A mixed firing process for glazed tiles with multiple glazing effects

Abstract

The application discloses a technical field of building ceramics, and particularly relates to a mixed firing process of glazed tiles with multiple glaze effects, which comprises the following steps: A, preparing multiple glaze bodies, wherein the glaze bodies comprise at least one of satin glaze glaze bodies, full polishing glaze glaze bodies and high-transparency polishing glaze glaze bodies; B, sequentially conveying the multiple glaze bodies to the brick feeding position of the large-capacity kiln, and firing under the condition that the firing temperature is less than or equal to 1100 DEG C and the firing period is less than or equal to 30 min. The satin glaze glaze body comprises a body layer, low-swelling glaze, color ink and satin glaze; the full polishing glaze glaze body comprises a body layer, medium-swelling glaze, color ink and full polishing glaze; and the high-transparency polishing glaze glaze body comprises a body layer, high-swelling glaze, color ink and high-transparency polishing glaze. The mixed firing process of glazed tiles can realize low-temperature and fast firing of satin glaze ceramic tiles, full polishing glaze ceramic tiles and high-transparency polishing glaze ceramic tiles in the same kiln, and the products after firing can not only meet the physical and chemical properties of the corresponding effect glaze, but also balance the product brick shape.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of architectural ceramics, and in particular to a mixed firing process for glazed tiles with multiple glazing effects. BACKGROUND

[0002] In order to reduce unit cost and improve market competitiveness through economies of scale, and to adapt to the production needs of the industry, existing architectural ceramic production enterprises generally have large-capacity production lines with a daily capacity of up to 40,000 m 2 The core equipment of a large-capacity production line is a super-wide body kiln (hereinafter referred to as a "large-capacity kiln"), which usually has three brick entry positions corresponding to three glazing lines to improve production efficiency and output.

[0003] Generally, a large-capacity kiln can only fire one type of ceramic tile at the same time, but as market competition intensifies, large orders for single product categories are becoming less common, and small orders for products are becoming more common. There are differences in the requirements of small order products, such as body whiteness, body water absorption, body powder granulation process, size, thickness, glazing effect, and product pattern depth.

[0004] Currently, large-capacity kilns cannot adapt to the production of small order products, resulting in the shutdown of many large-capacity kiln production lines. The main reasons are as follows:

[0005] First, the number of small order products is small, resulting in frequent production changes in large-capacity kilns, which leads to high production losses and easily causes kiln downtime, affecting the stability of the firing curve in the kiln and thus affecting product quality.

[0006] Second, the process of different products differs greatly, making it difficult for the kiln to match multiple products, which also affects product quality.

[0007] Therefore, how to achieve mixed firing of multiple ceramic tile products in a large-capacity kiln is a difficult problem in the current market situation for the architectural ceramics industry.

[0008] Satin glaze (glossiness 10-18°), full polishing glaze (glossiness 30-50°) and high-transparency polishing glaze (glossiness 80-100°) are three kinds of effect glazes on the market. The influence of satin glaze, full polishing glaze and high-transparency polishing glaze on the deformation of ceramic tile products is completely different in terms of the formula system of effect glaze. In the past, during the non-mixed firing period, the kiln was adjusted to the formula / technology, that is, the kiln (such as kiln surface temperature, kiln bottom temperature, firing curve and other parameters) was adjusted to compensate for the influence of glaze on the overall deformation of the product. However, in the mixed firing process of multiple ceramic tile products, if the kiln is adjusted to accommodate the deformation of one product category, the remaining product categories will inevitably be affected by the kiln and will deform or even have other defects, thereby reducing the production quality of the remaining product categories. SUMMARY

[0009] The purpose of the present application is to provide a multi-effect glazed tile mixed firing process, which can realize low-temperature fast firing of satin glaze ceramic tiles, full polishing glaze ceramic tiles and high-transparency polishing glaze ceramic tiles in the same kiln, and the fired ceramic tile products not only meet the physical and chemical properties of the corresponding effect glaze, but also balance the tile shapes of the three kinds of ceramic tile products, overcoming the shortcomings of the prior art.

[0010] To achieve this purpose, the present application adopts the following technical solutions:

[0011] A multi-effect glazed tile mixed firing process is suitable for a large-capacity kiln, and the large-capacity kiln is provided with three brick feeding positions in the width direction. The mixed firing process comprises the following steps:

[0012] A. Prepare multiple glaze bodies, and the glaze bodies include at least one of satin glaze glaze bodies, full polishing glaze glaze bodies and high-transparency polishing glaze glaze bodies;

[0013] B. The multiple glaze bodies are sequentially fed to the brick feeding positions of the large-capacity kiln and fired under the condition of firing temperature ≤1100℃ and firing period ≤30min;

[0014] In step A, the satin glaze glaze body includes a body layer, and a low-swelling glaze, color ink and satin glaze are sequentially applied from bottom to top on the top surface of the body layer; the full polishing glaze glaze body includes a body layer, and a medium-swelling glaze, color ink and full polishing glaze are sequentially applied from bottom to top on the top surface of the body layer; and the high-transparency polishing glaze glaze body includes a body layer, and a high-swelling glaze, color ink and high-transparency polishing glaze are sequentially applied from bottom to top on the top surface of the body layer;

[0015] In step B, the firing curve of the large-capacity kiln includes a preheating section, a preheating section, a medium temperature section, a high temperature section, a rapid cooling section and a slow cooling section: the surface temperature of the preheating section rises from room temperature to 950℃, the bottom temperature rises from room temperature to 1100℃, and the time consumption is 3.5-3.7min; the surface temperature of the preheating section rises from 950℃ to 1110℃, the bottom temperature drops from 1100℃ to 1060℃, and the time consumption is 2-2.2min; the surface temperature of the medium temperature section rises from 1110℃ to 1203℃, the bottom temperature rises from 1060℃ to 1226℃, and the time consumption is 7.7-7.9min; the surface temperature of the high temperature section is 1203℃, the bottom temperature is 1226℃, and the time consumption is 4.3-4.5min; the surface temperature of the rapid cooling section drops from 1203℃ to 570℃, the bottom temperature drops from 1226℃ to 300℃, and the time consumption is 4.7-4.9min; the surface temperature of the slow cooling section drops from 570℃ to room temperature, the bottom temperature drops from 300℃ to room temperature, and the time consumption is 6.4-6.6min.

[0016] Preferably, the raw materials of the satin glaze are composed of potassium feldspar, sodium feldspar, kaolin, burned soil, dolomite, calcite, alumina, barium carbonate, zinc oxide and calcium-magnesium clinker, and the addition amount of alumina is ≤1.5% by mass percentage; the silica-alumina ratio of the satin glaze is 2.6-2.8, and the content of Al2O3 in the satin glaze is 17.3-18.3% by mass percentage, the content of BaO is 2.9-3.3% by mass percentage, and the content of ZnO is 2.3-2.6% by mass percentage;

[0017] The raw materials of the full polishing glaze are composed of sodium feldspar, kaolin, burned soil, dolomite, quartz, calcite, alumina, zinc oxide and strontium carbonate; the silica-alumina ratio of the full polishing glaze is 3.0-3.2, and the content of Na2O in the full polishing glaze is 4.2-5.2% by mass percentage, and the content of SrO is 3.3-4.3% by mass percentage;

[0018] The raw materials of the high-transparency polishing glaze are composed of potassium feldspar, calcite, kaolin, wollastonite, burned talc, quartz, barium carbonate, barium sulfate, zinc oxide and calcium-potassium-zinc clinker, and the addition amount of quartz in the high-transparency polishing glaze is ≤8% by mass percentage; the chemical components of the high-transparency polishing glaze include Al2O3, CaO, BaO, ZnO and MgO, and the content of Al2O3 in the high-transparency polishing glaze is 6.7-7.7% by mass percentage, the content of CaO is 14.5-15.5, the content of BaO is 9.0-11.0% by mass percentage, the content of ZnO is 7.0-11.0% by mass percentage, and the content of MgO is ≤1.6% by mass percentage.

