Glaze-sand making process for super-high voltage porcelain insulator

Abstract

The application relates to the technical field of porcelain insulators, and particularly discloses a glaze-coated sand preparation process for super-high-voltage porcelain insulators, which comprises the following steps: I. uniformly mixing glaze powder and porcelain sand; II. continuously stirring while adding glue to the uniformly stirred porcelain sand and glaze powder, so that the glue wraps the glaze powder on the porcelain sand to form the glaze-coated sand with the porcelain sand as the inner layer, the glaze powder as the middle layer and the glue as the outer layer; the mass ratio of the porcelain sand to the glaze powder in step I is controlled to be 1:(0.6-0.9); the glue mass is 1 / 4 to 1 / 3 times the glaze powder mass in step II; after the preparation of the glaze-coated sand, the container is tightly sealed to prevent the glaze-coated sand from drying to ensure that the surface of the glaze-coated sand is sticky when used. The scheme is used to solve the problems of glaze falling and glaze-coated sand falling in the use process of the existing glaze-coated sand, which affects the final bending strength.

Description

Technical Field

[0001] This invention relates to the field of porcelain insulator technology, specifically to a process for manufacturing glazed sand for ultra-high voltage porcelain insulators. Background Technology

[0002] With the development of the national economy and the improvement of electrification levels, electricity has become increasingly prominent in the energy sector, and ensuring electricity security has gradually become one of the core elements of the new energy security strategy. Due to the surge in electricity consumption, the proportion of electricity on the consumer side will gradually increase. Faced with ever-growing electricity demand, the task of ensuring a stable supply of electricity to the industry remains arduous.

[0003] To meet the needs of high-voltage power transmission projects, porcelain insulators are also divided into high-voltage insulators and ultra-high-voltage insulators according to their application scope. Currently, the highest-grade ultra-high-voltage insulator is the high-strength aluminum porcelain insulator. Due to the wide range of ultra-high voltage applications, the bending strength requirement for high-strength aluminum porcelain insulators before glazing is no less than 140MPa, and after glazing, the bending strength requirement is no less than 160MPa. However, with the development of the electrical age, the porcelain industry is also constantly developing. For high-voltage power transmission projects with even higher pressures, such as 500 kV to 1000 kV, the bending strength requirements for insulators are even higher.

[0004] Currently, there is increasing research on insulators in the industry, and our company has also conducted in-depth research on porcelain insulators. For glazed materials, we can achieve a bending strength of over 200MPa after glazing. However, because porcelain insulators need to be fixedly installed, they must be used in conjunction with metal parts. For example, suspension porcelain insulators need to be used with iron caps and steel feet. To improve the bonding strength between the iron caps, steel feet and porcelain insulators, sand is often applied to the surface of the insulator where the iron caps and steel feet are installed to increase the friction coefficient of the porcelain insulators, thereby improving the connection strength between the iron caps, steel feet and porcelain insulators. However, because sand has low strength and a large difference in thermal expansion coefficient compared to porcelain insulators, the overall bending strength of porcelain insulators that originally achieved a bending strength of over 200MPa after glazing actually decreases under thermal stress, resulting in a decline in the electromechanical performance of porcelain insulators.

[0005] In existing technologies, to improve the strength of porcelain insulators after sand coating, it has been proposed to treat the porcelain sand before coating, such as by coating the surface of the porcelain sand with glaze. This allows the glazed porcelain sand to be surrounded by the glaze after sintering, providing compressive stress to the inside of the insulator and thus improving the mechanical strength and bonding strength of the porcelain insulator. However, while this glazed sand coating helps improve the mechanical strength of the porcelain insulator, in actual production, there are still problems such as glaze falling off the surface of the porcelain sand and sand shedding from the glazed blank. This results in the fired porcelain insulator having problems such as insufficient sand, easy sand shedding, and only a small improvement in bending strength. Summary of the Invention

[0006] The present invention aims to provide a manufacturing process for glazed sand used in ultra-high voltage porcelain insulators, in order to solve the problem of glaze falling off during the use of existing glazed sand, which affects the final bending strength.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A process for manufacturing glazed sand for ultra-high voltage porcelain insulators includes the following steps: I. Mix the glaze powder and porcelain sand evenly; II. While the porcelain sand and glaze powder are being stirred evenly, glue is added continuously so that the glue coats the glaze powder onto the porcelain sand, forming a glaze-coated sand with an inner layer of porcelain sand, a middle layer of glaze powder, and an outer layer of glue.

