Strong-alkali-resistant lead-free glaze for white porcelain and preparation method thereof

Abstract

The invention relates to the technical field of glaze for porcelain, and particularly discloses strong-alkali-resistant lead-free glaze for white porcelain and a preparation method of the strong-alkali-resistant lead-free glaze. The strong-alkali-resistant lead-free glaze comprises feldspar powder, alumina powder, calcium carbonate powder, dolomite powder, barium carbonate powder, strontium carbonate powder, lithium carbonate powder, boric acid powder, zinc oxide powder, silicon oxide powder, borax powder and kaolin powder. The preparation method comprises the steps of mixing, melting and water quenching. The strong-alkali-resistant lead-free glaze for the white porcelain can be used for glazing porcelain such as bone china, magnesia porcelain and reinforced porcelain, and has the advantages that the alkali resistance of the lead-free glaze is improved, and the adverse effect on the applicability of the prepared porcelain is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of glazes for porcelain, and more specifically, it relates to a strong-alkali-resistant lead-free glaze for white porcelain and a preparation method thereof. Background Art

[0002] Porcelain generally refers to clay or porcelain stone products that are fired at high temperatures, with a relatively dense sintered body and excellent glaze quality. During preparation, fritted glaze is prepared into glaze slurry and then applied to the blank body, and the glazed blank body is baked twice to obtain porcelain.

[0003] Traditional fritted glazes often use limestone and feldspar as the main raw materials, and the lead content is usually higher than 1%. However, when the lead in the glaze fails to form a stable vitreous body during the baking process, it is likely to cause lead dissolution in the obtained porcelain, which is not conducive to people's physical health and is harmful to the environment. Therefore, the development of lead-free glazes has become the development direction of the ceramic industry.

[0004] The firing range of common lead-free glazes is usually below 900°C, and they have poor alkali resistance. Therefore, it is difficult to adapt to a strongly alkaline practical environment, which has an adverse impact on the applicability of the obtained porcelain. Summary of the Invention

[0005] In order to improve the alkali resistance of lead-free glazes and reduce the adverse impact on the applicability of the obtained porcelain, the present application provides a strong-alkali-resistant lead-free glaze for white porcelain and a preparation method thereof.

[0006] In the first aspect, the present application provides a strong-alkali-resistant lead-free glaze for white porcelain, adopting the following technical solution: A strong-alkali-resistant lead-free glaze for white porcelain, comprising the following raw materials in parts by weight: 37 - 41 parts of feldspar powder, 0.5 - 1 part of alumina powder, 1 - 3 parts of calcium carbonate powder, 3 - 7 parts of dolomite powder, 4 - 8 parts of barium carbonate powder, 0.5 - 1 part of strontium carbonate powder, 0.5 - 1.5 parts of lithium carbonate powder, 3 - 4 parts of boric acid powder, 10 - 13 parts of zinc oxide powder, 15 - 20 parts of silicon oxide powder, 3 - 6 parts of borax powder, 3 - 6 parts of kaolin powder.

