A method for manufacturing a high-strength ceramic insulator

Abstract

The application relates to the technical field of ceramics, in particular to a preparation method of a high-strength ceramic insulator. The preparation method comprises the following steps: preparing modified corundum powder by discharging plasma ball milling of corundum and fluorotantalum powder and fluoroniobium powder; mixing and ball milling the modified corundum powder, feldspar, titanium oxide, wollastonite, magnesia clay and the like to prepare a mud; and preparing the high-strength ceramic insulator through pressure filtration, aging, shaping and sintering. By introducing fluorotantalum powder and fluoroniobium powder and adopting the discharging plasma ball milling technology, the compactness, the bulk density and the microstructure uniformity of the ceramic are remarkably improved, the porosity and the water absorption are reduced, and the bending strength and the anti-pollution flashover capacity are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramics, in particular to a preparation method of high-strength ceramic insulator. BACKGROUND

[0002] As a key component in power transmission lines and electrical equipment, ceramic insulators are widely used in high-voltage power transmission, substations and electrical equipment. Its main function is to support the wire and isolate the electrical connection between the wire and the grounding structure. With the development of modern power systems towards high voltage and large capacity, ceramic insulators need to have higher mechanical strength, insulation performance and anti-flashover ability to meet the use requirements in complex working conditions and harsh environments. However, the traditional ceramic insulator still has certain limitations in performance, which is difficult to fully meet the use requirements in high-strength and high-pollution environments.

[0003] Traditional high-strength ceramic insulators are usually made of corundum as the main raw material, supplemented by other additives. Although corundum-based ceramics have high mechanical strength and excellent insulation performance, the compactness and uniformity of the internal structure still need to be improved. The pores and micro-cracks in the material not only reduce the bulk density and mechanical strength, but also cause the water absorption rate to rise, thereby affecting the insulation performance, especially in harsh environments such as high humidity or rain and snow, which is prone to insulation failure. In addition, the traditional ceramic insulator is easy to adsorb pollutants in a high-pollution environment, which intensifies the surface electric field concentration effect, thereby causing a flashover accident, which seriously threatens the safe operation of the power system. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a preparation method of high-strength ceramic insulator, which significantly improves the comprehensive performance of ceramic insulator by introducing functional additives and optimizing the preparation process, to meet the use requirements in high-strength and high-pollution environments.

[0005] Based on the above purpose, the present application provides a preparation method of high-strength ceramic insulator, comprising the following steps:

[0006] (1) Raw material treatment: grinding corundum with a ball mill through a 200-mesh sieve, and then performing discharge plasma ball milling with tantalum fluoride powder and niobium fluoride powder to obtain modified corundum powder;

[0007] (2) Powder mixing: mixing the modified corundum powder, feldspar, titanium oxide, wollastonite and magnesia clay, and then putting them into a ball mill, adding deionized water, and ball milling through an 80-120 mesh sieve to obtain crude mud;

[0008] (3) Pressure filtration and aging: putting the crude mud into a pressure filter, and then aging to obtain refined mud;

[0009] (4) Molding of the refined clay: the refined clay is put into a molding mold, molded, dried, and a clay blank is obtained;

[0010] (5) Sintering of the clay blank: the clay blank is put into a sintering furnace, sintered, and a high-strength ceramic insulator is obtained.

[0011] Preferably, the weight ratio of corundum, tantalum fluoride powder and niobium fluoride powder in step (1) is 1000:40-60:20-40.

[0012] Preferably, the ball-to-material weight ratio in the step (1) of the ball milling is 15-30:1, the discharge frequency is 20-40 KHz, the rotating speed is 1500-2500 rpm, and the time is 4-6 h.

[0013] Preferably, the weight ratio of the modified corundum powder, feldspar, titanium oxide, wollastonite and magnesia clay in step (2) is 700-800:100-150:40-75:35-60:80-120.

[0014] Preferably, the amount of the deionized water added in step (2) is equal to the total weight of the modified corundum powder, feldspar, titanium oxide, wollastonite and magnesia clay.

[0015] Preferably, the silica content of the feldspar in step (2) is 67wt%-68wt%.

[0016] Preferably, the magnesium oxide content of the magnesia clay is 25wt%-27wt%.

[0017] Preferably, the ball-to-material ratio in step (2) of the ball milling is 20-40:1.

