Method for repairing green body

Abstract

The invention discloses a method for repairing a green body. The method comprises the following steps: weighing 20-35 parts by weight of kaolin, 10-30 parts by weight of albite, 0.5-2 parts by weight of talc, 15-25 parts by weight of clay, 20-35 parts by weight of quartz, 1-4 parts by weight of wollastonite and 10-15 parts by weight of kyanite powder, and carrying out ball milling and sieving to obtain prefabricated slurry; ball-milling and sieving 10-25 parts of refractory cotton, and adding a pigment into the prefabricated slurry to obtain the repairing slurry; and coating a to-be-repaired area with the repairing slurry, glazing, and sintering to 1100-1315 DEG C by adopting a segmented heating sintering method to obtain a repaired green body. By adopting the repairing method provided by the invention, the defects of cracking and high-temperature deformation of the green body can be reduced, the chromatic aberration is reduced, and the range of repairing the cracks of the green body can be expanded, so that the green body does not crack.

Description

Technical Field

[0001] The present invention relates to the technical field of blank repair, and particularly relates to a method for repairing a blank. Background Art

[0002] Cracking of the blank is one of the common defects in the production of ceramic products. The main reasons for blank cracking include uneven thickness of the blank, uneven shrinkage and drying inside the blank, too high moisture content of the blank when entering the kiln, raw material composition, and unreasonable firing system.

[0003] In the prior art, a patent with an application date of November 6, 2009 and a publication number of CN101717268B discloses a ceramic mud blank repair material, its preparation method and repair process. By slightly expanding the cracked part of the ceramic blank, the stress concentration at the cracked part of the blank is eliminated, and the cracked part is filled with the described ceramic mud blank repair material, changing the spatial connection mode between the blank particles. Using this method requires first expanding the cracked part of the blank and the width of the repaired crack is relatively narrow.

[0004] In the prior art, a patent with an application date of June 7, 2023 and a publication number of CN119100843A discloses a method for repairing porcelain defects. This method first uses refractory cotton to fill the blank bald or brown eyes of the porcelain, then fills with hot repair mud, then covers the filled part with a repair glaze mass, and after polishing, it is recycled for the second time, greatly improving the qualified rate of the repaired and re-fired blank bald or brown eyes of the porcelain.

[0005] The blanks repaired by the existing repair methods are prone to produce concave and convex defects during firing and cause color difference in the repaired area. The crack range of the repaired blank is within 2 millimeters and the firing temperature is below 1100°C.

[0006] Therefore, it is an urgent problem to be solved at present to expand the crack range of the repaired blank, increase the firing temperature, reduce the concave and convex defects and cracking in the repaired area of the blank, reduce the color difference and make the blank more flat and beautiful during firing. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the defects of low firing temperature of the repaired cracked blank, narrow repaired crack range and easy generation of concavity, convexity and cracking during firing in the prior art. Based on this, the present invention provides a method for repairing a blank.

[0008] To achieve the above object, the present invention provides the following technical solutions: S1. Clean the damaged area of the green body to be repaired and weigh 20 - 35 parts by weight of kaolin, 10 - 30 parts of albite, 0.5 - 2 parts of talc, 15 - 25 parts of clay, 20 - 35 parts of quartz, 1 - 4 parts of wollastonite, and 10 - 15 parts of kyanite powder as prefabricated powder materials. Ball mill according to the ratio of prefabricated powder materials: ball mill media: water = 1:1.5:0.6 and ball mill the median diameter of the prefabricated powder materials to 6 - 12 μm, then pass through a 60 - 100 mesh sieve to obtain a prefabricated slurry; S2. After ball milling and sieving 10 - 25 parts by weight of refractory cotton, add it to the prefabricated slurry, and add colorant and stir evenly. After sieving, a repair slurry is obtained. The process of ball milling and sieving is to add refractory cotton, water, and ball mill media according to the ratio of refractory cotton: ball mill media: water = 1:5:10, ball mill for 5 - 10 minutes, and then pass through a 60 - 100 mesh sieve; S3. Dry the repair slurry and coat it on the damaged area of the green body to be repaired. After glazing, use the segmented firing method to fire it to 1100 - 1315 °C to obtain a repaired green body. Further, the specific steps of firing to 1100 - 1315 °C by the segmented firing method are: at room temperature, heat it to 500 - 600 °C at a rate of 3 - 5 °C / min, then increase the temperature to 1100 - 1315 °C at a rate of 2 - 3 °C / min and hold for 1 h. After holding for 1 h, rapidly cool it at a rate of 5 - 6 °C / min to 500 - 600 °C, and finally cool it to 50 - 70 °C after 3 - 4 h.

