A method for preparing wear-resistant and corrosion-resistant glaze for building and sanitary ceramics

Abstract

This invention discloses a method for preparing a wear-resistant and corrosion-resistant glaze for building and sanitary ceramics. Using natural minerals as the main component, by adjusting the raw material composition and process, the method reduces the amount of zirconium silicate reinforcing particles while improving the acid corrosion resistance of the base glass layer of the glaze and the two-phase compatibility between the base glass layer and the zirconium silicate reinforcing particles, ultimately obtaining a ceramic glaze layer with excellent wear resistance and corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of building and sanitary ceramic glaze technology, and in particular to a method for preparing a wear-resistant and corrosion-resistant glaze for building and sanitary ceramics. Background Technology

[0002] Building and sanitary ceramics (such as ceramic tiles and sanitary ware) have extremely stringent requirements for the performance of their surface glaze. While meeting decorative requirements (high whiteness, high gloss, smoothness), they also need to withstand repeated and long-term friction, corrosion, and cleaning, often demanding long-lasting high hardness and wear resistance. Existing technologies mainly address this through two approaches: First, adding high-hardness, wear-resistant particles such as zirconium silicate and alumina to enhance glaze hardness. Second, some research reduces the sodium content of the glaze and introduces multi-metal oxides to improve the chemical stability of the glassy region of the glaze. While adding high-hardness, wear-resistant particles does increase hardness in the early stages of product use, this method does not consider the relationship between the base glass layer and the reinforcing particles. In reality, during glaze formation, the physical properties of the base glass layer and the reinforcing particles are compatible, resulting in micro-cracks at their contact edges. These cracks expand during repeated use and cleaning, especially under the corrosive effects of acids and alkalis in cleaning agents, potentially causing pitting or partial peeling of the glaze, leading to a decrease in stain resistance over time. Essentially, these technical solutions fail to address the interaction between the base glass layer and reinforcing particles (zirconium silicate, alumina, etc.), thus the presence of microcracks is unavoidable; that is, they cannot fundamentally solve the problem of microcracks and their propagation. Furthermore, existing testing and characterization methods can only statically characterize the wear and corrosion resistance of products, therefore they cannot effectively demonstrate and verify the decline in wear and corrosion resistance caused by crack propagation over time. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a wear-resistant and corrosion-resistant glaze for building and sanitary ceramics. Using natural minerals as the main body, by adjusting the raw material composition and process, the acid corrosion resistance of the base glass layer of the glaze is improved while reducing the amount of reinforcing particles zirconium silicate, and the two-phase compatibility between the base glass layer and the reinforcing particles zirconium silicate is improved, ultimately obtaining a ceramic glaze layer with excellent wear resistance and corrosion resistance.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] This invention provides a method for preparing a wear-resistant and corrosion-resistant glaze for building and sanitary ceramics. The raw material composition of the wear-resistant and corrosion-resistant glaze is as follows: albite 2-10 wt%, potassium feldspar 4-18 wt%, quartz 15-30 wt%, calcined kaolin 8-20 wt%, wollastonite 2-10 wt%, limestone 8-18 wt%, zirconium silicate 5-10 wt%, alumina 0-5 wt%, zinc oxide 0.5-1 wt%, calcined talc 2-9 wt%, and barium carbonate 0.2-1 wt%. The preparation method includes the following steps:

[0006] (1) Dissolve carboxymethyl cellulose in water, the amount of carboxymethyl cellulose being 0.1 to 1 wt% of the total raw material composition; then add zirconium silicate, ball mill for 0.5 to 2 h, then add the remaining raw material composition, continue ball milling for 0.5 to 2 h, and the resulting slurry is aged to obtain glaze slurry;

[0007] (2) The glaze slurry is applied to the surface of the unglazed body to obtain a glaze layer with a thickness of 0.12 to 0.18 mm. After drying, it is sintered at a temperature of 1120 to 1250 °C for 15 to 25 min to obtain a wear-resistant and corrosion-resistant glaze.