[0019] Preferably, the chemical composition of the satin luster glaze includes, in terms of mass percentage, SiO246.8-51.3%, Al2O317.3-18.3%, Fe2O30.15-0.25%, TiO20.1-0.2%, CaO 7.4-8.6%, MgO 2.4-3.4%, K2O 4.0-4.6%, Na2O 1.8-2.4%, BaO 2.9-3.3%, ZnO 2.3-2.6%, and loss on ignition 6.5-9.6%;

[0020] The chemical composition of the full polishing glaze includes, in terms of mass percentage, SiO245.0-49.0%, Al2O314.7-15.6%, Fe2O30.1-0.2%, TiO20.05-0.1%, CaO 8.5-9.5%, MgO 2.5-3.5%, K2O 0.1-0.3%, Na2O 4.2-5.2%, ZnO 3.4-4.4%, SrO 3.3-4.3%, and loss on ignition 8.0-12.0%;

[0021] The chemical composition of the high-transparency polishing glaze includes, in terms of mass percentage, SiO243.5-45.5%, Al2O36.7-7.7%, Fe2O30.1-0.2%, TiO20.04-0.06%, CaO 14.5-15.5%, MgO 1.2-1.6%, K2O 3.1-4.1%, Na2O 0.4-0.9%, BaO 9.0-11.0%, ZnO 7.0-11.0%, and loss on ignition 7.5-8.5%.

[0022] Preferably, the water absorption of the body layer of the satin luster glaze, the full polishing glaze, and the high-transparency polishing glaze is ≤0.5% after the firing of step B;

[0023] The body layer of the satin luster glaze, the full polishing glaze, and the high-transparency polishing glaze are all pressed from low-hygroscopic powder, and the low-hygroscopic powder is prepared by a wet powder preparation process;

[0024] The chemical composition of the low-hygroscopic powder includes Al2O3, CaO, MgO, K2O, and Na2O, and in terms of mass percentage, the content of Al2O3 in the low-hygroscopic powder is 17.2-18.2%, the total content of CaO, MgO, K2O, and Na2O is 5.6-6.6%, the content of CaO is ≥0.8%, the content of MgO is ≥1.8%, the content of K2O is ≥1.5%, and the content of Na2O is ≥1.5%.

[0025] Preferably, the low hygroscopic powder has a chemical composition including, in percentage by mass, SiO2 66.4-67.5%, Al2O3 17.2-18.2%, Fe2O3 1.6-2.7%, TiO2 0.3-0.5%, CaO 0.8-1.2%, MgO 1.8-2.3%, K2O 1.5-1.6%, Na2O 1.5-1.8%, and loss on ignition 4.8-5.5%.

[0026] Preferably, the body layers of the satin glaze, the full polishing glaze, and the high-transparency polishing glaze each have a size of 800 mm x 800 mm, and in the large-capacity kiln, the front side edges of all the body layers along the conveying direction form an included angle one with the width direction of the large-capacity kiln, and the included angle one has an angle of 5-11°.

[0027] Preferably, the body layers of the satin glaze, the full polishing glaze, and the high-transparency polishing glaze each have a size of 750 mm x 1500 mm, and in the large-capacity kiln, the short side edges of all the body layers form an included angle two with the width direction of the large-capacity kiln, and the included angle two has an angle of 7-13°.

[0028] Preferably, the low-expansion glaze has a coefficient of expansion of (6.6-6.8) x 10 -6 / ℃, and the raw materials of the low-expansion glaze include sodium feldspar 36-40 parts, kaolin 9-11 parts, quartz 2-4 parts, nepheline 7-9 parts, alumina 10-14 parts, potassium feldspar 10-14 parts, calcined clay 14-16 parts, calcined talc 1-3 parts, and zirconium silicate 10-14 parts.

[0029] Preferably, the medium-expansion glaze has a coefficient of expansion of (7.3-7.5) x 10 -6 / ℃, and the raw materials of the medium-expansion glaze include sodium feldspar 38-42 parts, kaolin 9-11 parts, quartz 4-6 parts, nepheline 9-11 parts, alumina 12-16 parts, potassium feldspar 10-14 parts, calcined clay 5-7 parts, calcined talc 2-4 parts, and zirconium silicate 10-14 parts.

[0030] Preferably, the high-expansion glaze has a coefficient of expansion of (7.9-8.1) x 10 -6 / ℃, and the raw materials of the high-expansion glaze include sodium feldspar 36-40 parts, kaolin 9-11 parts, quartz 19-22 parts, nepheline 14-16 parts, alumina 14-16 parts, calcined talc 1-3 parts, and zirconium silicate 10-14 parts.

[0031] Preferably, the low-expansion glaze, the satin glaze, the medium-expansion glaze, the full polishing glaze, the high-expansion glaze, and the high-transparency polishing glaze each have an application amount of 420-480 g / m2 .

[0032] Preferably, the inkjet amount of the color ink of the satin luster glaze, the color ink of the full polishing glaze and the color ink of the high-transparency polishing glaze is 4.8-9.6g / m 2 .

[0033] The technical solution provided by the present application can include the following beneficial effects:

[0034] The glaze brick mixed firing process of the present application can realize low-temperature fast firing of satin luster glaze, full polishing glaze and high-transparency polishing glaze in the same kiln, and the fired glaze products not only meet the physical and chemical properties of the corresponding effect glaze, but also balance the shapes of the three types of glaze products, overcoming the shortcomings of the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a layout diagram of 800 specification glaze in the glaze brick mixed firing process of the present application.

[0036] Figure 2 is a layout diagram of 715 specification glaze in the glaze brick mixed firing process of the present application. DETAILED DESCRIPTION

[0037] The technical solution provides a glaze brick mixed firing process of multiple glaze effects, which is suitable for large-capacity kilns, and the large-capacity kiln is provided with three brick feeding positions in the width direction, and the mixed firing process comprises the following steps:

[0038] A, preparing a plurality of glaze, and the glaze includes at least one of satin luster glaze, full polishing glaze and high-transparency polishing glaze;

[0039] B, the plurality of glaze is sequentially conveyed to the brick feeding position of the large-capacity kiln, and is fired under the condition that the firing temperature is less than or equal to 1100 DEG C and the firing period is less than or equal to 30 minutes;

[0040] In step A, the satin luster glaze includes a body layer, and a low-swelling glaze, a color ink and a satin luster glaze are sequentially applied from bottom to top on the top surface of the body layer; the full polishing glaze includes a body layer, and a medium-swelling glaze, a color ink and a full polishing glaze are sequentially applied from bottom to top on the top surface of the body layer; the high-transparency polishing glaze includes a body layer, and a high-swelling glaze, a color ink and a high-transparency polishing glaze are sequentially applied from bottom to top on the top surface of the body layer;

[0041] In step B, the firing curve of the large-capacity kiln comprises a preheating section, a preheating section, a medium temperature section, a high temperature section, a rapid cooling section and a slow cooling section: the surface temperature of the preheating section rises from room temperature to 950℃, the bottom temperature rises from room temperature to 1100℃, and the time consumption is 3.5-3.7min; the surface temperature of the preheating section rises from 950℃ to 1110℃, the bottom temperature drops from 1100℃ to 1060℃, and the time consumption is 2-2.2min; the surface temperature of the medium temperature section rises from 1110℃ to 1203℃, the bottom temperature rises from 1060℃ to 1226℃, and the time consumption is 7.7-7.9min; the surface temperature of the high temperature section is 1203℃, the bottom temperature is 1226℃, and the time consumption is 4.3-4.5min; the surface temperature of the rapid cooling section drops from 1203℃ to 570℃, the bottom temperature drops from 1226℃ to 300℃, and the time consumption is 4.7-4.9min; the surface temperature of the slow cooling section drops from 570℃ to room temperature, the bottom temperature drops from 300℃ to room temperature, and the time consumption is 6.4-6.6min.

[0042] In order to realize the mixed firing of satin glaze ceramic tiles, full polishing glaze ceramic tiles and high transmittance polishing glaze ceramic tiles in the same kiln, the technical scheme puts forward a mixed firing process of glaze tiles with multiple glaze effects. On the one hand, it realizes low temperature fast firing (the firing temperature of the present scheme is ≤1100℃, and the firing period is ≤30min), which is beneficial to reduce energy consumption and carbon emission; on the other hand, it can balance the tile shape of the three kinds of ceramic tile products under the premise of ensuring the realization of the physical and chemical properties of each effect glaze (i.e. satin glaze, full polishing glaze and high transmittance polishing glaze). It should be noted that the firing temperature of the present scheme is measured by the British Porex temperature ring, which reflects the equivalent temperature corresponding to the comprehensive thermal effect experienced by the temperature ring at the placement position during the actual firing process.

[0043] Since the deformation influence degrees of satin glaze, full polishing glaze and high transmittance polishing glaze on ceramic tile products are completely different, in order to balance the tile shapes of the ceramic tile products corresponding to the three kinds of effect glazes, the present scheme first adjusts the surface temperature curve and the bottom temperature curve of the kiln, so that the obtained firing curve can match the formula characteristics of the three kinds of effect glazes. Then, the present scheme introduces face glazes with different expansion coefficients to match the above-mentioned three kinds of effect glazes respectively, to make up for the deformation caused by the three kinds of effect glazes, so as to adapt to the firing in the same kiln environment, ensure that the out-of-kiln deformation difference is small, and meet the quality standards.