[0008] Preferably, as an improvement, the mass ratio of ceramic sand to glaze powder in step I is controlled at 1:(0.6-0.9).

[0009] Preferably, as an improvement, the mass of the adhesive in step II is 1 / 4 to 1 / 3 times the mass of the glaze powder.

[0010] Preferably, as an improvement, the glazed sand is placed in a sealed container after preparation to prevent it from drying out, thus ensuring that the surface of the glazed sand remains sticky when used.

[0011] Preferably, as an improvement, the fineness of the glaze powder is less than 80 micrometers.

[0012] Preferably, as an improvement, the glaze powder is prepared by grinding the following raw materials in the indicated mass fractions after uniform mixing: 10-20 parts microcline, 10-20 parts sodium feldspar, 5-15 parts high plasticity clay, 7-12 parts kaolin, 10-14 parts calcined talc, 4-10 parts wollastonite, 15-25 parts quartz powder, 6-10 parts zirconium silicate, and 2-6 parts alumina.

[0013] Preferably, as an improvement, the plagioclase is 10-18 parts and the albite is 12-20 parts. This scheme enables the glaze formula to reduce the melting temperature of the glaze, reduce the high-temperature viscosity of the glaze and increase the gloss of the glaze, while also minimizing the impact on the chemical stability of the glaze. It ensures that the expansion coefficient of the glaze can match both the blank and the porcelain sand used to coat the glaze, thus ensuring that the bending strength of the glaze blank is significantly improved relative to the blank, and that the bending strength of the glaze blank can still be significantly improved after sanding.

[0014] Preferably, as an improvement, the calcined talc is 10-12 parts; by controlling the amount of calcined talc, the calcined talc can improve the mechanical strength and thermal stability of the glaze, and is conducive to combining with other raw materials to control the annual growth of the glaze within a reasonable range, thus ensuring the excellent quality of the glaze surface after the porcelain is fired.

[0015] Preferably, as an improvement, the quartz powder is 17-22 parts. By controlling the quartz powder, the silica content in the glaze glass is increased, which acts as a skeleton and helps to reduce the expansion coefficient of the glaze and improve the wear resistance, hardness, strength, whiteness, transparency and chemical stability of the glaze surface.

[0016] Preferably, as an improvement, the chemical composition of the glaze powder includes: 60-72% SiO2, 14-17% Al2O3, less than 0.7% Fe2O3, 3-4% CaO, 3-5% MgO, 2-3.5% K2O, 1.5-3% Na2O, and 4-7% ZrO2.

[0017] The principle and advantages of this solution are as follows: This invention uses glaze powder, porcelain sand, and glue to create glazed sand. Because the glaze powder is first stirred with the porcelain sand, the inner layer of the porcelain sand is first coated with a layer of glaze powder. Then, with the addition of glue, the glaze powder is coated with glue. Glaze powder that did not adhere during the stirring process will also be mixed into the glue, forming glazed glue, which increases the content of glaze powder coating the porcelain sand (making the glazed sand have a structure with porcelain sand in the center, glaze powder in the middle layer, and glazed glue on the outer layer). It also increases the glaze content on the glaze blank, which is beneficial to the coating strength of the glaze on the porcelain sand after subsequent firing, and makes the expansion coefficient of the porcelain insulator surface gradually transition, which helps to improve the bending strength of the porcelain insulator.

[0018] According to the inventor's research, the main reason why the current method of coating with glazed sand results in problems such as insufficient sand, easy sand shedding, and minimal improvement in flexural strength of porcelain insulators is that the adhesive is located in the inner layer while the glaze is located on the surface. During the molding, preparation, or use of the glazed sand, the glaze on the surface of adjacent glazed sand layers rubs against each other, causing the glaze to be scraped off. During the storage process, as the middle layer of adhesive dries, the adhesion of the glaze also decreases, further reducing the amount of glaze on the glazed sand. During the sand coating process, the surface of the glazed sand is glaze and has no adhesiveness, but the adhesive on the glazed blank will reduce its adhesiveness due to the high water absorption of the blank. This results in the glazed sand not adhering firmly after sand coating, leading to sand shedding or separation before firing. During the firing process, as the adhesive vaporizes / decomposes at high temperatures, if the glaze on the surface of the porcelain sand is already insufficient, the glaze cannot form a coating on the porcelain sand, causing the surface porcelain sand to easily shed after firing, and also resulting in a small improvement in flexural strength.

