Sapphire effect dry particle, ceramic tile with sapphire imitation effect and preparation method of ceramic tile

Abstract

The invention relates to the field of architectural ceramics, and discloses a sapphire effect dry particle, a ceramic tile with a sapphire imitation effect and a preparation method of the ceramic tile. The sapphire effect dry granules comprise blue dry granules and transparent dry granules, wherein the blue dry granules are prepared from the following raw materials: 1.5 to 3.5 parts of superfine tin dioxide, 15 to 19.5 parts of cobalt oxide, 4.5 to 7.5 parts of titanium oxide, 8 to 14 parts of zinc oxide, 32 to 43 parts of calcined aluminum oxide, 8 to 13 parts of quartz, 10 to 16 parts of potassium feldspar and 2.5 to 4.5 parts of boric acid; the transparent dry particles comprise the following raw materials in parts by weight: 8-15 parts of zinc oxide, 5-10 parts of aluminum oxide, 24-28 parts of quartz, 1-2.5 parts of nano silicon nitride and 7-11 parts of cryolite. By mixing the two dry granules, the frit dry granules which have a three-dimensional effect and an ice crack texture and imitate the texture of sapphire crystals can be prepared. The ceramic tile with the sapphire-like effect can be prepared by adopting the dry particles with the sapphire effect.

Description

Technical Field

[0001] The present invention relates to the field of architectural ceramics, and particularly to a sapphire-effect dry granule, a tile with an imitation sapphire effect, and a preparation method thereof. Background Art

[0002] Currently, imitation marble tiles in the industry usually use scanned patterns of marble stones for imitation, and usually can only imitate the surface texture trend, and the crystal texture of natural stones cannot be perfectly presented. Especially for precious stone types such as sapphire, it is very difficult to imitate ceramic products, and it is impossible to present a three-dimensional texture and ice crack effect like sapphire through glaze.

[0003] However, with the increase in consumer demand, the diversity of imitation marble tiles is facing challenges. Currently, blue glazed tiles are usually prepared by adding cobalt blue pigment or blue ink to the glaze, which can only control the depth of color to adjust the surface effect, and cannot truly restore the deep three-dimensional ice crack texture like sapphire. Therefore, there is an urgent need for a tile process with an imitation sapphire effect to solve the above problems. Summary of the Invention

[0004] The main object of the present invention is to provide a sapphire-effect dry granule that can form a bright, thick and deep imitation sapphire color effect.

[0005] To achieve the above object, the present invention provides a sapphire-effect dry granule. Based on the total weight of the sapphire-effect dry granule being 100%, the sapphire-effect dry granule includes: 85-90% of blue dry granules and 10-15% of transparent dry granules; The preparation raw materials of the blue dry granules include the following components in parts by weight: 1.5-3.5 parts of ultrafine tin dioxide, 15-19.5 parts of cobalt oxide, 4.5-7.5 parts of titanium oxide, 8-14 parts of zinc oxide, 32-43 parts of calcined alumina, 8-13 parts of quartz, 10-16 parts of potassium feldspar, and 2.5-4.5 parts of boric acid; The preparation raw materials of the transparent dry granules include the following components in parts by weight: 8-15 parts of zinc oxide, 5-10 parts of alumina, 24-28 parts of quartz, 1-2.5 parts of nano silicon nitride, and 7-11 parts of cryolite.

[0006] The present invention can prepare frit granules with a stereoscopic effect and a crackled texture similar to sapphire crystal texture by mixing blue dry granules and transparent dry granules. The blue dry granules utilize cobalt oxide and calcined alumina to form a cobalt blue color development system, and cooperate with the promoting effects of ultrafine tin dioxide, titanium oxide, and boric acid to present a sapphire crystal effect; the transparent dry granules use the compound of cryolite and nano silicon nitride to promote the formation of the blue dry granule melt on the one hand, and have a stable supporting effect during firing and melting, maintaining the material boundary of the blue dry granules, promoting the presentation of the visual texture of the blue dry granule particles, and restoring the unique real stone texture of sapphire.

[0007] Preferably, by mass percentage: The chemical composition of the blue dry granules includes: SiO2 10.3 - 16.2%, Al2O3 35.3 - 46.2%, SnO2 1.6 - 4.2%, K2O 1.9 - 3.6%, ZnO 8.6 - 13.7%, B2O3 1.5 - 2.7%, CoO 14.3 - 22.3%, TiO2 5.9 - 12.6% and L.O.I 2.4 - 5.8%; The chemical composition of the transparent dry granules includes: SiO2 45.3 - 56.2%, Al2O3 8.3 - 16.6%, ZnO 12.6 - 23.7%, Si3N4 1.6 - 4.2%, NaF 3.6 - 7.7% and L.O.I 4.4 - 6.8%.

[0008] Preferably, the blue dry granules are obtained by melting the raw materials at 1250 - 1350 °C and then quenching and grinding. The particle size distribution is: 45 - 60% of 10 - 20 mesh, 25 - 30% of 20 - 40 mesh, and 12 - 30% of 40 - 80 mesh; the transparent dry granules are obtained by melting the raw materials at 1300 - 1450 °C and then quenching and grinding, and the particle size is 400 - 600 mesh.

[0009] In a second aspect, the present invention also provides a ceramic tile with an imitation sapphire effect, which sequentially includes a body layer, a base glaze layer, a pattern layer, a sapphire dry granule layer, and a dry granule protective glaze layer; the sapphire dry granule layer is prepared from the sapphire effect dry granules as described above.

[0010] Preferably, the dry granule protective glaze layer is prepared from a dry granule protective glaze slurry; based on the total weight of the dry granule protective glaze slurry being 100%, the dry granule protective glaze slurry includes 50 - 55% of protective dry granules and 45 - 50% of a dry granule suspending agent; The preparation raw materials of the protective dry granules include the following components in parts by weight: 23 - 27 parts of potassium feldspar, 3 - 5 parts of calcined alumina, 10 - 15 parts of kaolin, 4 - 8 parts of zinc oxide, and 8 - 13 parts of quartz; The chemical composition of the protective dry granules, by mass percentage, includes: SiO2 59.6 - 64.3%, Al2O3 14.9 - 18.6%, K2O 3.5 - 5.9%, ZnO 6.5 - 11.2% and L.O.I 4.1 - 7.5%.

