A high-quality ceramic glaze for sanitary ceramics and a preparation method thereof

Abstract

The present invention discloses a high-quality ceramic glaze for sanitary ceramics and a preparation method thereof. The ceramic glaze comprises, by weight, 15-23% potassium feldspar, 4-10% sodium feldspar, 28-34% quartz, 1-4% aluminum oxide, 8-14% calcite, 4-8% dolomite, 4-8% burned kaolin, 6-8% wollastonite, 2-3% zinc oxide, 7-10% zirconium silicate, and 2-3% boron frit. While the present invention reduces the use of zirconium silicate in the formula, by precisely adjusting the silicon-aluminum ratio and introducing quartz particles of a specific composition, the glaze surface hardness is comparable to that of conventional formulas. Even while reducing the use of potentially radioactive ingredients, the product still provides good scratch resistance and a long service life, thereby maintaining normal use and aesthetics. By reducing the amount of zirconium silicate used, the glaze formula reduces production costs by approximately 20%, achieving energy conservation and consumption reduction.

Description

Technical Field

[0001] The present invention relates to the technical field of sanitary ceramic preparation, in particular to a high-quality ceramic glaze for sanitary ceramic and a preparation method thereof. Background Art

[0002] As people's quality of life improves, consumers have increasingly stringent requirements for sanitary ceramic glazes. They not only expect the glaze to be smooth, delicate, and white, but also place higher standards on environmental friendliness. To achieve stable glaze quality and the required whiteness, existing ceramic white glazes usually add a certain amount of zirconium silicate. Zirconium silicate has the function of whitening and enhancing hardness, and is therefore widely used in ceramic glazes.

[0003] However, zircon, the main raw material of zirconium silicate, often contains radioactive elements, which leads to the presence of radioactive impurities in the prepared zirconium silicate. These impurities are difficult to remove within the ZrSiO4 structure of zirconium silicate, posing potential risks to human health and the environment. Therefore, in the actual preparation process, reducing the amount of zirconium silicate used has become a problem to be solved.

[0004] Based on this, a high-quality ceramic glaze for sanitary ceramics and a preparation method thereof are needed. Summary of the Invention

[0005] To achieve the above object, the present invention provides the following solution: a high-quality ceramic glaze for sanitary ceramics, the ceramic glaze comprising, by weight percentage:

[0006] Potassium feldspar: 15-23%, sodium feldspar: 4-10%, quartz: 28-34%, alumina: 1-4%, calcite: 8-14%, dolomite: 4-8%, burned kaolin: 4-8%, wollastonite: 6-8%, zinc oxide: 2-3%, zirconium silicate: 7-10%, boron frit: 2-3%;

[0007] The boron frit has a melting temperature of 700-850°C, contains 7-10% B2O3, a Si / Al ratio of 3-3.3, and 8-10% CaO+MgO, and contains no alkali metal elements. The boron frit is fired in a tunnel kiln at 1200°C, exhibiting a phase-separated milky white color, and is introduced into glaze formulations to increase the whiteness of the glaze surface.

[0008] The particle size distribution of the zirconium silicate is: D[4,3]5-10μm, ≤2μm accounts for 55-65%, ≤10μm accounts for 75-85%, ≤20μm accounts for 85-95%, and the particle grading of the quartz is 1-3% residual on a 100-mesh sieve, 80-90% residual on a 250-mesh sieve, and 90-95% residual on a 350-mesh sieve.

[0009] In addition, the present invention provides a method for preparing high-quality ceramic glaze for sanitary ceramics, comprising the following preparation steps:

[0010] Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio;

[0011] Step 2: Mix the above-mentioned accurately weighed raw materials with an appropriate amount of water and wet-grind them using a ball mill for 4 to 6 hours until the average particle size of the slurry is less than 10 μm;

[0012] Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities;

[0013] Step 4: Add appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the slurry after adjustment needs to be controlled between 6.5 and 7.5.

[0014] Step 5: Apply the glaze evenly on the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled within 0.85-1.0 mm.

[0015] Step 6: Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, use natural gas as fuel, and set the firing cycle to 15 to 20 hours. Raise the temperature to 1197 to 1203°C and maintain the temperature for 30 to 40 minutes for a sintering cycle.

[0016] Further preferably, the glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.3~0.5MPa, so that the glaze is evenly distributed on the surface of the green body. At the same time, during the glazing process, the glaze should be kept at room temperature of 20℃~25℃, so that the glaze can better adhere to the surface of the green body after spraying.