[0019] This method involves first mixing the glaze powder with the porcelain sand, allowing the glaze powder to adhere to the surface of the porcelain sand due to its powdery structure. Then, under the action of glue, the glaze powder already adhering to the porcelain sand is completely coated. During the mixing process, glaze powder that is not in direct contact with the porcelain sand surface will also be mixed with the glue and coated onto the porcelain sand surface. After the glaze-coating sand adheres to the surface of the glazed blank that has already undergone one glazing, because the surface glue of the glaze-coating sand contains glaze powder and the middle layer contains glaze powder, the glaze-coating sand is further adhered to the surface of the glazed blank by sandblasting or filling and extrusion. Under the spraying or extrusion force, the glaze-coating sand will be embedded into the glaze material of the glazed blank, so that during sintering, the surface of the blank is covered with glaze material from the inside out, and the glaze material interacts with each other, with the glaze material and the sand... During sintering, the glaze and the blank undergo mutual erosion, diffusion, and reaction through physicochemical reactions. This prevents the glaze-coated sand from falling off after the blank is coated with sand, and also eliminates the problem of sand falling off or separating during sintering. As a result, the porcelain sand in the fired porcelain insulator is encased by a thicker layer of glaze, ensuring the strength of the glaze's coating on the porcelain sand after firing. This also allows for a gradual transition in the coefficient of thermal expansion of the porcelain insulator's surface, which significantly improves the bending strength of the porcelain insulator. The glazed and sand-coated porcelain insulators of this invention can achieve a bending strength as high as 220-230 MPa (compared to only 170 MPa for high-grade blanks before glazing), meeting the performance requirements of porcelain insulators for ultra-high voltage and even extra-high voltage power transmission projects.

[0020] Furthermore, by controlling the amounts of microcline, albite, Ordos clay, kaolin, calcined talc, wollastonite, quartz powder, zirconium silicate, and alumina, this invention ensures that the content of alumina, calcium oxide, magnesium oxide, sodium oxide, and zirconium oxide in the resulting glaze is kept within a very suitable range. Under the synergistic effect of the raw materials, the excellent effects of each raw material are maximized (combining the viscosity, high-temperature fluidity, suspension, gloss, and strength of the glaze), resulting in the most ideal overall effect. This greatly improves the bending strength of the suspended porcelain after sanding and also takes into account the expansion coefficient with the porcelain sand, thereby ensuring a gradual transition of the expansion coefficient on the surface of the porcelain insulator. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the manufacturing process of glazed sand for ultra-high voltage porcelain insulators according to an embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional view of the glazed sand structure produced by the glazed sand manufacturing process for ultra-high voltage porcelain insulators according to an embodiment of the present invention.

[0023] Figure 3 It is an inverted suspension porcelain insulator.

[0024] Figure 4 This is a schematic diagram of the head structure after glazing sand is applied to the glaze blank in an embodiment of the present invention. Detailed Implementation

[0025] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings of the instruction manual include: porcelain sand 1, glaze powder 2, and glue 3.

[0026] Example 1 Combination Figures 1 to 4 A process for manufacturing glazed sand for ultra-high voltage porcelain insulators includes the following steps: I. Weigh the porcelain sand and glaze powder according to the mass ratio of porcelain sand to glaze powder 1:(0.6~0.9). The fineness of the glaze powder is less than 80 micrometers, and the porcelain sand is C130 porcelain with a particle size of 0.8~1.5mm. Mix the glaze powder and porcelain sand evenly using a mixer. II. While the porcelain sand and glaze powder are thoroughly mixed, continue stirring and gradually add glue (the glue used should be aged and free of lumps). This allows the glue to coat the glaze powder onto the porcelain sand, forming a glaze-coated sand layer with an inner layer of porcelain sand, a middle layer of glaze powder, and an outer layer of glue (e.g., glaze-coated sand). Figure 2 (As shown). This step yields glazed sand with distinct, slightly sticky particles coated with glaze. The particle size of the glazed sand is 1.4–1.8 mm. During the preparation of the glazed sand, the mass of the adhesive is 1 / 4 to 1 / 3 of the mass of the glaze powder.

[0027] After the glazing sand is formed, a quality inspection is carried out on the glazing sand to confirm whether the quality of the glazing sand meets the standard requirements (the particle size must meet the standard, and the porcelain sand, glaze, and adhesive must be well bonded and the glaze must not fall off). If the standard requirements are met, the qualified glazing sand is put into a special container for later use to prevent moisture loss and the surface adhesive of the glazing sand from drying out, and to ensure that the glazing sand for later use is in a sticky state.

