Preparation method of graphene powder material

Abstract

The invention discloses a preparation method of a graphene powder material, and particularly relates to the technical field of powder material mixing, and the preparation method comprises the following steps: putting graphene powder into a main feeding hopper, putting auxiliary powder into an auxiliary feeding hopper, and controlling an adhesion belt to continuously move, so that a graphene powder layer and an auxiliary powder layer superposed on the graphene powder layer are conveyed backwards together; and the stirring assembly is started to conduct secondary stirring and mixing on the premixed powder materials in the stirring bin, the stirring assembly is closed, and the mixed powder materials are taken out. By means of limitation of the output gap of the main extension pipe and the output gap of the auxiliary extension pipe, the auxiliary powder can be evenly laid on the preformed graphene powder layer, then different powder materials are evenly distributed in advance, the agglomeration phenomenon of the graphene powder is effectively prevented, and the production efficiency is improved. Therefore, the bonding uniformity between the graphene powder and the auxiliary powder can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of powder material mixing, and more specifically, to a method for preparing a graphene powder material. Background Art

[0002] Graphene is a new material with carbon atoms connected by sp² hybridization tightly stacked into a single-layer two-dimensional honeycomb lattice structure. Graphene has excellent optical, electrical and mechanical properties, and has important application prospects in materials science, micro-nano processing, energy, biomedicine and drug delivery, and is considered to be a revolutionary material in the future.

[0003] Graphene is essentially a two-dimensional material composed of a single layer of carbon atoms. However, in practical applications, graphene is mainly prepared in powder form for ease of storage, transportation and processing. In addition, in order to improve and give full play to the excellent properties of graphene (such as conductivity, thermal conductivity, mechanical reinforcement, etc.) and disperse it evenly in the target material, it is necessary to pre-mix the graphene powder material with other related raw materials (in powder form), such as catalysts, conductive agents, initiators and other materials.

[0004] Among them, the mixing of the above-mentioned powder materials is mainly carried out using a stirring mixer, and the various materials are put into the stirring mixer at the same time according to the material ratio in advance (or gradually put in from a hopper). For the production of large quantities of graphene powder materials, in order to improve production efficiency, a larger capacity stirring mixer will be used, and a large amount of powder material will be put in at one time to speed up the mixing speed.

[0005] However, when the graphene powder material is put into the mixer directly, the space in the mixer cavity is relatively large, and the amount of graphene powder material put into the mixer at one time is relatively large. The graphene powder material has enough space to gather and is difficult to disperse for a while.

[0006] In particular, graphene powder still has strong van der Waals force and electrostatic force in the dry state, which makes it easy for the flakes to attract each other and stack, forming agglomeration of graphene powder, which in turn causes the graphene powder material to form agglomerates of different sizes each time it is put in. The more graphene powder material is put in at a time, the larger the mixer space is, the more agglomerates are formed, and it is not easy to fully mix with other materials. Even if most of the larger agglomerated powder materials can be broken up by the agitator in the mixer, there will still be many smaller micro-agglomerated graphene powder materials. Due to the adsorption of graphene powder to other materials, many tiny "small balls" of other materials are formed, which leads to insufficient and uneven mixing, which greatly affects the performance of the final graphene material (for example, when making electrode materials, adhesives, catalysts, and conductive agents need to be added. If graphene cannot be evenly mixed with the raw materials, it will greatly affect the balance of the electrode, increase the internal resistance, and reduce the electrode performance). Summary of the invention

[0007] The present invention provides a method for preparing a graphene powder material, and aims to solve the following problem: in the existing mixing scheme, since the space in the mixer cavity is relatively large when the graphene powder material is put in, the graphene powder material has enough space to gather, resulting in more agglomeration of the graphene powder, which in turn affects the mixing effect of different materials.

