WO2017190570A1

WO2017190570A1 - Large-scale clean preparation method for graphene

Info

Publication number: WO2017190570A1
Application number: PCT/CN2017/078376
Authority: WO
Inventors: 陈庆; 曾军堂; 廖大应; 陈兵
Original assignee: 成都新柯力化工科技有限公司
Priority date: 2016-05-06
Filing date: 2017-03-28
Publication date: 2017-11-09
Also published as: CN105819437B; CN105819437A

Abstract

Provided is a large-scale clean preparation method for graphene, comprising: (i) preparing graphite raw material, water, foaming agent and surfactant into a suspension and stirring the suspension at a rotating speed of 300-500rpm to disperse the graphite raw material uniformly to obtain a dispersed suspension; (ii) feeding the dispersed suspension into a feed inlet (1) of a spraying device, the feed inlet communicating with a conveying chamber (2), the conveying chamber being internally provided with at least one ultrasonic probe (5); the dispersed suspension being subjected to ultrasonic treatment so that the foaming agent enters layers of graphite; the conveying chamber being internally provided with at least one air compressor (4) for pressurizing the dispersed suspension to accelerate the dispersed suspension to flow forward; the conveying chamber communicating with a drying chamber (3), and the dispersed suspension after treatment flowing into the drying chamber; and (iii) arranging a gas heating nozzle and at least one nozzle (7) at the top of the drying chamber; the dispersed suspension flowing through the nozzle and entering the drying chamber to be atomized by heated gas; the foaming agent being decomposed by heat so that interlayer spacing of graphite is increased; and after atomization and foaming, obtaining the graphene stripped off under a high-speed air flow. Preferably, at least one ultrasonic probe (6) is arranged at the nozzle. According to the method, two processes, i.e., mechanical stripping and drying, are integrated into a spray dryer and an ultrasonic device is arranged at the nozzle, thus providing graphite with a higher energy, increase the intercalating probability and improving the intercalating effect of the foaming agent. Hence, product quality is ensured and, environmental protection and no-pollution are achieved.

Description

Method for large-scale clean preparation of graphene

Technical field

The invention relates to a method for preparing graphene, in particular to a method for large-scale clean preparation of graphene.

Background technique

In 2004, two scientists at the University of Manchester in the United Kingdom discovered graphene using micromechanical stripping and won the Nobel Prize in Physics in 2010. Graphene is a planar structural material composed of a single atomic thickness of carbon atoms bonded by sp2 bonds. The carbon-carbon bond length is about 0.142 nm, and there are three σ bonds in each crystal lattice. The p orbitals of all carbon atoms. Both are perpendicular to the sp ² hybrid plane and form a delocalized π bond throughout the graphene side by side. In theory, this has a perfect hexagonal mesh structure and exhibits excellent electronic stability, thermal conductivity, optical properties, and mechanical properties. Since the discovery of graphene, due to its excellent performance and huge market application prospects, it has led to research booms in the fields of physics and materials science, making graphene have a very broad development prospect.

Large-scale preparation to obtain stable graphene is a prerequisite for the industrialization of graphene. At present, the preparation methods of graphene mainly include mechanical exfoliation method, epitaxial growth method, graphite oxide reduction method, chemical vapor deposition and the like. Since the preparation process of the graphite oxide reduction method is relatively simple, it is widely used by researchers. However, graphene synthesized by this method has many defects and oxidized groups, which limits its application in electronic devices. The mechanical stripping method can best preserve the properties of graphene, and the preparation method is simple, and the preparation process is environmentally friendly and non-polluting. The graphene preparation method widely used in the scientific research field is more and more popular in actual production. For example, Heim of the University of Manchester used tape to separate graphene from carbonaceous materials. Although this method of stripping graphene is simple, only a limited amount of graphene can be produced. Therefore, there is an urgent need to develop a preparation method capable of producing graphene on a large scale. The spray drying method is a method for preparing a nano dry powder by continuous atmospheric pressure, which uses a special device to spray the liquid material into a mist, which is dried in contact with hot air. The method has the advantages of fast drying speed, high product purity, good quality, good uniformity, fluidity and solubility. If the spray drying method is applied to the production of graphene, the defects of the current mechanical stripping method will be overcome, and a graphene product with high purity and uniformity can be obtained. And the production process is clean and environmentally friendly.