[0007] By adopting the above technical solution, silicon dioxide, as the main component in the lead-free glaze, plays a role in increasing the melting point, increasing the viscosity, reducing the expansion coefficient, and improving the mechanical strength and hardness in the glaze. Silicon dioxide can form complex silicate compounds with the alkaline oxides in the glaze, and these compounds can resist the erosion of various gases, water, acids, and alkalis; alumina plays a role in increasing the melting point, increasing the viscosity, improving the chemical stability, and reducing the tendency of cracking in the glaze, and can promote the fluidity of the glaze and inhibit the crystallization effect; The feldspar powder provides sodium oxide and potassium oxide in the raw materials, thus serving as a strong flux. Sodium oxide reduces the viscosity of the glaze and increases the thermal expansion coefficient, while potassium oxide increases the brightness of the glaze; Zinc oxide plays a role in fluxing and adjusting the glaze color in lead-free glazes, reducing the melting temperature of the glaze, increasing the fluidity of the glaze, and being able to form stable compounds with other components in the glaze, thereby improving the physical and chemical properties of the glaze; Calcium carbonate and dolomite provide calcium oxide, thus increasing the hardness, wear resistance and chemical stability of the glaze, reducing the expansion coefficient, increasing the mechanical strength, and dolomite also provides magnesium oxide, which can increase the melting temperature range of the glaze at high temperatures, increase the whiteness of the glaze and play a role in preventing glaze surface cracking; Kaolin is used to increase the viscosity of the glaze, enhance the hardness and toughness of the glaze, improve the adhesion and coverage of the glaze, prevent the glaze from melting at high temperatures, and reduce glaze surface cracking and crazing; Borax and boric acid provide boron element to replace lead element, reducing the harm to the environment and human body. And boric acid and borax act as fluxes in lead-free glazes, which can reduce the melting point of the glaze, make the glaze easier to melt, help improve the quality of the glaze surface and the ability to resist climate change, reduce the viscosity and surface tension of the glaze, increase the refractive index of the glaze, thereby increasing the gloss of the glaze surface, and can also increase the mechanical strength and wear resistance of the glaze, promote the rapid ripening and coloring of the glaze, so that the glaze layer reaches the ideal hardness and gloss in a short time; Zinc oxide acts together with other oxides to increase the hardness and transparency of the glaze. Zinc oxide has strong reducibility and oxidizability. During the firing process of the glaze, zinc oxide can reduce other oxides or be oxidized by other oxides at high temperatures, thus releasing a large amount of heat energy to promote the melting of the glaze, and can also reduce the loss of the glaze during firing, making the fired ceramics harder; Zinc oxide has antibacterial and anti-inflammatory effects, which can inhibit the growth of microorganisms in the glaze, prevent the glaze surface from being contaminated and bred by bacteria and molds, increase the gloss and whiteness of the glaze, increase the strength of the glaze, make the ceramics more impact-resistant, increase the hardness of the ceramics, increase the brightness of the ceramics, improve the crack resistance performance, make the glaze surface flexible, reduce the expansion coefficient of the glaze, and improve the thermal stability of the glaze; Barium carbonate can increase the gloss of the glaze surface, make the glaze surface smoother and more delicate, improve the adhesion and hardness of the glaze surface, enhance the durability and wear resistance of ceramic products, and also has a certain impact on the color of the glaze surface, being able to adjust the lightness and hue of the glaze surface; Strontium carbonate can increase the transparency and brightness of ceramic products, make the glaze surface more crystal clear, and can also improve the seismic resistance of the glaze surface, playing a certain role in reducing the cracking rate of ceramic products; Lithium carbonate can increase the melting point of the glaze, enhance the fluidity of the glaze surface, and promote the melting of the glaze surface. This melting and flowing process can make the product surface smooth and delicate, improve the overall quality and aesthetics of the product, change the crystal structure in the glaze surface, thereby making the glaze surface more transparent and shiny. It can also reduce the clouding phenomenon of the glaze surface, improve the transparency and brightness of the glaze surface, increase the surface hardness and anti-pollution property of the product, reduce the corrosion and erosion of the glaze by chemical substances. Lithium carbonate can significantly reduce the melting temperature of the glaze and glass-ceramics. When lithium oxide is used together with sodium oxide and potassium oxide, they will form the lowest eutectic point, further reducing the melting temperature. Lithium carbonate can greatly reduce the viscosity of the glaze and glass-ceramics, which helps to improve the fluidity and uniformity of the glaze.

[0008] Preferably, the raw materials further include 2-4 parts of magnesium silicate powder.

[0009] By adopting the above technical solution, adding magnesium silicate powder to the raw materials, due to the lubricity of magnesium silicate powder itself, adding magnesium silicate powder to the raw materials facilitates the mixing of the components in the raw materials, and then facilitates the uniform dispersion of each component in the raw materials. At the same time, it plays a role in promoting melting. When the mixed raw materials are melted, magnesium silicate is decomposed by heat and forms magnesium oxide and silicon dioxide, reducing the possibility of introducing new impurities into the prepared lead-free glaze.