[0017] Further preferably, during the sintering process, a multi-stage heating curve is adopted, with the initial heating rate controlled at 100°C / hour until the temperature reaches 800°C, then the heating rate is increased to 170°C / hour until the temperature reaches 1100°C, and finally the heating rate is reduced to 50°C / hour until the maximum temperature reaches 1197~1203°C.

[0018] Further preferably, in the slurry preparation in step 4, the added dispersant is sodium polyacrylate, and the added proportion accounts for 0.1% to 0.5% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry.

[0019] Further preferably, in the slurry preparation in step 4, the flow aid used is sodium carboxymethyl cellulose, and the addition ratio accounts for 0.5% to 1.0% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry.

[0020] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0021] 1. The white glaze formula of the present invention improves the radioactivity index of ceramic products by significantly reducing the amount of zirconium silicate used. Compared with traditional formulas, the content of radioactive impurities in this formula is effectively controlled, making the product more in line with green environmental protection standards.

[0022] 2. The present invention reduces the use of zirconium silicate in the formula, but ensures that the hardness of the glaze is comparable to that of the traditional formula by precisely adjusting the silicon-aluminum ratio and introducing quartz particles of a specific composition. Even when reducing ingredients with potential radioactive risks, the product can still provide good scratch resistance and service life, thus not affecting the normal use and appearance of the product.

[0023] 3. The glaze formula of the present invention reduces the amount of zirconium silicate used, thereby reducing production costs by about 20%, thereby achieving the purpose of energy saving and consumption reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 Schematic diagram of an embodiment

[0026] Figure 2 The radioactive detection instrument of the embodiment;

[0027] Figure 3 It is an instrument for detecting color difference and whiteness of the embodiment. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example A1

[0031] like Figure 1-3 As shown, a high-quality ceramic glaze for sanitary ceramics in this embodiment comprises, by weight percentage:

[0032] Potassium feldspar: 23%, sodium feldspar: 4%;

[0033] Quartz: 28%, with a particle size distribution of 2% on a 100-mesh sieve, 85% on a 250-mesh sieve, and 92% on a 350-mesh sieve;

[0034] Alumina: 1.5%, calcite: 11%, dolomite: 7%, burned kaolin: 6%, wollastonite: 8%, zinc oxide: 2.5%;

[0035] Zirconium silicate: 9%, with a particle size distribution of D[4,3]8μm, 60% of which are ≤2μm, 80% of which are ≤10μm, and 90% of which are ≤20μm.

[0036] In addition, the present invention provides a method for preparing high-quality ceramic glaze for sanitary ceramics, comprising the following preparation steps:

[0037] Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio;

[0038] Step 2: Mix the above-mentioned raw materials with an appropriate amount of water and wet-grind them using a ball mill for 5 hours until the average particle size of the slurry is less than 10 μm;

[0039] Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities;

[0040] Step 4: Add an appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the adjusted slurry needs to be controlled at 7.0; the added dispersant is sodium polyacrylate, and the addition ratio accounts for 0.3% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry. The flow aid used is sodium carboxymethyl cellulose, and the addition ratio accounts for 0.7% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry;

[0041] Step 5: Apply the glaze evenly to the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled at 0.9 mm. The glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.4 MPa to make the glaze evenly distributed on the surface of the body. At the same time, during the glazing process, the glaze should be kept at room temperature of 22°C so that the glaze adheres better to the surface of the body after spraying.

[0042] Step 6. Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, the fuel gas to natural gas, the firing cycle to 18 hours, heat to 1200°C, maintain the temperature for 35 minutes for one sintering. During the sintering process, a multi-stage heating curve is adopted. The initial heating rate is controlled at 100°C / hour until the temperature reaches 800°C, then the heating rate is increased to 170°C / hour until the temperature reaches 1100°C, and finally the heating rate is reduced to 50°C / hour until the highest temperature reaches 1203°C.

[0043] Example A2

[0044] The ceramic glaze comprises, by weight percentage:

[0045] Potassium feldspar: 23%, sodium feldspar: 4%;

[0046] Quartz: 28.5%, with a particle size distribution of 2% on a 100-mesh sieve, 85% on a 250-mesh sieve, and 93% on a 350-mesh sieve;

[0047] Alumina: 2%, calcite: 11%, dolomite: 7%, burned kaolin: 6%, wollastonite: 8%, zinc oxide: 2.5%;

[0048] Zirconium silicate: 8%, with a particle size distribution of D[4,3]9 μm, 58% of which are ≤2 μm, 78% of which are ≤10 μm, and 88% of which are ≤20 μm.