[0009] An unreasonable firing regime will cause the phenomenon of cracking of the repaired green body. When heating from room temperature to 500 - 600 °C at a rate of 3 - 5 °C / min, the heating time is long, the free water and bound water are exhausted, and the shrinkage of the green body is slowed down. Quartz in the blank material has a regulating effect on the plasticity of the green body, can reduce shrinkage during drying, shorten the drying time and prevent the green body from deforming. However, during the firing process, it will undergo polymorphic transformation, causing volume changes in the green body. Slow heating can provide sufficient time to promote the polymorphic transformation of quartz and prevent the green body from deforming or cracking due to excessive volume expansion of quartz caused by rapid heating; then slowly increase the temperature to 1100 - 1315 °C at a rate of 2 - 3 °C / min, which is beneficial for the oxides in the green body to fully undergo oxidation reactions; holding for 1 h is beneficial for discharging the gas in the repaired green body. After holding for 1 h, rapidly cool it. Quenching is beneficial for enhancing the gloss of the glaze attached to the surface of the repaired green body and at the same time reducing the phenomenon of wind cracks in the repaired green body.

[0010] In addition, the selection of raw materials also affects the firing of the green body. Kaolin and clay provide plasticity, which is beneficial for drying without cracking after repair. Quartz can stabilize the firing temperature of the repaired green body, thereby reducing the width of the repaired cracks. Adding wollastonite and talc during the firing of the green body can promote the melting of quartz and reduce the firing temperature of the repaired area of the green body. The main chemical components of kyanite and the green body are both silica and alumina, and their compositions are similar. During the high-temperature firing process, the green body is prone to volume expansion during firing. Adding kyanite can reduce the defects of cracking and high-temperature deformation of the green body during firing, and reduce the probability of concavo-convex defects occurring after the green body is fired.

[0011] Adopting the above technical solution helps to overcome the problems of the small crack range of the repaired green body, low firing temperature and easy generation of concavo-convex defects in the prior art.

[0012] Furthermore, the average particle size of the refractory cotton is 0.4 - 1.25 mm.

[0013] Adding refractory cotton to the precast slurry, during firing, the refractory cotton fully fills the voids in the green body, which can improve the strength and toughness of the product. At the same time, it makes the high-temperature shrinkage rate of the repaired area close to that of the green body to be repaired, reducing the risk of cracking at the repair area due to the shrinkage rate difference between the two at high temperature. Moreover, the selection of the average particle size of the refractory cotton also has a certain impact on the repaired green body. When the average particle size of the refractory cotton is greater than 1.25 mm, white spots are likely to appear on the fired green body. When the average particle size of the refractory cotton is less than 0.4 mm, cracks are likely to appear in the repaired area. Selecting an average particle size of 0.4 - 1.25 mm and adding it to the precast repair slurry results in a better effect for the fired green body.

[0014] Furthermore, the method of drying the repair slurry and then coating it on the damaged area of the green body to be repaired is to dry the repair slurry to make the moisture content of the repair slurry 15% - 25%, and then after pugging and aging, brush the repair slurry on the damaged area of the green body to be repaired until it is flush with the surface of the damaged area of the green body to be repaired.

[0015] Furthermore, the colorant includes 1 - 3 parts by weight of vanadium zirconium yellow colorant, 0.2 - 2 parts of zirconium iron red colorant, and 0.02 - 2 parts of cobalt black colorant.

[0016] The addition of the colorant can reduce the color difference of the repaired green body and make the color of the repaired area close to that of the green body after firing.

[0017] Applying the green body repair method provided by the present invention to green body repair can repair green bodies with crack widths in the range of 0 - 15 mm.

[0018] The technical solution of the present invention has the following advantages: 1. The method for repairing a green body provided by the present invention uses a segmented firing method. First, when slowly heating to 500 - 600 °C, the heating time is long to exhaust free water and bound water and promote the quartz crystal form transformation, reduce the shrinkage of the green body, and prevent the green body from deforming or cracking. Then, when heating to 1100 - 1315 °C at a slower rate, it is beneficial for the oxides in the green body to fully undergo oxidation reactions. After holding for 1 h, it is rapidly cooled. The rapid cooling is beneficial to enhancing the gloss of the glaze attached to the surface of the repaired green body, and at the same time reducing the phenomenon of thermal cracking of the repaired green body.

