A method for preparing high-strength fossil daily-use porcelain

Abstract

The present invention belongs to the technical field of ceramic preparation, and specifically relates to a method for preparing high-strength fossil daily-use porcelain. The preparation method of the present invention comprises the following steps: S1, treating fossil powder with hydrochloric acid solution and then washing with water to neutrality, then surface-modifying with a coupling agent and drying to obtain activated fossil powder; S2, respectively preparing a base layer material, a middle layer material and a surface layer material containing different proportions of activated fossil powder; S3, paving the base layer material, the middle layer material and the surface layer material in sequence and performing graded press molding to obtain a layered blank; S4, sintering the layered blank in sections; S5, glazing and firing to obtain high-strength fossil daily-use porcelain. The fossil powder is a composite powder of silicified wood powder, fossil shell powder and fossil coral powder; the coupling agent is KH-550 and TMC-311. The present invention realizes the efficient utilization of fossil resources and the improvement of the performance of daily-use porcelain through fossil powder modification, layered structure design and precise process control.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramic preparation, and in particular relates to a method for preparing high-strength fossil daily-use porcelain. Background Art

[0002] In modern life, household porcelain is widely used as tableware and decorative items. However, traditional household porcelain has some performance shortcomings. For example, its low flexural strength makes it susceptible to breakage from external impact; its poor thermal shock resistance makes it prone to cracking when subjected to sudden temperature changes; and its insufficient surface hardness makes it prone to scratches, affecting its aesthetics and lifespan. Furthermore, traditional household porcelain has a high water absorption rate, which can lead to bacterial growth and residual stains.

[0003] Traditional household porcelain is typically produced using common minerals such as porcelain clay, quartz, and feldspar, using conventional molding and sintering processes. While these raw materials and processes can produce household porcelain products that meet basic usage requirements, they face bottlenecks in improving product performance. Existing processes struggle to fully utilize the high strength and wear resistance of specialized materials, and defects (such as pores and cracks) that may appear during sintering also affect the quality of the final product.

[0004] As people's pursuit of a higher quality of life continues to improve, the performance requirements for household porcelain are also increasing. Consumers demand more durable, more beautiful, and safer products, which forces the ceramic industry to innovate the production methods of traditional household porcelain. Research and development of high-strength fossil-based household porcelain using new raw materials and advanced processes to meet market demand for high-performance household porcelain has become a key development direction in the current ceramic technology field. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing high-strength fossil daily-use porcelain. The method can fully utilize fossil resources and, through layered structure design and precise process control, prepare daily-use porcelain products with high strength, high thermal shock stability, and low water absorption, while achieving effective resource utilization and environmentally friendly production. The present invention also provides high-strength fossil daily-use porcelain products prepared by this method.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] The method for preparing high-strength fossil household porcelain of the present invention comprises the following steps: S1, treating fossil powder with a hydrochloric acid solution, washing with water until neutral, performing surface modification with a coupling agent, and drying to obtain activated fossil powder; S2, respectively preparing a base layer material, a middle layer material, and a surface layer material containing activated fossil powder in different proportions; S3, laying the base layer material, the middle layer material, and the surface layer material in sequence and pressing and forming them in stages to obtain a layered green body; S4, sintering the layered green body in stages; and S5, glazing and firing to obtain the high-strength fossil household porcelain.

[0008] in:

[0009] The fossil powder is a composite of silicified wood powder, fossil shell powder, and fossil coral powder. The mass ratio of silicified wood powder: fossil shell powder: fossil coral powder is (6-10): (1-3): (0.5-2), with an average particle size of 10-50 μm. The silicified wood powder has an excellent siliceous skeleton structure, providing a strong foundation for strength; the fossil shell powder is rich in calcium carbonate, which acts as a flux to lower the sintering temperature; and the fossil coral powder has a unique porous structure, which helps reduce the thermal expansion coefficient of the product. By optimizing the compounding ratio, the components can achieve a synergistic effect.

[0010] Specifically, the average particle size of the composite fossil powder is 10-50 μm, which is achieved through a conventional screening process.

[0011] Specifically, the concentration of the hydrochloric acid solution in S1 is 10-25%, and the treatment time is 20-60 minutes. The hydrochloric acid treatment can remove impurities and contaminants on the surface of the fossil powder, exposing more active sites and creating good conditions for subsequent coupling agent modification.

