A Chinese red color glaze and a preparation method thereof
By using pre-fired copper aluminum silicate precursors and gradient firing process, the problem of unstable color development caused by fluctuations in the valence state of copper was solved, achieving uniform color development and high yield of Chinese red glaze, and avoiding glaze defects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JINGDEZHEN CHENGDEXUAN PORCELAIN CO LTD
- Filing Date
- 2026-05-27
- Publication Date
- 2026-06-23
AI Technical Summary
In the preparation of Chinese red glaze, the fluctuation of the valence state of copper in existing technologies leads to unstable color development, low yield, and problems such as bubbles, cracking, and glaze flow, making it difficult to achieve stable color development of high-temperature red glaze.
By mixing and pre-calcining a copper source with kaolin and sucrose to form a copper aluminum silicate precursor, a carbon film is coated on the precursor to control the release of copper ions. A gradient calcination process is then used to combine tin oxide and zircon to form composite microcrystals, which block Cu+ migration and ensure uniform and stable color development.
It achieves uniform conversion and stable color development of copper ions, improves yield, avoids glaze defects, ensures the uniformity and stability of the glaze, and has high color purity and yield.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of ceramic glaze technology, and relates to a Chinese red colored glaze and its preparation method. Background Technology
[0002] Chinese red glaze has a long history and is characterized by its rich, deep, and dignified color. Among the many colorful porcelains throughout history, high-temperature red glaze porcelain is uniquely rare. This is because the red glaze uses copper as its coloring core, requiring a reducing atmosphere to achieve the desired color development of monovalent copper ions (Cu). + The color can only be achieved through transformation. Because the firing conditions are difficult to match precisely, firing is extremely difficult. It is said that "one in a thousand kilns is a treasure, and nine out of ten kilns fail to produce a masterpiece." Therefore, firing bright red glaze has become an age-old problem in world history and the dream of skilled craftsmen throughout the ages.
[0003] Traditional methods for preparing red glaze typically involve directly adding copper oxide or copper carbonate as a colorant. However, copper is prone to valence fluctuations during glaze preparation, application, and heating, affecting the color development. Furthermore, variations in the reduction atmosphere's initiation temperature, duration, and control during firing can lead to incomplete or excessive reduction of copper valence, resulting in poor color stability and low yield. Additionally, the common practice of multiple glaze layers can cause bubbles, cracking, and glaze flow, further impacting the yield. Therefore, developing a Chinese red glaze that improves color stability, increases firing process tolerance, and achieves a high yield has significant industrial application value. Summary of the Invention
[0004] To address the aforementioned shortcomings, this invention provides a Chinese red glaze and its preparation method. The Chinese red glaze exhibits uniform color development, pure and stable color, and a high yield.
[0005] The first objective of this invention is to provide a method for preparing Chinese red colored glaze, comprising the following steps: (1) Glaze preparation: The raw materials are mixed according to the following weight parts: feldspar 38-40 parts, calcite 10-12 parts, quartz 20-23 parts, kaolin 12-15 parts, copper source precursor 2.5-3.5 parts, zinc oxide 2-4 parts, iron oxide 0.08-0.12 parts, tin oxide 2.5-3.5 parts, and zircon 3.5-4.5 parts. The mixture is then ball-milled to obtain the glaze. The copper source precursor is prepared by pre-firing nano-copper oxide, kaolin, and sucrose under an inert atmosphere. Specifically, nano-copper oxide, kaolin, and sucrose are mixed in a mass ratio of 0.8-1.2:2:0.5. After mixing, the mixture is dry ball-milled for 2-3 hours, then heated to 800±20℃ under an inert atmosphere and held for 1-3 hours. After sintering, it is naturally cooled, ground, and set aside. In this step, nano-sized copper oxide, kaolin, and sucrose are pre-calcined at 800℃. The layered structure of kaolin can adsorb and fix copper ions at defect sites, forming a stable copper aluminum silicate precursor, which is then coated with a carbon film. This prevents the release of active copper ions at low temperatures. During subsequent calcination, when the temperature reaches 600-800℃, the carbon film is slowly oxidized, forming a localized micro-reducing atmosphere. When the temperature reaches above 750℃, copper begins to oxidize into Cu. + The conversion not only reduces the excessive dependence on the external reducing atmosphere, but also allows for concentrated release, resulting in synchronous and uniform color development. Specifically, the inert atmosphere is a nitrogen, argon, or helium atmosphere, providing an oxygen-free and stable environment for sintering.