[0019] 2. In the method for repairing a green body provided by the present invention, adding refractory cotton to the prefabricated slurry can improve the strength and toughness of the product, and at the same time make the high-temperature shrinkage rate of the repaired area similar to that of the green body to be repaired, reducing the risk of cracking at the repair area due to the shrinkage rate difference between the two at high temperature.

[0020] 3. The method for repairing a green body provided by the present invention has a simple process. Using raw materials such as kyanite powder, zirconium - alumina yellow pigment, zirconium - iron red pigment, cobalt black pigment, etc. to prepare the repair slurry can reduce the defects of green body cracking and high - temperature deformation, and at the same time make the color of the repaired area similar to that of the green body to be repaired, reducing the color difference and making the product more beautiful.

[0021] 4. Applying the repair method provided by the present invention to the repair of green bodies can expand the range of cracks in the repaired green body, and the green body within the crack width range of 0 - 15 mm can be repaired without cracking. Description of the Drawings

[0022] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is the firing temperature curve of the segmented heating and firing method in the present invention.

[0024] Figure 2 It is the appearance photo of the green body to be repaired.

[0025] Figure 3 It is the appearance photo after applying the repair slurry provided by the present invention to the area to be repaired.

[0026] Figure 4 It is the effect picture after repairing by the method of Example 1 of the present invention. Detailed Embodiments

[0027] The following embodiments are provided to better further understand the present invention. It is not limited to the best mode, and does not limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with those of other prior arts falls within the protection scope of the present invention.

[0028] For those embodiments in which specific experimental steps or conditions are not specified, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments whose manufacturers are not specified, they are all conventional reagent products that can be obtained through commercial purchase.

[0029] Example 1 S1. Determine the damaged area on the surface of the green body to be repaired, clean the damaged area, and remove surface dust and impurities. Weigh 20 parts of kaolin, 14 parts of albite, 0.5 part of talc, 17 parts of clay, 35 parts of quartz, 2 parts of wollastonite, and 10 parts of kyanite powder as prefabricated powder materials. Put the prefabricated powder materials prepared according to the above ratio into a ball mill, and add ball mill balls and water according to the ratio of prefabricated powder materials: ball mill balls: water = 1:1.5:0.6. Ball mill the powder materials until the median diameter particle size is controlled within 6 - 8 μm, then pass through a 60 - mesh sieve, and finally stir evenly with a stirrer; S2. Weigh 10 parts of refractory cotton with a particle size of 0.4 - 1.25 mm and add it to the ball mill. At the same time, add water and ball mill balls according to the ratio of refractory cotton: ball mill balls: water = 1:5:10 and ball mill for 10 minutes, then pass through a 100 - mesh sieve; Add the ball - milled and sieved refractory cotton to the prefabricated slurry in step S1 and stir evenly. Weigh 1 part of vanadium - zirconium yellow pigment, 0.2 part of zircon - iron red pigment, and 1 part of cobalt black pigment, add them to the prefabricated slurry, stir evenly, and pass through a sieve to obtain a repair slurry; S3. Dry the repair slurry until the moisture content is 16%, then add it to a clay pug mill to pug the clay. After aging for 2 days, coat it on the damaged area of the green body to be repaired. Finally, after glazing, fire the repaired green body at a rate of 3.5 °C / min to 573 °C at room temperature, then increase the temperature at a rate of 3 °C / min to 1315 °C, hold for 1 h, after holding for 1 h, quickly cool at a rate of 5.5 °C / min to 600 °C, and finally cool to 50 °C after 4 h by the firing method.

