CN111056841A

CN111056841A - Method for manufacturing rare earth reinforced graphite plate

Info

Publication number: CN111056841A
Application number: CN201911373923.0A
Authority: CN
Inventors: 欧阳建国; 张战
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-04-24

Abstract

The invention discloses a method for manufacturing a rare earth reinforced graphite plate, which comprises the following steps: 1) mixing the following raw materials in parts by weight: 40-100 parts of rare earth powder, 200-400 parts of medium-temperature asphalt powder, 300-400 parts of forming agent, 10-100 parts of high-purity ferroalloy powder and 2000-3000 parts of petroleum coke powder: 2) pressing the mixed raw materials into blocks; 3) degumming the blocky object at the temperature of 100-: raising the pressure and raising the temperature while raising the pressure, stopping heating and raising the pressure after the pressure is raised to 40-80Mpa and the temperature reaches 800-; 4) the carbon block is heated to 1600-: 8-20 percent, and obvious economic benefit.

Description

Method for manufacturing rare earth reinforced graphite plate

Technical Field

The invention relates to a method for manufacturing a graphite plate, in particular to a method for manufacturing a rare earth reinforced graphite plate.

Background

The graphite has the following special properties of 1) high temperature resistance due to the special structure, wherein the melting point of the graphite is 3850 +/-50 ℃, the boiling point of the graphite is 4250 ℃, and even if the graphite is burnt by an ultrahigh-temperature electric arc, the weight loss is very small, and the thermal expansion coefficient is also very small. The strength of the graphite can be enhanced along with the increase of the temperature, and the strength of the graphite is doubled at 2000 ℃. 2) The electric conductivity and the thermal conductivity of the graphite are one hundred times higher than those of common non-metallic ores. The thermal conductivity exceeds that of metal materials such as steel, iron, lead and the like. The thermal conductivity decreases with increasing temperature and even at very high temperatures, graphite forms a thermal insulator. Graphite is electrically conductive because each carbon atom in graphite forms only 3 covalent bonds with other carbon atoms and each carbon atom still retains 1 free electron to transport charge. 3) The lubricating property of the graphite depends on the size of graphite flakes, and the larger the flakes are, the smaller the friction coefficient is, and the better the lubricating property is. 4) The graphite has good chemical stability at normal temperature, and can resist acid, alkali and corrosion of organic solvents. 5) Plasticity, the toughness of the graphite is good, and the graphite can be ground into thin sheets. 6) Thermal shock resistance, namely that the graphite can withstand violent temperature change without damage when used at normal temperature, and the volume change of the graphite is not large and cracks are not generated when the temperature changes suddenly. Graphite is used in a wide range of industries and is used in almost every industry.

Currently, artificial graphite is widely used in industry. The following methods can be used for molding. 1. Isostatic pressing of graphite. Namely, three-high graphite, which is called by many people, but is not three-high or isostatic. 2. And molding graphite. 3. Most of the extruded graphite is an electrode material. The graphite can be divided into fine structure graphite, medium coarse graphite (the general granularity is about 0.8 mm) and electrode graphite (2-4mm) according to the particle size of the graphite. The graphite with high purity, high strength, high density and high modulus is called special graphite, has special physical and chemical characteristics, and is widely applied to the industries of aluminum industry, steel industry, glass manufacturing, environmental protection, chemical industry, aerospace, metal manufacturing, nuclear power electronic science, sliding contact machinery, rubber industry, structural casting molds, electric heating elements, single crystal furnace heaters, crucibles for smelting precious metals, electric spark processing, sintering molds, metal coating and the like.

Artificial graphite production is generally produced by mixing coke and adherent pitch in a baking furnace at a temperature of 1000 to 1300 ℃ and then coking the mixture, and then graphitizing the carbon in an electric furnace at a temperature of 2500 to 3000 ℃ to process an amorphous carbon body into the structure of crystalline graphite, which is called graphitization. Before graphitizing the carbon material, in order to improve the electrical and mechanical properties, the carbon material is soaked with asphalt and baked again. Generally, the conventional graphite production needs multiple times of soaking and roasting (three times of soaking and four times of roasting), the production period usually needs about 6 months, and the asphalt is used in an amount of more than 35%.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for manufacturing a rare earth reinforced graphite plate with short production period and low production cost.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for manufacturing a rare earth reinforced graphite plate comprises the following steps:

1) mixing the following raw materials in parts by weight: 40-100 parts of rare earth powder, 200-400 parts of medium-temperature asphalt powder, 300-400 parts of forming agent, 10-100 parts of high-purity ferroalloy powder and 2000-3000 parts of petroleum coke powder:

2) pressing the mixed raw materials into blocks;

3) degumming the blocky object at the temperature of 100-: raising the pressure and raising the temperature while raising the pressure, stopping heating and raising the pressure after the pressure is raised to 40-80Mpa and the temperature reaches 800-;

4) the carbon block is heated to 1600-2800 ℃ for tempering treatment to obtain the rare earth reinforced graphite plate.

