Method for preparing graphene from graphite product or graphite mineral based on high-speed gas unloading and gas pushing

Abstract

The embodiment of the invention provides a method for preparing graphene from graphite products or graphite minerals based on high-speed gas unloading and gas pushing, and relates to the field of graphene preparation. The preparation method is low in cost, high in efficiency and suitable for large-scale production. Comprising the following steps: placing graphite products or graphite minerals in a high-pressure stock bin, and connecting and sealing one end of the high-pressure stock bin through an unloading device; the high-pressure stock bin is communicated with the interior of the unloading device; filling the high-pressure stock bin with gas with preset pressure, wherein the gas is carbon dioxide, nitrogen or air; the unloading device and the high-pressure stock bin part structure adjacent to the unloading device are arranged in a collecting bin; the unloading device is started, an outlet of the unloading device is opened, high-pressure gas in the stock bin is instantly released from the outlet, in the gas release process, the graphite products or the graphite minerals are sprayed out along with the high-pressure gas, the external gas pressure of the graphite products or the graphite minerals is rapidly reduced, and high pressure is still kept in the graphite minerals. Under the action of internal and external pressure difference, graphite or graphite minerals are crushed into powder, the powder enters the collecting bin from the outlet, and graphene can be extracted from the powder.

Description

Technical Field

[0001] The invention relates to the field of graphene preparation, and in particular to a method for preparing graphene from graphite products or graphite minerals based on gas high-speed unloading and gas promotion. Background Art

[0002] Graphene has been widely studied due to its unique physical and chemical properties. At present, the main methods for preparing graphene are as follows: For example, the mechanical exfoliation method, which is the earliest method for preparing graphene, uses mechanical force to peel off the graphene in graphite. This method is simple, but difficult to mass produce and is only suitable for laboratory research. Another method, chemical vapor deposition, is the most commonly used method in industry. Its principle is to decompose carbon-containing gases such as methane and acetylene at high temperature and form graphene films on the surface of metal catalysts such as copper and nickel. The advantage of this method is that large-area, continuous, single-layer or few-layer graphene can be prepared. However, it will have an impact on the environment. Another method is the redox method, which is to oxidize graphite by oxidizing graphite, and then reduce it to graphene by chemical reduction or thermal reduction. The advantage of this method is that the preparation process is relatively simple, but the quality of the obtained graphene is low and often contains more defects and impurities. The fourth is the outer edge growth method, which is to decompose the carbon source at high temperature to reorganize the carbon atoms on the surface to form a graphene layer. This method can produce high-quality graphene, but it is expensive because it requires high temperatures and specific substrates.

[0003] In summary, the methods of preparing graphene by the above methods are costly due to various reasons, and large-scale production is difficult, which also makes the price of graphene remain high. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a method for preparing graphene from graphite products or graphite minerals based on gas high-speed unloading and gas-propelled graphite products, which has low preparation cost, high efficiency, and is easily suitable for large-scale production.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme: A method for preparing graphene from graphite products or graphite minerals based on high-speed gas unloading and gas-propelled graphite products, comprising the steps of: placing the graphite products or graphite minerals in a high-pressure silo, and connecting and sealing one end of the high-pressure silo through an unloading device; the high-pressure silo is in communication with the interior of the unloading device; Filling the high-pressure silo with a gas of a predetermined pressure, wherein the gas is carbon dioxide, nitrogen or air; Placing the unloading device and the high-pressure silo structure connected to the unloading device in the collecting silo; The unloading device is started, and the outlet of the unloading device is opened, and the high-pressure gas in the silo is instantly released from the outlet. The graphite products or graphite minerals are ejected with the high-pressure gas flow, and the external gas pressure drops rapidly, while the internal pressure of the graphite minerals remains high. Under the action of the internal and external pressure difference, the graphite or graphite mineral is crushed into graphite or graphite mineral powder, which enters the collection bin from the outlet, and the graphite powder containing graphene is obtained.

[0006] Optionally, the other end of the high-pressure silo is connected to a pushing silo via a hose, and the pushing silo is connected to an external boosting device to increase the gas pressure in the pushing silo and the high-pressure silo connected to the interior thereof.

[0007] Optionally, the predetermined pressure is 10 MPa ~50 MPa.

[0008] Optionally, the connection between the high-pressure silo and the unloading device is a snap connection or a threaded connection.

