A method of processing artificial graphite oversize

Abstract

The application discloses a processing method of artificial graphite secondary oversize, which comprises the following steps: (1) the artificial graphite secondary oversize is sequentially subjected to scattering treatment and grading treatment to obtain material A; (2) the material A is mixed with artificial graphite semi-finished product, and is subjected to graphitization treatment to obtain material B; (3) the material B is mixed with modified asphalt, and is subjected to carbonization treatment to obtain material C; and (4) the material C is subjected to finished product processing treatment to obtain artificial graphite negative electrode material after processing. The processing method further mixes the material after scattering and grading with the artificial graphite semi-finished product in normal production, and then performs graphitization and high-temperature carbonization, so that the electrochemical performance of the material, such as specific surface area, tap density and powder compaction density, is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery materials, in particular to a processing method of artificial graphite secondary oversize. BACKGROUND

[0002] During the processing of artificial graphite, some unqualified materials will inevitably appear, among which the most regrettable is the oversize after processing. From the performance point of view, it has a discharge capacity close to the finished product, but its particle size is too large and the morphology is irregular, which has a negative impact on the consistency of the battery. The primary oversize of artificial graphite is generally subjected to some simple physical treatment, such as shaping and screening, and then mixed in normal materials in a small proportion for delivery, but the secondary oversize has a larger particle size and cannot be simply dispersed for reuse. Therefore, it is necessary to develop a method to process the artificial graphite secondary oversize to meet the delivery requirements of normal products.

[0003] CN115814921A discloses a processing method of artificial graphite oversize. The oversize of the sieved artificial graphite material is transported to the storage bin of the rod pin mill disperser, and the disperser is used for dispersing. The main frequency of the disperser is 20-100Hz, the rotating speed is 1000-3000r / min, the feeding frequency is 3-18Hz, and the dispersing efficiency is 1500-2500Kg / h. The dispersed material is classified, and the feeding frequency is 3-16Hz and the fan frequency is 20-60Hz during classification. The classification efficiency is 200-600Kg / h. The process of rod pin mill dispersing + classification is used to process artificial graphite oversize, which is simple, easy to operate, has little damage to the external structure of the material, high oversize yield and high product qualification rate. The qualified oversize is used as a negative material of lithium battery, which exhibits excellent electrochemical performance, and the initial capacity can reach 363.6mAh / g.

[0004] However, the utilization efficiency of the existing artificial graphite secondary oversize after processing is low, and a processing method for processing the secondary oversize into artificial graphite negative material that can be normally used is urgently needed. SUMMARY

[0005] The technical problem solved by the present application is to overcome the low utilization efficiency of the existing artificial graphite secondary oversize after processing, and to provide a new processing method for processing the secondary oversize into artificial graphite negative material that can be normally used. The processed material is further mixed with the normal artificial graphite semi-finished product, and then subjected to graphitization and high-temperature carbonization, thereby improving the electrochemical performance of the material, such as specific surface area, tap density and powder compaction density.

[0006] The present application provides the following technical solutions to solve the above problems.

[0007] The application provides a processing method of artificial graphite secondary oversize, which comprises the following steps:

[0008] (1) the artificial graphite secondary oversize is sequentially subjected to scattering treatment and grading treatment to obtain material A;

[0009] (2) the material A is mixed with artificial graphite semi-finished product, and is subjected to graphitization treatment to obtain material B;

[0010] (3) the material B is mixed with modified pitch, and is subjected to carbonization treatment to obtain material C;

[0011] (4) the material C is subjected to finished product processing treatment to obtain the artificial graphite negative electrode material after processing.

[0012] In the application, the artificial graphite can be conventional artificial graphite in the art, and preferably one or more of pitch coke, petroleum coke and coal-based coke, for example, petroleum coke.

[0013] In the application, the artificial graphite secondary oversize refers to the substance that cannot pass through the sieve hole after two times of screening treatment of artificial graphite, and can be prepared by conventional methods in the art, preferably by the following method:

[0014] (a) the artificial graphite raw material is subjected to crushing treatment to obtain powder a;

[0015] (b) the powder a is subjected to shaping treatment to obtain powder b;

[0016] (c) the powder b is mixed with pitch to perform granulation treatment to obtain powder c;

[0017] (d) the powder c is subjected to graphitization treatment to obtain powder d;

[0018] (e) the powder d is mixed with modified pitch to perform carbonization treatment to obtain powder e;

[0019] (f) the powder e is subjected to finished product processing treatment to obtain the artificial graphite secondary oversize.