[0011] The protective dry granules are obtained by melting the raw materials at 1300 - 1450 °C, followed by water quenching and grinding.

[0012] The glaze slurry for protecting dry granules is prepared with high-viscosity protective dry granules and covers the surface of the sapphire-effect dry granules, which can further maintain the color texture of the sapphire-effect dry granules and form a deep visual effect of gemstone inlay.

[0013] Preferably, the raw materials for preparing the bottom glaze layer include the following components by weight: 5 - 10 parts of zinc oxide, 1 - 3 parts of barium carbonate, 15 - 20 parts of potassium feldspar, 10 - 15 parts of sodium feldspar, 1.5 - 3.5 parts of calcined talc, 1 - 3.5 parts of calcite, 13 - 19 parts of quartz, 5 - 8 parts of dolomite, 7 - 11 parts of calcined kaolin, 8.5 - 12 parts of washed kaolin, and 6 - 12 parts of alumina; The chemical composition of the bottom glaze layer, by mass percentage, includes: SiO2 48.1 - 56.3%, Al2O3 16.3 - 19.1%, ZnO 5.9 - 10.7%, CaO 2.3 - 3.9%, MgO 1.9 - 4.8%, K2O 3.5 - 4.8%, Na2O 3.3 - 4.7%, BaO 0.6 - 1.6% and L.O.I 2.3 - 5.9%.

[0014] The formula of the bottom glaze promotes the stable color development of the sapphire-effect layer.

[0015] Preferably, the raw materials for preparing the green body layer include the following components by weight: 9.5 - 11.5 parts of raw ore mud, 1.3 - 3.5 parts of bentonite, 6.6 - 9.5 parts of kaolin, 8.5 - 11.5 parts of washed mud, 33.5 - 38.3 parts of stone powder, 16.2 - 22.3 parts of high-aluminum potassium sand, and 1 - 3 parts of talc; The chemical composition of the green body layer, by mass percentage, includes: SiO2 60.3 - 67.3%, Al2O3 19.7 - 23.2%, CaO 1.1 - 2.5%, MgO 0.2 - 0.8%, K2O 2.3 - 4.5%, Na2O 0.6 - 1.3%, Fe2O3 0.2 - 0.6% and L.O.I 3.3 - 7.6%.

[0016] Thirdly, the present invention also provides a method for preparing the above-mentioned ceramic tile with an imitation sapphire effect, including the following steps: S1. Prepare the green body to obtain the green body layer; S2. Apply the base glaze on the surface of the green body layer to obtain a base glaze layer; S3. Inkjet print a color pattern on the surface of the base glaze layer to obtain a pattern layer; S4. After inkjet printing the positioning glue on the surface of the pattern layer, apply the sapphire effect dry particles to obtain a sapphire dry particle layer; S5. Apply the dry particle protective glaze slurry on the surface of the sapphire dry particle layer to obtain a dry particle protective glaze layer; S6. Feed it into a kiln for firing to obtain the tile with the imitation sapphire effect.

[0017] Preferably, in step S4, the application amount of the positioning glue is 130 - 200 g / m 2 ; the proportion of the printed pattern of the positioning glue is 60 - 90%. By controlling the application amount of the positioning glue, the quantity difference of the sapphire effect dry particles is controlled, so as to achieve the differential effect of different shades of blue crystals.

[0018] Preferably, in step S4, the application amount of the sapphire effect dry particles is 200 - 360 g / m 2 .

[0019] Preferably, in step S5, the application amount of the dry particle protective glaze slurry is 450 - 600 g / m 2 , and the specific gravity is 1.50 - 1.55 g / mL.

[0020] Preferably, in step S6, the firing process includes: Preheating stage: The heating rate is 25 - 35 °C / min, and the temperature range is from room temperature to 350 °C; Oxidation and decomposition stage: The heating rate is 30 - 40 °C / min, and the temperature range is 350 - 950 °C; High - temperature stage: The heating rate is 20 - 25 °C / min, and the temperature range is 950 °C to the maximum firing temperature; High - fire holding stage: The time is 2 - 5 min; And cooling stage: The cooling rate in the temperature range from the maximum firing temperature to 600 °C is 25 - 35 °C / min; the cooling rate in the temperature range from 600 to 500 °C is 15 - 20 °C / min; the cooling rate in the temperature range from 500 °C to room temperature is 35 - 40 °C / min; The maximum firing temperature is 1150 - 1210 °C.

[0021] The present invention selects a fast - firing process that is more suitable for the sapphire effect dry particles and the dry particle protective glaze layer, and adopts a shorter high - temperature holding stage to further cooperate with the firing effect of the two kinds of mixed dry particles in the sapphire effect dry particles, so as to achieve a more perfect imitation sapphire texture. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a physical diagram of Embodiment 3; Figure 2 It is a physical diagram of Comparative Example 4; Figure 3 It is a physical diagram of Comparative Example 5.

[0024] The realization of the purpose of the present application, the functional characteristics and advantages will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed Embodiments

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. At the same time, for the raw materials not detailedly described below, they are all commercially available products; for the process steps or preparation methods not detailedly mentioned, they are all process steps or preparation methods known to those skilled in the art.

[0026] The present invention provides a sapphire-effect dry granule. Calculated based on the total weight of the sapphire-effect dry granule being 100%, the sapphire-effect dry granule includes 85-90% of blue dry granules and 10-15% of transparent dry granules; Among them, the preparation raw materials of the blue dry granules include the following components in parts by weight: 1.5-3.5 parts of ultrafine tin dioxide, 15-19.5 parts of cobalt oxide, 4.5-7.5 parts of titanium oxide, 8-14 parts of zinc oxide, 32-43 parts of calcined alumina, 8-13 parts of quartz, 10-16 parts of potassium feldspar, and 2.5-4.5 parts of boric acid; the preparation raw materials of the transparent dry granules include the following components in parts by weight: 8-15 parts of zinc oxide, 5-10 parts of alumina, 24-28 parts of quartz, 1-2.5 parts of nano silicon nitride, and 7-11 parts of cryolite.

