Composite zircon white opacifying frit, preparation method thereof, and super-white glaze and ceramic tile using the same

Abstract

The present application relates to the technical field of glaze, and particularly relates to a composite zircon white opal frit, a preparation method thereof, super-white glaze using the composite zircon white opal frit and ceramic tile. The raw materials of the composite zircon white opal frit include, in terms of weight parts, quartz 25-40 parts, calcined alumina 5-10 parts, potassium feldspar 20-35 parts, talc 3-10 parts, calcite 5-10 parts, calcium phosphate 5-10 parts, calcined shell 1-5 parts, zirconium boride 7-15 parts, zirconite sand 3-10 parts, kaolin 1-5 parts and zinc oxide 3-10 parts. The raw materials of the composite zircon white opal frit described above can make the composite zircon white opal frit have a high whitening effect; meanwhile, two cooling and holding processes are adopted in the cooling and holding stage, the content of SiO2, P2O5 and MgO in the chemical composition of the composite zircon white opal frit is adjusted, a large amount of fine needle-like MgSiO3 can be generated, and the opalescence and whiteness of the glaze are improved after the obtained composite opal frit is used in the glaze.

Description

Technical Field

[0001] This invention relates to the field of glaze technology, and in particular to a composite zirconium white opaque frit and its preparation method, an ultra-white glaze using the composite zirconium white opaque frit, and ceramic tiles. Background Technology

[0002] In the ceramic tile production process, to make the surface patterns more vibrant, a layer of white glaze is usually applied to the surface of the ceramic green body before inkjet printing the pattern. This white glaze uses a ceramic opacifier—zirconium silicate. Currently, the amount of zirconium silicate added to ceramic tile raw materials is often 10-15%, which can control the whiteness of the glaze to above 75 degrees. When producing top-grade marble tiles such as Carrara White, the amount of zirconium silicate added is even increased to about 20% to achieve even higher whiteness; however, after the amount of zirconium silicate reaches 15%, the effect on improving the whiteness of the glaze tends to saturate, and although the amount of zirconium silicate added increases, the effect on improving whiteness is not significant.

[0003] Due to the limited global supply and rising price of zircon sand, the raw material for zirconium silicate, ceramic enterprises face increased production costs. Furthermore, when a large amount of zirconium silicate is added, ceramic tiles produced using it as a glaze often exhibit radioactivity because zirconium silicate contains certain amounts of the radioactive elements radium and thorium, which is detrimental to the home environment. Summary of the Invention

[0004] The main objective of this invention is to provide a composite zirconium white emulsion frit and its preparation method, as well as an ultra-white glaze and ceramic brick using the composite zirconium white emulsion frit. This invention aims to improve the existing technical problems of poor whiteness enhancement effect of glazes using zirconium silicate as a whitening raw material, which also have high production costs.

[0005] To achieve the above objectives, the present invention proposes a composite zirconium white opaque frit, wherein the raw materials of the composite zirconium white opaque frit, by weight, include: 25-40 parts of quartz, 5-10 parts of calcined alumina, 20-35 parts of potassium feldspar, 3-10 parts of talc, 5-10 parts of calcite, 5-10 parts of calcium phosphate, 1-5 parts of calcined shells, 7-15 parts of zirconium boride, 3-10 parts of zircon sand, 1-5 parts of kaolin, and 3-10 parts of zinc oxide.

[0006] This invention utilizes a blend of quartz, calcined alumina, potassium feldspar, talc, calcite, calcium phosphate, calcined shells, zirconium boride, zircon sand, kaolin, and zinc oxide to produce a zirconium white opaque frit with high whiteness. When used in ceramic tiles, this frit can achieve a glaze whiteness of over 85°. Furthermore, it significantly reduces costs compared to using zirconium silicate alone as a whitening agent. The zirconium boride and zircon sand selected in this invention enhance the whiteness of the frit, while calcium phosphate and calcined shells increase the opacity of the frit. Additionally, the flux materials—potassium feldspar, calcite, talc, and zinc oxide—reduce the high-temperature viscosity of the frit, causing the zirconium white opaque frit to precipitate zinc siliceous mineral (2ZnO•SiO2, belonging to the triclinic system, white and radially distributed) after high-temperature firing, while retaining a large amount of quartz particles and their variants, forming a mixed opaque phase in the glaze, ultimately leading to devitrification and further improving whiteness.

[0007] The aforementioned calcined shells refer to calcined shell powder or calcined snail shell powder.

[0008] Preferably, the chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 45-60%, Al2O3 10-15%, CaO 5-8%, MgO 1-2%, K2O 2-4%, Na2O 0.6-1%, ZrO2 7-15%, P2O5 1.4-3%, ZnO 2-9%, Fe2O3 0.01-0.05%, and TiO2 0.01-0.05%. Furthermore, the composite zirconium white opaque frit also contains some loss on ignition and a small amount of impurities. When the chemical composition of the composite zirconium white opaque frit is within the above range, it exhibits better characteristics, with superior whiteness and other properties.