[0020] In the application, the operations and conditions of the crushing treatment, the shaping treatment, the granulation treatment, the graphitization treatment, the carbonization treatment and the finished product processing treatment can be conventional operations and conditions in the art, and the application is particularly preferred to be the following conditions.

[0021] In step (a), the particle size of the powder a is preferably not more than 100 μm.

[0022] In step (a), before the crushing treatment, the raw material is preferably subjected to crushing by a crusher.

[0023] The particle size of the raw material after crushing is preferably not more than 10 mm.

[0024] In step (b), the particle size of the powder b is 6-8 μm.

[0025] In step (b), the powder a is subjected to a primary classification treatment before the shaping treatment. The primary classification treatment is aimed at removing the particles with too large or too small particle size from the powder a, so as to control the particle size within 6-8 μm.

[0026] In step (b), the shaping is performed twice.

[0027] In step (c), the granulation treatment can be performed in a conventional granulation device in the art, which is preferably a reaction kettle.

[0028] In step (c), the asphalt can be a conventional asphalt in the art, which is preferably purchased from Sinopec.

[0029] In step (c), the particle size D50 of the asphalt is preferably 3.3-5.5 μm, for example, 3.71 μm.

[0030] In step (c), the coking value of the asphalt is preferably 60-75%, for example, 67%.

[0031] In step (c), the amount of the asphalt is preferably 18% of the total mass of the powder b and the asphalt.

[0032] In step (d), the graphitization treatment can be performed in a conventional reaction vessel in the art, which is preferably a box furnace.

[0033] In step (d), the temperature of the graphitization treatment is 2800-3000 °C, for example, 3000 °C.

[0034] In step (e), the carbonization treatment can be performed in a conventional reaction vessel in the art, which is preferably a kiln.

[0035] In step (e), the temperature of the carbonization treatment is 1000-1200 °C, for example, 1200 °C.

[0036] In step (e), the modified asphalt can be a common modified asphalt on the market (purchased from Sinopec).

[0037] In step (e), the particle size of the modified asphalt is preferably 3-6 μm, for example, 4 μm.

[0038] In step (e), the coking value of the modified asphalt is preferably not higher than 30%, for example, 30%.

[0039] In step (e), the density of the modified asphalt at 30 °C is preferably 1.05-1.1 g / cm3 for example 1.07 g / cm 3 .

[0040] In step (e), the amount of the modified asphalt is 10%-30% of the total mass of the powder d and the modified asphalt, for example 15%.

[0041] In step (e), the powder d is preferably mixed with the modified asphalt until uniform.

[0042] In step (e), the powder d is preferably mixed with the modified asphalt until uniform.

[0043] In step (f), the finished product processing treatment comprises the steps of screening and demagnetizing the powder e.

[0044] In step (f), the screening can be performed in a conventional screening device in the art, which is preferably an air flow screen.

[0045] In step (f), the particle size of the air flow screen is preferably 270 mesh.

[0046] In step (f), the number of screenings is preferably twice.

[0047] In step (f), the demagnetization can be performed in a conventional demagnetizer in the art.

[0048] In step (f), the number of demagnetizations is preferably twice.

[0049] In step (1), the dispersing treatment can be performed in a conventional dispersing machine in the art.

[0050] In step (1), the main frequency of the dispersing machine is 20-40 Hz, for example 30 Hz.

[0051] In step (1), the rotational speed of the dispersing machine is 300-1200 r / min, for example 600 r / min.

[0052] In step (1), the feeding frequency of the dispersing machine is 5-10 Hz, for example 10 Hz.

[0053] In step (1), the dispersing efficiency of the dispersing machine is 300-1500 Kg / h, for example 750 Kg / h.

[0054] In step (1), the grading treatment can be performed in a conventional grading machine in the art.

[0055] In step (1), the feeding frequency of the grading machine is 3-10 Hz, for example 8 Hz.

[0056] In step (1), the fan frequency of the grading machine is 20-50 Hz, for example 25 Hz.

[0057] The classification efficiency of the classifier is 150-500 Kg / h, for example, 200 Kg / h.

[0058] In step (1), the particle size D50 of the material A is 11.5-14.5 μm, for example, 13 μm.

[0059] In step (2), the temperature of the graphitization treatment is 2800-3000 ℃, for example, 3000 ℃.

