CN115108833B

CN115108833B - Continuous casting graphite material and preparation method thereof

Info

Publication number: CN115108833B
Application number: CN202210926461.6A
Authority: CN
Inventors: 朱约辉; 廖仕明
Original assignee: Hubei Southeast Jiate Carbon New Material Co ltd
Current assignee: Hubei Southeast Jiate Carbon New Material Co ltd
Priority date: 2022-08-03
Filing date: 2022-08-03
Publication date: 2023-08-18
Anticipated expiration: 2042-08-03
Also published as: CN115108833A

Abstract

The invention discloses continuous casting graphite and a preparation method thereof, and belongs to the technical field of material science. The continuous casting graphite material prepared by the method has high wear resistance, good sealing performance, good heat conduction and good physical, mechanical and chemical properties in the use process.

Description

Continuous casting graphite material and preparation method thereof

Technical Field

The invention relates to a graphite material and a preparation method thereof, in particular to continuous casting graphite and a preparation method thereof, and belongs to the field of special graphite.

Background

Continuous casting graphite (graphite for continuous casting mold) refers to a graphite product for use in a continuous casting mold. The metal continuous casting technique is a new technique of directly forming a molten metal into a material through a continuous casting mold. Because it is directly formed without rolling, the secondary heating of metal is avoided, so that a large amount of energy sources can be saved.

The continuous casting graphite is prepared from carbonaceous raw materials (petroleum coke, asphalt coke, coal asphalt and the like) through a series of production process steps, wherein the compression molding process can adopt cold molding or cold isostatic pressing process respectively. The adoption of the advanced high-tonnage cold isostatic pressing process can ensure the production of continuous casting graphite with uniform, compact and high strength. The surface coating technology treatment is added, so that the service life of the graphite crystallizer can be prolonged, the quality of the surface of the continuous casting metal is improved, and the continuous casting process speed is improved.

In recent years, copper pipe forming continuous casting graphite is mainly suitable for drawing copper forming, at present, more than 100% of domestic continuous casting graphite still adopts imported materials, at present, no product for replacing imported materials exists in China, but compared with foreign similar products, the problems of abrasion resistance, internal structure and stability of friction coefficient of the continuous casting graphite are solved, and the problems of stability of the internal structure, abrasion resistance under the condition of drawing copper operation and the like are also certain. At present, the main material combination of petroleum coke and asphalt binder is commonly adopted.

At present, continuous casting graphite is mainly researched on the basis of mould pressing, raw materials are limited to asphalt coke series, and the preparation method generally adopts the technological processes of kneading, grinding, mould pressing, roasting, dipping, roasting and graphitizing, and the existing preparation method has the following technical defects: complicated operation process steps, long preparation and production time, high production cost and low production efficiency; and the quality of the prepared product is unstable, and the product performance is poor.

Disclosure of Invention

The primary purpose of the invention is to provide the copper pipe molding continuous casting graphite and the preparation method thereof, aiming at the technical problems existing in the prior continuous casting graphite technology.

In order to achieve the purpose of the invention, the invention provides a preparation method of a continuous casting graphite material, which comprises the following steps:

1) Adding continuous casting graphite raw materials including asphalt coke, petroleum coke, artificial graphite and spray carbon black into a kneading pot with the temperature kept at 90-100 ℃ for first kneading treatment; uniformly mixing to obtain an asphalt coke-petroleum coke-graphite-carbon black mixture; then adding raw materials of sulfur and molybdenum disulfide, heating and raising the temperature, and carrying out second kneading treatment; after uniform mixing, heating to 160-200 ℃, adding modified asphalt under the condition of keeping the temperature in a kneading pot to 160-200 ℃, and carrying out third kneading treatment to obtain a kneading mixture;

2) Crushing the kneaded mixture, and sieving to obtain mixed crushed materials;

3) Grinding the mixed crushed materials, and sieving to obtain mixed micro powder;

4) Placing the mixed micro powder material into a die of a press, and performing pressing treatment to prepare a pressed blank;

5) Placing the pressed blank in an isostatic pressing machine, and performing forming treatment to obtain a formed blank;

6) Placing the molded blank into a roasting kiln, and performing first sintering treatment to prepare a first sintered blank;

7) Placing the first sintered blank into an impregnating tank for vacuumizing treatment until the vacuum degree in the impregnating tank is lower than 5torr (gauge pressure, preferably 3-5 torr), adding molten medium-temperature asphalt into the impregnating tank, and then performing pressurization-impregnation treatment to obtain an impregnated blank;

8) Placing the impregnated blank in a roasting kiln, and performing second sintering treatment to obtain a second sintered blank;

9) And (3) placing the second sintered blank in a graphitizing furnace, and performing graphitizing treatment to obtain the continuous casting graphite.

