High-white ceramic frit and its preparation method

Abstract

This invention belongs to the field of ceramic frit preparation technology, specifically relating to a high-whiteness ceramic frit and its preparation method. The high-whiteness ceramic frit of this invention is composed of the following raw materials: quartz, calcined alumina, lithium kaolin ore, magnesium slag, cordierite powder, lanthanum silicate, strontium tetraborate, sodium fluorosilicate, nano-sodium zirconium phosphate, nano-yttrium aluminate, and nano-samarium oxide. In the high-whiteness ceramic frit of this invention, quartz and calcined alumina form a continuous aluminosilicate glass phase three-dimensional network structure; lithium kaolin ore, magnesium slag, strontium tetraborate, and sodium fluorosilicate work synergistically to fill the pores of the three-dimensional network structure to promote the densification of the ceramic frit and avoid whiteness scattering and mechanical property degradation caused by pores; the introduction of cordierite powder and lanthanum silicate ensures the mechanical properties of the ceramic frit; the addition of nano-sodium zirconium phosphate, nano-yttrium aluminate, and nano-samarium oxide as functional fillers further enhances the whiteness of the ceramic frit.

Description

Technical Field

[0001] This invention belongs to the field of ceramic frit preparation technology, specifically relating to a high-whiteness ceramic frit and its preparation method. Background Technology

[0002] Fused frit is an inorganic glass formed by melting ceramic mineral and chemical raw materials into a glaze melt at high temperature according to a formula, and then rapidly cooling the high-temperature glaze melt using water quenching or water-cooled metal rollers. Fused frit is a complex silicate, and its advantages include: ① It can melt easily soluble and toxic raw materials at high temperatures and combine them with SiO2 or other oxides to form an insoluble or slightly soluble, non-toxic or slightly toxic glass; ② Compared to raw material glazes, volatile carbonates and nitrates in the raw materials can be volatilized during the high-temperature melting process, reducing pinholes in the glaze surface; ③ Fused frit has high internal energy, and compared to raw material glazes of the same composition, fused frit glazes have a lower firing temperature, making them more suitable for the low-temperature, fast-firing production mode of ceramic glazed tiles.

[0003] According to their appearance and uses, frits can be broadly classified into the following categories: glossy transparent frits, glossy opaque frits, matte or calendered frits, flux frits, and colored frits. Among them, glossy opaque frits are the core type for achieving the "high opacity and high whiteness" effect in ceramics. High whiteness frits are a high-end functional sub-category of glossy opaque frits and are one of the key raw materials in the current high-end ceramics field. They are mainly used in high-end daily-use ceramics (such as bone china tableware), sanitary ceramics (such as smart toilet substrates), architectural decorative ceramics (such as ultra-thin high whiteness slabs), and special functional ceramics (such as laboratory corrosion-resistant glassware).

[0004] However, existing high-whiteness ceramic frits lack sufficient whiteness and purity, and are easily affected by trace amounts of Fe in the raw materials. 3+ Problems such as the formation of color centers and light scattering caused by internal pores in the frit lead to a "grayish" or "yellowish" appearance, making it difficult to meet the pure whiteness requirements of high-end ceramics. Furthermore, to ensure the whiteness of the ceramic frit, raw materials often contain components that weaken mechanical properties, resulting in insufficient mechanical properties of the frit. Therefore, it is necessary to explore a novel method for preparing high-whiteness ceramic frits. Summary of the Invention

[0005] The purpose of this invention is to provide a high-whiteness ceramic frit, wherein the ceramic frit has high whiteness. In addition, this invention also provides a method for its preparation.

[0006] The high-whiteness ceramic frit of the present invention is composed of the following raw materials in parts by weight: 46-48 parts quartz, 12-14 parts calcined alumina, 8-10 parts lithium kaolin ore, 4-5 parts magnesium slag, 6-8 parts cordierite powder, 3-4 parts lanthanum silicate, 1.8-2.0 parts strontium tetraborate, 0.9-1.1 parts sodium fluorosilicate, 0.5-0.7 parts nano-sodium zirconium phosphate, 0.3-0.5 parts nano-yttrium aluminate, and 0.1-0.2 parts nano-samarium oxide.

[0007] The lithium kaolin ore, by mass percentage, has the following chemical composition: SiO2 65.45%, Al2O3 19.02%, K2O 5.71%, Na2O 3.30%, CaO 3.44%, MgO 0.12%, Li2O 1.15%, Fe2O3 0.12%, and loss on ignition 1.69%.

