High-strength rod-shaped porcelain insulator and preparation method thereof

Abstract

The invention provides a high-strength rod-shaped porcelain insulator and a preparation method thereof. The high-strength rod-shaped porcelain insulator is prepared from the following raw materials in parts by weight: 50 to 70 parts of alumina, 20 to 30 parts of feldspar powder, 10 to 20 parts of mullite powder, 20 to 40 parts of alumina powder, 5 to 20 parts of silicon dioxide micro powder, 5 to 15 parts of boron nitride powder, 10 to 20 parts of tourmaline powder, 5 to 10 parts of semi-carbonized straw fiber and 5 to 10 parts of diethyl succinate. The semi-carbonized straw fibers are obtained by carrying out pyrolysis treatment on straws under an anaerobic condition. The high-strength rod-shaped porcelain insulator provided by the invention has excellent strength performance, and can maintain relatively good working stability in atrocious weather.

Description

Technical Field

[0001] The invention relates to the technical field of insulators, and in particular to a high-strength rod-shaped porcelain insulator and a preparation method thereof. Background Art

[0002] As a special insulating control, insulators play a pivotal role in overhead transmission lines. In the early days, insulators were mainly used on utility poles, and then gradually developed to hang multi-disc insulators on high-voltage power line connection towers. These insulators are designed to increase creepage distances and are usually made of glass or ceramic materials, known as porcelain insulators. The design of insulators must ensure that they will not fail due to various electromechanical stresses caused by changes in environmental and electrical load conditions, otherwise they will not be able to play their key role, thereby damaging the use and operating life of the entire line. According to the different voltage levels used, insulators can be divided into two categories: low-voltage insulators and high-voltage insulators. High-voltage insulators are particularly suitable for high-voltage and ultra-high-voltage overhead transmission lines and substations. In order to meet the needs of different voltage levels, different numbers of single insulators of the same type are usually combined into insulator strings or multi-section insulating pillars. With the increasing complexity of environmental conditions, including severe climates such as ice and frost, and the destructive power of natural disasters such as earthquakes, high-voltage transmission lines have put forward higher requirements on the electrical and mechanical properties of column porcelain insulators. In 110KV to 330KV transmission lines, the mechanical strength level of the porcelain of the column porcelain insulator must reach more than 15KN, the bending strength requirement is between 180-200MPa, and the impact toughness must also meet high standards. However, the existing rod-shaped column porcelain insulators have low tensile strength and are easily damaged due to insufficient strength under harsh weather conditions, thus affecting the smooth operation of the transmission line. Summary of the invention

[0003] In view of this, the present invention proposes a high-strength rod-shaped porcelain insulator and a preparation method thereof to solve the above-mentioned problem.

[0004] The technical solution of the present invention is achieved as follows: a high-strength rod-shaped porcelain insulator comprises the following raw materials in parts by weight: 50-70 parts of alumina, 20-30 parts of feldspar powder, 10-20 parts of mullite powder, 20-40 parts of alumina powder, 5-20 parts of silicon dioxide powder, 5-15 parts of boron nitride powder, 10-20 parts of tourmaline powder, 5-10 parts of semi-carbonized straw fiber, 5-15 parts of black phosphorus powder, and 5-10 parts of diethyl succinate;

[0005] Among them, the semi-carbonized straw fiber is obtained by pyrolyzing the straw under anaerobic conditions.

[0006] Furthermore, semi-carbonized straw fiber is prepared by the following method: the straw is cleaned and then pretreated, and after the pretreatment, the straw is crushed to obtain short straw material, and then the short straw material is added to a pyrolysis device and pyrolyzed under anaerobic conditions, and after the pyrolysis is completed, it is cooled and collected to obtain semi-carbonized straw fiber.

[0007] Furthermore, the decomposition temperature is 325-330°C.

[0008] Furthermore, the straw pretreatment method is: adding the straw into a nitric acid aqueous solution and soaking it for 10-12 hours, and turning the straw over every 2.0-2.5 hours during the soaking process.

[0009] Furthermore, the mass concentration of the nitric acid aqueous solution is 50-60wt%.

[0010] Furthermore, the tourmaline powder is composed of magnesium tourmaline powder, iron tourmaline powder and chromium tourmaline powder in a mass ratio of (2.0-4.0):(1.0-2.5):(0.5-1.7).

[0011] Furthermore, the straw is one of wheat straw, corn straw, sesame straw and rice straw.

