A matt kiln glaze and a preparation method thereof

Abstract

The application discloses a kind of no light kiln glaze and preparation method thereof, belong to kiln glaze technical field, it includes the following mass parts of preparation raw materials: 38~45 parts of sunstone, 20~28 parts of calcite, 10~18 parts of kaolin, 6~14 parts of colemanite, 13~21 parts of strontium carbonate, 1~5 parts of nano zirconium oxide, 5~10 parts of composite colorant, 2~6 parts of microcrystalline control agent, 1~3.5 parts of fluxing regulator.Preparation method includes: S1.wet grinding, aging is obtained glaze pulp after preparation raw materials pretreatment;S2.high pressure glaze is applied to the surface of body and glazing is obtained;S3.glazing body is gradient firing, respectively, low-temperature preheating section, oxidation decomposition section, high-temperature melting section, microcrystalline precipitation section and cooling section.The application solves the technical problems of existing no light kiln glaze glaze surface dry and rough, kiln color single, glaze body matching poor, low yield, so that the glaze surface has kiln texture and high mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of kiln-transformed glaze technology, specifically a matte kiln-transformed glaze and its preparation method. Background Technology

[0002] Matte kiln-transformed glaze, as a ceramic decorative glaze that combines a soft texture and natural patterns, is widely used in architectural ceramics, art ceramics, and daily-use ceramics due to its velvety matte effect and unpredictable kiln-transformed colors. Especially in high-end decorative settings, its ability to create a tranquil and elegant visual experience has led to a continuous increase in market demand.

[0003] To achieve the dual goals of a matte finish and kiln-transformed texture, traditional matte glazes primarily employ two approaches: first, introducing opacifiers such as titanium dioxide and alumina into the glaze to utilize particle scattering and block light reflection; second, adjusting the SiO2 / Al2O3 ratio in the glaze to reduce the transparency of the glassy phase and create a matte texture. Existing kiln-transformed glazes largely rely on a single colorant, inducing color transitions by controlling the firing atmosphere to achieve valence state changes in the coloring ions. To address the issues of cracking and poor wear resistance in matte glazes, current technologies often employ methods such as increasing the amount of kaolin and introducing zinc oxide as a flux to adjust the coefficient of thermal expansion and improve mechanical properties. Some solutions attempt to add reinforcing phases such as nano-alumina and zirconium oxide to improve the glaze's toughness.

[0004] Despite some progress in the development of matte kiln-transformed glazes, the following core defects remain, limiting product performance and industrial applications: The contradiction between matte effect and glaze texture: Existing technologies relying on single opacifiers such as titanium dioxide and alumina to achieve matte finishes tend to result in a dry, rough glaze lacking a soft texture; existing kiln-transformed glazes mostly use single colorants, only capable of creating single color transitions such as yellowish-brown and reddish-brown, failing to achieve the rich effect of interwoven composite colors; existing technologies often optimize the coefficient of thermal expansion by adjusting the amount of kaolin or flux, but the poor matching between the glaze and the porcelain body leads to easy cracking and peeling of the glaze layer during firing, resulting in a poor yield. Summary of the Invention

[0005] To overcome the aforementioned technical problems, this invention provides a matte kiln-transformed glaze and its preparation method. This invention solves the technical problems of existing matte kiln-transformed glazes, such as dry glaze surface, monotonous kiln-transformed colors, poor glaze-body matching, and low yield, by introducing a strontium titanate and cerium oxide composite microcrystalline regulator, combined with a cobalt oxide and zirconium silicate composite colorant; and a five-stage gradient firing method.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0007] This invention discloses a matte kiln-transformed glaze, comprising the following raw materials in parts by weight: 35-45 parts of nepheline, 20-28 parts of calcite, 10-18 parts of kaolin, 6-14 parts of borocalcite, 13-21 parts of strontium carbonate, 1-5 parts of nano-zirconia, 5-10 parts of composite colorant, 2-6 parts of microcrystalline regulator, and 1-3.5 parts of fluxing agent.