[0060] In step (2), the amount of the artificial graphite semi-finished product is 10%-30% of the total mass of the material A and the artificial graphite semi-finished product, for example, 15%.

[0061] The artificial graphite semi-finished product is prepared by sequentially performing the above steps (a)-(d).

[0062] In step (3), the amount of the modified asphalt is 10%-30% of the total mass of the material B and the modified asphalt, for example, 15%.

[0063] In step (3), the temperature of the carbonization treatment is 1000-1200 ℃, for example, 1200 ℃.

[0064] In step (3), the material B and the modified asphalt are preferably mixed until uniform.

[0065] The modified asphalt can be a common modified asphalt on the market (purchased from Sinopec).

[0066] The particle size of the modified asphalt is preferably 3-6 μm, for example, 4 μm.

[0067] The coking value of the modified asphalt is preferably not higher than 30%, for example, 30%.

[0068] The density of the modified asphalt at 30 ℃ is preferably 1.05-1.1 g / cm 3 , for example, 1.07 g / cm 3 .

[0069] The uniformly mixed material B and the modified asphalt are preferably stirred at room temperature for 1 h.

[0070] In step (4), the product processing treatment includes the steps of screening and removing magnetism of the material C.

[0071] The screening can be performed in a conventional screening device in the art, and the screening device is preferably an air flow screen.

[0072] The particle size of the air flow screen is preferably 270 mesh.

[0073] The number of times of screening is preferably twice.

[0074] The demagnetization can be performed using a conventional demagnetizer in the art.

[0075] Preferably, the demagnetization is performed twice.

[0076] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0077] The reagents and raw materials used in this invention are all commercially available.

[0078] The positive and progressive effects of this invention are as follows:

[0079] A novel processing method transforms secondary sieve oversize into usable artificial graphite anode material. This method is particularly effective when the secondary sieve oversize originates from products with high capacity requirements, as it can increase the capacity of the artificial graphite mixed with it. Furthermore, the method is simple to operate, easy to implement, and suitable for industrial production. Experimental results show that the artificial graphite anode material obtained using this method meets performance standards, effectively utilizing the previously unusable secondary sieve oversize. Attached Figure Description

[0080] Figure 1 Scanning electron microscope image of the material on the secondary sieve of artificial graphite in Comparative Example 2;

[0081] Figure 2 This is a scanning electron microscope image of the finished product after secondary sieve processing in Example 1. Detailed Implementation

[0082] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0083] In the embodiments, the artificial graphite that produces the secondary sieve residue and the artificial graphite obtained by blending and processing together are the same artificial graphite anode material. The finished artificial graphite product is characterized by a particle size D50 of 13.5-15.5 μm and a discharge capacity of 356 mAh / g.

[0084] Example 1

[0085] (1) Dispersion and grading: The material on the secondary sieve is dispersed using a disperser with a frequency of 30Hz, a rotation speed of 600r / min, a feeding frequency of 10Hz, and a dispersion efficiency of 750Kg / h; the dispersed material is then graded with a feeding frequency of 8Hz, a blower frequency of 25Hz, and a grading efficiency of 200Kg / h. The resulting material A has a particle size D50 of 13μm.

[0086] The preparation steps of the secondary sieve residue are as follows:

[0087] (a) crushing treatment: petroleum coke is crushed by a crusher and then crushed by a mechanical grinder to obtain powder a; wherein the particle size after crushing is not greater than 10 mm; the particle size after crushing is not greater than 100 μm.

[0088] (b) shaping treatment: powder a is classified according to particle size and then shaped twice to obtain powder b, wherein the particle size D50 of powder b is 6-8 μm, and the qualified particle size ratio is > 99%;

[0089] (c) granulation treatment: powder b and asphalt are uniformly mixed and granulated by a reaction kettle to obtain powder c, and the asphalt ratio is 18%; wherein the asphalt is ordinary asphalt (purchased from Sinopec), the D50 of which is 3.71 μm, and the coking value is 67%.

[0090] (d) graphitization treatment: powder c is graphitized at a temperature of 3000 ℃ in a box furnace to obtain powder d;

[0091] (e) carbonization treatment: powder d is uniformly mixed with modified asphalt, then stirred for 1 hour before entering the kiln, and then carbonized at 1200 ℃ to obtain powder e, and the amount of modified asphalt is 15% of the total mass of powder d and modified asphalt;

[0092] (f) finished product processing treatment: the carbonized powder e is screened twice and de-magnetized twice to obtain the secondary sieve residue.