The particle size of the rare earth powder is 1-3 microns, the purity of the medium-temperature asphalt powder is 98.0%, and the particle size of the high-purity ferroalloy powder is 10-50 microns, and the purity is 99.0%.

The rare earth is cerium oxide.

The medium-temperature asphalt powder is asphalt powder with the softening temperature of 60 ℃.

The forming agent is sticky rice adhesive, and the sticky rice adhesive is prepared by the following method: adding 9-10 kg of water into each kg of glutinous rice, adding the proportioned glutinous rice with water and putting the glutinous rice into a container provided with a rotary blade, stopping heating when the glutinous rice is heated to 100 ℃, and simultaneously starting the rotary blade to operate for 1 minute at 3000 revolutions per minute; starting the heating system again to heat to 100 ℃, stopping heating and simultaneously starting the rotary blade to operate for 1 minute at 3000 revolutions per minute; the above steps are repeated for 10-12 times to obtain the non-particle/high-viscosity glutinous rice adhesive.

Compared with the prior art, the invention has the advantages that the production cycle is shortened to a few days from about 6 months in the prior art by the high-temperature and high-pressure sintering technology and the new bonding auxiliary agent (sticky rice adhesive), the environmental pollution and the time cost are greatly reduced, and the asphalt amount is reduced to: 8-20 percent, and obvious economic benefit. The graphite plate prepared by the method has the volume density of more than 1.88g/cm2, the highest volume density of 1.92g/cm3, the bending strength of more than 60MPa, the highest volume density of 70MPa, the compression strength of more than 90MPa, the highest volume density of 100MPa, the hardness of Shore80-85 and the thermal expansion coefficient of 4.47EX10^-6/° c, the thermal conductivity is 60W/m ℃.

Drawings

FIG. 1 is a graph of a synthetic process according to an embodiment of the present invention.

In the figure, the abscissa is a time axis, the ordinate is qualitative representation of pressure and power, the pressure line means the pressure increasing, pressure maintaining and pressure releasing processes which change along with time, and the pressure line P represents the pressure maintaining for a period of time; the power lines are the whole process of temperature rise, heat preservation and temperature drop which change along with time, wherein the power lines A, B respectively represent a period of constant power.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Example 1, 40 g of 1-3 μm cerium oxide powder was weighed; weighing 200 g of medium-temperature asphalt powder with the softening temperature of 60 ℃ (the purity is 98.0%); weighing 300 g of glutinous rice adhesive; weighing 10 g of 10-50 micron high-purity ferroalloy powder (99.0%); weighing 2000 g of petroleum coke powder; fully mixing the five materials, pressing the materials into blocks in a mould by using a four-column press, degumming at 100 ℃, putting the blocks into 3000-ton composite pyrophyllite specially prepared for a double-sided pressure full-automatic hot press according to a 3000-ton double-sided pressure full-automatic hot press hot-pressing sintering process method shown in the figure 1, raising the pressure while raising the temperature, stopping heating and raising the pressure after the pressure is raised to 40-80Mpa and the temperature reaches 800-; according to different sizes and times of workpieces, the synthesis time is 40-480 minutes, the carbon test block is taken out after pressure relief, the carbon test block is placed in an electric furnace and heated to 1600 ℃ for tempering treatment, the test block density is 1.88g/cm2, the bending strength is not lower than 60MPA, and the compressive strength is not lower than 90 Mpa; hardness greater than shore80, and thermal expansion coefficient of 4.34EX10^-6/° c, the thermal conductivity was 61W/m ℃.