[0027] The blue dry granules of the present invention are mainly based on the cobalt blue color development system formed by cobalt oxide and calcined alumina, which promotes the overall formation of a dark blue color in the glaze melt. After rapid cooling and crushing, a sapphire crystal effect is presented. The ultra-fine tin dioxide in the formula system accounts for a relatively small proportion. Utilizing its ability to retain fine grains even at a high temperature of 1280 °C, a delicate and slight opacifying effect is formed, presenting a thick and profound visual effect of the melt. It should be particularly noted that the ultra-fine tin dioxide described in the present invention specifically refers to particles with a particle size of 2000 - 2800 mesh. At this particle size, the uniformity of tin dioxide is better, and it presents a uniform semi-transparent blue color after firing, with a better decorative effect. The addition amount of titanium oxide is adjusted so that it transforms into rutile-type crystals during high-temperature firing. The appearance of this crystal form is like cold and icy, columnar or needle-shaped, combined with the molten liquid-phase quartz body, presenting a dense massive crystal effect. It should be noted that the excessive addition of titanium oxide powder may cause the rutile color to form on the glaze surface and affect the cobalt blue background color. Therefore, how to utilize titanium oxide to present the crystal texture without affecting the color development of the sapphire blue is a major problem to be solved in the present invention. The added boric acid in the formula acts as a mineralizer to promote the crystallization effect; zinc oxide promotes color development and makes the cobalt blue color more vivid. Quartz powder and potassium feldspar provide the glass phase and maintain the visual effect of the ice-like material after the melt is rapidly cooled. The transparent dry granules adopt a zinc-aluminum-silicon structure and will not affect the color of the blue dry granules. At the same time, cryolite in the formula forms a complex ionic structure in the molten state and can interact with alumina. The aluminum ions and fluoride ions in the cryolite structure interact with the aluminum ions and cations in alumina to form relatively stable complex ions, thereby changing the crystal structure of alumina and making it melt at a lower temperature, promoting the formation of the blue dry granule melt. At the same time, combined with the three-dimensional lattice structure of nano-silicon nitride in the formula, it has high thermal stability at high temperatures. The nano-scale powder forms a uniform and stable supporting effect in the blue dry granule melt, ensuring that the blue dry granules and the transparent dry granules can still maintain their respective material boundaries in the fired and molten state, and thus forming a unique imitation stone texture.

[0028] Further, by mass percentage: The chemical composition of the blue dry granules includes: SiO2 10.3 - 16.2%, Al2O3 35.3 - 46.2%, SnO2 1.6 - 4.2%, K2O 1.9 - 3.6%, ZnO 8.6 - 13.7%, B2O3 1.5 - 2.7%, CoO 14.3 - 22.3%, TiO2 5.9 - 12.6% and L.O.I 2.4 - 5.8%; the chemical composition of the transparent dry granules includes: SiO2 45.3 - 56.2%, Al2O3 8.3 - 16.6%, ZnO 12.6 - 23.7%, Si3N4 1.6 - 4.2%, NaF 3.6 - 7.7% and L.O.I 4.4 - 6.8%. It should be noted that both the blue dry granules and the transparent dry granules adopt the well-known frit preparation process. In the present invention, the preparation process of the blue dry granules includes: mixing the raw materials of the blue dry granules, melting them in a high-temperature furnace at 1250 - 1350 °C, rapidly cooling the melt and then crushing and grinding it, and screening to obtain the required mesh number. The particle size distribution of the blue dry granules is: 45 - 60% for 10 - 20 mesh, 25 - 30% for 20 - 40 mesh, and 12 - 30% for 40 - 80 mesh. The preparation process of the transparent dry granules includes: mixing the raw materials of the transparent dry granules, melting them in a high-temperature furnace at 1300 - 1450 °C, rapidly cooling the melt and then crushing and grinding it, and passing through a standard sieve between 400 - 600 mesh to obtain the transparent dry granules. Strictly controlling the particle sizes of the blue dry granules and the transparent dry granules is more conducive to the formation of a well-defined crystal texture through the mixing effect of the two frits, presenting the jade texture of real stone.

[0029] The present invention also provides a ceramic tile with an imitation sapphire effect, which sequentially includes a body layer, an underglaze layer, a pattern layer, a sapphire dry granule layer, and a dry granule protective glaze layer; the sapphire dry granule layer is prepared from the sapphire effect dry granules as described above.

[0030] Furthermore, the dry granule protective glaze layer is prepared from the dry granule protective glaze slurry; based on the total weight of the dry granule protective glaze slurry being 100%, the dry granule protective glaze slurry includes 50 - 55% of protective dry granules and 45 - 50% of dry granule suspending agent; Among them, the preparation raw materials of the protective dry granules include the following components by weight: 23 - 27 parts of potassium feldspar, 3 - 5 parts of calcined alumina, 10 - 15 parts of kaolin, 4 - 8 parts of zinc oxide, and 8 - 13 parts of quartz; the chemical composition of the protective dry granules by mass percentage includes: SiO2 59.6 - 64.3%, Al2O3 14.9 - 18.6%, K2O 3.5 - 5.9%, ZnO 6.5 - 11.2% and L.O.I 4.1 - 7.5%.

[0031] The main component of the dry particle protective glaze slurry used in the present invention is a high-viscosity protective dry particle, with a viscosity of 7200-8100 Pa·S under high-temperature firing. At this viscosity, the molten sapphire-effect dry particles can maintain the particle morphology of sapphire, and finally present a visual effect like a gemstone ore. In addition, the formula of the protective dry particle adopts a zinc-silicon system, which does not affect the color presentation of the sapphire-effect dry particles. The protective dry particle can also adopt the well-known frit preparation process. Mix the raw materials of the protective dry particle, and melt them in a high-temperature furnace at 1300-1450°C. Quench the melt and then crush and grind it. The fineness of the protective dry particle is controlled to have a sieve residue of 0.1-0.4% on a 325-mesh sieve. The dry particle suspending agent in the dry particle protective glaze slurry is a well-known commercially available suspending agent, such as the 9022A dry particle suspending agent provided by Jiangxi Qiantao New Materials Co., Ltd. The dry particle protective glaze slurry is applied on the sapphire dry particle layer. On the one hand, it plays a protective role. On the other hand, the dry particle protective glaze slurry covering the surface of the sapphire-effect dry particles does not affect the color effect of the sapphire-effect dry particles, and at the same time, after firing, it presents a wrapped feeling, simulating the visual effect of a gemstone inlaid inside, with a transparent texture.

