High-purity isostatic graphite and preparation process thereof

Abstract

The invention discloses high-purity isostatic graphite and a preparation process thereof, and relates to the technical field of graphite, and the high-purity isostatic graphite is prepared from the following components: modified asphalt, petroleum coke, graphite powder, polyvinyl alcohol and water; the modified asphalt is formed by performing intercalation modification on Esox70 # matrix asphalt; the prepared isostatic pressing graphite can be made into product materials with large specifications, and the application requirements of large-scale equipment can be met. According to the preparation method, the raw material components are adjusted, the modified asphalt is introduced, and the specific preparation method is matched, so that the isostatic pressing graphite with a more uniform organization structure can be obtained, and the overall performance of the isostatic pressing graphite is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of graphite, in particular to high-purity isostatic graphite and a preparation process thereof. Background Art

[0002] In today's world of rapid development of high technology, various new materials emerge one after another. Among them, isostatic graphite has become an indispensable important material in many industries due to its unique properties and wide application fields. Isostatic graphite is a new type of graphite material developed in the 1960s and is widely used in metallurgy, chemistry, electricity, aerospace and atomic energy industries.

[0003] Isostatic graphite has good heat resistance. Compared with ordinary graphite, it has a fine and dense structure, good uniformity, a very low thermal expansion coefficient, excellent thermal shock resistance, isotropy, strong chemical corrosion resistance, good thermal and electrical conductivity, and excellent machining performance.

[0004] Due to its unique properties, isostatic graphite has a wide range of applications in many industries, including the following:

[0005] 1. Metallurgical field: used in smelting, forming and sintering processes in the metal industry, such as making graphite crucibles, special graphite molds, etc.

[0006] 2. Mechanical field: As a material for lubricating and sealing parts such as sealing rings, bearings, and seals, it improves the operating efficiency and stability of mechanical equipment.

[0007] 3. Electronic field: used in high temperature processing of electronic components, such as the manufacture of diodes.

[0008] 4. Photovoltaic field: used as graphite thermal field components in single crystal silicon growth furnaces and polycrystalline silicon ingot furnaces, such as heating elements, crucibles, etc.

[0009] 5. Nuclear industry: As a material for key components such as deceleration materials and reflective materials in nuclear reactors, it provides strong support for the development of nuclear energy.

[0010] However, the flexural strength and compressive strength of isostatic graphite prepared by the prior art are generally poor. In order to further expand its application field, further improvements are made to it.

[0011] Based on this, a high-purity isostatic graphite and a preparation process thereof are provided to solve the existing technical problems. Summary of the invention

[0012] The object of the present invention is to provide a high-purity isostatic graphite and a preparation process thereof, so as to solve the deficiencies in the prior art.

[0013] The technical solution adopted by the present invention is as follows:

[0014] A high-purity isostatic graphite, comprising the following components by weight: 15-22 parts of modified asphalt, 13-18 parts of petroleum coke, 20-24 parts of graphite powder, 3-5 parts of polyvinyl alcohol, and 18-20 parts of water;

[0015] The modified asphalt is prepared by intercalation modification of Esso 70# base asphalt.

[0016] As a further technical solution: the modified asphalt preparation method is:

[0017] (1) First, Esso 70# base asphalt and activated EPDM rubber powder are mixed together to obtain a mixture;

[0018] Among them, the stirring speed is 100r / min;

[0019] The stirring time is 30 minutes;

[0020] (2) heating the mixture to 190° C., stirring at this temperature for 10 min, and then shearing it again for 1.5 hours to obtain a preliminary sheared material;

[0021] (3) The primary sheared material is placed at 210°C for 15-18 hours, and then subjected to secondary shearing treatment for 40 minutes. After cooling to room temperature, the modified asphalt is obtained.

[0022] As a further technical solution: the preparation method of the activated EPDM rubber powder is:

[0023] First, spread the EPDM rubber powder evenly in the low-temperature plasma chamber, evacuate to 0.5 Pa, then start the power supply, perform low-temperature plasma treatment for 5-6 minutes, and then take it out.

[0024] As a further technical solution: the low-temperature plasma processing gas is helium.

[0025] As a further technical solution: the mass ratio of the Esso 70# base asphalt to the activated EPDM rubber powder is 10:2-3.

[0026] As a further technical solution: the primary shearing speed is 5000 rpm;

[0027] The secondary shearing speed is 6500 rpm.