[0012] Furthermore, the method for preparing a high-strength rod-shaped porcelain insulator comprises the following steps:

[0013] S1. Weigh alumina, feldspar powder, mullite powder, alumina powder, silica powder, boron nitride powder, tourmaline powder, semi-carbonized straw fiber, black phosphorus powder and diethyl succinate in parts by weight, mix them, add water and grind them in a ball mill to form a slurry;

[0014] S2, pouring the slurry into a mold, and forming a blank of a rod-shaped porcelain insulator through a pressing process;

[0015] S3, immerse the blank into the glaze melt for 30-60s, put the blank into a gas-fired kiln for sintering after glazing, and after sintering, obtain a rod-shaped porcelain insulator through natural cooling.

[0016] Furthermore, in the pressing process in S2, the molding pressure is 50-100 MPa and the molding time is 15-25 min.

[0017] Furthermore, in S3, the sintering temperature is 1200-1400° C. and the sintering time is 12-18 h.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: semi-carbonized straw fibers are used in the raw materials of the insulators of the present application, and the semi-carbonized straw fibers retain part of the fiber morphology during the pyrolysis process. These fibers connect the ceramic particles like a "bridge", which enhances the bonding between the raw materials. During the pressing and sintering process, this bonding helps to reduce the formation of microcracks and pores, and improve the density and overall strength of the insulator. The flexibility of the semi-carbonized straw fibers enables it to absorb part of the energy when the insulator is impacted or bent, and disperse the stress through the stretching and deformation of the fibers, thereby improving the toughness and bending strength of the insulator.

[0019] The tourmaline powder used in this application plays a filling role in the insulator material, can fill the tiny pores and defects in the material, reduce the number of stress concentration points, improve the overall density and uniformity of the material, and then improve the mechanical strength of the insulator. The addition of boron nitride can also enhance the structural stability of the insulator material. Due to its good thermal stability and chemical stability, boron nitride can still maintain stable performance under high temperature, high pressure or corrosive environment, thereby ensuring the normal operation of the insulator under harsh working environment. Boron nitride and tourmaline powder also have a certain synergistic enhancement effect in the insulator material. The high hardness and wear resistance provided by boron nitride can be combined with the piezoelectric effect and filling effect of tourmaline powder to jointly improve the mechanical strength and durability of the insulator. In addition, boron nitride can also improve the dispersibility of tourmaline powder in the material to a certain extent, and improve the uniformity and density of the overall material. Then ensure that the porcelain insulator has good mechanical strength and product performance. In addition, by adding black phosphorus in this application, it is helpful to quickly export the heat inside the insulator to prevent breakdown caused by overheating, thereby improving the breakdown voltage of the insulator. DETAILED DESCRIPTION

[0020] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0021] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0022] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0023] Example 1

[0024] A high-strength rod-shaped porcelain insulator comprises the following raw materials in parts by weight: 50 parts of alumina, 20 parts of feldspar powder, 10 parts of mullite powder, 20 parts of alumina powder, 5 parts of silicon dioxide powder, 5 parts of boron nitride powder, 10 parts of tourmaline powder, 5 parts of semi-carbonized straw fiber, 5 parts of black phosphorus powder, and 5 parts of diethyl succinate. Among them, the semi-carbonized straw fiber is obtained by pyrolyzing the straw under anaerobic conditions. It is specifically prepared by the following method: the straw is washed and added to a nitric acid aqueous solution with a mass concentration of 50wt% and soaked for 12 hours for pretreatment, and the straw is turned over every 2.5 hours during the soaking process. After the pretreatment is completed, the straw is crushed to obtain short straw material, and then the short straw material is added to the pyrolysis equipment, and pyrolyzed under anaerobic conditions at a temperature of 325°C. After the pyrolysis is completed, it is cooled and collected to obtain the semi-carbonized straw fiber. The tourmaline powder is composed of magnesium tourmaline powder, iron tourmaline powder and chrome tourmaline powder in a mass ratio of 2.0:1.0:0.5. The straw is wheat straw.

[0025] The above-mentioned method for preparing a high-strength rod-shaped porcelain insulator comprises the following steps:

[0026] S1. Weigh alumina, feldspar powder, mullite powder, alumina powder, silica powder, boron nitride powder, tourmaline powder, semi-carbonized straw fiber, black phosphorus powder and diethyl succinate in parts by weight, mix them, add water and grind them in a ball mill to form a slurry;

[0027] S2, pouring the slurry into a mold, and forming a rod-shaped porcelain insulator blank through a pressing process, wherein the molding pressure is 50 MPa and the molding time is 25 minutes.

