A ceramic green body, ceramic body and ceramic article and methods of making the same

Abstract

A kind of ceramic blank, ceramic body and ceramic product and its preparation method, wherein, the ceramic blank includes the following raw materials by mass: 12-16 parts of potassium feldspar, 10-14 parts of diatomite, 18-25 parts of porcelain clay, 25-30 parts of kaolin, 20-25 parts of ball clay, 2-4 parts of dolomite, 0.1-0.2 parts of sodium carbonate, 0.5-1.5 parts of water glass.The porous material diatomite is used to replace quartz in the ceramic blank, to enhance the permeability of the ceramic body, maintain the proportion of plastic clay, improve the forming efficiency of the ceramic body, and the difference between the inner and outer hardness of the wet body is greatly reduced, which can reduce the slow drying time and gradual heating drying time.

Description

Technical Field

[0001] This article relates to the field of ceramic products technology, specifically to a ceramic blank, a ceramic body, and a ceramic product, as well as their preparation methods. Background Technology

[0002] Traditionally, sanitary ceramics were formed using plaster mold slip casting. In recent years, this traditional method has been gradually replaced by high-pressure slip casting with resin molds. High-pressure molding requires the slip to have high permeability to improve efficiency and enhance the uniformity of moisture inside and outside the green body.

[0003] Current high-pressure molding slurries are still made using traditional materials with slightly modified formulations. This primarily involves reducing the amount of clay and increasing the amount of lean materials such as quartz and feldspar to increase the gaps between raw material particles and improve permeability. However, this adjustment method, by reducing plastic clay and increasing lean materials, reduces the plasticity and strength of the green body, significantly weakening its processing and drying properties. This can lead to defects such as cracking, and the reduced strength increases the likelihood of breakage during handling.

[0004] Therefore, there is an urgent need for a ceramic blank, ceramic body, and ceramic product that is suitable for high-pressure molding and has high permeability. Summary of the Invention

[0005] This application provides a ceramic green body, a ceramic product, and a method for preparing the same. In the ceramic green body, diatomaceous earth, a porous material, is used to replace quartz in the green body to enhance the permeability of the ceramic green body, maintain the proportion of plastic clay, improve the forming efficiency of the ceramic green body, and significantly reduce the difference in hardness between the inside and outside of the wet green body, thereby reducing the slow drying time and drying time.

[0006] The first aspect of this application provides a ceramic blank, which, by weight, comprises the following raw materials: 12-16 parts potassium feldspar, 10-14 parts diatomite, 18-25 parts porcelain clay, 25-30 parts kaolin, 20-25 parts ball clay, 2-4 parts dolomite, 0.1-0.2 parts sodium carbonate, and 0.5-1.5 parts water glass.

[0007] In one exemplary embodiment, the ceramic blank, by weight, comprises the following raw materials: 12 parts potassium feldspar, 10 parts diatomaceous earth, 24 parts porcelain clay, 30 parts kaolin, 20 parts ball clay, 4 parts dolomite, 0.1 parts sodium carbonate, and 1.5 parts water glass.

[0008] In one exemplary embodiment, the ceramic blank, by weight, comprises the following raw materials: 15 parts potassium feldspar, 10 parts diatomite, 25 parts porcelain clay, 25 parts kaolin, 23 parts ball clay, 2 parts dolomite, 0.1 parts sodium carbonate, and 1.2 parts water glass.

[0009] In one exemplary embodiment, the ceramic blank, by weight, comprises the following raw materials: 16 parts potassium feldspar, 12 parts diatomite, 20 parts porcelain clay, 27 parts kaolin, 23 parts ball clay, 2 parts dolomite, 0.15 parts sodium carbonate, and 1.2 parts water glass.

[0010] In one exemplary embodiment, the ceramic blank, by weight, comprises the following raw materials: 16 parts potassium feldspar, 14 parts diatomite, 18 parts porcelain clay, 25 parts kaolin, 25 parts ball clay, 2 parts dolomite, 0.2 parts sodium carbonate, and 0.5 parts water glass.

[0011] In one exemplary embodiment, the potassium feldspar is Zhangzhou potassium feldspar, the diatomite is Yunnan diatomite, the porcelain clay is Yongchun porcelain clay, the kaolin is Zhangzhou kaolin, the ball clay is Qingyuan ball clay, and the dolomite is Meizhou dolomite.