Wherein, the raw materials of the continuous casting graphite comprise asphalt coke, petroleum coke, artificial graphite, spray carbon black, sulfur, molybdenum disulfide, modified asphalt and medium-temperature asphalt, and the raw materials comprise the following components in parts by weight:

artificial graphite: the granularity is-300 meshes, the carbon content is more than or equal to 99 percent, and the ash content is less than or equal to 1 percent; the artificial graphite has the characteristics of light weight, electric conduction, heat conduction, good lubricating property, excellent machining property and the like.

Modified asphalt: the yield of the tar is 54-56% of the tar distillation raffinate, and the tar distillation raffinate consists of more than three-ring aromatic compounds, oxygen-containing, nitrogen-containing and sulfur-containing heterocyclic compounds and a small amount of high molecular carbon substances. Modified asphalt: softening point: toluene insoluble material at 105-112 ℃): 25-28%, quinoline insoluble: 6-12%; coking means: more than or equal to 58 percent, volatile matters: 50-55%. Acting as a binder in the material.

Asphalt coke: the granularity is-300 meshes, the moisture is less than or equal to 1 percent, the ash content is less than or equal to 1 percent, and the true density is more than or equal to 1.98g/cm ³ . Low sulfur cooked coke cake is adopted. The asphalt coke has the characteristics of wear resistance, stable friction coefficient and the like, so that the wear resistance of the material and the strength of the whole material can be improved by adding the asphalt coke, and the copper water can not react with the asphalt coke in the drawing and forming process.

Petroleum coke: the granularity is-300 meshes, the moisture is less than or equal to 1 percent, and the ash content is less than or equal to 1 percent. Low sulfur cooked coke cake is adopted. The petroleum coke has the characteristics of heat resistance, wear resistance, stable friction coefficient, low loss and the like, so that the addition of the petroleum coke can improve the heat resistance and the wear resistance of the material, improve the friction coefficient of the material and reduce the loss of the material.

Spray carbon black (i.e., powdered spray carbon black): the mesh number is-300 mesh, and the main purpose is to increase the wear resistance of the product and fill the pores inside the product so as to prevent copper water from diffusing into graphite during the use process, thereby causing cracking of continuous casting graphite.

Sulfur: the mesh number is-200 mesh, and sulfur is mainly adopted to improve the carbon residue rate of the product and reduce the ash content.

Molybdenum disulfide: the mesh number is minus 2000 mesh, the lubricating performance is good, the wear resistance is good, the friction increasing effect can be achieved at high temperature, and the wear resistance of the continuous casting graphite material is improved by adding molybdenum disulfide; and the molybdenum disulfide has high melting point, and is suitable for mechanical working states of high temperature, high pressure, high rotating speed and high load.

In particular, the first kneading treatment temperature in step 1) is 90-100 ℃; the second kneading treatment temperature is 160-180 ℃; the third kneading treatment temperature is 160-200 ℃.

In particular, the first kneading treatment temperature in step 1) is preferably 95 ℃; the first kneading treatment is carried out for at least 30min, preferably 30-60min; the second kneading treatment temperature is preferably 170 ℃; a second kneading treatment for 30-50min, preferably 40min; the third kneading treatment temperature is preferably 190 ℃; the third kneading treatment is carried out for 120-150min, preferably 130min.

And stopping heating after the third kneading treatment is performed for 120-150min, and pouring the mixture into a material box to continuously cool to room temperature after the temperature in the kneading pot is reduced to below 100 ℃ to obtain the kneaded mixture.

In particular, the kneading pot is heated until the temperature in the kneading pot reaches and is maintained at 90-100 ℃ before adding pitch coke, petroleum coke, artificial graphite and spray carbon black into the kneading pot.