[0028] As a further technical solution: the petroleum coke has a carbon-to-hydrogen ratio of 21, a relative density of 1.0, an ash content of 0.35%, and a volatile matter content of 5%.

[0029] A method for preparing high-purity isostatic graphite comprises the following steps:

[0030] S1: weigh the raw material components according to their weight: modified asphalt, petroleum coke, graphite powder, polyvinyl alcohol, and water;

[0031] S2: adding each raw material component to a mixer in sequence, and then stirring and mixing to obtain a mixed raw material;

[0032] Among them, the stirring speed is 350r / min;

[0033] The stirring time is 20 minutes;

[0034] S3: adding the mixed raw materials obtained above into a grinder for grinding, and after the grinding process, a grind is obtained;

[0035] S4 adds the abrasive material into the mold, and after preliminary drying, obtains a preliminary blank;

[0036] S5, performing preliminary calcination treatment on the preliminary blank under a certain pressure to obtain a primary blank;

[0037] Among them, the pressure is 120-150MPa;

[0038] S6: continuing isostatic pressing the primary blank at an isostatic pressing pressure of 550-560 MPa to obtain a secondary blank;

[0039] S7 performs graphitization treatment on the secondary blank, and cools it to obtain isostatic graphite.

[0040] As a further technical solution: the grinding process is performed at a rotation speed of 1000 r / min and a time of 1 hour;

[0041] The initial drying temperature is 150°C and the time is 40 minutes.

[0042] As a further technical solution: the preliminary calcination treatment temperature is 600-620°C and the time is 2 hours;

[0043] The graphitization treatment is carried out at 2200-2300° C. for 55-58 hours.

[0044] Beneficial effects:

[0045] The isostatically pressed graphite prepared by the present invention can be made into product materials with larger specifications and can meet the application requirements of large-scale equipment.

[0046] The present invention adjusts the raw material components, introduces modified asphalt, and cooperates with a specific preparation method to obtain isostatic graphite with a more uniform organizational structure, thereby greatly improving the overall performance of the isostatic graphite.

[0047] Under high pressure, isostatic graphite with higher density and strength can be obtained, which will be more stable and reliable during the working process, thus broadening its application areas.

[0048] Through the introduction of modified asphalt, it can act as a binder to make the components more tightly bonded under high pressure. During the pressing process, the fluidity of modified asphalt can form a more uniform and dense microstructure, thereby greatly improving the strength of isostatic graphite, especially the compressive strength and flexural strength, and greatly broadening its application areas.

[0049] During the roasting process, the modified asphalt is carbonized and can fill the pores in the material, thereby further improving the density and comprehensive performance of the formed isostatic graphite. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a bar graph of the flexural strength of each sample in the test. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Example 1

[0053] A method for preparing high-purity isostatic graphite comprises the following steps:

[0054] S1 weighed the raw material components according to their weight: 15 parts of modified asphalt, 13 parts of petroleum coke, 20 parts of graphite powder, 3 parts of polyvinyl alcohol, and 18 parts of water;

[0055] The modified asphalt is prepared by intercalation modification of Esso 70# base asphalt.

[0056] The preparation method of modified asphalt is:

[0057] (1) First, Esso 70# base asphalt and activated EPDM rubber powder are mixed together to obtain a mixture;

[0058] Among them, the stirring speed is 100r / min;

[0059] The stirring time is 30 minutes;

[0060] (2) heating the mixture to 190° C., stirring at this temperature for 10 min, and then shearing it again for 1.5 hours to obtain a preliminary sheared material;

[0061] (3) The primary sheared material is placed at 210°C for 15 hours, and then subjected to secondary shearing treatment for 40 minutes. After cooling to room temperature, modified asphalt is obtained.

[0062] The preparation method of activated EPDM rubber powder is as follows:

[0063] First, spread the EPDM rubber powder evenly in the low-temperature plasma chamber, evacuate to 0.5 Pa, then start the power supply, perform low-temperature plasma treatment for 5-6 minutes, and then take it out.

[0064] The low temperature plasma treatment gas is helium.

[0065] The mass ratio of Esso 70# base asphalt and activated EPDM rubber powder is 10:2.

[0066] The primary shearing speed is 5000rpm;

[0067] The secondary shearing speed is 6500 rpm.

[0068] The carbon-to-hydrogen ratio of petroleum coke is 21, the relative density is 1.0, the ash content is 0.35%, and the volatile matter is 5%.