[0009] This invention also proposes a method for preparing the composite zirconium white opaque frit as described in any one of the above claims, comprising the following steps: uniformly mixing the raw materials for the composite zirconium white opaque frit and calcining them; then quenching the calcined glass melt in cold water to obtain the composite zirconium white opaque frit. The composite zirconium white opaque frit is obtained through calcination and water quenching; the preparation method is simple and the production cost is low.

[0010] Preferably, the calcination process is as follows: the temperature is increased from room temperature to 530-600℃ at a rate of 6-8℃ / min, then increased to 1000-1200℃ at a rate of 3-5℃ / min, then increased to 1450-1550℃ at a rate of 9-10℃ / min, then decreased to 1400-1420℃ at a rate of 12-14℃ / min, held for 30-37min, and then decreased to 1150-1250℃ at a rate of 5-10℃ / min, held for 25-40min.

[0011] During firing, the frit often undergoes a process of crystal growth and dissolution. For example, at high temperatures, some of the crystals begin to dissolve, and during cooling, the remaining microcrystals become nuclei and precipitate crystals. Therefore, to obtain a well-crystallized frit during firing, it is necessary to maintain a high temperature for a long time in the temperature range where nucleation and crystal growth occur, thereby achieving a whitening effect. Therefore, this solution breaks away from the traditional single cooling and holding process in the cooling and holding stages, adjusting it to two cooling and holding processes as described above, followed by furnace cooling. Combined with the chemical composition of the aforementioned composite zirconium white frit, which alters the content of SiO2, P2O5, and MgO, a large number of fine needle-like MgSiO3 are generated during the cooling-holding-cooling process. When the resulting composite frit is used in glazes, both the opacity and whiteness of the glaze are improved.

[0012] This invention also proposes an ultra-white glaze, which, by weight, is prepared from the following raw materials: 10-30 parts modified quartz, 20-40 parts potassium feldspar, 5-15 parts kaolin, 20-40 parts of the composite zirconium white opaque frit as described above, 1-5 parts wollastonite, 5-10 parts alumina, and 5-15 parts polyacrylamide gel. This invention, by compounding the above-prepared composite zirconium white opaque frit with modified quartz, potassium feldspar, kaolin, wollastonite, and alumina, produces an ultra-white glaze with excellent smoothness. Due to the use of the composite zirconium white opaque frit in the raw materials, the glaze exhibits high whiteness in ceramic tiles. Furthermore, the use of polyacrylamide gel as a dispersant ensures thorough mixing of the raw materials, improving the glaze's performance. Because the amount of zircon sand added to the composite zircon white emulsion frit is relatively small, and the amount of the composite zircon white emulsion frit added to the glaze is also small, only a thin layer of ultra-white glaze needs to be sprayed on the surface glaze to achieve a significant whitening effect. Compared with the traditional method of directly adding about 15% zirconium silicate to the surface glaze raw material, the whitening cost will be much lower. At the same time, the ultra-white glaze produced has no risk of exceeding the radioactivity standard, which is beneficial to the home environment.

[0013] Preferably, the preparation steps of the modified quartz include: adding 5-10% titanium dioxide to 90-95% quartz sand by mass percentage, mixing evenly, and then sintering to obtain the modified quartz; wherein the sintering temperature is 1300-1400℃, and the sintering time is 0.5-1h. Adding titanium dioxide to the quartz sand allows it to be fully mixed and coated on the surface of the quartz sand. The sintering process then evenly solidifies the titanium dioxide on the surface of the quartz sand, effectively reducing the light transmittance of the quartz sand and further improving the whiteness of the glaze.

[0014] Preferably, the preparation steps of the ultra-white glaze include: adding the raw materials of the ultra-white glaze into a ball mill, then adding 35-40% water, 0.25-0.35% carboxymethyl cellulose, and 0.3-0.4% sodium tripolyphosphate by weight of the raw materials of the ultra-white glaze, and ball milling for 10-12 hours. The fineness of the glaze slurry after ball milling is 0.2%-0.4% residue on a 325-mesh sieve, with a specific gravity of 1.80-1.85 g / ml and a flow rate of 60-80 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained.

[0015] This invention proposes a ceramic tile using an ultra-white glaze as described in any of the above claims, wherein the ceramic tile is fired at a temperature of 1180-1210℃. After applying the aforementioned ultra-white glaze to the ceramic tile, and then firing it at 1180-1210℃, the resulting ceramic tile exhibits both high whiteness and good quality. The preparation process of this glaze and ceramic tile is simple, with little difference from existing ceramic tile production processes, and can be produced using existing equipment, which is beneficial for mass production.