[0008] Preferably, the matte kiln-transformed glaze comprises the following raw materials in parts by weight: 38-42 parts macadamite, 22-26 parts calcite, 12-16 parts kaolinite, 8-12 parts borocalcite, 15-19 parts strontium carbonate, 2-4 parts nano-zirconia, 6-9 parts composite colorant, 3-5 parts microcrystalline regulator, and 1.5-3 parts fluxing regulator.

[0009] According to some embodiments of the present invention, the composite colorant is a mixture of cobalt oxide and zirconium silicate; the mass ratio of cobalt oxide to zirconium silicate is 2~5:1, preferably 2.5~4:1.

[0010] Cobalt oxide is the core colorant for cool tones; during the high-temperature melting process, Co... 2+ It dissolves uniformly into the glaze glass phase. Adding cobalt oxide alone will produce a deep blue color, but when combined with zirconium silicate, Co... 2+ The color of cobalt oxide is neutralized by the opacifying effect of zirconium silicate, ultimately resulting in a dark gray. Zirconium silicate is a high-temperature stable opacifier that does not participate in valence state changes. Its micron-sized particles scatter light, reducing the transparency of the glaze and preventing cobalt oxide from becoming too dark. This also makes the gray more uniform and softer, matching the matte texture. The mass ratio of cobalt oxide to zirconium silicate directly affects the gray level.

[0011] According to some embodiments of the present invention, the microcrystalline regulator is a compound of strontium titanate and cerium oxide; the weight ratio of strontium titanate to cerium oxide is 2~5:1, preferably 3~4:1.

[0012] According to some embodiments of the present invention, the strontium titanate has a particle size of 1~3 μm; the cerium oxide has a particle size of 500~800 nm.

[0013] Cerium oxide, acting as a heterogeneous nucleation site, can first form micro-nuclei in the high-temperature melting section, providing attachment sites for the growth of strontium titanate. Strontium titanate grows directionally around the cerium oxide nuclei, forming a continuous needle-like interwoven structure. These interwoven structures constitute the physical framework of the white texture; when illuminated, the needle-like microcrystals scatter the light, resulting in a white appearance. The weight ratio of strontium titanate to cerium oxide determines the framework density.

[0014] According to some embodiments of the present invention, the fluxing agent is a mixture of zinc oxide and calcium fluoride; the weight ratio of zinc oxide to calcium fluoride is 1.5 to 4:1.

[0015] According to some embodiments of the present invention, the particle size of the nano-zirconia is 50~100nm.

[0016] This invention also discloses a method for preparing matte kiln-transformed glaze, comprising the following steps: S1. The pretreated raw materials are wet-milled and aged to obtain a glaze slurry; S2. Apply glaze to the surface of the unglazed body using high-pressure spraying to obtain a glazed body; S3. The glazed body is subjected to gradient firing, which includes a low-temperature preheating section, an oxidation decomposition section, a high-temperature melting section, a microcrystal precipitation section, and a cooling section.

[0017] The pretreatment involves crushing leucite, calcite, and kaolin to a particle size ≤5mm and drying them at 105~110℃ for 4~6h; grinding borocalcite to a particle size ≤1mm; and drying strontium carbonate, nano-zirconia, composite colorant, microcrystal regulator, and fluxing agent for later use. According to some embodiments of the present invention, the mass ratio of feed material:balls:water in the wet milling is 1:2.5~3:1.2~1.5.

[0018] According to some embodiments of the present invention, the wet milling is passed through a 200-300 mesh sieve, for example, a 250 mesh sieve.

[0019] According to some embodiments of the present invention, 0.1-0.2 wt% sodium carboxymethyl cellulose is added before aging to adjust the specific gravity of the glaze slurry to 1.55-1.65 g / cm³. 3 .

[0020] According to some embodiments of the present invention, the aging process is carried out at 25-40°C for 10-16 hours.

[0021] According to some embodiments of the present invention, the pressure of the high-pressure glazing is 0.3~0.5MPa, and the high-pressure glazing distance is 25~35cm.

[0022] According to some embodiments of the present invention, the high-pressure glazing is performed in two stages. After the first glazing, the glaze is dried at 60-80°C for 30-40 minutes. After the second glazing, the glaze thickness is controlled to be 0.8-1.2 mm.