[0028] S3, immerse the green body in the glaze melt for 30 seconds, and then put the green body into a gas-fired kiln for sintering at 12000°C for 18 hours. After sintering, naturally cool the green body to obtain a rod-shaped porcelain insulator.

[0029] Example 2

[0030] A high-strength rod-shaped porcelain insulator comprises the following raw materials in parts by weight: 50 parts of alumina, 20 parts of feldspar powder, 10 parts of mullite powder, 20 parts of alumina powder, 5 parts of silicon dioxide powder, 5 parts of boron nitride powder, 10 parts of tourmaline powder, 5 parts of semi-carbonized straw fiber, 5 parts of black phosphorus powder, and 5 parts of diethyl succinate. Among them, the semi-carbonized straw fiber is obtained by pyrolysis of straw under anaerobic conditions. It is specifically prepared by the following method: the straw is washed and added to a nitric acid aqueous solution with a mass concentration of 60wt% and soaked for 102h for pretreatment, and the straw is turned over every 2.0h during the soaking process. After the pretreatment is completed, the straw is crushed to obtain short straw material, and then the short straw material is added to a pyrolysis device, and pyrolysis is carried out under anaerobic conditions at a temperature of 330°C. After the pyrolysis is completed, it is cooled and collected to obtain the semi-carbonized straw fiber. The tourmaline powder is composed of magnesium tourmaline powder, iron tourmaline powder and chrome tourmaline powder in a mass ratio of 4.0:2.5:0.5. The straw is corn straw.

[0031] The above-mentioned method for preparing a high-strength rod-shaped porcelain insulator comprises the following steps:

[0032] S1. Weigh alumina, feldspar powder, mullite powder, alumina powder, silica powder, boron nitride powder, tourmaline powder, semi-carbonized straw fiber, black phosphorus powder and diethyl succinate in parts by weight, mix them, add water and grind them in a ball mill to form a slurry;

[0033] S2. Pour the slurry into a mold and form a rod-shaped porcelain insulator blank through a pressing process, wherein the molding pressure is 100 MPa and the molding time is 155 min.

[0034] S3, immerse the green body in the glaze melt for 60 seconds, and then put the green body into a gas-fired kiln for sintering at 1400°C for 12 hours. After sintering, naturally cool the green body to obtain a rod-shaped porcelain insulator.

[0035] Example 3

[0036] A high-strength rod-shaped porcelain insulator includes the following raw materials by weight: 60 parts of alumina, 25 parts of feldspar powder, 15 parts of mullite powder, 30 parts of alumina powder, 12 parts of silicon dioxide powder, 10 parts of boron nitride powder, 15 parts of tourmaline powder, 8 parts of semi-carbonized straw fiber, 10 parts of black phosphorus powder, and 7 parts of diethyl succinate. Among them, the semi-carbonized straw fiber is obtained by pyrolysis of straw under anaerobic conditions. It is specifically prepared by the following method: the straw is washed and added to a nitric acid aqueous solution with a mass concentration of 55wt% and soaked for 11 hours for pretreatment, and the straw is turned over every 2.2 hours during the soaking process. After the pretreatment is completed, the straw is crushed to obtain short straw material, and then the short straw material is added to a pyrolysis device, and pyrolysis is carried out under anaerobic conditions at a temperature of 327.5°C. After the pyrolysis is completed, it is cooled and collected to obtain the semi-carbonized straw fiber. The tourmaline powder is composed of magnesium tourmaline powder, iron tourmaline powder and chrome tourmaline powder in a mass ratio of 3.0:1.8:1.1. The straw is sesame straw.

[0037] The above-mentioned method for preparing a high-strength rod-shaped porcelain insulator comprises the following steps:

[0038] S1. Weigh alumina, feldspar powder, mullite powder, alumina powder, silica powder, boron nitride powder, tourmaline powder, semi-carbonized straw fiber, black phosphorus powder and diethyl succinate in parts by weight, mix them, add water and grind them in a ball mill to form a slurry;

[0039] S2. Pour the slurry into a mold and form a rod-shaped porcelain insulator blank through a pressing process, wherein the molding pressure is 75 MPa and the molding time is 20 minutes.

