Graphene based on industrial waste and manufacturing method of modified material of graphene

Abstract

The invention relates to a preparation method of graphene based on industrial waste and a modified material thereof, and the preparation method comprises the following steps: S1, treating a recycled waste graphite electrode to obtain regenerated graphite; s2, weighing regenerated graphite, adding concentrated sulfuric acid, and stirring, so that the regenerated graphite and the concentrated sulfuric acid are fully and uniformly mixed; s3, slowly adding hydrogen peroxide into the mixed solution of the regenerated graphite and the concentrated sulfuric acid, fully stirring, controlling the temperature of a reaction system, and standing for spontaneous intercalation; s4, filtering and washing to be neutral by using ultrapure water; s5, drying to obtain expandable graphite, and treating the expandable graphite to obtain expanded graphite; s6, performing intercalation oxidation treatment on the expanded graphite; and S7, treating the product in the step S6 to obtain graphene.

Description

Technical Field

[0001] The present application relates to the field of material manufacturing, and in particular to a method for manufacturing graphene and modified materials thereof based on industrial waste. Background Art

[0002] Graphite electrode is an important conductive material in modern industry and is widely used in electric furnace steelmaking, electrolysis, electroplating and other fields.

[0003] With the acceleration of the global industrialization process, the demand for high-performance materials in various industries continues to increase, especially in high-tech industries such as electronics, automobiles, energy, and aviation. The special properties of graphite make it have important application potential in these fields. Graphite materials can be used to manufacture efficient heat exchangers, heat dissipation systems for electronic components, electrode materials for batteries, thermal conductive sheets, anti-corrosion components, etc. In the fields of new energy vehicles, battery technology, etc., the high conductivity, high stability and high temperature resistance of special graphite make it an important material choice.

[0004] However, as a carbon material, graphite has limited resource reserves, and the mining of natural graphite has a certain destructive effect on the ecological environment. With the intensification of global resource shortage problems, the recycling and reuse of discarded graphite electrodes has a significant resource-saving effect. In addition, discarded graphite electrodes contain a large amount of harmful substances, and direct disposal will cause pollution to water sources, soil and air. Therefore, the recycling of graphite electrodes is not only a need for resource conservation, but also an important measure for environmental protection. In addition, graphite electrodes will produce waste due to oxidation, burning and other reasons during use. Especially in the process of electric furnace steelmaking, due to the high temperature, the consumption of graphite electrodes is large, and the volume and weight of discarded electrodes are also considerable. If these discarded graphite electrodes are not properly disposed of, they will not only take up a lot of space, but also may pollute the environment. At the same time, the price of graphite electrodes is high, the energy consumption in its manufacturing process is huge, and the requirements for raw materials are relatively harsh. At the same time, with the popularization of electric furnace steelmaking technology, the demand for graphite electrodes has shown a rapid growth trend, the demand for raw materials has also increased, and the mining of raw materials will also cause a burden on the environment. Summary of the invention

[0005] The present application provides a method for manufacturing graphene and modified materials thereof based on industrial waste to solve the problem of recycling and reuse of waste graphite products.

[0006] In a first aspect, the present application provides a graphene manufacturing process based on industrial waste, comprising the steps of: S1, processing the recycled waste graphite electrodes to obtain regenerated graphite; S2, weighing the regenerated graphite, adding concentrated sulfuric acid and stirring, so that the regenerated graphite and the concentrated sulfuric acid are fully mixed; S3, taking hydrogen peroxide, slowly adding it into the mixed solution of regenerated graphite and concentrated sulfuric acid, and fully stirring, controlling the temperature of the reaction system, and standing it to allow spontaneous intercalation; S4, filtering and washing with ultrapure water until neutral; S5, drying to obtain expandable graphite, and treating the expandable graphite to obtain expanded graphite; S6, intercalation oxidation treatment of expanded graphite; S7, processing the product of step S6 to obtain graphene.

[0007] Preferably, in step S2, the stirring method is magnetic stirring, and the stirring time is not less than 2 minutes.