[0008] The magnesium slag is a solid waste generated from the magnesium smelting industry. Its chemical composition by mass percentage is as follows: CaO 66.36%, SiO2 22.68%, Al2O3 1.14%, Fe2O3 2.23%, MgO 6.02%, and loss on ignition 1.57%.

[0009] The cordierite powder, by mass percentage, has the following chemical composition: SiO2 49.63%, Al2O3 35.28%, MgO 12.36%, Fe2O3 0.08%, CaO 0.54%, TiO2 0.01%, K2O 0.30%, Na2O 0.12%, and loss on ignition 1.68%.

[0010] The method for preparing the high-whiteness ceramic frit of the present invention comprises the following steps:

[0011] (1) Magnesium slag, cordierite powder and lithium kaolin ore are subjected to wet ball milling, primary iron removal, acid washing, neutralization and secondary iron removal, and then sieved and dried to prepare the first mixture;

[0012] (2) Nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, pre-dispersed in anhydrous ethanol and then calcined, pulverized and coated to prepare a second mixture;

[0013] (3) Mix the first mixture, the second mixture, quartz, calcined alumina, lanthanum silicate, strontium tetraborate and sodium fluorosilicate evenly to prepare the third mixture. Place the third mixture into a high-temperature furnace for sintering. Quench the sintered product to prepare a high-white ceramic frit.

[0014] Among them: in step (1) wet ball milling, the mass ratio of magnesium slag, cordierite powder and lithium kaolin ore, zirconium oxide balls and water is 1:2.0:0.9.

[0015] Step (1) The wet ball milling time is 2-2.2 hours.

[0016] The parameters for primary and secondary iron removal in step (1) are the same, with the magnetic field strength being 1.5T and the flow velocity being 1.1m / s.

[0017] The pickling in step (1) involves adding hydrochloric acid with a mass concentration of 13-15%, the mass of which accounts for 0.8-1.0% of the mass of the slurry obtained after wet ball milling, the pickling temperature being 40-42℃, and the pickling time being 30-33min.

[0018] The neutralization described in step (1) involves adding a 5% ammonia solution after acid washing to adjust the pH of the slurry to 6.7, then adding 0.03% polycarboxylate dispersant by mass of the slurry, and finally rinsing with clean water 2-3 times for secondary iron removal. The polycarboxylate dispersant is the Japanese Sanno Spectro 5040 dispersant sold by Jinan Zhengyin Chemical Co., Ltd.

[0019] After the second iron removal in step (1), the product is passed through a 325-mesh sieve and then spray-dried. The inlet air temperature is 180℃, the outlet air temperature is 85℃, and the residence time is 8-10s.

[0020] In step (2), nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, and 5% anhydrous ethanol is added to disperse the mixture ultrasonically for 10-15 minutes, followed by calcination.

[0021] In step (2), the calcination temperature is 480℃ and the calcination time is 30min.

[0022] In step (2), the material is pulverized to D using an air jet mill. 50 =0.4μm.

[0023] The coating process described in step (2) involves adding a KH550 silane coupling agent-ethanol solution to the obtained nano-mixed powder after air jet milling, stirring at 400 r / min for 20 min at room temperature, and then drying at 60℃ for 1 h to obtain the second mixture. The KH550 silane coupling agent in the KH550 silane coupling agent-ethanol solution accounts for 0.3% of the total mass of the ethanol solution and the KH550 silane coupling agent, and the KH550 silane coupling agent-ethanol solution accounts for 5% of the mass of the nano-mixed powder.

[0024] The mixing time in step (3) is 15-20 min.

[0025] The sintering in step (3) involves heating to 1300-1320℃ at a heating rate of 5-6℃ / min and holding for 35-40min.

[0026] The quenching described in step (3) involves placing the sintered product in cold water at 30°C for 3-5 seconds, dehydrating it using a vibrating screen, and then drying it at 100-105°C for 1 hour to prepare a high-white ceramic frit.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) The high whiteness ceramic frit of the present invention forms a continuous three-dimensional network structure of aluminosilicate glass phase with quartz and calcined alumina; lithium kaolin, magnesium slag, strontium tetraborate and sodium fluorosilicate work together to fill the pores of the three-dimensional network structure to promote the densification of the ceramic frit and avoid whiteness scattering and mechanical property degradation caused by pores; the mechanical properties of the ceramic frit are guaranteed by introducing cordierite powder and lanthanum silicate; and the whiteness of the ceramic frit is further improved by adding nano sodium zirconium phosphate, nano yttrium aluminate and nano samarium oxide as functional fillers.