[0040] S3, immerse the green body in the glaze melt for 45 seconds, and then put the green body into a gas-fired kiln for sintering at 1300°C for 15 hours. After sintering, naturally cool the green body to obtain a rod-shaped porcelain insulator.

[0041] Example 4

[0042] A high-strength rod-shaped porcelain insulator comprises the following raw materials in parts by weight: 70 parts of alumina, 30 parts of feldspar powder, 20 parts of mullite powder, 40 parts of alumina powder, 20 parts of silicon dioxide powder, 15 parts of boron nitride powder, 20 parts of tourmaline powder, 10 parts of semi-carbonized straw fiber, 15 parts of black phosphorus powder, and 10 parts of diethyl succinate. Among them, the semi-carbonized straw fiber is obtained by pyrolyzing the straw under anaerobic conditions. It is specifically prepared by the following method: the straw is washed and added to a nitric acid aqueous solution with a mass concentration of 50wt% and soaked for 12 hours for pretreatment, and the straw is turned over every 2.5 hours during the soaking process. After the pretreatment is completed, the straw is crushed to obtain short straw material, and then the short straw material is added to the pyrolysis equipment, and pyrolyzed under anaerobic conditions at a temperature of 325°C. After the pyrolysis is completed, it is cooled and collected to obtain the semi-carbonized straw fiber. The tourmaline powder is composed of magnesium tourmaline powder, iron tourmaline powder and chrome tourmaline powder in a mass ratio of 2.0:1.0:0.5. The straw is rice straw.

[0043] The above-mentioned method for preparing a high-strength rod-shaped porcelain insulator comprises the following steps:

[0044] S1. Weigh alumina, feldspar powder, mullite powder, alumina powder, silica powder, boron nitride powder, tourmaline powder, semi-carbonized straw fiber, black phosphorus powder and diethyl succinate in parts by weight, mix them, add water and grind them in a ball mill to form a slurry;

[0045] S2, pouring the slurry into a mold, and forming a rod-shaped porcelain insulator blank through a pressing process, wherein the molding pressure is 50 MPa and the molding time is 25 minutes.

[0046] S3, immerse the green body in the glaze melt for 30 seconds, and then put the green body into a gas-fired kiln for sintering at 1200°C for 18 hours. After sintering, naturally cool the green body to obtain a rod-shaped porcelain insulator.

[0047] Example 5

[0048] A high-strength rod-shaped porcelain insulator comprises the following raw materials in parts by weight: 70 parts of alumina, 30 parts of feldspar powder, 120 parts of mullite powder, 40 parts of alumina powder, 20 parts of silicon dioxide powder, 15 parts of boron nitride powder, 20 parts of tourmaline powder, 10 parts of semi-carbonized straw fiber, 15 parts of black phosphorus powder, and 10 parts of diethyl succinate. Among them, the semi-carbonized straw fiber is obtained by pyrolysis of straw under anaerobic conditions. It is specifically prepared by the following method: the straw is washed and added to a nitric acid aqueous solution with a mass concentration of 60wt% and soaked for 10 hours for pretreatment, and the straw is turned over every 2.0 hours during the soaking process. After the pretreatment is completed, the straw is crushed to obtain short straw material, and then the short straw material is added to a pyrolysis device, and pyrolysis is carried out under anaerobic conditions at a temperature of 330°C. After the pyrolysis is completed, it is cooled and collected to obtain the semi-carbonized straw fiber. The tourmaline powder is composed of magnesium tourmaline powder, iron tourmaline powder and chrome tourmaline powder in a mass ratio of 4.0:2.5:1.7. The straw is wheat straw.

[0049] The above-mentioned method for preparing a high-strength rod-shaped porcelain insulator comprises the following steps:

[0050] S1. Weigh alumina, feldspar powder, mullite powder, alumina powder, silica powder, boron nitride powder, tourmaline powder, semi-carbonized straw fiber, black phosphorus powder and diethyl succinate in parts by weight, mix them, add water and grind them in a ball mill to form a slurry;

[0051] S2. Pour the slurry into a mold and form a rod-shaped porcelain insulator blank through a pressing process, wherein the molding pressure is 100 MPa and the molding time is 15 minutes.

[0052] S3, immerse the green body in the glaze melt for 60 seconds, and then put the green body into a gas-fired kiln for sintering at 1400°C for 12 hours. After sintering, naturally cool the green body to obtain a rod-shaped porcelain insulator.