[0010] Preferably, the magnesium silicate powder is modified magnesium silicate, and the modified magnesium silicate powder is prepared by mixing magnesium silicate powder, a coupling agent and titanium dioxide powder in a weight ratio of (1-3):2:(1-3). The modified magnesium silicate powder is prepared by the following steps: After mixing the coupling agent and titanium dioxide powder in proportion, add magnesium silicate powder in proportion and mix well to obtain the modified magnesium silicate powder.

[0011] By adopting the above technical solution, within the above range, the magnesium silicate powder and titanium dioxide powder are connected by a coupling agent, thereby modifying the magnesium silicate powder, attaching the magnesium silicate powder to the outside of the titanium dioxide powder, facilitating the introduction of titanium dioxide powder into the raw materials, reducing the possibility of agglomeration of titanium dioxide powder in the powder system of the raw materials, improving the dispersibility of titanium dioxide powder, so that the prepared lead-free glaze has self-cleaning and wear resistance during application, reducing the possibility of wear during the cleaning process of the prepared lead-free glaze, and reducing the adverse impact on the applicability of the prepared porcelain.

[0012] Preferably, the coupling agent is coconut oil.

[0013] By adopting the above technical solution, coconut oil is attached to the surface of titanium dioxide, and the titanium dioxide particles with coconut oil wrapped on the surface are mixed with magnesium silicate powder. The lipophilicity of magnesium silicate powder facilitates the attachment of magnesium silicate to the surface of titanium dioxide, improving the binding force between magnesium silicate and titanium dioxide, thereby enhancing the stability and dispersibility of titanium dioxide powder, improving the self-cleaning property and wear resistance of the prepared lead-free glaze, and reducing the adverse impact on the applicability of the prepared porcelain.

[0014] Preferably, the titanium dioxide powder is modified titanium dioxide powder, and the modified titanium dioxide powder is prepared from tetrabutyl titanate and silver nitrate in a weight ratio of 2:(1 - 3).

[0015] Preferably, the modified titanium dioxide powder is prepared by the following steps: Mix tetrabutyl titanate and absolute ethanol in a weight ratio of 1:(6 ± 1), then add glacial acetic acid and mix well. The weight ratio of tetrabutyl titanate to glacial acetic acid is 1:(1 ± 0.5) to obtain a mixed solution A; Mix deionized water and absolute ethanol in a weight ratio of 3:(3 ± 1), and add silver nitrate and mix well to obtain a mixed solution B; Drop the mixed solution B into the mixed solution A drop by drop and stir until a light yellow transparent sol is formed; Dry the obtained sol at 80 ± 5 °C for 24 ± 2 h to obtain a gel; Calcine the obtained gel at 650 ± 50 °C for 2 ± 1 h, cool and crush to obtain the modified titanium dioxide powder.

[0016] By adopting the above technical solution, the modified titanium dioxide powder is prepared from tetrabutyl titanate and silver nitrate by the sol-gel method, so that silver is wrapped on the surface of titanium dioxide, forming a "core-shell" structure when the modified titanium dioxide is mixed with magnesium silicate powder, further improving the dispersibility and stability of titanium dioxide powder, endowing the prepared lead-free glaze with antibacterial properties, inhibiting the growth and spread of bacteria, thereby enhancing the corrosion resistance of the prepared lead-free glaze, and reducing the adverse impact on the applicability of the prepared porcelain.

[0017] In the second aspect, the present application provides a preparation method of a strong alkali-resistant lead-free glaze for white porcelain, adopting the following technical solution: A preparation method of a strong alkali-resistant lead-free glaze for white porcelain, comprising the following steps: Mix feldspar powder, alumina powder, calcium carbonate powder, dolomite powder, barium carbonate powder, strontium carbonate powder, lithium carbonate powder, boric acid powder, zinc oxide powder, silicon oxide powder, borax powder, kaolin powder according to a weight ratio to obtain a mixed powder; Melt the obtained mixed powder at 1500 - 1600 °C, and then perform water quenching to obtain the strong alkali-resistant lead-free glaze for white porcelain.