[0044] It should be noted that the mixed firing process of the present scheme refers to that the glaze blanks of multiple ceramic tile products can be fired in the same kiln in the same batch, and the placement position of the glaze blank in step B in the large-capacity kiln is not limited. Specifically, the satin glaze glaze blank, the full polishing glaze glaze blank and the high-transparency polishing glaze glaze blank can be placed in three brick feeding positions in the same width direction of the large-capacity kiln, and the three brick feeding positions in other width directions are the same, that is, the placement mode of the embodiment; or, three satin glaze glaze blanks are placed in three brick feeding positions in the same width direction of the large-capacity kiln, then three full polishing glaze glaze blanks are placed in three brick feeding positions in the next width direction, and then three high-transparency polishing glaze glaze blanks are placed in three brick feeding positions in the next width direction, and so on; or, two satin glaze glaze blanks and one full polishing glaze glaze blank are placed in three brick feeding positions in the same width direction of the large-capacity kiln, then one full polishing glaze glaze blank and two high-transparency polishing glaze glaze blanks are placed in three brick feeding positions in the next width direction, and so on.

[0045] Further, the raw materials of the satin glaze are composed of potassium feldspar, sodium feldspar, kaolin, burned soil, dolomite, calcite, alumina, barium carbonate, zinc oxide and calcium-magnesium clinker, and the addition amount of the alumina is ≤1.5% according to the mass percentage; the silicon-aluminum ratio of the satin glaze is 2.6-2.8, and the content of Al2O3 in the satin glaze is 17.3-18.3%, the content of BaO is 2.9-3.3%, and the content of ZnO is 2.3-2.6% according to the mass percentage;

[0046] The raw materials of the full polishing glaze are composed of sodium feldspar, kaolin, burned soil, dolomite, quartz, calcite, alumina, zinc oxide and strontium carbonate; the silicon-aluminum ratio of the full polishing glaze is 3.0-3.2, and the content of Na2O in the full polishing glaze is 4.2-5.2%, and the content of SrO is 3.3-4.3% according to the mass percentage;

[0047] The raw materials of the high-transparency polishing glaze are composed of potassium feldspar, calcite, kaolin, wollastonite, burned talc, quartz, barium carbonate, barium sulfate, zinc oxide and calcium-potassium-zinc clinker, and the addition amount of quartz in the high-transparency polishing glaze is ≤8% according to the mass percentage; the chemical components of the high-transparency polishing glaze include Al2O3, CaO, BaO, ZnO and MgO, and the content of Al2O3 in the high-transparency polishing glaze is 6.7-7.7%, the content of CaO is 14.5-15.5, the content of BaO is 9.0-11.0%, the content of ZnO is 7.0-11.0%, and the content of MgO is ≤1.6% according to the mass percentage.

[0048] Since the effect glaze is the surface layer of the glazed tile, the physical and chemical properties such as gloss, wear resistance, acid and alkali resistance, color development performance and stain resistance should be considered. Therefore, in order to reduce the firing energy consumption while ensuring the realization of the physical and chemical properties of each effect glaze, the selection of raw materials and the content of key components of the effect glaze are limited.

[0049] For satin glaze:

[0050] Satin glaze, as the name implies, has a light touch and a light touch like silk, which is a delicate soft light glaze with a gloss of 10-18°. Since satin glaze does not need to go through the polishing step in the production process of ceramic tiles, the problem of pores in the glaze layer can be basically ignored in the formula design. Potassium feldspar is selected as the main flux of the formula, which helps to control the glaze defects due to the high initial melting point.

[0051] In the existing satin glaze, high alumina clay or aluminum compounds are generally used as matting agents. Since the above raw materials can be in a non-melting or semi-melting state during the firing process to produce no light, but the above high melting point aluminum source is easy to cause roughness of the glaze surface under the mechanism of low temperature fast firing. Therefore, in order to realize low temperature fast firing while considering the gloss and roughness of the glaze surface, high content of Al2O3 and barium carbonate are used as the main matting agent, and the aluminum source of Al2O3 is calcined clay, calcium magnesium clinker, kaolin and feldspar. At the same time, the addition amount of alumina in the raw material is controlled to effectively control the opalescence and roughness of the formula under the premise of matting, so that the glaze layer after firing can maintain a certain transparency.

[0052] In addition, the barium carbonate, dolomite and calcite in the glaze raw material introduce BaO, ZnO, CaO and MgO into the formula, which can form small crystals such as zinc silicate, anorthite, barium feldspar and diopside during the firing process, thereby obtaining a matte glaze surface, and the glaze surface is soft and delicate, like jade.

[0053] In the chemical composition of satin glaze, it has a high Al2O3, and the silica-alumina ratio (SiO2 / Al2O3) is limited to 2.6-2.8 (close to the theoretical value 2.0 of calcium feldspar CaAl2Si2O8) in this scheme, so that more calcium feldspar crystals are generated in the glaze layer, and the calcium feldspar crystals can form a refractive index difference with the glass phase, thereby causing a soft light effect, so that the glaze layer can simultaneously consider soft light and transparency.

[0054] In addition, the content of BaO is limited to 2.9-3.3%, the content of ZnO is limited to 2.3-2.6%, and Ba 2+ The crystallization temperature of the formula can be effectively reduced to the temperature range of 700-900℃, and Zn 2+Zn2SiO4) nucleation. With the low-temperature sintering mechanism of the present solution, a reasonable cooling speed can be achieved to ensure that the crystal size is ≥ 300 nm (controlled within the visible light wavelength range), microcrystalline transparency is achieved, and the crystallization is too small to cause the transparency to increase, resulting in the failure of the matte effect.

[0055] For full polishing glaze:

[0056] Polishing glaze is a kind of almost molten glass structure, and the raw material scheme of the present solution belongs to a raw transparent glaze, which is basically not opaque, has high light transmittance, strong penetration, good color development, and also has physical and chemical properties such as stain resistance, wear resistance, and corrosion resistance, and has a short sintering time.

[0057] Compared with traditional transparent full polishing glaze, the present solution selects sodium feldspar as the main flux in alkali metals, and dolomite, strontium carbonate, and zinc oxide as alkaline earth metals. Dolomite is a very cheap calcium-magnesium raw material in natural minerals; zinc oxide helps the polishing glaze formula to have excellent color development.

[0058] Strontium carbonate can replace CaO and ZnO in the formula in equal amounts during the sintering process, thereby further increasing the fluxing effect and increasing the fluidity. In addition, strontium carbonate can decompose into SrO (SrCO3→SrO+CO2↑) in the temperature range of 800-1000℃, and SrO can react with SiO2 to produce low-melting-point strontium silicate (SrSiO3), which can accelerate the formation of glaze layer vitrification and meet the requirements of low-temperature fast firing. In addition, the raw material formula of the present solution belongs to a low-viscosity formula (i.e., has a relatively low high-temperature viscosity), so that the micropores produced by the early decomposition of strontium silicate can also be quickly filled with low-viscosity melt and form a non-porous surface, achieving surface densification. At the same time, the low-viscosity formula can also cooperate with the rapid exhaust of other layers of the ceramic tile product (such as the body layer, etc.). It should be noted that since strontium silicate is completely decomposed before 1000℃, even under the low-temperature fast firing mechanism of the present solution, the pinholes caused by residual CO2 can be eliminated.

[0059] Further, the refractive index of SrO is 1.83, and the refractive index of strontium silicate formed in the vitrification reaction is 1.65. The introduction of strontium carbonate can also enhance the gloss of the glaze surface, reduce scattering, and form a mirror effect. Sr 2+ occupies the [SiO4] network gap, can hinder the nucleation and growth of silicate crystals (such as wollastonite and diopside), reduce the loss of transparency or crystalline spots of the glaze surface, and is very beneficial to maintaining the high transparency of the glaze layer.

[0060] Further, strontium carbonate is also a color development aid. SrO can replace part of CaO, reduce the oxidation tendency of Cr 3+ , and stabilize the pink color development. It is found in the test debugging process that this system is also very beneficial to the color development of red with zinc oxide.