[0053] Comparative Example 1

[0054] The difference between this comparative example and Example 3 is that an equal amount of boron nitride powder is used instead of tourmaline powder.

[0055] Comparative Example 2

[0056] The difference between this comparative example and Example 3 is that an equal amount of tourmaline powder is used instead of boron nitride powder.

[0057] Comparative Example 3

[0058] The difference between this comparative example and Example 3 is that wheat straw fibers in equal parts by weight are used instead of semi-carbonized straw fibers.

[0059] Comparative Example 4

[0060] The difference between this comparative example and Example 3 is that the raw materials do not contain black phosphorus powder.

[0061] Performance Testing

[0062] The bending strength of the test samples prepared by the methods described in the above embodiments and comparative examples was tested with reference to the requirements of standard GB / T 4741-1999, and the loading speed was set to 20 N / s; the breakdown voltage of the test samples prepared by the methods described in the above embodiments and comparative examples was tested by using an impulse voltage generator to simulate the lightning strike effect; each group of test samples was repeatedly frozen and thawed 30 times at -50°C to 40°C, first the sample was placed in a box at a constant temperature of -50°C and allowed to stand for 20 minutes, then taken out and allowed to stand in the air for 10 minutes, then the sample was placed in a box at a constant temperature of 40°C and allowed to stand for 20 minutes, and after the standing was completed, it was taken out and allowed to stand in the air for 10 minutes, that is, one freeze-thaw process was completed, and whether cracks were generated on the surface of the sample after 30 freeze-thaw cycles, the results are shown in Table 1.

[0063] Bending strength / N Impulse voltage / kV Is there any crack after 30 freeze-thaw cycles? Example 1 525 175 No cracks Example 2 527 174 No cracks Example 3 533 180 No cracks Example 4 526 175 No cracks Example 5 528 173 No cracks Comparative Example 1 263 116 A few cracks Comparative Example 2 272 127 A few cracks Comparative Example 3 413 131 A few cracks Comparative Example 4 315 128 A few cracks

[0064] The flexural strength of the porcelain insulator of embodiment 1-5 is within the range of 525-533MPa, which is much higher than the 180-200MPa required by the traditional insulator, and the breakdown voltage is also relatively high, maintained at 173-180kV. This is mainly due to the synergistic effect of semi-carbonized straw fiber, black phosphorus powder, tourmaline powder and boron nitride powder. Semi-carbonized straw fiber enhances the cohesiveness and toughness between raw materials, black phosphorus powder can promote the densification of ceramic raw materials during sintering, thereby improving the density and strength of the product, and tourmaline powder and boron nitride powder improve the overall strength and stability of the insulator through the filling effect and their own high hardness and wear resistance.

[0065] After replacing tourmaline powder with boron nitride powder in Comparative Example 1, both the flexural strength and breakdown voltage decreased significantly. This indicates that the piezoelectric effect and filling effect of tourmaline powder have important contributions to the performance of the insulator, and boron nitride powder alone cannot completely replace it.

[0066] In Comparative Example 2, when tourmaline powder completely replaced boron nitride powder, the performance also decreased, but the decrease was smaller than that in Comparative Example 1. This shows that the high hardness and chemical stability of boron nitride powder also have a positive effect on the performance of insulators, but the role of tourmaline powder is more critical.

[0067] Examples 1-5 all exhibited excellent freeze-thaw resistance without cracks, which was due to the flexibility and toughening effect of the semi-carbonized straw fibers, as well as the high density and uniformity of the overall material.

[0068] A small amount of cracks appeared in both comparative examples 1 and 2, indicating that the synergistic effect of tourmaline powder and boron nitride powder is crucial to improving the freeze-thaw resistance of the insulator.

[0069] The insulator performance of Examples 1-5 using semi-carbonized straw fiber is significantly better than that of Comparative Example 3, mainly because the organic components in the straw are partially carbonized after treatment, which not only retains the fiber morphology of part of the straw, but also gives it new physical and chemical properties. The semi-carbonization treatment significantly improves the flexibility, adhesion and thermal stability of the straw fiber, thereby enhancing the overall performance of the insulator. Although the wheat straw fiber in Comparative Example 3 also has a certain strengthening effect, its performance is still far behind that of the semi-carbonized straw fiber.

