CN116639960B - Preparation method of high-strength porcelain insulator - Google Patents

Abstract

The invention discloses a preparation method of a high-strength porcelain insulator, which comprises the following steps: (1) preparing modified powder; (2) preparing Si-Zr composite oxide; (3) preparing carbon-attached alumina powder; (4) Uniformly mixing the modified powder, si-Zr composite oxide, carbon-attached alumina powder, magnesia powder, potassium feldspar and clay to form a mixed material, carrying out wet ball milling on the mixed material, removing iron after ball milling, adjusting the water content to 23-25 wt%, pressing into a blank, drying the blank for more than 40 hours at the temperature of 100-110 ℃, heating to 450-500 ℃ at the temperature of 10 ℃/min, calcining for 1-2 hours, heating to 1250-1280 ℃ at the temperature of 5 ℃/min, sintering for 3-4 hours, cooling to 300 ℃ at the temperature of 5 ℃/min, and air-cooling to normal temperature to obtain the high-strength porcelain insulator. The porcelain insulator material prepared by the method has good mechanical strength and insulativity.

Description

A method for preparing high-strength porcelain insulator

Technical Field

The invention relates to the technical field of insulator materials, and in particular to a method for preparing a high-strength porcelain insulator.

Background Art

Suspension porcelain insulators are divided into porcelain insulators, composite insulators and glass insulators according to different materials. Porcelain insulators are traditional insulators. They have experienced a development history of more than 100 years from research and development to the present. Their products have developed from ordinary 35kV and below voltage levels to the world's highest 1100kV ultra-high voltage level. The working environment and working conditions of insulator products are extremely harsh, and they are affected by factors such as sudden changes in temperature, extreme heat, severe cold, high pH, and high pollution. During operation, insulator products must not only withstand the power frequency voltage under normal operating conditions, but also withstand the transient overvoltage caused by lightning strikes under severe weather conditions; not only must they withstand the weight of the conductor, but also withstand the test of extreme factors such as the icing state of the conductor and the violent swing of the conductor under the action of wind; under the combined effect of the above conditions, insulator products will produce dielectric degradation under long-term working voltage and workload, that is, the performance of insulator products will decrease with the extension of service time, and finally lead to product degradation. In order to ensure the stability of the performance of insulator products and enable them to operate effectively, the industry has put forward very strict performance requirements for insulator products, mainly including electrical, mechanical, and thermal insulation.

Summary of the invention

To this end, the present invention provides a method for preparing a high-strength porcelain insulator, comprising the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, an ethanol solution of n-butyl titanate is prepared, the ethanol solution of n-butyl titanate is stirred, the mixed solution is added to the solution during the stirring process, glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, the solution is stirred for more than 20 minutes, and the solution is aged at room temperature for more than 70 hours after the addition of the mixed solution is completed, and then the solution is concentrated under reduced pressure, the solid-liquid separation is carried out, and the solid phase is calcined at 500-530° C. for 2-3 hours to obtain a powder solid phase A; barium hydroxide is added to deionized water in a reactor, and the water bath is kept at a constant temperature of 90±2° C. so that the barium hydroxide is completely dissolved to obtain a barium hydroxide aqueous solution, and the barium hydroxide aqueous solution is stirred at a constant temperature of 90±2° C., and the powder solid phase is added to the solution during the stirring process, and the reactor is closed after the addition of the mixed solution is completed, and the reactor is heated to 140-160° C. and kept warm for more than 10 hours, and then air-cooled to room temperature, and the reactor is opened, the solid-liquid separation is carried out, and the solid phase is washed with deionized water and dried to obtain the modified powder;

(2) Preparation of Si-Zr composite oxide: preparing an ethanol solution of poloxamer F-127 as an active liquid, adding hydrochloric acid and glacial acetic acid to the active liquid, stirring the active liquid for 20 to 30 minutes after the addition is completed, then adding tetraethyl orthosilicate and zirconium n-butoxide to the active liquid under stirring, stirring for more than 2 hours after the addition is completed, and keeping the active liquid in a water bath at a constant temperature of 70±3°C for more than 20 hours after stirring, then separating the solid from the liquid, and calcining the solid phase at 450 to 480°C for 1 to 2 hours to obtain the Si-Zr composite oxide;

(3) preparing an aqueous solution of glucose, immersing α-alumina in the aqueous solution of glucose to obtain a suspension, placing the suspension in a vacuum box, maintaining pressure at 0.01 standard atmospheric pressure for more than 30 minutes, maintaining heat in a water bath at 80±5° C. for more than 30 minutes after the pressure maintenance, then separating the solid and the liquid, and drying the solid phase at 120° C. for more than 2 hours to obtain alumina powder with glucose adhered to the surface, placing the alumina powder with glucose adhered to the surface in a nitrogen atmosphere, heating to 800-820° C., maintaining heat for more than 5 hours, and obtaining carbon-attached alumina powder;

(4) The modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, the mixture is wet-milled, iron is removed after ball milling, the water content is adjusted to 23-25wt%, and the mixture is pressed into a blank, the blank is dried at 100-110° C. for more than 40 h, then heated to 450-500° C. at 10° C./min and calcined for 1-2 h, then heated to 1250-1280° C. at 5° C./min and sintered for 3-4 h, then cooled to 300° C. at 5° C./min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator.