[0006] (2) Glazing: Apply the glaze to the unglazed body in one go and let it air dry naturally; (3) Gradient firing: The glazed body is transferred into the firing furnace and fired at progressively higher temperatures, specifically: a. Low-temperature pre-calcination section: The temperature is increased from room temperature to 600℃ in an oxidizing atmosphere at a heating rate of 5-6℃ / min; b. Medium-temperature reduction start-up section: The temperature is raised from 600℃ to 980℃ at a heating rate of 3-4℃ / min, and a reducing atmosphere is introduced at 750℃; c. High-temperature color development section: Raise the temperature from 980℃ to 1270-1330℃ at a heating rate of 2-3℃ / min, introduce a strong reducing atmosphere, and hold for 30-40min. d. Cooling section: After cooling to 1100℃, the reducing gas is shut off, and the mixture is cooled to room temperature in a weak oxidizing atmosphere.
[0007] This invention pre-fires a copper source mixed with kaolin and sucrose, anchoring copper ions in the lattice of metakaolinite derived from kaolin. Simultaneously, a thin carbon film is coated on the surface, effectively preventing valence fluctuations of copper during glaze preparation and initial heating, avoiding early blackening, and improving the uniformity and stability of color development. When the subsequent firing temperature rises to the carbon film oxidation temperature, the precursor lattice begins to soften and react with the glaze melt, allowing copper ions to be released in a concentrated manner within a narrow temperature window, ensuring synchronous color development, more uniform color, and improved yield. Furthermore, this invention optimizes the raw material ratio, using feldspar as the main raw material as the base of the glaze to ensure the fluidity and mechanical strength of the glaze layer. A slightly higher proportion of potassium feldspar ensures both spreadability and prevents glaze run-through. Adding appropriate amounts of calcite introduces calcium oxide, providing a flux while also improving the hardness and chemical stability of the glaze surface. Adding quartz introduces SiO2 as a glaze layer skeleton component, balancing the fluidity brought by the flux, preventing glaze run-through, and improving the wear resistance of the glaze surface. Adding kaolin introduces Al2O3 and improves the suspension and adhesion of the glaze slurry. The added zinc oxide acts as a flux, reducing the high-temperature viscosity of the glaze, promoting a smooth and stable glaze surface, and also improving the gloss. The added trace amounts of iron oxide can fine-tune the red hue, making it deeper, and also promotes the uniform precipitation of tin-zirconium microcrystals. The added tin oxide forms composite microcrystals with zircon, exhibiting strong inertness at high temperatures and not reacting with copper ions, physically blocking Cu. + Migration also enhances reflection and increases brightness. Simultaneously, the copper source precursor is ball-milled into a glaze and applied to the unglazed body. A gradient reduction firing process is employed: first, pre-firing at a low temperature removes moisture and organic matter without damaging the structure of the copper source precursor, preventing the copper source from being released; then, reduction is initiated in the mid-temperature range. When the carbon film is essentially depleted at 750℃ and above, a micro-reducing atmosphere is formed, the crystal lattice begins to soften, and copper ions are released. Simultaneously, reducing gas is introduced to establish a weakly reducing atmosphere, ensuring that the copper ions are converted into Cu during release. + Furthermore, high temperature and a strong reducing atmosphere are used to ensure that Cu is present in the glaze melt. + The primary component exhibits color development, and as the temperature increases, tin-zirconium composite microcrystals precipitate and form a three-dimensional network, which can block Cu. + The migration of the crystals forms a stable red color; finally, the temperature is allowed to drop naturally for a period of time before the cooling rate is accelerated to prevent the high tin zirconium composite microcrystals from becoming too coarse and affecting the transparency of the glaze. The resulting product has a bright and uniform red color and a high yield.
[0008] Preferably, in step (1) of the above technical solution, the purity of the nano-copper oxide is ≥99%, D 50 ≤50nm; the D of the kaolin 90 ≤10μm; the heating rate to 800±20℃ is 4-5℃ / min.
[0009] Preferably, in step (1) of the above technical solution, the particle size D of the copper source precursor is... 90 ≤10μm.
[0010] Preferably, in step (1) of the above technical solution, the mass ratio of raw materials:balls:water is 1:1.5-2:0.7-0.8; the ball milling speed is 500-800 rpm; the ball milling is carried out until the fineness is ≤0.05% on a 10,000-mesh sieve, and the glaze concentration is adjusted to a Baumé degree of 45-50. By controlling the glaze composition ratio and Baumé degree, this invention can meet the color depth requirements with only one glazing application, avoiding interlayer defects caused by multiple glazing applications.