In particular, the modified asphalt is melted modified asphalt, namely, the modified asphalt is placed in an asphalt melting tank and heated to 160-200 ℃ to be melted into liquid; then adding the mixture into a kneading pot, and carrying out third kneading treatment.

In particular, before adding raw materials of pitch coke, petroleum coke, artificial graphite and spray carbon black in the step 1), heating the kneading pot, and adding the raw materials again when the temperature of the kneading pot reaches and is kept to be 90-100 ℃ (preferably 95 ℃), so as to carry out first kneading treatment.

Wherein the granularity of the mixed crushed material in the step 2) is less than or equal to 40 meshes.

In particular, in step 2), the kneaded mixture is placed in a crusher to perform the crushing treatment; the sieving treatment refers to that after crushing, the crushed materials pass through a sieve with 30-50 meshes, and the materials under the sieve, namely the materials passing through the sieve, are mixed crushed materials.

In particular, the mixture is sieved by a 40-mesh sieve to obtain mixed crushed materials with the granularity less than or equal to 40 meshes.

Wherein, in the step 3), the mixed crushed materials are put into a pulverizer for the pulverizing treatment.

In particular, the particle size of the mixed micropowders is 15-18 mu m.

Wherein the pressure of the pressing treatment in step 4) is 2-6MPa, preferably 2-5MPa; the pressing treatment time is 25-40min.

In particular, the method further comprises the step of placing the material micropowder into a V-shaped mixing pot for mixing for 2-4 hours, preferably 3 hours, before the compacting treatment.

In particular, the press is a 1250t model press.

Wherein the molding treatment time in step 5) is 0.5 to 1h, preferably 0.8h; the relative pressure of the molding treatment is 180-200MPa, preferably 190-200MPa.

In particular, the molding process is carried out by placing the molded blank in an isostatic press, wherein the molding pressure is 180-200MPa, preferably 190-200MPa; the molding treatment time is 0.5 to 1h, preferably 0.8h.

Wherein the first sintering treatment temperature in step 6) is 900-1000 ℃, preferably 900-950 ℃; the first sintering treatment time is 25 to 30 days, preferably 25 days.

Wherein the relative pressure of the pressure-impregnation treatment in step 7) is 2-3.5MP, preferably 2-3.0MPa; the pressure-impregnation treatment time is 8 to 10 hours, preferably 9 hours.

In particular, the pressure-impregnation treatment temperature is 180-190 ℃.

In particular, the molten medium temperature asphalt is prepared according to the following method: and (3) placing the medium-temperature asphalt into an asphalt melting tank, heating to 180-190 ℃, and adding the medium-temperature asphalt for at least 6 hours to melt the medium-temperature asphalt into liquid to obtain the asphalt.

In particular, the method further comprises the step of airing the impregnated blank at room temperature, wherein the airing time is at least 24 hours.

Wherein the temperature of the second sintering treatment in step 8) is 900-1000 ℃, preferably 900-950 ℃; the second sintering time is 35 to 45 days, preferably 40 days.

In particular, the graphitization treatment in step 9) is carried out at a temperature of 2700 to 2800 ℃; the graphitization treatment time is 600-650h, preferably 600h.

In another aspect, the invention provides a continuous casting graphite material prepared by any of the methods described above.

Compared with the prior art, the continuous casting graphite has the following advantages:

1. in the preparation process of the continuous casting graphite, the operation process condition is stable, the controllability is high, the equipment is stable, the mixing uniformity of raw materials is high, and the product quality is high;

2. the continuous casting graphite product prepared by the method has more uniform internal structure, and the isostatic pressing treatment ensures that the product is pressed and molded simultaneously in different directions around, thereby improving the compactness of the internal structure of the product and the density uniformity of the product;

3. the method adopts a car bottom type roasting process instead of a ring type furnace roasting mode, the temperature is uniform in the roasting process, the temperature difference in the furnace is +/-10 ℃, circulating air is carried out, the temperature is uniform in the product roasting process, and the product defect caused by stress of the product due to the temperature difference is avoided;

4. the continuous casting graphite prepared by the method has good wear resistance and sealing performance; good heat conduction and good physical, mechanical and chemical properties.