[0009] Optionally, the unloading device includes a cavity, one end of which is a closed end and the other end is an opening, the open end is connected to the high-pressure silo, and a mechanical valve or a part with a pressure control function is provided on the surface of the cavity.

[0010] Optionally, a pushing device is provided in the high-pressure silo to push the material inside the high-pressure silo to quickly spray out of the high-pressure silo during the unloading process of the high-pressure silo.

[0011] When there is no external force, the pushing device is located near the other end of the high-pressure silo connected to the pushing silo. Under the push of the gas pressure in the pushing silo, the pushing device moves in the high-pressure silo to push the material inside the high-pressure silo to quickly spray out of the high-pressure silo.

[0012] Optionally, the high-pressure silo and the push silo can be made of resin, fiberglass, steel or aluminum alloy.

[0013] Optionally, the boosting device for increasing the pressure of the push bin and the high-pressure bin includes: a gas boosting pump or an air compressor.

[0014] Optionally, the collecting bin is in the shape of a cylinder, cone, cube or rectangular cylindrical structure, and is made of steel and aluminum alloy.

[0015] Optionally, a flange is installed on the outer side wall of the high-pressure silo, and one end of the collecting bin is connected to the flange and fixed with bolts to enclose part of the structure of the high-pressure silo.

[0016] The method for preparing graphene from graphite products or graphite minerals based on high-speed gas unloading and gas-propelled graphite products provided in the embodiment of the present invention is to place the graphite products or graphite minerals in a high-pressure silo, and to instantly release the high-pressure gas flow generated by unloading by utilizing the high-pressure gas in the sealed high-pressure silo, so that the graphite products or graphite minerals in the high-pressure silo are ejected together with the gas, and the gas pressure outside the graphite products or graphite minerals drops rapidly, while the inside of the graphite minerals still maintains high pressure, and under the action of the internal and external pressure difference, the graphite minerals expand and pulverize to obtain graphene. Thus, an efficient and simple physical method for preparing graphene is provided, which has low preparation cost and is easily suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic flow chart of an embodiment of a method for preparing graphene from graphite products or graphite minerals based on gas high-speed unloading and gas-propelled according to the present invention; Figure 2 It is a schematic structural diagram of an embodiment of an apparatus used for preparing graphene from graphite products or graphite minerals based on gas high-speed unloading and gas-propelled according to the present invention; Figure 3 The present invention is a diagram of the organizational structure of graphene under a microscope obtained by the method for preparing graphene from graphite products or graphite minerals based on gas high-speed unloading and gas propulsion. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0020] It should be clear that in order to more clearly illustrate the present invention, many technical details are described in the following specific embodiments. Those skilled in the art should understand that the present invention can also be implemented without some of the details. In addition, in order to highlight the main purpose of the present invention, some methods, means, parts and their applications well known to those skilled in the art are not described in detail, but this does not affect the implementation of the present invention. The embodiments described herein are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0021] Please see Figure 1 and Figure 2As shown, an embodiment of the present invention provides a method for preparing graphene from a graphite product or graphite mineral based on gas high-speed unloading and gas-propelled, which is applicable to graphene preparation scenarios, and includes the steps of: S110, placing raw materials 0 such as graphite products or graphite minerals in a high-pressure silo 1, and connecting and closing one end of the high-pressure silo 1 through an unloading device 2. The high-pressure silo 1 can be made of high-pressure resistant materials, such as high-strength resin, glass fiber, steel or aluminum alloy, to ensure stable operation under high-pressure environment.

[0022] S120, filling a gas of a predetermined pressure, such as carbon dioxide, nitrogen or air, into the high-pressure silo 1. The predetermined pressure is usually in the range of 10 MPa to 50 MPa to ensure that there is sufficient gas pressure to crush the graphite products or graphite mineral raw materials when unloading.

[0023] S130, placing the unloading device 2 and a part of the high-pressure silo 1 structure adjacent to the unloading device 2 in the collecting bin 3.

[0024] The order of step S120 and step S130 may be interchanged.

[0025] S140, start the unloading device 2, open the outlet 21 of the unloading device 2, and instantly release the high-pressure gas in the silo from the outlet 21. The gas pressure outside the graphite product or graphite mineral drops rapidly, while the inside of the graphite mineral still maintains high pressure. Under the action of the internal and external pressure difference, the graphite product or graphite mineral is crushed into graphite product or graphite mineral powder by the high-pressure gas, and enters the collecting bin 3 from the outlet 21, so as to obtain graphite powder containing graphene.