[0011] Preferably, in step (2) of the above technical solution, the thickness of the glaze applied in one application is 0.28-0.35 mm.
[0012] Preferably, in step (3) of the above technical solution, the oxygen content in the oxidizing atmosphere of the low-temperature pre-burning section is 8-12%; the reducing atmosphere of the medium-temperature reduction start-up section is a mixture of carbon monoxide and nitrogen in a volume ratio of 1:10, and the oxygen content is less than 1.8%.
[0013] Preferably, in step (3) of the above technical solution, the strong reducing atmosphere of the high-temperature color development section is a mixture of carbon monoxide and nitrogen in a volume ratio of 1:8, and the oxygen content is less than 0.6%; the oxygen content in the weak oxidizing atmosphere of the cooling section is 3-5%.
[0014] The present invention also provides a Chinese red glaze prepared by the above preparation method.
[0015] Advantages compared to existing technologies: This invention prepares a copper source precursor by pre-mixing the copper source with kaolin and sucrose, which can effectively prevent valence state fluctuations of copper during glaze preparation and initial heating stages, avoid early blackening, and improve the uniformity and stability of color development. In the subsequent firing process, gradient heating is adopted to control the heating rate and reaction atmosphere by utilizing the different reactions at different temperatures, effectively controlling the conversion of copper ions, resulting in synchronous and uniform color development, and stronger adaptability to kiln atmosphere fluctuations.
[0016] This invention, through the introduction of tin oxide and zircon, forms a physical barrier during the firing process, preventing Cu from being sintered. + The migration of color ensures that the red color is evenly fixed in the glaze layer after development, forming a stable and uniform color, which effectively improves the yield. Detailed Implementation
[0017] The above-described technical features of the present invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. However, the present invention is not limited to these embodiments, nor are these embodiments limited in any way.
[0018] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the formulations involved in the following examples are all commercially available products that can be purchased from the market.
[0019] The present invention will be further described in detail below with reference to embodiments: Example 1 Preparation of copper source precursor: First, nano-copper oxide (purity ≥99%, D) is prepared. 50 ≤50nm), kaolin (D 90 ≤10μm particles and sucrose were mixed at a mass ratio of 1:2:0.5 and then dry-ball-milled for 2.5h. The mixture was then heated to 800±20℃ at a rate of 4.5℃ / min under a nitrogen atmosphere and held at that temperature for 2h. After sintering, the mixture was allowed to cool naturally and then ground to a particle size D. 90 ≤10μm, for future use.
[0020] Example 2 Preparation of copper source precursor: First, nano-copper oxide (purity ≥99%, D) is prepared. 50 ≤50nm), kaolin (D 90 ≤10μm) and sucrose were mixed at a mass ratio of 0.8:2:0.5 and then dry-ball-milled for 2 hours. Then, under an argon atmosphere, the mixture was heated to 800±20℃ at a rate of 4℃ / min and held at that temperature for 3 hours. After sintering, it was allowed to cool naturally and then ground to a particle size D. 90 ≤10μm, for future use.
[0021] Example 3 Preparation of copper source precursor: First, nano-copper oxide (purity ≥99%, D) is prepared. 50 ≤50nm), kaolin (D 90 ≤10μm) and sucrose were mixed at a mass ratio of 1.2:2:0.5 and then dry-ball-milled for 3 hours. The mixture was then heated to 800±20℃ at a rate of 5℃ / min under a helium atmosphere and held for 1 hour. After sintering, it was allowed to cool naturally and then ground to a particle size D. 90 ≤10μm, for future use.