5. The method of the invention aims at improving the existing process, mainly reducing the process flow, increasing the isostatic pressing process, mainly increasing the combination of the density and the granularity of the product, enabling one-time roasting to meet the process parameter requirement, achieving the process requirement after one-time soaking, shortening the time, reducing the cost and making the subsequent process improvement as the basis.

Drawings

FIG. 1 is a process flow chart of the preparation method of continuous casting graphite.

Detailed Description

The invention will be further described with reference to specific embodiments, and advantages and features of the invention will become apparent from the description. These examples are merely exemplary and do not limit the scope of the invention in any way. It will be understood by those skilled in the art that various changes and substitutions of details and forms of the technical solution of the present invention may be made without departing from the spirit and scope of the present invention, but these changes and substitutions fall within the scope of the present invention.

Example 1

1. The following materials (kg) are prepared according to the weight ratio:

wherein, the softening point of the modified asphalt: 105-112 ℃; toluene insolubles: 25-28%; quinoline insolubles: 6-12%; coking means: more than or equal to 58 percent, volatile matters: 50-55%;

the granularity of the asphalt coke is-300 meshes, the moisture is less than or equal to 1%, the ash content is less than or equal to 1%, and the true density is more than or equal to 1.98g/cm ³ ；

The granularity of the petroleum coke is-300 meshes, the moisture is less than or equal to 1%, and the ash content is less than or equal to 1%;

spraying carbon black: the mesh number is-300 mesh; sulfur: the mesh number is-200 mesh;

molybdenum disulfide: the mesh number is-2000 mesh

2. Starting a kneading pot, heating to raise the temperature, keeping the temperature in the kneading pot at 95 ℃ (usually 90-100 ℃), adding raw materials of pitch coke, petroleum coke, artificial graphite and spray carbon black into the kneading pot, carrying out first kneading treatment, and mixing for 30min (usually at least 30min, preferably 30-60 min) to prepare a pitch coke-petroleum coke-graphite-carbon black mixture;

in the embodiment, the temperature of adding raw materials of asphalt coke, petroleum coke, artificial graphite and spray carbon black is 95 ℃ for example, and other temperatures of 90-100 ℃ are applicable; the first kneading treatment temperature is exemplified by 95 ℃, and other temperatures of 90-100 ℃ are applicable; the mixing time is exemplified by 30min, and other times are suitable for more than 30min.

3. Adding sulfur and molybdenum disulfide into the asphalt coke-petroleum coke-graphite-carbon black mixture in the mixing and kneading pot, continuously heating until the temperature in the mixing and kneading pot is increased to 170 ℃ (usually 160-180 ℃), and carrying out second mixing and kneading treatment under the condition that the temperature is kept at 170 ℃ (usually 160-180 ℃), wherein the second mixing and kneading treatment time is 40min (usually 30-50 min);

in the embodiment, the temperature of adding raw materials of sulfur and molybdenum disulfide is taken as an example at 170 ℃, and other temperatures of 160-180 ℃ are applicable; the second kneading treatment temperature is 170 ℃ for example, and other temperatures of 160-180 ℃ are applicable; the second kneading time is exemplified by 40min, and other times of 30-50min are suitable.

According to the invention, raw materials of the continuous casting graphite are added separately, raw materials are mixed uniformly, and raw materials with high consumption are added and mixed first, and raw materials with low consumption are added after raw materials with high consumption are mixed uniformly, so that uneven material mixing can be prevented; the raw material sulfur is added in the subsequent high-temperature stage, so that sulfur bonds are formed in the carbon material, the wetting and coating of the binder on the carbon material are assisted, the binder exists in the form of functional groups such as carbon groups, and carbon formation is possibly assisted to a certain extent; after the sulfur is added, the temperature is raised again, so that the sulfur content in the sulfur volatilizes, the combination with raw materials is promoted, and the carbon formation is facilitated; in addition, the temperature is raised again, thereby being beneficial to the emission of volatile matters and meeting the process requirements.