Furthermore, in the step (1), the mass ratio of the ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:1-2; the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 16%-20%; the volume ratio of the mixed solution and glacial acetic acid added to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:1-2:0.4-0.6.

Furthermore, in the aqueous solution of barium hydroxide, the concentration of barium hydroxide is 2-3 mmol/L, and the solid-liquid mass ratio of the powder solid phase A added to the aqueous solution of barium hydroxide is powder solid phase A: aqueous solution of barium hydroxide = 1:8.

Furthermore, in the ethanol solution of poloxamer F-127, the concentration of poloxamer F-127 is 4.5-4.8 g/100 mL, and the solvent is ethanol; the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:1-2:3-5, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; the volume ratio of the added mass of tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 is tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 1.8-2.8 g: 3-5 g: 50 mL.

Furthermore, in step (3), the concentration of glucose in the aqueous solution of glucose is 15-20 g/100 mL, and the solvent is water; the solid-liquid mass ratio of the suspension obtained by immersing α-alumina in the aqueous solution of glucose is solid/liquid = 1:5.

Furthermore, in the step (4), the modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, which is calculated by weight as follows: 3 to 8 parts of modified powder, 6 to 8 parts of Si-Zr composite oxide, 20 to 25 parts of carbon-attached alumina powder, 4 to 6 parts of magnesium oxide powder, 12 to 16 parts of potassium feldspar and 14 to 20 parts of clay.

The mechanism of the technical solution of the present invention is as follows: the present invention first prepares a rare earth doped modified powder raw material, and after adding the porcelain insulator raw material, the rare earth is beneficial to inhibit the growth of the alumina matrix grains during the sintering process, avoids the generation of coarse crystals, and plays a certain role in fine grain strengthening. Then, by generating a barium titanate layer on the surface of the modified powder, the characteristic that barium titanate and the alumina matrix easily form a eutectic phase is utilized. During the sintering process, the generation of the eutectic phase can improve the interfacial bonding force between the modified powder and the alumina matrix on the one hand, and on the other hand, the liquid phase has a certain fluidity and can penetrate into the defects of the ceramic matrix, reducing the amount of defects and holes, thereby improving the strength and density of the ceramic. By adding Si-Zr composite oxide, the zirconium phase in the composite oxide is easy to entangle with the alumina matrix to form an interpenetrating network structure, making the overall structure of the ceramic finer to improve the mechanical properties and insulation of the material. The silicon phase in the composite oxide is easy to form Si-C melt with the carbon on the surface of the carbon-attached alumina powder during the sintering process. In the subsequent cooling process, fine SiC particles are precipitated at the grain boundaries, which can effectively hinder the growth of the matrix grains and play a second phase strengthening effect.

The beneficial effects of the present invention are as follows: the porcelain insulator material prepared by the method of the present invention has good mechanical strength and insulation, is suitable for the bracket installation of high-voltage transmission lines with large insulator load requirements and high voltage, and improves the safety of the transmission lines.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with the embodiments.

Example 1

A method for preparing a high-strength porcelain insulator comprises the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:1; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 16%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process, and glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, and the volume ratio of the mixed solution and glacial acetic acid to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:1:0.4; after the addition is completed, the solution is stirred for 20 minutes, aged at room temperature for 70 hours after the stirring is completed, and then concentrated under reduced pressure to a concentrated 1/3 of the volume before shrinkage, solid-liquid separation, solid phase calcined at 500°C for 3h to obtain powder solid phase A; barium hydroxide is added to deionized water in a reactor, and the water bath is kept at a constant temperature of 90±2°C so that the barium hydroxide is completely dissolved to obtain an aqueous solution of barium hydroxide, in which the concentration of barium hydroxide is 2mmol/L, and the aqueous solution of barium hydroxide is stirred at a constant temperature of 90±2°C. During the stirring process, the powder solid phase is added to the solution, and the solid-liquid mass ratio of the powder solid phase A added to the aqueous solution of barium hydroxide is powder solid phase A: barium hydroxide aqueous solution = 1:8; after the addition is completed, the reactor is closed, heated to 150°C for 10h, and then air-cooled to room temperature, the reactor is opened, the solid-liquid separation is performed, the solid phase is washed with deionized water, and dried to obtain the modified powder;