In order to achieve clean and environmentally large scale stripping of graphite to obtain graphene, in the prior art, Chinese Patent Application No. 201410846369.4 discloses an apparatus for producing graphene by spray drying and microwave, and a production process thereof, which comprises graphite in H ₂ Under the action of strong acid and strong oxidant such as SO ₄ and HNO ₃ , or under electrochemical peroxidation, hydrolyzed to form an aqueous solution of graphite oxide with a concentration of 0.1-50%; the raw material of the aqueous graphite oxide solution is dried by a peristaltic pump through an atomizer. In the indoor, the atomized state material is dissociated by microwave, and the material is reduced into flocculent and easy-flying graphene. The graphene after reduction is collected with the flowing air into the cyclone collecting device, and the material is loaded into the packaging bag through the wind shutoff discharge device. However, this method still uses a strong oxidizing agent to treat graphite, destroying the surface electronic topography of graphene, grafting a group such as a hydroxyl group or a carboxyl group, increasing the electrical resistance of graphene, and the use of a strong oxidizing agent also causes environmental pollution, and Bring safety hazards to the preparation staff.

Chinese Patent Application No. 201510777025.7 discloses a preparation method of large-sized graphene oxide or graphene, which under the action of intercalating agent and expanding agent, fully releases interlayer space to weaken interlayer interaction force, and obtain The graphene aggregates are dried by a spray drying method to obtain a graphene material. The raw material of the invention is cheap, the process is simple and easy to control, the solid-liquid separation is fast and efficient, and the industrialized large-scale production is facilitated, and the destruction of the crystal structure of the graphene oxide by high-energy ultrasonic waves, high-speed shearing or fluid pulverization is also avoided. However, in the production process, the method needs to wait for the graphite intercalation to be completed, and after the stripping is completed, it is spray-dried, that is, it cannot be continuously produced, and the production efficiency of graphene is lowered, so that the application is limited.

According to the above, the spray drying method is mostly used in the final step of graphene production, that is, the graphene solution which has been stripped is dried to prepare graphene powder. Moreover, if the strong oxidant is treated with graphite, the surface of the prepared graphene is grafted with a polar group, which is harmful to human health and causes environmental pollution, destroys the lattice integrity of the graphene, and reduces the conductivity of the system. Therefore, from the perspective of industrial demand, we need a large-scale, high-efficiency, zero-pollution integrated spray drying method for preparing graphene.

technical problem

The spray drying method is mostly used in the final step of graphene production, that is, the graphene solution which has been stripped is dried to prepare graphene powder. Moreover, if the strong oxidant is treated with graphite, the surface of the prepared graphene is grafted with polar groups, which is harmful to human health and causes environmental pollution, destroying the lattice integrity of graphene and reducing the lattice integrity. The electrical conductivity of the system. Therefore, from the perspective of industrial demand, we need a large-scale, high-efficiency, zero-pollution integrated spray drying method for preparing graphene.

Problem solution

Technical solution

In view of the current technical route for producing graphene by spray drying, the spray drying method is mostly used for drying graphene solution to prepare graphene powder. Moreover, if the strong oxidant is treated with graphite, the surface of the prepared graphene is grafted with a polar group, which is harmful to human health and causes environmental pollution, destroys the lattice integrity of the graphene, and reduces the conductivity of the system. If the stripping process of graphene or the chemical reduction process of graphene can also be carried out in a spray dryer, continuous mass production of graphene can be achieved. The invention provides a method for large-scale clean preparation of graphene, fully utilizes a spray drying device, integrates mechanical stripping and powder drying into a spray dryer, thereby realizing continuous, stable and environmentally clean preparation of graphene materials, and nanometer graphite. The olefin powder or micro-graphene powder is restricted in the drying chamber to ensure the health and life safety of the operator, which makes the graphene production chain clean and environmentally friendly, further promoting the industrial production of graphene dry powder.