[0029] (2) In the high-whiteness ceramic frit described in this invention, quartz and calcined alumina melt and depolymerize at high temperature into [SiO4] tetrahedra and [AlO4] tetrahedra, respectively, forming a continuous three-dimensional network structure of aluminosilicate glass phase through oxygen bridges. The synergistic effect among lithium kaolin, magnesium slag, strontium tetraborate, and sodium fluorosilicate promotes the densification of the aluminosilicate glass phase. Among them, the alkali metal ions (Li...) in the lithium kaolin... + K + Na + By inserting into the silicon-oxygen tetrahedral network, the Si-O-Si bonds are broken, reducing the depolymerization activation energy and thus lowering the glass transition temperature. Meanwhile, the alkaline earth metal ions (Ca) in the magnesium slag... 2+ and Mg 2+ Strontium tetraborate forms weak bonds with silicon-oxygen tetrahedra, reducing melt viscosity and promoting the filling of tiny voids between particles, thus reducing the formation of initial porosity. At high temperatures, strontium tetraborate melts and dissociates, releasing B4O7. 2- With Sr 2+ B4O7 2- Further conversion to B2O3 and the formation of boron-oxygen triangular bodies lowers the initial melting temperature and accelerates the melting process. The [BO3] triangular bodies and [SiO4] tetrahedra work synergistically to form a stable viscosity plateau at high temperatures, preventing the melt from becoming too thin. This ensures sufficient reaction time for cross-linking between [SiO4] and [AlO4], and also facilitates melt homogenization and gas removal. Simultaneously, SrO enhances the wettability of the melt to particles such as quartz and alumina, preventing the formation of pores from unmelted particles. Sodium fluorosilicate releases F at high temperatures. -It can directly break silicon-oxygen bonds, accelerate the depolymerization of raw materials such as quartz, further reduce melt viscosity, and make it easier for gases such as CO2 and H2O generated during the melting process to float and escape. At the same time, the gases released by the decomposition of sodium fluorosilicate help to remove bubbles in the melt, promote melt homogenization, and further eliminate porosity. In summary, lithium kaolin ore and magnesium slag jointly regulate melt viscosity and fluidity, strontium tetraborate ensures sufficient reaction and wettability, and sodium fluorosilicate removes bubbles, ultimately enabling the aluminosilicate tetrahedra to fully crosslink, forming a continuous, non-porous, dense glass phase framework, avoiding whiteness scattering (graying, darkening) and mechanical property degradation caused by porosity. In addition, the whiteness of the ceramic frit is further improved by adding nano-sodium zirconium phosphate, nano-yttrium aluminate, and nano-samarium oxide to the raw materials.

[0030] (3) The high-whiteness ceramic frit of the present invention, through the synergistic effect of nano-sodium zirconium phosphate, nano-yttrium aluminate, and nano-samarium oxide in the raw materials, further improves the whiteness of the prepared ceramic frit. Among them, nano-sodium zirconium phosphate has high hardness and is dispersed in the glass phase to form "rigid support points," increasing the hardness of the frit. Simultaneously, its refractive index is similar to but not equal to that of the glass phase. Through the difference in refractive index between the particles and the glass phase, it can produce weak scattering of visible light, resulting in a whitening effect. Furthermore, the ionic crystal structure of nano-sodium zirconium phosphate is stable, which can inhibit the crystallization of the glass phase, thereby avoiding the decrease in whiteness caused by crystallization. Nano-yttrium aluminate, due to the rare earth element Y... 3+ Its large ionic radius allows it to occupy lattice defects in the glass phase and suppress Fe. 3+ The color reaction prevents the fused mass from turning yellow. Furthermore, the perovskite crystal structure of nano-yttrium aluminate has high bond energy, resulting in a tight bond with glass, which helps improve the density and mechanical strength of the ceramic fused mass. The rare earth element Sm in nano-samarium oxide... 3+ By competitively absorbing 280-380nm ultraviolet light through 4f transition, the Fe... 3+ This increases the excitation probability, thereby reducing yellow-brown coloration; simultaneously, its ions occupy vacancies in the high-temperature glass network, increasing cross-linking and suppressing bubble / phase separation generation, resulting in a cleaner base color and purer visual whiteness of the fused mass. Thus, the three fillers interact to further improve the whiteness of the prepared ceramic fused mass.