[0008] To achieve the above object, the present invention provides the following technical solution: a method for preparing a graphene powder material, using a secondary mixing device to mix graphene powder and auxiliary powder, comprising the following steps: Step 1: Put the graphene powder into the main upper hopper, so that the powder material in the main upper hopper contacts the attachment belt through the main extension tube, and then drive the attachment belt to move, through the output gap of the main extension tube, so that the excess graphene powder is blocked in the main extension tube, and the graphene powder layer attached to the attachment belt is output; Step 2: After the graphene powder layer reaches the bottom of the secondary extension tube, the auxiliary powder is put into the secondary upper hopper, so that the auxiliary powder in the secondary upper hopper contacts the graphene powder layer already formed on the attachment belt through the secondary extension tube, and the attachment belt is continuously driven to transport, and the excess auxiliary powder is blocked in the secondary extension tube through the output gap of the secondary extension tube, and the auxiliary powder layer attached to the graphene powder layer on the attachment belt is output; Step 3: Control the attachment belt to keep moving, so that the graphene powder layer and the auxiliary powder layer superimposed thereon are transported backward together, until they are transported to the material drop area, and the graphene powder material and the auxiliary powder material are separated from the attachment belt and fall down; Step 4: The powder material separated from the attachment belt falls into the mixing bin for collection. After all the materials in the main upper hopper and the auxiliary upper hopper are output, the mixing component is started to perform secondary mixing on the pre-mixed powder material in the mixing bin. Step 5: Close the stirring assembly, open the closed door at the discharge port at the bottom of the stirring bin, and take out the mixed powder material.

[0009] In a preferred embodiment, the secondary mixing device includes a mixer and a feeder, the mixer includes a stirring bin and a pre-mixing bin, the pre-mixing bin is arranged on the stirring bin, the feeder includes a main feed hopper and an auxiliary feed hopper, the main feed hopper and the auxiliary feed hopper are both installed on the pre-mixing bin, a stirring assembly is arranged in the stirring bin, a layered mixing assembly is arranged in the pre-mixing bin, the layered mixing assembly includes an attachment belt and a belt roller, the attachment belt is a belt-type annular structure, the attachment belt is made of rubber, at least two groups of belt rollers are arranged, the belt rollers support the attachment belt to form a conveying structure, a conveying area is formed above the attachment belt, and the attachment belt conveying area A material dropping area is formed at the conveying end of the domain, and a main extension tube is arranged at the bottom of the main upper hopper, and a secondary extension tube is arranged at the bottom of the secondary upper hopper, and the bottom ports of the main extension tube and the secondary extension tube are arranged corresponding to the conveying area of ​​the attachment belt, and input gaps and output gaps are respectively formed on both sides of the main extension tube and the areas corresponding to the attachment belt on both sides of the secondary extension tube, and the input gaps and the output gaps are arranged in sequence along the conveying direction of the attachment belt, and along the conveying direction of the attachment belt, the output gaps of the main extension tube and the secondary extension tube are arranged to increase in sequence, and flat pressure guide plates are arranged at the output gaps of the main extension tube and the secondary extension tube.

[0010] In a preferred embodiment, an air nozzle is provided outside the blanking area of ​​the attachment belt, and multiple groups of air nozzles are provided. An air equalization bin is provided in the premixing bin, and the air equalization bin is connected to a fan duct, and the fan duct is connected to a fan structure. The air nozzle is used to blow air downward through the fan structure and blow it toward the arc surface at the matching point between the attachment belt and the belt roller in the blanking area to blow away the powder material on the attachment belt.

[0011] In a preferred embodiment, a cleaning brush is provided below the blanking area of ​​the attachment belt, and the bristles of the cleaning brush are in contact with the attachment belt. When the attachment belt moves, the residual powder material on the surface of the attachment belt is cleaned by the cleaning brush. A vibration seat is also provided in the premixing bin, and the vibration seat is installed in the premixing bin through an elastic member. A vibrator is fixedly installed on the vibration seat, and a vibration roller is rotatably installed on the vibration seat. The vibration roller is in contact with a position of the attachment belt away from the conveying area, and the corresponding area of ​​the attachment belt is driven to vibrate through the vibration seat to shake the residual powder material on the surface of the attachment belt downward.

[0012] In a preferred embodiment, a humidifying chamber is provided in the lower area of ​​the attachment belt, and an atomizing nozzle is provided in the humidifying chamber. When the attachment belt passes through the humidifying chamber, the humidity on the surface of the attachment belt is increased by the atomizing nozzle. An air heater is installed in the gas equalizing chamber, and the gas before being blown out of the air nozzle is heated by the air heater. A filtering exhaust pipe is provided in the premixing chamber, and the filtering exhaust pipe is connected to the fan structure connected to the fan pipe.

[0013] In a preferred embodiment, a wiping roller is provided at the position where the side wall of the humidification chamber cooperates with the attachment belt. The wiping roller is rotatably installed on the top of the side wall of the humidification chamber. The surface of the wiping roller is a sponge layer structure. Through the rolling cooperation between the wiping roller and the attachment belt, excess moisture on the surface of the attachment belt is scraped off and absorbed.