[0070] Examples 1-5 are superior to Comparative Example 4 in terms of bending strength, breakdown voltage and freeze-thaw resistance. This is because black phosphorus powder can form an effective reinforcement phase. When the insulator is subjected to bending stress, the black phosphorus powder particles can effectively bear part of the stress, thereby delaying the expansion of cracks and improving the bending strength of the porcelain insulator. In the insulator, the addition of black phosphorus powder can increase the thickness and uniformity of the insulator's electrical insulation layer, thereby improving the insulator's breakdown voltage. When the insulator is subjected to high voltage, the black phosphorus powder particles can form barriers to prevent the current from breaking through the inside of the porcelain insulator. In addition, the addition of black phosphorus powder can improve the microstructure of the insulator and increase the porosity and specific surface area inside the insulator. These pores and specific surface area are conducive to the penetration and discharge of water molecules. When the insulator is subjected to freeze-thaw cycles, the black phosphorus powder particles can absorb and release water molecules, thereby reducing the damage to the insulator caused by water expansion and contraction. At the same time, black phosphorus powder has good thermal stability and is not prone to phase change or decomposition due to temperature changes. In insulators, the addition of black phosphorus powder can improve the overall thermal stability of the insulator, enabling it to maintain good performance under extreme temperature conditions.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength rod-shaped porcelain insulator, characterized in that: The invention comprises the following raw materials in parts by weight: 50-70 parts of alumina, 20-30 parts of feldspar powder, 10-20 parts of mullite powder, 20-40 parts of alumina powder, 5-20 parts of silicon dioxide powder, 5-15 parts of boron nitride powder, 10-20 parts of tourmaline powder, 5-10 parts of semi-carbonized straw fiber, 5-15 parts of black phosphorus powder, and 5-10 parts of diethyl succinate; The semi-carbonized straw fiber is obtained by pyrolyzing the straw under anaerobic conditions.

2. A high-strength rod-shaped porcelain insulator as claimed in claim 1, characterized in that: The semi-carbonized straw fiber is prepared by the following method: washing the straw and then pre-treating it, breaking the straw after the pre-treatment to obtain short straw material, then adding the short straw material into a pyrolysis device, pyrolyzing it under anaerobic conditions, and collecting the semi-carbonized straw fiber after cooling after the pyrolysis is completed.

3. A high-strength rod-shaped porcelain insulator as claimed in claim 2, characterized in that: The pyrolysis temperature is 325-330°C.

4. A high-strength rod-shaped porcelain insulator as claimed in claim 3, characterized in that: The straw pretreatment method is: adding the straw into a nitric acid aqueous solution and soaking it for 10-12 hours, and turning the straw over every 2.0-2.5 hours during the soaking process.

5. A high-strength rod-shaped porcelain insulator as claimed in claim 4, characterized in that: The mass concentration of the nitric acid aqueous solution is 50-60wt%.

6. A high-strength rod-shaped porcelain insulator as claimed in claim 1, characterized in that: The tourmaline powder is composed of magnesium tourmaline powder, iron tourmaline powder and chromium tourmaline powder in a mass ratio of (2.0-4.0):(1.0-2.5):(0.5-1.7).

7. A high-strength rod-shaped porcelain insulator as claimed in claim 1, characterized in that: The straw is one of wheat straw, corn straw, sesame straw and rice straw.

8. The method for preparing a high-strength rod-shaped porcelain insulator according to claim 1, characterized in that: The following steps are involved: S1. Weigh alumina, feldspar powder, mullite powder, alumina powder, silica powder, boron nitride powder, tourmaline powder, semi-carbonized straw fiber, black phosphorus powder and diethyl succinate in parts by weight, mix them, add water and grind them in a ball mill to form a slurry; S2, pouring the slurry into a mold, and forming a blank of a rod-shaped porcelain insulator through a pressing molding process; S3, immerse the blank into the glaze melt for 30-60s, put the blank into a gas-fired kiln for sintering after glazing, and after sintering, obtain a rod-shaped porcelain insulator through natural cooling.

9. The method for preparing a high-strength rod-shaped porcelain insulator according to claim 8, characterized in that: The pressing process in S2 has a molding pressure of 50-100 MPa and a molding time of 15-25 min.

10. The method for preparing a high-strength rod-shaped porcelain insulator according to claim 8, characterized in that: In the S3, the sintering temperature is 1200-1400° C. and the sintering time is 12-18 hours.