In order to solve the above problems, the present invention adopts the following technical solutions:

A method for large-scale clean preparation of graphene, the specific method is as follows:

(1) 10-25 parts by weight of graphite raw material, 50-60 parts by weight of water, 1.5-15 parts by weight of a foaming agent, 1.5-5 parts by weight of a surfactant are formulated into a dispersion suspension, and stirred at 300-500 rpm. Dispersing for 10-25 min until the graphite raw material is uniformly dispersed in a solvent to obtain a dispersed suspension;

(2) adding the dispersed suspension solution obtained in the step (1) to the feed port of the spray device, the feed port is in communication with the feed chamber, and at least one ultrasonic probe is disposed inside the feed chamber, and the ultrasonic power is set to 100. -500 KW, after the dispersed suspension solution enters the feed chamber from the feed port, the dispersion suspension is subjected to ultrasonic treatment to allow the foaming agent to enter between the graphite layers to reduce the interaction between the graphite layers, in the feed chamber At least one air compressor is disposed inside, and the dispersion suspension is pressurized by the air compressor, and the dispersion suspension accelerates forward flow, and the delivery chamber is connected with the drying chamber, and the dispersion is suspended after ultrasonic treatment. Liquid flowing from the feed chamber into the drying chamber;

(3) providing a gas addition nozzle at the top of the drying chamber, maintaining a gas pressure of 0.1-0.5 MPa, a chamber temperature of 100-150 ° C, a heating gas temperature of 200-400 ° C, and setting at least one of the top ends of the drying chamber Nozzle, The dispersed suspension flows through the nozzle, enters the drying chamber, and is atomized by the heated gas. The foaming agent is decomposed by heat to release gas, and the distance between the graphite layers is increased. After atomization foaming, the graphite is subjected to high-speed airflow. Rapid stripping to obtain graphene.

Preferably, at least one ultrasonic probe is provided at the nozzle of the spray device, the ultrasonic power is set to be 100-500 KW, and a mechanical force is provided to cause ultrasonication of the graphite at the nozzle.

Preferably, the graphite raw material is at least one of flake graphite, expanded graphite, highly oriented graphite, pyrolytic graphite, and graphite oxide, and the graphite raw material has an average particle diameter of less than 1 mm; the foaming agent Is at least one of sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, ammonium chloride, ammonium sulfate, ammonium hydrogen sulfate, ammonium carbonate, ammonium hydrogencarbonate, ammonium phosphate; the surfactant is twelve At least one of sodium alkyl sulfate, sodium dodecylbenzenesulfonate, polyvinylpyrrolidone, and 1-pyridyl acid.

Preferably, the air flow rate in the air compressor described in the step (2) is 3-10 m/s.

Preferably, the gas in step (3) is one or more of nitrogen, argon and carbon dioxide.

Preferably, the nozzle has a size of 5 to 10 mm.

Preferably, a graphene collector is provided at the end of the drying chamber to collect graphene.

The existing spray drying method produces graphene. The spray drying method is mostly used for drying graphene solution to prepare graphene powder. Dust pollution is serious during the production process, and continuous production of graphene cannot be achieved. Moreover, if the strong oxidant is treated with graphite, the surface of the prepared graphene is grafted with a polar group, which is harmful to human health and causes environmental pollution, destroys the lattice integrity of the graphene, and reduces the conductivity of the system. If the stripping process of graphene or the chemical reduction process of graphene can also be carried out in a spray dryer, continuous mass production of graphene can be achieved. The invention provides a method for large-scale clean preparation of graphene, fully utilizes a spray drying device, integrates mechanical stripping and powder drying into a spray dryer, thereby realizing continuous, stable and environmentally clean preparation of graphene materials, and nanometer graphite. The olefin powder or micro-graphene powder is restricted in the drying chamber to ensure the health and life safety of the operator, making the graphene production chain clean and environmentally friendly, and promoting the industrial production of the graphene dry powder. Further, in the spray dryer, the shear stripping is completed in one step, and the dispersion is uniformized, thereby not only retaining the layer structure of the graphene to the utmost extent, but also continuously and stably preparing the graphene material without destroying the surface electrical topology symmetry of the graphene, further The quality of the finished graphene is guaranteed.