[0008] Preferably, in step S3, the mass fraction of hydrogen peroxide is 30%, the temperature of the reaction system is controlled below 80° C., and after the addition of hydrogen peroxide is completed, stirring is continued for 8-15 minutes.

[0009] Preferably, in step S3, the mixture is allowed to stand at room temperature for no less than 24 hours.

[0010] Preferably, in step S5, the drying process is to place the filtrate in a constant temperature oven at 60° C. for drying, and the process of treating the expandable graphite is to place the expandable graphite at 850° C. for reaction to obtain the expandable graphite.

[0011] Preferably, in step S6, the process of performing oxidation treatment on the expanded graphite includes: S61, adding concentrated sulfuric acid to the expanded graphite in an ice-water bath, and then adding potassium permanganate in small batches, and maintaining the ice-water bath environment during the process, at which time the mixed solution is dark purple; S62, continued the reaction at room temperature for 3 h, diluted with deionized water for hydrolysis reaction, and maintained for 6 h to obtain an oxidized expanded graphite compound with a multilayer GO (graphene oxide) structure; S63, continue to dilute the mixed solution with deionized water and add hydrogen peroxide to remove excess potassium permanganate after the reaction, the mixed solution changes from orange-yellow to bright yellow, the bright yellow mixed solution is allowed to stand for stratification, the supernatant is poured out, and the mixed solution is repeatedly allowed to stand for washing, and finally the mixed solution is centrifuged in a centrifuge, and the mixed solution is repeatedly allowed to stand for washing for multiple times until no white precipitate is generated when the BaCl2 solution is added to the supernatant; S64, collecting the solid on the centrifuge and freeze-drying it for storage to obtain the expanded graphene treated with intercalation oxidation.

[0012] In step S7 of this embodiment, the process of processing the product of step S6 to obtain graphene includes: S7a, preparing graphene by a reduction method; or, S7b, graphene prepared by ultrasonic exfoliation.

[0013] The present invention also provides a process for manufacturing graphene-modified fine-structure graphite, comprising the steps of: S80, preparing graphene by any of the above graphene manufacturing processes; S81, mixing graphene with coal tar pitch to prepare an impregnation modifier; S82, impregnating and curing the fine structure graphite by impregnating a modifier; S83, high temperature carbonization treatment; S84, graphitization treatment; S85, repeat steps S82, S83 and S84 multiple times to obtain graphene-modified fine-structure graphite.

[0014] The present invention also provides a process for manufacturing a graphene-modified carbon-carbon composite material, comprising the steps of: S90, preparing graphene by any of the above graphene manufacturing processes; S91, mixing graphene with coal tar pitch to prepare an impregnation modifier; S92, impregnating and curing the carbon-carbon composite material by impregnating a modifier; S93, performing isothermal static pressing treatment; S94, high temperature carbonization treatment; S95, graphitization treatment; S96, repeat steps S92, S93, S94 and S95 multiple times to obtain a graphene-modified carbon-carbon composite material.

[0015] The present invention also provides a process for manufacturing a carbon-ceramic composite material, comprising the steps of: S100, preparing a graphene-modified carbon-carbon composite material by the above-mentioned graphene-modified carbon-carbon composite material manufacturing process; S101, ball-milling and mixing silicon powder, carbon powder and alumina to obtain ceramic coating powder; S102, embedding the graphene-modified carbon-carbon composite material with a ceramic coating powder; S103, performing high temperature calcination; S104, obtaining a carbon-ceramic composite material.