[0018] By adopting the above technical solution, after mixing the powders in the raw materials and then performing melting and water quenching, a lead-free glaze is obtained. When the melting temperature is lower than the above range, the powders in the raw materials are difficult to be completely melted, which may easily cause the lead-free glaze obtained to be difficult to form a transparent and uniform frit.

[0019] Preferably, the preparation method of the strong alkali-resistant lead-free glaze for white porcelain includes the following steps: Mix feldspar powder, alumina powder, calcium carbonate powder, dolomite powder, barium carbonate powder, strontium carbonate powder, lithium carbonate powder, boric acid powder, zinc oxide powder, silica powder, borax powder, kaolin powder and magnesium silicate powder in proportion to obtain a mixed powder; Melt the obtained mixed powder at 1500 - 1600 °C and then perform water quenching to obtain the strong alkali-resistant lead-free glaze for white porcelain.

[0020] By adopting the above technical solution, adding magnesium silicate powder to the raw materials and mixing it with other components in the raw materials facilitates improving the workability of the raw material mixture.

[0021] In summary, the present application has the following beneficial effects: 1. Silicon dioxide plays a role in increasing the melting point, increasing the viscosity, reducing the expansion coefficient, improving the mechanical strength and hardness in the glaze, forming complex silicate compounds with the alkaline oxides in the glaze, and these compounds can resist the erosion of various gases, water, acids and alkalis; alumina increases the melting point, increases the viscosity, improves the chemical stability and reduces the tendency of cracking, and can promote the fluidity of the glaze and inhibit the crystallization effect.

[0022] 2. By connecting magnesium silicate powder and titanium dioxide powder with a linker, attaching the magnesium silicate powder outside the titanium dioxide powder, reducing the possibility of agglomeration of titanium dioxide powder in the powder system of the raw materials, improving the dispersibility of titanium dioxide powder, making the obtained lead-free glaze have self-cleaning property and wear resistance during application, and reducing the possibility of wear of the obtained lead-free glaze during the cleaning process.

[0023] 3. Preparing modified titanium dioxide powder by sol-gel method with tetrabutyl titanate and silver nitrate, thus wrapping silver on the surface of titanium dioxide, and forming a "core-shell" structure when the modified titanium dioxide is mixed with magnesium silicate powder, further improving the dispersibility and stability of titanium dioxide powder, making the obtained lead-free glaze have antibacterial properties, and then improving the corrosion resistance of the obtained lead-free glaze, reducing the adverse effects on the applicability of the obtained porcelain. Specific Embodiments

[0024] The following further elaborates the present application in detail with reference to embodiments.

[0025] The detection methods for the alkali resistance, wear resistance, melting temperature range and antibacterial rate of the strong alkali-resistant lead-free glaze for white porcelain prepared in all examples and comparative examples are as follows: 1. Alkali resistance The alkali resistance of the lead-free glaze for white porcelain resistant to strong alkali is detected according to the detection method of the national standard GB / T 3810.13-2016 "Test methods for ceramic tiles - Part 13: Determination of chemical resistance". Detection solution: 100 g / L potassium hydroxide solution. Detection temperature: 20±2°C.

[0026] 2. Abrasion resistance The abrasion resistance of the lead-free glaze for white porcelain resistant to strong alkali is detected according to the detection method of the national standard GB / T 3810.7-2016 "Test methods for ceramic tiles - Part 7: Determination of surface abrasion resistance of glazed tiles".

[0027] 3. Antibacterial rate The antibacterial rate of the lead-free glaze for white porcelain resistant to strong alkali is detected according to the detection method of the industry standard JC∕T 897-2014 "Antibacterial properties of antibacterial ceramic products". Raw materials

[0028] All raw materials in the preparation examples and implementation examples of this application can be obtained commercially. Preparation examples

[0029] Preparation example 1 Modified titanium dioxide powder Preparation example 1.1 A kind of modified titanium dioxide powder is prepared by the following steps: Mix 2 kg of tetrabutyl titanate and 12 kg of absolute ethanol, and then add 2 kg of glacial acetic acid and mix well to obtain a mixed solution A; Mix 6 kg of deionized water and 6 kg of absolute ethanol, and add 1 kg of silver nitrate and mix well to obtain a mixed solution B; Drop the mixed solution B into the mixed solution A drop by drop, and stir until a light yellow transparent sol is formed; Dry the obtained sol at 80°C for 24 h to obtain a gel; Calcine the obtained gel at 650°C for 2 h, cool and crush to obtain the modified titanium dioxide powder.

