zirconia balls and 3000g deionized water, and ball mill on a horizontal ball mill for 12 hours at a speed of 150r / min; Step 2: After ball milling, the raw material is passed through a 100-mesh sieve and placed in a drying oven at 100℃ to dry to a moisture content of 19%-23%. Then, it is placed in a vacuum plow and plowed for 12 hours. Step 3: Press the clay into shape and let it air dry in a cool place until the moisture content is 5%-6.5%; Step 4: Place the dried blank into a sintering furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour, heat it to 500℃ at 3℃ / min and hold for 2 hours; heat it to 1320℃ at 2℃ / min and hold for 1 hour to obtain a ceramic pot bisque. Step 5: Weigh 300g spodumene, 80g lepidolite, 190g kaolin, 100g feldspar, 130g quartz, 70g calcite, 70g ferric oxide, 30g manganese oxide and 30g zinc oxide and put them into a zirconia ball mill jar. Add 3000g zirconia grinding balls and 1000g deionized water. Ball mill on a horizontal ball mill for 8 hours at a speed of 150r / min. Step 6: Pass the ball-milled slurry through a 200-mesh sieve, add 20g of ammonium polyacrylate and 40g of PVA, ball-mill for 4 hours, then immerse the bisque obtained in Step 4 into the glaze to form a glaze on the surface of the body, and place it in a cool place to dry. Step 7: Place the glazed ceramic pot into a sintering furnace, raise the temperature to 200℃ at 2℃ / min and hold for 1 hour, raise the temperature to 500℃ at 2℃ / min and hold for 1 hour, raise the temperature to 1200℃ at 5℃ / min and hold for 4 hours to obtain a black glazed ceramic pot.

[0041] Step 8: Weigh 30g glass powder, 70g iron powder, 12g ethyl acetate, 15g ethyl cellulose, and 15g silane coupling agent. Add 150ml ethanol and 50ml n-butanol, stir for 1 hour, and evenly coat the bottom of the black glazed ceramic pot obtained in Step 7 with a coating thickness of 4.5mm. Allow to air dry.

[0042] Step 9: Place the ceramic pot in an atmosphere furnace, heat it to 200℃ at 2℃ / min and hold for 1 hour under a nitrogen atmosphere, then heat it to 1100℃ at 5℃ / min and hold for 1 hour to obtain the finished ceramic pot.

[0043] Comparative Example 1 The only change from Example 1 is that in step 1, 700g of spodumene, 0g of petalite, 570g of kaolin, 380g of laterite, 150g of quartz, 160g of alumina, and 40g of magnesium oxide are weighed.

[0044] Comparative Example 2 The only change from Example 1 is that in step 1, 700g of spodumene, 200g of petalite, 520g of kaolinite, 320g of laterite, 100g of quartz, 160g of alumina, and 0g of magnesium oxide are weighed.

[0045] Comparative Example 3 The only change from Example 1 is that in step 1, 700g of spodumene, 80g of petalite, 550g of kaolin, 350g of laterite, 150g of quartz, 160g of alumina, and 10g of magnesium oxide are weighed.

[0046] Test case Table 1 Performance indicators of the ceramic pot in the embodiments of the present invention

[0047] As can be seen from Table 1, the coefficients of thermal expansion of all the embodiments are less than 0.8 × 10⁻⁶. -6 The ceramic pot did not crack after being rapidly cooled from 800 to 200℃, indicating that the thermal expansion coefficient of the ceramic pot was reduced and its thermal shock resistance was improved by introducing petalite and synthetic cordierite.

[0048] In Comparative Example 1, without the addition of petalite, the coefficient of thermal expansion increased to 1.32 × 10⁻⁶. -6 The thermal stability also decreased to 600-200℃ without cracking after a rapid cooling, indicating that adding petalite can improve the performance of the ceramic cookware. In Comparative Example 2, without the addition of magnesium oxide, the coefficient of thermal expansion increased to 1.13×10⁻⁶. -6 The thermal stability also decreased to 600-200℃ without cracking after a single rapid cooling, indicating that synthetic cordierite can improve the performance of ceramic cookware. In Comparative Example 3, the amounts of petalite and magnesium oxide were outside the optimal range, and the coefficient of thermal expansion increased to 1.05×10. -6 The thermal stability also decreased to 600-200℃ without cracking after a single rapid cooling, indicating that adding petalite and magnesium oxide outside the optimal range will reduce the performance of the ceramic pot.