[0069] S2: adding each raw material component to a mixer in sequence, and then stirring and mixing to obtain a mixed raw material;

[0070] Among them, the stirring speed is 350r / min;

[0071] The stirring time is 20 minutes;

[0072] S3: adding the mixed raw materials obtained above into a grinder for grinding, and after the grinding process, a grind is obtained;

[0073] S4 adds the abrasive material into the mold, and after preliminary drying, obtains a preliminary blank;

[0074] S5, performing preliminary calcination treatment on the preliminary blank under a certain pressure to obtain a primary blank;

[0075] Among them, the pressure is 120MPa;

[0076] S6: isostatic pressing the primary blank further at an isostatic pressing pressure of 550 MPa to obtain a secondary blank;

[0077] S7 performs graphitization treatment on the secondary blank, and cools it to obtain isostatic graphite.

[0078] The grinding speed was 1000 r / min and the time was 1 hour;

[0079] The initial drying temperature is 150°C and the time is 40 minutes.

[0080] The initial calcination treatment temperature is 600°C and the time is 2 hours;

[0081] The graphitization treatment was performed at 2200° C. for 55 hours.

[0082] Example 2

[0083] A method for preparing high-purity isostatic graphite comprises the following steps:

[0084] S1 weighed the raw material components according to their weight: 18 parts of modified asphalt, 14 parts of petroleum coke, 21 parts of graphite powder, 4 parts of polyvinyl alcohol, and 19 parts of water;

[0085] The modified asphalt is prepared by intercalation modification of Esso 70# base asphalt.

[0086] The preparation method of modified asphalt is:

[0087] (1) First, Esso 70# base asphalt and activated EPDM rubber powder are mixed together to obtain a mixture;

[0088] Among them, the stirring speed is 100r / min;

[0089] The stirring time is 30 minutes;

[0090] (2) heating the mixture to 190° C., stirring at this temperature for 10 min, and then shearing it again for 1.5 hours to obtain a preliminary sheared material;

[0091] (3) The primary sheared material is placed at 210°C for 16 hours, and then subjected to secondary shearing treatment for 40 minutes. After cooling to room temperature, the modified asphalt is obtained.

[0092] The preparation method of activated EPDM rubber powder is as follows:

[0093] First, spread the EPDM rubber powder evenly in the low-temperature plasma chamber, evacuate to 0.5 Pa, then start the power supply, perform low-temperature plasma treatment for 5 minutes, and then take it out.

[0094] The low temperature plasma treatment gas is helium.

[0095] The mass ratio of Esso 70# base asphalt and activated EPDM rubber powder is 10:2.

[0096] The primary shearing speed is 5000rpm;

[0097] The secondary shearing speed is 6500 rpm.

[0098] The carbon-to-hydrogen ratio of petroleum coke is 21, the relative density is 1.0, the ash content is 0.35%, and the volatile matter is 5%.

[0099] S2: adding each raw material component to a mixer in sequence, and then stirring and mixing to obtain a mixed raw material;

[0100] Among them, the stirring speed is 350r / min;

[0101] The stirring time is 20 minutes;

[0102] S3: adding the mixed raw materials obtained above into a grinder for grinding, and after the grinding process, a grind is obtained;

[0103] S4 adds the abrasive material into the mold, and after preliminary drying, obtains a preliminary blank;

[0104] S5, performing preliminary calcination treatment on the preliminary blank under a certain pressure to obtain a primary blank;

[0105] Among them, the pressure is 125MPa;

[0106] S6: the primary blank is further isostatically pressed at an isostatic pressing pressure of 552 MPa to obtain a secondary blank;

[0107] S7 performs graphitization treatment on the secondary blank, and cools it to obtain isostatic graphite.

[0108] The grinding speed was 1000 r / min and the time was 1 hour;

[0109] The initial drying temperature is 150°C and the time is 40 minutes.

[0110] The initial calcination treatment temperature is 610°C and the time is 2 hours;

[0111] The graphitization treatment was performed at 2250° C. for 56 hours.

[0112] Example 3

[0113] A method for preparing high-purity isostatic graphite comprises the following steps:

[0114] S1 weighed the raw material components according to their weight: 17 parts of modified asphalt, 15 parts of petroleum coke, 23 parts of graphite powder, 4 parts of polyvinyl alcohol, and 19 parts of water;

[0115] The modified asphalt is prepared by intercalation modification of Esso 70# base asphalt.