[0032] Further, the preparation raw materials of the bottom glaze layer include the following components in parts by weight: 5-10 parts of zinc oxide, 1-3 parts of barium carbonate, 15-20 parts of potassium feldspar, 10-15 parts of sodium feldspar, 1.5-3.5 parts of calcined talc, 1-3.5 parts of calcite, 13-19 parts of quartz, 5-8 parts of dolomite, 7-11 parts of calcined kaolin, 8.5-12 parts of washed kaolin, and 6-12 parts of alumina; the chemical composition of the bottom glaze layer, in mass percentage, includes: SiO2 48.1-56.3%, Al2O3 16.3-19.1%, ZnO 5.9-10.7%, CaO 2.3-3.9%, MgO 1.9-4.8%, K2O 3.5-4.8%, Na2O 3.3-4.7%, BaO 0.6-1.6%, and L.O.I 2.3-5.9%.

[0033] On the one hand, the bottom glaze forms a concealer effect on the green body. On the other hand, the main flux in the formula is zinc oxide, which plays a role in promoting the color development of the sapphire-effect dry particles, ensuring that the bright blue color presented by the sapphire-effect dry particles has stable color development.

[0034] Further, the raw materials for preparing the green body layer include the following components by weight: 9.5 - 11.5 parts of raw ore mud, 1.3 - 3.5 parts of bentonite, 6.6 - 9.5 parts of kaolin, 8.5 - 11.5 parts of washed mud, 33.5 - 38.3 parts of stone powder, 16.2 - 22.3 parts of high-aluminum potassium sand, and 1 - 3 parts of talc; the chemical composition of the green body layer, by mass percentage, includes: 60.3 - 67.3% of SiO2, 19.7 - 23.2% of Al2O3, 1.1 - 2.5% of CaO, 0.2 - 0.8% of MgO, 2.3 - 4.5% of K2O, 0.6 - 1.3% of Na2O, 0.2 - 0.6% of Fe2O3, and 3.3 - 7.6% of L.O.I.

[0035] The present invention also provides a method for preparing the above-mentioned ceramic tile with an imitation sapphire effect, which includes the following steps: S1. Prepare a green body to obtain a green body layer; the pressing thickness of the green body can be 10.5 - 13 mm.

[0036] S2. Apply a base glaze on the surface of the green body layer to obtain a base glaze layer; S3. Inkjet print a color pattern on the surface of the base glaze layer to obtain a pattern layer; S4. After inkjet printing a positioning glue on the surface of the pattern layer, apply sapphire effect dry particles to obtain a sapphire dry particle layer; S5. Apply a dry particle protective glaze slurry on the surface of the sapphire dry particle layer to obtain a dry particle protective glaze layer; S6. Send it into a kiln for firing to obtain the above-mentioned ceramic tile with an imitation sapphire effect.

[0037] In step S4, the positioning glue is used to attach the sapphire effect dry particles. The positioning glue is purchased from Foshan Yidajia Precision Ceramics Technology Co., Ltd., and it is CIK-AD1109 glue. It is sprayed on the surface of the green body after applying the base glaze by an inkjet printer. The preferably sprayed glue amount is 130 - 200 g / m 2 ; the optimal proportion of the printed pattern of the positioning glue is 60 - 90%. By adjusting the amount of the positioning glue, the number of sapphire effect dry particles at different positions is adjusted, so as to achieve the effect of adjusting the depth of the blue crystals after firing.

[0038] Preferably, in step S4, the applied amount of the sapphire effect dry particles is 200 - 360 g / m 2 In step S5, the application method of the dry particle protective glaze slurry is a conventional spray cabinet. By adjusting the swing frequency of the equipment, the preferably applied amount of the dry particle protective glaze slurry is 450 - 600 g / m 2 , and the specific gravity is 1.50 - 1.55 g / mL.

[0039] Further, in step S6, the firing process includes: Preheating stage: heating rate is 25~35℃ / min, temperature range is room temperature~350℃; Oxidation decomposition stage: heating rate is 30~40℃ / min, temperature range is 350~950℃; High temperature stage: the heating rate is 20~25℃ / min, and the temperature range is 950℃~the highest firing temperature; High fire insulation stage: time 2~5min; And cooling stage: the cooling rate of the temperature section from the highest firing temperature to 600℃ is 25~35℃ / min; the cooling rate of the temperature section from 600℃ to 500℃ is 15~20℃ / min; the cooling rate of the temperature section from 500℃ to room temperature is 35~40℃ / min; The maximum firing temperature is 1150~1210℃.

[0040] It should be noted that the above preparation method also includes the steps of polishing, waxing and edge grinding the fired tiles.

[0041] Since the glaze of the present invention mainly adopts frit glaze with small firing loss, a special fast firing process is adopted for the glaze system of the present invention to shorten the high temperature insulation time to further coordinate the firing effect of the blue dry particles and the transparent dry particles in the sapphire effect dry particles after mixing the two frits.

[0042] The following examples are further listed to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all belong to the scope of protection of the present invention. The specific process parameters of the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description of this article, and are not intended to be limited to the specific values ​​of the examples below. If the specific conditions are not specified in the examples, proceed according to conventional conditions or the conditions recommended by the manufacturer.

[0043] Example 1 A ceramic tile with imitation sapphire effect, the preparation method comprises the following steps: S1. Prepare ceramic raw materials into a green body to obtain a green body layer; wherein the raw materials for preparing the green body layer include the following components in parts by weight: 10 parts of original ore mud, 3 parts of bentonite, 7.5 parts of kaolin, 10 parts of washed mud, 34 parts of stone powder, 18 parts of high-aluminum potassium sand and 2 parts of talc; the chemical composition of the green body layer includes SiO2 65.3%, Al2O3 21.7%, CaO 1.4%, MgO 0.3%, K2O 3.7%, Na2O 0.9%, Fe2O3 0.4% and LOI 6.3% in mass percentage.

[0044] S2. Apply the base glaze on the surface of the green body layer to obtain a base glaze layer. Among them, the base glaze (in this embodiment, a conventional base glaze on the market is used) includes the following components by mass fraction: 55 parts of albite, 5 parts of quartz, 16 parts of calcined kaolin, 7 parts of washed kaolin, 14 parts of alumina, and 10 parts of zirconium silicate. The chemical composition of the base glaze layer by mass percentage includes 52.4% of SiO2, 23.5% of Al2O3, 6.4% of ZrO2, 12.3% of Na2O, and 5.4% of L.O.I.