[0030] Example 2 S1. Determine the damaged area on the surface of the green body to be repaired, clean the damaged area to remove surface dust and impurities. Weigh 26 parts of kaolin, 10 parts of albite, 0.8 part of talc, 15 parts of clay, 26 parts of quartz, 1 part of wollastonite, and 11 parts of kyanite powder as prefabricated powder materials. Put the prefabricated powder materials prepared according to the above ratio into a ball mill, and add ball mill media and water according to the ratio of prefabricated powder materials: ball mill media: water = 1:1.5:0.6. Ball mill the powder materials until the median diameter particle size is controlled within 7 - 12 μm, then pass through a 100 - mesh sieve, and finally stir evenly with a stirrer; S2. Weigh 13 parts of refractory cotton with a particle size of 0.4 - 1.25 mm and add it to the ball mill. At the same time, add water and ball mill media according to the ratio of refractory cotton: ball mill media: water = 1:5:10, and ball mill for 10 minutes and then pass through an 80 - mesh sieve; Add the ball - milled and sieved refractory cotton to the prefabricated slurry in step S1 and stir evenly. Weigh 1.5 parts of vanadium - zirconium yellow pigment, 0.8 part of zircon - iron red pigment, and 0.02 part of cobalt black pigment, add them to the prefabricated slurry, stir evenly, and pass through a sieve to obtain the repair slurry; S3. Dry the repair slurry until the moisture content is 18%, then add it to a clay kneader to knead the clay. After aging for 3 days, coat it on the damaged area of the green body to be repaired. Finally, after glazing, fire the repaired green body at a rate of 5 °C / min from room temperature to 600 °C, then increase the temperature at a rate of 3 °C / min to 1280 °C, hold for 1 h, after holding for 1 h, quickly cool at a rate of 5.5 °C / min to 550 °C, and finally cool to 60 °C after 3 h using this firing method.

[0031] Example 3 S1. Determine the damaged area on the surface of the green body to be repaired, clean the damaged area to remove surface dust and impurities. Weigh 28 parts of kaolin, 30 parts of albite, 2 parts of talc, 19 parts of clay, 20 parts of quartz, 4 parts of wollastonite, and 15 parts of kyanite powder as prefabricated powder materials. Put the prefabricated powder materials prepared according to the above ratio into a ball mill, and add ball mill media and water according to the ratio of prefabricated powder materials: ball mill media: water = 1:1.5:0.6. Ball mill the powder materials until the median diameter particle size is controlled within 9 - 12 μm, then pass through an 80 - mesh sieve, and finally stir evenly with a stirrer; S2. Weigh 25 parts of refractory cotton with a particle size of 0.4 - 1.25 mm and add it to the ball mill. At the same time, add water and ball mill media according to the ratio of refractory cotton: ball mill media: water = 1:5:10, and ball mill for 10 minutes and then pass through a 100 - mesh sieve; Add the ball - milled and sieved refractory cotton to the prefabricated slurry in step S1 and stir evenly. Weigh 3 parts of vanadium - zirconium yellow pigment, 1.6 parts of zircon - iron red pigment, and 2 parts of cobalt black pigment, add them to the prefabricated slurry, stir evenly, and pass through a sieve to obtain the repair slurry; S3. Dry the repair slurry until the moisture content is 22%, then add it to a clay kneader to knead the clay. After aging for 2 days, coat it on the damaged area of the green body to be repaired. Finally, after glazing, fire the repaired green body using a firing method where it is heated from room temperature to 524°C at a rate of 4.5°C / min, then heated to 1100°C at a rate of 2°C / min and held for 1 h. After holding for 1 h, rapidly cool it to 506°C at a rate of 6°C / min, and finally cool it to 53°C over 3.5 h.

[0032] Example 4 S1. Determine the damaged area on the surface of the green body to be repaired, clean this damaged area, and remove surface dust and impurities. Weigh 31 parts of kaolin, 22 parts of albite, 0.9 part of talc, 25 parts of clay, 24 parts of quartz, 2.6 parts of wollastonite, and 13 parts of kyanite powder as prefabricated powder materials. Put the prefabricated powder materials prepared according to the above ratio into a ball mill, and add ball mill media and water according to the ratio of prefabricated powder materials: ball mill media: water = 1:1.5:0.6. Ball mill the powder until the median diameter particle size is controlled within 6 - 10 μm, then pass it through a 60-mesh sieve, and finally stir it evenly with a stirrer. S2. Weigh 16 parts of refractory cotton with a particle size of 0.4 - 1.25 mm and add it to the ball mill. At the same time, add water and ball mill media according to the ratio of refractory cotton: ball mill media: water = 1:5:10 and ball mill for 10 minutes, then pass it through a 100-mesh sieve. Add the ball milled and sieved refractory cotton to the prefabricated slurry in step S1 and stir evenly. Weigh 3 parts of vanadium zirconium yellow pigment, 0.8 part of zirconium iron red pigment, and 1.2 parts of cobalt black pigment, add them to the prefabricated slurry, stir evenly, and pass it through a sieve to obtain the repair slurry. S3. Dry the repair slurry until the moisture content is 20%, then add it to a clay kneader to knead the clay. After aging for 2 days, coat it on the damaged area of the green body to be repaired. Finally, after glazing, fire the repaired green body using a firing method where it is heated from room temperature to 585°C at a rate of 5°C / min, then heated to 1300°C at a rate of 2.5°C / min and held for 1 h. After holding for 1 h, rapidly cool it to 524°C at a rate of 5.5°C / min, and finally cool it to 50°C over 4 h.