[0061] In the chemical composition of the full polishing glaze, the SiO2 / Al2O3 ratio in the chemical composition is also limited, and the content of the fluxing components Na2O and SrO in the chemical composition is also optimized, so that the full polishing glaze forms a sodium-strontium system polishing glaze in the chemical composition. The traditional full polishing glaze is generally a potassium-barium system polishing glaze, which is sensitive to the content of silicon in the chemical composition. If the corrosion resistance of the glaze layer is improved by increasing the silicon content, the glaze pores will increase, thereby reducing the stain resistance of the glaze layer. Compared with the traditional potassium-barium system polishing glaze, the sodium-strontium system polishing glaze can simultaneously increase the contents of aluminum and silicon in the polishing glaze, while taking into account the corrosion resistance and stain resistance of the glaze layer.

[0062] For high-transparency polishing glaze:

[0063] The existing high-transparency polishing glaze (such as the black gold flower product) cannot simultaneously consider color development and glaze pores, and the main reason is that the existing high-transparency polishing glaze generally contains quartz which is beneficial to the color development of the glaze layer, but the excessive addition of quartz will destroy the sintering integrity of the glaze, and the un-melted quartz particles will hinder the formation of a continuous and dense glass phase after the glaze is melted, finally forming a large number of pores on the glaze surface and reducing the stain resistance of the glaze layer. In addition, the existing high-transparency polishing glaze generally selects calcined alumina as the aluminum source, but the high-melting-point alumina particles will form a significant refractive index difference with the glass phase, which will prevent the light from penetrating the glaze layer in a straight line, thereby reducing the transparency of the glaze layer.

[0064] Therefore, in order to solve the above problems, the high-transparency polishing glaze raw material scheme of the present scheme does not introduce alumina / calcined alumina, and the aluminum source is derived from potassium feldspar, kaolin and calcium-potassium-zinc frit in the raw materials, thereby avoiding the scattering of light by free Al2O3 (Al 3+ forms [AlO4] - scattering centers) in the glass, ensuring color development and transparency; in addition, the selection of potassium feldspar is based on the consideration of the initial melting point of the glaze and color development, to prevent the glaze from melting too early and producing pinholes and dissolved holes; the introduction of calcium-potassium-zinc frit can provide a low-temperature eutectic phase, shorten the melting time, and prevent the residual of bubbles in the glaze layer; the selection of wollastonite as the main material in the calcium source prevents the use of carbonates, which is mainly to ensure that the entire formula has a certain silicon content, to ensure the corrosion resistance in the later stage and control the generation of bubbles in the glaze layer; in addition, the introduction of calcium-potassium-zinc frit can also accelerate the melting of wollastonite (CaSiO3), avoid the scattering of residual crystals, and affect the transparency of the glaze layer. Barium carbonate and barium sulfate have a fluxing effect on potassium feldspar, but it is found that barium sulfate has a stronger fluxing effect on potassium feldspar than barium carbonate, which can effectively reduce the generation of glaze pores. In addition, the calcium-potassium-zinc frit in the raw materials can also reduce the initial melting temperature of barium sulfate to 950°C, leaving sufficient exhaust time for the decomposition of sulfates, avoiding the formation of pinholes by the residual sulfur, and in the process of releasing SO3 to generate micro-bubbles by BaSO4, the bubbles can play a certain stirring effect on the melt, assisting the exhaust of the melt.

[0065] In the chemical composition of high-transparency glaze, in order to ensure the purity of the color, the present scheme selects CaO, BaO and ZnO as the main flux of the formula, the main reason is that Ba 2+ Large ionic radius (1.35 Å), controlling its content can significantly reduce the refractive index gradient of glass, reduce interface scattering, enhance the transparency, in addition, it can also enhance the color saturation of ink. ZnO can also effectively promote the homogenization of the melt, inhibit the phase separation caused by opalescence, and achieve the effect of improving the transparency. In addition, the content of MgO must be strictly controlled to prevent the black pigment in the ink from turning green.

[0066] Further, according to the mass percentage, the chemical composition of the satin glaze includes SiO246.8-51.3%, Al2O317.3-18.3%, Fe2O30.15-0.25%, TiO20.1-0.2%, CaO 7.4-8.6%, MgO 2.4-3.4%, K2O 4.0-4.6%, Na2O 1.8-2.4%, BaO 2.9-3.3%, ZnO 2.3-2.6%, and loss on ignition 6.5-9.6%;

[0067] According to the mass percentage, the chemical composition of the full polishing glaze includes SiO245.0-49.0%, Al2O314.7-15.6%, Fe2O30.1-0.2%, TiO20.05-0.1%, CaO 8.5-9.5%, MgO 2.5-3.5%, K2O 0.1-0.3%, Na2O 4.2-5.2%, ZnO 3.4-4.4%, SrO 3.3-4.3%, and loss on ignition 8.0-12.0%;

[0068] According to the mass percentage, the chemical composition of the high-transparency glaze includes SiO243.5-45.5%, Al2O36.7-7.7%, Fe2O30.1-0.2%, TiO20.04-0.06%, CaO 14.5-15.5%, MgO 1.2-1.6%, K2O 3.1-4.1%, Na2O 0.4-0.9%, BaO 9.0-11.0%, ZnO 7.0-11.0%, and loss on ignition 7.5-8.5%.

[0069] Further, in order to ensure the stability of the glaze layer during the firing process, while meeting the performance requirements of the present case, the present scheme proposes a specific embodiment of the chemical composition of the satin glaze, the full polishing glaze and the high-transparency glaze.

[0070] In one specific embodiment, the raw materials of the satin luster glaze are composed of potassium feldspar 44.4%, sodium feldspar 7%, kaolin 6%, burned soil 10%, dolomite 10%, calcite 5.6%, alumina 1%, barium carbonate 4%, zinc oxide 2.5%, and calcium-magnesium clinker 9.5% by mass percentage, and the chemical composition of the calcium-magnesium clinker includes SiO244.17%, Al2O319.96%, Fe2O30.21%, TiO20.47%, CaO 15.5%, MgO 5.66%, K2O 0.62%, Na2O 1.03%, and loss on ignition 0.05% by mass percentage;

[0071] The raw materials of the full-polish glaze are composed of sodium feldspar 52.5%, kaolin 6%, burned soil 6%, dolomite 15%, quartz 2%, calcite 7%, alumina 2%, zinc oxide 4%, and strontium carbonate 5.5% by mass percentage;

[0072] The raw materials of the high-transparency polish glaze are composed of potassium feldspar 23%, calcite 9%, kaolin 5%, wollastonite 18.5%, burned talc 3%, quartz 6%, barium carbonate 6%, barium sulfate 7.5%, zinc oxide 6%, and calcium-potassium-zinc clinker 16% by mass percentage, and the chemical composition of the calcium-potassium-zinc clinker includes SiO259.15%, Al2O36.93%, Fe2O30.13%, TiO20.09%, CaO 12.44%, MgO 0.35%, K2O 6.73%, Na2O 0.26%, BaO 2.55%, ZnO 11.21%, and loss on ignition 0.06% by mass percentage.

[0073] Further, the water absorption of the body layer of the satin luster glaze blank, the body layer of the full-polish glaze blank, and the body layer of the high-transparency polish glaze blank is ≤0.5% by mass percentage after the firing of step B;

[0074] The body layer of the satin luster glaze blank, the body layer of the full-polish glaze blank, and the body layer of the high-transparency polish glaze blank are all pressed from low-hygroscopic powder, and the low-hygroscopic powder is prepared by a wet powder preparation process;

[0075] The chemical composition of the low-hygroscopic powder includes Al2O3, CaO, MgO, K2O, and Na2O, and the content of Al2O3 in the low-hygroscopic powder is 17.2-18.2% by mass percentage, the total content of CaO, MgO, K2O, and Na2O is 5.6-6.6% by mass percentage, the content of CaO is ≥0.8% by mass percentage, the content of MgO is ≥1.8% by mass percentage, the content of K2O is ≥1.5% by mass percentage, and the content of Na2O is ≥1.5% by mass percentage.

[0076] In the prior art, the green body is softened at the high temperature section of the kiln, and due to insufficient skeleton strength, it is prone to deformation under the action of its own gravity and the friction of the roller bar, thereby forming a roller bar print. In particular, when producing products with a water absorption <0.1%, the problem of roller bar print is more obvious, because it is necessary to consider that the water absorption of the product is in an extremely low range, and it is also necessary to ensure that the production efficiency is relatively high (i.e., a relatively short firing period), at this time, it is easy to cause the sintering degree inside the green body to be too high, and the surface layer of the green body will appear a softened roller bar print caused by overfiring. In view of the above situation, the common solution in the industry is to reduce the firing speed of the product (i.e., adjust the kiln), so that the temperature of the surface layer and the inside of the green body will not differ greatly, so as to realize low water absorption while preventing the surface layer of the green body from being excessively softened.