[0012] The second aspect of this application provides a method for preparing the above-mentioned ceramic blank, comprising the following steps:

[0013] According to the mass ratio, the raw materials potassium feldspar, diatomaceous earth, porcelain clay, kaolin, ball clay, dolomite, sodium carbonate, and water glass are ball-milled with water to obtain a mixture; after the mixture exits the mill, it is sieved, iron is removed, slurry is prepared, and aged to obtain the slurry of the ceramic body.

[0014] In one exemplary embodiment, the mass ratio of the raw material to water is 100:(38-42); preferably, the mass ratio of the raw material to water is 100:40.

[0015] In one exemplary embodiment, the parameters of the mixture after sieving are: the proportion of particles with a particle size of less than 10 μm is 53%-57%.

[0016] In one exemplary embodiment, the slurry preparation includes: adding water and water glass to the mixture to adjust the slurry properties;

[0017] Optionally, the physical parameters of the mud are: specific gravity 1.77-1.79, initial flow velocity V0: 35-50s, and flow velocity V after 30min. 30 : 68-80s, mud temperature 36-40℃; Here, the specific gravity of the mud is calculated as weight / volume, usually referring to the mass of 100ml of mud; the flow rate of the mud generally refers to the time it takes for 100ml of mud to flow out from a 4mm orifice.

[0018] In one exemplary embodiment, the aging time is 6 days.

[0019] A third aspect of this application provides a ceramic blank prepared from the above-described ceramic blank.

[0020] The fourth aspect of this application provides a method for preparing the above-mentioned ceramic green body, comprising the following steps:

[0021] The ceramic blank slurry is pressed under high pressure to form a wet blank; the wet blank is then dried to obtain the ceramic body.

[0022] In one exemplary embodiment, the pressure of the high-pressure pressing is 0.95-1.05 MPa.

[0023] In one exemplary embodiment, the drying includes slow drying and gradual heating drying; wherein, the slow drying involves covering the wet blank with a plastic film at room temperature to ensure uniform moisture content inside and outside the wet blank.

[0024] In one exemplary embodiment, the parameters for the slow drying are: room temperature and drying time of 14-18 hours; preferably, the drying time is 16 hours.

[0025] In one exemplary embodiment, the parameters for the gradual heating and drying are: gradually heating to a temperature less than or equal to 90°C, and drying time of 30-40 hours; preferably, drying time of 36 hours.

[0026] The fifth aspect of this application provides a ceramic article comprising the ceramic body.

[0027] In one exemplary embodiment, the ceramic article further includes a glaze layer coated on the ceramic body.

[0028] In one exemplary embodiment, the ceramic product may be a kitchen and bathroom product, and optionally, the ceramic product may be a toilet, a washbasin, a urinal, a mop, etc.

[0029] The sixth aspect of this application provides a method for preparing a ceramic article, comprising firing the ceramic article after glazing the ceramic body.

[0030] In one exemplary embodiment, the firing process includes firing in an oxidizing atmosphere using a shuttle kiln or a tunnel kiln.

[0031] Optionally, the firing temperature is 1200-1230℃, and the holding time is 0.5-2 hours.

[0032] This application has the following technical effects:

[0033] In this application, diatomaceous earth, a porous material, is used to replace quartz in the traditional formula for ceramic blanks to enhance the permeability of the ceramic blanks and maintain the proportion of plastic clay. Although the main component of diatomaceous earth is also quartz, the structure of diatomaceous earth itself has a large number of pores. This allows the water in the slurry to drain through not only the gaps between particles, but also the pores of the diatomaceous earth particles themselves, increasing the permeability of the slurry, significantly reducing the high-pressure time, improving the forming efficiency of the ceramic blanks, and at the same time, significantly reducing the hardness difference between the inside and outside of the wet blanks, which can reduce the slow drying time and the overall drying time.

[0034] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application may be realized and obtained by means of the methods described in the description. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to embodiments, but this is not intended to limit the present invention. Any equivalent substitutions made in accordance with the disclosure of the present invention shall fall within the protection scope of the present invention.

[0036] The raw materials used in the embodiments and comparative examples of this application have the chemical compositions shown in Table 1 below.

[0037] Table 1

[0038]

[0039] The present invention will be further described in detail below through specific embodiments.

[0040] In the following specific embodiments, operations without specified conditions are performed under standard conditions or conditions recommended by the manufacturer. Raw materials without specified manufacturers and specifications are all commercially available products.

[0041] Example 1.

[0042] The composition of the ceramic body is shown in Table 2 below;

[0043] Preparation method:

[0044] 1) According to the mass ratio, the raw materials potassium feldspar, diatomite, porcelain clay, kaolin, ball clay, dolomite, sodium carbonate, and water glass are ball-milled with water to obtain a mixture, wherein the mass ratio of the raw materials to water is 100:40, and the proportion of particles with a particle size of less than 10μm is 56.5%.