[0022] Example 4 A method for preparing a Chinese red colored glaze includes the following steps: (1) Glaze preparation: First, mix 38 parts of feldspar, 10 parts of calcite, 20 parts of quartz, 12 parts of kaolin, 2.5 parts of copper source precursor prepared in Example 1, 2 parts of zinc oxide, 0.08 parts of iron oxide, 2.5 parts of tin oxide, and 3.5 parts of zircon. Then, add the mixture to a ball mill for ball milling (the mass ratio of raw materials: balls: water is 1:2:0.8) at a speed of 500 rpm. Ball mill until the fineness is ≤0.05% on a 10,000 mesh sieve. Adjust the glaze concentration to a Baume degree between 45 and 50 to obtain the glaze. (2) Glazing: Apply the glaze to the unglazed body in one go, with a thickness of 0.28-0.35mm, and let it air dry naturally; (3) Gradient firing: The glazed body is transferred into the firing furnace and fired at progressively higher temperatures, specifically: a. Low-temperature pre-calcination section: The temperature is increased from room temperature to 600℃ at a rate of 5℃ / min in an oxidizing atmosphere (oxygen content 8%). b. Medium-temperature reduction start-up section: The temperature is raised from 600℃ to 980℃ at a heating rate of 3℃ / min, and a reducing atmosphere (carbon monoxide to nitrogen volume ratio = 1:10, and oxygen content less than 1.8%) is introduced at 750℃. c. High-temperature color development section: The temperature is raised from 980℃ to 1270℃ at a heating rate of 2℃ / min, and then raised to 1330℃. A strong reducing atmosphere is introduced (the volume ratio of carbon monoxide to nitrogen is 1:8, and the oxygen content is less than 0.6%), and the temperature is maintained for 30 min. d. Cooling section: After cooling to 1100℃, the reducing gas is shut off, and the room temperature is cooled in a weak oxidizing atmosphere (oxygen content 4%).
[0023] Example 5 A method for preparing a Chinese red colored glaze includes the following steps: (1) Glaze preparation: First, mix 39 parts of feldspar, 11 parts of calcite, 22 parts of quartz, 13 parts of kaolin, 3 parts of copper source precursor prepared in Example 1, 3 parts of zinc oxide, 0.1 parts of iron oxide, 3 parts of tin oxide, and 4 parts of zircon. Then, add the mixture to a ball mill for ball milling (the mass ratio of raw materials: balls: water is 1:1.5:0.7) at a speed of 600 rpm. The ball milling is carried out until the fineness is ≤0.05% on a 10,000 mesh sieve. The glaze concentration is adjusted to a Baume degree between 45 and 50 to obtain the glaze. (2) Glazing: Apply the glaze to the unglazed body in one go, with a thickness of 0.28-0.35mm, and let it air dry naturally; (3) Gradient firing: The glazed body is transferred into the firing furnace and fired at progressively higher temperatures, specifically: a. Low-temperature pre-calcination section: The temperature is increased from room temperature to 600℃ at a heating rate of 5.5℃ / min in an oxidizing atmosphere (oxygen content 10%). b. Medium-temperature reduction start-up section: The temperature is raised from 600℃ to 980℃ at a heating rate of 3.5℃ / min, and a reducing atmosphere (carbon monoxide to nitrogen volume ratio = 1:10, and oxygen content less than 1.8%) is introduced at 750℃. c. High-temperature color development section: The temperature is raised from 980℃ to 1270℃ at a heating rate of 2.5℃ / min, and then raised to 1330℃. A strong reducing atmosphere is introduced (the volume ratio of carbon monoxide to nitrogen is 1:8, and the oxygen content is less than 0.6%), and the temperature is maintained for 35 min. d. Cooling section: After cooling to 1100℃, the reducing gas is shut off, and the room temperature is cooled in a weak oxidizing atmosphere (oxygen content 3%).
[0024] Example 6 A method for preparing a Chinese red colored glaze includes the following steps: (1) Glaze preparation: First, mix 40 parts feldspar, 12 parts calcite, 23 parts quartz, 15 parts kaolin, 3.5 parts copper source precursor prepared in Example 1, 4 parts zinc oxide, 0.12 parts iron oxide, 3.5 parts tin oxide, and 4.5 parts zircon. Then, add the mixture to a ball mill for ball milling (the mass ratio of raw materials: balls: water is 1:1.8:0.75) at a speed of 800 rpm. The mixture is ball milled until the fineness is ≤0.05% on a 10,000 mesh sieve. The glaze concentration is then adjusted to a Baume degree between 45 and 50 to obtain the glaze. (2) Glazing: Apply the glaze to the unglazed body in one go, with a thickness of 0.28-0.35mm, and let it air dry naturally; (3) Gradient firing: The glazed body is transferred into the firing furnace and fired at progressively higher temperatures, specifically: a. Low-temperature pre-calcination section: The temperature is increased from room temperature to 600℃ at a rate of 6℃ / min in an oxidizing atmosphere (oxygen content 12%). b. Medium-temperature reduction start-up section: The temperature is raised from 600℃ to 980℃ at a heating rate of 4℃ / min, and a reducing atmosphere (carbon monoxide to nitrogen volume ratio = 1:10, and oxygen content less than 1.8%) is introduced at 750℃. c. High-temperature color development section: The temperature is raised from 980℃ to 1270℃ at a heating rate of 3℃ / min, and then raised to 1330℃. A strong reducing atmosphere is introduced (the volume ratio of carbon monoxide to nitrogen is 1:8, and the oxygen content is less than 0.6%), and the temperature is maintained for 40 min. d. Cooling section: After cooling to 1100℃, the reducing gas is shut off, and the room temperature is cooled in a weak oxidizing atmosphere (oxygen content 5%).