[0016] Preferably, the ultra-white glaze is applied to the surface glaze of the ceramic tile, and the specific gravity of the ultra-white glaze is adjusted to 1.35-1.40 g / ml during application. The aforementioned ultra-white glaze is sprayed onto the surface of the ordinary glaze of the ceramic tile using a spraying method, thus achieving a whitening effect. In actual use, the specific gravity of the ultra-white glaze needs to be adjusted; an adjustment to 1.35-1.40 g / ml yields the best results.

[0017] Preferably, the whiteness of the ceramic tile is above 85°. After adjusting the raw materials and preparation process as described above, the obtained ceramic tile, due to the application of ultra-white glaze, has a whiteness of at least 85°.

[0018] Compared with the prior art, the composite zirconium white emulsion frit, ultra-white glaze, and ceramic tile of the present invention have the following beneficial effects:

[0019] 1. The zirconium boride and zircon sand in the composite zirconium white opaque frit can improve the whiteness of the frit. At the same time, the calcium phosphate and calcined shells in the raw materials can increase the opacity of the frit material. The solvent materials - potassium feldspar, calcite, talc and zinc oxide - reduce the high-temperature viscosity of the frit. After the zirconium white opaque frit is fired at high temperature, zinc siliceous minerals are precipitated, and a large amount of quartz particles and their variants are left over, forming a mixed opaque phase in the glaze, which eventually becomes opaque and further improves the whiteness.

[0020] 2. This scheme employs two cooling and holding processes during the cooling and holding stages, followed by furnace cooling. This alters the content of SiO2, P2O5, and MgO in the chemical composition of the composite zircon white opaque frit, allowing a large number of fine needle-like MgSiO3 to be generated during the cooling-holding-cooling process. When the obtained composite opaque frit is used in glazes, both the opacity and whiteness of the glazes are improved.

[0021] 3. The ultra-white glaze uses composite zirconium white emulsion frit, which gives the glaze a high whiteness in ceramic tiles. Titanium dioxide is added to the quartz sand, which is fully mixed with the quartz sand and coated on the surface of the quartz sand. Then, through the sintering process, the titanium dioxide is uniformly solidified on the surface of the quartz sand, which can effectively reduce the light transmittance of the quartz sand and further improve the whiteness of the glaze / ceramic tile. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] A method for preparing a composite zircon white opaque frit includes the following steps: 25-40 parts of quartz, 5-10 parts of calcined alumina, 20-35 parts of potassium feldspar, 3-10 parts of talc, 5-10 parts of calcite, 5-10 parts of calcium phosphate, 1-5 parts of calcined shell, 7-15 parts of zirconium boride, 3-10 parts of zircon sand, 1-5 parts of kaolin, and 3-10 parts of zinc oxide are mixed evenly and then calcined. The calcination process involves heating from room temperature to 530-600℃ at a rate of 6-8℃ / min, and then heating to 10℃ at a rate of 3-5℃ / min. The temperature is increased from 00-1200℃ to 1450-1550℃ at a rate of 9-10℃ / min, then decreased to 1400-1420℃ at a rate of 12-14℃ / min and held for 30-37 min. The temperature is then decreased to 1150-1250℃ at a rate of 5-10℃ / min and held for 25-40 min. The calcined glass melt is then quenched in cold water (the quenching temperature is below 50℃, generally using room temperature water of about 25℃, and the quenching time is 0.1-1h) to obtain the composite zirconium white opaque frit.

[0025] The chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 45-60%, Al2O3 10-15%, CaO 5-8%, MgO 1-2%, K2O 2-4%, Na2O 0.6-1%, ZrO2 7-15%, P2O5 1.4-3%, ZnO 2-9%, Fe2O3 0.01-0.05%, and TiO2 0.01-0.05%.

[0026] A method for preparing an ultra-white glaze includes the following steps: 10-30 parts of modified quartz, 20-40 parts of potassium feldspar, 5-15 parts of kaolin, 20-40 parts of composite zirconium white emulsion frit, 1-5 parts of wollastonite, 5-10 parts of alumina, and 5-15 parts of polyacrylamide gel are added to a ball mill. Then, 35-40% of the total weight of the above ultra-white glaze raw materials (water), 0.25-0.35% of carboxymethyl cellulose, and 0.3-0.4% of sodium tripolyphosphate are added. The mixture is ball-milled for 10-12 hours. The fineness of the glaze slurry after ball milling is 0.2%-0.4% residue on a 325-mesh sieve, with a specific gravity of 1.80-1.85 g / ml and a flow rate of 60-80 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained.

[0027] The preparation steps of the modified quartz include: adding 5-10% titanium dioxide to 90-95% quartz sand by mass percentage, mixing evenly, and then sintering to obtain the modified quartz; wherein the sintering temperature is 1300-1400℃ and the sintering time is 0.5-1h.