[0116] The preparation method of modified asphalt is:

[0117] (1) First, Esso 70# base asphalt and activated EPDM rubber powder are mixed together to obtain a mixture;

[0118] Among them, the stirring speed is 100r / min;

[0119] The stirring time is 30 minutes;

[0120] (2) heating the mixture to 190° C., stirring at this temperature for 10 min, and then shearing it again for 1.5 hours to obtain a preliminary sheared material;

[0121] (3) The primary sheared material is placed at 210°C for 16 hours, and then subjected to secondary shearing treatment for 40 minutes. After cooling to room temperature, the modified asphalt is obtained.

[0122] The preparation method of activated EPDM rubber powder is as follows:

[0123] First, spread the EPDM rubber powder evenly in the low-temperature plasma chamber, evacuate to 0.5 Pa, then start the power supply, perform low-temperature plasma treatment for 5 minutes, and then take it out.

[0124] The low temperature plasma treatment gas is helium.

[0125] The mass ratio of Esso 70# base asphalt and activated EPDM rubber powder is 10:3.

[0126] The primary shearing speed is 5000rpm;

[0127] The secondary shearing speed is 6500 rpm.

[0128] The carbon-to-hydrogen ratio of petroleum coke is 21, the relative density is 1.0, the ash content is 0.35%, and the volatile matter is 5%.

[0129] S2: adding each raw material component to a mixer in sequence, and then stirring and mixing to obtain a mixed raw material;

[0130] Among them, the stirring speed is 350r / min;

[0131] The stirring time is 20 minutes;

[0132] S3: adding the mixed raw materials obtained above into a grinder for grinding, and after the grinding process, a grind is obtained;

[0133] S4 adds the abrasive material into the mold, and after preliminary drying, obtains a preliminary blank;

[0134] S5, performing preliminary calcination treatment on the preliminary blank under a certain pressure to obtain a primary blank;

[0135] Among them, the pressure is 130MPa;

[0136] S6: the primary blank is further isostatically pressed at an isostatic pressing pressure of 558 MPa to obtain a secondary blank;

[0137] S7 performs graphitization treatment on the secondary blank, and cools it to obtain isostatic graphite.

[0138] The grinding speed was 1000 r / min and the time was 1 hour;

[0139] The initial drying temperature is 150°C and the time is 40 minutes.

[0140] The initial calcination treatment temperature is 618°C and the time is 2 hours;

[0141] The graphitization treatment was performed at 2230° C. for 56 hours.

[0142] Example 4

[0143] A method for preparing high-purity isostatic graphite comprises the following steps:

[0144] S1 weighed the raw material components according to their weight: 20 parts of modified asphalt, 17 parts of petroleum coke, 23 parts of graphite powder, 4 parts of polyvinyl alcohol, and 20 parts of water;

[0145] The modified asphalt is prepared by intercalation modification of Esso 70# base asphalt.

[0146] The preparation method of modified asphalt is:

[0147] (1) First, Esso 70# base asphalt and activated EPDM rubber powder are mixed together to obtain a mixture;

[0148] Among them, the stirring speed is 100r / min;

[0149] The stirring time is 30 minutes;

[0150] (2) heating the mixture to 190° C., stirring at this temperature for 10 min, and then shearing it again for 1.5 hours to obtain a preliminary sheared material;

[0151] (3) The primary sheared material is placed at 210°C for 18 hours, and then subjected to secondary shearing treatment for 40 minutes. After cooling to room temperature, modified asphalt is obtained.

[0152] The preparation method of activated EPDM rubber powder is as follows:

[0153] First, spread the EPDM rubber powder evenly in the low-temperature plasma chamber, evacuate to 0.5 Pa, then start the power supply, perform low-temperature plasma treatment for 6 minutes, and then take it out.

[0154] The low temperature plasma treatment gas is helium.

[0155] The mass ratio of Esso 70# base asphalt and activated EPDM rubber powder is 10:3.

[0156] The primary shearing speed is 5000rpm;

[0157] The secondary shearing speed is 6500 rpm.

[0158] The carbon-to-hydrogen ratio of petroleum coke is 21, the relative density is 1.0, the ash content is 0.35%, and the volatile matter is 5%.