[0012] Specifically, the silane coupling agent is a compound of KH-550 and a titanate coupling agent, TMC-311. The mass ratio of KH-550 to TMC-311 is (0.5-2):(0.3-1.5), and the total dosage is 0.5-4% of the fossil powder mass. The modification temperature is 70-130°C, the treatment time is 30-60 minutes, and the drying time is 1-5 hours. KH-550 is an aminosilane coupling agent that forms covalent bonds with the silanol groups on the fossil powder surface, while the amino groups can form hydrogen bonds with the organic matrix. TMC-311, a titanate coupling agent, has excellent heat resistance and interfacial bonding properties. The combination of the two coupling agents forms a dense modified layer on the fossil powder surface, significantly improving the interfacial bonding strength with the ceramic substrate.

[0013] Specifically, the S2 layer is formulated in parts by weight: the bottom layer comprises 40-60 parts china clay, 15-30 parts feldspar, 10-25 parts quartz, and 11-15 parts activated fossil powder; the middle layer comprises 45-65 parts china clay, 20-35 parts feldspar, 15-30 parts quartz, and 4-10 parts activated fossil powder; and the top layer comprises 50-70 parts china clay, 25-40 parts feldspar, 20-35 parts quartz, and 1-5 parts activated fossil powder. Through a layered design, the bottom layer contains more activated fossil powder to provide strength support, the middle layer serves as a transition, and the top layer contains less fossil powder to ensure surface quality.

[0014] Specifically, the pressing pressure of the bottom layer in S3 is 15-25 MPa, the pressing pressure of the middle layer is 12-20 MPa, and the pressing pressure of the surface layer is 10-18 MPa. Gradual pressing can ensure the density and bonding strength of each layer and avoid delamination defects caused by improper pressure.

[0015] Specifically, the staged sintering in S4 includes: the first stage is heating to 550-700°C, heating rate 2-6°C / min, and keeping warm for 0.5-2h, mainly to remove organic matter and binder; the second stage is heating to 1000-1200°C, heating rate 1-4°C / min, and keeping warm for 1-3h for pre-sintering; the third stage is heating to 1250-1350°C, heating rate 1.0-2.5°C / min, and keeping warm for 2-5h to complete densification sintering.

[0016] Specifically, the glaze in S5 comprises, by mass, 35-45 parts of feldspar, 20-25 parts of quartz, 15-20 parts of calcite, 10-15 parts of kaolin, and 2-5 parts of zinc oxide. After glazing, the glaze is fired at 1180-1280° C. for 0.8-2.5 hours.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. Pretreatment and surface modification of fossil powder significantly improves compatibility and interfacial bonding strength with the ceramic matrix. Hydrochloric acid treatment removes surface impurities, exposing more active sites; coupling agent modification forms an organic-inorganic transition layer on the fossil powder surface, effectively reducing interfacial stress concentration and improving the overall strength of the product.

[0019] 2. The layered structure design achieves a gradient distribution of performance. The bottom layer with high fossil powder content provides the strength foundation, the surface layer with low fossil powder content ensures surface quality, and the middle layer acts as a transition. This design avoids the uneven performance problem that may be caused by a single component.

[0020] 3. The graded pressing process ensures the density of each layer and the bonding between layers. By adjusting the pressing pressure of different layers, the density of each layer can be controlled to prevent the interface stress caused by excessive density difference.

[0021] 4. The staged sintering process achieves precise temperature control. The first stage is low-temperature removal of organic matter, the second stage is medium-temperature pre-sintering, and the third stage is high-temperature densification. Each stage has its own specific physical and chemical processes to ensure sintering quality.

[0022] 5. The synergistic effect of composite fossil powder fully utilizes the advantages of each component. Petrified wood provides skeleton strength, fossil shells reduce sintering temperature, and fossil coral improves thermal shock resistance. The synergistic effect of the three significantly enhances the overall performance of the product.