[0018] Preferably, the working pressure of the pressure filtration in step (3) is 0.5-0.7 MPa, the pressure filtration time is 1.5-2.5 h, and the aging time is 20-28 h.

[0019] Preferably, the molding pressure in step (4) is 20-30 MPa.

[0020] Preferably, the sintering in step (5) is: heating at 4-6 ℃ / min to 900-1100 ℃, then heating at 1-3 ℃ / min to 1350-1450 ℃, and keeping the temperature for 2-4 h.

[0021] The beneficial effects of the present application are:

[0022] This invention provides a method for preparing high-strength ceramic insulators, which exhibit significant advantages in mechanical and insulation properties. The material possesses a high bulk density and extremely low open porosity, with a water absorption rate of less than 0.1%. Its flexural strength exceeds 180 MPa, far surpassing the performance requirements of traditional high-strength aluminum ceramic insulators. This demonstrates higher load-bearing capacity and resistance to mechanical impact, meeting the demands of complex working conditions and high strength requirements. Simultaneously, the material exhibits excellent resistance to flashover, effectively reducing the occurrence of flashover accidents and improving the reliability and service life of the insulators.

[0023] This invention significantly improves the bulk density, flexural strength, and flashover resistance of ceramic insulators by introducing niobium fluoride and tantalum fluoride powders. Niobium fluoride and tantalum fluoride powders enhance surface hydrophobicity, optimize microstructure, and reduce surface defects and electric field concentration effects, thereby improving flashover resistance. The niobium fluoride and tantalum fluoride powders are refined to nanoscale and uniformly dispersed using spark plasma ball milling technology, forming a strong bonding interface with the corundum matrix. This further improves the material's density and stress transfer capacity between particles, significantly enhancing flexural strength and flashover resistance. Furthermore, the addition of magnesia clay promotes sintering densification, reduces internal porosity, and enhances grain bonding, thereby increasing bulk density and mechanical strength. The ceramic insulators prepared by this invention exhibit excellent performance under high-strength and high-pollution environments, showing broad application prospects. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0025] Example 1:

[0026] (1) Raw material processing: 1000g of corundum was ground through a 200-mesh sieve using a ball mill, and then mixed with 40g of tantalum fluoride powder and 20g of niobium fluoride powder by discharge plasma ball milling. The ball-to-material weight ratio was 15:1, the discharge frequency was 20KHz, the rotation speed was 1500rpm, and the time was 4h to obtain modified corundum powder.

[0027] (2) Powder mixing: Mix 700g of modified corundum powder, 100g of feldspar, 40g of titanium dioxide, 35g of wollastonite and 80g of magnesia clay, put them into a ball mill with a ball-to-material ratio of 20:1, add 955g of deionized water, and ball mill through an 80-mesh sieve to obtain coarse mud.

[0028] (3) Filter press aging: Put the coarse mud into the filter press, the working pressure is 0.5MPa, the filter press time is 1.5h, and then age it for 20h to obtain refined mud;

[0029] (4) Molding of the clay: The refined clay is put into a molding mold, the molding pressure is 20 MPa, and then dried at 75°C for 20 h to obtain a clay blank;

[0030] (5) Sintering of the clay blank: The clay blank is put into a sintering furnace, heated to 900°C at a rate of 4°C / min, then heated to 1350°C at a rate of 1°C / min, and kept for 2 h to obtain a high-strength ceramic insulator.

[0031] Example 2:

[0032] (1) Treatment of raw materials: 1000 g of corundum is ground to pass through a 200 mesh sieve using a ball mill, and then subjected to discharge plasma ball milling with 50 g of tantalum fluoride powder and 30 g of niobium fluoride powder, the ball-to-material weight ratio being 20:1, the discharge frequency being 30 KHz, the rotation speed being 2000 rpm, and the time being 5 h to obtain modified corundum powder;

[0033] (2) Mixing of powders: 750 g of the modified corundum powder, 120 g of feldspar, 60 g of titanium oxide, 50 g of wollastonite, and 100 g of magnesia clay are mixed, put into a ball mill, the ball-to-material ratio being 30:1, 1080 g of deionized water is added, and then ground to pass through a 100 mesh sieve to obtain crude clay;

[0034] (3) Pressure filtration and aging: the crude clay is put into a pressure filter, the working pressure is 0.6 MPa, the pressure filtration time is 2 h, and then aging is performed, the aging time being 24 h to obtain refined clay;

[0035] (4) Molding of the clay: The refined clay is put into a molding mold, the molding pressure is 25 MPa, and then dried at 80°C for 24 h to obtain a clay blank;

[0036] (5) Sintering of the clay blank: The clay blank is put into a sintering furnace, heated to 1000°C at a rate of 5°C / min, then heated to 1400°C at a rate of 2°C / min, and kept for 3 h to obtain a high-strength ceramic insulator.