[0159] S2: adding each raw material component to a mixer in sequence, and then stirring and mixing to obtain a mixed raw material;

[0160] Among them, the stirring speed is 350r / min;

[0161] The stirring time is 20 minutes;

[0162] S3: adding the mixed raw materials obtained above into a grinder for grinding, and after the grinding process, a grind is obtained;

[0163] S4 adds the abrasive material into the mold, and after preliminary drying, obtains a preliminary blank;

[0164] S5, performing preliminary calcination treatment on the preliminary blank under a certain pressure to obtain a primary blank;

[0165] Among them, the pressure is 140MPa;

[0166] S6: isostatic pressing the primary blank further at an isostatic pressing pressure of 553 MPa to obtain a secondary blank;

[0167] S7 performs graphitization treatment on the secondary blank, and cools it to obtain isostatic graphite.

[0168] The grinding speed was 1000 r / min and the time was 1 hour;

[0169] The initial drying temperature is 150°C and the time is 40 minutes.

[0170] The initial calcination treatment temperature is 608°C and the time is 2 hours;

[0171] The graphitization treatment was performed at 2270° C. for 55 hours.

[0172] Example 5

[0173] A method for preparing high-purity isostatic graphite comprises the following steps:

[0174] S1 weighed the raw material components according to their weight: 22 parts of modified asphalt, 18 parts of petroleum coke, 24 parts of graphite powder, 5 parts of polyvinyl alcohol, and 20 parts of water;

[0175] The modified asphalt is prepared by intercalation modification of Esso 70# base asphalt.

[0176] The preparation method of modified asphalt is:

[0177] (1) First, Esso 70# base asphalt and activated EPDM rubber powder are mixed together to obtain a mixture;

[0178] Among them, the stirring speed is 100r / min;

[0179] The stirring time is 30 minutes;

[0180] (2) heating the mixture to 190° C., stirring at this temperature for 10 min, and then shearing it again for 1.5 hours to obtain a preliminary sheared material;

[0181] (3) The primary sheared material is placed at 210°C for 18 hours, and then subjected to secondary shearing treatment for 40 minutes. After cooling to room temperature, modified asphalt is obtained.

[0182] The preparation method of activated EPDM rubber powder is as follows:

[0183] First, spread the EPDM rubber powder evenly in the low-temperature plasma chamber, evacuate to 0.5 Pa, then start the power supply, perform low-temperature plasma treatment for 6 minutes, and then take it out.

[0184] The low temperature plasma treatment gas is helium.

[0185] The mass ratio of Esso 70# base asphalt and activated EPDM rubber powder is 10:3.

[0186] The primary shearing speed is 5000rpm;

[0187] The secondary shearing speed is 6500 rpm.

[0188] The carbon-to-hydrogen ratio of petroleum coke is 21, the relative density is 1.0, the ash content is 0.35%, and the volatile matter is 5%.

[0189] S2: adding each raw material component to a mixer in sequence, and then stirring and mixing to obtain a mixed raw material;

[0190] Among them, the stirring speed is 350r / min;

[0191] The stirring time is 20 minutes;

[0192] S3: adding the mixed raw materials obtained above into a grinder for grinding, and after the grinding process, a grind is obtained;

[0193] S4 adds the abrasive material into the mold, and after preliminary drying, obtains a preliminary blank;

[0194] S5, performing preliminary calcination treatment on the preliminary blank under a certain pressure to obtain a primary blank;

[0195] Among them, the pressure is 150MPa;

[0196] S6: the primary blank is further isostatically pressed at an isostatic pressing pressure of 560 MPa to obtain a secondary blank;

[0197] S7 performs graphitization treatment on the secondary blank, and cools it to obtain isostatic graphite.

[0198] The grinding speed was 1000 r / min and the time was 1 hour;

[0199] The initial drying temperature is 150°C and the time is 40 minutes.

[0200] The initial calcination treatment temperature is 620°C and the time is 2 hours;

[0201] The graphitization treatment was performed at 2300° C. for 58 hours.

[0202] Comparative Example 1:

[0203] The difference from Example 1 is that modified asphalt is not added, and the rest of the technical solutions remain unchanged.

[0204] Comparative Example 2

[0205] The difference from Example 1 is that the modified asphalt is replaced by untreated asphalt, and the rest of the technical solutions remain unchanged.

[0206] test:

[0207] Esso 70# base asphalt parameters:

[0208] Table 1

[0209] Technical indicators result 25℃ Needle penetration (0.1mm) 72 Softening point℃ 47 15℃ elongation cm 155

[0210] The bulk density of the isostatically pressed graphite sample of the embodiment was tested according to GB / T24528-2009 "Determination of bulk density of carbon materials":

[0211] Table 2

[0212]

[0213]

[0214] It can be seen from Table 2 that the isostatically pressed graphite prepared in the present invention has a relatively suitable bulk density.