[0077] In one preferred embodiment of the present technical solution, in order to meet the market demand for high-value and high-performance ceramic products (the present solution refers to a green body with a water absorption ≤0.5% and made of wet-process powder), adapt to the firing curve of the large-capacity kiln in the present solution, and have good adaptability to three types of effect glazes, the present solution optimizes the chemical composition of the green body layer to improve the roller bar print caused by excessive softening during high-temperature firing.

[0078] Specifically, the present solution first controls the content of Al2O3 in the low-hygroscopic wet-process powder to be 17.2-18.2%, so as to avoid the softening of the green body caused by excessively low content, which may cause defects such as roller bar print and deformation of the green body, and also prevent the green body formula from requiring a high firing temperature, which cannot realize the low-temperature and fast-firing mechanism required by the present solution.

[0079] Further, in order to adapt to the content of Al2O3 in the formula, the present solution designs the fluxing system of the green body formula as a CaO-MgO-K2O-Na2O quaternary system, controls the content of each fluxing component in addition to the total content of the fluxing components, and uses the gradient fluxing effect brought by the quaternary fluxing system to prevent the product from being excessively softened due to the sharp softening of the liquid phase caused by a single fluxing component during high-temperature firing.

[0080] It should be noted that the water absorption of the green body is mainly reflected in the strength of the ceramic product, and the strength of the ceramic product also determines its market positioning. Generally speaking, the lower the water absorption, the higher the strength of the ceramic product, and it is suitable for the middle and high-end market. In addition, in the preparation process of the ceramic green body, the powder preparation process of the green body powder mainly includes wet powder preparation and dry powder preparation process: the process flow of wet powder preparation is mainly to first add water to the prepared green body raw material for wet ball milling to prepare slurry, and then spray the slurry through a spray tower to prepare powder. The prepared powder particles have the characteristics of low hardness, large particle size and low fine powder content; the process flow of dry powder preparation is mainly to first remove iron and crush the prepared green body raw material, and then pass through a vertical dry mill to prepare powder to obtain fine powder with the required moisture content, and then add water to the fine powder after removing iron and slag to obtain powder with a particle size that meets the production requirements. The prepared powder particles have the characteristics of high hardness, small particle size and high fine powder content. Relatively speaking, although the dry powder preparation method is prone to small pits on the surface of the green body, the flatness is poor, the orange peel effect is obvious, and the green body may have black core and black spot phenomenon after firing, but due to its obvious energy saving and low cost advantages, it is mainly suitable for volume market and engineering order products; while the wet powder preparation process has high energy consumption, but the green body quality is higher, so it is mainly suitable for the middle and high-end market.

[0081] Further, according to the mass percentage, the chemical composition of the low-hygroscopic powder includes SiO266.4-67.5%, Al2O317.2-18.2%, Fe2O31.6-2.7%, TiO20.3-0.5%, CaO 0.8-1.2%, MgO 1.8-2.3%, K2O 1.5-1.6%, Na2O 1.5-1.8%, and ignition loss 4.8-5.5%.

[0082] Further, in order to ensure the stability of the performance of the green body in the whole process of forming, drying and firing, and at the same time meet the performance requirements of the present case, the present case proposes an embodiment of the chemical composition of the low-hygroscopic powder. In a specific embodiment, the present case also controls the ignition loss (I.L) of the low-hygroscopic powder formula to be below 5.5%, in order to reduce the gaseous products of the green body, further ensure the quality of the green body, and meet the market demand for high-value and high-performance ceramic products.

[0083] It should be noted that those skilled in the art can configure the chemical composition of the low-hygroscopic powder in the present case according to the local raw material resource situation, and the present case does not limit the composition and ratio of the raw material scheme.

[0084] Preferably, according to the mass percentage, the raw materials of the low-hygroscopic powder are composed of 3% bentonite, 12% bauxite, 32% green sand, 2.5% magnesia soil, 5% broken brick powder, 8% mixed mud, 4% washed mud, 7% edge polishing mud, 1.5% talc and 25% yellow sand.

[0085] In one preferred embodiment of the technical solution, a specific raw material ratio scheme for the low-hygroscopic powder is also proposed.

[0086] In the raw material formula, the main role of bentonite is to improve the plasticity and strength of the body during shaping and transportation, and to reduce the occurrence of rotten bricks.

[0087] The addition amount of bauxite in the raw material formula is controlled at 12%, and mixed mud and washed mud are introduced into the raw material formula as a supplement of Al2O3 in the chemical composition. Since the main mineral of mixed mud and washed mud is kaolinite, compared with multi-water hard / soft alumina, kaolinite is easier to sinter, and thus can better match the low-temperature fast-firing mechanism of the present scheme.

[0088] Green sand is a kind of sand material mainly produced in Rongchang and Yongchuan districts of Chongqing, and is a special ceramic raw material in the local area. This kind of raw material has good sintering plasticity, large reserves, and is easy to obtain. If it is added in large quantities in the body formula, the raw material cost can be greatly reduced. In addition, due to the chemical composition of green sand also containing a certain amount of MgO, K2O and Na2O, green sand has good fluxing effect.

[0089] Magnesia is the main source of MgO in the chemical composition, and has fluxing and whitening effects to some extent. In addition, talc is a supplementary source of MgO in the chemical composition, and the combination of the two can increase the stability of the formula.

[0090] Yellow sand is also a cheap and white raw material in Chongqing, which has good economic benefits. However, due to the extremely low content of Al2O3 in the raw material, excessive use will lead to a decrease in the overall Al2O3 content of the formula, causing the softening of the body.

[0091] Rotten brick powder is a clinker formed by crushing the secondary waste product after firing. When the clinker is added to the raw material composed of other raw materials, it can promote the fast firing of the body layer and further reduce the production energy consumption of the body, thereby effectively promoting the rapid firing of the body and shortening the firing period. At the same time, it can replace the traditional feldspar material as a fluxing component in the formula, which has obvious fluxing effect and can effectively reduce the raw material cost.

[0092] Edge polishing mud is a common waste in the field of building ceramics, which is mainly produced in the process of grinding and polishing of ceramic tiles. Its main minerals are glass phase, quartz and mullite, and it also contains a small amount of silicon carbide and grinding block resin, which is easy to foam. As a solid waste material, the cost of outsourcing treatment is relatively high, and it is usually used in body formula to reduce the cost of formula. However, in the process of use, it is necessary to strictly control its use in low water absorption body (water absorption ≤0.5%), because the low water absorption body produces more liquid phase in the high temperature firing process (used to support the density of the body), which will affect the exhaust of the easy foaming materials such as silicon carbide and resin in the edge polishing mud, thereby affecting the glaze quality of the ceramic tile products using the above body.

[0093] Further, the size of the body layer of the satin gloss glaze, the full polishing glaze and the high permeability polishing glaze is 800mmx800mm, and in the large capacity kiln, the front side edge of all body layers along the conveying direction forms an angle one with the width direction of the large capacity kiln, and the angle of the angle one is 5-11°.

[0094] Further, the size of the body layer of the satin gloss glaze, the full polishing glaze and the high permeability polishing glaze is 800mmx800mm, and in the large capacity kiln, the front side edge of all body layers along the conveying direction forms an angle one with the width direction of the large capacity kiln, and the angle of the angle one is 5-11°.

[0095] As shown in Figure 1 ∠A, which is an angle one diagram formed by the 800 specification (i.e. 800mmx800mm) ceramic tile product and the width direction of the large capacity kiln in the present scheme. As shown in Figure 2 ∠B, which is an angle two diagram formed by the 715 specification (i.e. 750mmx1500mm) ceramic tile product and the width direction of the large capacity kiln in the present scheme, i.e. the angle formed by the short side of the body layer (the edge of 750mm) and the width direction of the large capacity kiln.

[0096] In the mixed firing process of the present scheme, the body layer is placed on the roller at a certain small angle before entering the kiln, which can significantly improve the roller mark defects after firing. The core principle lies in changing the contact state and stress mode of the body layer and the roller, thereby reducing the local deformation and stress concentration of the brick body in the high temperature plastic stage. The specific reasons are as follows:

[0097] Firstly, when the body layer is placed horizontally, the roller exerts force on the edge of the body layer, which is equivalent to the fulcrum at the center of the body layer, and the edge is easy to bend and deform. When the body layer is placed obliquely, the edge of the body layer is close to the support point of the roller, the force arm is shortened, and the deformation is naturally reduced.