[0049] The above are the embodiments listed in this example. However, this example is not limited to the optional embodiments described above. Those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments. Anyone can derive other various forms of embodiments based on the inspiration of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example. The scope of protection of this example should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A lithium-based low-expansion ceramic cooker suitable for induction cookers, characterized in that: Including the ceramic pot body, glaze, and magnetic film; The ceramic pot body, by weight percentage, comprises: 35-45% spodumene, 5-10% petalite, 20-30% kaolin, 15-20% laterite, 4-10% quartz, 5-10% alumina, and 1-3% magnesium oxide; The glaze composition includes: 20-30% spodumene, 8-15% lepidolite, 15-25% kaolinite, 10-25% feldspar, 10-15% quartz, 5-8% calcite, 4-7% ferric oxide, 3-5% manganese oxide, and 2-3% zinc oxide; The magnetic conductive film consists of 10-30% glass powder and 70-90% iron powder.

2. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 1, characterized in that: Includes the following steps: S1. Spodumene, petalite, kaolin, laterite, quartz, alumina and magnesium oxide are ball-milled; S2. Press the raw material into shape and then sinter it to obtain a ceramic pot blank; S3. A glaze is prepared by ball milling spodumene, petalite, kaolin, feldspar, quartz, calcite, ferric oxide, manganese oxide and zinc oxide. S4. Immerse the ceramic pot blank obtained in step S2 into the glaze obtained in step S3 to form a glaze surface on the ceramic pot blank. S5. Sinter the glazed ceramic pot to obtain a glazed ceramic pot; S6. A magnetic conductive film slurry is coated on the bottom of the glazed ceramic pot, dried, and then sintered under a nitrogen atmosphere to obtain the finished ceramic pot.

3. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 2, characterized in that: The ball milling process uses deionized water and zirconia balls as the solvent and milling medium, and the milling time is 8-24 hours.

4. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 2, characterized in that: The mass ratio of material:water:balls in the ball mill is 1:1.5:3, and the rotation speed is 150 r / min.

5. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 2, characterized in that: In step S3, after the raw materials are ball-milled, a dispersant and a binder need to be added for ball milling again.

6. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 2, characterized in that: In step S1, the raw material after ball milling is sieved and dried before being processed into mud.

7. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 6, characterized in that: The drying process involves drying the slurry to a moisture content of 19%-23% and refining the mud for 8-24 hours.

8. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 2, characterized in that: The sintering temperature of the raw material after pressing and molding is 1280℃-1320℃, and the holding temperature is 1h. And / or the sintering temperature of the glazed ceramic pot is 1100℃-1200℃, and the temperature is held for 4 hours; And / or the drying process is carried out under a nitrogen atmosphere at a temperature of 1000℃-1100℃ for 1 hour.

9. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 8, characterized in that: The sintering regime for the raw material after pressing and molding is as follows: heating at 2℃ / min to 200℃ and holding for 1 hour, heating at 3℃ / min to 500℃ and holding for 2 hours; heating at 2℃ / min to 1320℃ and holding for 1 hour. The sintering regime for the glazed ceramic pot is as follows: heating at 2℃ / min to 200℃ and holding for 1 hour, heating at 2℃ / min to 500℃ and holding for 1 hour, and heating at 5℃ / min to 1200℃ and holding for 4 hours. And / or the sintering regime for drying and sintering under a nitrogen atmosphere is to heat to 200°C at a rate of 2°C / min and hold for 1 hour, and then heat to the target temperature at a rate of 5°C / min and hold for 1 hour.

10. The method for preparing a lithium-based low-expansion ceramic cooker suitable for induction cookers according to claim 2, characterized in that: In step S3, the concentration of the glaze is controlled at 45%-50%; And / or the coating thickness of the magnetic film in step S6 is controlled to be 2-5 mm.

Images