[0014] In a preferred embodiment, in step one and step two, after adding the corresponding powder materials into the main upper hopper and the auxiliary upper hopper, a plurality of grinding balls are put into the main upper hopper and the auxiliary upper hopper, so that the grinding balls sink under the action of their own weight and gather at the main extension tube and the auxiliary extension tube. A supporting pad is provided on the inner side of the attachment belt, and the movement of the attachment belt cooperates with the corresponding grinding balls to make the grinding balls roll and move accordingly, thereby stirring and squeezing the corresponding powder materials downward.

[0015] In a preferred embodiment, after the grinding balls are added, a covering bag is placed in both the main upper hopper and the auxiliary upper hopper, and a plurality of groups of metal particles are filled in the covering bag so that the covering bag is laid flat on the corresponding powder material.

[0016] In a preferred embodiment, the flat pressure guide plate in the main extension tube is slidably installed in the main extension tube, and the flat pressure guide plate in the secondary extension tube is slidably installed in the secondary extension tube, and both the main extension tube and the secondary extension tube are provided with a distance adjuster for controlling the movement of the flat pressure guide plate, wherein the sliding direction of the flat pressure guide plate is inclined relative to the conveying direction of the attachment belt conveying area, and the position of the corresponding flat pressure guide plate is controlled by the distance adjuster to adjust the cross-sectional size and output gap size of the corresponding main extension tube or secondary extension tube.

[0017] In a preferred embodiment, the attachment belt includes a base belt and a thin-walled elastic belt. The base belt is located in the inner circle, and multiple groups of filling strips are arranged at the base belt corresponding to the thin-walled elastic belt. The elastic coefficient of the thin-walled elastic belt is greater than the elastic coefficient of the base belt. When the attachment belt moves to the belt roller in the blanking area, an arc area is formed, and the thin-walled elastic belt is stretched.

[0018] The beneficial effect of the present invention is that: the present invention uses the output gap of the main extension tube to block excess graphene powder in the main extension tube, outputs a thinner graphene powder layer attached to the attachment belt, and is restricted by the output gap of the secondary extension tube so that the auxiliary powder can be evenly laid on the pre-formed graphene powder layer, thereby achieving pre-uniform distribution of different powder materials, so that when the powder material leaves the attachment belt, it can be directly evenly mixed, and due to the restriction of the output gap, there is not enough space for the graphene powder to agglomerate, so that the uniformity of the combination between the graphene powder and the auxiliary powder can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of the preparation method of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure of the secondary mixing equipment used in the preparation method of the present invention.

[0021] Figure 3 It is a schematic diagram of the internal structure of the secondary mixing device of the present invention.

[0022] Figure 4 It is a schematic diagram of the cooperation between the main extension tube, the auxiliary extension tube and the attachment belt of the present invention.

[0023] Figure 5 This is a state diagram of the air nozzle of the present invention blowing air toward the drop area at the end of the attachment belt to accelerate the mixed powder to separate and fall.

[0024] Figure 6 It is a schematic diagram of the structure of the improved layered mixing assembly of the present invention.

[0025] Figure 7 For the present invention Figure 6 A magnified view of the structure of section A.

[0026] Figure 8 The figure is a schematic diagram of the structure of the improved feeding assembly according to the present invention.

[0027] Fig. 9 For the present invention Figure 8 Enlarged view of the structure of part B in .

[0028] Fig.10 A detailed structural schematic diagram of the attachment tape of the present invention.

[0029] Fig.11 The present invention Fig.10 Enlarged view of the C structure in .