[0026] Of course, in order to improve the purity of graphene, it is also possible to extract a single layer of graphene after taking it out from the collection chamber 3 through a subsequent processing process.

[0027] The method for preparing graphene from graphite products or graphite minerals based on high-speed gas unloading and gas-propelled graphite products provided in the embodiment of the present invention is to place the graphite products or graphite minerals in a high-pressure silo 1, and to release the high-pressure gas generated by unloading instantly by utilizing the high-pressure gas in the sealed high-pressure silo 1. The graphite products or graphite minerals in the high-pressure silo 1 are ejected together with the gas, and the gas pressure outside the graphite products or graphite minerals drops rapidly, while the inside of the graphite minerals still maintains high pressure. Under the action of the internal and external pressure difference, the graphite minerals expand and pulverize to obtain graphene. This provides an efficient and simple physical method for preparing graphene, which has low preparation cost and is easily suitable for large-scale production.

[0028] Therefore, in the embodiments of the present invention, the graphite products or graphite mineral powders are prepared quickly and efficiently by high-speed gas impact and cutting. The preparation process is fast, efficient, low-cost and suitable for large-scale production.

[0029] Step S130 specifically includes: in the process of graphite products or graphite minerals being ejected instantly from the inside of the high-pressure gas chamber, the external pressure relief speed of raw materials such as graphite minerals or graphite rod products is relatively fast, and the internal pressure relief speed is relatively slow, resulting in a high pressure gradient being formed inside and outside the graphite or graphite products in a very short time. This high pressure gradient is used to cause the graphite rods or graphite ore to expand and pulverize internally in a very short time to form graphene.

[0030] Among them, Figure 3 Shown is a diagram of the organizational structure of the prepared graphene under a microscope.

[0031] In this embodiment, the above method utilizes the difference in gas pressure inside and outside the material during the unloading process to cause the raw material to expand from the inside to the outside and pulverize, thereby rapidly preparing graphene with low cost and high preparation efficiency.

[0032] In the graphene preparation process, in order to further increase the gas pressure to enhance the pulverization effect, optionally, the pushing bin 5 and the external boosting device can be connected through a hose 4 to increase the gas pressure in the pushing bin 5 and the high-pressure bin 1 connected to the inside thereof.

[0033] In order to ensure the crushing effect when the hardness of the raw material is relatively high, in some embodiments, the other end of the high-pressure silo 1 is connected to a push silo 5 through a hose 4, and a high-pressure valve 51 is also provided on the side wall of the push silo 5. The push silo 5 is connected to an external booster device to increase the gas pressure in the push silo 5 and the high-pressure silo 1 connected to the inside thereof, thereby enhancing the crushing efficiency.

[0034] The boosting device may be a gas booster pump or other gas boosting equipment. In some embodiments, the boosting device for increasing the pressure of the push bin 5 and the high-pressure bin 1 includes: a gas booster pump or an air compressor or other device that can provide a high-pressure gas source.

[0035] In this embodiment, a connecting channel is established between the high-pressure silo 1 and the push silo 5, and the gas pressure is increased by an external booster device. Due to the increase in gas pressure, the pressure difference between the inside and outside of the instantaneously unloaded mineral is larger and the crushed product is more uniform, which helps to improve the quality and output of graphite or graphite mineral powder and improve the efficiency of preparing graphene.

[0036] Specifically, the connection between the high-pressure silo 1 and the unloading device 2 is a hose connection, a snap connection or a threaded connection. A sealing ring can be added at the connection to ensure the airtightness of the high-pressure cavity formed by the high-pressure silo 1 and the unloading device 2.

[0037] Continue to view Figure 2 The unloading device 2 includes a cavity, one end of which is a closed end and the other end is an opening, the opening end is connected to the high-pressure silo 1, and a mechanical valve or a part with a pressure control function is provided on the surface of the cavity.

[0038] Specifically, a pushing device is provided in the high-pressure silo 1. When there is no external force pushing, the pushing device is located near the other end of the high-pressure silo 1 connected to the pushing silo 5. Under the push of the gas pressure in the pushing silo 5, the pushing device moves in the high-pressure silo 1 to push the material in the high-pressure silo 1, so that the material quickly leaves the high-pressure silo 1 during the high-speed unloading process. The pushing device includes a sealing member made of a material with sealing properties, and the sealing material is generally silica gel or rubber, etc. During the pushing process, the sealing member is used to ensure that the high-pressure silo 1 is always in a sealed state.