[0030] Preparation example 1.2 The difference from Preparation example 1.1 is that the addition amount of silver nitrate in Preparation example 1.2 is 2 kg.

[0031] Preparation example 1.3 The difference from Preparation example 1.1 is that the addition amount of silver nitrate in Preparation example 1.3 is 3 kg.

[0032] Preparation example 2 Modified magnesium silicate powder Preparation example 2.1 A kind of modified magnesium silicate powder is prepared by the following steps: After mixing 2 kg of coconut oil and 1 kg of titanium dioxide powder evenly, add 3 kg of magnesium silicate powder and mix evenly to obtain modified magnesium silicate powder.

[0033] Preparation Example 2.2 Different from Preparation Example 2.1, in Preparation Example 2.2, the addition amount of titanium dioxide powder is 2 kg, and the addition amount of magnesium silicate powder is 2 kg.

[0034] Preparation Example 2.3 Different from Preparation Example 2.1, in Preparation Example 2.3, the addition amount of titanium dioxide powder is 3 kg, and the addition amount of magnesium silicate powder is 1 kg.

[0035] Preparation Example 2.4 Different from Preparation Example 2.2, in Preparation Example 2.4, the coconut oil is replaced with an equal amount of avocado oil.

[0036] Preparation Examples 2.5 - 2.7 Different from Preparation Example 2.2, in Preparation Examples 2.5 - 2.7, the titanium dioxide powder is replaced with an equal amount of modified titanium dioxide powder prepared in Preparation Examples 1.1 - 1.3. Examples

[0037] Example 1 Without adding magnesium silicate Example 1.1 A strong - alkali - resistant and lead - free glaze for white porcelain is prepared by the following steps: Mix 37 kg of feldspar powder, 1 kg of alumina powder, 1 kg of calcium carbonate powder, 7 kg of dolomite powder, 4 kg of barium carbonate powder, 1 kg of strontium carbonate powder, 0.5 kg of lithium carbonate powder, 4 kg of boric acid powder, 10 kg of zinc oxide powder, 20 kg of silicon oxide powder, 3 kg of borax powder, and 6 kg of kaolin powder evenly to obtain a mixed powder; Melt the obtained mixed powder at 1500 °C and then perform water quenching to obtain the strong - alkali - resistant and lead - free glaze for white porcelain.

[0038] Examples 1.2 - 1.5 Different from Example 1.1, in Examples 1.2 - 1.5, the raw material ratios and melting temperatures are different. See Table 1 for details.

[0039] Table 1 Raw material ratios and melting temperatures of Examples 1.1 - 1.5

[0040] Comparative Example 1 Different from Example 1.1, in Comparative Example 1, the addition amount of silicon oxide is 0.1 kg.

[0041] Comparative Example 2 Different from Example 1.1, in Comparative Example 2, the addition amount of silicon oxide is 10 kg.

[0042] Comparative Example 3 Differing from Example 1.1, the addition amount of alumina in Comparative Example 3 was 0.1 kg.

[0043] Comparative Example 4 Differing from Example 1.1, the addition amount of alumina in Comparative Example 4 was 5 kg.

[0044] Comparative Example 5 Differing from Example 1.1, the melting temperature in Comparative Example 5 was 900 °C.

[0045] The alkali resistance, abrasion resistance and antibacterial rate of the lead-free glaze for alkali-resistant white porcelain prepared in Examples 1.1 - 1.5 and Comparative Examples 1 - 5 were tested, as shown in Table 2 for details.