[0030] The accompanying drawings are marked as follows: 1. mixer; 11. stirring chamber; 12. pre-mixing chamber; 121. gas equalizing chamber; 122. fan duct; 123. air heater; 124. humidifying chamber; 125. filter exhaust pipe; 2. loader; 21. main hopper; 211. main extension pipe; 22. auxiliary hopper; 221. auxiliary extension pipe; 23. flat pressure guide plate; 24. grinding ball; 25. covering bag; 26. distance adjuster; 3. layered mixing assembly; 31. attachment belt; 311. base belt; 312. filling strip; 313. thin-walled elastic belt; 32. belt roller; 33. cleaning brush; 34. support pad; 35. vibration seat; 36. beam pressure roller; 4. stirring assembly; 41. stirring shaft; 42. stirring blade; 5. air nozzle; 6. atomizing nozzle; 7. wiping roller. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0032] Refer to the instruction manual Figure 1 and 2A method for preparing a graphene powder material, wherein the preparation method uses a secondary mixing device to mix graphene powder and other auxiliary powders (such as adhesives, catalysts, and conductive agents) to be added, wherein the secondary mixing device includes a mixer 1 and a feeder 2, the mixer 1 includes a stirring bin 11 and a pre-mixing bin 12, the pre-mixing bin 12 is arranged on the stirring bin 11, the feeder 2 includes a main feeder 21 and a secondary feeder 22, the main feeder 21 and the secondary feeder 22 are both installed on the pre-mixing bin 12, the stirring bin 11 is provided with a stirring component 4, and the pre-mixing bin 12 is provided with a layered mixing component 3 The layered mixing assembly 3 includes an attachment belt 31 and a belt roller 32. The attachment belt 31 is a belt-type annular structure. The belt roller 32 is provided with at least two groups. The two groups of belt rollers 32 support the attachment belt 31 to form a conveying structure similar to a conveying belt. At least one group of the attachment belt 31 is driven to rotate by a driving device to form a driving force for the attachment belt 31. Under the support of the attachment belt 31, a conveying area is formed above the attachment belt 31. A material dropping area is formed at the conveying end along the conveying direction of the conveying area of ​​the attachment belt 31, that is, at the belt roller 32 corresponding to the position. The material dropping area corresponds to the mixing bin 11, and the bottom of the main upper hopper 21 A main extension pipe 211 is provided at the bottom of the auxiliary upper hopper 22, and a secondary extension pipe 221 is provided at the bottom of the auxiliary upper hopper 22. The bottom ports of the main extension pipe 211 and the secondary extension pipe 221 are arranged corresponding to the conveying area of ​​the attachment belt 31, and corresponding gaps are formed, that is, the main extension pipe 211 and the secondary extension pipe 221 are not directly in contact with the attachment belt 31, and the areas corresponding to the attachment belt 31 on both sides of the main extension pipe 211 and the areas corresponding to the attachment belt 31 are respectively formed with input gaps and output gaps, and the input gaps and the output gaps are arranged in sequence along the conveying direction of the attachment belt 31 (that is, they are arranged in sequence corresponding to the conveying direction of the conveying area of ​​the attachment belt 31), and along the attachment belt 31 In the conveying direction, the output gaps of the main extension tube 211 and the auxiliary extension tube 221 are set to increase in sequence (wherein the main upper hopper 21 is mainly used to put graphene powder, so only one is needed, and the auxiliary upper hopper 22 is used to put other auxiliary powders, so one can be set to put all the auxiliary powders at the same time, or multiple can be set to put the corresponding auxiliary powders respectively, so when the number of auxiliary upper hoppers 22 is set to multiple, the output gap of each auxiliary upper hopper 22 is also gradually increased along the output direction of the attachment belt 31), and the output gaps of the main extension tube 211 and the auxiliary extension tube 221 are both provided with flat pressure guide plates 23.

[0033] Specifically, the preparation method comprises the following steps: Step 1: Put the graphene powder into the main upper hopper 21, so that the powder material in the main upper hopper 21 contacts the attachment belt 31 through the main extension tube 211. The attachment belt 31 is mainly made of rubber and has tiny pores on its surface. The graphene powder directly contacting the attachment belt 31 will form an attachment layer, and then drive the attachment belt 31 to start preliminary movement, so that the area of ​​the attachment belt 31 initially attached with the graphene powder moves backward, and with the help of the output gap of the main extension tube 211, the excess graphene powder is blocked in the main extension tube 211 (even if the graphene powder in the main extension tube 211 is agglomerated, the output gap size is limited, and the output graphene powder that can be attached to the attachment belt 31 forms a thin attachment layer), and finally outputs a thin graphene powder layer attached to the attachment belt 31, and the graphene powder layer is transported backward to the secondary extension tube 221 following the transportation of the attachment belt 31; Step 2: After the initially formed graphene powder layer completely reaches the bottom of the secondary extension tube 221, other auxiliary powders that need to be mixed are put into the secondary upper hopper 22 (in actual preparation, all auxiliary powders can be pre-mixed and put into one secondary upper hopper 22 at the same time according to needs, or a corresponding number of secondary upper hoppers 22 can be set according to needs, and corresponding auxiliary powders can be put in respectively), so that the auxiliary powder in the secondary upper hopper 22 contacts the powder layer already formed on the attachment belt 31 (i.e., the initially formed graphene powder layer) through the secondary extension tube 221, and the attachment belt 31 is continuously driven for transportation. At this time, since the output gap of the secondary extension tube 221 is larger than the output gap of the previous main extension tube 211, the auxiliary powder can be evenly spread and attached to the graphene powder layer. Due to the limitation of the output gap, there is not enough space for the graphene powder to agglomerate, so the bonding uniformity between the graphene powder and the auxiliary powder can be effectively improved; Step 3: Control the attachment belt 31 to continuously move, so that the graphene powder layer and the auxiliary powder layer superimposed thereon are transported backwards together. When transported to the material drop area, since an arc structure is formed between the attachment belt 31 and the belt roller 32, the powder begins to fall under the action of gravity. Since the auxiliary separation medium and the graphene powder are already in a layered state superimposed on each other in the previous step, they are also in a uniform pre-mixed state when they are separated from the attachment belt 31 at this time; Step 4: The powder material separated from the attachment belt 31 falls into the mixing bin 11 for collection. After all the materials in the main upper hopper 21 and the auxiliary upper hopper 22 are output, the stirring assembly 4 is driven to start operating, and the pre-mixed powder material in the mixing bin 11 is stirred and mixed for the second time to further improve the mixing uniformity. Step 5: close the stirring assembly 4, open the closed door at the bottom discharge port of the stirring bin 11, and take out the completely mixed powder material.