[0023] 6. The prepared high-strength fossil daily-use porcelain has excellent comprehensive properties: flexural strength ≥80MPa, much higher than the 40-60MPa of ordinary daily-use porcelain; thermal shock stability temperature difference ≥150℃, meeting the use requirements of daily-use porcelain; surface hardness ≥6 Mohs hardness, with good wear resistance; water absorption rate ≤0.8%, meeting the standards of high-quality porcelain. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to these embodiments. Those skilled in the art should appreciate that the present invention encompasses all possible alternatives, improvements, and equivalents within the scope of the claims.

[0025] Petrified wood: purchased from Lianyungang Xiukuang Arts & Crafts Co., Ltd.

[0026] The remaining raw materials are conventional products with no special requirements and are all obtained through commercial channels.

[0027] The average particle size of the composite fossil powder is 10-50 μm, which is achieved through conventional screening process.

[0028] Example 1;

[0029] Silicified wood powder, fossil shell powder, and fossil coral powder were mixed in a mass ratio of 8:2:1 and sieved to obtain composite fossil powder with an average particle size of 30 μm. The composite fossil powder was treated with a 15% hydrochloric acid solution for 40 minutes, washed with water until neutral, and then filtered.

[0030] KH-550 and TMC-311 were compounded in a mass ratio of 1:0.8, with a total amount of 2% of the mass of the fossil powder. The mixture was treated at 100°C for 45 minutes and then dried at 120°C for 3 hours to obtain activated fossil powder.

[0031] Prepare the bottom layer materials respectively: 50 parts of porcelain clay, 22 parts of feldspar, 17 parts of quartz, and 13 parts of activated fossil powder; the middle layer materials: 55 parts of porcelain clay, 27 parts of feldspar, 22 parts of quartz, and 7 parts of activated fossil powder; the surface layer materials: 60 parts of porcelain clay, 32 parts of feldspar, 27 parts of quartz, and 3 parts of activated fossil powder.

[0032] The bottom layer material, middle layer material and surface layer material are laid in sequence, with the bottom layer pressing at a pressure of 20 MPa, the middle layer pressing at a pressure of 16 MPa and the surface layer pressing at a pressure of 14 MPa to obtain a layered green body.

[0033] Staged sintering: in the first stage, the temperature is raised to 600°C at a heating rate of 4°C / min and kept warm for 1 hour; in the second stage, the temperature is raised to 1100°C at a heating rate of 2.5°C / min and kept warm for 2 hours; in the third stage, the temperature is raised to 1300°C at a heating rate of 1.8°C / min and kept warm for 3.5 hours.

[0034] Prepare the glaze: 40 parts of feldspar, 22 parts of quartz, 17 parts of calcite, 12 parts of kaolin, and 3 parts of zinc oxide. After glazing, fire it at 1230℃ for 1.5 hours to produce high-strength fossil daily-use porcelain.

[0035] Example 2;

[0036] Silicified wood powder, fossil shell powder, and fossil coral powder were mixed in a mass ratio of 6:1:0.5 and sieved to obtain a composite fossil powder with an average particle size of 50 μm. The composite fossil powder was treated with a 25% hydrochloric acid solution for 20 minutes, washed with water until neutral, and then filtered.

[0037] KH-550 and TMC-311 were compounded in a mass ratio of 0.5:0.3, with a total amount of 0.5% of the mass of the fossil powder. The mixture was treated at 70°C for 60 minutes and then dried at 100°C for 5 hours to obtain activated fossil powder.

[0038] Prepare the bottom layer materials separately: 40 parts of porcelain clay, 30 parts of feldspar, 25 parts of quartz, and 15 parts of activated fossil powder; the middle layer materials: 45 parts of porcelain clay, 35 parts of feldspar, 30 parts of quartz, and 10 parts of activated fossil powder; the surface layer materials: 50 parts of porcelain clay, 40 parts of feldspar, 35 parts of quartz, and 5 parts of activated fossil powder.

[0039] The bottom layer material, middle layer material and surface layer material are laid in sequence, with the bottom layer pressing at a pressure of 25 MPa, the middle layer pressing at a pressure of 20 MPa and the surface layer pressing at a pressure of 18 MPa to obtain a layered green body.

[0040] Staged sintering: in the first stage, the temperature is raised to 700°C at a heating rate of 2°C / min and kept warm for 2 hours; in the second stage, the temperature is raised to 1200°C at a heating rate of 1°C / min and kept warm for 3 hours; in the third stage, the temperature is raised to 1350°C at a heating rate of 1.0°C / min and kept warm for 5 hours.