[0016] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: The method provided in the embodiment of the present application prepares regenerated graphite by recycling waste graphite electrodes, and prepares expanded graphite and graphene by the regenerated graphite, which has better thermal conductivity. A variety of thermally conductive graphite-based materials can be processed based on the graphene to better exert the thermal conductivity advantage of graphite. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0020] Figure 1 Flow chart of the method for manufacturing graphene based on industrial waste provided in the embodiment of the present application Figure 2 A flow chart of a method for processing waste graphite electrodes to obtain regenerated graphite provided in an embodiment of the present application; Figure 3A is the Raman spectrum of waste graphite; Figure 3B Raman spectrum of regenerated graphite; Figure 4A is the SEM image of graphite slag; Figure 4B This is the SEM image of the regenerated graphite; Figure 5A This is the SEM image of the regenerated graphite before expansion; Figure 5B This is the SEM image of the regenerated graphite after expansion; Figure 6 XRD diagram of expanded graphite before and after intercalation oxidation treatment; Fig. 7A This is a scanning electron microscope image of expanded graphite before intercalation oxidation treatment; Figure 7B This is a scanning electron microscope image of expanded graphite after intercalation oxidation treatment; Figure 8 A process flow chart for manufacturing fine-structure graphite modified with graphene; Fig. 9 A manufacturing process flow chart of graphene-modified carbon-carbon composite materials; Fig.10 This is a manufacturing process flow chart of carbon-ceramic composite materials. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0022] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0023] For ease of description, spatial relative terms may be used herein to describe the relative positional relationship or movement of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", "front", "back", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or a posture change or a motion state change, then these directional indications also change accordingly, for example: an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative descriptors used herein are interpreted accordingly.

[0024] In order to solve the technical problem of recycling waste graphite electrodes in the prior art, the present application provides a method for obtaining graphite raw materials based on industrial waste, which can convert waste graphite electrodes into recycled graphite, which can be used to produce graphene materials.

[0025] Figure 1A method for producing graphene based on industrial waste provided in an embodiment of the present application comprises the steps of: S1, processing the recycled waste graphite electrodes to obtain regenerated graphite; S2, weighing the regenerated graphite, adding concentrated sulfuric acid and stirring, so that the regenerated graphite and the concentrated sulfuric acid are fully mixed; S3, taking hydrogen peroxide, slowly adding it into the mixed solution of regenerated graphite and concentrated sulfuric acid, and fully stirring, controlling the temperature of the reaction system, and standing it to allow spontaneous intercalation; S4, filtering and washing with ultrapure water until neutral; S5, drying to obtain expandable graphite, and treating the expandable graphite to obtain expanded graphite; S6, intercalation oxidation treatment of expanded graphite; S7, processing the product of step S6 to obtain graphene.

[0026] like Figure 2 As shown, in step S1, processing the waste graphite electrode to obtain regenerated graphite specifically includes the following steps: S11, crushing the recycled waste graphite electrodes to obtain graphite slag; S12, treating the graphite slag with acid and soaking it for a first preset time; S13, washing the immersed graphite slag mixed solution with water until it becomes neutral; S14, drying to obtain acid-treated graphite slag; S15, weighing the acid-treated graphite slag, adding 2M HCl solution, and stirring in an ice bath until the graphite slag no longer floats on the surface; S16, adding the first coating agent, continuing stirring until the system temperature is lower than 10° C., then adding the second coating agent, and waiting for the reaction for a second preset time; S17, after the reaction is completed, filtering, washing and drying are performed to obtain coated graphite; S18, graphitizing the coated graphite to obtain regenerated graphite.

[0027] In step S11 of this embodiment, waste graphite electrodes are an important resource, and recycling can reduce resource waste and environmental pollution. The recycled waste graphite electrodes need to be crushed before preparing regenerated graphite to obtain graphite slag for further processing. After recycling, the waste graphite electrodes can be mechanically crushed into small particles (i.e., graphite slag) by a grinder to facilitate subsequent processing.

[0028] In step S12 of this embodiment, the acid treatment is to mix and stir the graphite slag with 2M H2SO4 acid solution in a ratio of 1:1-10. The acid treatment process is to oxidize the graphite to facilitate the subsequent treatment steps.

[0029] Furthermore, in step S12, the first preset soaking time is 17-24 hours, and the purpose of soaking is to fully oxidize the graphite.