[0028] A ceramic tile, wherein the above-mentioned ultra-white glaze is sprayed onto the surface glaze of the ceramic tile, wherein the specific gravity of the ultra-white glaze is adjusted to 1.35-1.40 g / ml when applied, and the firing temperature of the ceramic tile is 1180-1210℃.

[0029] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0030] The following examples or comparative examples all use the same ceramic tile preparation process, only the ultra-white glaze and the composite zircon white emulsion frit are different. The preparation process includes the following steps: pressing conventional ceramic blanks into blanks — applying a surface glaze to the blanks — spraying ultra-white glaze (containing composite zircon white emulsion frit) onto the surface glaze — then inkjet printing a pattern — applying and polishing glaze — and then firing at high temperature in a kiln to obtain ceramic tiles.

[0031] The following examples and comparative examples provide specific formulations for ceramic blanks, surface glazes, and polished glazes.

[0032] By weight, the above ceramic blanks include the following raw materials: 3-10 parts (8 parts) of high white sand, 20-28 parts (25 parts) of potassium aluminate sand, 20-25 parts (22 parts) of washed clay, 6-13 parts (10 parts) of high alumina potassium stone powder, 3-8 parts (6 parts) of high sodium sand, 8-15 parts (11 parts) of black mud, 25-33 parts (28 parts) of sodium sand and 6-10 parts (8 parts) of high white clay.

[0033] By weight, the above-mentioned glaze comprises the following raw materials: 25-35 parts (30 parts) of potassium feldspar, 5-10 parts (7 parts) of sodium feldspar, 10-15 parts (12 parts) of calcined alumina, 7-10 parts (9 parts) of kaolin, 20-30 parts (23 parts) of quartz, 3-5 parts (4 parts) of double-flying powder, 3-8 parts (6 parts) of diopside, 3-8 parts (6 parts) of nepheline, and 3-5 parts (3 parts) of zirconium silicate.

[0034] By weight, the above polishing glaze includes the following raw materials: 40-50 parts (43 parts) of potassium feldspar, 3-5 parts (4 parts) of quartz, 2-5 parts (3 parts) of wollastonite, 5-8 parts (6 parts) of talc, 3-5 parts (3 parts) of calcined alumina, 5-10 parts (8 parts) of kaolin, 1-5 parts (4 parts) of zinc oxide, 2-5 parts (3 parts) of barium carbonate, 8-10 parts (9 parts) of strontium carbonate, and 15-20 parts (17 parts) of dolomite.

[0035] Example 1

[0036] The preparation method of composite zircon white opaque frit includes the following steps: 25 parts of quartz, 7 parts of calcined alumina, 30 parts of potassium feldspar, 9 parts of talc, 10 parts of calcite, 5 parts of calcium phosphate, 2 parts of calcined shell, 7 parts of zirconium boride, 9 parts of zircon sand, 5 parts of kaolin, and 8 parts of zinc oxide are mixed evenly and then calcined. This embodiment adopts a traditional calcination process, such as the cooling and holding process in patent number CN113372002A. Specifically, the temperature is increased from room temperature to 290°C at a rate of 3°C / min, then increased to 1200°C at a rate of 9°C / min, then increased to 1530°C at a rate of 5°C / min, and then cooled to 1450°C at a rate of 12°C / min and held for 20 minutes. The calcined glass melt is then quenched in cold water to obtain the composite zircon white opaque frit. The chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 50.57%, Al2O3 11.92%, CaO 7.15%, MgO 1.54%, K2O 2.36%, Na2O 0.76%, ZrO2 10.59%, P2O5 1.49%, ZnO 6.77%, Fe2O3 0.02%, TiO2 0.03%, and IL (loss on ignition) 6.21%.

[0037] The preparation method of the ultra-white glaze includes the following steps: 27 parts modified quartz, 29 parts potassium feldspar, 15 parts kaolin, 28 parts composite zirconium white emulsion frit, 4 parts wollastonite, 10 parts alumina, and 10 parts polyacrylamide gel are added to a ball mill. Then, water (40% of the total weight of the above ultra-white glaze raw materials), 0.25% carboxymethyl cellulose, and 0.4% sodium tripolyphosphate are added, and the mixture is ball-milled for 12 hours. The fineness of the glaze slurry after ball milling is 0.3% residue on a 325-mesh sieve, a specific gravity of 1.82 g / ml, and a flow rate of 65 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained. The preparation step of the modified quartz includes: adding 7% titanium dioxide to 93% quartz sand, mixing evenly, and then sintering at a sintering temperature of 1380℃ for 1 hour to obtain the modified quartz.

[0038] During the preparation of this ceramic tile, the aforementioned ultra-white glaze is sprayed onto the surface glaze of the ceramic tile. The specific gravity of the ultra-white glaze is adjusted to 1.40 g / ml when applied, and the firing temperature of the ceramic tile is 1200℃.