[0098] Second, when the green body layer is placed horizontally, only two narrow edges contact the roller, and the pressure is easy to concentrate; when the green body layer is placed obliquely, the contact line is long, and the unit area pressure is dispersed.

[0099] Second, when the green body layer is placed horizontally, the shrinkage of the green body layer is resisted by the frictional resistance of the roller, and the two sides form inward pulling stress, which is easy to form marks at the edges. When the green body layer is placed obliquely, the direction of the frictional force changes, and is decomposed into axial and transverse components, the transverse component is reduced, and the longitudinal shrinkage is more free.

[0100] Further, the expansion coefficient of the low-expansion glaze is (6.6-6.8) x 10 -6 / ℃; according to mass fraction, the raw materials of the low-expansion glaze include 36-40 parts of sodium feldspar, 9-11 parts of kaolin, 2-4 parts of quartz, 7-9 parts of nepheline, 10-14 parts of alumina, 10-14 parts of potassium feldspar, 14-16 parts of burned soil, 1-3 parts of burned talc, and 10-14 parts of zirconium silicate;

[0101] The expansion coefficient of the medium-expansion glaze is (7.3-7.5) x 10 -6 / ℃; according to mass fraction, the raw materials of the medium-expansion glaze include 38-42 parts of sodium feldspar, 9-11 parts of kaolin, 4-6 parts of quartz, 9-11 parts of nepheline, 12-16 parts of alumina, 10-14 parts of potassium feldspar, 5-7 parts of burned soil, 2-4 parts of burned talc, and 10-14 parts of zirconium silicate;

[0102] The expansion coefficient of the high-expansion glaze is (7.9-8.1) x 10 -6 / ℃; according to mass fraction, the raw materials of the high-expansion glaze include 36-40 parts of sodium feldspar, 9-11 parts of kaolin, 19-22 parts of quartz, 14-16 parts of nepheline, 14-16 parts of alumina, 1-3 parts of burned talc, and 10-14 parts of zirconium silicate.

[0103] In order to simplify the preparation process of glazes with different expansion coefficients, the raw material ratio of the glaze is also optimized in the present scheme. On the basis of small changes in the types of raw materials, only the ratio of the raw materials needs to be simply adjusted to obtain the glazes with different expansion coefficients required for production, thereby improving the production efficiency of ceramic tile products.

[0104] Preferably, according to mass fraction, the raw materials of the low-expansion glaze include 38 parts of sodium feldspar, 10 parts of kaolin, 3 parts of quartz, 8 parts of nepheline, 12 parts of alumina, 12 parts of potassium feldspar, 15 parts of burned soil, 2 parts of burned talc, and 12 parts of zirconium silicate;

[0105] According to mass fraction, the raw materials of the medium-expansion glaze include 40 parts of sodium feldspar, 10 parts of kaolin, 5 parts of quartz, 10 parts of nepheline, 14 parts of alumina, 12 parts of potassium feldspar, 6 parts of burned soil, 3 parts of burned talc, and 12 parts of zirconium silicate;

[0106] According to the mass fractions, the raw materials of the high-expansion glaze include 38 parts of albite, 10 parts of kaolin, 20 parts of quartz, 15 parts of nepheline, 15 parts of alumina, 2 parts of calcined talc, and 12 parts of zirconium silicate.

[0107] To further clarify, the application amount of the low-swell glaze, the satin glaze, the medium-swell glaze, the fully polished glaze, the high-swell glaze, and the high-transparency polished glaze is all 420–480 g / m². 2 .

[0108] Furthermore, the inkjet volume of the color ink for the satin-finish glaze blank, the color ink for the fully polished glaze blank, and the color ink for the high-transparency polished glaze blank are all 4.8–9.6 g / m³. 2 .

[0109] The amount of glaze applied and the amount of ink sprayed can also affect the deformation of the ceramic tile products after firing to a certain extent. Therefore, in order to balance the production cost and production quality of ceramic tile products, this solution also optimizes the amount of glaze applied and the amount of ink sprayed in each ceramic tile product.

[0110] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0111] Example

[0112] A. Preparation of satin-glazed blanks, fully polished blanks, and high-transparency polished blanks;

[0113] B. Place the satin glaze blank, the fully polished glaze blank, and the high-transparency polished glaze blank in three brick feeding positions in the same width direction in a high-capacity kiln. Each satin glaze blank, fully polished glaze blank, and high-transparency polished glaze blank in the same width direction constitutes a firing unit. There are a total of 100 firing units. The angle formed between the front edge of all glaze blanks along the conveying direction and the width direction of the high-capacity kiln is 8°.

[0114] Firing is carried out at a firing temperature of ≤1100℃ and a firing cycle of ≤30min.

[0115] in,

[0116] In step A, the satin glaze blank includes a blank layer, and a low-expansion surface glaze, colored ink and satin glaze are applied sequentially from bottom to top on the top surface of the blank layer;

[0117] In the satin-glazed body, the coefficient of thermal expansion of the low-expansion surface glaze is 6.7 × 10⁻⁶. -6The low-expansion glaze has a raw material including 38 parts of sodium feldspar, 10 parts of kaolin, 3 parts of quartz, 8 parts of nepheline, 12 parts of alumina, 12 parts of potassium feldspar, 15 parts of burned soil, 2 parts of burned talc, and 12 parts of zirconium silicate, and the glazing amount of the low-expansion glaze is 450 g / m 2 .

[0118] The inkjet amount of the color ink in the satin luster glaze body is 7.2 g / m 2 .

[0119] The raw material of the satin luster glaze includes potassium feldspar, sodium feldspar, kaolin, burned soil, dolomite, calcite, alumina, barium carbonate, zinc oxide, and calcium-magnesium clinker, and according to the mass percentage, the chemical composition of the calcium-magnesium clinker includes SiO244.17%, Al2O319.96%, Fe2O30.21%, TiO20.47%, CaO 15.5%, MgO 5.66%, K2O 0.62%, Na2O 1.03%, and loss on ignition 0.05%, and the remaining content is inevitable impurities in the chemical composition; the satin luster glaze is obtained by reasonably configuring the above raw materials, and according to the mass percentage, the chemical composition of the satin luster glaze includes SiO249.02%, Al2O317.87%, Fe2O30.2%, TiO20.13%, CaO 7.94%, MgO 2.61%, K2O 4.26%, Na2O 1.97%, BaO 3.11%, ZnO 2.48%, and loss on ignition 7.85%, and the remaining content is inevitable impurities in the formula system. The glazing amount of the satin luster glaze is 450 g / m 2 .

[0120] The full-polish glaze body includes a body layer, and a middle-expansion glaze, color ink, and full-polish glaze are sequentially applied on the top surface of the body layer from bottom to top;

[0121] The expansion coefficient of the middle-expansion glaze in the full-polish glaze body is 7.4×10 -6 / ℃, and according to the mass fraction, the raw material of the middle-expansion glaze includes 40 parts of sodium feldspar, 10 parts of kaolin, 5 parts of quartz, 10 parts of nepheline, 14 parts of alumina, 12 parts of potassium feldspar, 6 parts of burned soil, 3 parts of burned talc, and 12 parts of zirconium silicate. The glazing amount of the middle-expansion glaze is 450 g / m 2 .

[0122] The inkjet amount of the color ink in the full-polish glaze body is 7.2 g / m 2 .

[0123] The full polishing enamel body comprises a body layer, and a high-expansion face glaze, color ink and high-transparency polishing enamel are sequentially applied on the top surface of the body layer from bottom to top. 2 .

[0124] The high-transparency polishing enamel body comprises a body layer, and a high-expansion face glaze, color ink and high-transparency polishing enamel are sequentially applied on the top surface of the body layer from bottom to top.

[0125] In the high-transparency polishing enamel body, the expansion coefficient of the high-expansion face glaze is 8.0×10 -6 / ℃, and according to mass fraction, the raw materials of the high-expansion face glaze comprise 38 parts of sodium feldspar, 10 parts of kaolin, 20 parts of quartz, 15 parts of nepheline, 15 parts of aluminum oxide, 2 parts of calcined talc and 12 parts of zirconium silicate. The application amount of the high-expansion face glaze is 450 g / m 2 .

[0126] In the high-transparency polishing enamel body, the inkjet amount of the color ink is 7.2 g / m 2 .