[0046] Table 2 Performance test data table of Examples 1.1 - 1.5 and Comparative Examples 1 - 5

[0047] Combined with Table 2, it can be seen that the lead-free glaze for alkali-resistant white porcelain prepared in Examples 1.1 - 1.5 is superior to the lead-free glaze for alkali-resistant white porcelain prepared in Comparative Examples 1 - 5 in terms of alkali resistance, abrasion resistance and antibacterial property. This shows that the raw material ratio and melting temperature selected in Examples 1.1 - 1.10 of this application are beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for alkali-resistant white porcelain.

[0048] Combined with Example 1.1 and Comparative Examples 1 - 2, it was found that the addition amount of silica in Comparative Example 1 was less than that in Example 1.1, and the lead-free glaze for alkali-resistant white porcelain prepared had worse performance in terms of alkali resistance, abrasion resistance and antibacterial property than Example 1.1; the addition amount of silica in Comparative Example 2 was more than that in Example 1.1, and the lead-free glaze for alkali-resistant white porcelain prepared had worse performance in terms of alkali resistance, abrasion resistance and antibacterial property than Example 1.1. This shows that the addition amount of silica selected in Example 1.1 is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for alkali-resistant white porcelain.

[0049] Combined with Example 1.1 and Comparative Examples 3 - 4, it was found that the addition amount of alumina in Comparative Example 3 was less than that in Example 1.1, and the lead-free glaze for alkali-resistant white porcelain prepared had worse performance in terms of alkali resistance, abrasion resistance and antibacterial property than Example 1.1; the addition amount of alumina in Comparative Example 4 was more than that in Example 1.1, and the lead-free glaze for alkali-resistant white porcelain prepared had worse performance in terms of alkali resistance, abrasion resistance and antibacterial property than Example 1.1. This shows that the addition amount of alumina selected in Example 1.1 is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for alkali-resistant white porcelain.

[0050] Combined with Example 1.1 and Comparative Example 5, it was found that the melting temperature in Comparative Example 5 was lower than that in Example 1.1, and the prepared lead-free glaze for white porcelain resistant to strong alkali was inferior to Example 1.1 in terms of alkali resistance, abrasion resistance and antibacterial property. This indicates that the addition amount of the melting temperature selected in Example 1.1 is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for white porcelain resistant to strong alkali.

[0051] In Examples 1.1 - 1.3, the influence of raw material ratio was investigated. It was found that the lead-free glaze for white porcelain prepared in Example 1.2 showed better performance in terms of alkali resistance, abrasion resistance and antibacterial property. This indicates that the raw material ratio selected in Example 1.2 is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for white porcelain resistant to strong alkali.

[0052] Taking Example 1.2 as a control, the influence of melting temperature was investigated in Examples 1.4 - 1.5. It was found that the lead-free glaze for white porcelain prepared in Example 1.4 showed better performance in terms of alkali resistance, abrasion resistance and antibacterial property. This indicates that the melting temperature selected in Example 1.4 is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for white porcelain resistant to strong alkali.

[0053] Example 2 adds magnesium silicate Example 2.1 Different from Example 1.4, 2 kg of magnesium silicate powder is added in Example 2.1.

[0054] Example 2.2 Different from Example 2.1, the addition amount of magnesium silicate powder in Example 2.2 is 3 kg.

[0055] Example 2.3 Different from Example 2.1, the addition amount of magnesium silicate powder in Example 2.3 is 4 kg.

[0056] The lead-free glaze for white porcelain prepared in Examples 2.1 - 2.3 was tested for alkali resistance, abrasion resistance and antibacterial rate. See Table 3 for details.

[0057] Table 3 Performance test data table of Examples 2.1 - 2.3

[0058] As can be seen from Table 3, the white porcelain alkali-resistant lead-free glaze prepared in Examples 2.1 - 2.3 shows better performance in terms of alkali resistance, abrasion resistance, and antibacterial property than the white porcelain alkali-resistant lead-free glaze prepared in Example 1.4. This may be because magnesium silicate is added in Examples 2.1 - 2.3, thus fully improving the workability and dispersibility of each powder material during the raw material process, enabling each powder to be evenly distributed in the white porcelain alkali-resistant lead-free glaze prepared, facilitating the formation of a uniform and stable glaze, and further enhancing the alkali resistance, abrasion resistance, and antibacterial property of the white porcelain alkali-resistant lead-free glaze.