[0028] If the quality of the glazing sand is substandard, if there is too much glue, add glaze powder and porcelain sand to make a uniform glaze sand mixture; if there is too little glue, continue to add glue until the glazing sand meets the standard requirements.

[0029] The glaze powder used in the above process is prepared by grinding the following raw materials in the indicated mass fractions: 10-20 parts microcline, 10-20 parts sodium feldspar, 5-15 parts high plasticity clay (Ordos clay is used in this embodiment), 7-12 parts kaolin, 10-14 parts calcined talc, 4-10 parts wollastonite, 15-25 parts quartz powder, 6-10 parts zirconium silicate, and 2-6 parts alumina.

[0030] The chemical composition of the obtained glaze powder is as follows:

[0031] The aforementioned glaze can be used both for the production of glazing sand and for the first glazing of blanks. Taking a suspension porcelain insulator as an example, the process of glazing and sanding a porcelain insulator using the aforementioned glaze powder and glazing sand is as follows: Step 1: First glazing of the porcelain insulator umbrella: Prepare the glaze slurry from the raw materials / glaze powder used to make the glaze powder (sieve through a 360-mesh screen, the residual weight after sieving is 0.05%~0.18%, and the specific gravity of the glaze slurry is 1.45~1.55g / cm³). 3 Then, the head and umbrella-shaped parts of the unglazed blank are completely immersed in the glaze slurry. The glaze is applied to the entire inside and outside of the ceramic insulator by immersion glazing, resulting in a glazed blank. In this step, because the sintered blank has a very high water absorption rate, the glaze adheres to the surface of the blank after immersion in the glaze slurry due to water absorption. The glaze immersion requirements are: the glaze thickness is controlled at 0.25-0.60 mm, and the immersion time is 5-7 seconds.

[0032] Step 2: Applying glaze sand to the glazed blank: Apply glaze-containing adhesive to the head of the glazed blank. The glaze-containing adhesive is an adhesive mixed with glaze slurry. The mass ratio of glaze slurry to adhesive in the glaze-containing adhesive is controlled at 1:(0.8~1.1). The glaze slurry used is the same as the glaze slurry used in the first glazing of the head umbrella. The adhesive used in this step and the adhesive used in the glaze sand are both commonly used sand-applying adhesives in the industry, such as CMC adhesive. Then, apply the glaze sand containing glaze powder to the glazed blank with glaze-containing adhesive to obtain a glazed and sanded blank.

[0033] In this step, the outermost layer of the glazed sand is an adhesive layer, which is sticky. The glaze-containing adhesive also has high viscosity, allowing the glazed sand to adhere evenly to the surface of the glazed blank head (without sand falling off, piling up, or lacking sand, and with good uniformity), resulting in a glazed and sand-coated blank. This glazed and sand-coated blank allows for a thicker glaze on the blank, which is beneficial for improving the mechanical strength of the sintered porcelain insulator. Furthermore, after the glazed sand is pressed into the glaze-containing adhesive, the glaze is evenly distributed in each layer, thus ensuring that during the sintering process, the glaze, the porcelain sand, and the blank in each layer erode, diffuse, and react with each other, forming a complete whole. The porcelain sand in the glazed sand is precisely wrapped by the glaze, which further improves the sand-coating strength of the porcelain sand.

[0034] To increase the speed of sand application, the glaze blank is inverted (e.g., Figure 3 As described above, the head of the glazed blank is facing down, and the inner hole of the head of the glazed blank is facing up. When applying sand, the glazing sand on the outer surface of the head is adhered by sandblasting, and the sand on the inner surface of the head is adhered by filling sand. The sand filling method is to fill the inner hole of the head with sticky glazing sand. By utilizing the weight of the glazing sand and the mutual squeezing force after filling, the inner surface of the glazed blank is evenly covered with glazing sand. After the adhesion is completed, the blank is inverted 180° to pour out the excess glazing sand in the inner hole of the glazed blank.

[0035] After the porcelain insulator is glazed and sanded, the glazed and sanded blank is placed in a drawer kiln for glazing and firing, and then cooled to room temperature to produce high-grade suspended porcelain, which can be used in ultra-high voltage and even extra-high voltage power transmission projects.