[0049] In addition, the present invention provides a method for preparing high-quality ceramic glaze for sanitary ceramics, comprising the following preparation steps:

[0050] Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio;

[0051] Step 2: Mix the above-mentioned raw materials with an appropriate amount of water and wet-grind them using a ball mill for 5 hours until the average particle size of the slurry is less than 10 μm;

[0052] Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities;

[0053] Step 4: Add an appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the adjusted slurry needs to be controlled at 7.0; the added dispersant is sodium polyacrylate, and the addition ratio accounts for 0.3% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry. The flow aid used is sodium carboxymethyl cellulose, and the addition ratio accounts for 0.8% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry;

[0054] Step 5: Apply the glaze evenly to the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled at 0.9 mm. The glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.4 MPa to make the glaze evenly distributed on the surface of the body. At the same time, during the glazing process, the glaze should be kept at room temperature of 22°C so that the glaze adheres better to the surface of the body after spraying.

[0055] Step 6. Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, the fuel gas to natural gas, the firing cycle to 18 hours, heat to 1200°C, maintain the temperature for 35 minutes for one sintering. During the sintering process, a multi-stage heating curve is adopted. The initial heating rate is controlled at 100°C / hour until the temperature reaches 800°C, then the heating rate is increased to 170°C / hour until the temperature reaches 1100°C, and finally the heating rate is reduced to 50°C / hour until the highest temperature reaches 1203°C.

[0056] Example A3

[0057] The ceramic glaze comprises, by weight percentage:

[0058] Potassium feldspar: 19%, sodium feldspar: 6%;

[0059] Quartz: 30%, with a particle size distribution of 2% on a 100-mesh sieve, 82% on a 250-mesh sieve, and 90% on a 350-mesh sieve;

[0060] Alumina: 2.5%, calcite: 12%, dolomite: 7%, burned kaolin: 7%, wollastonite: 7%, zinc oxide: 2.5%;

[0061] Zirconium silicate: 7%, with a particle size distribution of D[4,3]5μm, ≤2μm accounting for 57%, ≤10μm accounting for 76%, and ≤20μm accounting for 86%.

[0062] In addition, the present invention provides a method for preparing high-quality ceramic glaze for sanitary ceramics, comprising the following preparation steps:

[0063] Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio;

[0064] Step 2: Mix the above-mentioned raw materials with an appropriate amount of water and wet-grind them using a ball mill for 5 hours until the average particle size of the slurry is less than 10 μm;

[0065] Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities;

[0066] Step 4: Add an appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the adjusted slurry needs to be controlled at 6.8; the added dispersant is sodium polyacrylate, and the addition ratio accounts for 0.3% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry. The flow aid used is sodium carboxymethyl cellulose, and the addition ratio accounts for 0.6% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry;

[0067] Step 5: Apply the glaze evenly to the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled at 0.9 mm. The glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.4 MPa to make the glaze evenly distributed on the surface of the body. At the same time, during the glazing process, the glaze should be kept at room temperature of 22°C so that the glaze adheres better to the surface of the body after spraying.

[0068] Step 6. Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, use natural gas as the fuel gas, and fire for 18 hours. Raise the temperature to 1200°C and maintain the temperature for 35 minutes for sintering. During the sintering process, adopt a multi-stage heating curve. The initial heating rate is controlled at 50°C / hour until the temperature reaches 800°C, and then increase the heating rate to 100°C / hour until the maximum temperature reaches 1200°C.

[0069] Example A4

[0070] The ceramic glaze comprises, by weight percentage:

[0071] Potassium feldspar: 18%, sodium feldspar: 6%;

[0072] Quartz: 30%, with a particle size distribution of 2% on a 100-mesh sieve, 85% on a 250-mesh sieve, and 90% on a 350-mesh sieve;

[0073] Alumina: 2.5%, calcite: 11%, dolomite: 7%, burned kaolin: 7%, wollastonite: 7%, zinc oxide: 2.5%;

[0074] Zirconium silicate: 7%, with a particle size distribution of D[4,3]6μm, ≤2μm accounting for 65%, ≤10μm accounting for 85%, and ≤20μm accounting for 85%;

[0075] Boron frit: 2%, with a melting temperature of 700°C, containing 7% B2O3, a Si / Al ratio of 3, and a CaO+MgO percentage of 10%, and containing no alkali metal elements.