[0093] (2) graphitization treatment: the dispersed and classified material A is mixed with a normal production artificial graphite semi-finished product in a box furnace at 3000 ℃ to obtain material B; wherein the amount of the artificial graphite semi-finished product is 15% of the total mass of material A and the artificial graphite semi-finished product;

[0094] wherein the normal production artificial graphite semi-finished product is prepared by sequentially performing the above steps (a)-(d).

[0095] (3) carbonization treatment: material B is uniformly mixed with modified asphalt, then stirred for 1 hour at room temperature before entering the kiln, and then carbonized at 1200 ℃ to obtain material C, wherein the amount of modified asphalt is 15% of the total mass of material B and modified asphalt, wherein the modified asphalt is a common modified asphalt on the market (purchased from Sinopec), the particle size D50 is 4 μm; the coking value is 30%; the density at 30 ℃ is 1.07 g / cm 3 .

[0096] (4) finished product processing treatment: the carbonized material C is screened twice and de-magnetized twice by using an air flow screen with a particle size of 270 mesh, and a normal performance artificial graphite negative electrode material is obtained, such as Figure 2SEM image of the obtained artificial graphite negative electrode material is shown in Figure 1.

[0097] Comparative Example 1

[0098] (1) Dispersing and grading: the secondary oversize obtained in steps (a)-(f) above was dispersed by a dispersing machine, wherein the frequency of the dispersing machine was 30 Hz, the rotating speed was 600 r / min, the feeding frequency was 10 Hz, and the dispersing efficiency was 750 Kg / h; the dispersed material was graded, wherein the feeding frequency was 8 Hz, the frequency of the fan was 25 Hz, and the grading efficiency was 200 Kg / h, and the particle size D50 of the obtained material was 13 μm.

[0099] (2) Product processing: the dispersed material was directly screened twice and de-magnetized twice by using an air flow screen with a particle size of 270 mesh, and thus a normal artificial graphite negative electrode material was obtained.

[0100] Comparative Example 2

[0101] According to the preparation steps (a)-(f) of the secondary oversize in Example 1 above, a secondary oversize was obtained, as shown in Figure 2. Figure 1 SEM image of the obtained secondary oversize is shown in Figure 2.

[0102] Comparative Example 3

[0103] First, the powder e was prepared according to steps (a)-(e) of the secondary oversize in Example 1 above, and then the carbonized powder e was screened twice and de-magnetized twice, and thus an artificial graphite negative electrode material without secondary oversize was obtained.

[0104] Effect Example 1: Morphology Characterization

[0105] Scanning electron microscope (SEM) was used for testing: instrument model: S-4800, Hitachi, Japan.

[0106] The morphology of the secondary oversize in Example 1 and Comparative Example 2 above was characterized by SEM.

[0107] Figure 1 Figure 3 is a 2000 times SEM image of the untreated secondary oversize of Comparative Example 2, Figure 2 Figure 4 is a 2000 times SEM image of the treated secondary oversize of Example 1. Figure 2 Example 1 compared with Figure 1 Comparative Example 2, the structure of the artificial graphite product obtained after processing the secondary oversize and the artificial graphite semi-product together became loose, and there were no whole large particles, and the uniformity and safety of the material were improved to a certain extent.

[0108] Effect Example 2

[0109] The artificial graphite negative electrode materials of the above embodiment 1 and comparative examples 1-3 are respectively subjected to electrochemical performance test, and the test results are listed in Table 1 below, wherein the discharge capacity is measured by using a blue electric test cabinet for charge-discharge test to obtain the discharge capacity of the negative electrode material, wherein the discharge radius is 10 mm, the thickness is 3.2 mm, and the discharge type is CR2032. The charge-discharge system is as follows: first, 0.05C constant current discharge to 5mV, stand for 10 min, then constant 0.1C current charging to 2.0V voltage, stand for 5 min. The tap density is measured by using a Zhuhai Euromex TD-03 type, 3000 times; the compacted density is measured by using a Ruikewei FT-100F powder automatic compacted density instrument, powder pressure is 5T; and the specific surface area is measured by using a Besside BSD-660S, default general automatic test parameters.