[0031] (4) The high-whiteness ceramic frit of the present invention ensures the mechanical properties of the prepared ceramic frit by adding cordierite powder and lanthanum silicate. Cordierite powder has a low coefficient of thermal expansion. After being incorporated into the aluminosilicate glass phase, it can help reduce the overall coefficient of thermal expansion of the frit, reduce the internal stress generated during sudden temperature changes, and thus prevent the frit from cracking. At the same time, its high content of Al2O3 provides rigid support for the aluminosilicate skeleton, improves the basic hardness and wear resistance of the frit, and its own MgO and magnesium slag work together to further optimize the melt fluidity and help improve the skeleton density. The La in lanthanum silicate... 3+With its large ionic radius and high charge, lanthanum silicate can occupy the lattice defects of the aluminosilicate framework, preventing the migration of framework ions at high temperatures or crystallization during cooling. At the same time, lanthanum silicate has excellent chemical stability at the sintering temperature and is dispersed in the glass phase framework in the form of tiny particles, forming a "rigid dispersed phase" that concentrates stress and significantly improves mechanical strength.

[0032] (5) The preparation method of the high white ceramic frit of the present invention is simple and the parameters are easy to control, so that the prepared ceramic frit has high whiteness and stable performance. Detailed Implementation

[0033] Example 1

[0034] The high-whiteness ceramic frit described in Example 1 is composed of the following raw materials by weight: 47 parts quartz, 13 parts calcined alumina, 9 parts lithium kaolin ore, 4.5 parts magnesium slag, 7 parts cordierite powder, 3.5 parts lanthanum silicate, 1.9 parts strontium tetraborate, 1.0 part sodium fluorosilicate, 0.6 parts nano-sodium zirconium phosphate, 0.4 parts nano-yttrium aluminate, and 0.15 parts nano-samarium oxide.

[0035] The lithium kaolin ore, by mass percentage, has the following chemical composition: SiO2 65.45%, Al2O3 19.02%, K2O 5.71%, Na2O 3.30%, CaO 3.44%, MgO 0.12%, Li2O 1.15%, Fe2O3 0.12%, and loss on ignition 1.69%.

[0036] The magnesium slag is a solid waste generated from the magnesium smelting industry. Its chemical composition by mass percentage is as follows: CaO 66.36%, SiO2 22.68%, Al2O3 1.14%, Fe2O3 2.23%, MgO 6.02%, and loss on ignition 1.57%.

[0037] The cordierite powder, by mass percentage, has the following chemical composition: SiO2 49.63%, Al2O3 35.28%, MgO 12.36%, Fe2O3 0.08%, CaO 0.54%, TiO2 0.01%, K2O 0.30%, Na2O 0.12%, and loss on ignition 1.68%.

[0038] The preparation method of the high-whiteness ceramic frit described in Example 1 consists of the following steps:

[0039] (1) Magnesium slag, cordierite powder and lithium kaolin ore are subjected to wet ball milling, primary iron removal, acid washing, neutralization and secondary iron removal, and then sieved and dried to prepare the first mixture;

[0040] (2) Nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, pre-dispersed in anhydrous ethanol and then calcined and pulverized to prepare a second mixture;

[0041] (3) Mix the first mixture, the second mixture, quartz, calcined alumina, lanthanum silicate, strontium tetraborate and sodium fluorosilicate evenly to prepare the third mixture. Place the third mixture into a high-temperature furnace for sintering. Quench the sintered product to prepare a high-white ceramic frit.

[0042] Among them: in step (1) wet ball milling, the mass ratio of magnesium slag, cordierite powder and lithium kaolin ore, zirconium oxide balls and water is 1:2.0:0.9.

[0043] The wet ball milling time for step (1) is 2.1 hours.

[0044] The parameters for primary and secondary iron removal in step (1) are the same, with the magnetic field strength being 1.5T and the flow velocity being 1.1m / s.

[0045] The pickling in step (1) involves adding hydrochloric acid with a mass concentration of 14%, the mass of which accounts for 0.9% of the mass of the slurry obtained after wet ball milling, the pickling temperature is 41℃, and the pickling time is 31min.

[0046] The neutralization described in step (1) is to add a 5% ammonia solution after pickling to adjust the pH of the slurry to 6.7, then add 0.03% polycarboxylate dispersant by mass of the slurry, and finally rinse with clean water three times for secondary iron removal; the polycarboxylate dispersant is the Japanese Sanno Spectro 5040 dispersant sold by Jinan Zhengyin Chemical Co., Ltd.

[0047] After the second iron removal in step (1), the product is passed through a 325-mesh sieve and then spray-dried. The inlet air temperature is 180℃, the outlet air temperature is 85℃, and the residence time is 9s.

[0048] In step (2), nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, and 5% anhydrous ethanol is added to disperse the mixture ultrasonically for 13 minutes, followed by calcination.

[0049] In step (2), the calcination temperature is 480℃ and the calcination time is 30min.

[0050] In step (2), the material is pulverized to D using an air jet mill. 50 =0.4μm.