[0041] Prepare the glaze: 35 parts of feldspar, 25 parts of quartz, 20 parts of calcite, 15 parts of kaolin, and 5 parts of zinc oxide. After glazing, fire it at 1180℃ for 2.5 hours to produce high-strength fossil daily porcelain.

[0042] Example 3;

[0043] Silicified wood powder, fossil shell powder, and fossil coral powder were mixed in a mass ratio of 10:3:2 and sieved to obtain a composite fossil powder with an average particle size of 10 μm. The composite fossil powder was treated with a 10% hydrochloric acid solution for 60 minutes, washed with water until neutral, and then filtered.

[0044] KH-550 and TMC-311 were compounded in a mass ratio of 2:1.5, with a total amount of 4% of the mass of the fossil powder. The mixture was treated at 130°C for 30 minutes and then dried at 150°C for 1 hour to obtain activated fossil powder.

[0045] Prepare the bottom layer materials separately: 60 parts of porcelain clay, 15 parts of feldspar, 10 parts of quartz, and 11 parts of activated fossil powder; the middle layer materials: 65 parts of porcelain clay, 20 parts of feldspar, 15 parts of quartz, and 4 parts of activated fossil powder; the surface layer materials: 70 parts of porcelain clay, 25 parts of feldspar, 20 parts of quartz, and 1 part of activated fossil powder.

[0046] The bottom layer material, middle layer material and surface layer material are laid in sequence, with the bottom layer pressing at a pressure of 15 MPa, the middle layer pressing at a pressure of 12 MPa and the surface layer pressing at a pressure of 10 MPa to obtain a layered green body.

[0047] Staged sintering: in the first stage, the temperature is raised to 550°C at a heating rate of 6°C / min and kept warm for 0.5h; in the second stage, the temperature is raised to 1000°C at a heating rate of 4°C / min and kept warm for 1h; in the third stage, the temperature is raised to 1250°C at a heating rate of 2.5°C / min and kept warm for 2h.

[0048] Prepare the glaze: 45 parts of feldspar, 20 parts of quartz, 15 parts of calcite, 10 parts of kaolin, and 2 parts of zinc oxide. After glazing, fire it at 1280℃ for 0.8h to produce high-strength fossil daily-use porcelain.

[0049] Example 4;

[0050] Silicified wood powder, fossil shell powder, and fossil coral powder were mixed in a mass ratio of 7:1.5:1 and sieved to obtain composite fossil powder with an average particle size of 20 μm. The remaining steps were the same as in Example 1.

[0051] Comparative Example 1

[0052] The fossil powder was used directly without being treated with hydrochloric acid or modified with a coupling agent. The remaining steps were the same as those in Example 1.

[0053] Comparative Example 2

[0054] No layered structure is used, and all raw materials are prepared in a single layer according to the proportions of the middle layer materials in Example 1. The remaining steps are the same as in Example 1.

[0055] Comparative Example 3

[0056] The temperature was directly raised to 1300° C. for sintering without adopting segmented sintering. The remaining steps were the same as those in Example 1.

[0057] Comparative Example 4

[0058] Only KH-550 was used as the coupling agent, and TMC-311 was not used. The remaining steps were the same as those in Example 1.

[0059] Comparative Example 5

[0060] The fossil powder only uses silicified wood powder, without adding fossil shell powder and fossil coral powder, and the remaining steps are the same as those in Example 1.

[0061] The performance tests were conducted on the high-strength fossil-based daily-use porcelain prepared in the examples and comparative examples:

[0062] (1) Bending strength test: According to GB / T 3810.4 standard, the three-point bending method was used for testing. The specimen size was 100 mm × 25 mm × 6 mm and the loading speed was 1 mm / min.

[0063] (2) Thermal shock stability test: Heat the sample in a muffle furnace at a set temperature for 30 min, then quickly put it into 20°C water to observe whether cracks appear and measure the maximum temperature difference.

[0064] (3) Surface hardness test: Use Mohs hardness tester to measure the surface hardness value.

[0065] (4) Water absorption test: According to GB / T 3810.3, the sample was dried at 110℃ for 24 hours and then weighed. Then it was boiled in boiling water for 2 hours and weighed after cooling to calculate the water absorption.