[0045] 2) After milling, the mixture is sieved, iron is removed, water and water glass are added to adjust the slurry, and it is aged for 6 days to obtain the ceramic blank slurry; wherein, the physical parameters of the mixture are: specific gravity 1.77, 85, initial flow rate V0: 45s, and flow rate V after 30min. 30 72s, pulp temperature 39.5℃;

[0046] 3) The slurry is pressurized to form a wet blank; wherein, the pressure of the high-pressure pressing is 1.01 MPa, the time for high-pressure pressing to reach a blank thickness of 10 mm is 450 seconds, and the hardness difference between the inner and outer sides of the blank is 10.

[0047] 4) The wet blank is slowly dried at room temperature for 16 hours until the wet blank does not crack and the shrinkage rate is small. Then, the temperature is raised to 50°C for 6 hours, then to 65°C for 8 hours, and finally to 88°C for 4 hours. The temperature is kept at 88°C for 18 hours and then dried at 88°C for 36 hours to obtain the ceramic blank.

[0048] 5) After drying, the ceramic body is glazed normally and fired in a tunnel kiln with an oxygen coefficient of 2% for a firing cycle of 19 hours. First, the temperature is raised to 800℃ in 6 hours, then to 1100℃ in 4 hours, and then to the highest firing temperature of 1225℃ in 1 hour. The temperature is held for 1 hour, and then cooled to room temperature in 8 hours.

[0049] Examples 2-4.

[0050] The composition of the billet is shown in Table 2 below; the preparation method is the same as in Example 1.

[0051] Comparative Examples 1-2.

[0052] The composition of the billet is shown in Table 2 below; the preparation method is the same as in Example 1.

[0053] Experimental example.

[0054] The molding performance of Examples 1-3 and Comparative Examples 1-2 of this application was compared, and the results are shown in Table 2 below.

[0055] According to Table 2:

[0056] 1) The time for high pressure molding to reach a wet blank thickness of 10 mm obtained in the embodiments of this application is 420-450 seconds, while the time for high pressure molding to reach a wet blank thickness of 10 mm in the ordinary formula (i.e., Comparative Examples 1-2) is 490-650 seconds.

[0057] 2) The hardness difference between the inner and outer sides of the blank obtained in the embodiments of this application is 8-12, while the hardness difference between the inner and outer sides of the blank obtained in the ordinary formula (i.e., comparative examples 1-2) is 15-20.

[0058] 3) In the embodiments of this application, after the wet blank is slowly dried at room temperature for 16 hours, the resulting blank does not crack and has a small shrinkage rate; while the slow drying time required for the non-diatomaceous earth formulation (i.e., comparative examples 1-2) to achieve the same effect is generally 24 hours.

[0059] 4) Comparative Example 1 is a conventional billet formula. In addition to the long high-pressure pressing time (650s), the wet billet after mold opening is soft and cannot be shaped. It will deform and collapse after being forcibly demolded.

[0060] 5) Although the proportion of quartz in Comparative Example 2 was increased to improve water permeability and the high pressure time was reduced (from 650s to 490s), the drying strength was significantly reduced to 3MPa due to the reduced proportion of plastic material. The dry blank breakage rate increased to 1.3%, the difference between internal and external moisture content was large at 0.86%, and the difference between internal and external mold hardness was 15. A long and slow drying time is required to make the moisture content of the wet blank uniform before drying can be carried out.

[0061] 6) In Example 2 of this application, diatomaceous earth was used to replace the quartz in Comparative Example 1. Without adjusting other ribbed materials, the high-pressure time was significantly reduced. At the same time, compared with Comparative Example 2, the strength was not significantly reduced, the difference between internal and external moisture content was significantly reduced, and the difference between internal and external hardness after mold opening was significantly reduced to 9. Only slow drying for 16 hours was required, and other molding properties were not significantly different. Meanwhile, Examples 1, 3, and 4, like Example 2, all used diatomaceous earth to replace the quartz in Comparative Example 1. The difference is that Examples 1, 3, and 4 adjusted the constituent materials within a certain range, and their molding properties were not significantly different from those of Example 2. They all achieved the results of reducing high-pressure time, reducing slow drying time, and improving production efficiency, and could solve the technical problems of this application.

[0062] Table 2

[0063]

[0064] This application describes several embodiments, but these descriptions are exemplary and not restrictive, and it will be apparent to those skilled in the art that there are many more embodiments and implementations within the scope of the embodiments described herein.