[0023] According to some embodiments of the present invention, the low-temperature preheating section is maintained at 300~350°C for 30~40 minutes.

[0024] According to some embodiments of the present invention, the oxidative decomposition section is held at 800~850°C for 20~50 min, during which air is introduced and the oxygen content is maintained at 8~10 vol.

[0025] According to some embodiments of the present invention, the high-temperature melting section is held at 1260~1280°C for 60~90 minutes, and the process is carried out in a weak reducing atmosphere.

[0026] According to some embodiments of the present invention, the microcrystal precipitation section is cooled to 950~980℃ and then held at that temperature for 40~60 minutes to maintain a weak reducing atmosphere.

[0027] According to some embodiments of the present invention, the cooling section is cooled to room temperature (20~25°C) along with the furnace, and nitrogen gas is introduced for protection during this process.

[0028] According to some embodiments of the present invention, the weakly reducing atmosphere contains 1.5 to 2.5 vol% carbon monoxide and 0.5 to 1 vol% hydrogen.

[0029] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0030] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a composite colorant that utilizes the cool-toned coloring properties of cobalt oxide and the opacifying effect of zirconium silicate to neutralize excessively dark colors, achieving a uniform and soft matte dark gray base. The microcrystalline regulator uses cerium oxide as heterogeneous nucleation sites and strontium titanate as needle-like microcrystalline framework to form an interwoven structure, constructing a natural kiln-transformed texture.

[0031] This invention employs a five-stage firing curve: low-temperature preheating, oxidation decomposition, high-temperature melting, microcrystal precipitation, and cooling. The oxidation decomposition stage promotes the dissolution of colorants and the decomposition of organic matter; the high-temperature melting stage ensures that the glaze is fully melted, providing conditions for microcrystal precipitation and the transformation of the valence state of coloring ions; the microcrystal precipitation stage precisely controls the microcrystal growth rate to avoid agglomeration; and the cooling stage prevents glaze oxidation, ensuring a matte finish and texture stability.

[0032] The final matte kiln-transformed glaze exhibits a deep gray matte base, free from dryness and roughness, with clear and natural white flow lines. The gloss level of the matte kiln-transformed glaze is ≤30Gu, with a soft texture, neither too bright nor too dark; it also possesses excellent mechanical properties, with a Mohs hardness of 6.0~7.0, resulting in ceramic products with strong wear resistance and impact resistance. The yield rate is as high as 89% or more, reaching over 90% in some optimized solutions, significantly reducing industrial cost losses. Attached Figure Description

[0033] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0034] Figure 1 This is a visual image of the matte kiln-transformed glaze of Example 1.

[0035] Figure 2 This is a visual image of the matte kiln-transformed glaze in Example 2.

[0036] Figure 3 This is a visual image of the matte kiln-transformed glaze in Example 3.

[0037] Figure 4 This is a visual image of the matte kiln-transformed glaze in Example 4.

[0038] Figure 5 The image shows the matte kiln-transformed glaze appearance of Comparative Example 1. Detailed Implementation

[0039] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0040] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0041] The "range" disclosed in this invention is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be combined arbitrarily; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is understood that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this invention, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein; "0-5" is merely a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer greater than or equal to 2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0042] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0043] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0044] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0045] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0046] Unless otherwise specified, the term "or" is inclusive in this invention. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0047] Example 1 The matte kiln-transformed glaze of this embodiment comprises the following raw materials in parts by weight: 40 parts nepheline, 24 parts calcite, 14 parts kaolin, 10 parts borocalcite, 17 parts strontium carbonate, 3 parts nano-zirconia (D50 of 85nm), 7.5 parts composite colorant (5.62 parts cobalt oxide, 1.88 parts zirconium silicate), 4 parts microcrystal regulator (2.67 parts strontium titanate, 1.33 parts cerium oxide), and 2.25 parts fluxing agent (1.35 parts zinc oxide, 0.9 parts calcium fluoride). In the composite colorant, the mass ratio of cobalt oxide to zirconium silicate is 3:1; in the microcrystalline regulator, the mass ratio of strontium titanate to cerium oxide is 2:1; and in the fluxing regulator, the mass ratio of zinc oxide to calcium fluoride is 1.5:1.