[0110] Table 1:

[0111]

[0112] Conclusion: Comparative example 1 is the secondary screen oversize obtained by only dispersing and grading, but without graphitization and carbonization treatment steps, comparative example 2 is the secondary screen oversize selected from a normal artificial graphite finished product, comparative example 3 is a normal artificial graphite finished product, and embodiment 1 is an artificial graphite finished product obtained by processing the secondary screen oversize and the artificial graphite semi-finished product together. It can be seen from the table that the performance of embodiment 1 is close to that of comparative example 3, which is a qualified artificial graphite negative electrode material, and although the particle size of comparative example 1 is close to that of the normal artificial graphite, there is still a significant gap in specific surface, tap density and powder pressure, so it cannot be used as a battery negative electrode material.

[0113] In summary, the secondary screen oversize treated by the method of the present application can obtain a qualified artificial graphite negative electrode material with performance meeting the requirements.

Claims

1. A method for processing a secondary oversize of artificial graphite, characterized by, It comprises the following steps: (1) The artificial graphite secondary oversize is subjected to dispersing treatment and grading treatment in sequence to obtain material A; (2) The material A is mixed with artificial graphite semi-finished product, and subjected to graphitization treatment to obtain material B; (3) The material B is mixed with modified pitch, and subjected to carbonization treatment to obtain material C; (4) The material C is subjected to finished product processing treatment to obtain the artificial graphite negative electrode material after treatment; The artificial graphite secondary oversize is prepared by the following method: (a) The artificial graphite raw material is subjected to crushing treatment to obtain powder a; (b) The powder a is subjected to shaping treatment to obtain powder b; (c) The powder b is mixed with pitch, and subjected to granulation treatment to obtain powder c; (d) The powder c is subjected to graphitization treatment to obtain powder d; (e) The powder d is mixed with modified pitch, and subjected to carbonization treatment to obtain powder e; (f) The powder e is subjected to finished product processing treatment to obtain the artificial graphite secondary oversize; The artificial graphite semi-finished product is prepared by the above steps (a)-(d); In step (4), the finished product processing treatment comprises the steps of screening and demagnetizing the material C; In step (f), the finished product processing treatment comprises the steps of screening and demagnetizing the powder e.

2. The method for processing artificial graphite oversize according to claim 1, characterized by, It satisfies one or more of the following conditions: (1) The artificial graphite raw material is one or more of pitch coke, petroleum coke and coal-based coke; (2) In step (1), the particle size D50 of the material A is 11.5-14.5 μm; (3) In step (2), the dosage of the artificial graphite semi-finished product is 10%-30% of the total mass of the material A and the artificial graphite semi-finished product; (4) In step (3), the dosage of the modified pitch is 10%-30% of the total mass of the material B and the modified pitch; (5) In step (3), the particle size of the modified pitch is 3-6 μm; (6) In step (3), the coking value of the modified pitch is not higher than 30%; (7) In step (3), the modified asphalt has a density of 1.05-1.1 g / cm3 at 30°C 3 .

3. The method of processing artificial graphite oversize according to claim 1, characterized in that, It satisfies one or more of the following conditions: (1) The artificial graphite raw material is petroleum coke; (2) In step (1), the particle size D50 of the material A is 13 μm; (3) In step (2), the dosage of the artificial graphite semi-finished product is 15% of the total mass of the material A and the artificial graphite semi-finished product; (4) In step (3), the dosage of the modified pitch is 15% of the total mass of the material B and the modified pitch; (5) In step (3), the particle size of the modified pitch is 4 μm; (6) In step (3), the coking value of the modified pitch is 30%; (7) In step (3), the modified asphalt has a density of 1.07 g / cm3 at 30°C 3 .

4. The method of processing artificial graphite oversize according to claim 1, characterized in that, It satisfies one or more of the following conditions: (1) In step (1), the dispersing treatment is performed in a dispersing machine; wherein the main machine frequency of the dispersing machine is 20-40 Hz; the rotating speed of the dispersing machine is 300-1200 r / min; the feeding frequency of the dispersing machine is 5-10 Hz; and the dispersing efficiency of the dispersing machine is 300-1500 Kg / h; (2) In step (1), the grading treatment is performed in a grading machine; wherein the feeding frequency of the grading machine is 3-10 Hz; the fan frequency of the grading machine is 20-50 Hz; and the grading efficiency of the grading machine is 150-500 Kg / h; (3) In step (2), the temperature of the graphitization treatment is 2800-3000℃; (4) In step (3), the temperature of the carbonization treatment is 1000-1200℃; (5) In step (3), the mixed material B is mixed with the modified asphalt until uniform.