[0039] Example 2

[0040] The preparation method of composite zircon white opaque frit includes the following steps: 25 parts of quartz, 9 parts of calcined alumina, 32 parts of potassium feldspar, 5 parts of talc, 6 parts of calcite, 10 parts of calcium phosphate, 1 part of calcined shell, 12 parts of zirconium boride, 10 parts of zircon sand, 4 parts of kaolin, and 10 parts of zinc oxide are mixed evenly and then calcined. This embodiment adopts a traditional calcination process, such as the cooling and holding process in patent number CN113372002 A. Specifically, the temperature is increased from room temperature to 310°C at a rate of 4°C / min, then increased to 1100°C at a rate of 10°C / min, then increased to 1500°C at a rate of 7°C / min, and then cooled to 1400°C at a rate of 15°C / min and held for 40 min. The calcined glass melt is then quenched in cold water to obtain the composite zircon white opaque frit. The chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 46.95%, Al2O3 13.02%, CaO 6.17%, MgO 0.81%, K2O 3.38%, Na2O 0.77%, ZrO2 14.08%, P2O5 2.81%, ZnO 7.92%, Fe2O3 0.04%, TiO2 0.01%, and IL 4.01%.

[0041] The preparation method of the ultra-white glaze includes the following steps: 10 parts modified quartz, 40 parts potassium feldspar, 12 parts kaolin, 20 parts composite zirconium white emulsion frit, 1 part wollastonite, 7 parts alumina, and 12 parts polyacrylamide gel are added to a ball mill. Then, 35% water, 0.3% carboxymethyl cellulose, and 0.4% sodium tripolyphosphate (by weight of the above raw materials) are added, and the mixture is ball-milled for 10 hours. The fineness of the glaze slurry after ball milling is 0.4% residue on a 325-mesh sieve, with a specific gravity of 1.83 g / ml and a flow rate of 68 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained. The preparation step of the modified quartz includes: adding 5% titanium dioxide to 95% quartz sand, mixing evenly, and then sintering at a sintering temperature of 1320℃ for 0.8 hours to obtain the modified quartz.

[0042] During the preparation of this ceramic tile, the aforementioned ultra-white glaze is sprayed onto the surface glaze of the ceramic tile. The specific gravity of the ultra-white glaze is adjusted to 1.38 g / ml when applied, and the firing temperature of the ceramic tile is 1180℃.

[0043] Example 3

[0044] The preparation method of composite zircon white opaque frit includes the following steps: 40 parts of quartz, 5 parts of calcined alumina, 20 parts of potassium feldspar, 3 parts of talc, 5 parts of calcite, 6 parts of calcium phosphate, 2 parts of calcined shell, 8 parts of zirconium boride, 3 parts of zircon sand, 3 parts of kaolin, and 5 parts of zinc oxide are mixed evenly and then calcined. This embodiment adopts a traditional calcination process, such as the cooling and holding process in patent number CN113372002A. Specifically, the temperature is increased from room temperature to 280°C at a rate of 3°C / min, then increased to 1050°C at a rate of 8°C / min, then increased to 1550°C at a rate of 8°C / min, and then cooled to 1380°C at a rate of 13°C / min and held for 30 min. The calcined glass melt is then quenched in cold water to obtain the composite zircon white opaque frit. The chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 58.62%, Al2O3 9.53%, CaO 5.78%, MgO 0.61%, K2O 1.85%, Na2O 0.61%, ZrO2 9.29%, P2O5 2.14%, ZnO 4.95%, Fe2O3 0.01%, TiO2 0.02%, and IL 6.02%.

[0045] The preparation method of the ultra-white glaze includes the following steps: 15 parts of quartz, 38 parts of potassium feldspar, 5 parts of kaolin, 40 parts of composite zircon white emulsion frit, 3 parts of wollastonite, 5 parts of alumina, and 15 parts of polyacrylamide gel are added to a ball mill. Then, 38% of the total weight of the above ultra-white glaze raw materials, 0.3% of carboxymethyl cellulose, and 0.3% of sodium tripolyphosphate are added and the mixture is ball-milled for 12 hours. The fineness of the glaze slurry after ball milling is 0.2% residue on a 325-mesh sieve, with a specific gravity of 1.85 g / ml and a flow rate of 70 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained.

[0046] During the preparation of this ceramic tile, the aforementioned ultra-white glaze is sprayed onto the surface glaze of the ceramic tile. The specific gravity of the ultra-white glaze is adjusted to 1.35 g / ml when applied, and the firing temperature of the ceramic tile is 1190℃.