(2) Preparation of Si-Zr composite oxide: an ethanol solution of poloxamer F-127 is prepared as an active liquid, wherein the concentration of poloxamer F-127 in the ethanol solution is 4.5 g/100 mL, and the solvent is ethanol; hydrochloric acid and glacial acetic acid are added to the active liquid, and the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:1:3, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; after the addition is completed, the active liquid is stirred and the mixture is stirred for 3 hours. The active solution was stirred for 20 minutes, and then tetraethyl orthosilicate and zirconium n-butoxide were added to the active solution under stirring, wherein the added mass ratio of the tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 was tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 1.8 g: 3 g: 50 mL; after the addition was completed, the active solution was stirred for 2 hours, and after stirring, the active solution was kept at a constant temperature of 70±3° C. in a water bath for 20 hours, and then the solid-liquid was separated, and the solid phase was calcined at 450° C. for 2 hours to obtain the Si-Zr composite oxide;

(3) preparing an aqueous solution of glucose, wherein the concentration of glucose in the aqueous solution of glucose is 15 g/100 mL and the solvent is water; immersing α-alumina in the aqueous solution of glucose to obtain a suspension, wherein the solid-liquid mass ratio of the suspension obtained by immersing α-alumina in the aqueous solution of glucose is solid/liquid=1:5; placing the suspension in a vacuum box, maintaining the pressure at 0.01 standard atmospheric pressure for 30 minutes, and then maintaining the pressure in a water bath at 80±5°C for 30 minutes, then separating the solid and the liquid, and drying the solid phase at 120°C for 2 hours to obtain an alumina powder with glucose adhered to the surface, and placing the alumina powder with glucose adhered to the surface in a nitrogen atmosphere, heating it to 800°C, and maintaining the heat for 5 hours to obtain carbon-attached alumina powder;

(4) The modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the weight proportion of each component (all powders passing through a 300-mesh sieve) is as follows: 3 parts of modified powder, 6 parts of Si-Zr composite oxide, 20 parts of carbon-attached alumina powder, 4 parts of magnesium oxide powder, 12 parts of potassium feldspar and 14 parts of clay; the mixture is wet-milled using a planetary ball mill, and the mass ratio of ball to material to water is ball: material: water = 2:1 :1; the ball milling speed is 100r/min, the ball milling time is 8h, the iron is removed after ball milling, the water content is adjusted to 25wt%, and the insulator blank and the sample blank are pressed. The insulator blank and the sample blank are dried at 110°C for 40h, then heated to 450°C at 10°C/min and calcined for 1h, then heated to 1260°C at 5°C/min and sintered for 3h, then cooled to 300°C at 5°C/min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator and test sample.

Example 2

A method for preparing a high-strength porcelain insulator comprises the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:1; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 18%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process, and glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, and the volume ratio of the mixed solution and glacial acetic acid to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:1:0.5; after the addition is completed, the solution is stirred for 20 minutes, aged at room temperature for 70 hours after the stirring is completed, and then concentrated under reduced pressure to a concentrated 1/3 of the volume before shrinkage, solid-liquid separation, solid phase calcined at 500°C for 3h to obtain powder solid phase A; barium hydroxide is added to deionized water in a reactor, and the water bath is kept at a constant temperature of 90±2°C so that the barium hydroxide is completely dissolved to obtain an aqueous solution of barium hydroxide, in which the concentration of barium hydroxide is 2mmol/L, and the aqueous solution of barium hydroxide is stirred at a constant temperature of 90±2°C. During the stirring process, the powder solid phase is added to the solution, and the solid-liquid mass ratio of the powder solid phase A added to the aqueous solution of barium hydroxide is powder solid phase A: barium hydroxide aqueous solution = 1:8; after the addition is completed, the reactor is closed, heated to 150°C for 10h, and then air-cooled to room temperature, the reactor is opened, the solid-liquid separation is performed, the solid phase is washed with deionized water, and dried to obtain the modified powder;

(2) Preparation of Si-Zr composite oxide: an ethanol solution of poloxamer F-127 is prepared as an active liquid, wherein the concentration of poloxamer F-127 in the ethanol solution is 4.6 g/100 mL, and the solvent is ethanol; hydrochloric acid and glacial acetic acid are added to the active liquid, and the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:1:4, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; after the addition is completed, the active liquid is stirred and the mixture is stirred for 3 hours. The active solution was stirred for 20 minutes, and then tetraethyl orthosilicate and zirconium n-butoxide were added to the active solution under stirring, wherein the volume ratio of the added mass of the tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 was tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 2.2 g: 4 g: 50 mL; after the addition was completed, the active solution was stirred for 2 hours, and after stirring, the active solution was kept at a constant temperature of 70±3° C. in a water bath for 20 hours, and then the solid-liquid was separated, and the solid phase was calcined at 450° C. for 2 hours to obtain the Si-Zr composite oxide;

(3) preparing an aqueous solution of glucose, wherein the concentration of glucose in the aqueous solution of glucose is 18 g/100 mL and the solvent is water; immersing α-alumina in the aqueous solution of glucose to obtain a suspension, wherein the solid-liquid mass ratio of the suspension obtained by immersing α-alumina in the aqueous solution of glucose is solid/liquid=1:5; placing the suspension in a vacuum box, maintaining the pressure at 0.01 standard atmospheric pressure for 30 minutes, and then maintaining the pressure in a water bath at 80±5°C for 30 minutes, then separating the solid and the liquid, and drying the solid phase at 120°C for 2 hours to obtain an alumina powder with glucose adhered to the surface, and placing the alumina powder with glucose adhered to the surface in a nitrogen atmosphere, heating it to 800°C, and maintaining the heat for 5 hours to obtain carbon-attached alumina powder;