[0037] Example 3:

[0038] (1) Treatment of raw materials: 1000 g of corundum is ground to pass through a 200 mesh sieve using a ball mill, and then subjected to discharge plasma ball milling with 60 g of tantalum fluoride powder and 40 g of niobium fluoride powder, the ball-to-material weight ratio being 30:1, the discharge frequency being 40 KHz, the rotation speed being 2500 rpm, and the time being 6 h to obtain modified corundum powder;

[0039] (2) Mixing of powders: 800 g of the modified corundum powder, 150 g of feldspar, 75 g of titanium oxide, 60 g of wollastonite, and 120 g of magnesia clay are mixed, put into a ball mill, the ball-to-material ratio being 40:1, 1205 g of deionized water is added, and then ground to pass through a 120 mesh sieve to obtain crude clay;

[0040] (3) Filter pressing and aging: the crude mud is put into a filter press, the working pressure is 0.7 MPa, the filter pressing time is 2.5 h, and then aging is performed, the aging time is 28 h, to obtain refined mud;

[0041] (4) Mud forming: the refined mud is put into a forming mold, the forming pressure is 30 MPa, and then drying is performed at 85℃ for 28 h, to obtain a green body;

[0042] (5) Green body sintering: the green body is put into a sintering furnace, the temperature is raised to 1100℃ at a rate of 6℃ / min, then the temperature is raised to 1450℃ at a rate of 3℃ / min, and the temperature is kept for 4 h, to obtain a high-strength ceramic insulator.

[0043] Comparative Example 1:

[0044] The difference between Comparative Example 1 and Example 2 is that the tantalum fluoride powder in step (1) is replaced by niobium fluoride powder;

[0045] The specific steps are as follows:

[0046] (1) Raw material treatment: 1000g of corundum is ground through a 200 mesh sieve using a ball mill, and then is subjected to electric discharge plasma ball milling with 80g of tantalum fluoride powder, the ball-to-material weight ratio is 20:1, the electric discharge frequency is 30KHz, the rotation speed is 2000rpm, and the time is 5h, to obtain modified corundum powder;

[0047] (2) Powder mixing: 750g of modified corundum powder, 120g of feldspar, 60g of titanium oxide, 50g of wollastonite and 100g of magnesia clay are mixed, put into a ball mill, the ball-to-material ratio is 30:1, then 1080g of deionized water is added, and the mixture is ground through a 100 mesh sieve, to obtain crude mud;

[0048] (3) Filter pressing and aging: the crude mud is put into a filter press, the working pressure is 0.6 MPa, the filter pressing time is 2h, and then aging is performed, the aging time is 24 h, to obtain refined mud;

[0049] (4) Mud forming: the refined mud is put into a forming mold, the forming pressure is 25 MPa, and then drying is performed at 80℃ for 24 h, to obtain a green body;

[0050] (5) Green body sintering: the green body is put into a sintering furnace, the temperature is raised to 1000℃ at a rate of 5℃ / min, then the temperature is raised to 1400℃ at a rate of 2℃ / min, and the temperature is kept for 3 h, to obtain a ceramic insulator.

[0051] Comparative Example 2:

[0052] The difference between Comparative Example 2 and Example 2 is that the tantalum fluoride powder in step (1) is replaced by niobium fluoride powder;

[0053] The specific steps are as follows:

[0054] (1) Raw material treatment: 1000 g of corundum was ground by a ball mill to pass through a 200 mesh sieve, and then was subjected to a discharge plasma ball milling with 80 g of niobium fluoride powder, the ball-to-material weight ratio was 20:1, the discharge frequency was 30 KHz, the rotating speed was 2000 rpm, and the time was 5 h, to obtain modified corundum powder;