[0008] The wear-resistant and corrosion-resistant glaze is judged by the wear-resistant and corrosion-resistant ability of the glaze surface over time. That is, the hardness is obtained by plotting the number of days as the abscissa and the microhardness as the ordinate, and obtaining the decay curve of hardness with the corrosion time of acid or alkali solution at a temperature of 25-100℃. The inverse value of the maximum slope of the tangent of the decay curve is taken, and the absolute value of the inverse value is taken as the corrosion resistance coefficient. The acid corrosion resistance coefficient of the wear-resistant and corrosion-resistant glaze is greater than 0.03, which is 1 to 3 times higher, and the alkali corrosion resistance coefficient is greater than 0.04, which is 3 to 4 times higher.

[0009] In the above scheme, the concentration of the acid solution of the present invention is 10. -6 ~12 mol / L, the concentration of the alkaline solution is 10 -6 ~6 mol / L.

[0010] Furthermore, in step (1) of the present invention, ball milling is performed at a mass ratio of material:ball:water = 1:2-3:0.5-1.5; the aging time is 24-45 h.

[0011] The present invention has the following beneficial effects:

[0012] (1) The technical innovation of this invention lies in increasing the amount of calcined talc and the magnesium content, which firstly reduces the thermal expansion coefficient of the base glass, making it close to that of the zirconium silicate reinforcing particles, thereby reducing the internal stress on the glass and reducing microcracks, thus preventing the propagation of cracks caused by chemical corrosion from the source. Secondly, based on the suppression effect, the network structure of the glaze glass is enhanced, inhibiting the dissolution of sodium ions and reducing the rate of chemical corrosion (improving corrosion resistance).

[0013] (2) Unlike the traditional method of improving the adhesion of glazes by using carboxymethyl cellulose and ball milling for glaze preparation in a single batching process, this invention utilizes the dispersing activity of carboxymethyl cellulose and optimizes the glaze preparation process by changing the single batching ball milling to a two-stage batching ball milling. The first batching ball milling only achieves the dispersion of the reinforcing particles zirconium silicate: by utilizing the steric hindrance effect of carboxymethyl cellulose, the reinforcing particles zirconium silicate are highly dispersed and do not agglomerate; then, on this basis, a second batching ball milling is carried out, that is, other materials are added, thereby ensuring the uniformity of the dispersion of the reinforcing particles zirconium silicate in the glaze, providing a basis for the uniformity of the glaze surface strength.

[0014] (3) By adjusting the formula, the interaction between the glaze glass and the reinforcing particles is improved, and a durable wear-resistant and corrosion-resistant glaze is finally obtained, which has a large acid corrosion resistance coefficient and alkali corrosion resistance coefficient.

[0015] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings:

[0016] Figure 1 These are the hardness variation curves of the samples in Example 2 and Comparative Example 2 of the present invention as a function of acid corrosion time ((a): Example 2; (b): Comparative Example 2).

[0017] Figure 2 These are the hardness variation curves of the samples from Example 2 and Comparative Example 1 of this invention as a function of alkali corrosion time ((a): Example 2; (b): Comparative Example 1).

[0018] Figure 3 These are SEM images of the samples from Example 2 and Comparative Example 1 after 2 days of acid etching ((a): Example 2; (b): Comparative Example 1). Detailed Implementation

[0019] This invention discloses a method for preparing a wear-resistant and corrosion-resistant glaze for building and sanitary ceramics. The raw material composition of the wear-resistant and corrosion-resistant glaze is as follows: albite 2-10 wt%, potassium feldspar 4-18 wt%, quartz 15-30 wt%, calcined kaolin 8-20 wt%, wollastonite 2-10 wt%, limestone 8-18 wt%, zirconium silicate 5-10 wt%, alumina 0-5 wt%, zinc oxide 0.5-1 wt%, calcined talc 2-9 wt%, and barium carbonate 0.2-1 wt%. The preparation method comprises the following steps:

[0020] (1) Dissolve carboxymethyl cellulose in water, with the amount of carboxymethyl cellulose being 0.5 wt% of the total amount of the above raw materials; then add zirconium silicate, and ball mill at a mass ratio of material:ball:water = 1:2-3:0.5-1.5 for 0.5-2 h, then add the remaining raw materials and continue ball milling for 0.5-2 h. The resulting slurry is aged for 24-45 h to obtain a glaze slurry.

[0021] (2) Apply the above glaze slurry to the surface of the unglazed body to obtain a glaze layer with a thickness of 0.12 to 0.18 mm. After drying, sinter at 1120 to 1250 °C for 15 to 25 min to obtain a wear-resistant and corrosion-resistant glaze.