[0030] In step S13 of the present embodiment, the immersed graphite slag mixed solution is washed by adding deionized water and a dilute acid solution for alternate washing until the pH value is close to neutral.

[0031] In step S14 of this embodiment, the drying process is performed by drying the mixed solution under high temperature conditions, for example, continuously drying at 50-120° C. for 24-72 hours until the water is evaporated to obtain acid-treated graphite slag.

[0032] In step S15 of the present embodiment, 5-7 ml of 2M HCl solution is added to every 5 g of acid-treated graphite slag, and the mixture is stirred in an ice bath until the graphite no longer floats on the surface, wherein 2M HCl is used as a reducing agent to react with the acid-treated graphite slag, and the temperature is low under the ice bath condition, which can prevent the reduced graphite from being oxidized again.

[0033] In step S16 of this embodiment, 0.4-0.6 ml of the first coating agent is added to every 5 g of acid-treated graphite slag. The first coating agent is epoxy resin. Of course, the first coating agent liquid can be made of other resin materials, such as polyurethane, acrylic acid, two-component silicone rubber and the like.

[0034] In step S16 of this embodiment, 0.5-1.2 ml of a second coating agent is added to every 5 g of acid-treated graphite slag, and the second coating agent is a modified amine curing agent.

[0035] Specifically, the second coating agent is added in a continuous dripping manner so that the second coating agent can be fully mixed with the graphite to coat the graphite.

[0036] In step S16 of this embodiment, the second preset time for reaction after adding the second coating agent is 16-20 hours to allow for sufficient reaction.

[0037] In step S17 of the present embodiment, the filtering method is suction filtration, which can improve the filtering efficiency.

[0038] In step S18 of the present embodiment, graphitization of the coated graphite is achieved by heating. Of course, graphitization can also be achieved by other methods, such as ball milling, chemical reduction, etc.

[0039] Based on the above treatment method, a large amount of metal elements in graphite slag can be removed, and the metal element content of the obtained recycled graphite is greatly reduced, which can be used as a raw material for the production of graphene and its related products. Specifically, through the analysis of trace metal elements in graphite slag and recycled graphite, the metal element content of the two is shown in the following table: Table 1 Content of trace metal elements in graphite slag and recycled graphite like Figure 3A and Figure 3B The Raman spectra of waste graphite and regenerated graphite are shown in Figure 1. Through Raman spectroscopy analysis, the spectra show two peaks centered at around 1360 and 1580 cm-1, which correspond to the disorder-induced Raman mode (D peak) and the in-plane optical vibration Raman mode (G peak) in the carbon material, respectively. The D peak characterizes the structural defects in the carbon material. The ratio of the D peak intensity to the G peak intensity (ID / IG) is usually used to measure the degree of graphitization. The higher the ID / IG value, the more structural defects there are and the lower the degree of graphitization. As can be seen from the figure, compared with the ID / IG value of 0.21 for waste graphite, the ID / IG value of the regenerated and repaired PCR graphite is 0.14, indicating that the degree of defects in the material is significantly reduced after the waste graphite is regenerated and repaired.

[0040] like Figure 4A and Figure 4B Shown are SEM images (scanning electron microscope) of graphite slag and regenerated graphite. From the image, it can be seen that the particle size of the sample is significantly increased after the graphite slag is repaired and regenerated.

[0041] From the above analysis, it can be seen that the degree of material defects in the recycled graphite has been significantly reduced, and the conditions are now suitable for the preparation of graphene.

[0042] In step S2 of this embodiment, the stirring method is magnetic stirring, and the stirring time is not less than 2 minutes.

[0043] In step S3 of this embodiment, the mass fraction of hydrogen peroxide is 30%, the temperature of the reaction system is controlled below 80° C. After the addition of hydrogen peroxide is completed, stirring is continued for 8-15 minutes. In this embodiment, stirring is continued for 10 minutes.

[0044] Furthermore, in step S3, after the stirring is completed, the mixture is allowed to stand at room temperature for no less than 24 hours.