[0036] In this embodiment, the raw materials for the glaze powder were: 15 parts microcline, 15 parts albite, 10 parts Ordos clay, 9 parts kaolin, 12 parts calcined talc, 7 parts wollastonite, 20 parts quartz powder, 8 parts zirconium silicate, and 4 parts alumina. The glaze powder prepared using the above process was then tested. During the testing process, the ratio of glaze powder to adhesive in the glazing sand and the ratio of glaze slurry to adhesive in the glaze-containing adhesive were varied. Multiple test results were obtained, as follows: Test Group A - Test Group H: Table 1 - Experimental data and results of experimental groups A to H

[0037] The test data above show that the proportion of glaze powder in the glazed sand of the AD test group is significantly higher, and the proportion of glaze slurry in the glaze-containing adhesive is appropriate, so that the bending strength of the porcelain insulator can approach or even exceed 230MPa.

[0038] Example 2 This second example is used to verify the glaze powder raw materials of the first example, and the specific composition of each raw material is as follows: Microcline was selected from Shaanxi Province, and its main chemical analysis parameters are as follows:

[0039] The sodium feldspar used is from Linxiang, and its main chemical analysis indicators are as follows:

[0040] Ordos clay is a type of clay with a high hydration rate, averaging 95%. It is also a highly plastic clay with an average binding strength of around 5.0 MPa. Its main chemical control indicators are as follows:

[0041] The kaolin used is from Xianyang, which is a medium-to-low plastic clay with an average binding strength of about 0.5 MPa. Its main chemical control indicators are as follows:

[0042] Calcined talc from Zichuan was used, and its main chemical analysis parameters are as follows:

[0043] The wollastonite used is from Luzhou, and its main chemical analysis parameters are as follows:

[0044] The quartz powder used is from Jiangxi Province, and its main chemical analysis control indicators are as follows:

[0045] Zirconium silicate using Huaan Zirconium silicate has the following key chemical control indicators:

[0046] The alumina used is Kaiyuan alumina, and its main chemical analysis control indicators are as follows:

[0047] The specific test data is as follows: Table 2 - Comparative experimental data before and after changes in microcline dosage

[0048] Table 3 - Comparative experimental results before and after changes in microcline dosage

[0049] As can be seen from Tables 2 and 3, changing the amount of microcline and albite will not only reduce the overall bending strength of the suspended porcelain, but also cause problems such as poor smoothness and pinholes.

[0050] Table 4 - Comparative experimental data before and after changes in calcined talc dosage

[0051] Table 5 - Comparative experimental results before and after changes in calcined talc dosage

[0052] As can be seen from Tables 4 and 5, both excessive and insufficient calcined talc content will result in insufficient high-temperature fluidity. Consequently, after glazing and sanding, the suspended porcelain will not only have a strength below 200 MPa and poor smoothness, but also, due to excessive calcined talc content, more and overlapping crystals will occur, resulting in a dull glaze and color difference.

[0053] Table 6 - Comparative experimental data before and after changes in wollastonite dosage

[0054] Table 7 - Comparative experimental results before and after changes in wollastonite dosage

[0055] As shown in Tables 6 and 7, when the wollastonite content is too low and the clay content is too high, the relative viscosity of the glaze is too high, while the high-temperature fluidity is too low, resulting in the suspended porcelain after firing being both rough and having pinholes. When the wollastonite content is too high, the relative viscosity decreases significantly and the high-temperature fluidity increases significantly, solving the problems of roughness and pinholes. However, this easily leads to glaze bubbles, which significantly reduces the wear resistance and corrosion resistance. Furthermore, the flexural strength of the suspended porcelain after firing can only reach a maximum of about 194 MPa, which does not break through the existing flexural strength of suspended porcelain.

[0056] Table 8 - Comparative experimental data before and after changes in quartz powder dosage

[0057] Table 9 - Comparative experimental results before and after changes in quartz powder dosage

[0058] As shown in Tables 8 and 9, when the quartz powder content is too low, the relative viscosity of the glaze increases, and the high-temperature fluidity at the lower firing position deteriorates, resulting in poor smoothness and flatness of the fired porcelain and the presence of pinholes. At the same time, the flexural strength cannot be improved. When the quartz powder content is too high and the clay content is too low, although the glaze surface of the umbrella part is smooth and flat, without pinholes, and has good wear and corrosion resistance, its flexural strength has just exceeded 200 MPa, and the flexural strength has not been significantly improved. In addition, due to the insufficient clay content, the glaze slurry suspension performance is poor, which affects the uniformity of the glaze in the glaze body and leads to color difference problems.