[0048] The preparation method of the matte kiln-transformed glaze in this embodiment is as follows: S1. Maize, calcite, and kaolin are crushed to a particle size ≤5mm and dried; borocalcite is ground to a particle size ≤1mm using a universal pulverizer and stored in a sealed container to prevent moisture absorption; strontium carbonate, nano-zirconia, composite colorant, microcrystalline regulator, and fluxing agent are placed in a drying oven and dried at 60℃ for 2 hours to ensure a moisture content ≤0.5% for later use. The materials were added to the ball mill jar according to the above proportions, with the raw materials, high-zirconium pebbles, and water added in a material:ball:water mass ratio of 1:2.8:1.3. The ball mill was run at 135 r / min for 24 h. After ball milling, the mixture was filtered through a 250-mesh vibrating sieve. 0.15 wt% sodium carboxymethyl cellulose was added to the sieved base glaze slurry, and the mixture was stirred in a high-speed disperser (800 r / min) for 35 min. The specific gravity of the glaze slurry was measured using a hydrometer and adjusted to 1.60 g / cm³ by adding a small amount of deionized water. 3 ; The prepared glaze slurry was transferred to a stainless steel aging tank, sealed, and placed in an environment of 28°C and 65% relative humidity for 14 hours. During this period, it was stirred for 5 minutes every 4 hours to prevent stratification. The resulting glaze slurry was obtained.

[0049] S2. Apply glaze slurry to the surface of the unglazed body using high-pressure spraying; First glazing: spraying pressure 0.4MPa, spraying distance 30cm, spraying time 18s, ensuring a uniform thin glaze layer on the surface of the unglazed body; Place the unglazed body after the first glazing into a drying oven and dry at 70℃ for 35min; Second glazing: Maintain the same spraying pressure and distance as the first time, spraying time 22s, and use a coating thickness gauge to check the glaze layer thickness after glazing, controlling it to be within 1.0mm, thus obtaining the glazed body; S3. The glazed body is then subjected to gradient firing, as follows: Low-temperature preheating section: 320℃ and hold for 30 minutes; Oxidative decomposition section: Hold at 800℃ for 35 minutes. Air is introduced during this process, and the oxygen content is maintained at 8~10 vol%. After the process, nitrogen is introduced to replace the gas. High-temperature melting section: The process is carried out at 1270℃ for 75 minutes in a weak reducing atmosphere; the weak reducing atmosphere contains 2.0 vol% carbon monoxide, 0.8 vol% hydrogen, and the balance is nitrogen. Microcrystal precipitation section: After cooling to 960℃, hold for 50 min to maintain a weak reducing atmosphere; the weak reducing atmosphere contains 2.0 vol% carbon monoxide, 0.8 vol% hydrogen, and the balance nitrogen. Cooling section: The furnace cools down to room temperature, and nitrogen gas is introduced for protection during this process.

[0050] The matte kiln-transformed glaze appearance of this embodiment is as follows: Figure 1 The glaze has a matte dark gray base with evenly distributed light white flowing patterns. The patterns are clear but the transitions are natural.

[0051] Example 2 The difference between this embodiment and Embodiment 1 is as follows: The matte kiln-transformed glaze of this embodiment comprises the following raw materials in parts by weight: 40 parts nepheline, 24 parts calcite, 14 parts kaolin, 10 parts borocalcite, 17 parts strontium carbonate, 3 parts nano-zirconia, 7.5 parts composite colorant, 6 parts microcrystalline regulator (3 parts strontium titanate, 3 parts cerium oxide), and 2.25 parts fluxing agent; the mass ratio of strontium titanate to cerium oxide in the microcrystalline regulator is 1:1. Other raw materials, steps, and parameters are the same as in Example 1; The matte kiln-transformed glaze appearance of this embodiment is as follows: Figure 2 The glaze has a matte dark gray base with a wide white flow-like texture. The texture boundaries are clear but the transition is abrupt. There are some localized texture stacking patches. This is because the high proportion of cerium oxide in the microcrystal regulator leads to an excessive and dense distribution of heterogeneous nucleation points. The growth space of strontium titanate needle-like microcrystals is limited, and the microcrystals of adjacent nuclei are squeezed and agglomerated, eventually forming a wide white texture with an unnatural transition.