[0076] In addition, the present invention provides a method for preparing high-quality ceramic glaze for sanitary ceramics, comprising the following preparation steps:

[0077] Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio;

[0078] Step 2: Mix the above-mentioned raw materials with an appropriate amount of water and wet-grind them using a ball mill for 4 hours until the average particle size of the slurry is less than 10 μm;

[0079] Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities;

[0080] Step 4: Add appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the slurry after adjustment needs to be controlled at 7.5;

[0081] The added dispersant is sodium polyacrylate, and the added ratio accounts for 0.2% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry. The added flow aid is sodium carboxymethyl cellulose, and the added ratio accounts for 0.5% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry;

[0082] Step 5: Apply the glaze evenly to the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled at 0.85 mm. The glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.3 MPa to make the glaze evenly distributed on the surface of the body. At the same time, during the glazing process, the glaze should be kept at room temperature of 20°C so that the glaze adheres better to the surface of the body after spraying.

[0083] Step 6. Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, the fuel gas to natural gas, the firing cycle to 15 hours, raise the temperature to 1197°C, maintain the temperature for 30 minutes for one sintering. During the sintering process, a multi-stage heating curve is adopted. The initial heating rate is controlled at 100°C / hour until the temperature reaches 800°C, then increase the heating rate to 170°C / hour until the temperature reaches 1100°C, and finally reduce the heating rate to 50°C / hour until the highest temperature reaches 1203°C.

[0084] Example A5

[0085] The ceramic glaze comprises, by weight percentage:

[0086] Potassium feldspar: 18%, sodium feldspar: 6%;

[0087] Quartz: 30%, with a particle size distribution of 3% on a 100-mesh sieve, 90% on a 250-mesh sieve, and 95% on a 350-mesh sieve;

[0088] Alumina: 2.5%, calcite: 11%, dolomite: 7%, burned kaolin: 7%, wollastonite: 7%, zinc oxide: 2.5%;

[0089] Zirconium silicate: 7%, with a particle size distribution of D[4,3]8μm, ≤2μm accounting for 55%, ≤10μm accounting for 75%, and ≤20μm accounting for 95%;

[0090] Boron frit: 2%, with a melting temperature of 850°C, containing 10% B2O3, a Si / Al ratio of 3, 10% CaO+MgO, and no alkali metal elements.

[0091] In addition, the present invention provides a method for preparing high-quality ceramic glaze for sanitary ceramics, comprising the following preparation steps:

[0092] Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio;

[0093] Step 2: Mix the above-mentioned raw materials with an appropriate amount of water and wet-grind them using a ball mill for 5 hours until the average particle size of the slurry is less than 10 μm;

[0094] Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities;

[0095] Step 4: Add appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the slurry after adjustment needs to be controlled at 6.8;

[0096] The added dispersant is sodium polyacrylate, and the added ratio accounts for 0.3% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry. The added flow aid is sodium carboxymethyl cellulose, and the added ratio accounts for 0.7% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry;

[0097] Step 5: Apply the glaze evenly to the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled at 0.95 mm. The glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.3 MPa to make the glaze evenly distributed on the surface of the body. At the same time, during the glazing process, the glaze should be kept at room temperature of 24°C so that the glaze adheres better to the surface of the body after spraying.

[0098] Step 6: Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, use natural gas as the fuel gas, and set the firing cycle to 120 hours. Raise the temperature to 1203°C and maintain the temperature for 40 minutes for one sintering. During the sintering process, a multi-stage heating curve is adopted. The initial heating rate is controlled at 50°C / hour until the temperature reaches 800°C, and then the heating rate is increased to 100°C / hour until the maximum temperature reaches 1203°C.

[0099] Example A6

[0100] The ceramic glaze comprises, by weight percentage:

[0101] Potassium feldspar: 18%, sodium feldspar: 6%;

[0102] Quartz: 30%, with a particle size distribution of 2% on a 100-mesh sieve, 88% on a 250-mesh sieve, and 92% on a 350-mesh sieve;

[0103] Alumina: 2.5%, calcite: 11%, dolomite: 6%, burned kaolin: 7%, wollastonite: 7%, zinc oxide: 2.5%;

[0104] Zirconium silicate: 7%, with a particle size distribution of D[4,3]7μm, ≤2μm accounting for 55%, ≤10μm accounting for 79%, and ≤20μm accounting for 91%;

[0105] Boron frit: 3%, with a melting temperature of 850°C, containing 10% B2O3, a Si / Al ratio of 3.3, and 10% CaO+MgO, and containing no alkali metal elements.