[0066] The test results are shown in Table 1:

[0067] Table 1 Performance test results

[0068] According to the data in Table 1, the high-strength fossil daily-use porcelain prepared in Examples 1-3 has a flexural strength of ≥80 MPa, a thermal shock stability temperature difference of ≥150°C, a surface hardness of ≥6 Mohs hardness, and a water absorption rate of ≤0.8%. All performance indicators meet the design requirements, indicating that the preparation method of the present invention is significantly effective.

[0069] Comparative Example 1 did not undergo surface modification treatment of the fossil powder, resulting in poor interface bonding and a significant decrease in various performances; Comparative Example 2 adopted a single-layer structure and was unable to take advantage of the layered design; Comparative Example 3 did not adopt segmented sintering, and the sintering quality was poor; Comparative Examples 4 and 5 lacked the synergistic effects of the composite coupling agent and the composite fossil powder, respectively, and their performance declined but was still better than the first three comparative examples, demonstrating the necessity and synergistic effect of the various technical features of the present invention.

[0070] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing high-strength fossil daily-use porcelain, characterized in that: The following steps are involved: S1. Treating fossil powder with a hydrochloric acid solution and then washing with water until neutral, then surface-modifying the powder with a coupling agent and drying the powder to obtain activated fossil powder; the fossil powder is a composite powder of silicified wood powder, fossil shell powder, and fossil coral powder, with a mass ratio of silicified wood powder: fossil shell powder: fossil coral powder of (6-10): (1-3): (0.5-2), and an average particle size of 10-50 μm; S2. respectively preparing the bottom layer material, middle layer material and surface layer material containing different proportions of activated fossil powder; S3, laying the bottom layer material, the middle layer material, and the surface layer material in sequence and pressing them in stages to obtain a layered green body; S4, sintering the layered green body in sections; S5, glazing and firing to produce high-strength fossil daily-use porcelain; The S2 is prepared in parts by mass as follows: bottom layer material: 40-60 parts of china clay, 15-30 parts of feldspar, 10-25 parts of quartz, and 11-15 parts of activated fossil powder; middle layer material: 45-65 parts of china clay, 20-35 parts of feldspar, 15-30 parts of quartz, and 4-10 parts of activated fossil powder; surface layer material: 50-70 parts of china clay, 25-40 parts of feldspar, 20-35 parts of quartz, and 1-5 parts of activated fossil powder.

2. The method according to claim 1, characterized in that The concentration of the hydrochloric acid solution in S1 is 10-25%, and the treatment time is 20-60 minutes.

3. The method according to claim 1, characterized in that The coupling agent in S1 is a compound of silane coupling agent KH-550 and titanate coupling agent TMC-311. The mass ratio of KH-550 to TMC-311 is (0.5-2): (0.3-1.5). The total amount is 0.5-4% of the mass of the fossil powder. The modification temperature is 70-130°C, the processing time is 30-60 minutes, and the drying time is 1-5 hours.

4. The method according to claim 1, wherein The pressing pressure of the bottom layer of S3 is 15-25 MPa, the pressing pressure of the middle layer is 12-20 MPa, and the pressing pressure of the surface layer is 10-18 MPa.

5. The method according to claim 1, wherein The staged sintering in S4 includes: the first stage: heating to 550-700°C, heating rate 2-6°C / min, and keeping warm for 0.5-2h; the second stage: heating to 1000-1200°C, heating rate 1-4°C / min, and keeping warm for 1-3h; the third stage: heating to 1250-1350°C, heating rate 1.0-2.5°C / min, and keeping warm for 2-5h.

6. The method according to claim 1, wherein The glaze in S5 comprises, by mass, 35-45 parts of feldspar, 20-25 parts of quartz, 15-20 parts of calcite, 10-15 parts of kaolin, and 2-5 parts of zinc oxide. After glazing, the glaze is fired at 1180-1280° C. for 0.8-2.5 hours.

7. A high-strength fossil daily-use porcelain prepared by the method according to any one of claims 1 to 6, characterized in that: Bending strength ≥80MPa, thermal shock stability temperature difference ≥150℃, surface hardness ≥6 Mohs hardness, water absorption ≤0.8%.

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