(4) The modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the weight proportion of each component (all powders passing through a 300-mesh sieve) is as follows: 5 parts of modified powder, 7 parts of Si-Zr composite oxide, 22 parts of carbon-attached alumina powder, 5 parts of magnesium oxide powder, 14 parts of potassium feldspar and 16 parts of clay; the mixture is wet-milled using a planetary ball mill, and the mass ratio of ball to material to water is ball: material: water = 2:1 :1; the ball milling speed is 100r/min, the ball milling time is 8h, the iron is removed after ball milling, the water content is adjusted to 25wt%, and the insulator blank and the sample blank are pressed. The insulator blank and the sample blank are dried at 110°C for 40h, then heated to 450°C at 10°C/min and calcined for 1h, then heated to 1260°C at 5°C/min and sintered for 3h, then cooled to 300°C at 5°C/min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator and test sample.

Example 3

A method for preparing a high-strength porcelain insulator comprises the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:2; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 18%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process, and glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, and the volume ratio of the mixed solution and glacial acetic acid to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:2:0.5; after the addition is completed, the solution is stirred for 20 minutes, aged at room temperature for 70 hours after the stirring is completed, and then concentrated under reduced pressure to a concentrated 1/3 of the volume before shrinkage, solid-liquid separation, solid phase calcined at 530°C for 2h to obtain powder solid phase A; barium hydroxide is added to deionized water in a reactor, and the water bath is kept at a constant temperature of 90±2°C so that the barium hydroxide is completely dissolved to obtain an aqueous solution of barium hydroxide, in which the concentration of barium hydroxide is 3mmol/L, and the aqueous solution of barium hydroxide is stirred at a constant temperature of 90±2°C, and the powder solid phase is added to the solution during stirring, and the solid-liquid mass ratio of powder solid phase A added to the aqueous solution of barium hydroxide is powder solid phase A: barium hydroxide aqueous solution = 1:8; after the addition is completed, the reactor is closed, heated to 150°C for 10h, and then air-cooled to room temperature, the reactor is opened, solid-liquid separation is performed, the solid phase is washed with deionized water, and dried to obtain the modified powder;

(2) Preparation of Si-Zr composite oxide: an ethanol solution of poloxamer F-127 is prepared as an active liquid, wherein the concentration of poloxamer F-127 in the ethanol solution is 4.7 g/100 mL, and the solvent is ethanol; hydrochloric acid and glacial acetic acid are added to the active liquid, and the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:2:4, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; after the addition is completed, the active liquid is stirred and the mixture is stirred for 3 hours. The active solution was stirred for 20 minutes, and then tetraethyl orthosilicate and zirconium n-butoxide were added to the active solution under stirring, wherein the added mass ratio of the tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 was tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 2.4 g: 4 g: 50 mL; after the addition was completed, the active solution was stirred for 2 hours, and after stirring, the active solution was kept at a constant temperature of 70±3° C. in a water bath for 20 hours, and then the solid-liquid separation was carried out, and the solid phase was calcined at 480° C. for 1 hour to obtain the Si-Zr composite oxide;

(3) preparing an aqueous solution of glucose, wherein the concentration of glucose in the aqueous solution of glucose is 18 g/100 mL and the solvent is water; immersing α-alumina in the aqueous solution of glucose to obtain a suspension, wherein the solid-liquid mass ratio of the suspension obtained by immersing α-alumina in the aqueous solution of glucose is solid/liquid=1:5; placing the suspension in a vacuum box, maintaining the pressure at 0.01 standard atmospheric pressure for 30 minutes, and then maintaining the pressure in a water bath at 80±5°C for 30 minutes, then separating the solid and the liquid, and drying the solid phase at 120°C for 2 hours to obtain an alumina powder with glucose adhered to the surface, and placing the alumina powder with glucose adhered to the surface in a nitrogen atmosphere, heating it to 800°C, and maintaining the heat for 5 hours to obtain carbon-attached alumina powder;

(4) The modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the weight proportion of each component (all powders passing through a 300-mesh sieve) is as follows: 7 parts of modified powder, 7 parts of Si-Zr composite oxide, 23 parts of carbon-attached alumina powder, 5 parts of magnesium oxide powder, 14 parts of potassium feldspar and 18 parts of clay; the mixture is wet-milled using a planetary ball mill, and the mass ratio of ball to material to water is ball: material: water = 2:1 :1; the ball milling speed is 100r/min, the ball milling time is 8h, the iron is removed after ball milling, the water content is adjusted to 25wt%, and the insulator blank and the sample blank are pressed. The insulator blank and the sample blank are dried at 110°C for 40h, then heated to 450°C at 10°C/min and calcined for 1h, then heated to 1260°C at 5°C/min and sintered for 3h, then cooled to 300°C at 5°C/min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator and test sample.