[0052] Example 3 The difference between this embodiment and Embodiment 1 is as follows: The matte kiln-transformed glaze of this embodiment includes the following raw materials in parts by weight: 40 parts nepheline, 24 parts calcite, 14 parts kaolin, 10 parts borocalcite, 17 parts strontium carbonate, 3 parts nano-zirconia, 7.5 parts composite colorant, 3 parts microcrystalline regulator (3 parts cerium oxide), and 2.25 parts fluxing regulator. The other raw materials, steps and parameters are the same as in Example 1.

[0053] The matte kiln-transformed glaze appearance of this embodiment is shown in the image below. Figure 3 The glaze has a uniform light gray base with very faint texture and no obvious white texture. This is because the microcrystalline regulator contains only cerium oxide and lacks strontium titanate, the core skeletal component that forms the white texture. Although cerium oxide can provide heterogeneous nucleation sites at high temperatures, it cannot grow in a directional manner to form a needle-like interwoven structure. Without a physical framework to support light scattering, there is no obvious white texture.

[0054] Example 4 The difference between this embodiment and Embodiment 1 is as follows: The matte kiln-transformed glaze of this embodiment comprises the following raw materials in parts by weight: 40 parts mahogany, 24 parts calcite, 14 parts kaolinite, 10 parts borocalcite, 17 parts strontium carbonate, 3 parts nano-zirconia, 7.5 parts composite colorant (6 parts cobalt oxide and 1.5 parts iron oxide red), 6 parts microcrystal regulator (5 parts strontium titanate and 1 part cerium oxide), and 2.25 parts fluxing agent; the mass ratio of strontium titanate to cerium oxide in the microcrystal regulator is 5:1. The other raw materials, steps and parameters are the same as in Example 1.

[0055] The matte kiln-transformed glaze appearance of this embodiment is shown in the image below. Figure 4 The glaze has a yellowish-brown and gray mottled texture, which is due to the addition of iron oxide red as a colorant, resulting in a yellowish glaze color.

[0056] Comparative Example 1 The difference between this embodiment and Embodiment 1 is as follows: The matte kiln-transformed glaze of this embodiment comprises the following raw materials in parts by weight: 40 parts nepheline, 24 parts calcite, 14 parts kaolin, 10 parts borate, 17 parts strontium carbonate, 3 parts nano-zirconia, 7.5 parts composite colorant, 1.5 parts microcrystalline regulator (0.75 parts strontium titanate, 0.75 parts cerium oxide), and 5 parts fluxing regulator (3.0 parts zinc oxide, 2.0 parts calcium fluoride). In the microcrystalline control agent, the mass ratio of strontium titanate to cerium oxide is 1:1; in the fluxing control agent, the mass ratio of zinc oxide to calcium fluoride is 3:2. In the S3 process, the high-temperature melting section is held at 1300℃ for 120 minutes. The matte kiln-transformed glaze appearance of this comparative example is shown in the image below. Figure 5 The glaze has a light gray base and a whitish, blurry texture with a glossy finish. This is because the excessive flux in this embodiment significantly reduces the melting temperature of the glaze, resulting in abnormally increased fluidity. Meanwhile, the insufficient nucleation sites and microcrystalline framework of the microcrystalline regulator cannot constrain the flow of the glaze. Over-melting causes zirconium silicate to diffuse excessively with the glaze and cannot be oriented to adsorb on the microcrystalline framework. Ultimately, it fuses with the light gray base, forming a whitish, blurry texture.

[0057] Test case The matte kiln-transformed glazes prepared in the above embodiments and comparative examples were subjected to the following tests, and the test results are shown in Table 1. Gloss testing shall be performed in accordance with GB / T 13891; The Mohs hardness test shall be performed in accordance with GB / T 9966.1; The yield rate is calculated by selecting 100 samples from each batch in the above examples and comparative examples, and counting the percentage of qualified products that are free of cracks, pinholes, glaze shrinkage, and have normal kiln transformation textures.