[0047] Example 4

[0048] The preparation method of composite zircon white opaque frit includes the following steps: 35 parts of quartz, 6 parts of calcined alumina, 25 parts of potassium feldspar, 4 parts of talc, 5 parts of calcined calcined calcined shell, 7 parts of zirconium boride, 6 parts of zircon sand, 1 part of kaolin, and 3 parts of zinc oxide are mixed evenly and then calcined. This embodiment adopts a traditional calcination process, such as the cooling and holding process in patent number CN113372002A. Specifically, the temperature is increased from room temperature to 300°C at a rate of 5°C / min, then increased to 1080°C at a rate of 9°C / min, then increased to 1600°C at a rate of 6°C / min, and then cooled to 1420°C at a rate of 10°C / min and held for 25 min. The calcined glass melt is then quenched in cold water to obtain the composite zircon white opaque frit. The chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 55.85%, Al2O3 10.42%, CaO 7.67%, MgO 0.78%, K2O 2.21%, Na2O 0.73%, ZrO2 9.98%, P2O5 2.36%, ZnO 2.88%, Fe2O3 0.03%, TiO2 0.04%, and IL 6.68%.

[0049] The preparation method of the ultra-white glaze includes the following steps: 30 parts modified quartz, 22 parts potassium feldspar, 10 parts kaolin, 24 parts composite zirconium white emulsion frit, 5 parts wollastonite, 8 parts alumina, and 6 parts polyacrylamide gel are added to a ball mill. Then, water (40% of the total weight of the above ultra-white glaze raw materials), 0.35% carboxymethyl cellulose, and 0.3% sodium tripolyphosphate are added, and the mixture is ball-milled for 11 hours. The fineness of the glaze slurry after ball milling is 0.3% residue on a 325-mesh sieve, a specific gravity of 1.8 g / ml, and a flow rate of 75 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained. The preparation step of the modified quartz includes: adding 9% titanium dioxide to 91% quartz sand, mixing evenly, and then sintering at a sintering temperature of 1350℃ for 0.6 hours to obtain the modified quartz.

[0050] During the preparation of this ceramic tile, the aforementioned ultra-white glaze is sprayed onto the surface glaze of the ceramic tile. The specific gravity of the ultra-white glaze is adjusted to 1.39 g / ml when applied, and the firing temperature of the ceramic tile is 1210℃.

[0051] Comparative Example 1

[0052] This comparative example uses existing zirconium silicate as the raw material for the whitening glaze. By weight, the raw materials of this whitening glaze include: 35 parts potassium feldspar, 10 parts nepheline, 7 parts kaolin, 20 parts quartz, 15 parts alumina, 3 parts talc, and 15 parts zirconium silicate. The steps for preparing ceramic tiles using this glaze and the method of applying the glaze are the same as in Example 1.

[0053] Comparative Example 2

[0054] In this comparative example, all preparation steps and parameters are the same as in Example 1, except that zirconium boride is not added to the raw materials of the composite zirconium white opaque frit.

[0055] Comparative Example 3

[0056] In this comparative example, all preparation steps and parameters are the same as in Example 1, except that calcium phosphate and calcined shell are not added to the raw materials of the composite zirconium white opaque frit.

[0057] Comparative Example 4

[0058] In this comparative example, all preparation steps and parameters are the same as in Example 1, except that talc is not added to the raw materials of the composite zircon white opaque frit.

[0059] The ceramic tiles prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance testing. The specific test results are shown in the table below:

[0060]

[0061] Note: 1. In this solution, surface flatness specifically refers to the center curvature of the ceramic tile. Center curvature is the curvature of the center relative to the diagonal calculated from the working dimension. In the value of center curvature, + indicates convex deformation. It indicates a concave deformation.

[0062] 2. According to GB / T 3810.2 2016 Ceramic Tile Test Methods Part 2: Inspection of Dimensions and Surface Quality - Measuring the flatness of ceramic tiles.

[0063] As shown in the test results in the table above, as in Examples 1-4, the ceramic tiles in this scheme have a whiteness of over 85°, a gloss of around 28-30°, and a surface flatness of less than 0.6. Furthermore, the ceramic tiles exhibit good glaze quality. Example 3, due to the absence of modified quartz and the use of a traditional calcination process, exhibits a small number of pinholes in its glaze (significantly fewer than in Comparative Examples 3-4).

[0064] The test results of Example 1 and Comparative Example 1 show that, using traditional zirconium silicate as a whitening raw material, even with an addition amount of 15 parts of zirconium silicate, the whiteness of the resulting ceramic tiles only reached about 75 degrees, and the surface smoothness was inferior to that of the ceramic tiles produced in this scheme. The test results of Example 1 and Comparative Example 2 show that when zirconium boride was not added to the composite zirconium white emulsion frit, both whiteness and tile smoothness decreased. The test results of Example 1 and Comparative Example 3 show that when calcium phosphate and calcined shell were not added to the composite zirconium white emulsion frit, both whiteness and tile smoothness decreased to varying degrees, and some pinholes appeared on the glaze of the ceramic tiles. The test results of Example 1 and Comparative Example 4 show that when talc was not added to the composite zirconium white emulsion frit, both whiteness and tile smoothness decreased, and some pinholes appeared on the glaze of the ceramic tiles.