[0034] It should be noted that the flat pressing guide plate 23 is a plate-like structure whose main body is parallel to the attachment belt 31. The output gap is actually the area formed between the flat pressing guide plate 23 and the attachment belt 31, and both ends of the flat pressing guide plate 23 are composed of an upturned structure. Therefore, when each powder material follows the attachment belt 31 and passes through the flat pressing guide plate 23, while ensuring that excess powder is blocked, the corresponding powder material can also be effectively squeezed to ensure that the powder materials added in different layers can be fully mixed.

[0035] For further information, please refer to the attached manual. Figure 3 In order to make the powder material fully fall in the blanking area of ​​the attachment belt 31, the present embodiment also provides the following method. Specifically, an air nozzle 5 is arranged outside the blanking area of ​​the attachment belt 31. The air nozzle 5 is used to blow out airflow downward, so that the airflow is blown onto the arc surface of the matching place between the attachment belt 31 and the belt roller 32 in the blanking area to accelerate the separation of each layer of powder material. When separating, since each layer of powder material has been evenly laid, when it is separated from the attachment belt 31 into the air, the previously laid layers will be pre-installed to produce mutual dispersion and mixing. In addition, the blowing of the airflow can make the powder materials more fully fused, improve the mixing efficiency, and ensure that the powder materials can fully separate and fall in the blanking area.

[0036] Among them, the air nozzles 5 are provided with multiple groups, and an air equalization bin 121 is provided in the pre-mixing bin 12. The air equalization bin 121 is connected with a fan duct 122, and the fan duct 122 is connected with a fan structure (an air pump can also be used to provide a strong airflow). Then, under the neutralization of the air equalization bin 121, multiple air nozzles 5 blow air downward at the same time to form a uniform blowing airflow with a large coverage area, thereby improving the efficiency of the powder material falling into the mixing bin 11.

[0037] At the same time, in order to prevent the residual powder on the attachment belt 31 from following and returning to the main upper hopper 21 and the auxiliary upper hopper 22 again, the present embodiment further provides a cleaning brush 33 below the dropping area of ​​the attachment belt 31. The cleaning brush 33 is fixedly installed in the premixing bin 12, and the bristles of the cleaning brush 33 are in contact with the portion of the attachment belt 31 located in the lower area. Therefore, when the attachment belt 31 moves, the residual powder on the surface of the attachment belt 31 can be cleaned with the help of the cleaning brush 33, thereby ensuring the subsequent use effect of the attachment belt 31.

[0038] In addition, in order to improve the mixing effect, the present embodiment also improves the layered mixing assembly 3, for example, referring to the attached Figure 6In order to further avoid the powder material from remaining after the attachment belt 31 passes through the drop area, the present embodiment further provides a vibration seat 35 in the premixing bin 12, and the vibration seat 35 is installed in the premixing bin 12 through an elastic member (such as a spring, a rubber block or a combination structure of a spring and a slide rod), and a vibrator is fixedly installed on the vibration seat 35, and a vibration roller is rotatably installed on the vibration seat 35, and the vibration roller contacts the position of the attachment belt 31 away from the conveying area, and the vibration seat 35 drives the corresponding area of ​​the attachment belt 31 to vibrate so as to shake the powder material remaining on the surface of the attachment belt 31 downward, and at the same time, the premixing bin 12 is further provided with a compression roller 36 at the positions on both sides of the vibration seat 35, and the compression roller 36 is composed of two sets of upper and lower limiting rollers, and the two sets of limiting rollers are both rollingly matched with the attachment belt 31, so that the attachment belt 31 can pass through the upper and lower two sets of limiting rollers, thereby ensuring that the attachment belt 31 in other areas does not vibrate.