Example 4

A method for preparing a high-strength porcelain insulator comprises the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:2; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 20%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process, and glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, and the volume ratio of the mixed solution and glacial acetic acid to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:2:0.6; after the addition is completed, the solution is stirred for 20 minutes, aged at room temperature for 70 hours after the stirring is completed, and then concentrated under reduced pressure to a concentrated 1/3 of the volume before shrinkage, solid-liquid separation, solid phase calcined at 530°C for 2h to obtain powder solid phase A; barium hydroxide is added to deionized water in a reactor, and the water bath is kept at a constant temperature of 90±2°C so that the barium hydroxide is completely dissolved to obtain an aqueous solution of barium hydroxide, in which the concentration of barium hydroxide is 3mmol/L, and the aqueous solution of barium hydroxide is stirred at a constant temperature of 90±2°C, and the powder solid phase is added to the solution during stirring, and the solid-liquid mass ratio of powder solid phase A added to the aqueous solution of barium hydroxide is powder solid phase A: barium hydroxide aqueous solution = 1:8; after the addition is completed, the reactor is closed, heated to 150°C for 10h, and then air-cooled to room temperature, the reactor is opened, solid-liquid separation is performed, the solid phase is washed with deionized water, and dried to obtain the modified powder;

(2) Preparation of Si-Zr composite oxide: an ethanol solution of poloxamer F-127 is prepared as an active liquid, wherein the concentration of poloxamer F-127 in the ethanol solution is 4.8 g/100 mL, and the solvent is ethanol; hydrochloric acid and glacial acetic acid are added to the active liquid, and the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:2:5, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; after the addition is completed, the active liquid is stirred and the mixture is stirred for 3 hours. The active solution was stirred for 20 minutes, and then tetraethyl orthosilicate and zirconium n-butoxide were added to the active solution under stirring, wherein the added mass ratio of the tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 was tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 2.8 g: 5 g: 50 mL; after the addition was completed, the active solution was stirred for 2 hours, and after stirring, the active solution was kept at a constant temperature of 70±3° C. in a water bath for 20 hours, and then the solid-liquid separation was carried out, and the solid phase was calcined at 480° C. for 1 hour to obtain the Si-Zr composite oxide;

(3) preparing an aqueous solution of glucose, wherein the concentration of glucose in the aqueous solution of glucose is 20 g/100 mL and the solvent is water; immersing α-alumina in the aqueous solution of glucose to obtain a suspension, wherein the solid-liquid mass ratio of the suspension obtained by immersing α-alumina in the aqueous solution of glucose is solid/liquid=1:5; placing the suspension in a vacuum box, maintaining the pressure at 0.01 standard atmospheric pressure for 30 minutes, and then maintaining the pressure in a water bath at 80±5°C for 30 minutes, then separating the solid and the liquid, and drying the solid phase at 120°C for 2 hours to obtain an alumina powder with glucose adhered to the surface, and placing the alumina powder with glucose adhered to the surface in a nitrogen atmosphere, heating it to 800°C, and maintaining the temperature for 5 hours to obtain carbon-attached alumina powder;

(4) The modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the weight proportion of each component (all powders passing through a 300-mesh sieve) is as follows: 8 parts of modified powder, 8 parts of Si-Zr composite oxide, 25 parts of carbon-attached alumina powder, 6 parts of magnesium oxide powder, 16 parts of potassium feldspar and 20 parts of clay; the mixture is wet-milled using a planetary ball mill, and the mass ratio of ball to material to water is ball: material: water = 2:1 :1; the ball milling speed is 100r/min, the ball milling time is 8h, the iron is removed after ball milling, the water content is adjusted to 25wt%, and the insulator blank and the sample blank are pressed. The insulator blank and the sample blank are dried at 110°C for 40h, then heated to 450°C at 10°C/min and calcined for 1h, then heated to 1260°C at 5°C/min and sintered for 3h, then cooled to 300°C at 5°C/min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator and test sample.

Comparative Example 1

A method for preparing a porcelain insulator as a comparison comprises the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:2; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 18%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process. After the addition of the mixed solution is completed, glacial acetic acid is added to the solution under stirring, and the volume ratio of the mixed solution and glacial acetic acid is added to the ethanol solution of n-butyl titanate: mixed solution: glacial acetic acid = 2:2:0.5; after the addition is completed, the solution is stirred for 20 minutes, aged at room temperature for 70 hours, and then concentrated under reduced pressure to 1/3 of the volume before concentration, solid-liquid separation is performed, and the solid phase is calcined at 530° C. for 2 hours to obtain a powder solid phase A, which is used as the modified powder described in this comparative example;