[0045] S3. Inkjet print a color pattern on the surface of the base glaze layer to obtain a pattern layer. S4. Inkjet print positioning glue on the surface of the pattern layer, and the amount of glue is 160 g / m 2 , and the proportion of the printed pattern is 75%; apply sapphire effect dry particles, and the application amount is 230 g / m 2 , to obtain a sapphire dry particle layer. Among them, the sapphire effect dry particles include 85% blue dry particles and 15% transparent dry particles. By weight, the blue dry particles include the following components: 1.5 parts of ultrafine tin dioxide, 15 parts of cobalt oxide, 5.5 parts of titanium oxide, 9 parts of zinc oxide, 40 parts of calcined alumina, 9 parts of quartz, 11 parts of potassium feldspar, and 2.5 parts of boric acid. The chemical composition of the blue dry particles includes: 14.3% of SiO2, 43.7% of Al2O3, 2.1% of SnO2, 2.2% of K2O, 9.2% of ZnO, 2.3% of B2O3, 14.7% of CoO, 6.0% of TiO2, and 5.5% of L.O.I.

[0046] After the raw materials of the blue dry particles are mixed evenly, they are melted at 1300 °C, and then quenched and ground with water to prepare blue dry particles with a particle size distribution of 50% with a particle size of 10 - 20 mesh and above, 30% with a particle size of 20 - 40 mesh, and 20% with a particle size of 40 - 80 mesh.

[0047] By weight, the transparent dry particles include the following components: 8 parts of zinc oxide, 6 parts of alumina, 28 parts of quartz, 2 parts of nano silicon nitride, and 7 parts of cryolite.

[0048] After the raw materials of the transparent dry particles are mixed evenly, they are melted at 1350 °C, and then quenched and ground with water, and then sieved through a 400 - mesh sieve to obtain the transparent dry particles. The chemical composition of the transparent dry particles includes: 55.3% of SiO2, 14.2% of Al2O3, 15.8% of ZnO, 3.9% of Si3N4, 6.2% of NaF, and 4.6% of L.O.I.

[0049] S5. Apply dry particle protective glaze slurry on the surface of the sapphire dry particle layer, and the application amount is 460 g / m 2, with a specific gravity of 1.50 g / mL, to obtain a dry particle protective glaze layer; wherein, the dry particle protective glaze slurry comprises 50% of protective dry particles and 50% of 9022A dry particle suspending agent; By weight, the protective dry particles comprise the following components: 23 parts of potassium feldspar, 5 parts of calcined alumina, 10 parts of kaolin, 7 parts of zinc oxide, and 13 parts of quartz. The chemical composition of the protective dry particles, by mass percentage, comprises: 62.2% of SiO2, 17.5% of Al2O3, 3.8% of K2O, 9.9% of ZnO, and 6.6% of L.O.I.

[0050] After the raw materials of the protective dry particles are uniformly mixed, they are melted at 1300 °C, then quenched with water and ground, and passed through a 325-mesh sieve with a residue of 0.1 - 0.4% to obtain the protective dry particles.

[0051] S6. Feed it into a kiln for firing, and the firing process is as follows: heating rate of 30 °C / min from room temperature to 350 °C; heating rate of 35 °C / min from 350 °C to 950 °C; heating rate of 25 °C / min from 950 to 1200 °C; holding for 2 min; cooling rate of 30 °C / min from 1200 °C to 600 °C; cooling rate of 15 °C / min from 600 °C to 500 °C; cooling rate of 35 °C / min from 500 °C to room temperature. Then a ceramic tile with an imitation sapphire effect is obtained.

[0052] Example 2 A ceramic tile with an imitation sapphire effect, and the preparation method comprises the following steps: S1. Prepare the ceramic raw materials into a green body to obtain a green body layer; wherein, the raw materials for preparing the green body layer, by weight, comprise the following components: 10 parts of raw ore mud, 3 parts of bentonite, 7.5 parts of kaolin, 10 parts of washed mud, 34 parts of stone powder, 18 parts of high-aluminum potassium sand, and 2 parts of talc; the chemical composition of the green body layer, by mass percentage, comprises 65.3% of SiO2, 21.7% of Al2O3, 1.4% of CaO, 0.3% of MgO, 3.7% of K2O, 0.9% of Na2O, 0.4% of Fe2O3, and 6.3% of L.O.I.

[0053] S2. Apply the base glaze on the surface of the green body layer to obtain the base glaze layer. Among them, by weight, the base glaze includes the following components: 9 parts of zinc oxide, 3 parts of barium carbonate, 19 parts of potassium feldspar, 15 parts of sodium feldspar, 3.5 parts of calcined talc, 2 parts of calcite, 13 parts of quartz, 5 parts of dolomite, 7 parts of calcined kaolin, 8.5 parts of washed kaolin, and 7 parts of alumina. The chemical composition of the base glaze layer, by mass percentage, includes: 53.3% of SiO₂, 18.2% of Al₂O₃, 9.5% of ZnO, 2.9% of CaO, 2.1% of MgO, 3.9% of K₂O, 3.5% of Na₂O, 0.9% of BaO, and 5.7% of L.O.I.

[0054] S3. Inkjet print a color pattern on the surface of the base glaze layer to obtain the pattern layer. S4. Inkjet print positioning glue on the surface of the pattern layer, and the amount of glue is 130 g / m 2 , and the proportion of the printed pattern is 60%; apply sapphire effect dry particles, and the application amount is 200 g / m 2 , to obtain the sapphire dry particle layer. Among them, the sapphire effect dry particles include 90% blue dry particles and 10% transparent dry particles; By weight, the blue dry particles include the following components: 3 parts of ultrafine tin dioxide, 19 parts of cobalt oxide, 7.5 parts of titanium oxide, 14 parts of zinc oxide, 33 parts of calcined alumina, 13 parts of quartz, 15 parts of potassium feldspar, and 4.5 parts of boric acid. The chemical composition of the blue dry particles includes: 12.3% of SiO₂, 38.6% of Al₂O₃, 2.7% of SnO₂, 2.9% of K₂O, 12.8% of ZnO, 2.6% of B₂O₃, 17.2% of CoO, 6.3% of TiO₂, and 4.6% of L.O.I.