The present invention proposes a graphene prepared by a method for large-scale clean preparation of graphene as shown in Table 1.

Table 1:

Advantageous effects of the invention

Beneficial effect

The method for large-scale clean preparation of graphene of the invention has outstanding features and excellent effects compared with the prior art:

1. The invention integrates mechanical peeling and powder drying in a spray dryer to realize continuous, stable and environmentally clean preparation of graphene materials, and to limit nano graphene powder or micro graphene powder in a drying chamber. The treatment ensures the health and safety of the operators, making the graphene production chain clean and environmentally friendly, and promoting the industrial production of graphene dry powder.

2. The invention provides an ultrasonic device at the nozzle, provides higher energy for the graphite system through the cavitation of the ultrasonic, increases the probability of the graphite being intercalated, increases the intercalation effect of the foaming agent, and then increases the decomposition of the blowing agent at a high temperature. The spacing between the graphite layers, the graphite is stripped to obtain graphene, and the surface electrical symmetry of the graphene is not destroyed, further ensuring the quality of the finished graphene.

3. The graphene microchip material prepared by the method of the invention does not cause environmental pollution and meets environmental protection requirements.

Brief description of the drawing

DRAWINGS

In order to further clarify a method for large-scale clean preparation of graphene in the present invention, it will be described with reference to the accompanying drawings.

Figure 1 is a schematic view showing the outline of a scaled clean preparation graphene device. 1-feed port; 2-feed chamber; 3-drying chamber; 4-air compressor; 5,6-ultrasonic probe; 7-nozzle.

Invention embodiment

Embodiments of the invention

The invention is further described in detail below by way of specific examples, but it should not be construed that the scope of the invention is limited to the following examples. Various alterations and modifications may be made without departing from the spirit and scope of the invention.

Example 1

(1) 10 parts by weight of flake graphite having an average particle diameter of less than 1 mm, 50 parts by weight of water, 1.5 parts by weight of sodium carbonate, and 1.5 parts by weight of sodium lauryl sulfate as a dispersion suspension, and stirred at 300 rpm Dispersion was carried out for 10 min until the graphite raw material was uniformly dispersed in a solvent to obtain a dispersion suspension.

(2) adding the dispersed suspension solution obtained in the step (1) to the feed port of the spray device, the feed port is in communication with the feed chamber, and an ultrasonic probe is disposed inside the feed chamber, and the ultrasonic power is set to 100 KW. After the dispersed suspension solution enters the feed chamber from the feed port, the dispersion suspension is subjected to ultrasonic treatment to allow the foaming agent to enter between the graphite layers to reduce the interaction between the graphite layers, and at least one space is disposed inside the transfer chamber. Press, set the air flow rate in the air compressor to 3m / s, pressurize the dispersion suspension through the air compressor, the dispersion suspension accelerates forward flow, the feed chamber is connected with the drying chamber, after ultrasonic treatment The dispersed suspension flows from the feed chamber into the drying chamber.

(3) a gas addition nozzle is arranged on the top of the drying chamber, the gas pressure is 0.18 MPa, the chamber temperature is 100 ° C, the heating nitrogen temperature is 200 ° C, and a nozzle having a size of 5 mm is disposed at the top of the drying chamber. The dispersed suspension flows through the nozzle, enters the drying chamber and is atomized by the heated gas. The sodium carbonate is decomposed by heat to release gas, and the distance between the graphite layers is increased. After atomization foaming, the graphite is rapidly stripped under high-speed airflow, further One skilled in the art can provide at least one ultrasonic probe at the nozzle of the spray device as needed to provide mechanical force to ultrasonically cavitation the graphite at the nozzle. In this embodiment, an ultrasonic probe is disposed at the nozzle of the spray device, and the ultrasonic power is set to 100 KW. A graphene collector was placed at the end of the drying chamber to collect graphene.