[0025] Comparative Example 1 A method for preparing Chinese red glaze differs from Example 4 in that the copper source precursor in the glaze is replaced with copper oxide, while the rest is the same as in Example 4.
[0026] Comparative Example 2 A method for preparing a Chinese red glaze differs from Example 4 in that tin oxide and zircon are added to the glaze, while the rest is the same as in Example 4.
[0027] Comparative Example 3 The method for preparing a Chinese red glaze differs from Example 4 in that the Baumé degree of the prepared glaze is between 30 and 35, while the rest is the same as in Example 4.
[0028] Comparative Example 4 A method for preparing Chinese red glaze differs from Example 4 in that step (3) is as follows: the glazed body is transferred into a firing furnace and fired in a single reduction firing process. When the temperature rises to 1000°C, a reducing gas (carbon monoxide to nitrogen volume ratio = 1:10, and oxygen content less than 0.6%) is introduced, and the temperature is directly raised to 1320°C and held for 30 minutes. Other steps are the same as in Example 4.
[0029] Comparative Example 5 A method for preparing a red glaze includes the following steps: (1) Glaze preparation: First, mix 38 parts feldspar, 10 parts calcite, 20 parts quartz, 12 parts kaolin, 2.5 parts copper oxide, 2 parts zinc oxide, 0.08 parts iron oxide, 2.5 parts tin oxide, and 3.5 parts zircon. Then, add the mixture to a ball mill and ball mill (the mass ratio of raw materials: balls: water is 1:2:0.8). The speed is 500 rpm. Ball mill until the fineness is ≤0.05% on a 10,000 mesh sieve. Adjust the glaze concentration to a Baume degree between 45 and 50 to obtain the glaze. (2) Glazing: Apply the glaze to the unglazed body in one go, with a thickness of 0.28-0.35mm, and let it air dry naturally; (3) Gradient firing: The glazed body is transferred into the firing furnace and fired in one reduction firing. When the temperature rises to 1000℃, reducing gas (carbon monoxide to nitrogen volume ratio = 1:10, and oxygen content is less than 0.6%) is introduced, and the temperature is directly raised to 1320℃ and held for 30 minutes. After cooling to 1100℃, the reducing gas is turned off and the body is allowed to cool naturally to room temperature.
[0030] Test case 1. Pottery was prepared according to the methods of Examples 4-6 and Comparative Examples 1-5, with 10 batches produced in each group. External observation, yield, and process reproducibility were then assessed, and the results are shown in Table 1. The yield was determined by randomly selecting 100 pieces from each batch and judging based on factors such as uniform glaze color, absence of blackening, glaze bubbles, oil flow, cracking, pure and bright red color, and gloss level greater than 85. The yield of each batch was calculated and the average value was taken.
[0031] Table 1 Statistical Results
[0032] As can be seen from Table 1, the porcelain glaze prepared by the formula and preparation process of this invention has a uniform and full color, a pure bright red color, high color saturation and yield, good process reproducibility, and stable process, and has important industrial application value.
[0033] While Comparative Example 1 used the preparation process of Example 4, it directly used copper oxide. In this case, some copper ions migrated prematurely at low temperatures, resulting in uneven copper distribution during the final color development. Comparative Example 2, however, did not add tin oxide or zircon, thus avoiding the formation of physical barriers in the subsequent high-temperature stages. + The glaze was also migrated, which affected its color development. In Comparative Example 3, the glaze had a low Baume degree, resulting in flow and dull color. In Comparative Example 4, the traditional firing method was used, and the high-temperature reduction started too early, causing excessive reduction of copper in some areas and resulting in dark red spots. In Comparative Example 5, copper oxide was used directly and the traditional firing method was used. Not only did the glaze surface have bubbles and flow, but the color was also uneven, turning black. The color intensity fluctuated greatly and the stability was poor.