5. The method of processing artificial graphite oversize according to claim 4, characterized in that, It meets one or more of the following conditions: (1) In step (1), the dispersing treatment is performed in a dispersing machine; wherein the main frequency of the dispersing machine is 30Hz; the rotating speed of the dispersing machine is 600r / min; the feeding frequency of the dispersing machine is 10Hz; the dispersing efficiency of the dispersing machine is 750Kg / h; (2) In step (1), the grading treatment is performed in a grading machine; wherein the feeding frequency of the grading machine is 8Hz; the fan frequency of the grading machine is 25Hz; the grading efficiency of the grading machine is 200Kg / h; (3) In step (2), the temperature of the graphitization treatment is 3000℃; (4) In step (3), the temperature of the carbonization treatment is 1200℃.

6. The method of processing artificial graphite oversize according to claim 4, characterized by, It meets one or more of the following conditions: (1) In step (3), the mixed material B is stirred with the modified asphalt at room temperature for 1h; (2) The screening is performed in a screening device, which is an air flow screen; wherein the particle size of the air flow screen is 270 mesh; (3) The screening is performed twice; (4) The demagnetization is performed in a demagnetizing machine; (5) The demagnetization is performed twice.

7. The method of processing artificial graphite oversize according to claim 1, characterized in that, It meets one or more of the following conditions: (1) In step (a), the particle size of the powder a is not greater than 100μm; (2) In step (b), the particle size of the powder b is 6-8μm; (3) In step (c), the amount of the asphalt is 18% of the total mass of the powder b and the asphalt; (4) In step (c), the particle size D50 of the asphalt is 3.3-5.5μm; (5) In step (c), the coking value of the asphalt is 60-75%.

8. The method of processing artificial graphite oversize according to claim 7, characterized in that, It meets one or more of the following conditions: (1) In step (c), the particle size D50 of the asphalt is 3.71μm; (2) In step (c), the coking value of the asphalt is 67%.

9. The method of processing artificial graphite secondary oversize according to claim 1, characterized by, It meets one or more of the following conditions: (1) In step (a), before the crushing treatment, the raw material is subjected to a crushing treatment by a crusher, wherein the particle size of the crushed raw material is not greater than 10mm; (2) In step (b), before the shaping treatment, the powder a is subjected to a grading treatment once; (3) In step (b), the shaping is performed twice; (4) In step (c), the granulation treatment is performed in a granulation device, which is a reaction kettle; (5) In step (d), the graphitization treatment is performed in a reaction container, which is a box furnace; (6) In step (d), the temperature of the graphitization treatment is 2800-3000℃.

10. The method of processing artificial graphite oversize according to claim 9, characterized in that, In step (d), the temperature of the graphitization treatment is 3000℃.

11. The method of processing artificial graphite oversize according to claim 9, characterized in that, It meets one or more of the following conditions: (1) The mixed powder d is stirred with the modified asphalt at room temperature for 1h; (2) the screening is performed in a screening device, and the screening device is an air current screen; wherein the particle size of the air current screen is 270 mesh; (3) the screening is performed twice; (4) the demagnetization is performed in a demagnetizer; (5) the demagnetization is performed twice.

12. The method of processing artificial graphite oversize according to claim 1, characterized in that, It meets one or more of the following conditions: (1) in step (e), the particle size of the modified asphalt is 3-6 μm; (2) in step (e), the coking value of the modified asphalt is not higher than 30%; (3) In step (e), the modified asphalt has a density of 1.05 to 1.1 g / cm3 at 30°C 3 ; (4) in step (e), the amount of the modified asphalt is 10%-30% of the total mass of the powder d and the modified asphalt; (5) in step (e), the carbonization treatment is performed in a reaction container, and the reaction container is a kiln; (6) in step (e), the temperature of the carbonization treatment is 1000-1200℃; (7) in step (e), the powder d and the modified asphalt are mixed until uniform.

13. The method of processing artificial graphite secondary oversize of claim 1, wherein It meets one or more of the following conditions: (1) in step (e), the particle size of the modified asphalt is 4 μm; (2) in step (e), the coking value of the modified asphalt is 30%; (3) In step (e), the modified asphalt has a density of 1.07 g / cm3at 30°C 3 ; (4) in step (e), the amount of the modified asphalt is 15% of the total mass of the powder d and the modified asphalt; (5) in step (e), the temperature of the carbonization treatment is 1200℃.

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