4. Heating to 190 ℃ after the second kneading for 40min (usually 160-200 ℃), adding melted modified asphalt into a kneading pot under the condition of keeping the temperature at 190 ℃, carrying out third kneading treatment, stopping heating after 130min (usually 120-150 min) of the third kneading treatment, pouring the kneaded mixture into a material box after the temperature in the kneading pot is reduced to 100 ℃ (usually less than 100 ℃), and cooling to room temperature to obtain a kneaded mixture, wherein the modified asphalt is put into an asphalt melting pot, and the asphalt is melted into liquid after the temperature is heated to 180-190 ℃ for about 6 hours;

in this embodiment, the temperature of the modified asphalt added with the raw material is 190 ℃ as an example, and other temperatures of 160-200 ℃ are applicable; the third kneading treatment temperature is 190 ℃ for example, and other temperatures of 160-200 ℃ are applicable; the third kneading time is 130min for example, and other times 120-150min are suitable.

The modified asphalt is subjected to melting treatment to remove impurities in the modified asphalt, so that the prepared product is prevented from cracking due to the fact that the impurities in the modified asphalt are mixed into raw materials; and the modified asphalt is favorable for mixing with raw materials after being melted, and is uniformly mixed.

5. Putting the kneaded mixture cooled to room temperature in the material box into a crusher for crushing treatment, and sieving the kneaded mixture with a 40-mesh sieve (usually a 30-50-mesh sieve) to obtain mixed crushed materials;

in the invention, a 40-mesh sieve is taken as an example of the sieving after crushing treatment, and other 30-50-mesh sieves are applicable.

The sieving is mainly to sieve the granules and then crush the granules again, because coarse granules are not good to directly enter the superfine pulverizer, and the granule size after sieving by a 40-mesh sieve is suitable for the treatment process of the next superfine pulverizer.

6. Placing the mixed crushed materials into an ultrafine grinding machine, grinding, and sieving to obtain mixed micro powder, wherein the particle size of the mixed micro powder is 15-18 mu m;

7. placing the mixed micro powder into a V-shaped mixing pot for mixing for 3 hours (usually 2-4 hours), and then filling the mixed micro powder into a special material bag;

before the mixed micro powder is pressed, the mixing treatment time is 3 hours as an example, and other mixing time is 2-4 hours.

8. Placing the mixed micro powder into a die of a press (model 1250 t) for pressing treatment to prepare a pressing blank, wherein the absolute pressure of the pressing treatment is 4MPa (usually 2-6 MPa); the pressing treatment time is 30min (usually 25-40 min);

9. placing the pressed blank in an isostatic pressing machine, and performing forming treatment to obtain a formed blank; wherein the absolute pressure of the molding treatment is 190MPa (typically 180-200 MPa); the molding treatment time is 1h (usually 0.5-1 h);

the absolute pressure of the pressing treatment in the invention is taken as an example of 4MPa, and other pressures of 2-6MPa are applicable; the pressing treatment time is exemplified by 30min, and other pressing times of 25-40min are applicable. The absolute pressure of the molding treatment is 190MPa for example, and other pressures of 180-200MPa are applicable; the molding treatment time is exemplified by 1 hour, and other times of 0.5 to 1 hour are applicable.

10. Placing the molded blank in a roasting kiln, and performing a first sintering treatment to prepare a first sintered blank, wherein the temperature of the first sintering treatment is 950 ℃ (typically 900-1000 ℃); the first sintering treatment time is 25 days (typically 25-30 days);

in the embodiment of the invention, the first sintering treatment temperature is 950 ℃ for example, and other temperatures of 900-1000 ℃ are applicable; the sintering time is exemplified by 25 days, and other sintering times such as 25-30 days are suitable.

In the first sintering process, volatile matters generated by roasting are discharged, so that the structure of graphite is changed in the high-temperature process, and sulfur and other volatile matters of asphalt after roasting are combined with other materials to meet the technological requirements.

11. Placing the first sintered blank into an impregnating tank, vacuumizing the impregnating tank until the vacuum degree in the impregnating tank reaches 4torr (gauge pressure, usually 3-5 torr), adding medium-temperature asphalt liquid with the temperature kept at 185 ℃ (usually 180-190 ℃) after melting into the impregnating tank, and stopping vacuumizing after the medium-temperature asphalt liquid is added; the impregnation tank is then pressurized until the relative pressure in the impregnation tube reaches and remains 3MPa (typically 2-3.5 MPa), the first sintered compact in the impregnation tank is subjected to a pressure-impregnation treatment at 185 ℃ (typically 180-190 ℃ and for a period of 9 hours (typically 8-10 hours) to obtain an impregnated compact, and the molten medium-temperature bitumen liquid is obtained by placing medium-temperature bitumen into a bitumen melting tank and heating to 180-190 ℃ until the bitumen melts into a liquid, typically about 6 hours.