[0039] Among them, since the attachment belt 31 is in a continuous operation state, and the attachment belt 31 is mainly made of rubber material, static electricity is likely to occur during operation, resulting in excessive adsorption of various types of powders, and due to the uncertainty of the static electricity area, the adsorption effect is difficult to determine, and the subsequent static electricity is not easy to eliminate, resulting in the subsequent powder is not easy to detach. For this reason, the present embodiment also provides the following scheme. Specifically, an atomizing nozzle 6 is arranged in the lower area of ​​the attachment belt 31, and a humidifying bin 124 is arranged in the pre-mixing bin 12 corresponding to the lower area of ​​the attachment belt 31. The atomizing nozzle 6 is arranged in the humidifying bin 124. The atomizing nozzle 6 is connected to the water pump system, and when the attachment belt 31 is running, the atomizing nozzle 6 is used to humidify the humidification chamber 124 area, thereby increasing the humidity on the surface of the attachment belt 31 (it should be noted that there is no need to form a large water layer on the surface of the attachment belt 31, otherwise water droplets are easily formed, affecting the attachment effect), thereby effectively reducing the static electricity phenomenon. At the same time, the humidity on the surface of the attachment belt 31 is increased in advance. When it passes through the main extension tube 211 and the auxiliary extension tube 221, the tiny water film evenly distributed on the surface of the attachment belt 31 can be used to enhance the adsorption effect on the powder material, thereby improving the uniformity of mixing multiple powder materials.

[0040] Further, in order to control the effect of the water film on the surface of the attachment tape 31, refer to the attached manual. Figure 7 A wiping roller 7 can also be provided at the position where the side wall of the humidifying chamber 124 cooperates with the attachment belt 31. The wiping roller 7 is rotatably installed at the top of the side wall of the humidifying chamber 124, and the wiping roller 7 rolls with the attachment belt 31. At the same time, the surface of the wiping roller 7 is a sponge layer structure. After the atomizing nozzle 6 humidifies the surface of the attachment belt 31, when the attachment belt 31 moves out of the humidifying chamber 124, it can fully contact with the attachment belt 31, and with the help of the wiping roller 7, excess water on the surface of the attachment belt 31 can be scraped off and absorbed to ensure that there is no excessive water on the surface of the attachment belt 31.

[0041] At the same time, in the method of adjusting the adsorption effect based on the above-mentioned control of humidity, in order to ensure the subsequent sufficient separation of the powder material, the present embodiment also provides the following technical solutions. Specifically, an air heater 123 is installed in the gas equalization bin 121, and the air heater 123 is used to preheat the gas blown out of the air nozzle 5. Then, while the air nozzle 5 is blowing, the surface of the blanking area of ​​the attachment belt 31 can also be heated to accelerate the evaporation of water and improve the blanking efficiency. Corresponding heating equipment can also be arranged on the inner lining of the attachment belt 31 to preheat the attachment belt 31 before it reaches the blanking area to mix the powder materials with each other.

[0042] Since the air nozzle 5 continuously outputs gas in the pre-mixing bin 12, in order to ensure the internal air pressure balance of the equipment and prevent excessive air from overflowing from the main upper hopper 21 and the auxiliary upper hopper 22, the present embodiment also provides the following method, wherein a filtering exhaust pipe 125 is provided in the pre-mixing bin 12, and the filtering exhaust pipe 125 is connected to the fan structure connected to the fan pipe 122, wherein the fan pipe 122 is connected to the output end of the fan structure, and the filtering exhaust pipe 125 is connected to the input end of the fan structure, and a filter for filtering powder is provided on the filtering exhaust pipe 125, thereby realizing internal circulation of air and avoiding overflow of powder.