[0055] (2) Powder mixing: 750 g of the modified corundum powder, 120 g of feldspar, 60 g of titanium oxide, 50 g of wollastonite and 100 g of magnesia clay were mixed, and then were put into a ball mill, the ball-to-material ratio was 30:1, 1080 g of deionized water was further added, and then was ground to pass through a 100 mesh sieve, to obtain a crude body;

[0056] (3) Pressure filtration and aging: the crude body was put into a pressure filter, the working pressure was 0.6 MPa, the pressure filtration time was 2 h, and then was subjected to aging, the aging time was 24 h, to obtain a refined body;

[0057] (4) Body shaping: the refined body was put into a shaping mold, the shaping pressure was 25 MPa, and then was dried at 80℃ for 24 h, to obtain a green body;

[0058] (5) Body sintering: the green body was put into a sintering furnace, and then was heated to 1000℃ at a rate of 5℃ / min, and then was heated to 1400℃ at a rate of 2℃ / min, and was kept for 3 h, to obtain a ceramic insulator.

[0059] Comparative Example 3:

[0060] The difference between Comparative Example 3 and Example 2 is that the modified corundum powder in step (2) is replaced by a mixture of corundum powder ground to pass through a 200 mesh sieve, tantalum fluoride powder and niobium fluoride powder;

[0061] The specific steps are as follows:

[0062] (1) Raw material treatment: 1000 g of corundum was ground by a ball mill to pass through a 200 mesh sieve, and then was mixed with 50 g of tantalum fluoride powder and 30 g of niobium fluoride powder, to obtain a mixed powder;

[0063] (2) Powder mixing: 750 g of the mixed powder, 120 g of feldspar, 60 g of titanium oxide, 50 g of wollastonite and 100 g of magnesia clay were mixed, and then were put into a ball mill, the ball-to-material ratio was 30:1, 1080 g of deionized water was further added, and then was ground to pass through a 100 mesh sieve, to obtain a crude body;

[0064] (3) Pressure filtration and aging: the crude body was put into a pressure filter, the working pressure was 0.6 MPa, the pressure filtration time was 2 h, and then was subjected to aging, the aging time was 24 h, to obtain a refined body;

[0065] (4) Molding of the refined clay: the refined clay was put into a molding mold, the molding pressure was 25 MPa, and then dried at 80°C for 24 h to obtain a green body;

[0066] (4) Sintering of the green body: the green body was put into a sintering furnace, heated to 1000°C at a rate of 5°C / min, then heated to 1400°C at a rate of 2°C / min, and kept for 3 h to obtain a high-strength ceramic insulator.

[0067] Comparative Example 4:

[0068] Comparative Example 4 differs from Example 2 in that the modified corundum powder in step (2) is replaced by corundum powder ball-milled through a 200-mesh sieve;

[0069] The specific steps are as follows:

[0070] (1) Powder mixing: 750 g of corundum powder ball-milled through a 200-mesh sieve, 120 g of feldspar, 60 g of titanium oxide, 50 g of wollastonite, and 100 g of magnesia clay were mixed, put into a ball mill, the ball-to-material ratio was 30:1, 1080 g of deionized water was added, and ball-milling was performed through a 100-mesh sieve to obtain a crude clay;

[0071] (2) Pressure filtration and aging: the crude clay was put into a pressure filter, the working pressure was 0.6 MPa, the pressure filtration time was 2 h, and then aging was performed, the aging time was 24 h to obtain a refined clay;

[0072] (3) Molding of the refined clay: the refined clay was put into a molding mold, the molding pressure was 25 MPa, and then dried at 80°C for 24 h to obtain a green body;

[0073] (4) Sintering of the green body: the green body was put into a sintering furnace, heated to 1000°C at a rate of 5°C / min, then heated to 1400°C at a rate of 2°C / min, and kept for 3 h to obtain a ceramic insulator.