[0033] Comparative Example 1 Comparative Example 1 is a comparative test example of Example 1. The difference from Example 1 is that in Comparative Example 1, after glazing, the repaired green body is fired using a firing method where it is directly heated from room temperature to 1315°C at a rate of 3.5°C / min and held for 1 h. After holding for 1 h, it is rapidly cooled to 600°C at a rate of 5.5°C / min, and finally cooled to 50°C over 4 h.

[0034] Comparative Example 2 Comparative Example 2 is a comparative test example of Example 1. The difference from Example 1 is that after glazing in Comparative Example 1, it is fired to 573°C at a rate of 3.5°C / min at room temperature, then heated to 1315°C at a rate of 3°C / min and held for 1 h, and after holding for 1 h, it is naturally cooled to 50°C at room temperature for firing the repaired green body.

[0035] Comparative Example 3 Comparative Example 3 is a comparative test example of Example 1. The difference from Example 1 is that kyanite powder is not added when preparing the prefabricated slurry.

[0036] Comparative Example 4 Comparative Example 3 is a comparative test example of Example 1. The difference from Example 1 is that the particle size of the refractory cotton is 0.25 mm.

[0037] Comparative Example 5 Comparative Example 3 is a comparative test example of Example 1. The difference from Example 1 is that the particle size of the refractory cotton is 2 mm.

[0038] Comparative Example 6 Comparative Example 6 is a comparative test example of Example 1. The difference from Example 1 is that refractory cotton is not added when preparing the repair slurry.

[0039] Examples 1-4 and Comparative Examples 1-5 were tested, and the test judgments were as follows: 1. Judgment of the repaired crack width: After repairing, glazing, and firing ceramic semi-finished products with different crack widths using the repair slurry, observe whether the repaired area cracks. 2. Judgment of the color difference of the repaired part: During glazing of Examples 1-4 and Comparative Examples 1-6, mark the repaired area, and then measure the whiteness of the repaired area and the non-repaired area after glazing and firing respectively with a whiteness meter, and calculate the deviation δ, where δ = (whiteness of the repaired area - whiteness of the non-repaired area) / whiteness of the non-repaired area. 3. Drying qualification rate: Take 100 samples with a crack width of 15 mm, repair them with the repair slurry, and after repair, place them in a ventilated place to dry naturally. Observe the samples. If cracks, pits, or collapses appear in the repaired area, it is judged as unqualified, otherwise it is judged as qualified. 4. Judgment of the repair qualification rate: Take 100 samples with a crack width of 15 mm, repair them with the repair slurry, and after repair, place them in a ventilated place to dry naturally. Observe the samples. If cracks, pits, or collapses appear in the repaired part, it is judged as unqualified, otherwise it is judged as qualified. Glaze and fire the qualified dried samples. After firing, if cracks, pits, or collapses appear in the repaired area, and the glaze surface of the repaired area is significantly yellowed (with a visible color difference from other parts), it is judged as unqualified, otherwise it is judged as qualified. The repair qualification rate = number of qualified samples after firing / total number of samples.

[0040] The test results are shown in Table 1 below: Table 1

[0041] As can be seen from the test results in Table 1, when the method for repairing ceramic green bodies provided by the present invention is used to repair the ceramic green bodies in Examples 1-4, the repair is easy to operate, the green bodies do not crack, and there are no concave and convex defects on the surface of the repaired area after firing, and the glaze surface has luster. By setting Comparative Examples 1-2, it can be demonstrated that the segmented firing method is beneficial to reducing the generation of concave and convex defects and cracks on the surface of the repaired area of the green body. Comparative Example 3 can demonstrate that the addition of kyanite powder reduces the probability of concave and convex defects occurring after the green body is fired. Comparative Examples 4-6 can demonstrate that the addition of refractory cotton and the control of the particle size range of refractory cotton also have a certain impact on the repaired area: adding refractory cotton to the prefabricated slurry can improve the strength and toughness of the product, and at the same time make the high-temperature shrinkage rate of the repaired area similar to that of the green body to be repaired, reducing the risk of cracking at the repaired area due to the shrinkage rate difference between the two at high temperature. When the average particle size of the refractory cotton is greater than 1.25 mm, white spots are likely to appear on the fired green body. When the average particle size of the refractory cotton is less than 0.4 mm, cracks are likely to appear in the repaired area. Selecting an average particle size of 0.4-1.25 mm and adding it to the prefabricated repair slurry gives better results for the fired green body.