(2) Preparation of Si-Zr composite oxide: an ethanol solution of poloxamer F-127 is prepared as an active liquid, wherein the concentration of poloxamer F-127 in the ethanol solution is 4.7 g/100 mL, and the solvent is ethanol; hydrochloric acid and glacial acetic acid are added to the active liquid, and the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:2:4, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; after the addition is completed, the active liquid is stirred and the mixture is stirred for 3 hours. The active solution was stirred for 20 minutes, and then tetraethyl orthosilicate and zirconium n-butoxide were added to the active solution under stirring, wherein the added mass ratio of the tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 was tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 2.4 g: 4 g: 50 mL; after the addition was completed, the active solution was stirred for 2 hours, and after stirring, the active solution was kept at a constant temperature of 70±3° C. in a water bath for 20 hours, and then the solid-liquid separation was carried out, and the solid phase was calcined at 480° C. for 1 hour to obtain the Si-Zr composite oxide;

(3) preparing an aqueous solution of glucose, wherein the concentration of glucose in the aqueous solution of glucose is 18 g/100 mL and the solvent is water; immersing α-alumina in the aqueous solution of glucose to obtain a suspension, wherein the solid-liquid mass ratio of the suspension obtained by immersing α-alumina in the aqueous solution of glucose is solid/liquid=1:5; placing the suspension in a vacuum box, maintaining the pressure at 0.01 standard atmospheric pressure for 30 minutes, and then maintaining the pressure in a water bath at 80±5°C for 30 minutes, then separating the solid and the liquid, and drying the solid phase at 120°C for 2 hours to obtain an alumina powder with glucose adhered to the surface, and placing the alumina powder with glucose adhered to the surface in a nitrogen atmosphere, heating it to 800°C, and maintaining the heat for 5 hours to obtain carbon-attached alumina powder;

(4) The modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the weight proportion of each component (all powders passing through a 300-mesh sieve) is as follows: 7 parts of modified powder, 7 parts of Si-Zr composite oxide, 23 parts of carbon-attached alumina powder, 5 parts of magnesium oxide powder, 14 parts of potassium feldspar and 18 parts of clay; the mixture is wet-milled using a planetary ball mill, and the mass ratio of ball to material to water is ball: material: water = 2:1:1 The ball milling speed is 100r/min, the ball milling time is 8h, the iron is removed after ball milling, the water content is adjusted to 25wt%, and the insulator blank and the sample blank are pressed. The insulator blank and the sample blank are dried at 110°C for 40h, then heated to 450°C at 10°C/min and calcined for 1h, then heated to 1260°C at 5°C/min and sintered for 3h, then cooled to 300°C at 5°C/min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator and test sample described in this comparative example.

Comparative Example 2

A method for preparing a porcelain insulator as a comparison comprises the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:2; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 18%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process, and glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, and the volume ratio of the mixed solution and glacial acetic acid to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:2:0.5; after the addition is completed, the solution is stirred for 20 minutes, aged at room temperature for 70 hours after the stirring is completed, and then concentrated under reduced pressure to a concentrated 1/3 of the volume before shrinkage, solid-liquid separation, solid phase calcined at 530°C for 2h to obtain powder solid phase A; barium hydroxide is added to deionized water in a reactor, and the water bath is kept at a constant temperature of 90±2°C so that the barium hydroxide is completely dissolved to obtain an aqueous solution of barium hydroxide, in which the concentration of barium hydroxide is 3mmol/L, and the aqueous solution of barium hydroxide is stirred at a constant temperature of 90±2°C, and the powder solid phase is added to the solution during stirring, and the solid-liquid mass ratio of powder solid phase A added to the aqueous solution of barium hydroxide is powder solid phase A: barium hydroxide aqueous solution = 1:8; after the addition is completed, the reactor is closed, heated to 150°C for 10h, and then air-cooled to room temperature, the reactor is opened, solid-liquid separation is performed, the solid phase is washed with deionized water, and dried to obtain the modified powder;

(2) preparing an aqueous solution of glucose, wherein the concentration of glucose in the aqueous solution of glucose is 18 g/100 mL and the solvent is water; immersing α-alumina in the aqueous solution of glucose to obtain a suspension, wherein the solid-liquid mass ratio of the suspension obtained by immersing α-alumina in the aqueous solution of glucose is solid/liquid=1:5; placing the suspension in a vacuum box, maintaining the pressure at 0.01 standard atmospheric pressure for 30 minutes, and then maintaining the pressure in a water bath at 80±5°C for 30 minutes, then separating the solid and the liquid, and drying the solid phase at 120°C for 2 hours to obtain an alumina powder with glucose adhered to the surface, and placing the alumina powder with glucose adhered to the surface in a nitrogen atmosphere, heating it to 800°C, and maintaining the heat for 5 hours to obtain carbon-attached alumina powder;

(3) The modified powder, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the weight proportion of each component (all powders passing through a 300-mesh sieve) is as follows: 7 parts of modified powder, 23 parts of carbon-attached alumina powder, 5 parts of magnesium oxide powder, 14 parts of potassium feldspar and 18 parts of clay; the mixture is wet-milled using a planetary ball mill, and the mass ratio of ball to material to water is ball: material: water = 2:1:1; the ball milling speed is 100 r/m in, the ball milling time is 8h, iron is removed after ball milling, the water content is adjusted to 25wt%, and the insulator blank and the sample blank are pressed. The insulator blank and the sample blank are dried at 110°C for 40h, then heated to 450°C at 10°C/min and calcined for 1h, then heated to 1260°C at 5°C/min and sintered for 3h, then cooled to 300°C at 5°C/min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator and test sample described in this comparative example.