[0127] In the high-transparency polishing enamel body, the raw materials of the high-transparency polishing enamel comprise potassium feldspar, calcite, kaolin, wollastonite, calcined talc, quartz, barium carbonate, barium sulfate, zinc oxide and calcium potassium zinc clinker, and according to mass percentage, the chemical composition of the calcium potassium zinc clinker comprises SiO259.15%, Al2O36.93%, Fe2O30.13%, TiO20.09%, CaO 12.44%, MgO 0.35%, K2O 6.73%, Na2O 0.26%, BaO 2.55%, ZnO 11.21% and loss on ignition 0.06%, and the remaining content is an unavoidable impurity in the chemical composition; the high-transparency polishing enamel is obtained by reasonably configuring the above-mentioned raw materials, and according to mass percentage, the chemical composition of the high-transparency polishing enamel comprises SiO244.6%, Al2O37.23%, Fe2O30.18%, TiO20.05%, CaO 15.12%, MgO 1.58%, K2O 3.69%, Na2O 0.76%, BaO 10.0%, ZnO 7.73% and loss on ignition 8.2%, and the remaining content is an unavoidable impurity in the formula system. The application amount of the high-transparency polishing enamel is 450 g / m 2 .

[0128] The body layer of the satin luster glaze blank, the body layer of the full polishing glaze blank and the body layer of the high-transparency polishing glaze blank are all pressed from low-hygroscopic powder, and the low-hygroscopic powder is prepared by a wet powder preparation process. According to mass percentage, the raw materials of the low-hygroscopic powder are composed of 3% of bentonite, 12% of bauxite, 32% of green sand, 2.5% of magnesia clay, 5% of broken brick powder, 8% of mixed clay, 4% of water-washed clay, 7% of edge polishing clay, 1.5% of talc and 25% of yellow sand, and according to mass percentage, the chemical composition of the low-hygroscopic powder prepared from the above-mentioned raw materials of the formula includes 66.77% of SiO2, 17.71% of Al2O3, 1.85% of Fe2O3, 0.35% of TiO2, 0.92% of CaO, 2.16% of MgO, 1.56% of K2O, 1.67% of Na2O and 4.98% of loss on ignition, and the remaining content is inevitable impurities in the formula system. The size of the body layer of the satin luster glaze blank, the body layer of the full polishing glaze blank and the body layer of the high-transparency polishing glaze blank is all 800mm×800mm, and the thickness is all 10mm.

[0129] It should be noted that the chemical composition of the raw materials of the above-mentioned low-hygroscopic powder is respectively as follows:

[0130] According to mass percentage, the chemical composition of the bauxite includes 41.64% of SiO2, 40.99% of Al2O3, 1.59% of Fe2O3, 1.08% of TiO2, 0.29% of CaO, 0.38% of MgO, 0.65% of K2O, 0.31% of Na2O and 12.89% of loss on ignition.

[0131] According to mass percentage, the chemical composition of the bentonite includes 68.45% of SiO2, 14.57% of Al2O3, 0.81% of Fe2O3, 0.11% of TiO2, 1.48% of CaO, 1.59% of MgO, 2.91% of K2O, 1.67% of Na2O and 7.02% of loss on ignition.

[0132] According to mass percentage, the chemical composition of the green sand includes 69.51% of SiO2, 14.73% of Al2O3, 3.19% of Fe2O3, 0.31% of TiO2, 1.41% of CaO, 1.83% of MgO, 1.74% of K2O, 3.87% of Na2O and 2.59% of loss on ignition.

[0133] The chemical composition of the magnesia soil includes, in mass percent, SiO2 62.59%, Al2O3 5.79%, Fe2O3 1.62%, TiO2 0.13%, CaO 0.79%, MgO 21.41%, K2O 0.25%, Na2O 0.25%, and loss on ignition 6.04%.

[0134] The chemical composition of the rotten brick powder includes, in mass percent, SiO2 65.67%, Al2O3 18.0%, Fe2O3 1.75%, TiO2 0.5%, CaO 0.62%, MgO 1.77%, K2O 1.92%, and Na2O 2.09%.

[0135] The chemical composition of the mixed mud includes, in mass percent, SiO2 69.35%, Al2O3 20.5%, Fe2O3 0.94%, TiO2 0.43%, CaO 0.98%, MgO 0.3%, K2O 1.06%, Na2O 0.17%, and loss on ignition 7.21%.

[0136] The chemical composition of the washed mud includes, in mass percent, SiO2 49.1%, Al2O3 33.74%, Fe2O3 2.11%, TiO2 0.2%, CaO 0.23%, MgO 0.58%, K2O 2.56%, Na2O 0.31%, and loss on ignition 11.09%.

[0137] The chemical composition of the edge-ground and polished mud includes, in mass percent, SiO2 67.48%, Al2O3 18.0%, Fe2O3 1.6%, TiO2 0.38%, CaO 2.12%, MgO 2.46%, K2O 2.05%, Na2O 2.14%, and loss on ignition 1.77%.

[0138] The chemical composition of the talc includes, in mass percent, SiO2 32.24%, Al2O3 0.69%, Fe2O3 0.22%, TiO2 0.03%, CaO 1.76%, MgO 37.57%, K2O 0.01%, Na2O 0.09%, and loss on ignition 27.0%.

[0139] The chemical composition of the yellow sand includes, in mass percent, SiO2 79.63%, Al2O3 9.53%, Fe2O3 0.65%, TiO2 0.22%, CaO 0.24%, MgO 0.32%, K2O 1.63%, Na2O 0.22%, and loss on ignition 2.8%.

[0140] In step B, the firing curve of the large-capacity kiln includes a preheating section, a preheating section, a medium temperature section, a high temperature section, a rapid cooling section and a slow cooling section: the surface temperature of the preheating section rises from room temperature to 950℃, the bottom temperature rises from room temperature to 1100℃, and the time consumption is 3.65min; the surface temperature of the preheating section rises from 950℃ to 1110℃, the bottom temperature drops from 1100℃ to 1060℃, and the time consumption is 2.09min; the surface temperature of the medium temperature section rises from 1110℃ to 1203℃, the bottom temperature rises from 1060℃ to 1226℃, and the time consumption is 7.82min; the surface temperature of the high temperature section is 1203℃, the bottom temperature is 1226℃, and the time consumption is 4.43min; the surface temperature of the rapid cooling section drops from 1203℃ to 570℃, the bottom temperature drops from 1226℃ to 300℃, and the time consumption is 4.83min; the surface temperature of the slow cooling section drops from 570℃ to room temperature, the bottom temperature drops from 300℃ to room temperature, and the time consumption is 6.52min.

[0141] After firing in step B, 10 firing units are randomly selected from 100 firing units, and the performance of the fired products in the 10 firing units is tested according to the test methods of GB / T 4100-2015 and GB / T 45817-2025, and the results are shown in Table 1.

[0142] Table 1 Performance test results of each fired product in the example

[0143]

[0144] From the performance test results in Table 1, it can be seen that the present scheme can realize low-temperature fast firing of satin glaze ceramic tiles, full-polished glaze ceramic tiles and high-transparency polished glaze ceramic tiles in the same kiln, and the fired ceramic tile products not only meet the physical and chemical properties of the corresponding effect glaze, but also balance the shapes of the three types of ceramic tiles. The performance test results of the roller bar printing meet the standard of GB / T 45817-2025, and the remaining performance test results meet the standard of GB / T 4100-2015.

[0145] The technical principles of the present application are described above in conjunction with specific embodiments. These descriptions are only to explain the principles of the present application, and cannot be interpreted in any way as a limitation on the scope of protection of the present application. Based on the explanations here, those skilled in the art can think of other specific embodiments of the present application without creative effort, and these embodiments will fall within the scope of protection of the present application.