[0045] In step S4 of this embodiment, the reaction product of step S3 is poured into a filtering device, ultrapure water is added for filtering and washing, and the product is tested by pH test paper until it is washed to neutral.

[0046] In step S5 of this embodiment, the drying process is to place the filtrate in a constant temperature oven at 60° C. for drying, and the process of treating the expandable graphite is to place the expandable graphite at 850° C. for reaction to obtain the expandable graphite.

[0047] like Figure 5A and Figure 5B The figure shows the SEM images of the regenerated graphite before and after expansion. The expanded graphite was analyzed by scanning electron microscopy. It can be seen that the particle size of the sample is significantly increased after the graphite is repaired and regenerated, and the morphology has changed significantly. The original graphite is a stacked structure of sheets, while the expanded graphite is worm-like.

[0048] In step S6 of this embodiment, the process of performing oxidation treatment on expanded graphite includes: S61, adding concentrated sulfuric acid to the expanded graphite in an ice-water bath, adding 1g of expanded graphite to 200ml of concentrated sulfuric acid, and then adding potassium permanganate in small batches, adding 1g of expanded graphite to 3g of potassium permanganate, and continuously maintaining an ice-water bath environment during the process, at this time, the mixed solution is dark purple; S62, the reaction was continued at room temperature for 3 h, and then the hydrolysis reaction was carried out by diluting with deionized water. Based on the ratio of 1g expanded graphite to 200ml concentrated sulfuric acid, the mixture was easily diluted to about 500ml by deionized water, and the hydrolysis reaction was maintained for 6 h, thus obtaining an oxidized expanded graphite compound with a multilayer GO (graphene oxide) structure.

[0049] S63, continue to dilute the mixed solution with deionized water and add hydrogen peroxide to remove excess potassium permanganate after the reaction, based on the ratio of 1g expanded graphite to 200ml concentrated sulfuric acid, the mixture is easily diluted to about 500ml by deionized water, and continue to dilute to about 1250ml, add 25ml hydrogen peroxide, until the mixed solution changes from orange-yellow to bright yellow, then let the bright yellow mixed solution stand for stratification, pour out the supernatant, repeatedly stand for washing for multiple times, 5 times in this embodiment, finally put the mixed solution into a centrifuge with a rotation speed of 8500rpm, repeatedly stand for washing for multiple times, until BaCl2 solution is added dropwise to the supernatant without generating a white precipitate; S64, collecting the solid on the centrifuge and freeze-drying it for storage to obtain the expanded graphene treated with intercalation oxidation.

[0050] like Figure 6The XRD graph of expanded graphite before and after intercalation oxidation treatment is shown. It can be seen from the figure that expanded graphite shows a very strong characteristic peak at around 26°, which corresponds to the (002) plane of graphite carbon; after the expanded graphite is intercalated and oxidized, the (002) of graphite carbon moves to a low diffraction angle, and graphene oxide shows a strong characteristic peak at around 9.5°. This result shows that the interlayer spacing of expanded graphite increases significantly before and after intercalation oxidation treatment.

[0051] like Fig. 7A and Figure 7B The following is a scanning electron microscope image of expanded graphite before and after intercalation oxidation treatment. It can be seen from the figure that the morphology and particle size of expanded graphite have changed significantly after intercalation oxidation treatment. Expanded graphite is worm-like and has a large particle size, but after intercalation oxidation treatment, the particle size becomes smaller and has a wrinkled sheet stacking structure.

[0052] Furthermore, in step S7 of this embodiment, the process of processing by the reduction method includes: S7a, preparing graphene by a reduction method; or, S7b, graphene prepared by ultrasonic exfoliation.