[0058]

[0059] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this invention. It should be understood that the above descriptions are merely specific embodiments of this invention and are not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A matte kiln-transformed glaze, characterized in that, The raw materials include the following parts by weight: 35-45 parts macadamite, 20-28 parts calcite, 10-18 parts kaolinite, 6-14 parts borocalcite, 13-21 parts strontium carbonate, 1-5 parts nano-zirconia, 5-10 parts composite colorant, 2-6 parts microcrystal regulator, and 1-3.5 parts fluxing agent.

2. The matte kiln-transformed glaze as described in claim 1, characterized in that, The composite colorant is a mixture of cobalt oxide and zirconium silicate; And / or, the mass ratio of cobalt oxide to zirconium silicate is 2~5:1, preferably 2.5~4:

1.

3. The matte kiln-transformed glaze as described in claim 1, characterized in that, The microcrystal regulator is a compound of strontium titanate and cerium oxide; And / or, the weight ratio of strontium titanate to cerium oxide is 2~5:1, preferably 3~4:1; And / or, the strontium titanate has a particle size of 1~3μm; the cerium oxide has a particle size of 500~800nm.

4. The matte kiln-transformed glaze as described in claim 1, characterized in that, The fluxing agent is a mixture of zinc oxide and calcium fluoride; And / or, the weight ratio of zinc oxide to calcium fluoride is 1.5 to 4:

1.

5. The matte kiln-transformed glaze as described in claim 1, characterized in that, The particle size of the nano-zirconia is 50~100nm.

6. The method for preparing matte kiln-transformed glaze according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. The pretreated raw materials are wet-milled and aged to obtain a glaze slurry; S2. Apply glaze to the surface of the unglazed body using high-pressure spraying to obtain a glazed body; S3. The glazed body is subjected to gradient firing, which includes a low-temperature preheating section, an oxidation decomposition section, a high-temperature melting section, a microcrystal precipitation section, and a cooling section.

7. The method for preparing matte kiln-transformed glaze as described in claim 6, characterized in that, The pretreatment involves crushing leucite, calcite, and kaolin to a particle size ≤5mm and drying them at 105~110℃ for 4~6h; grinding borocalcite to a particle size ≤1mm; and drying strontium carbonate, nano-zirconia, composite colorant, microcrystal regulator, and fluxing agent for later use. And / or, the mass ratio of material:balls:water in the wet milling is 1:2.5~3:1.2~1.5; And / or, the wet milling is passed through a 200-300 mesh sieve; And / or, before aging, add 0.1~0.2wt% sodium carboxymethyl cellulose to adjust the specific gravity of the glaze slurry to 1.55~1.65 g / cm³. 3 ; And / or, the aging is carried out at 25~40℃ for 10~16h.

8. The method for preparing matte kiln-transformed glaze as described in claim 6, characterized in that, The pressure of the high-pressure glazing is 0.3~0.5MPa, and the high-pressure glazing distance is 25~35cm; And / or, the high-pressure glazing is performed in two stages. After the first glazing, the glaze is dried at 60-80℃ for 30-40 minutes. After the second glazing, the glaze thickness is controlled to be 0.8-1.2 mm.

9. The method for preparing matte kiln-transformed glaze as described in claim 6, characterized in that, The low-temperature preheating section is maintained at 300~350℃ for 30~40 minutes. And / or, the oxidative decomposition section is carried out at 800~850℃ for 20~50 min, during which air is introduced and the oxygen content is maintained at 8~10 vol%. And / or, the high-temperature melting section is held at 1260~1280℃ for 60~90 min, and this process is carried out in a weak reducing atmosphere; And / or, the microcrystal precipitation section is cooled to 950~980℃ and then held at that temperature for 40~60 minutes to maintain a weak reducing atmosphere; And / or, the cooling section is cooled to room temperature along with the furnace, a process protected by nitrogen gas.

10. The method for preparing matte kiln-transformed glaze as described in claim 9, characterized in that, The weakly reducing atmosphere contains 1.5-2.5 vol% carbon monoxide and 0.5-1 vol% hydrogen.

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