Claims

1. A multi-glazed tile co-firing process with various glaze effects, characterized in that, This method is applicable to high-capacity kilns, wherein the high-capacity kiln has three brick-feeding positions in the width direction, and the co-firing process includes the following steps: A. Prepare multiple glaze blanks, including satin glaze blanks, fully polished glaze blanks, and high-transparency polished glaze blanks; B. Multiple glazed blanks are sequentially conveyed to the brick feeding position of the high-capacity kiln and fired in an environment with a firing temperature ≤1100℃ and a firing cycle ≤30min. In step A, the satin glaze blank includes a blank layer, and low-expansion surface glaze, colored ink, and satin glaze are applied sequentially from bottom to top on the top surface of the blank layer; the fully polished glaze blank includes a blank layer, and medium-expansion surface glaze, colored ink, and fully polished glaze are applied sequentially from bottom to top on the top surface of the blank layer; the high-transparency polished glaze blank includes a blank layer, and high-expansion surface glaze, colored ink, and high-transparency polished glaze are applied sequentially from bottom to top on the top surface of the blank layer. The body layers of the satin-glazed glaze blank, the full-polished glaze blank, and the high-transparency polished glaze blank are all pressed from low-moisture-absorbing powder, which is obtained by a wet powder-making process. The chemical composition of the low-moisture-absorbing powder includes Al2O3, CaO, MgO, K2O, and Na2O. By mass percentage, the content of Al2O3 in the low-moisture-absorbing powder is 17.2-18.2%, the total content of CaO, MgO, K2O, and Na2O is 5.6-6.6%, the content of CaO is ≥0.8%, the content of MgO is ≥1.8%, the content of K2O is ≥1.5%, and the content of Na2O is ≥1.5%. The coefficient of thermal expansion of the low-expansion glaze is (6.6~6.8)×10. -6 / ℃, the coefficient of thermal expansion of the medium-expansion glaze is (7.3~7.5)×10 -6 The coefficient of thermal expansion of the high-expansion glaze is (7.9~8.1)×10 at / ℃. -6 / ℃; In step B, the firing curve of the high-capacity kiln includes a preheating section, a preheating section, a medium-temperature section, a high-temperature section, a rapid cooling section, and a slow cooling section: In the preheating section, the surface temperature rises from room temperature to 950°C, and the bottom temperature rises from room temperature to 1100°C, taking 3.5–3.7 minutes; in the preheating section, the surface temperature rises from 950°C to 1110°C, and the bottom temperature drops from 1100°C to 1060°C, taking 2–2.2 minutes; in the medium-temperature section, the surface temperature rises from 1110°C to 1203°C, and the bottom temperature… The temperature rises from 1060℃ to 1226℃ in 7.7–7.9 minutes; the surface temperature of the high-temperature section is maintained at 1203℃ and the bottom temperature at 1226℃ in 4.3–4.5 minutes; the surface temperature of the rapid cooling section drops from 1203℃ to 570℃ and the bottom temperature drops from 1226℃ to 300℃ in 4.7–4.9 minutes; the surface temperature of the slow cooling section drops from 570℃ to room temperature and the bottom temperature drops from 300℃ to room temperature in 6.4–6.6 minutes. The firing temperature is determined by the British POLORS temperature measuring ring and reflects the equivalent temperature corresponding to the comprehensive thermal effect experienced at the location where the temperature measuring ring is placed during the entire actual firing process.

2. The multi-glaze effect glazed tile co-firing process according to claim 1, characterized in that, The raw materials for the satin glaze consist of potassium feldspar, sodium feldspar, kaolin, calcined clay, dolomite, calcite, alumina, barium carbonate, zinc oxide, and calcium magnesium frit, with the alumina content ≤1.5% by mass. The silica-alumina ratio of the satin glaze is 2.6–2.8, and the Al2O3 content, BaO content, and ZnO content in the satin glaze are 17.3–18.3% and 2.9–3.3% by mass, respectively. The raw materials for the fully polished glaze are composed of albite, kaolin, calcined clay, dolomite, quartz, calcite, alumina, zinc oxide, and strontium carbonate; the silica-alumina ratio of the fully polished glaze is 3.0–3.2, and by mass percentage, the Na₂O content in the fully polished glaze is 4.2–5.2%, and the SrO content is 3.3–4.3%. The raw materials of the high-transparency polished glaze consist of potassium feldspar, calcite, kaolin, wollastonite, calcined talc, quartz, barium carbonate, barium sulfate, zinc oxide, and calcium-potassium-zinc frit. The amount of quartz added to the high-transparency polished glaze is ≤8% by mass percentage. The chemical composition of the high-transparency polished glaze includes Al2O3, CaO, BaO, ZnO, and MgO. The content of Al2O3 in the high-transparency polished glaze is 6.7–7.7%, the content of CaO is 14.5–15.5%, the content of BaO is 9.0–11.0%, the content of ZnO is 7.0–11.0%, and the content of MgO is ≤1.6% by mass percentage.

3. The multi-glaze effect glazed tile co-firing process according to claim 2, characterized in that, According to mass percentage, the chemical composition of the satin glaze includes SiO2 46.8-51.3%, Al2O3 17.3-18.3%, Fe2O3 0.15-0.25%, TiO2 0.1-0.2%, CaO 7.4-8.6%, MgO 2.4-3.4%, K2O 4.0-4.6%, Na2O 1.8-2.4%, BaO 2.9-3.3%, ZnO 2.3-2.6%, and loss on ignition 6.5-9.6%. According to mass percentage, the chemical composition of the fully polished glaze includes SiO2 45.0-49.0%, Al2O3 14.7-15.6%, Fe2O3 0.1-0.2%, TiO2 0.05-0.1%, CaO 8.5-9.5%, MgO 2.5-3.5%, K2O 0.1-0.3%, Na2O 4.2-5.2%, ZnO 3.4-4.4%, SrO 3.3-4.3%, and loss on ignition 8.0-12.0%. According to mass percentage, the chemical composition of the high-transparency polished glaze includes SiO2 43.5-45.5%, Al2O3 6.7-7.7%, Fe2O3 0.1-0.2%, TiO2 0.04-0.06%, CaO 14.5-15.5%, MgO 1.2-1.6%, K2O 3.1-4.1%, Na2O 0.4-0.9%, BaO 9.0-11.0%, ZnO 7.0-11.0%, and loss on ignition 7.5-8.5%.

4. The multi-glaze effect glazed tile co-firing process according to claim 1, characterized in that, According to the mass percentage, after firing in step B, the water absorption rate of the body layer of the satin glaze blank, the body layer of the fully polished glaze blank, and the body layer of the high-transparency polished glaze blank are all ≤0.5%.

5. The multi-glaze effect glazed tile co-firing process according to claim 4, characterized in that, The chemical composition of the low-hygroscopic powder, by mass percentage, includes SiO2 66.4–67.5%, Al2O3 17.2–18.2%, Fe2O3 1.6–2.7%, TiO2 0.3–0.5%, CaO 0.8–1.2%, MgO 1.8–2.3%, K2O 1.5–1.6%, Na2O 1.5–1.8%, and loss on ignition 4.8–5.5%.

6. The multi-glaze effect glazed tile co-firing process according to claim 4, characterized in that, The blank layers of the satin glaze blank, the fully polished glaze blank, and the high-transparency polished glaze blank are all 800mm×800mm in size. In the high-capacity kiln, the front edge of all blank layers along the conveying direction forms an angle 1 with the width direction of the high-capacity kiln, and the angle 1 is 5 to 11°.

7. The multi-glaze effect glazed tile co-firing process according to claim 4, characterized in that, The dimensions of the blank layers of the satin glaze blank, the fully polished glaze blank, and the high-transparency polished glaze blank are all 750mm×1500mm. In the high-capacity kiln, the short edge of all blank layers forms an angle II with the width direction of the high-capacity kiln, and the angle II is 7 to 13°.

8. The multi-glaze effect glazed tile co-firing process according to claim 1, characterized in that, According to the mass fractions, the raw materials of the low-expansion glaze include 36-40 parts of sodium feldspar, 9-11 parts of kaolin, 2-4 parts of quartz, 7-9 parts of nepheline, 10-14 parts of alumina, 10-14 parts of potassium feldspar, 14-16 parts of calcined clay, 1-3 parts of calcined talc, and 10-14 parts of zirconium silicate. According to the mass fractions, the raw materials of the medium-expansion glaze include 38-42 parts of sodium feldspar, 9-11 parts of kaolin, 4-6 parts of quartz, 9-11 parts of nepheline, 12-16 parts of alumina, 10-14 parts of potassium feldspar, 5-7 parts of calcined clay, 2-4 parts of calcined talc, and 10-14 parts of zirconium silicate. According to the mass fractions, the raw materials of the high-expansion glaze include 36-40 parts of albite, 9-11 parts of kaolin, 19-22 parts of quartz, 14-16 parts of nepheline, 14-16 parts of alumina, 1-3 parts of calcined talc, and 10-14 parts of zirconium silicate.

9. The multi-glaze effect glazed tile co-firing process according to claim 1, characterized in that, The application amount of the low-swell glaze, the satin glaze, the medium-swell glaze, the full-polished glaze, the high-swell glaze, and the high-transparency polished glaze is 420-480 g / m². 2 .

10. The multi-glaze effect glazed tile co-firing process according to claim 1, characterized in that, The inkjet volume of the color ink for the satin-glazed blank, the color ink for the fully polished glazed blank, and the color ink for the high-transparency polished glazed blank is all 4.8–9.6 g / m³. 2 .

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