[0053] Wherein, step S7a specifically comprises: obtaining GO powder according to the above method, adding it to deionized water for dispersion for 2 h under ultrasonic ice bath to prepare GO dispersion liquid, and the concentration of the ratio liquid is 3 mg / mL. Add ascorbic acid (L-AA) powder to the GO dispersion liquid, so that L-AA:GO=10:1, ultrasonically disperse it under ice bath for 1 h, and stand it at room temperature for 48 h to allow the reduction reaction to proceed completely. Rinse the reaction liquid with deionized water to neutrality, and the prepared reaction liquid is vacuum-freeze-dried for 48 h to obtain a dark brown flocculent powder, i.e., high-purity, high-thermal-conductivity graphene.

[0054] Wherein, step S7b specifically includes: dispersing expanded graphite into a dispersion liquid, peeling off layer by layer through ultrasonic oscillation, and finally obtaining graphene with high purity and high thermal conductivity.

[0055] The graphene obtained based on the above process can be used to prepare related modified materials, such as graphene-modified fine-structure graphite, graphene-modified carbon-carbon composite materials, and carbon-ceramic composite materials.

[0056] like Figure 8 The present invention provides a method for manufacturing graphene-modified fine-structure graphite, which includes the following steps: S80, preparing graphene by any of the above graphene manufacturing processes; S81, mixing graphene with coal tar pitch to prepare an impregnation modifier; S82, impregnating and curing the fine structure graphite by impregnating a modifier; S83, high temperature carbonization treatment; S84, graphitization treatment; S85, repeat steps S82, S83 and S84 multiple times to obtain graphene-modified fine-structure graphite.

[0057] In this embodiment, the impregnation modifier is prepared by mixing graphene with coal tar, and the fine-structured graphite is impregnated, solidified and graphitized multiple times, thereby improving the density and strength of the fine-structured graphite and preparing a fine-structured graphite material with higher performance.

[0058] like Fig. 9 The present invention provides a method for manufacturing a graphene-modified carbon-carbon composite material, including the following steps: S90, preparing graphene by any of the above graphene manufacturing processes; S91, mixing graphene with coal tar pitch to prepare an impregnation modifier; S92, impregnating and curing the carbon-carbon composite material by impregnating a modifier; S93, performing isothermal static pressing treatment; S94, high temperature carbonization treatment; S95, graphitization treatment; S96, repeat steps S92, S93, S94 and S95 multiple times to obtain a graphene-modified carbon-carbon composite material.

[0059] In this embodiment, the impregnation modifier is prepared by using mixed coal tar pitch, and the fine structure graphite is impregnated, solidified and graphitized multiple times to further improve the density and strength of the carbon-carbon composite material, thereby preparing a higher performance carbon / carbon composite material. like Fig.10 The present invention provides a method for manufacturing a carbon-ceramic composite material, which includes the following steps: S100, preparing a graphene-modified carbon-carbon composite material by the above-mentioned graphene-modified carbon-carbon composite material manufacturing process; S101, ball-milling and mixing silicon powder, carbon powder and alumina to obtain ceramic coating powder; S102, embedding the graphene-modified carbon-carbon composite material with a ceramic coating powder; S103, performing high temperature calcination; S104, obtaining a carbon-ceramic composite material.

[0060] In this embodiment, a layer of ceramic material is coated on the surface of the carbon-carbon composite material to form a carbon-ceramic composite material. This composite material combines the advantages of carbon / carbon composite materials and ceramic materials, has higher oxidation resistance, high temperature resistance and mechanical strength, and is suitable for harsh environments such as high temperature, friction and corrosion.

[0061] It should be understood that the terms used in the text are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used in the text may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described in the text are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0062] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0063] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A graphene manufacturing process based on industrial waste, characterized in that: Includes steps: S1, processing the recycled waste graphite electrodes to obtain regenerated graphite; S2, weighing the regenerated graphite, adding concentrated sulfuric acid and stirring, so that the regenerated graphite and the concentrated sulfuric acid are fully mixed; S3, taking hydrogen peroxide, slowly adding it into the mixed solution of regenerated graphite and concentrated sulfuric acid, and fully stirring, controlling the temperature of the reaction system, and standing it to allow spontaneous intercalation; S4, filtering and washing with ultrapure water until neutral; S5, drying to obtain expandable graphite, and treating the expandable graphite to obtain expanded graphite; S6, intercalation oxidation treatment of expanded graphite; S7, processing the product of step S6 to obtain graphene.

