Preparation method of high-strength daily fossil porcelain

Abstract

The invention belongs to the technical field of ceramic preparation, and particularly relates to a preparation method of high-strength daily fossil porcelain. The preparation method comprises the following steps: S1, treating fossil powder with a hydrochloric acid solution, washing the treated fossil powder with water until the fossil powder is neutral, performing surface modification with a coupling agent, and drying the modified fossil powder to obtain activated fossil powder; s2, respectively preparing a bottom layer material, a middle layer material and a surface layer material containing different proportions of activated fossil powder; s3, sequentially paving the bottom layer material, the middle layer material and the surface layer material, and performing graded compression molding to obtain a layered green body; s4, carrying out segmented sintering on the layered green body; and S5, glazing and firing to obtain the high-strength daily fossil porcelain. The fossil powder is composite powder of silicified wood powder, fossil shell powder and fossil coral powder; kH-550 and TMC-311 are adopted as the coupling agents. Through fossil powder modification, layered structure design and accurate process control, efficient utilization of fossil resources and improvement of daily porcelain performance are realized.

Description

Technical Field

[0001] 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. Background Art

[0002] In modern life, daily-use porcelain is widely used as tableware, decorations, etc. However, the performance of traditional daily-use porcelain has some deficiencies. For example, its flexural strength is relatively low, and it is easy to break when subjected to external force collision; its thermal shock stability is poor, and it is easy to crack when the temperature changes suddenly; the surface hardness is insufficient, and it is easy to have scratches, affecting the appearance and service life. In addition, the water absorption rate of traditional daily-use porcelain is relatively high, which may lead to bacterial growth and stain residue.

[0003] The preparation of traditional daily-use porcelain usually uses ordinary minerals such as kaolin, quartz, and feldspar as raw materials, and adopts conventional forming and sintering processes. Although these raw materials and processes can produce daily-use porcelain products that meet the basic use requirements, they face bottlenecks in improving product performance. The existing processes are difficult to make full use of the high-strength, wear-resistant and other characteristics of special materials, and the defects (such as pores, cracks, etc.) that may occur during the sintering process also affect the quality of the final product.

[0004] With the continuous improvement of people's pursuit of quality of life, the performance requirements for daily-use porcelain are also getting higher and higher. Consumers need more durable, more beautiful and safer products, which prompts the ceramic industry to innovate the preparation method of traditional daily-use porcelain. Research and development of high-strength fossil daily-use porcelain using new raw materials and advanced processes to meet the market demand for high-performance daily-use porcelain has become an important development direction in the current ceramic technology field. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing high-strength fossil daily-use porcelain. This method can make full use of fossil resources, and through hierarchical structure design and precise process control, prepare daily-use porcelain products with high strength, high thermal shock stability and low water absorption rate, while realizing the effective utilization of resources and environmental protection production; the present invention also provides high-strength fossil daily-use porcelain products prepared by this method.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: The method for preparing high-strength fossil daily-use porcelain according to the present invention includes the following steps: S1. Treat the fossil powder with hydrochloric acid solution, wash it with water until neutral, then perform surface modification with a coupling agent and dry it to obtain activated fossil powder; S2. Prepare bottom layer material, middle layer material and surface layer material containing different proportions of activated fossil powder respectively; S3. Lay the bottom layer material, middle layer material and surface layer material in sequence and press them into shape by grading to obtain a layered green body; S4. Sinter the layered green body in segments; S5. Apply glaze and fire to obtain high-strength fossil daily-use porcelain.

[0007] Wherein: The fossil powder is a composite powder of petrified wood powder, fossil shell powder, and fossil coral powder, and the mass ratio of the three is petrified wood powder: fossil shell powder: fossil coral powder = (6 - 10): (1 - 3): (0.5 - 2), and the average particle size is 10 - 50 μm. The petrified wood powder has an excellent silicon skeleton structure, which can provide a good strength foundation; the fossil shell powder is rich in calcium carbonate and can be used as a flux to reduce the sintering temperature; the fossil coral powder has a unique porous structure, which is beneficial to reducing the thermal expansion coefficient of the product. Through the optimized compounding ratio, the synergistic effect of each component can be realized.

[0008] Specifically, the average particle size of the above composite fossil powder is 10 - 50 μm, which is achieved by a conventional sieving process.

[0009] Specifically, the concentration of the hydrochloric acid solution in S1 is 10 - 25%, and the treatment time is 20 - 60 min. Hydrochloric acid treatment can remove impurities and pollutants on the surface of the fossil powder, expose more active sites, and create good conditions for subsequent coupling agent modification.