[0059] In Examples 2.1 - 2.3, the influence of the addition amount of magnesium silicate was investigated. The results showed that the white porcelain alkali-resistant lead-free glaze prepared in Example 2.2 exhibited better performance in terms of alkali resistance, abrasion resistance, and antibacterial property. This indicates that the addition amount of magnesium silicate selected in Example 2.2 is beneficial to improving the alkali resistance, abrasion resistance, and antibacterial property of the white porcelain alkali-resistant lead-free glaze.

[0060] In Example 3, modified magnesium silicate powder was added Examples 3.1 - 3.7 Different from Example 2.2, in Examples 3.1 - 3.7, the magnesium silicate powder was replaced with an equal amount of modified magnesium silicate powder prepared in Preparation Examples 2.1 - 2.7.

[0061] The white porcelain alkali-resistant lead-free glaze prepared in Examples 3.1 - 3.7 was tested for alkali resistance, abrasion resistance, and antibacterial rate. See Table 4 for details.

[0062] Table 4 Performance test data table of Examples 3.1 - 3.7

[0063] As can be seen from Table 4, the white porcelain alkali-resistant lead-free glaze prepared in Examples 3.1 - 3.7 shows better performance in terms of alkali resistance, abrasion resistance, and antibacterial property than the white porcelain alkali-resistant lead-free glaze prepared in Example 2.2. This may be because in Examples 3.1 - 3.7, magnesium silicate was replaced with modified magnesium silicate, thereby introducing titanium dioxide into the raw materials and further enhancing the alkali resistance, abrasion resistance, and antibacterial rate of the white porcelain alkali-resistant lead-free glaze.

[0064] In Examples 3.1 - 3.3, the influence of the raw material ratio of modified magnesium silicate was investigated. The results showed that the white porcelain alkali-resistant lead-free glaze prepared in Example 3.2 exhibited better performance in terms of alkali resistance, abrasion resistance, and antibacterial property. This indicates that the raw material ratio of modified magnesium silicate selected in Example 3.2 is beneficial to improving the alkali resistance, abrasion resistance, and antibacterial property of the white porcelain alkali-resistant lead-free glaze.

[0065] Taking Example 3.2 as a control, Example 3.4 investigated the influence of the binder. The results showed that in Example 3.4, coconut oil was replaced with an equal amount of avocado oil, and the prepared lead-free glaze for white porcelain resistant to strong alkali was inferior to that of Example 3.2 in terms of alkali resistance, abrasion resistance and antibacterial property. This indicates that the selection of coconut oil as the binder in Example 3.2 is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for white porcelain resistant to strong alkali.

[0066] Taking Example 3.2 as a control, Examples 3.5 - 3.7 investigated the influence of modified titanium dioxide. The results showed that the prepared lead-free glaze for white porcelain resistant to strong alkali in Examples 3.5 - 3.7 was superior to that of Example 3.2 in terms of alkali resistance, abrasion resistance and antibacterial property. This indicates that the preparation of modified magnesium silicate by modified titanium dioxide is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for white porcelain resistant to strong alkali.

[0067] Examples 3.5 - 3.7 investigated the influence of the raw material ratio of modified titanium dioxide. The results showed that the prepared lead-free glaze for white porcelain resistant to strong alkali in Example 3.6 was superior in terms of alkali resistance, abrasion resistance and antibacterial property. This indicates that the selected raw material ratio of modified titanium dioxide in Example 3.6 is beneficial to improving the alkali resistance, abrasion resistance and antibacterial property of the lead-free glaze for white porcelain resistant to strong alkali According to the detection method of the industry standard QB / T 1546 - 2016 "Determination Method for Melting Temperature Range of Ceramic Glazes", the melting temperature ranges of the lead-free glazes for white porcelain resistant to strong alkali prepared in Examples 1 - 3 were detected. It was found that the melting temperature ranges of the lead-free glazes for white porcelain resistant to strong alkali prepared in Examples 1 - 3 were all 1080 - 1260 °C.