[0042] In summary, for the method for repairing green bodies provided by the present invention, when using the segmented firing method, first slowly raise the temperature to 500-600 °C, with a long heating time, to drain free water and bound water and promote the transformation of quartz crystal form, reducing the shrinkage of the green body to prevent the green body from deforming or cracking; then raise the temperature to 1100-1315 °C at a slower rate, which is beneficial for the oxides in the green body to fully undergo oxidation reactions; after holding for 1 h, rapidly cool down. The rapid cooling is beneficial for enhancing the luster of the glaze attached to the surface of the repaired green body, and at the same time reducing the phenomenon of wind cracks in the repaired green body.

[0043] Using raw materials such as kyanite powder, refractory cotton, vanadium-zirconium yellow pigment, zirconium-iron red pigment, and cobalt black pigment to prepare the repair slurry can reduce the defects of green body cracking and high-temperature deformation, and at the same time make the color of the repaired area similar to that of the green body to be repaired, reducing the color difference and making the product more beautiful.

[0044] Applying the repair method provided by the present invention to the repair of green bodies can expand the range of cracks in the repaired green bodies, and the green bodies within the crack width range of 0-15 mm do not crack after repair.

[0045] Obviously, the above-mentioned embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for repairing a green body, characterized in that, Including: S1. Clean the damaged area of the green body to be repaired and weigh 20 - 35 parts by weight of kaolin, 10 - 30 parts of albite, 0.5 - 2 parts of talc, 15 - 25 parts of clay, 20 - 35 parts of quartz, 1 - 4 parts of wollastonite, and 10 - 15 parts of kyanite powder as prefabricated powder materials. Ball mill according to the ratio of prefabricated powder materials: ball mill media: water = 1:1.5:0.6, and ball mill the median diameter of the prefabricated powder materials to 6 - 12 μm, then pass through a 60 - 100 mesh sieve to obtain prefabricated slurry; S2. Weigh 10 - 25 parts by weight of refractory cotton, ball mill and sieve it, then add it to the above - mentioned prefabricated slurry, and add colorant, stir evenly and sieve to obtain repair slurry. The process of ball milling and sieving is to add refractory cotton, water and ball mill media according to the ratio of refractory cotton: ball mill media: water = 1:5:10, ball mill for 5 - 10 minutes, and pass through a 60 - 100 mesh sieve; S3. Dry the repair slurry and coat it on the damaged area of the green body to be repaired. After glazing, use the segmented firing method to fire it to 1100 - 1315 °C to obtain the repaired green body. The specific steps of firing to 1100 - 1315 °C by the segmented firing method are: at room temperature, heat it to 500 - 600 °C at a rate of 3 - 5 °C / min, then increase the temperature to 1100 - 1315 °C at a rate of 4 - 6 °C / min and hold for 1 h. After holding for 1 h, rapidly cool it to 500 - 600 °C at a rate of 5 - 6 °C / min, and finally cool it to 50 - 70 °C after 3 - 4 h.

2. The repair method of a green body according to claim 1, characterized in that: The method for repairing a green body according to claim 2, wherein 10 - 25 parts by weight of refractory cotton is used. The average particle size of the refractory cotton is 0.4 - 1.25 mm.

3. A method for repairing a green body according to claim 1, characterized in that: The method of drying the repair slurry and coating it on the damaged area of the green body to be repaired is to dry the repair slurry to make the moisture content of the repair slurry 15% - 25%, then after pugging and aging, brush the repair slurry to be flush with the surface of the damaged area of the green body to be repaired.

4. A method for repairing a green body according to claim 1, characterized in that: The colorant includes 1 - 3 parts by weight of vanadium - zirconium yellow colorant, 0.2 - 2 parts of zirconium - iron red colorant, and 0.02 - 2 parts of cobalt black colorant.

5. A method for repairing a green body according to any one of claims 1-4, characterized in that: Apply the repair method to repair the cracks in the green body, and the crack width of the repaired green body is in the range of 0 - 15 mm.

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