[0010] Specifically, the silane coupling agent is used after compounding 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) for compounding, and the total dosage is 0.5 - 4% of the mass of the fossil powder. The modification temperature is 70 - 130 °C, the treatment time is 30 - 60 min, and the drying time is 1 - 5 h. KH-550 is an amino silane coupling agent, which can form a covalent bond with the silanol groups on the surface of the fossil powder, and at the same time, the amino group can form a hydrogen bond with the organic matrix; the TMC-311 titanate coupling agent has excellent heat resistance and interfacial bonding performance. The compound use of the two coupling agents can form a dense modification layer on the surface of the fossil powder, significantly improving the interfacial bonding strength with the ceramic matrix.

[0011] Specifically, in S2, it is formulated by mass parts: the bottom layer material contains 40 - 60 parts of kaolin, 15 - 30 parts of feldspar, 10 - 25 parts of quartz, and 11 - 15 parts of activated fossil powder; the middle layer material contains 45 - 65 parts of kaolin, 20 - 35 parts of feldspar, 15 - 30 parts of quartz, and 4 - 10 parts of activated fossil powder; the surface layer material contains 50 - 70 parts of kaolin, 25 - 40 parts of feldspar, 20 - 35 parts of quartz, and 1 - 5 parts of activated fossil powder. Through the hierarchical design, the bottom layer contains more activated fossil powder to provide strength support, the middle layer plays a transitional role, and the surface layer has a smaller content of fossil powder to ensure the surface quality.

[0012] Specifically, in S3, the bottom pressing pressure is 15 - 25 MPa, the middle pressing pressure is 12 - 20 MPa, and the surface pressing pressure is 10 - 18 MPa. The graded pressing can ensure the density and bonding strength of each layer, and avoid delamination defects caused by improper pressure.

[0013] Specifically, the segmented sintering in S4 includes: the first stage of heating to 550 - 700 °C at a heating rate of 2 - 6 °C / min and holding for 0.5 - 2 h, mainly to remove organic matter and binders; the second stage of heating to 1000 - 1200 °C at a heating rate of 1 - 4 °C / min and holding for 1 - 3 h for pre-sintering; the third stage of heating to 1250 - 1350 °C at a heating rate of 1.0 - 2.5 °C / min and holding for 2 - 5 h to complete densification sintering.

[0014] Specifically, the glaze in S5 contains 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, it is fired at 1180 - 1280 °C for 0.8 - 2.5 h.

[0015] The beneficial effects of the present invention are as follows: 1. The pretreatment and surface modification of fossil powder significantly improve the compatibility and interfacial bonding strength with the ceramic matrix. Hydrochloric acid treatment removes surface impurities and exposes more active sites; coupling agent modification forms an organic-inorganic transition layer on the surface of fossil powder, effectively reducing interfacial stress concentration and improving the overall strength of the product.

[0016] 2. The layered structure design realizes the gradient distribution of properties. The high fossil powder content in the bottom layer provides a strength foundation, the low fossil powder content in the surface layer ensures the surface quality, and the middle layer plays a transitional role. This design avoids the problem of uneven properties that may be brought by a single component.

[0017] 3. The graded pressing forming 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, and the interfacial stress caused by too large density difference can be prevented.

[0018] 4. The segmented sintering process realizes precise temperature control. The first stage removes organic matter at low temperature, the second stage pre-sinters at medium temperature, and the third stage densifies at high temperature. Each stage has its specific physical and chemical processes to ensure the sintering quality.

[0019] 5. The synergistic effect of the composite fossil powder gives full play to the advantages of each component. Silicified wood provides skeletal strength, fossil shells reduce the sintering temperature, and fossil corals improve the thermal shock performance. The synergistic effect of the three significantly improves the comprehensive performance of the product.

[0020] 6. The prepared high-strength fossil household porcelain has excellent comprehensive properties: flexural strength ≥ 80 MPa, far higher than 40 - 60 MPa of ordinary household porcelain; thermal shock stability temperature difference ≥ 150 °C, meeting the use requirements of household porcelain; surface hardness ≥ 6 Mohs hardness, with good wear resistance; water absorption rate ≤ 0.8%, meeting the high-quality porcelain standard. Detailed implementation manners

[0021] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to these embodiments. Those skilled in the art should recognize that the present invention covers all possible alternative solutions, improvement solutions, and equivalent solutions within the scope of the claims.

[0022] Silicified wood: Purchased from Lianyungang Xiukuang Arts & Crafts Co., Ltd.

[0023] The remaining raw materials are conventional products with no special requirements and are all obtained through market purchase.

[0024] The average particle size of the composite fossil powder is 10 - 50 μm, which is achieved through a conventional sieving process.

[0025] Example 1;

[0026] Mix silicified wood powder, fossil shell powder, and fossil coral powder in a mass ratio of 8:2:1, and sieve to obtain a composite fossil powder with an average particle size of 30 μm. Treat the composite fossil powder with 15% hydrochloric acid solution for 40 min, wash with water until neutral, and then filter.