[0043] Furthermore, in order to improve the bonding effect between the powder material and the attachment belt 31, the present embodiment further improves the feeder 2. For details, refer to the attached manual. Figure 8 After adding the corresponding powder materials into the main upper hopper 21 and the auxiliary upper hopper 22, a plurality of grinding balls 24 are put into the main upper hopper 21 and the auxiliary upper hopper 22. The grinding balls 24 sink under the action of their own weight and gather at the main extension tube 211 and the auxiliary extension tube 221. At the same time, a support pad 34 is provided on the inner side of the attachment belt 31. The support pad 34 is in sliding contact with the inner wall of the attachment belt 31, thereby providing a straight and stable support for the attachment belt 31. As the attachment belt 31 moves, the corresponding grinding balls 24 will also roll and move accordingly. On the one hand, the powder materials close to the attachment belt 31 can be pre-stirred and dispersed. On the other hand, the continuous movement and extrusion of the grinding balls 24 that form a flat surface can increase the adhesion strength between the powder materials and the attachment belt 31, thereby improving the fusion effect between different layers of powder materials.

[0044] At the same time, after adding the grinding balls 24, a covering bag 25 can be placed in both the main upper hopper 21 and the auxiliary upper hopper 22. The covering bag 25 is filled with multiple groups of metal particles, so that the covering bag 25 can be spread flat on top of the corresponding powder material, so as to form a relative seal for the powder material and apply pressure to the powder material to further increase the adhesion effect between the powder material and the adhesion belt 31.

[0045] It should be noted that the corresponding proportional relationship between the above-mentioned graphene powder material and other auxiliary powder materials can be pre-set according to needs, and the corresponding amount of powder material can be put into the corresponding main upper hopper 21 and the auxiliary upper hopper 22, and then the mixing condition between the powders can be adjusted by controlling the speed at which the main extension tube 211 and the auxiliary extension tube 221 output the powder. For example, the relative ratio of the outlet size of the auxiliary extension tube 221 and the main extension tube 211 can be adjusted, or the thickness of the output gap between the main extension tube 211 and the auxiliary extension tube 221 can be adjusted to adjust the pre-mixing ratio. For the fixed-ratio mixing step of continuous production, the fixed size of the main extension tube 211 and the auxiliary extension tube 221 and the size of the corresponding output gap can be pre-set without adjustment. However, for equipment producing different products, corresponding adjustments are required. The adjustment method may include adjusting the thickness of the corresponding output gap and controlling the number of auxiliary upper hoppers 22 of the same type (that is, repeatedly adding the same auxiliary powder material to increase the number of layers and thickness ratio). Among them, this embodiment provides a method for adjusting the output gap, refer to the attached manual. Figure 8 and Fig. 9 The flattening guide plates 23 in the main extension tube 211 and the secondary extension tube 221 are both movably installed. For example, the flattening guide plate 23 in the main extension tube 211 is slidably installed in the main extension tube 211, and the flattening guide plate 23 in the secondary extension tube 221 is slidably installed in the secondary extension tube 221. The main extension tube 211 and the secondary extension tube 221 are both provided with a distance regulator 26 for controlling the movement of the flattening guide plate 23, wherein the sliding direction of the flattening guide plate 23 is parallel to the conveying direction of the conveying area of ​​the attachment belt 31. Regarding the tilt setting (since the output gap is not large, even if the height is adjusted, it will not be too large, so the above-mentioned tilt angle is relatively small and close to parallel, so it is difficult to see in the attached figure), the beam pressing roller 36 in this embodiment can adopt a threaded rod structure, and can also be controlled by other linear drive devices. Before actual use, according to the proportion requirements of each powder material, the position of the corresponding flat pressing guide plate 23 is adjusted, and the cross-sectional size and the output gap size of the corresponding main extension tube 211 or the auxiliary extension tube 221 can be adjusted to adapt to the corresponding proportion.

[0046] It should be noted that, in this embodiment, the powder materials are pre-mixed only by the layered mixing component 3 to avoid the agglomeration of the graphene powder before the final mixing. After the pre-mixing, secondary mixing is required with the help of the stirring component 4. Therefore, there is no need to provide too high precision for the proportion problem at the layered mixing component 3. It is only necessary to ensure that all the powder materials can finally enter the stirring chamber 11. The stirring component 4 includes a stirring shaft 41 and a stirring blade 42. The stirring shaft 41 is rotatably installed in the stirring chamber 11 and is driven to rotate by a drive motor arranged outside the stirring chamber 11, and the stirring blade 42 is fixedly installed on the stirring shaft 41, so as to effectively perform secondary mixing.