[0065] Example 5

[0066] In this embodiment, all conditions are the same as in Example 1. The difference is that the calcination steps and parameters during the preparation of the composite zirconium white opaque frit are adjusted. Specifically, the temperature is increased from room temperature to 580°C at a rate of 6°C / min, then increased to 1200°C at a rate of 4°C / min, then increased to 1500°C at a rate of 10°C / min, then decreased to 1410°C at a rate of 12°C / min and held for 35 min, and then decreased to 1200°C at a rate of 6°C / min and held for 35 min.

[0067] Example 6

[0068] In this embodiment, all conditions are the same as in Example 3. The difference is that the calcination steps and parameters during the preparation of the composite zirconium white opaque frit are adjusted. Specifically, the temperature is increased from room temperature to 550°C at a rate of 7°C / min, then increased to 1150°C at a rate of 5°C / min, then increased to 1480°C at a rate of 9°C / min, then decreased to 1415°C at a rate of 14°C / min and held for 33 min, and then decreased to 1175°C at a rate of 8°C / min and held for 30 min.

[0069] The ceramic tiles prepared in Examples 5-6 were subjected to performance testing, and the specific test results are shown in the table below:

[0070]

[0071] The test results of Examples 1 and 5, and Examples 3 and 6 show that after adjusting the traditional single cooling and heat preservation process to the double cooling and heat preservation process in this scheme (with the other calcination parameters also being adjusted simultaneously), the whiteness of the ceramic tiles has been improved.

[0072] Example 7

[0073] In this embodiment, all conditions are the same as in Example 6, except that a preferred chemical composition is used. The raw materials for the composite zircon white opaque frit include: 28 parts quartz, 7 parts calcined alumina, 30 parts potassium feldspar, 6 parts talc, 7 parts calcite, 7 parts calcium phosphate, 3 parts calcined shells, 10 parts zirconium boride, 5 parts zircon sand, 3 parts kaolin, and 6 parts zinc oxide. The corresponding chemical composition includes: SiO2 51.12%, Al2O3 11.74%, CaO 7.19%, MgO 1.07%, K2O 2.47%, Na2O 0.81%, ZrO2 11.12%, P2O5 2.19%, ZnO 5.35%, Fe2O3 0.02%, TiO2 0.02%, and IL 6.31%.

[0074] The ceramic bricks prepared in Example 7 were subjected to performance testing, and the specific test results are shown in the table below:

[0075]

[0076] The test results of Examples 6 and 7 show that the whiteness of ceramic tiles can be further improved by adjusting the amount of each raw material in the composite zircon white emulsion frit and limiting the content of SiO2, P2O5 and MgO.

[0077] Example 8

[0078] In this embodiment, all conditions are the same as in Example 6, except that the quartz used in Example 8 is modified quartz. The preparation steps of modified quartz include: adding titanium dioxide to quartz sand, mixing evenly, and then sintering to obtain the modified quartz.

[0079] The ceramic bricks prepared in Example 8 were subjected to performance testing, and the specific test results are shown in the table below:

[0080]

[0081] The test results of Examples 6 and 8 show that when the conventional quartz in the ultra-white glaze is replaced with the modified quartz in this solution, the whiteness of the ceramic tile is improved to some extent. In addition, the surface flatness of the ceramic tile is better.

[0082] Example 9

[0083] The preparation method of composite zircon white opaque frit includes the following steps: 35 parts of quartz, 8 parts of calcined alumina, 27 parts of potassium feldspar, 5 parts of talc, 5 parts of calcined calcined calcined shell, 2 parts of zirconium boride, 8 parts of zircon sand, 5 parts of kaolin, and 6 parts of zinc oxide are mixed evenly and then calcined. The calcination process is as follows: the temperature is raised from room temperature to 580°C at a rate of 7°C / min, then raised to 1150°C at a rate of 5°C / min, then raised to 1500°C at a rate of 10°C / min, then cooled to 1410°C at a rate of 14°C / min and held for 35 min, then cooled to 1160°C at a rate of 10°C / min and held for 30 min. The calcined glass melt is then quenched in cold water to obtain the composite zircon white opaque frit. The chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 53.85%, Al2O3 12.25%, CaO 4.82%, MgO 0.85%, K2O 2.11%, Na2O 0.68%, ZrO2 13.79%, P2O5 1.48%, ZnO 5.03%, Fe2O3 0.02%, TiO2 0.04%, and IL 4.49%.