The obtained graphene had a peeling rate of 90%, a graphene particle diameter of 1.8 μm, a thickness of 0.3 nm, and a uniform lateral size distribution.

Example 2

(1) 25 parts by weight of flake graphite having an average particle diameter of less than 1 mm, 60 parts by weight of water, 10 parts by weight of sodium carbonate, and 5 parts by weight of sodium lauryl sulfate as a dispersion suspension, and stirred at 400 rpm Dispersion was carried out for 10 min until the graphite raw material was uniformly dispersed in a solvent to obtain a dispersion suspension.

(3) providing a gas addition nozzle at the top of the drying chamber, maintaining a gas pressure of 0.2 MPa, a chamber temperature of 100 ° C, a heating nitrogen temperature of 200 ° C, and a nozzle having a size of 5 mm at the top of the drying chamber. The dispersed suspension flows through the nozzle, enters the drying chamber and is atomized by the heated gas. The sodium carbonate is decomposed by heat to release gas, and the distance between the graphite layers is increased. After atomization foaming, the graphite is rapidly stripped under high-speed airflow, further One skilled in the art can provide at least one ultrasonic probe at the nozzle of the spray device as needed to provide mechanical force to ultrasonically cavitation the graphite at the nozzle. In this embodiment, an ultrasonic probe is disposed at the nozzle of the spray device, and the ultrasonic power is set to 300 KW. A graphene collector was placed at the end of the drying chamber to collect graphene.

The obtained graphene had a peeling rate of 90%, a graphene particle diameter of 1.3 μm, a thickness of 0.5 nm, and a uniform lateral size distribution.

Example 3

(1) 25 parts by weight of expanded graphite having an average particle diameter of less than 1 mm, 60 parts by weight of water, 10 parts by weight of sodium carbonate and sodium hydrogencarbonate mixture, and 5 parts by weight of sodium dodecylbenzenesulfonate are formulated to be dispersed and suspended. The liquid was stirred and dispersed at 400 rpm for 15 minutes until the expanded graphite was uniformly dispersed in the solvent to obtain a dispersion suspension.

(2) adding the dispersed suspension solution obtained in the step (1) to the feed port of the spray device, the feed port is connected to the feed chamber, and two ultrasonic probes are arranged inside the feed chamber, and the ultrasonic power is set to 200 KW. After the dispersed suspension solution enters the feed chamber from the feed port, the dispersion suspension is subjected to ultrasonic treatment to allow the foaming agent to enter between the graphite layers to reduce the interaction between the graphite layers, and at least one air pressure is disposed inside the feed chamber. Machine, setting The air flow rate in the air compressor is 6m/s, the dispersion suspension is pressurized by the air compressor, the dispersion suspension accelerates forward flow, the feed chamber communicates with the drying chamber, and the dispersion is suspended after sonication. The liquid flows from the feed chamber into the drying chamber.

(3) a gas addition nozzle is arranged on the top of the drying chamber, the gas pressure is 0.3 MPa, the chamber temperature is 100 ° C, the heating nitrogen temperature is 200 ° C, and a nozzle having a size of 5 mm is disposed at the top of the drying chamber. The dispersed suspension flows through the nozzle, enters the drying chamber and is atomized by the heated gas. The sodium carbonate is decomposed by heat to release gas, and the distance between the graphite layers is increased. After atomization foaming, the graphite is rapidly stripped under high-speed airflow, further One skilled in the art can provide at least one ultrasonic probe at the nozzle of the spray device as needed to provide mechanical force to ultrasonically cavitation the graphite at the nozzle. In this embodiment, an ultrasonic probe is disposed at the nozzle of the spray device, and the ultrasonic power is set to 300 KW. A graphene collector was placed at the end of the drying chamber to collect graphene.

The obtained graphene had a peeling rate of 90%, a graphene particle diameter of 2.4 μm, a thickness of 0.3 nm, and a uniform lateral size distribution.