Claims

1. A ceramic green body prepared from a ceramic blank, said ceramic green body comprising, by weight, the following raw materials: Potassium feldspar 12-16 parts, diatomite 10-14 parts, porcelain clay 18-25 parts, kaolin 25-30 parts, ball clay 20-25 parts, dolomite 2-4 parts, sodium carbonate 0.1-0.2 parts, water glass 0.5-1.5 parts.

2. The ceramic green body according to claim 1, wherein, The ceramic blank, by weight, is composed of the following raw materials: 12 parts potassium feldspar, 10 parts diatomaceous earth, 24 parts porcelain clay, 30 parts kaolin, 20 parts spherical clay, 4 parts dolomite, 0.1 parts sodium carbonate, and 1.5 parts water glass; or The ceramic blank, by weight, is composed of the following raw materials: 15 parts potassium feldspar, 10 parts diatomaceous earth, 25 parts porcelain clay, 25 parts kaolin, 23 parts spherical clay, 2 parts dolomite, 0.1 parts sodium carbonate, and 1.2 parts water glass; or The ceramic blank, by weight, is composed of the following raw materials: 16 parts potassium feldspar, 12 parts diatomaceous earth, 20 parts porcelain clay, 27 parts kaolin, 23 parts spherical clay, 2 parts dolomite, 0.15 parts sodium carbonate, and 1.2 parts water glass; or The ceramic blank, by weight, is composed of the following raw materials: 16 parts potassium feldspar, 14 parts diatomite, 18 parts porcelain clay, 25 parts kaolin, 25 parts ball clay, 2 parts dolomite, 0.2 parts sodium carbonate, and 0.5 parts water glass.

3. The ceramic green body according to claim 1 or 2, wherein, The potassium feldspar is Zhangzhou potassium feldspar; and / or The diatomite is Yunnan diatomite; and / or The porcelain clay is Yongchun porcelain clay; and / or The kaolin is Zhangzhou kaolin; and / or The ball soil is Qingyuan ball soil; and / or The dolomite mentioned is Meizhou dolomite.

4. A method for preparing a ceramic green body according to any one of claims 1 to 3, comprising the following steps: According to the mass ratio, the raw materials potassium feldspar, diatomite, porcelain clay, kaolin, ball clay, dolomite, sodium carbonate, and water glass are ball-milled with water to obtain a mixture; after the mixture is discharged from the mill, it is sieved, iron is removed, slurry is prepared, and aged to obtain the slurry of the ceramic body. The ceramic blank slurry is pressurized under high pressure to form a wet blank; The wet blank is dried to obtain the ceramic blank.

5. The method according to claim 4, wherein, The mass ratio of the raw material to water is 100:(38-42); and / or The parameters of the mixture after sieving are as follows: the proportion of particles with a particle size of less than 10μm is 53%-57%; and / or The slurry preparation includes: adding water and water glass to the mixture to adjust the slurry properties; and / or The aging time is 6 days.

6. The method according to claim 5, wherein, The mass ratio of the raw material to water is 100:40; The physical parameters of the mud are: specific gravity 1.77-1.79, initial flow velocity V0: 35-50s, and flow velocity V after 30min. 30 : 68-80s, pulp temperature 36-40℃.

7. The method according to any one of claims 4 to 6, wherein, The pressure for high-pressure molding is 0.95-1.05 MPa.

8. The method according to any one of claims 4 to 6, wherein, The drying process includes slow drying and gradual temperature increase drying.

9. The method according to claim 8, wherein, The parameters for the slow drying are: room temperature, drying time 14-18h; The parameters for the gradual heating and drying process are: gradually increasing the temperature to less than or equal to 90°C, and drying time of 30-40 hours.

10. The method according to claim 9, wherein, The slow drying time is 16 hours; The drying time for the gradual temperature increase drying process is 36 hours.

11. A ceramic article, said ceramic article being made from a ceramic body according to any one of claims 1 to 3.

12. The ceramic article according to claim 11, wherein, The ceramic products mentioned are kitchen and bathroom products.

13. The ceramic article according to claim 12, wherein, The ceramic products are: toilets, washbasins, sinks, urinals, or mop basins.

14. A method for preparing a ceramic article according to any one of claims 11 to 13, comprising glazing the ceramic body and then firing it.

15. The method according to claim 14, wherein, The firing process is carried out using a shuttle kiln or tunnel kiln under an oxidizing atmosphere; the firing temperature is 1200-1230℃, and the holding time is 0.5-2h.

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