Comparative Example 3

A method for preparing a porcelain insulator as a comparison comprises the following steps:

(1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:2; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 18%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process, and glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, and the volume ratio of the mixed solution and glacial acetic acid to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:2:0.5; after the addition is completed, the solution is stirred for 20 minutes, aged at room temperature for 70 hours after the stirring is completed, and then concentrated under reduced pressure to a concentrated 1/3 of the volume before shrinkage, solid-liquid separation, solid phase calcined at 530°C for 2h to obtain powder solid phase A; barium hydroxide is added to deionized water in a reactor, and the water bath is kept at a constant temperature of 90±2°C so that the barium hydroxide is completely dissolved to obtain an aqueous solution of barium hydroxide, in which the concentration of barium hydroxide is 3mmol/L, and the aqueous solution of barium hydroxide is stirred at a constant temperature of 90±2°C, and the powder solid phase is added to the solution during stirring, and the solid-liquid mass ratio of powder solid phase A added to the aqueous solution of barium hydroxide is powder solid phase A: barium hydroxide aqueous solution = 1:8; after the addition is completed, the reactor is closed, heated to 150°C for 10h, and then air-cooled to room temperature, the reactor is opened, solid-liquid separation is performed, the solid phase is washed with deionized water, and dried to obtain the modified powder;

(2) Preparation of Si-Zr composite oxide: an ethanol solution of poloxamer F-127 is prepared as an active liquid, wherein the concentration of poloxamer F-127 in the ethanol solution is 4.7 g/100 mL, and the solvent is ethanol; hydrochloric acid and glacial acetic acid are added to the active liquid, and the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:2:4, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; after the addition is completed, the active liquid is stirred and the mixture is stirred for 3 hours. The active solution was stirred for 20 minutes, and then tetraethyl orthosilicate and zirconium n-butoxide were added to the active solution under stirring, wherein the added mass ratio of the tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 was tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 2.4 g: 4 g: 50 mL; after the addition was completed, the active solution was stirred for 2 hours, and after stirring, the active solution was kept at a constant temperature of 70±3° C. in a water bath for 20 hours, and then the solid-liquid separation was carried out, and the solid phase was calcined at 480° C. for 1 hour to obtain the Si-Zr composite oxide;

(3) The modified powder, Si-Zr composite oxide, α-alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the weight proportion of each component (all powders passing through a 300-mesh sieve) is as follows: 7 parts of modified powder, 7 parts of Si-Zr composite oxide, 23 parts of α-alumina powder, 5 parts of magnesium oxide powder, 14 parts of potassium feldspar and 18 parts of clay; the mixture is wet-milled using a planetary ball mill, and the mass ratio of ball to material to water is ball: material: water = 2:1:1 The ball milling speed is 100r/min, the ball milling time is 8h, the iron is removed after ball milling, the water content is adjusted to 25wt%, and the insulator blank and the sample blank are pressed. The insulator blank and the sample blank are dried at 110°C for 40h, then heated to 450°C at 10°C/min and calcined for 1h, then heated to 1260°C at 5°C/min and sintered for 3h, then cooled to 300°C at 5°C/min, and then air-cooled to room temperature to obtain the high-strength porcelain insulator and test sample described in this comparative example.

Example 5

The tensile strength and breakdown voltage of the test samples prepared by the methods described in the above embodiments and comparative examples were tested, and the results are shown in Table 1.

Table 1

Experimental Group Tensile strength/MPa Breakdown voltage/kV Example 1 256.3 161 Example 2 264.9 166 Example 3 266.2 168 Example 4 260.5 163 Comparative Example 1 229.1 121 Comparative Example 2 187.4 117 Comparative Example 3 208.0 158

As can be seen from Table 1, the porcelain insulator insulator material prepared by the method of the present invention has good mechanical strength and insulation. By adding the modified powder of the present invention, Si-Zr composite oxide and carbon-attached alumina powder to the insulator raw material, the tensile strength and breakdown voltage of the material can be significantly improved. This is mainly because the addition of these components makes the crystal structure of the material more compact, with fewer holes and defects, which is manifested as higher strength and breakdown voltage value on a macro scale.