[0051] The coating process described in step (2) involves adding a KH550 silane coupling agent-ethanol solution to the obtained nano-mixed powder after air jet milling, stirring at 400 r / min for 20 min at room temperature, and then drying at 60℃ for 1 h to obtain the second mixture. The KH550 silane coupling agent in the KH550 silane coupling agent-ethanol solution accounts for 0.3% of the total mass of the ethanol solution and the KH550 silane coupling agent, and the KH550 silane coupling agent-ethanol solution accounts for 5% of the mass of the nano-mixed powder.

[0052] The mixing time in step (3) is 17 min.

[0053] The sintering in step (3) involves heating to 1310℃ at a heating rate of 5.5℃ / min and holding for 38 minutes.

[0054] The quenching described in step (3) involves placing the sintered product in cold water at 30°C for 4 seconds, dehydrating it using a vibrating screen, and then drying it at 103°C for 1 hour to prepare a high-white ceramic frit.

[0055] The whiteness of the high-white ceramic frit prepared in Example 1 was 92, and the elastic modulus was 89 GPa.

[0056] Example 2

[0057] The high-whiteness ceramic frit described in Example 2 is composed of the following raw materials by weight: 46 parts quartz, 14 parts calcined alumina, 8 parts lithium kaolin ore, 4 parts magnesium slag, 6 parts cordierite powder, 4 parts lanthanum silicate, 1.8 parts strontium tetraborate, 1.1 parts sodium fluorosilicate, 0.5 parts nano-sodium zirconium phosphate, 0.5 parts nano-yttrium aluminate, and 0.2 parts nano-samarium oxide.

[0058] The lithium kaolin ore, by mass percentage, has the following chemical composition: SiO2 65.45%, Al2O3 19.02%, K2O 5.71%, Na2O 3.30%, CaO 3.44%, MgO 0.12%, Li2O 1.15%, Fe2O3 0.12%, and loss on ignition 1.69%.

[0059] The magnesium slag is a solid waste generated from the magnesium smelting industry. Its chemical composition by mass percentage is as follows: CaO 66.36%, SiO2 22.68%, Al2O3 1.14%, Fe2O3 2.23%, MgO 6.02%, and loss on ignition 1.57%.

[0060] The cordierite powder, by mass percentage, has the following chemical composition: SiO2 49.63%, Al2O3 35.28%, MgO 12.36%, Fe2O3 0.08%, CaO 0.54%, TiO2 0.01%, K2O 0.30%, Na2O 0.12%, and loss on ignition 1.68%.

[0061] The preparation method of the high-whiteness ceramic frit described in Example 2 consists of the following steps:

[0062] (1) Magnesium slag, cordierite powder and lithium kaolin ore are subjected to wet ball milling, primary iron removal, acid washing, neutralization and secondary iron removal, and then sieved and dried to prepare the first mixture;

[0063] (2) Nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, pre-dispersed in anhydrous ethanol and then calcined and pulverized to prepare a second mixture;

[0064] (3) Mix the first mixture, the second mixture, quartz, calcined alumina, lanthanum silicate, strontium tetraborate and sodium fluorosilicate evenly to prepare the third mixture. Place the third mixture into a high-temperature furnace for sintering. Quench the sintered product to prepare a high-white ceramic frit.

[0065] Among them: in step (1) wet ball milling, the mass ratio of magnesium slag, cordierite powder and lithium kaolin ore, zirconium oxide balls and water is 1:2.0:0.9.

[0066] Step (1) The wet ball milling time is 2 hours.

[0067] The parameters for primary and secondary iron removal in step (1) are the same, with the magnetic field strength being 1.5T and the flow velocity being 1.1m / s.

[0068] The pickling in step (1) involves adding hydrochloric acid with a mass concentration of 13%, the mass of which accounts for 0.8% of the mass of the slurry obtained after wet ball milling, the pickling temperature is 40℃, and the pickling time is 30min.

[0069] The neutralization described in step (1) is to add a 5% ammonia solution after pickling to adjust the pH of the slurry to 6.7, then add 0.03% polycarboxylate dispersant by mass of the slurry, and finally rinse twice with clean water for secondary iron removal; the polycarboxylate dispersant is the Japanese Sanno Spectro 5040 dispersant sold by Jinan Zhengyin Chemical Co., Ltd.

[0070] After the second iron removal in step (1), the sample is passed through a 325-mesh sieve and then spray-dried. The inlet air temperature is 180℃, the outlet air temperature is 85℃, and the residence time is 8s.

[0071] In step (2), nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, and 5% anhydrous ethanol is added to disperse the mixture ultrasonically for 15 minutes, followed by calcination.