[0074] Comparative Example 5:

[0075] Comparative Example 5 differs from Example 2 in that no magnesia clay was added in step (2);

[0076] The specific steps are as follows:

[0077] (1) Raw material treatment: 1000 g of corundum was ground through a 200-mesh sieve using a ball mill, and then subjected to discharge plasma ball-milling with 50 g of tantalum fluoride powder and 30 g of niobium fluoride powder, the ball-to-material weight ratio was 20:1, the discharge frequency was 30 KHz, the rotation speed was 2000 rpm, and the time was 5 h to obtain a modified corundum powder;

[0078] (2) Powder mixing: 750 g of modified corundum powder, 120 g of feldspar, 60 g of titanium oxide and 50 g of wollastonite were mixed, put into a ball mill, the ball-to-material ratio was 30:1, 1080 g of deionized water was further added, and the mixture was ball milled to pass through a 100 mesh sieve to obtain a crude body;

[0079] (3) Filter pressing and aging: the crude body was put into a filter press, the working pressure was 0.6 MPa, the filter pressing time was 2 h, and then aging was performed, the aging time was 24 h, to obtain a refined body;

[0080] (4) Body forming: the refined body was put into a forming mold, the forming pressure was 25 MPa, and then drying was performed at 80℃ for 24 h to obtain a green body;

[0081] (5) Body sintering: the green body was put into a sintering furnace, heated to 1000℃ at a rate of 5℃ / min, then heated to 1400℃ at a rate of 2℃ / min, and kept for 3 h to obtain a ceramic insulator.

[0082] Performance test:

[0083] Bulk density, open porosity and water absorption: the drainage method in GB / T 2997-2000 was used for testing, and the results are shown in Table 1;

[0084] Bending strength: according to GB / T 6569-2006, a hydraulic universal testing machine was used for testing, and the results are shown in Table 1.

[0085] Pollution flashover test: a salt solution with a concentration of 0.0036 mg / ml of NaCl was prepared, 0.216 g of diatomite was added to the salt solution, and stirred to prepare a pollution solution, the solvent was deionized water, the surface of the insulator prepared in the examples and the comparative examples was pasted with aluminum foil to form a pollution area with a size of 12 mm x 15 mm (the distance between the aluminum foil electrodes was 12 mm, and the width was 15 mm), the area was 1.8 cm 2 , a drop of pollution solution was dropped on the area using a 1 ml dropper, and the pollution solution was evenly coated in the set pollution area using the dropper, then the contaminated sample was transferred to a blast drying oven for drying to evaporate the surface solvent. After drying, the three samples were fixed on an angle table with an inclination angle of 60°, the water mist generator was turned on, the input rate of the water mist was controlled at 380 mL / h, and the water mist was continuously blown against the surface of the sample for 1 h. After the surface was completely wet, the sample was placed in the test device to test the pollution flashover voltage, and the dry flashover voltage of the sample without pollution was tested, and the voltage drop rate after pollution flashover was calculated, and the results are shown in Table 1.

[0086] Table 1 Performance test results

[0087]

[0088] Data analysis:

[0089] From the data of examples 1-3 in table 1, it can be seen that the high-strength ceramic insulator prepared by the present application has significant advantages in mechanical properties and insulation performance. The large bulk density and extremely low open porosity indicate that the internal structure of the material is dense, reducing the adverse effects of pores on strength and insulation performance, thereby significantly improving the mechanical strength and durability of the material. The water absorption of less than 0.1% further proves the denseness and excellent water immersion resistance of the material, which is crucial for the stable operation of the insulator in harsh environments such as high humidity or rain and snow. In addition, the bending strength reaches more than 180 MPa, far exceeding the performance requirements of C130 high-strength aluminum ceramic insulators, indicating that the ceramic insulator of the present application has higher load-carrying capacity and mechanical impact resistance, and can meet the use requirements of higher strength and more complex working conditions. At the same time, its certain anti-flashover capacity indicates that the material surface has good anti-pollution performance and insulation stability, which can effectively reduce the occurrence of flashover accidents and improve the reliability and service life of the insulator.

[0090] From the data of examples 2 and comparative examples 1-3 in table 1, it can be seen that the introduction of niobium fluoride powder and tantalum fluoride powder into corundum by spark plasma ball milling can synergistically improve the bulk density of the ceramic insulator, reduce the porosity and water absorption, and have a significant effect on the improvement of the bending strength. This is mainly due to the fact that spark plasma ball milling can uniformly disperse and refine the niobium fluoride powder and tantalum fluoride powder to nano-sized particles, and the high energy introduced during the ball milling process can promote the activation of the particle surface, enabling it to tightly combine with the corundum particles and promote the formation of a more dense microstructure with other raw materials, significantly improving the bulk density of the ceramic material, reducing the number and size of pores, and thus reducing the porosity and water absorption. In addition, the high energy generated during the spark plasma ball milling process can also promote the interfacial reaction between the niobium fluoride and tantalum fluoride particles and the corundum matrix, forming a strong interfacial bond. This interfacial bond not only improves the overall denseness of the material, but also enhances the stress transfer ability between particles, thereby significantly improving the bending strength of the ceramic insulator.