[0084] The preparation method of the ultra-white glaze includes the following steps: 25 parts modified quartz, 35 parts potassium feldspar, 12 parts kaolin, 30 parts composite zirconium white emulsion frit, 2 parts wollastonite, 8 parts alumina, and 8 parts polyacrylamide gel are added to a ball mill. Then, water (40% of the total weight of the above ultra-white glaze raw materials), 0.35% carboxymethyl cellulose, and 0.3% sodium tripolyphosphate are added, and the mixture is ball-milled for 11 hours. The fineness of the glaze slurry after ball milling is 0.3% residue on a 325-mesh sieve, a specific gravity of 1.83 g / ml, and a flow rate of 75 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained. The preparation step of the modified quartz includes: adding 7% titanium dioxide to 93% quartz sand, mixing evenly, and then sintering at a sintering temperature of 1350℃ for 0.6 hours to obtain the modified quartz.

[0085] During the preparation of this ceramic tile, the aforementioned ultra-white glaze is sprayed onto the surface glaze of the ceramic tile. The specific gravity of the ultra-white glaze is adjusted to 1.38 g / ml when applied, and the firing temperature of the ceramic tile is 1200℃.

[0086] The ceramic bricks prepared in Example 9 were subjected to performance testing, and the specific test results are shown in the table below:

[0087]

[0088] As can be seen from the test results in the table above, by compounding the raw materials of composite zirconium white emulsion frit and further optimizing its chemical composition and calcination process, the whiteness of ceramic tiles can reach about 88°, the surface flatness test value can be reduced to 0.52, and the ceramic tiles have good glaze quality.

[0089] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A composite zirconium white emulsion frit, characterized in that, By weight, the raw materials of the composite zircon white emulsion frit include: 25-40 parts quartz, 5-10 parts calcined alumina, 20-35 parts potassium feldspar, 3-10 parts talc, 5-10 parts calcite, 5-10 parts calcium phosphate, 1-5 parts calcined shells, 7-15 parts zirconium boride, 3-10 parts zircon sand, 1-5 parts kaolin, and 3-10 parts zinc oxide. The chemical composition of the composite zirconium white opaque frit, by mass percentage, includes: SiO2 45-60%, Al2O3 10-15%, CaO 5-8%, MgO 0.7-1.8%, K2O 2-4%, Na2O 0.6-1%, ZrO2 7-15%, P2O5 1.4-3%, ZnO 2-9%, Fe2O3 0.01-0.05%, and TiO2 0.01-0.05%. The composite zirconium white opaque frit is prepared by a method including the following steps: the raw materials of the composite zirconium white opaque frit are mixed evenly and then calcined; the calcined glass melt is then quenched in cold water to obtain the composite zirconium white opaque frit. The calcination process is as follows: the temperature is raised from room temperature to 530-600℃ at a rate of 6-8℃ / min, then raised to 1000-1200℃ at a rate of 3-5℃ / min, then raised to 1450-1550℃ at a rate of 9-10℃ / min, then lowered to 1400-1420℃ at a rate of 12-14℃ / min and held for 30-37min, then lowered to 1150-1250℃ at a rate of 5-10℃ / min and held for 25-40min.

2. A super white glaze, characterized in that, The ultra-white glaze, by weight, is prepared from the following raw materials: 10-30 parts modified quartz, 20-40 parts potassium feldspar, 5-15 parts kaolin, 20-40 parts of the composite zircon white opaque frit as described in claim 1, 1-5 parts wollastonite, 5-10 parts alumina, and 5-15 parts polyacrylamide gel.

3. The ultra-white glaze according to claim 2, characterized in that, The preparation steps of the modified quartz include: adding 5-10% titanium dioxide to 90-95% quartz sand by mass percentage, mixing evenly, and then sintering to obtain the modified quartz. The sintering temperature is 1300-1400℃, and the sintering time is 0.5-1h.

4. The ultra-white glaze according to claim 2, characterized in that, The ultra-white glaze is prepared by a method comprising the following steps: adding the raw materials of the ultra-white glaze into a ball mill, then adding 35-40% water, 0.25-0.35% carboxymethyl cellulose and 0.3-0.4% sodium tripolyphosphate by weight of the raw materials of the ultra-white glaze, and ball milling for 10-12 hours. The fineness of the glaze slurry after ball milling is 0.2%-0.4% residue on a 325-mesh sieve, with a specific gravity of 1.80-1.85 g / ml and a flow rate of 60-80 seconds. After removing iron from the glaze slurry, the ultra-white glaze is obtained.

5. A ceramic tile, characterized in that, The ceramic brick is fired at a temperature of 1180-1210°C using the ultra-white glaze as described in any one of claims 2-4.

6. A ceramic tile according to claim 5, characterized in that, The ultra-white glaze is applied to the surface glaze of the ceramic tile, and the specific gravity of the ultra-white glaze is adjusted to 1.35-1.40 g / ml when it is applied.

7. A ceramic tile according to claim 5, characterized in that, The whiteness of the ceramic tile is above 85.

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