[0072] In step (2), the calcination temperature is 480℃ and the calcination time is 30min.

[0073] In step (2), the material is pulverized to D using an air jet mill. 50 =0.4μm.

[0074] The coating process described in step (2) involves adding a KH550 silane coupling agent-ethanol solution to the obtained nano-mixed powder after air jet milling, stirring at 400 r / min for 20 min at room temperature, and then drying at 60℃ for 1 h to obtain the second mixture. The KH550 silane coupling agent in the KH550 silane coupling agent-ethanol solution accounts for 0.3% of the total mass of the ethanol solution and the KH550 silane coupling agent, and the KH550 silane coupling agent-ethanol solution accounts for 5% of the mass of the nano-mixed powder.

[0075] The mixing time in step (3) is 15 min.

[0076] The sintering in step (3) involves heating to 1300℃ at a heating rate of 5℃ / min and holding for 40min.

[0077] The quenching described in step (3) involves placing the sintered product in cold water at 30°C for 3 seconds, dehydrating it using a vibrating screen, and then drying it at 100°C for 1 hour to prepare a high-white ceramic frit.

[0078] The whiteness of the high-white ceramic frit prepared in Example 2 was 91, and the elastic modulus was 87 GPa.

[0079] Example 3

[0080] The high-whiteness ceramic frit described in Example 3 is composed of the following raw materials by weight: 48 parts quartz, 12 parts calcined alumina, 10 parts lithium kaolin ore, 5 parts magnesium slag, 8 parts cordierite powder, 3 parts lanthanum silicate, 2.0 parts strontium tetraborate, 0.9 parts sodium fluorosilicate, 0.7 parts nano-sodium zirconium phosphate, 0.3 parts nano-yttrium aluminate, and 0.1 parts nano-samarium oxide.

[0081] The lithium kaolin ore, by mass percentage, has the following chemical composition: SiO2 65.45%, Al2O3 19.02%, K2O 5.71%, Na2O 3.30%, CaO 3.44%, MgO 0.12%, Li2O 1.15%, Fe2O3 0.12%, and loss on ignition 1.69%.

[0082] The magnesium slag is a solid waste generated from the magnesium smelting industry. Its chemical composition by mass percentage is as follows: CaO 66.36%, SiO2 22.68%, Al2O3 1.14%, Fe2O3 2.23%, MgO 6.02%, and loss on ignition 1.57%.

[0083] The cordierite powder, by mass percentage, has the following chemical composition: SiO2 49.63%, Al2O3 35.28%, MgO 12.36%, Fe2O3 0.08%, CaO 0.54%, TiO2 0.01%, K2O 0.30%, Na2O 0.12%, and loss on ignition 1.68%.

[0084] The preparation method of the high-whiteness ceramic frit described in Example 3 consists of the following steps:

[0085] (1) Magnesium slag, cordierite powder and lithium kaolin ore are subjected to wet ball milling, primary iron removal, acid washing, neutralization and secondary iron removal, and then sieved and dried to prepare the first mixture;

[0086] (2) Nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, pre-dispersed in anhydrous ethanol and then calcined and pulverized to prepare a second mixture;

[0087] (3) Mix the first mixture, the second mixture, quartz, calcined alumina, lanthanum silicate, strontium tetraborate and sodium fluorosilicate evenly to prepare the third mixture. Place the third mixture into a high-temperature furnace for sintering. Quench the sintered product to prepare a high-white ceramic frit.

[0088] Among them: in step (1) wet ball milling, the mass ratio of magnesium slag, cordierite powder and lithium kaolin ore, zirconium oxide balls and water is 1:2.0:0.9.

[0089] Step (1) The wet ball milling time is 2.2 hours.

[0090] The parameters for primary and secondary iron removal in step (1) are the same, with the magnetic field strength being 1.5T and the flow velocity being 1.1m / s.

[0091] The pickling in step (1) involves adding hydrochloric acid with a mass concentration of 15%, the mass of which accounts for 1.0% of the mass of the slurry obtained after wet ball milling, the pickling temperature is 42℃, and the pickling time is 33min.

[0092] The neutralization described in step (1) is to add a 5% ammonia solution after pickling to adjust the pH of the slurry to 6.7, then add 0.03% polycarboxylate dispersant by mass of the slurry, and finally rinse with clean water three times for secondary iron removal; the polycarboxylate dispersant is the Japanese Sanno Spectro 5040 dispersant sold by Jinan Zhengyin Chemical Co., Ltd.