The technical solution provided by the present invention is introduced in detail above. For those skilled in the art, according to the concept of the embodiments of the present invention, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims (1)

1. A method for preparing a high-strength porcelain insulator, characterized in that it comprises the following steps: (1) Preparation of modified powder: ethanol, deionized water and cerium nitrate are mixed to form a mixed solution, wherein the mass ratio of ethanol, deionized water and cerium nitrate is ethanol: deionized water: cerium nitrate = 20:80:1-2; an ethanol solution of n-butyl titanate is prepared, wherein the mass percentage of n-butyl titanate in the ethanol solution of n-butyl titanate is 16%-20%; the ethanol solution of n-butyl titanate is stirred, and the mixed solution is added to the solution during the stirring process, and glacial acetic acid is added to the solution under stirring after the addition of the mixed solution is completed, and the volume ratio of the mixed solution and glacial acetic acid to the ethanol solution of n-butyl titanate is n-butyl titanate ethanol solution: mixed solution: glacial acetic acid = 2:1-2:0.4-0.6; after the addition is completed, the solution is stirred for more than 20 minutes, and after the stirring is completed, it is aged at room temperature for more than 70 hours, and then the pressure is reduced. Concentration, solid-liquid separation, calcining the solid phase at 500-530°C for 2-3h to obtain a powder solid phase A; adding barium hydroxide to deionized water in a reactor, keeping the water bath constant at 90±2°C so that the barium hydroxide is completely dissolved to obtain an aqueous solution of barium hydroxide, wherein the concentration of barium hydroxide in the aqueous solution of barium hydroxide is 2-3mmol/L, stirring the aqueous solution of barium hydroxide at a constant temperature of 90±2°C, adding the powder solid phase to the solution during stirring, and adding the powder solid phase A to the aqueous solution of barium hydroxide in a solid-liquid mass ratio of powder solid phase A to the aqueous solution of barium hydroxide is powder solid phase A: aqueous solution of barium hydroxide = 1:8; after the addition is completed, the reactor is closed, heated to 140-160°C and kept warm for more than 10h, then air-cooled to room temperature, the reactor is opened, the solid-liquid separation is performed, the solid phase is washed with deionized water, and dried to obtain the modified powder; (2) Preparation of Si-Zr composite oxide: an ethanol solution of poloxamer F-127 is prepared as an active liquid, wherein the concentration of poloxamer F-127 in the ethanol solution is 4.5-4.8 g/100 mL, and the solvent is ethanol; hydrochloric acid and glacial acetic acid are added to the active liquid, and the volume ratio of hydrochloric acid and glacial acetic acid added to the active liquid is active liquid: hydrochloric acid: glacial acetic acid = 50:1-2:3-5, wherein the mass percentage of the solute in the hydrochloric acid is 30%, and the solvent is water; after the addition is completed, the active liquid is stirred for 20-30 min. in, then adding tetraethyl orthosilicate and zirconium n-butoxide to the active liquid under stirring, the volume ratio of the added mass of the tetraethyl orthosilicate and zirconium n-butoxide to the ethanol solution of poloxamer F-127 is tetraethyl orthosilicate: zirconium n-butoxide: ethanol solution of poloxamer F-127 = 1.8-2.8 g: 3-5 g: 50 mL; stirring for more than 2 hours after the addition is completed, and after stirring, the active liquid is kept at a constant temperature of 70±3° C. in a water bath for more than 20 hours, and then solid-liquid separation is performed, and the solid phase is calcined at 450-480° C. for 1-2 hours to obtain the Si-Zr composite oxide; (3) preparing an aqueous solution of glucose, wherein the concentration of glucose in the aqueous solution is 15 to 20 g/100 mL, and the solvent is water; soaking α-alumina in the aqueous solution of glucose to obtain a suspension, wherein the solid-liquid mass ratio of the suspension obtained by soaking α-alumina in the aqueous solution of glucose is solid/liquid=1:5; placing the suspension in a vacuum box, maintaining the pressure at 0.01 standard atmospheric pressure for more than 30 minutes, and then maintaining the pressure in a water bath at 80±5°C for more than 30 minutes, then separating the solid and the liquid, and drying the solid phase at 120°C for more than 2 hours to obtain an alumina powder with glucose adhered to the surface, and heating the alumina powder with glucose adhered to the surface to 800 to 820°C in a nitrogen atmosphere for carbonization for more than 5 hours to obtain a carbon-attached alumina powder; (4) The modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture, wherein the modified powder, Si-Zr composite oxide, carbon-attached alumina powder, magnesium oxide powder, potassium feldspar and clay are uniformly mixed to form a mixture in the following proportions by weight: 3-8 parts of modified powder, 6-8 parts of Si-Zr composite oxide, 20-25 parts of carbon-attached alumina powder, 4-6 parts of magnesium oxide powder, 12-16 parts of potassium feldspar, and 10-25 parts of potassium feldspar. 14 to 20 parts; wet ball milling the mixture, removing iron after ball milling, adjusting the water content to 23 to 25wt%, pressing into a blank, drying the blank at 100 to 110°C for more than 40h, then heating to 450 to 500°C at 10°C/min and calcining for 1 to 2h, then heating to 1250 to 1280°C at 5°C/min and sintering for 3 to 4h, then cooling to 300°C at 5°C/min, and then air cooling to room temperature to obtain the high-strength porcelain insulator.