[0055] After the raw materials of the blue dry particles are mixed evenly, they are melted at 1340 °C, and then quenched and ground to prepare the blue dry particles with a particle size distribution of 60% for 10 - 20 mesh, 25% for 20 - 40 mesh, and 15% for 40 - 80 mesh.

[0056] By weight, the transparent dry particles include the following components: 13 parts of zinc oxide, 8 parts of alumina, 26 parts of quartz, 1 part of nano silicon nitride, and 9 parts of cryolite.

[0057] After the raw materials of the transparent dry particles are mixed evenly, they are melted at 1400 °C, and then quenched and ground, and then sieved through a 500 - mesh sieve to obtain the transparent dry particles. The chemical composition of the transparent dry particles includes: 46.3% of SiO₂, 15.1% of Al₂O₃, 22.8% of ZnO, 2.2% of Si₃N₄, 6.9% of NaF, and 6.7% of L.O.I.

[0058] S5. Apply transparent protective glaze slurry on the surface of the sapphire dry particle layer, and the application amount is 590 g / m2 , with a specific gravity of 1.55 g / mL, to obtain a protective glaze layer; among them, by weight, the transparent protective glaze (in this embodiment, a commercially available conventional transparent protective glaze is used) includes the following components: 10 parts of albite, 15 parts of orthoclase, 6 parts of calcined talc, 8 parts of wollastonite, 5 parts of strontium carbonate, 15 parts of quartz, 15 parts of dolomite, 17 parts of calcined kaolin, and 10 parts of washed kaolin. The chemical composition of the transparent protective glaze, by mass percentage, includes: SiO₂ 57.8%, Al₂O₃ 18.9%, K₂O 3.1%, Na₂O 2.7%, SrO 4.6%, CaO 4.1%, MgO 3.7%, and L.O.I 5.1%.

[0059] S6. Feed it into a kiln for firing, and the firing process is as follows: heating rate of 33 °C / min from room temperature to 350 °C; heating rate of 38 °C / min from 350 °C to 950 °C; heating rate of 21 °C / min from 950 to 1200 °C; holding for 4 min; cooling rate of 35 °C / min from 1200 °C to 600 °C; cooling rate of 15 °C / min from 600 °C to 500 °C; cooling rate of 38 °C / min from 500 °C to room temperature. Then the ceramic tile with the effect of imitating sapphire is obtained.

[0060] Example 3 A ceramic tile with the effect of imitating sapphire, and the preparation method includes the following steps: S1. Prepare a green body from ceramic raw materials to obtain a green body layer; among them, the raw materials for preparing the green body layer, by weight, include the following components: 10 parts of raw ore mud, 3 parts of bentonite, 7.5 parts of kaolin, 10 parts of washed mud, 34 parts of stone powder, 18 parts of high-aluminum potassium sand, and 2 parts of talc; the chemical composition of the green body layer, by mass percentage, includes SiO₂ 65.3%, Al₂O₃ 21.7%, CaO 1.4%, MgO 0.3%, K₂O 3.7%, Na₂O 0.9%, Fe₂O₃ 0.4%, and L.O.I 6.3%.

[0061] S2. Apply a base glaze on the surface of the green body layer to obtain a base glaze layer; among them, by weight, the base glaze includes the following components: 7 parts of zinc oxide, 2 parts of barium carbonate, 17 parts of orthoclase, 13 parts of albite, 2.5 parts of calcined talc, 2.5 parts of calcite, 16 parts of quartz, 7 parts of dolomite, 9 parts of calcined kaolin, 10 parts of washed kaolin, and 9 parts of alumina. The chemical composition of the base glaze layer, by mass percentage, includes: SiO₂ 54.6%, Al₂O₃ 18.1%, ZnO 8.6%, CaO 2.9%, MgO 2.3%, K₂O 3.7%, Na₂O 3.4%, BaO 0.9%, and L.O.I 5.5%.

[0062] S3. Inkjet print a color pattern on the surface of the base glaze layer to obtain a pattern layer; S4. Inkjet print positioning glue on the surface of the pattern layer, with the glue amount being 180 g / m 2 , and the proportion of the printed pattern being 85%; Apply sapphire effect dry particles, with the application amount being 300 g / m 2 , to obtain a sapphire dry particle layer; Among them, the sapphire effect dry particles include 88% blue dry particles and 12% transparent dry particles; By weight, the blue dry particles include the following components: 2.5 parts of ultrafine tin dioxide, 18 parts of cobalt oxide, 6.5 parts of titanium oxide, 11 parts of zinc oxide, 38 parts of calcined alumina, 10 parts of quartz, 13 parts of potassium feldspar, and 3.5 parts of boric acid. The chemical composition of the blue dry particles includes: SiO2 14.2%, Al2O3 39.8%, SnO2 2.7%, K2O 2.3%, ZnO 10.5%, B2O3 1.7%, CoO 17.4%, TiO2 6.9%, and L.O.I 4.5%.

[0063] After the raw materials of the blue dry particles are mixed evenly, they are melted at 1310 °C, and then quenched and ground with water to prepare the blue dry particles with a particle size distribution of 52% for 10 - 20 mesh, 28% for 20 - 40 mesh, and 20% for 40 - 80 mesh.

[0064] By weight, the transparent dry particles include the following components: 12 parts of zinc oxide, 7 parts of alumina, 26 parts of quartz, 1.5 parts of nano silicon nitride, and 9 parts of cryolite.

[0065] After the raw materials of the transparent dry particles are mixed evenly, they are melted at 1380 °C, and then quenched and ground with water, and then sieved through a 600 - mesh sieve to obtain the transparent dry particles. The chemical composition of the transparent dry particles includes: SiO2 51.5%, Al2O3 13.5%, ZnO 21.8%, Si3N4 2.6%, NaF 4.5%, and L.O.I 6.1%.