[0093] After the second iron removal in step (1), the product is passed through a 325-mesh sieve and then spray-dried. The inlet air temperature is 180℃, the outlet air temperature is 85℃, and the residence time is 10s.

[0094] In step (2), nano-sodium zirconium phosphate, nano-yttrium aluminate and nano-samarium oxide are mixed evenly, and 5% anhydrous ethanol is added to disperse the mixture ultrasonically for 10 min, followed by calcination.

[0095] In step (2), the calcination temperature is 480℃ and the calcination time is 30min.

[0096] In step (2), the material is pulverized to D using an air jet mill. 50 =0.4μm.

[0097] The coating process described in step (2) involves adding a KH550 silane coupling agent-ethanol solution to the obtained nano-mixed powder after air jet milling, stirring at 400 r / min for 20 min at room temperature, and then drying at 60℃ for 1 h to obtain the second mixture. The KH550 silane coupling agent in the KH550 silane coupling agent-ethanol solution accounts for 0.3% of the total mass of the ethanol solution and the KH550 silane coupling agent, and the KH550 silane coupling agent-ethanol solution accounts for 5% of the mass of the nano-mixed powder.

[0098] The mixing time in step (3) is 20 min.

[0099] The sintering in step (3) involves heating to 1320℃ at a heating rate of 6℃ / min and holding at that temperature for 35min.

[0100] The quenching described in step (3) involves placing the sintered product in cold water at 30°C for 5 seconds, dehydrating it using a vibrating screen, and then drying it at 105°C for 1 hour to prepare a high-white ceramic frit.

[0101] The whiteness of the high-white ceramic frit prepared in Example 3 was 93 and the elastic modulus was 91 GPa.

[0102] Comparative Example 1

[0103] The preparation method of the high-whiteness ceramic frit described in Comparative Example 1 is the same as that in Example 1, except that the raw material composition is different. The high-whiteness ceramic frit described in Comparative Example 1 is composed of the following raw materials in parts by weight: 47 parts quartz, 13 parts calcined alumina, 9 parts lithium kaolin ore, 4.5 parts magnesium slag, 7 parts cordierite powder, 3.5 parts lanthanum silicate, 1.9 parts strontium tetraborate, 1.0 part sodium fluorosilicate, 0.4 parts nano-yttrium aluminate, and 0.15 parts nano-samarium oxide.

[0104] The whiteness of the high-white ceramic frit prepared in Comparative Example 1 was 85, and the elastic modulus was 81 GPa.

[0105] Comparative Example 2

[0106] The preparation method of the high-whiteness ceramic frit described in Comparative Example 2 is the same as that in Example 1, except that the raw material composition is different. The high-whiteness ceramic frit described in Comparative Example 2, by weight, is composed of the following raw materials: 47 parts quartz, 13 parts calcined alumina, 9 parts lithium kaolin ore, 4.5 parts magnesium slag, 7 parts cordierite powder, 3.5 parts lanthanum silicate, 1.9 parts strontium tetraborate, 1.0 part sodium fluorosilicate, 0.6 parts nano-sodium zirconium phosphate, and 0.15 parts nano-samarium oxide.

[0107] The whiteness of the high-white ceramic frit prepared in Comparative Example 2 was 87, and the elastic modulus was 83 GPa.

[0108] Comparative Example 3

[0109] The preparation method of the high-whiteness ceramic frit described in Comparative Example 3 is the same as that in Example 1, except that the raw material composition is different. The high-whiteness ceramic frit described in Comparative Example 3, by weight, is composed of the following raw materials: 47 parts quartz, 13 parts calcined alumina, 9 parts lithium kaolin ore, 4.5 parts magnesium slag, 7 parts cordierite powder, 3.5 parts lanthanum silicate, 1.9 parts strontium tetraborate, 1.0 part sodium fluorosilicate, 0.6 parts nano-sodium zirconium phosphate, and 0.4 parts nano-yttrium aluminate.

[0110] The whiteness of the high-white ceramic frit prepared in Comparative Example 3 was 88, and the elastic modulus was 84 GPa.

Claims

1. A high-white ceramic frit, characterized by: The raw materials are composed of, in parts by weight, quartz 46-48 parts, calcined alumina 12-14 parts, lithium china clay 8-10 parts, magnesium slag 4-5 parts, cordierite powder 6-8 parts, lanthanum silicate 3-4 parts, strontium tetraborate 1.8-2.0 parts, sodium fluorosilicate 0.9-1.1 parts, nano zirconium phosphate sodium 0.5-0.7 parts, nano yttrium aluminate 0.3-0.5 parts, and nano samarium oxide 0.1-0.2 parts.