Example 2, 80 g of 1-3 micron cerium oxide powder was weighed; weighing 300 g of medium-temperature asphalt powder with the softening temperature of 60 ℃ (purity is 98.0%); weighing 400 g of glutinous rice adhesive; weighing 100 g of 10-50 micron high-purity silicon carbide powder (99.0%); weighing 2000 g of petroleum coke powder; fully mixing the five materials, pressing the materials into blocks in a die by using a four-column press, degumming at 800 ℃, putting the blocks into 3000-ton composite pyrophyllite specially made for a double-sided pressure full-automatic hot press according to a 3000-ton double-sided pressure full-automatic hot press hot-pressing sintering process method shown in the figure 1, raising the pressure while raising the temperature, stopping heating and raising the pressure after the pressure is raised to 40-80Mpa and the temperature reaches 800-1200 ℃, preserving the temperature for 30 minutes, reducing the temperature for 10 minutes and then releasing the pressure; according to different sizes and times of workpieces, the synthesis time is 40-480 minutes, the carbon test block is taken out after pressure relief, the carbon test block is placed in an electric furnace and heated to 2800 ℃ for tempering treatment, the test block density is 1.92g/cm2, the bending strength is not lower than 68MPA, and the compressive strength is not lower than 100 Mpa; hardness greater than shore85, and thermal expansion coefficient of 5.60EX10^-6/° c, the thermal conductivity is 60W/m ℃.

Example 3, title 1001-3 micron cerium oxide powder; weighing 400 g of medium-temperature asphalt powder with the softening temperature of 60 ℃ (purity is 98.0%); weighing 400 g of glutinous rice adhesive; weighing 100 g of 10-50 micron high-purity ferroalloy powder (99.0%); weighing 3000 g of petroleum coke powder; fully mixing the five materials, pressing the materials into blocks in a die by using a four-column press, degumming at 400 ℃, putting the blocks into 3000-ton composite pyrophyllite specially made for a double-sided pressure full-automatic hot press according to a 3000-ton double-sided pressure full-automatic hot press hot-pressing sintering process method shown in the figure 1, raising the pressure while raising the temperature, stopping heating and raising the pressure after the pressure is raised to 40-80Mpa and the temperature reaches 800-1200 ℃, preserving the temperature for 30 minutes, reducing the temperature for 10 minutes and then releasing the pressure; according to different sizes and times of workpieces, the synthesis time is 40-480 minutes, the carbon test block is taken out after pressure relief, the carbon test block is placed in an electric furnace and heated to 2200 ℃ for tempering treatment, the test block density is 1.96g/cm2, the bending strength is not lower than 70MPA, and the compressive strength is not lower than 100 Mpa; hardness greater than shore82, and thermal expansion coefficient of 4.70EX10^-6/° c, the thermal conductivity was 64W/m ℃.

The above examples are only incomplete examples of the present invention, and cerium oxide powder may be substituted with various rare earth powders.

The glutinous rice adhesive used as the forming agent has the following formula and preparation method: adding 9-10 kg of water into each kg of glutinous rice, adding the proportioned glutinous rice with water and putting the glutinous rice into a container provided with a rotary blade, stopping heating when the glutinous rice is heated to 100 ℃, and simultaneously starting the rotary blade to operate for 1 minute at 3000 revolutions per minute; starting the heating system again to heat to 100 ℃, stopping heating and simultaneously starting the rotary blade to operate for 1 minute at 3000 revolutions per minute; the above steps are repeated for 10-12 times to obtain the non-particle/high-viscosity glutinous rice adhesive. .

Claims

1. A method for manufacturing a rare earth reinforced graphite plate is characterized by comprising the following steps:

2) pressing the mixed raw materials into blocks;

2. The method of manufacturing a rare earth-reinforced graphite sheet according to claim 1, wherein the particle size of the rare earth powder is 1 to 3 μm, the purity of the medium-temperature asphalt powder is 98.0%, and the particle size of the high-purity iron alloy powder is 10 to 50 μm and the purity is 99.0%.

3. The method for producing a rare earth-reinforced graphite sheet according to claim 1 or 2, wherein the rare earth is cerium oxide.

4. The method for manufacturing a rare earth-reinforced graphite sheet according to claim 1 or 2, wherein the medium-temperature asphalt powder is asphalt powder having a softening temperature of 60 ℃.

5. The method for manufacturing a rare earth-reinforced graphite sheet according to claim 1, wherein the molding agent is a glutinous rice binder, and the glutinous rice binder is prepared by the following method: adding 9-10 kg of water into each kg of glutinous rice, adding the proportioned glutinous rice with water and putting the glutinous rice into a container provided with a rotary blade, stopping heating when the glutinous rice is heated to 100 ℃, and simultaneously starting the rotary blade to operate for 1 minute at 3000 revolutions per minute; starting the heating system again to heat to 100 ℃, stopping heating and simultaneously starting the rotary blade to operate for 1 minute at 3000 revolutions per minute; the above steps are repeated for 10-12 times to obtain the non-particle/high-viscosity glutinous rice adhesive.