2. The manufacturing process according to claim 1, characterized in that: In step S2, the stirring method is magnetic stirring, and the stirring time is not less than 2 minutes.

3. The manufacturing process according to claim 1, characterized in that: In step S3, the mass fraction of hydrogen peroxide is 30%, the temperature of the reaction system is controlled below 80° C., and after the addition of hydrogen peroxide is completed, stirring is continued for 8-15 minutes.

4. The manufacturing process according to claim 3, characterized in that: In the step S3, the mixture is allowed to stand at room temperature for no less than 24 hours.

5. The manufacturing process according to claim 1, characterized in that: In step S5, the drying process is to place the filtered material in a constant temperature oven at 60° C. for drying, and the process of treating the expandable graphite is to place the expandable graphite at 850° C. for reaction to obtain the expandable graphite.

6. The manufacturing process according to claim 1, characterized in that: In step S6, the process of performing oxidation treatment on expanded graphite includes: S61, adding concentrated sulfuric acid to the expanded graphite in an ice-water bath, and then adding potassium permanganate in small batches, and maintaining the ice-water bath environment during the process, at which time the mixed solution is dark purple; S62, continued the reaction at room temperature for 3 h, diluted with deionized water for hydrolysis reaction, and maintained for 6 h to obtain an oxidized expanded graphite compound with a multilayer GO structure; S63, continue to dilute the mixed solution with deionized water and add hydrogen peroxide to remove excess potassium permanganate after the reaction, the mixed solution changes from orange-yellow to bright yellow, the bright yellow mixed solution is allowed to stand for stratification, the supernatant is poured out, and the mixed solution is repeatedly allowed to stand for washing, and finally the mixed solution is centrifuged in a centrifuge, and the mixed solution is repeatedly allowed to stand for washing for multiple times until no white precipitate is generated when the BaCl2 solution is added to the supernatant; S64, collecting the solid on the centrifuge and freeze-drying it for storage to obtain the expanded graphene treated with intercalation oxidation.

7. The manufacturing process according to claim 1, characterized in that: In step S7, the process of processing the product of step S6 to obtain graphene includes: S7a, preparing graphene by a reduction method; or, S7b, graphene prepared by ultrasonic exfoliation.

8. A process for manufacturing graphene-modified fine-structure graphite, characterized in that: Includes steps: S80, preparing graphene by the manufacturing process according to any one of claims 1 to 7; S81, mixing graphene with coal tar pitch to prepare an impregnation modifier; S82, impregnating and curing the fine structure graphite by impregnating a modifier; S83, high temperature carbonization treatment; S84, graphitization treatment; S85, repeat steps S82, S83 and S84 multiple times to obtain graphene-modified fine-structure graphite.

9. A process for manufacturing a graphene-modified carbon-carbon composite material, characterized in that: Includes steps: S90, preparing graphene by the manufacturing process according to any one of claims 1 to 7; S91, mixing graphene with coal tar pitch to prepare an impregnation modifier; S92, impregnating and curing the carbon-carbon composite material by impregnating a modifier; S93, performing isothermal static pressing treatment; S94, high temperature carbonization treatment; S95, graphitization treatment; S96, repeat steps S92, S93, S94 and S95 multiple times to obtain a graphene-modified carbon-carbon composite material.

10. A process for manufacturing a carbon-ceramic composite material, characterized in that: Includes steps: S100, preparing a graphene-modified carbon-carbon composite material by the manufacturing process according to claim 9; S101, ball-milling and mixing silicon powder, carbon powder and alumina to obtain ceramic coating powder; S102, embedding the graphene-modified carbon-carbon composite material with a ceramic coating powder; S103, performing high temperature calcination; S104, obtaining a carbon-ceramic composite material.

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