[0215] The compressive strength and flexural strength tests were performed on the samples of the embodiment and the comparative example:

[0216] The compressive strength refers to GB / T1431-2019 "Determination method of compressive strength of carbon materials";

[0217] The flexural strength refers to GB / T3074.1-2021 "Determination method of flexural strength of carbon materials":

[0218] Table 3

[0219] Compressive strength MPa Flexural strength MPa Example 1 133.3 76.6 Example 2 133.9 77.0 Example 3 134.5 77.3 Example 4 133.4 76.2 Example 5 132.8 75.3 Comparative Example 1 102.5 55.4 Comparative Example 2 119.7 66.9

[0220] It can be seen from Table 3 that the isostatic graphite prepared in the present invention has excellent mechanical properties.

[0221] The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification, should be within the protection scope of the present invention.

Claims

1. A high-purity isostatic graphite, characterized in that: The following ingredients are included by weight: 15-22 parts of modified asphalt, 13-18 parts of petroleum coke, 20-24 parts of graphite powder, 3-5 parts of polyvinyl alcohol, and 18-20 parts of water; The modified asphalt is prepared by intercalation modification of Esso 70# base asphalt.

2. The high-purity isostatic graphite according to claim 1, characterized in that: The modified asphalt preparation method is: (1) First, Esso 70# base asphalt and activated EPDM rubber powder are mixed together to obtain a mixture; Among them, the stirring speed is 100r / min; The stirring time is 30 minutes; (2) The mixed material is heated to 190° C., stirred at this temperature for 10 min, and then sheared again for 1.5 hours to obtain a preliminary sheared material; (3) The primary sheared material is placed at 210°C for 15-18 hours, and then subjected to secondary shearing treatment for 40 minutes. After cooling to room temperature, modified asphalt is obtained.

3. A high-purity isostatic graphite according to claim 2, characterized in that: The preparation method of the activated EPDM rubber powder is as follows: First, spread the EPDM rubber powder evenly in the low-temperature plasma chamber, evacuate to 0.5 Pa, then start the power supply, perform low-temperature plasma treatment for 5-6 minutes, and then take it out.

4. The high-purity isostatic graphite according to claim 3, characterized in that: The low temperature plasma processing gas is helium.

5. The high-purity isostatic graphite according to claim 4, characterized in that: The mass ratio of the Esso 70# base asphalt to the activated EPDM rubber powder is 10:2-3.

6. The high-purity isostatic graphite according to claim 4, characterized in that: The primary shearing speed is 5000 rpm; The secondary shearing speed is 6500 rpm.

7. The high-purity isostatic graphite according to claim 4, characterized in that: The petroleum coke has a carbon-to-hydrogen ratio of 21, a relative density of 1.0, an ash content of 0.35%, and a volatile matter content of 5%.

8. The method for preparing high-purity isostatic graphite according to claim 1, characterized in that: The following steps are involved: S1: weigh the raw material components according to their weight: modified asphalt, petroleum coke, graphite powder, polyvinyl alcohol, and water; S2: adding each raw material component to a mixer in sequence, and then stirring and mixing to obtain a mixed raw material; Among them, the stirring speed is 350r / min; The stirring time is 20 minutes; S3: adding the mixed raw materials obtained above into a grinder for grinding, and after the grinding process, a grind is obtained; S4 adds the abrasive material into the mold, and after preliminary drying, obtains a preliminary blank; S5, performing preliminary calcination treatment on the preliminary blank under a certain pressure to obtain a primary blank; Among them, the pressure is 120-150MPa; S6: continuing isostatic pressing the primary blank at an isostatic pressing pressure of 550-560 MPa to obtain a secondary blank; S7 performs graphitization treatment on the secondary blank, and cools it to obtain isostatic graphite.

9. The method for preparing high-purity isostatic graphite according to claim 8, characterized in that: The grinding process was performed at a rotation speed of 1000 r / min and a time of 1 hour; The initial drying temperature is 150°C and the time is 40 minutes.

10. The method for preparing high-purity isostatic graphite according to claim 8, characterized in that: The preliminary calcination treatment temperature is 600-620°C and the time is 2 hours; The graphitization treatment is carried out at 2200-2300° C. for 55-58 hours.

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