[0068] This specific embodiment is only an interpretation of the present application and is not a limitation thereof. Those skilled in the art can make modifications to this embodiment without creative contributions according to their needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A strong alkali-resistant lead-free glaze for white porcelain, characterized in that: The invention comprises the following raw materials in parts by weight: 37-41 parts of feldspar powder, 0.5-1 parts of alumina powder, 1-3 parts of calcium carbonate powder, 3-7 parts of dolomite powder, 4-8 parts of barium carbonate powder, 0.5-1 parts of strontium carbonate powder, 0.5-1.5 parts of lithium carbonate powder, 3-4 parts of boric acid powder, 10-13 parts of zinc oxide powder, 15-20 parts of silicon oxide powder, 3-6 parts of borax powder, and 3-6 parts of kaolin powder.

2. The alkali-resistant lead-free glaze for white porcelain according to claim 1, characterized in that: The raw materials also include 2-4 parts of magnesium silicate powder.

3. The alkali-resistant lead-free glaze for white porcelain according to claim 2, characterized in that: The magnesium silicate powder is modified magnesium silicate, and the modified magnesium silicate powder is prepared by mixing magnesium silicate powder, a connecting agent and titanium dioxide powder in a weight ratio of (1-3):2:(1-3). The modified magnesium silicate powder is prepared by the following steps: After the connector and titanium dioxide powder are mixed in proportion, magnesium silicate powder is added in proportion and mixed to obtain modified magnesium silicate powder.

4. The alkali-resistant lead-free glaze for white porcelain according to claim 3, characterized in that: The linking agent is coconut oil.

5. The alkali-resistant lead-free glaze for white porcelain according to claim 4, characterized in that: The titanium dioxide powder is modified titanium dioxide powder, and the modified titanium dioxide powder is prepared from tetrabutyl titanate and silver nitrate in a weight ratio of 2: (1-3).

6. The alkali-resistant lead-free glaze for white porcelain according to claim 5, characterized in that: The modified titanium dioxide powder is prepared by the following steps: Tetrabutyl titanate and anhydrous ethanol are mixed at a weight ratio of 1: (6±1), and then glacial acetic acid is added and mixed. The weight ratio of tetrabutyl titanate to glacial acetic acid is 1: (1±0.5), to obtain a mixed solution A; Deionized water and anhydrous ethanol are mixed in a weight ratio of 3:(3±1), and silver nitrate is added and mixed to prepare a mixed solution B; Add mixed solution B dropwise into mixed solution A and stir until a light yellow transparent sol is formed; The prepared sol was dried at 80±5°C for 24±2h to obtain a gel; The prepared gel was calcined at 650±50°C for 2±1h, cooled and crushed to obtain modified titanium dioxide powder.

7. A method for preparing the alkali-resistant lead-free glaze for white porcelain according to claim 1, characterized in that: The following steps are involved: Mix feldspar powder, alumina powder, calcium carbonate powder, dolomite powder, barium carbonate powder, strontium carbonate powder, lithium carbonate powder, boric acid powder, zinc oxide powder, silicon oxide powder, borax powder and kaolin powder according to weight ratio to obtain mixed powder; The prepared mixed powder is melted at 1500-1600°C and quenched with water to obtain a strong alkali-resistant lead-free glaze for white porcelain.

8. A method for preparing the alkali-resistant lead-free glaze for white porcelain according to any one of claims 2 to 6, characterized in that: The following steps are involved: Mix feldspar powder, alumina powder, calcium carbonate powder, dolomite powder, barium carbonate powder, strontium carbonate powder, lithium carbonate powder, boric acid powder, zinc oxide powder, silicon oxide powder, borax powder, kaolin powder and magnesium silicate powder according to proportion to obtain a mixed powder; The prepared mixed powder is melted at 1500-1600°C and quenched with water to obtain a strong alkali-resistant lead-free glaze for white porcelain.

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