[0034] 2. The performance of the Chinese red glazed porcelain obtained in Examples 4-6 was tested, and the results are shown in Table 2. Lead and cadmium migration were tested according to the relevant methods in GB 31604-2016; water absorption was tested according to the relevant methods in GB / T 3299-2011; and thermal shock resistance was tested according to the relevant methods in GB / T 3298-2022.
[0035] Table 2 Performance of Porcelain Products
[0036] As can be seen from Table 2, the porcelain glaze prepared by the method of the present invention has stable color display, safety, good thermal shock resistance and water absorption, and excellent overall performance, which can meet the performance requirements of daily ceramic products.
[0037] In summary, by optimizing the raw material composition and ratio, using copper source as a precursor for protection, and optimizing the firing process, this invention produces a Chinese red glaze with uniform color development, pure and stable red color, high yield, good repeatability, and excellent overall performance, thus possessing significant industrial application value.
[0038] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a Chinese red colored glaze, characterized in that, Includes the following steps: (1) Glaze preparation: The raw materials are mixed according to the following weight parts: feldspar 38-40 parts, calcite 10-12 parts, quartz 20-23 parts, kaolin 12-15 parts, copper source precursor 2.5-3.5 parts, zinc oxide 2-4 parts, iron oxide 0.08-0.12 parts, tin oxide 2.5-3.5 parts, zircon 3.5-4.5 parts, and ball milled to obtain glaze; wherein, the copper source precursor is pre-fired by nano copper oxide, kaolin and sucrose under an inert atmosphere, specifically: first, nano copper oxide, kaolin and sucrose are mixed in a mass ratio of 0.8-1.2:2:0.5 and then dry ball milled for 2-3 hours, then heated to 800±20℃ under an inert atmosphere and kept at that temperature for 1-3 hours, and after sintering, naturally cooled and ground for later use; (2) Glazing: Apply the glaze to the unglazed body in one go and let it air dry naturally; (3) Gradient firing: The glazed body is transferred into the firing furnace and fired at progressively higher temperatures, specifically: a. Low-temperature pre-calcination section: The temperature is increased from room temperature to 600℃ in an oxidizing atmosphere at a heating rate of 5-6℃ / min; b. Medium-temperature reduction start-up section: The temperature is raised from 600℃ to 980℃ at a heating rate of 3-4℃ / min, and a reducing atmosphere is introduced at 750℃; c. High-temperature color development section: Raise the temperature from 980℃ to 1270-1330℃ at a heating rate of 2-3℃ / min, introduce a strong reducing atmosphere, and hold for 30-40min. d. Cooling section: After cooling to 1100℃, the reducing gas is shut off, and the mixture is cooled to room temperature in a weak oxidizing atmosphere.
2. The method for preparing a Chinese red colored glaze according to claim 1, characterized in that, In step (1), the purity of the nano-copper oxide is ≥99%, D 50 ≤50nm; the D of the kaolin 90 ≤10μm; the heating rate to 800±20℃ is 4-5℃ / min.
3. The method for preparing a Chinese red colored glaze according to claim 1, characterized in that, In step (1), the particle size D of the copper source precursor 90 ≤10μm.
4. The method for preparing a Chinese red colored glaze according to claim 1, characterized in that, In step (1), the mass ratio of raw materials: balls: water is 1:1.5-2:0.7-0.8; the ball milling speed is 500-800 rpm; the ball milling is carried out until the fineness is less than 0.05% on a 10,000-mesh sieve, and the glaze concentration is adjusted to a Baume degree of 45-50.
5. The method for preparing a Chinese red colored glaze according to claim 1, characterized in that, In step (2), the thickness of the glaze applied in one application is 0.28-0.35 mm.
6. The method for preparing a Chinese red colored glaze according to claim 1, characterized in that, In step (3), the oxygen content in the oxidizing atmosphere of the low-temperature pre-burning section is 8-12%; the reducing atmosphere of the medium-temperature reduction start-up section is a mixture of carbon monoxide and nitrogen in a volume ratio of 1:10, and the oxygen content is less than 1.8%.
7. The method for preparing a Chinese red colored glaze according to claim 1, characterized in that, In step (3), the strong reducing atmosphere in the high-temperature color development section is a mixture of carbon monoxide and nitrogen in a volume ratio of 1:8, and the oxygen content is less than 0.6%; the oxygen content in the weak oxidizing atmosphere of the cooling section is 3-5%.
8. A Chinese red glaze prepared by the preparation method according to any one of claims 1-7.