[0106] The method for preparing high-quality ceramic glaze for sanitary ceramics comprises the following steps:

[0107] Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio;

[0108] Step 2: Mix the above-mentioned accurately weighed raw materials with an appropriate amount of water and wet-grind them using a ball mill for 6 hours until the average particle size of the slurry is less than 10 μm;

[0109] Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities;

[0110] Step 4: Add appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the slurry after adjustment needs to be controlled at 7;

[0111] The added dispersant is sodium polyacrylate, and the added ratio accounts for 0.5% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry. The added flow aid is sodium carboxymethyl cellulose, and the added ratio accounts for 0.9% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry;

[0112] Step 5: Apply the glaze evenly to the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled within 1.0 mm. The glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.5 MPa to make the glaze evenly distributed on the surface of the body. At the same time, during the glazing process, the glaze should be kept at room temperature of 25°C so that the glaze adheres better to the surface of the body after spraying.

[0113] Step 6: Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, use natural gas as the fuel gas, and set the firing cycle to 20 hours. Raise the temperature to 1197°C and maintain the temperature for 30 minutes for sintering. During the sintering process, a multi-stage heating curve is adopted. The initial heating rate is controlled at 50°C / hour until the temperature reaches 800°C, and then the heating rate is increased to 100°C / hour until the maximum temperature reaches 1973°C.

[0114] Comparative Example

[0115] Table 1 below shows the distribution of the original comparative example and Examples A1 to A6:

[0116]

[0117] The whiteness, color difference, and radioactivity performance of the ceramic glazes of Examples A1 to A6 and the original formulation were tested. The results are shown in Table 2.

[0118] Table 2

[0119]

[0120] Whiteness test: A CM-700D spectrophotometer was used to test the glaze color difference L, a, and b values. Color difference test: Using the original comparative example as the reference color plate, the color difference values ​​ΔE, ΔL, Δa, and Δb between Examples A1 to A6 were measured.

[0121] The above whiteness and color difference are measured at a standard glaze thickness of 0.65mm. Radioactivity test: The radioactivity of the fired glaze powder was tested using a BH1324F environmental gamma spectrometer in accordance with GB / T 11713-2015 "General Method for Gamma Spectroscopy Analysis of High-Purity Germanium".

[0122] Test results show that as the amount of zirconium silicate decreases, the whiteness value decreases significantly, and the color difference compared with the original color sample increases. As the amount of zirconium vanadium blue decreases, the whiteness value shows a certain upward trend, indicating that without affecting the color tone, the amount of zirconium vanadium blue is more suitable at 0.02%. The introduction of a certain amount of boron frit significantly improves the whiteness. Because boron frit forms multiple immiscible phases during the melting process, these microphase transformations cause multiple refractions and scatterings on the glaze surface, thereby enhancing the glaze's ability to refract and scatter light, resulting in a highly opalescent glaze.

[0123] Example B

[0124] The hardness index of this embodiment B is shown in Table 3:

[0125]

[0126] Example B is based on Example A6, but with the molar percentage of (SiO2 + Al2O3) in the overall chemical composition adjusted. The glaze hardness was tested using an HM-2TE Vickers hardness tester. The measured hardness value is the average of five random points on the glaze surface. Furthermore, the melt length test is used to evaluate the flow properties of the glaze during high-temperature firing, which directly affects the smoothness and fineness of the glaze surface. The test method involves taking 5 grams of dry glaze powder, forming a cylinder with a diameter of 14 mm and a height of 20 mm, and measuring the length of the cylinder flowing along a 45-degree slope.

[0127] In Example B, as the (SiO2 + Al2O3) content increases, the crystal structure inside the glaze layer forms a -Si-O-tetrahedron network. In this structure, the Al3+ of α-Al2O3 is interconnected through [AlO4] tetrahedrons, which strengthens the network structure of the glaze surface and thus improves the hardness of the glaze surface. At the same time, the specific particle size distribution of quartz used in the present invention can increase the proportion of free quartz crystals in the microstructure of the glaze, which is also an important factor in improving the hardness of the glaze surface.