[0027] Compound KH-550 and TMC-311 in a mass ratio of 1:0.8, with a total dosage of 2% of the mass of the fossil powder. Treat at 100 °C for 45 min, and then dry at 120 °C for 3 h to obtain activated fossil powder.

[0028] Prepare the bottom layer material respectively: 50 parts of kaolin, 22 parts of feldspar, 17 parts of quartz, and 13 parts of activated fossil powder; middle layer material: 55 parts of kaolin, 27 parts of feldspar, 22 parts of quartz, and 7 parts of activated fossil powder; surface layer material: 60 parts of kaolin, 32 parts of feldspar, 27 parts of quartz, and 3 parts of activated fossil powder.

[0029] Lay the bottom layer material, middle layer material, and surface layer material in sequence, with a pressing pressure of 20 MPa for the bottom layer, 16 MPa for the middle layer, and 14 MPa for the surface layer to obtain a layered green body.

[0030] Segmented sintering: In the first stage, heat up to 600 °C at a heating rate of 4 °C / min and hold for 1 h; in the second stage, heat up to 1100 °C at a heating rate of 2.5 °C / min and hold for 2 h; in the third stage, heat up to 1300 °C at a heating rate of 1.8 °C / min and hold for 3.5 h.

[0031] Prepare the glaze: 40 parts of feldspar, 22 parts of quartz, 17 parts of calcite, 12 parts of kaolin, 3 parts of zinc oxide. After glazing, fire at 1230 °C for 1.5 h to obtain high-strength fossil daily-use porcelain.

[0032] Example 2;

[0033] Mix siliconized wood powder, fossil shell powder, and fossil coral powder in a mass ratio of 6:1:0.5, and sieve to obtain composite fossil powder with an average particle size of 50 μm. Treat the composite fossil powder with 25% hydrochloric acid solution for 20 min, wash with water until neutral, and then filter.

[0034] Compound KH-550 and TMC-311 in a mass ratio of 0.5:0.3, with a total dosage of 0.5% of the mass of the fossil powder. Treat at 70 °C for 60 min, and then dry at 100 °C for 5 h to obtain activated fossil powder.

[0035] Prepare the bottom layer material respectively: 40 parts of china clay, 30 parts of feldspar, 25 parts of quartz, 15 parts of activated fossil powder; middle layer material: 45 parts of china clay, 35 parts of feldspar, 30 parts of quartz, 10 parts of activated fossil powder; surface layer material: 50 parts of china clay, 40 parts of feldspar, 35 parts of quartz, 5 parts of activated fossil powder.

[0036] Lay the bottom layer material, middle layer material, and surface layer material in sequence. The pressing pressure for the bottom layer is 25 MPa, the pressing pressure for the middle layer is 20 MPa, and the pressing pressure for the surface layer is 18 MPa to obtain a layered green body.

[0037] Segmented sintering: In the first stage, heat up to 700 °C at a heating rate of 2 °C / min and hold for 2 h; in the second stage, heat up to 1200 °C at a heating rate of 1 °C / min and hold for 3 h; in the third stage, heat up to 1350 °C at a heating rate of 1.0 °C / min and hold for 5 h.

[0038] Prepare the glaze: 35 parts of feldspar, 25 parts of quartz, 20 parts of calcite, 15 parts of kaolin, 5 parts of zinc oxide. After glazing, fire at 1180 °C for 2.5 h to obtain high-strength fossil daily-use porcelain.

[0039] Example 3;

[0040] Mix siliconized wood powder, fossil shell powder, and fossil coral powder in a mass ratio of 10:3:2, and sieve to obtain composite fossil powder with an average particle size of 10 μm. Treat the composite fossil powder with 10% hydrochloric acid solution for 60 min, wash with water until neutral, and then filter.

[0041] Compound KH-550 and TMC-311 in a mass ratio of 2:1.5, with a total dosage of 4% of the mass of the fossil powder. Treat at 130 °C for 30 min, and then dry at 150 °C for 1 h to obtain activated fossil powder.

[0042] Prepare the bottom layer material respectively: 60 parts of kaolin, 15 parts of feldspar, 10 parts of quartz, and 11 parts of activated fossil powder; middle layer material: 65 parts of kaolin, 20 parts of feldspar, 15 parts of quartz, and 4 parts of activated fossil powder; surface layer material: 70 parts of kaolin, 25 parts of feldspar, 20 parts of quartz, and 1 part of activated fossil powder.

[0043] Lay the bottom layer material, middle layer material, and surface layer material in sequence. The pressing pressure for the bottom layer is 15 MPa, the pressing pressure for the middle layer is 12 MPa, and the pressing pressure for the surface layer is 10 MPa to obtain a stratified green body.