[0066] S5. Apply dry particle protective glaze slurry on the surface of the sapphire dry particle layer, with the application amount being 530 g / m 2 , and the specific gravity being 1.53 g / mL, to obtain a dry particle protective glaze layer; Among them, the dry particle protective glaze slurry includes 53% protective dry particles and 47% 9022A dry particle suspending agent; By weight, the protective dry particles include the following components: 25 parts of potassium feldspar, 4 parts of calcined alumina, 12 parts of kaolin, 6 parts of zinc oxide, and 11 parts of quartz. The chemical composition of the protective dry particles by mass percentage includes: SiO2 61.3%, Al2O3 16.6%, K2O 5.6%, ZnO 10.5%, and L.O.I 6.0%.

[0067] After the raw materials for protecting the dry granules are uniformly mixed, they are melted at 1390 °C, then quenched with water and ground, and passed through a 325-mesh sieve with a residue of 0.1-0.4% to obtain the protected dry granules.

[0068] S6. Feed it into a kiln for firing. The firing process is as follows: The heating rate is 33 °C / min from room temperature to 350 °C; the heating rate is 38 °C / min from 350 °C to 950 °C; the heating rate is 23 °C / min from 950 to 1200 °C; keep warm for 3 min; the cooling rate is 33 °C / min from 1200 °C to 600 °C; the cooling rate is 19 °C / min from 600 °C to 500 °C; the cooling rate is 38 °C / min from 500 °C to room temperature. Then the ceramic tiles with sapphire-like effects are obtained.

[0069] Comparative Examples 1-5 The preparation methods and parameters of the ceramic tiles in Comparative Examples 1-5 are the same as those in Example 3, except that the raw materials for preparing the dry granules with sapphire effects are adjusted as shown in Tables 1-3.

[0070] Table 1 Raw materials for preparing blue dry granules in Comparative Examples 1-5 (parts by weight) Table 2 Raw materials for preparing transparent dry granules in Comparative Examples 1-5 (parts by weight) Table 3 Raw materials for preparing dry granules with sapphire effects in Comparative Examples 1-5 (%) Comparative Example 6 This comparative example uses the same preparation process and parameters as in Example 3, except that the firing process is adjusted as shown in Tables 4 and 5: Table 4 Heating stage Table 5 Cooling stage Observe the pattern texture clarity and glaze effect of the ceramic tiles prepared in Examples 1-3 and Comparative Examples 1-6. The specific test results are shown in Table 6.

[0071] Table 6 Note: The glaze decoration effect is directly observed by the naked eye. There are 30 testers. The main comparison is the similarity between the color and texture of the ceramic tiles in this scheme and natural sapphire stone. If ≥27 people think that the surface effects of the two are close, it is marked as excellent; if 24-26 people think that the surface effects of the two are close, it is marked as good; if 20-23 people think that the surface effects of the two are close, it is marked as average; the rest are marked as poor.

[0072] As can be seen from Table 6, the tiles prepared by this solution have bright colors and clear pattern textures. As shown in Figure 1 (Example 3), they have a high similarity to sapphire stone. In Comparative Examples 1-4, the formulation components of the sapphire-effect dry granules were adjusted to varying degrees, resulting in an imbalance in the compounding effect and affecting the crystal texture after firing, thus making the pattern texture less clear, the boundaries less distinct, and the decorative effect mediocre. As shown in Figure 2 (Comparative Example 4). In Comparative Example 5, only blue dry granules were used, and the fired glaze surface was entirely blue, with blurred textures and low clarity, resulting in a poor decorative effect. As shown in Figure 3 . In Comparative Example 6, the firing process was adjusted, with both the heating and cooling rates being relatively fast and the holding time being too long, which was not conducive to crystal formation, resulting in unclear pattern interfaces and a mediocre decorative effect.

[0073] Example 4 In this example, all conditions were the same as in Example 1, except that the base glaze included the following components: 7 parts of zinc oxide, 3 parts of barium carbonate, 16 parts of potassium feldspar, 14 parts of sodium feldspar, 3 parts of calcined talc, 1.5 parts of calcite, 14 parts of quartz, 6 parts of dolomite, 8 parts of calcined kaolin, 9.5 parts of washed kaolin, and 10 parts of alumina. The chemical composition of the base glaze layer, by mass percentage, included: SiO2 54.2%, Al2O3 18.9%, ZnO 7.5%, CaO 3.1%, MgO 2.5%, K2O 3.7%, Na2O 3.4%, BaO 1.3%, and L.O.I 5.4%.

[0074] Example 5 In this example, all conditions were the same as in Example 2, except that a dry granule protective glaze slurry was applied to the surface of the sapphire dry granule layer. The dry granule protective glaze slurry included 51% of protective dry granules and 49% of 9022A dry granule suspending agent; By weight, the protective dry granules included the following components: 23 parts of potassium feldspar, 5 parts of calcined alumina, 11 parts of kaolin, 7 parts of zinc oxide, and 10 parts of quartz. The chemical composition of the protective dry granules, by mass percentage, included: SiO2 59.9%, Al2O3 17.8%, K2O 5.2%, ZnO 10.9%, and L.O.I 6.2%.

[0075] After the raw materials of the protective dry granules were mixed evenly, they were melted at 1370 °C, then quenched with water, ground, and passed through a 325-mesh sieve with a residue of 0.1-0.4% to obtain the protective dry granules.

[0076] The pattern texture clarity and glaze surface effect of the tiles prepared in Examples 4-5 were observed, and the specific test results are shown in Table 7.

[0077] Table 7 As can be seen from Table 7, as the results of Example 1 and Example 4 show, the underglaze provided by this solution has a better fusion degree at the joint surface between the underglaze and the sapphire effect dry particles, and has the function of promoting color development, with a better imitation sapphire effect. As the results of Example 2 and Example 5 show, the dry particle protective glaze of this solution forms a jade-like wrapping feeling for the blue crystals, making the glaze surface have a visual effect similar to gemstone inlay and a stronger sense of transparency.

[0078] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the content of the specification of the present invention under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A sapphire-effect dry granule, characterized in that, Based on the total weight of the sapphire-effect dry granules being 100%, the sapphire-effect dry granules include: 85 - 90% of blue dry granules and 10 - 15% of transparent dry granules; The preparation raw materials of the blue dry granules include the following components by weight: 1.5 - 3.5 parts of ultrafine tin dioxide, 15 - 19.5 parts of cobalt oxide, 4.5 - 7.5 parts of titanium oxide, 8 - 14 parts of zinc oxide, 32 - 43 parts of calcined alumina, 8 - 13 parts of quartz, 10 - 16 parts of potassium feldspar, and 2.5 - 4.5 parts of boric acid; The preparation raw materials of the transparent dry granules include the following components by weight: 8 - 15 parts of zinc oxide, 5 - 10 parts of alumina, 24 - 28 parts of quartz, 1 - 2.5 parts of nano silicon nitride, and 7 - 11 parts of cryolite.