[0022] Comparative Example 1:

[0023] This comparative example adjusts the raw material composition based on Example 1, so that the MgO content in the glaze is 48.7% of that in Example 1, while the ZrO2 (reinforcing particles) content is close. The preparation process uses a single batching, that is, all raw materials are added to the ball mill jar for ball milling at once, and the remaining steps are the same as in Example 1.

[0024] Comparative Example 2:

[0025] The raw material composition of this comparative example is the same as that of Example 2. The preparation process adopts one-time batching, that is, all raw materials are added to the ball mill jar for ball milling at one time, and the remaining steps are the same as those of Example 2.

[0026] The raw material composition of the wear-resistant and corrosion-resistant glazes of various embodiments of the present invention, as well as the comparative examples, is shown in Table 1; the chemical composition of the glazes is shown in Table 2.

[0027] Table 1. Raw material composition (wt%) of wear-resistant and corrosion-resistant glazes in embodiments of the present invention and comparative examples.

[0028]

[0029] Table 2 Chemical composition (wt%) of glazes in the embodiments / comparative examples of the present invention

[0030]

[0031] The process parameters of the various embodiments and comparative examples of the present invention are shown in Table 3.

[0032] Table 3 Process parameters of embodiments / comparative examples of the present invention

[0033]

[0034] Performance testing:

[0035] 1. The samples obtained in Embodiment 1 and Comparative Example 1 of the present invention, such as Figure 3As shown, the white area represents the added zirconium silicate particles as a reinforcing phase. Zirconium silicate does not react with the glaze matrix (glass) to form glass; instead, it exists independently to enhance the wear resistance of the glaze surface. The EDS elemental analysis results for the pure glass area (the area without zirconium silicate particles, i.e., the area without white particles) are shown in Table 4.

[0036] Table 4. EDS elemental analysis results of the samples obtained in Example 1 and Comparative Example 1 of this invention.

[0037]

[0038] Table 4 Results Analysis: Example 1 has a higher magnesium ion content, which is beneficial for enhancing the network structure: compared to the high-calcium glass in Comparative Example 1, its coefficient of thermal expansion is (9.5 × 10⁻⁶). -6 ℃ -1 In Example 1, the glaze layer has a high magnesium content, while magnesium glass has a lower coefficient of thermal expansion (5×10). -6 ℃ -1 ), with reinforcing particles zirconium silicate (4.5×10 -6 ℃ -1 The proximity of the two components facilitates their combination, reduces microcracks generated during the preparation process, and thus avoids or reduces crack propagation during acid and alkali corrosion.

[0039] 2. Acid / alkali corrosion test

[0040] (2-1) The ceramic samples from Example 2 and Comparative Example 2 were subjected together at a temperature of 40°C and a concentration of 10... -3 The sample was soaked in a mol / L hydrochloric acid solution for 10 days. During this period, one wear-resistant and corrosion-resistant glaze sample was taken out every 1-4 days, washed with deionized water, and its microhardness was tested. A hardness decay curve was obtained by plotting the number of days on the x-axis and microhardness on the y-axis. The reciprocal of the maximum slope of the tangent line of the decay curve was taken, and the absolute value of this reciprocal (defined as the corrosion resistance coefficient) was used as the determination of corrosion resistance. The test results of the wear-resistant and corrosion-resistant glaze sample obtained in Example 2 and the sample in Comparative Example 2 are as follows: Figure 1 a, b, and Table 5 are shown.

[0041] (2-2) The ceramic sample from Example 2 and Comparative Example 1 were subjected to a temperature of 40°C and a concentration of 10... -4The sample was immersed in a mol / L sodium hydroxide solution for 10 days. During this period, one wear-resistant and corrosion-resistant glaze sample was taken out every 1-4 days, washed with deionized water, and its microhardness was tested. A hardness decay curve was obtained by plotting the number of days on the x-axis and microhardness on the y-axis. The reciprocal of the maximum slope of the tangent line of the decay curve was taken, and the absolute value of this reciprocal (defined as the corrosion resistance coefficient) was used as the determination of corrosion resistance. The test results of the wear-resistant and corrosion-resistant glaze sample obtained in Example 2 and the sample in Comparative Example 1 are as follows: Figure 2 a, b, and Table 5 are shown.

[0042] Table 5. Corrosion resistance coefficient results of the embodiments and comparative samples of the present invention.