Example 4

(2) adding the dispersed suspension solution obtained in the step (1) to the feed port of the spray device, the feed port is connected to the feed chamber, and two ultrasonic probes are arranged inside the feed chamber, and the ultrasonic power is set to 200 KW. After the dispersed suspension solution enters the feed chamber from the feed port, the dispersion suspension is subjected to ultrasonic treatment to allow the foaming agent to enter between the graphite layers to reduce the interaction between the graphite layers, and at least one air pressure is disposed inside the feed chamber. Machine, set the air flow rate in the air compressor to 6m / s, pressurize the dispersion suspension through the air compressor, the dispersion suspension accelerates forward flow, the feed chamber is connected with the drying chamber, after ultrasonic treatment The dispersed suspension flows from the feed chamber into the drying chamber.

(3) A gas addition nozzle is arranged at the top of the drying chamber, the gas pressure is 0.4 MPa, the chamber temperature is 150 ° C, the heating nitrogen temperature is 300 ° C, and a nozzle of a size of 10 mm is disposed at the top of the drying chamber, and is dispersed. The turbid liquid flows through the nozzle, enters the drying chamber and is atomized by the heated gas. The sodium carbonate and sodium hydrogencarbonate are decomposed by heat to release the gas, and the distance between the graphite layers is increased. After atomization foaming, the graphite is fast under high-speed airflow. Speed stripping, further, one skilled in the art can provide at least one ultrasonic probe at the spray device nozzle as needed to provide mechanical force to ultrasonically cavitation of graphite at the nozzle. In this embodiment, an ultrasonic probe is disposed at the nozzle of the spray device, and the ultrasonic power is set to 300 KW. A graphene collector was placed at the end of the drying chamber to collect graphene.

The obtained graphene had a peeling rate of 90%, a graphene particle diameter of 2.6 μm, a thickness of 0.3 nm, and a uniform lateral size distribution.

Example 5

(1) 25 parts by weight of expanded graphite having an average particle diameter of less than 1 mm, 60 parts by weight of water, 10 parts by weight of sodium carbonate and sodium hydrogencarbonate mixture, and 5 parts by weight of sodium dodecylbenzenesulfonate are formulated to be dispersed and suspended. The liquid was stirred and dispersed at 500 rpm for 15 minutes until the expanded graphite was uniformly dispersed in the solvent to obtain a dispersion suspension.

(2) adding the dispersed suspension solution obtained in the step (1) to the feed port of the spray device, the feed port is connected to the feed chamber, and two ultrasonic probes are arranged inside the feed chamber, and the ultrasonic power is set to 500 KW. After the dispersed suspension solution enters the feed chamber from the feed port, the dispersion suspension is subjected to ultrasonic treatment to allow the foaming agent to enter between the graphite layers to reduce the interaction between the graphite layers, and at least one air pressure is disposed inside the feed chamber. Machine, set the air flow rate in the air compressor to 10m / s, pressurize the dispersion suspension through the air compressor, the dispersion suspension accelerates forward flow, the feed chamber is connected with the drying chamber, after ultrasonic treatment The dispersed suspension flows from the feed chamber into the drying chamber.

(3) Providing a gas addition nozzle at the top of the drying chamber, maintaining a gas pressure of 0.5 MPa, a chamber temperature of 150 ° C, a heating nitrogen temperature of 400 ° C, and a nozzle of a size of 10 mm at the top of the drying chamber, dispersed and suspended The turbid liquid flows through the nozzle, enters the drying chamber and is atomized by the heated gas. The sodium carbonate and sodium hydrogencarbonate are decomposed by heat to release the gas, and the distance between the graphite layers is increased. After atomization foaming, the graphite is quickly stripped under high-speed airflow. Further, one skilled in the art can provide at least one ultrasonic probe at the nozzle of the spray device as needed to provide mechanical force to ultrasonically cavitation the graphite at the nozzle. In this embodiment, two ultrasonic probes are disposed at the nozzle of the spray device, and the ultrasonic power is set to 500 KW. A graphene collector was placed at the end of the drying chamber to collect graphene.