2. The sapphire effect dry granules according to claim 1, characterized in that, By mass percentage: The chemical composition of the blue dry granules includes: SiO2 10.3 - 16.2%, Al2O3 35.3 - 46.2%, SnO2 1.6 - 4.2%, K2O 1.9 - 3.6%, ZnO 8.6 - 13.7%, B2O3 1.5 - 2.7%, CoO 14.3 - 22.3%, TiO2 5.9 - 12.6%, and L.O.I 2.4 - 5.8%; The chemical composition of the transparent dry granules includes: SiO2 45.3 - 56.2%, Al2O3 8.3 - 16.6%, ZnO 12.6 - 23.7%, Si3N4 1.6 - 4.2%, NaF 3.6 - 7.7%, and L.O.I 4.4 - 6.8%.

3. The sapphire effect dry granules according to claim 1, characterized in that, The blue dry granules are obtained by melting the raw materials at 1250 - 1350 °C and then quenching and grinding them. The particle size distribution is: 45 - 60% for 10 - 20 mesh, 25 - 30% for 20 - 40 mesh, and 12 - 30% for 40 - 80 mesh; The transparent dry granules are obtained by melting the raw materials at 1300 - 1450 °C and then quenching and grinding them, and the particle size is 400 - 600 mesh.

4. A tile with a sapphire-like effect, characterized in that, It successively includes a green body layer, an underglaze layer, a pattern layer, a sapphire dry granule layer, and a dry granule protective glaze layer; The sapphire dry granule layer is prepared from the sapphire-effect dry granules as described in any one of claims 1 - 3.

5. The ceramic tile with sapphire-like effect according to claim 4, wherein The dry granule protective glaze layer is obtained from the dry granule protective glaze slurry; Based on the total weight of the dry granule protective glaze slurry being 100%, the dry granule protective glaze slurry includes 50 - 55% of protective dry granules and 45 - 50% of dry granule suspending agent; The preparation raw materials of the protective dry granules include the following components by weight: 23 - 27 parts of potassium feldspar, 3 - 5 parts of calcined alumina, 10 - 15 parts of kaolin, 4 - 8 parts of zinc oxide, and 8 - 13 parts of quartz; The chemical composition of the protective dry granules by mass percentage includes: SiO2 59.6 - 64.3%, Al2O3 14.9 - 18.6%, K2O 3.5 - 5.9%, ZnO 6.5 - 11.2%, and L.O.I 4.1 - 7.5%.

6. The tile with sapphire-like effect according to claim 4, wherein The protective dry granules are obtained by melting the raw materials at 1300 - 1450 °C and then quenching and grinding them.

7. The tile with sapphire-like effect according to claim 4, wherein, The raw materials for preparing the bottom glaze layer include the following components by weight: 5-10 parts of zinc oxide, 1-3 parts of barium carbonate, 15-20 parts of potassium feldspar, 10-15 parts of sodium feldspar, 1.5-3.5 parts of calcined talc, 1-3.5 parts of calcite, 13-19 parts of quartz, 5-8 parts of dolomite, 7-11 parts of calcined kaolin, 8.5-12 parts of washed kaolin, and 6-12 parts of alumina; The chemical composition of the bottom glaze layer, by mass percentage, includes: SiO2 48.1-56.3%, Al2O3 16.3-19.1%, ZnO 5.9-10.7%, CaO 2.3-3.9%, MgO 1.9-4.8%, K2O 3.5-4.8%, Na2O 3.3-4.7%, BaO 0.6-1.6%, and L.O.I 2.3-5.9%.

8. The tile with sapphire-like effect according to claim 4, characterized in that, The raw materials for preparing the green body layer include the following components by weight: 9.5-11.5 parts of raw ore mud, 1.3-3.5 parts of bentonite, 6.6-9.5 parts of kaolin, 8.5-11.5 parts of washed mud, 33.5-38.3 parts of stone powder, 16.2-22.3 parts of high-aluminum potassium sand, and 1-3 parts of talc; The chemical composition of the green body layer, by mass percentage, includes: SiO2 60.3-67.3%, Al2O3 19.7-23.2%, CaO 1.1-2.5%, MgO 0.2-0.8%, K2O 2.3-4.5%, Na2O 0.6-1.3%, Fe2O3 0.2-0.6%, and L.O.I 3.3-7.6%.

9. The preparation method of the tile with sapphire-like effect according to any one of claims 4 to 8, characterized in that, It includes the following steps: S1. Prepare the green body to obtain the green body layer; S2. Apply the bottom glaze on the surface of the green body layer to obtain the bottom glaze layer; S3. Inkjet print a color pattern on the surface of the bottom glaze layer to obtain the pattern layer; S4. After inkjet printing the positioning glue on the surface of the pattern layer, apply the sapphire effect dry particles to obtain the sapphire dry particle layer; S5. Apply the dry particle protective glaze slurry on the surface of the sapphire dry particle layer to obtain the dry particle protective glaze layer; S6. Send it into the kiln for firing to obtain the tile with the imitation sapphire effect.

10. The preparation method according to claim 9, characterized in that, In step S6, the firing process includes: Preheating stage: The heating rate is 25-35 °C / min, and the temperature range is from room temperature to 350 °C; Oxidation and decomposition stage: The heating rate is 30-40 °C / min, and the temperature range is 350-950 °C; High-temperature stage: The heating rate is 20-25 °C / min, and the temperature range is 950 °C to the maximum firing temperature; High-fire holding stage: The time is 2-5 min; And the cooling stage: The cooling rate in the temperature range from the maximum firing temperature to 600 °C is 25-35 °C / min; the cooling rate in the temperature range from 600 to 500 °C is 15-20 °C / min; the cooling rate in the temperature range from 500 °C to room temperature is 35-40 °C / min; The maximum firing temperature is 1150-1210 °C.

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