[0043]

[0044] * The concentration of the acid / base solution is mol / L. Example 1 and Comparative Example 2 use dilute hydrochloric acid solution, while Example 2 and Comparative Example 1 use sodium hydroxide solution.

[0045] The results show that:

[0046] Example 2 and Comparative Example 2 have the same formulation composition, but use different batching processes. The former uses a two-stage batching process, while the latter uses a one-stage batching process. The corrosion resistance coefficient of Example 2 is as high as 0.052, which is nearly three times that of Comparative Example 2 (0.018), demonstrating excellent acid corrosion resistance.

[0047] Example 2 uses a two-stage batching process and has a higher magnesium content, while Comparative Example 1 uses a one-stage batching process and has a lower magnesium content. The corrosion resistance coefficient of Example 2 reaches 0.089, which is nearly 3.5 times that of Comparative Example 1 (0.026), demonstrating excellent resistance to alkali corrosion.

[0048] (2-3) The ceramic sample from Example 3 and Comparative Example 1 were subjected to a temperature of 25°C and a concentration of 10... -3 After soaking in a mol / L hydrochloric acid solution for 2 days, the samples were removed and rinsed with deionized water. Scanning electron microscope (SEM) images of the sample surfaces from Example 3 and Comparative Example 1 are shown below. Figure 3 As shown in a and b.

[0049] The results showed that Example 3, which used a two-stage batching process, had a higher magnesium content and a lower content of zirconium silicate reinforcing particles, while Comparative Example 1, which used a one-stage batching process, had a lower magnesium content and a higher content of zirconium silicate reinforcing particles. The zirconium silicate reinforcing particles (white particles, red arrows) in Example 3 had significantly better dispersibility than those in Comparative Example 1. After acid etching, Example 3 showed no visible changes, while Comparative Example 1 showed peeling and dissolution pits (yellow arrows).

Claims

1. A method for preparing a wear-resistant and corrosion-resistant glaze for building and sanitary ceramics, characterized in that: The raw material composition of the wear-resistant and corrosion-resistant glaze is as follows: albite 2-10 wt%, potassium feldspar 4-18 wt%, quartz 15-30 wt%, calcined kaolin 8-20 wt%, wollastonite 2-10 wt%, limestone 8-18 wt%, zirconium silicate 5-10 wt%, alumina 0-5 wt%, zinc oxide 0.5-1 wt%, calcined talc 2-9 wt%, and barium carbonate 0.2-1 wt%. The preparation method includes the following steps: (1) Dissolve carboxymethyl cellulose in water, the amount of carboxymethyl cellulose being 0.1 to 1 wt% of the total raw material composition; then add zirconium silicate, ball mill for 0.5 to 2 h, then add the remaining raw material composition, continue ball milling for 0.5 to 2 h, and the resulting slurry is aged to obtain glaze slurry; (2) The glaze slurry is applied to the surface of the unglazed body to obtain a glaze layer with a thickness of 0.12 to 0.18 mm. After drying, it is sintered at a temperature of 1120 to 1250 °C for 15 to 25 min to obtain a wear-resistant and corrosion-resistant glaze. The wear-resistant and corrosion-resistant glaze is judged by the wear-resistant and corrosion-resistant ability of the glaze surface over time. That is, the hardness is obtained by plotting the number of days as the abscissa and the microhardness as the ordinate, and obtaining the decay curve of hardness with the corrosion time of acid or alkali solution at a temperature of 25-100℃. The inverse value of the maximum slope of the tangent of the decay curve is taken, and the absolute value of the inverse value is taken as the corrosion resistance coefficient. The acid corrosion resistance coefficient of the wear-resistant and corrosion-resistant glaze is greater than 0.03, which is 1 to 3 times higher, and the alkali corrosion resistance coefficient is greater than 0.04, which is 3 to 4 times higher.

2. The method for preparing wear-resistant and corrosion-resistant glaze for building and sanitary ceramics according to claim 1, characterized in that: The concentration of the acid solution is 10. -6 ~12 mol / L, the concentration of the alkaline solution is 10 -6 ~6 mol / L.

3. The method for preparing wear-resistant and corrosion-resistant glaze for building and sanitary ceramics according to claim 1, characterized in that: In step (1), ball milling is performed at a mass ratio of material:ball:water = 1:2-3:0.5-1.5; the aging time is 24-45 hours.

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