[0039] As an optional embodiment of the present invention, the collection bin 3 is in the shape of a cylinder, cone, cube or rectangular parallelepiped tube structure, and is made of steel and aluminum alloy.

[0040] A flange 6 is installed on the outer wall of the high-pressure silo 1, and one end of the collecting bin 3 is connected to the flange 6 and fixed with bolts to enclose part of the structure of the high-pressure silo 1.

[0041] According to the above disclosure, the method for preparing graphene from graphite or graphite minerals based on high-speed gas unloading and gas-propelled graphite provided in the embodiment of the present invention provides an efficient and simple way to physically prepare graphene, by placing graphite products or graphite minerals in a high-pressure silo 1, and utilizing the high-pressure gas in the sealed high-pressure silo 1 to instantly release the high-pressure airflow generated by unloading, and the graphite products or graphite minerals in the high-pressure silo 1 are ejected together with the gas, expanded and pulverized to obtain graphene. It has low preparation cost, high preparation efficiency, and is easily suitable for large-scale production.

[0042] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing graphene from graphite products or graphite minerals based on gas high-speed unloading and gas-propelled, characterized in that: Includes steps: Placing graphite products or graphite minerals in a high-pressure silo, and connecting and closing one end of the high-pressure silo through an unloading device; after the unloading device is opened, the high-pressure silo is connected to the interior of the unloading device; Filling the high-pressure silo with a gas of a predetermined pressure, wherein the gas is carbon dioxide, nitrogen or air; Placing the unloading device and the high-pressure silo structure adjacent to the unloading device in the collecting bin; The unloading device is started, and the outlet of the unloading device is opened. The high-pressure gas in the silo is instantly released from the outlet. The gas pressure outside the graphite product or graphite mineral drops rapidly, while the inside of the graphite mineral still maintains high pressure. Under the action of the internal and external pressure difference, the graphite product or graphite mineral is crushed into graphite product or graphite mineral powder by the high-pressure gas, and enters the collecting bin from the outlet, so as to obtain graphite powder containing graphene.

2. The method for preparing graphene according to claim 1, characterized in that: The other end of the high-pressure silo is connected to a push silo through a hose, and the push silo is connected to an external booster device to increase the gas pressure in the push silo and the high-pressure silo connected to the interior thereof.

3. The method for preparing graphene according to claim 1 or 2, characterized in that: The predetermined pressure is 10 MPa~50 MPa.

4. The method for preparing graphene according to claim 1, characterized in that: The connection between the high-pressure silo and the unloading device is a hose connection, a snap connection or a threaded connection.

5. The method for preparing graphene according to claim 1, characterized in that: The unloading device comprises a cavity, one end of which is a closed end and the other end is an opening, the opening end is connected to the high-pressure silo, and a mechanical valve or a part with a pressure control function is provided on the surface of the cavity.

6. The method for preparing graphene according to claim 1, characterized in that: A pushing device is provided in the high-pressure silo, which pushes the material inside the high-pressure silo to quickly spray out of the high-pressure silo during the unloading process of the high-pressure silo. When there is no external force, the pushing device is located near the other end of the high-pressure silo connected to the pushing silo. Under the push of the gas pressure in the pushing silo, the pushing device moves in the high-pressure silo to push the material inside the silo to quickly spray out of the high-pressure silo.

7. The method for preparing graphene according to claim 1, characterized in that: The high-pressure silo and the push silo are mainly made of resin, glass fiber, steel or aluminum alloy.

8. The method for preparing graphene according to claim 1, characterized in that: The boosting device used to increase the pressure of the push bin and the high-pressure bin includes: a gas booster pump or an air compressor.

9. The method for preparing graphene according to claim 1, characterized in that: The collecting bin is in the shape of a cylinder, cone, cube or rectangular parallelepiped tube structure, and is made of steel and aluminum alloy.

10. The method for preparing graphene according to claim 1, characterized in that: A flange is installed on the outer side wall of the high-pressure silo, and one end of the collecting bin is connected to the flange and fixed with bolts to contain part of the structure of the high-pressure silo.

11. The method for preparing graphene according to claim 1, characterized in that: The graphite products include graphite products made of graphite electrodes, graphite pins or graphite core rods.

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