The obtained graphene had a peeling rate of 90%, a graphene particle diameter of 0.8 μm, a thickness of 0.3 nm, and a uniform lateral size distribution.

Industrial applicability

The invention provides a method for large-scale clean preparation of graphene, fully utilizes a spray drying device, integrates mechanical stripping and powder drying into a spray dryer, thereby realizing continuous, stable and environmentally clean preparation of graphene materials, and nanometer graphite. The olefin powder or micro-graphene powder is restricted in the drying chamber to ensure the health and life safety of the operator, which makes the graphene production chain clean and environmentally friendly, further promoting the industrial production of graphene dry powder.

Claims

A method for large-scale clean preparation of graphene, the specific method is as follows:

(1) 10-25 parts by weight of graphite raw material, 50-60 parts by weight of water, 1.5-15 parts by weight of a foaming agent, 1.5-5 parts by weight of a surfactant are formulated into a dispersion suspension, and stirred at 300-500 rpm. Dispersing for 10-25 min until the graphite raw material is uniformly dispersed in a solvent to obtain a dispersed suspension;

(2) adding the dispersed suspension solution obtained in the step (1) to the feed port of the spray device, the feed port is in communication with the feed chamber, and at least one ultrasonic probe is disposed inside the feed chamber, and the ultrasonic power is set to 100. -500 KW, after the dispersed suspension solution enters the feed chamber from the feed port, the dispersion suspension is subjected to ultrasonic treatment to allow the foaming agent to enter between the graphite layers to reduce the interaction between the graphite layers, in the feed chamber At least one air compressor is disposed inside, and the dispersion suspension is pressurized by the air compressor, and the dispersion suspension accelerates forward flow, and the delivery chamber is connected with the drying chamber, and the dispersion is suspended after ultrasonic treatment. Liquid flowing from the feed chamber into the drying chamber;

(3) providing a gas addition nozzle at the top of the drying chamber, maintaining a gas pressure of 0.1-0.5 MPa, a chamber temperature of 100-150 ° C, a heating gas temperature of 200-400 ° C, and setting at least one of the top ends of the drying chamber The nozzle flows through the nozzle through the dispersed suspension, enters the drying chamber and is atomized by the heating gas, and the foaming agent is decomposed by heat to release gas, and the spacing of the graphite layer is increased, and after atomization foaming, the graphite is in a high-speed airflow. The underside is quickly stripped to obtain graphene.
A method for large-scale clean preparation of graphene according to claim 1, wherein at least one ultrasonic probe is disposed at the nozzle of the spray device, and the ultrasonic power is set to be 100-500 KW, and mechanical force is provided to make the graphite in place. Ultrasonic cavitation at the nozzle.
The method for preparing a graphene according to claim 1, wherein the graphite material is at least one of flake graphite, expanded graphite, highly oriented graphite, pyrolytic graphite, and graphite oxide. The graphite material has an average particle diameter of less than 1 mm; the foaming agent is sodium carbonate, potassium carbonate, sodium hydrogencarbonate or hydrogen carbonate. At least one of potassium, ammonium chloride, ammonium sulfate, ammonium hydrogen sulfate, ammonium carbonate, ammonium hydrogencarbonate, ammonium phosphate; the surfactant is sodium lauryl sulfate, sodium dodecylbenzenesulfonate At least one of polyvinylpyrrolidone and 1-pyridyl acid.
A method for large-scale clean preparation of graphene according to claim 1, wherein the air flow rate in the air compressor described in the step (2) is 3-10 m/s.
A method for preparing graphene by mass cleaning according to claim 1, wherein the gas in the step (3) is one or more of nitrogen, argon and carbon dioxide.
A method for preparing graphene by mass cleaning according to claim 1, wherein the nozzle has a size of 5 to 10 mm.
A method for large-scale clean preparation of graphene according to claim 1, wherein a graphene collector is disposed at an end of the drying chamber to collect graphene.