[0044] Sinter in segments: In the first stage, heat up to 550 °C at a heating rate of 6 °C / min and hold for 0.5 h; in the second stage, heat up to 1000 °C at a heating rate of 4 °C / min and hold for 1 h; in the third stage, heat up to 1250 °C at a heating rate of 2.5 °C / min and hold for 2 h.

[0045] 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 at 1280 °C for 0.8 h to obtain high-strength fossil household porcelain.

[0046] Example 4;

[0047] Mix silicified wood powder, fossil shell powder, and fossil coral powder according to a mass ratio of 7:1.5:1, and sieve to obtain a composite fossil powder with an average particle size of 20 μm. The remaining steps are the same as those in Example 1.

[0048] Comparative Example 1 The fossil powder is not treated with hydrochloric acid and modified with a coupling agent, but is used directly. The remaining steps are the same as those in Example 1.

[0049] Comparative Example 2 Do not adopt a stratified structure. All raw materials are prepared in a single layer according to the ratio of the middle layer material in Example 1. The remaining steps are the same as those in Example 1.

[0050] Comparative Example 3 Do not adopt segmented sintering. Directly heat up to 1300 °C for sintering. The remaining steps are the same as those in Example 1.

[0051] Comparative Example 4 Only use KH-550 as the coupling agent and do not use TMC-311. The remaining steps are the same as those in Example 1.

[0052] Comparative Example 5 Only use silicified wood powder for the fossil powder, and do not add fossil shell powder and fossil coral powder. The remaining steps are the same as those in Example 1.

[0053] Conduct performance tests on the high-strength fossil household porcelain prepared in the examples and comparative examples: (1) Flexural strength test: According to the 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.

[0054] (2) Thermal shock stability test: The specimen was heated in a muffle furnace at a set temperature for 30 min, and then quickly immersed in water at 20 °C to observe whether cracks occurred and measure the maximum temperature difference.

[0055] (3) Surface hardness test: The surface hardness value was measured using a Mohs hardness tester.

[0056] (4) Water absorption test: According to the GB / T 3810.3 standard, the specimen was dried at 110 °C for 24 h and then weighed. Then it was boiled in boiling water for 2 h, cooled and weighed to calculate the water absorption rate.

[0057] The test results are shown in Table 1:

[0058] Table 1 Performance test results According to the data in Table 1, it can be seen that the flexural strength of the high-strength fossil daily-use porcelain prepared in Examples 1-3 is all ≥ 80 MPa, the temperature difference of thermal shock stability is all ≥ 150 °C, the surface hardness is all ≥ 6 Mohs hardness, and the water absorption rate is all ≤ 0.8%. All performance indicators meet the design requirements, indicating that the preparation method of the present invention has remarkable effects.

[0059] In Comparative Example 1, the surface modification treatment of the fossil powder was not carried out, resulting in poor interfacial bonding and obvious decline in various properties; in Comparative Example 2, a single-layer structure was used, and the advantages of the hierarchical design could not be exerted; in Comparative Example 3, segmented sintering was not used, and the sintering quality was poor; in Comparative Examples 4 and 5, the synergistic effects of the composite coupling agent and the composite fossil powder were missing respectively, and the performance decreased but was still better than the first three comparative examples, proving the necessity and synergistic effect of each technical feature of the present invention.

[0060] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered by the protection scope of the present invention.

Claims

1. A preparation method of high-strength fossil daily-use porcelain, characterized in that, The following steps are involved: S1. Treat the fossil powder with a hydrochloric acid solution, wash with water until it is neutral, and then perform surface modification with a coupling agent and dry to obtain activated fossil powder; S2. respectively preparing the bottom layer material, the middle layer material and the 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 blank; S4, sintering the layered green body in sections; S5. Glaze and fire to produce high-strength fossil daily-use porcelain.

2. The method according to claim 1, wherein The fossil powder is a composite powder of silicified wood powder, fossil shell powder and fossil coral powder, the mass ratio of the three is silicified wood powder: fossil shell powder: fossil coral powder (6-10): (1-3): (0.5-2), and the average particle size is 10-50 μm.

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

4. The method according to claim 1, wherein 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 30-60min, and the drying time is 1-5h.

5. The method according to claim 1, characterized in that, The S2 is prepared by weight: 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.

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

7. The method according to claim 1, characterized in that, 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.

8. 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.

9. A high-strength fossil daily-use porcelain prepared by the method according to any one of claims 1-8, characterized in that, Flexural strength ≥80MPa, thermal shock stability temperature difference ≥150℃, surface hardness ≥6 Mohs hardness, water absorption ≤0.8%.

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