[0091] As can be seen from the data of Example 2 and Comparative Examples 3-4 in Table 1, the direct mixing of niobium fluoride powder and tantalum fluoride powder into the raw materials of the ceramic insulator can improve the anti-pollution flashover ability of the ceramic insulator, which is mainly due to the fact that the niobium fluoride powder and tantalum fluoride powder can improve the anti-pollution flashover ability by enhancing the surface hydrophobicity, optimizing the microstructure, reducing the surface defects and electric field concentration effect. Moreover, the introduction of the niobium fluoride powder and tantalum fluoride powder into corundum by the discharge plasma ball milling and then mixing with the remaining raw materials can further improve the anti-pollution flashover ability, which is probably due to the fact that the high energy generated in the ball milling process promotes the interfacial reaction between the niobium fluoride, tantalum fluoride particles and the corundum matrix, forming a firmly bonded interface. This interface bonding reduces the microcracks and pores inside the material, further reducing the surface defects and electric field concentration effect.

[0092] As can be seen from the data of Example 2 and Comparative Example 5 in Table 1, the addition of magnesia clay into the raw materials of the ceramic insulator can effectively improve the bulk density and bending strength of the ceramic insulator, which is mainly due to the fact that the magnesia clay can promote the rearrangement and densification of ceramic particles during high-temperature sintering, reducing the porosity inside the material, thereby improving the bulk density and mechanical strength.

[0093] It should be understood by those skilled in the art that the above discussion of any of the embodiments is merely exemplary and is not intended to suggest that the scope of the application is limited to these examples; under the concept of the application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the application as described above. In order to be brief, they are not provided in details.

Claims

1. A method for preparing a high-strength ceramic insulator, characterized in that, Includes the following steps: (1) Raw material processing: Corundum is ground through a 200-mesh sieve using a ball mill, and then subjected to spark plasma ball milling with tantalum fluoride powder and niobium fluoride powder to obtain modified corundum powder. (2) Powder mixing: Mix modified corundum powder, feldspar, titanium dioxide, wollastonite and magnesia clay, put them into a ball mill, add deionized water, and ball mill through an 80-120 mesh sieve to obtain coarse mud. (3) Filter press aging: Put the coarse mud into a filter press and then age it to obtain refined mud; (4) Clay molding: The refined clay is placed into the molding mold, shaped, and dried to obtain a clay blank; (5) Sintering of clay blanks: The clay blanks are placed in a firing furnace and sintered to obtain high-strength ceramic insulators; In step (1), the weight ratio of corundum, tantalum fluoride powder and niobium fluoride powder is 1000:40-60:20-40.

2. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, In step (1), the ball-to-material weight ratio of the discharge plasma ball mill is 15-30:1, the discharge frequency is 20-40KHz, the rotation speed is 1500-2500rpm, and the time is 4-6h.

3. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, In step (2), the weight ratio of modified corundum powder, feldspar, titanium dioxide, wollastonite and magnesian clay is 700-800:100-150:40-75:35-60:80-120.

4. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, In step (2), the amount of deionized water added is equal to the total weight of modified corundum powder, feldspar, titanium dioxide, wollastonite and magnesian clay.

5. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, In step (2), the silica content of feldspar is 67wt%-68wt%.

6. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, The magnesium oxide content in the magnesian clay is 25wt%-27wt%.

7. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, In step (2), the ball-to-material ratio in ball milling is 20-40:

1.

8. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, In step (3), the working pressure of the filter press is 0.5-0.7 MPa, the filter press time is 1.5-2.5 h, and the aging time is 20-28 h.

9. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, The molding pressure in step (4) is 20-30 MPa.

10. The method for preparing a high-strength ceramic insulator according to claim 1, characterized in that, The sintering in step (5) is as follows: the temperature is increased to 900-1100℃ at 4-6℃ / min, and then increased to 1350-1450℃ at 1-3℃ / min, and held for 2-4 hours.

Images