In the embodiment of the invention, the vacuum degree of the vacuumizing treatment in the impregnating tank is taken as an example of the gauge pressure of 4torr, and other vacuum degrees of 3-5torr are applicable; the relative pressure of the pressurizing-soaking treatment is exemplified by 3MPa, and other relative pressures such as 2-3.5MPa are applicable; the pressurizing-soaking treatment time is exemplified by 9 hours, and other soaking time such as 8-10 hours are applicable; the pressure impregnation treatment temperature is 185 ℃ for example, and other temperatures 180-190 ℃ are applicable.

The invention carries out dipping treatment, mainly increases the density and index of flexural strength, compressive strength and hardness of the product so as to reach the required index standard; the vacuumization treatment is mainly to extract oxygen in the product, so that the impregnated asphalt liquid is easy to enter the pores of the product structure in the pressurizing process, and fills the pores to achieve the weight gain rate required by the process.

12. Taking out the impregnated blank, airing at room temperature for 24 hours (airing for at least 24 hours, usually 24-36 hours), placing the impregnated blank in a roasting kiln, and carrying out second sintering treatment to obtain a second sintered blank, wherein the second sintering treatment temperature is 950 ℃ (usually 900-1000 ℃); the second sintering treatment time is 40 days (typically 35-45 days);

in the embodiment of the invention, the second sintering treatment temperature is 950 ℃ for example, and other temperatures of 900-1000 ℃ are applicable; the second sintering time is exemplified by 40 days, and other sintering times such as 35-45 days are applicable.

The second sintering process removes ash from the medium temperature pitch used in the impregnation process, and the pitch combines with molecules in the original product.

The invention carries out the first and the second sintering treatments to reduce ash and volatile matters of the raw materials, improve the density and the strength of the raw materials, reduce the shrinkage of products, improve the conductivity (in terms of specific resistance of powder), remove water (< 0.3%) in the raw materials, and reduce oxygen, nitrogen and sulfur heteroatoms so as to be beneficial to graphitization.

13. Placing the second sintered blank in a graphitization furnace for graphitization treatment, and obtaining continuous casting graphite, wherein the graphitization treatment temperature is 2750 ℃ (usually 2700-2800 ℃); the graphitization treatment time is 600 hours (typically 600-650 hours).

The graphitization treatment of the second sintered compact of the present invention is performed using conventional graphitization methods and operation processes in the art, and the graphitization treatment methods and apparatuses in the art for continuous casting graphite preparation are applicable to the present invention. Graphitization is used to increase the electrical and thermal conductivity of the material; improving the thermal and chemical stability of the material, such as oxidation resistance, corrosion resistance, reduced coefficient of thermal expansion, etc.; impurities are removed, and the purity is improved; the ash content is reduced by 70%; the hardness is reduced, and the precision machining of the product is facilitated.

Example 2

The procedure of example 1 was repeated except that the following materials (kg) were prepared in the following weight proportions,

example 3

comparative example

As a control, a continuous casting graphite product of Henan Shangshantianbao carbon manufacturing Co., ltd was used.

Test example Performance detection

The following performance tests were carried out on the continuous casting graphite prepared in example 1 and the continuous casting graphite prepared in comparative example, and the test methods of the respective performances were as follows:

flexural strength: GB/T3074.1-2021; compressive strength: GB/T1431-2019; shore hardness: GB/T39535-2020; bulk density: GB/T24528-2009; resistivity: GB/T24525-2009; coefficient of thermal expansion: GB/T3074.4-2016; thermal conductivity: GB/T8722-2019 method for measuring thermal conductivity coefficient of carbon material; particle size: GB/T21354-2008.

The test results are shown in Table 1.