[0059] Table 10 - Comparative experimental data before and after changes in zirconium silicate dosage

[0060] Table 11 - Comparative experimental results before and after changes in zirconium silicate dosage

[0061] As shown in Tables 10 and 11, when the zirconium silicate content is too low, the relative viscosity of the glaze is too high and the high-temperature fluidity at the lower firing position is too low, resulting in suspended porcelain after firing, with problems such as strength of less than 200 MPa, pinholes, color difference, and poor wear resistance and corrosion resistance. When the zirconium silicate content is too high, although there is no color difference on the surface and the wear resistance and corrosion resistance are quite good, problems such as roughness, pinholes, and even glaze shrinkage occur, and the bending strength is also less than 210 MPa, making it impossible to achieve a breakthrough in bending strength.

[0062] It should be noted that due to the large amount of experimental data, not all results are presented. Through comparative research, it was found that controlling the alumina content between 2 and 6 parts per liter ensures minimal impact on the overall effect while keeping other components constant, guaranteeing the quality of the glaze and ensuring flexural strength. However, excessively low alumina content will reduce the glaze's effectiveness. of Hardness, but excessive use will reduce the high-temperature fluidity of the glaze. thereby This reduces the quality of the glaze.

[0063] Based on the experimental data above, it can be seen that the formula of this invention, through the control of the amounts of microcline, albite, Ordos clay, kaolin, calcined talc, wollastonite, quartz powder, zirconium silicate, and alumina, enables the glaze prepared under this formula to achieve a bending strength far exceeding that of existing technologies when applied to the blank. This allows the high-strength aluminum porcelain insulator to reach 220 MPa, or even 233.7 MPa, on top of the blank's bending strength of 170 MPa, after glazing and sanding, greatly improving the bending strength of the suspended porcelain after sanding. Furthermore, it allows for one-time glazing of the head umbrella during the first glazing of the blank, greatly simplifying the glazing process and reducing production costs for enterprises. In addition, the resulting suspended porcelain can also guarantee a smooth and flat surface, no color difference, and good wear resistance and corrosion resistance.

[0064] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A process for manufacturing glazed sand for ultra-high voltage porcelain insulators, characterized in that, Includes the following steps: I. Mix the glaze powder and porcelain sand evenly; II. While the porcelain sand and glaze powder are being stirred evenly, glue is added while stirring, so that the glue coats the glaze powder onto the porcelain sand, forming a layer of porcelain sand on the inside, glaze powder in the middle, and glaze glue on the outside. In step I, the mass ratio of porcelain sand to glaze powder is controlled at 1:(0.6-0.9). In step II, the amount of glue should be 1 / 4 to 1 / 3 of the amount of glaze powder. The fineness of the glaze powder is less than 80 micrometers, the porcelain sand is C130 porcelain with a particle size of 0.8 to 1.5 mm, and the particle size of the glaze-coating sand is 1.4 to 1.8 mm. After the glaze-coating sand is prepared, it is placed in a sealed container.

2. The glaze-coating sand manufacturing process for ultra-high voltage porcelain insulators according to claim 1, characterized in that: The glaze powder is prepared by grinding the following raw materials in parts by weight: 10-20 parts microcline, 10-20 parts sodium feldspar, 5-15 parts high plasticity clay, 7-12 parts kaolin, 10-14 parts calcined talc, 4-10 parts wollastonite, 15-25 parts quartz powder, 6-10 parts zirconium silicate, and 2-6 parts alumina.

3. The glaze-coating sand manufacturing process for ultra-high voltage porcelain insulators according to claim 2, characterized in that: The microcline is 10-18 parts and the albite is 12-20 parts.

4. The glaze-coating sand manufacturing process for ultra-high voltage porcelain insulators according to claim 2, characterized in that: The calcined talc is 10-12 parts.

5. The glaze-coating sand manufacturing process for ultra-high voltage porcelain insulators according to claim 2, characterized in that: The amount of quartz powder is 17-22 parts.

6. The glaze-coating sand manufacturing process for ultra-high voltage porcelain insulators according to claim 2, characterized in that: The chemical composition of the glaze powder includes: 60-72% SiO2, 14-17% Al2O3, less than 0.7% Fe2O3, 3-4% CaO, 3-5% MgO, 2-3.5% K2O, 1.5-3% Na2O, and 4-7% ZrO2.

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