[0128] However, simply increasing the hardness of the glaze may shorten the high-temperature fluidity (melting length) of the glaze, thereby affecting the gloss and fineness of the glaze. A melting length range of 80 to 85 mm is considered more appropriate, and the corresponding glaze hardness is 600 to 615 kgf / mm. 2 It can fully meet the production requirements.

[0129] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A high-quality ceramic glaze for sanitary ceramics, characterized in that: The ceramic glaze comprises, by weight percentage: Potassium feldspar: 15-23%, sodium feldspar: 4-10%, quartz: 28-34%, alumina: 1-4%, calcite: 8-14%, dolomite: 4-8%, burned kaolin: 4-8%, wollastonite: 6-8%, zinc oxide: 2-3%, zirconium silicate: 7-10%, boron frit: 2-3%; The boron frit has a melting temperature of 700-850°C, contains a B2O3 percentage of 7-10%, a Si / Al ratio of 3-3.3, a CaO+MgO percentage of 8-10%, and does not contain alkali metal elements. The boron frit is fired in a tunnel kiln at 1200°C, exhibits a phase-separated milky white color, and is introduced into the glaze formula to increase the whiteness of the glaze.

2. A high-quality ceramic glaze for sanitary ceramics according to claim 1, characterized in that: The particle size distribution of the zirconium silicate is: D[4,3]5-10μm, ≤2μm accounts for 55-65%, ≤10μm accounts for 75-85%, ≤20μm accounts for 85-95%, and the particle grading of the quartz is 1-3% residual on a 100-mesh sieve, 80-90% residual on a 250-mesh sieve, and 90-95% residual on a 350-mesh sieve.

3. The method for preparing a high-quality ceramic glaze for sanitary ceramics according to claim 1 or 2, characterized in that: The method comprises the following preparation steps: Step 1: accurately weigh potassium feldspar, sodium feldspar, quartz, alumina, calcite, dolomite, burned kaolin, wollastonite, zinc oxide, zirconium silicate and boron frit raw materials according to the ratio; Step 2: Mix the above-mentioned accurately weighed raw materials with an appropriate amount of water and wet-grind them using a ball mill for 4 to 6 hours until the average particle size of the slurry is less than 10 μm; Step 3: Sieve the ground slurry through a 200-mesh sieve to remove large particles and impurities, and then use a magnetic separation device to remove iron impurities; Step 4: Add appropriate amount of dispersant and flow aid to the slurry after screening to adjust the drying speed and fluidity of the slurry. The pH value of the slurry after adjustment needs to be controlled between 6.5 and 7.

5. Step 5: Apply the glaze evenly on the surface of the sanitary ceramic body. The total thickness of the glaze layer should be controlled within 0.85-1.0 mm. Step 6: Place the glazed body into a tunnel kiln, set the firing atmosphere to an oxidizing atmosphere, use natural gas as fuel, and set the firing cycle to 15 to 20 hours. Raise the temperature to 1197 to 1203°C and maintain the temperature for 30 to 40 minutes for a sintering cycle.

4. The method for preparing high-quality ceramic glaze for sanitary ceramics according to claim 3, characterized in that: The glazing equipment used in the glazing process is an automatic sprayer, and the spraying pressure is controlled at 0.3-0.5 MPa so that the glaze is evenly distributed on the surface of the green body. At the same time, during the glazing process, the glaze should be kept at room temperature of 20°C-25°C so that the glaze can better adhere to the surface of the green body after spraying.

5. The method for preparing high-quality ceramic glaze for sanitary ceramics according to claim 3, characterized in that: During the sintering process, a multi-stage heating curve is adopted. The initial heating rate is controlled at 100℃ / hour until the temperature reaches 800℃, then the heating rate is increased to 170℃ / hour until the temperature reaches 1100℃, and finally the heating rate is reduced to 50℃ / hour until the maximum temperature reaches 1197~1203℃.

6. The method for preparing high-quality ceramic glaze for sanitary ceramics according to claim 3, characterized in that: In the slurry preparation in step 4, the added dispersant is sodium polyacrylate, and the added proportion accounts for 0.1% to 0.5% of the total weight of the slurry. The dispersant is used to improve the dispersibility and stability of the slurry.

7. The method for preparing high-quality ceramic glaze for sanitary ceramics according to claim 3, characterized in that: In the slurry preparation in step 4, the flow aid used is sodium carboxymethyl cellulose, and the addition ratio accounts for 0.5% to 1.0% of the total weight of the slurry. The flow aid is used to improve the fluidity of the slurry.

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