TABLE 1 results of measurement of continuous cast graphite properties

	Example 1	Comparative example
			Flexural strength (MPa)	50	35
Compressive strength (MPa)	85	60
			Shore hardness	65	45
Bulk Density (g/cm) ³ )	1.85	1.75
			Resistivity (uΩ m)	12	15
Coefficient of thermal expansion 10 ^-6 /℃	9.5	9.8
			Thermal conductivity w/(mk)	110	108
Average particle diameter (um)	15-17	16-18
			Application range	Continuous casting graphite	Continuous casting graphite

From the test results in table 1, it can be seen that: the copper pipe molding continuous casting graphite has good physical, mechanical and chemical properties, and has high flexural strength reaching 50MPa or more; the compressive strength is good and reaches 85MPa or more; the hardness is high, and the Shore hardness reaches 70; the resistivity is low and is lower than 12uΩ m; low thermal expansion coefficient of less than 9.5X10 ^-6 a/DEG C; the thermal conductivity is high and reaches 110 w/(mk). The continuous casting graphite material has high wear resistance, good sealing performance and good heat conduction in the use process.

The terminology used herein is for the purpose of description and illustration only and is not intended to be limiting. As the present invention may be embodied in several forms without departing from the spirit or essential attributes thereof, it should be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalences of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims

1. The preparation method of the continuous casting graphite material is characterized by comprising the following steps:

1) Firstly, preparing raw materials according to the following weight portions:

then, adding continuous casting graphite raw materials such as asphalt coke, petroleum coke, artificial graphite and spray carbon black into a kneading pot with the temperature kept at 90-100 ℃ for first kneading treatment; uniformly mixing to obtain an asphalt coke-petroleum coke-graphite-carbon black mixture; then adding raw materials of sulfur and molybdenum disulfide, heating and raising the temperature, and carrying out second kneading treatment; after uniform mixing, heating to 160-200 ℃, adding modified asphalt under the condition of keeping the temperature in a kneading pot to 160-200 ℃, and carrying out third kneading treatment to obtain a kneading mixture;

2) Crushing the kneaded mixture, and sieving to obtain mixed crushed materials;

7) Placing the first sintered blank into an impregnating tank for vacuumizing treatment until the vacuum degree in the impregnating tank is lower than 5torr, adding molten medium-temperature asphalt into the impregnating tank, and then performing pressurizing-impregnating treatment to obtain an impregnated blank;

2. The method of claim 1, wherein the first kneading treatment temperature in step 1) is 90-100 ℃; the second kneading treatment temperature is 160-180 ℃; the third kneading treatment temperature is 160-200 ℃.

3. The process according to claim 1 or 2, wherein the mixed crushed material in step 2) has a particle size of 40 mesh or less.

4. The method according to claim 1 or 2, wherein the pressure of the pressing treatment in step 4) is 2 to 6MPa; the pressing treatment time is 25-40min.

5. The method according to claim 1 or 2, wherein the pressure of the pressing treatment in step 4) is 2 to 5MPa.

6. The method of claim 1 or 2, wherein the first sintering treatment temperature in step 6) is 900-1000 ℃; the first sintering treatment time is 25-30 days.

7. The method of claim 1 or 2, wherein the first sintering treatment temperature in step 6) is 900-950 ℃; the first sintering treatment time was 25 days.

8. The method according to claim 1 or 2, wherein the relative pressure of the pressure-impregnation treatment in step 7) is 2 to 3.5MP; the pressure-impregnation treatment time is 8-10h.

9. The method according to claim 1 or 2, wherein the relative pressure of the pressure-impregnation treatment in step 7) is 2 to 3.0MPa; the press-impregnation treatment time was 9 hours.

10. The method according to claim 1 or 2, wherein the molten medium-temperature pitch is fed into the impregnation tank after the vacuum degree in the impregnation tank reaches 3 to 5torr in step 7), and then the pressurization-impregnation treatment is performed.

11. The method of claim 1 or 2, wherein the temperature of the second sintering treatment in step 8) is 900-1000 ℃; the second sintering time is 35-45 days.

12. The method of claim 1 or 2, wherein the temperature of the second sintering treatment in step 8) is 900-950 ℃; the second sintering time was 40 days.

13. The method of claim 1 or 2, wherein the graphitization treatment in step 9) is performed at a temperature of 2700 ℃ to 2800 ℃; the graphitization treatment time is 600-650h.

14. The method according to claim 1 or 2, wherein the graphitization treatment time in step 9) is 600 hours.

15. A continuous casting graphite material, characterized in that it is prepared according to the method as claimed in any one of claims 1 to 14.