2. The high-white ceramic frit according to claim 1, wherein: The lithium china clay has the following chemical composition in mass percentage: SiO2 65.45%, Al2O3 19.02%, K2O 5.71%, Na2O 3.30%, CaO 3.44%, MgO 0.12%, Li2O 1.15%, Fe2O3 0.12%, and loss on ignition 1.69%.

3. The high-white ceramic frit of claim 1, wherein: The magnesium slag has the following chemical composition in mass percentage: CaO 66.36%, SiO2 22.68%, Al2O3 1.14%, Fe2O3 2.23%, MgO 6.02%, and loss on ignition 1.57%.

4. The high-white ceramic frit of claim 1, wherein: The cordierite powder has the following chemical composition in mass percentage: SiO2 49.63%, Al2O3 35.28%, MgO 12.36%, Fe2O3 0.08%, CaO 0.54%, TiO2 0.01%, K2O 0.30%, Na2O 0.12%, and loss on ignition 1.68%.

5. A method of producing the high-white ceramic frit of claim 1, characterized by: The method comprises the following steps: (1) wet ball milling, primary iron removal, acid washing, neutralization, secondary iron removal, sieving, and drying of the magnesium slag, cordierite powder, and lithium china clay to obtain a first mixture; (2) mixing, pre-dispersing in anhydrous ethanol, calcining, crushing, and coating of the nano zirconium phosphate sodium, nano yttrium aluminate, and nano samarium oxide to obtain a second mixture; (3) mixing the first mixture, the second mixture, quartz, calcined alumina, lanthanum silicate, strontium tetraborate, and sodium fluorosilicate to obtain a third mixture, sintering the third mixture in a high-temperature furnace, and quenching the sintered product to obtain a high-white ceramic frit.

6. The method of producing high-white ceramic frit according to claim 5, characterized in that: In step (1), the mass ratio of the magnesium slag, cordierite powder, and lithium china clay to zirconia balls and water is 1:2.0:0.

9. The wet ball milling time in step (1) is 2-2.2 h. The parameters for the primary and secondary iron removal in step (1) are the same, and the magnetic field strength is 1.5 T and the flow rate is 1.1 m / s.

7. The method of claim 5, wherein the high-white ceramic frit is prepared by the steps of: In step (1), the acid washing is performed by adding hydrochloric acid with a mass concentration of 13-15%, and the mass of the added hydrochloric acid accounts for 0.8-1.0% of the mass of the slurry obtained after wet ball milling, the acid washing temperature is 40-42℃, and the acid washing time is 30-33 min. ​ In step (1), the neutralization is performed by adding an ammonia water solution with a mass concentration of 5% after the acid washing is completed, adjusting the pH value of the slurry to 6.7, then adding 0.03% of a polycarboxylic acid dispersant based on the mass of the slurry, and finally rinsing 2-3 times with clean water before the secondary iron removal. The secondary iron removal in step (1) is followed by spray drying, with an inlet temperature of 180℃, an outlet temperature of 85℃, and a residence time of 8-10s.

8. The method of producing high-white ceramic frit according to claim 5, characterized by: In step (2), the nano zirconium phosphate sodium, nano yttrium aluminate and nano samarium oxide are mixed uniformly, 5% anhydrous ethanol based on the total mass of the three is added and ultrasonic dispersed for 10-15min, and then calcined; The calcination temperature in step (2) is 480℃, and the calcination time is 30min; Step (2) was ground by jet mill to D 50 = 0.4 μm; In step (2), the coating treatment is as follows: after airflow milling, KH550 silane coupling agent-ethanol solution is added to the obtained nano mixed powder, stirred at room temperature at a speed of 400r / min for 20min, and then placed in a 60℃ air-drying oven for 1h to prepare a second mixture.

9. The method of claim 8, wherein the high-white ceramic frit is prepared by the steps of: In the coating process, the mass of KH550 silane coupling agent in the KH550 silane coupling agent-ethanol solution accounts for 0.3% of the total mass of ethanol solution and KH550 silane coupling agent, and the mass of KH550 silane coupling agent-ethanol solution accounts for 5% of the mass of nano mixed powder. ​ 10. The method of claim 5, wherein the high-white ceramic frit is prepared by the steps of: The mixing time in step (3) is 15-20min; ​ In step (3), the sintering is carried out by increasing the temperature to 1300-1320℃ at a rate of 5-6℃ / min and maintaining the temperature for 35-40min; In step (3), the quenching is carried out by placing the sintered product in 30℃ cold water for 3-5s, dehydrating with a vibrating screen, and then drying at 100-105℃ for 1h to prepare a high-white ceramic melt.