[0047] For further information, please refer to the attached manual. Fig.10 and Fig.11 The present embodiment also provides a detailed composition scheme of the attachment belt 31. Specifically, the attachment belt 31 includes a base belt 311 and a thin-walled elastic belt 313. The base belt 311 is located in the inner circle. The base belt 311 is provided with a plurality of groups of filling strips 312 corresponding to the thin-walled elastic belt 313 (by cutting a plurality of groups of slits in parallel on the surface of the integrated base belt 311, a plurality of filling strips 312 connected to the base belt 311 can be formed). The elastic coefficient of the thin-walled elastic belt 313 is greater than the elastic coefficient of the base belt 311, that is, the elastic deformation ability of the thin-walled elastic belt 313 is higher. When the attachment belt 31 does not contact the belt roller 32, the corresponding base belt 31 1 and the filling strips 312 are in a straight state, and the filling strips 312 are close to each other, forming an effective support for the thin-walled elastic belt 313. At this time, the surface of the base belt 311 is in an initially contracted straight state, and when the attachment belt 31 gradually approaches the belt roller 32 in the blanking area, due to the formation of an arc area, the diameter of the attachment belt 31 gradually increases from the inside to the outside, so the outermost thin-walled elastic belt 313 is stretched, and the corresponding filling strips 312 are in a mutually open state, so that the powder material previously spread on the surface of the attachment belt 31 can be better separated from the thin-walled elastic belt 313 when the thin-walled elastic belt 313 is stretched, thereby improving the blanking effect.

[0048] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing a graphene powder material, characterized in that: The graphene powder and the auxiliary powder are mixed using a secondary mixing device, including the following steps: Step 1: putting graphene powder into the main upper hopper (21), so that the powder material in the main upper hopper (21) contacts the attachment belt (31) through the main extension tube (211), and then driving the attachment belt (31) to move, so that excess graphene powder is blocked in the main extension tube (211) through the output gap of the main extension tube (211), and the graphene powder layer attached to the attachment belt (31) is output; Step 2: After the graphene powder layer reaches the bottom of the secondary extension tube (221), the auxiliary powder is put into the secondary upper hopper (22), so that the auxiliary powder in the secondary upper hopper (22) contacts the graphene powder layer already formed on the attachment belt (31) through the secondary extension tube (221), and the attachment belt (31) is continuously driven to be transported, so that excess auxiliary powder is blocked in the secondary extension tube (221) through the output gap of the secondary extension tube (221), and the auxiliary powder layer attached to the graphene powder layer on the attachment belt (31) is output; Step 3: Control the attachment belt (31) to continuously move, so that the graphene powder layer and the auxiliary powder layer superimposed thereon are transported backward together, until they are transported to the material drop area, and the graphene powder material and the auxiliary powder material are separated from the attachment belt (31) and fall down; Step 4: The powder material separated from the attachment belt (31) falls into the mixing bin (11) for collection. After all the materials in the main upper hopper (21) and the auxiliary upper hopper (22) have been discharged, the mixing component (4) is started to perform secondary mixing on the pre-mixed powder material in the mixing bin (11); Step 5: Close the stirring assembly (4), open the closed door at the bottom discharge port of the stirring bin (11), and take out the mixed powder material.

2. A method for preparing graphene powder material according to claim 1, characterized in that: The secondary mixing device comprises a mixer (1) and a loader (2), wherein the mixer (1) comprises a stirring chamber (11) and a pre-mixing chamber (12), wherein the pre-mixing chamber (12) is arranged on the stirring chamber (11), and the loader (2) comprises a main hopper (21) and a secondary hopper (22), wherein the main hopper (21) and the secondary hopper (22) are both installed on the pre-mixing chamber (12), wherein a stirring assembly (4) is arranged in the stirring chamber (11), and a layered mixing assembly (3) is arranged in the pre-mixing chamber (12), wherein the layered mixing assembly (3) comprises an attachment belt (31) and a belt roller (32), wherein the attachment belt (31) is a belt-type annular structure, wherein the attachment belt (31) is made of rubber, and wherein at least two groups of belt rollers (32) are arranged, wherein the belt rollers (32) support the attachment belt (31) to form a conveying structure, wherein a conveying structure is formed above the attachment belt (31). The conveying end of the conveying area of ​​the attachment belt (31) forms a material dropping area, and the bottom of the main upper hopper (21) is provided with a main extension tube (211), and the bottom of the auxiliary upper hopper (22) is provided with an auxiliary extension tube (221). The bottom ports of the main extension tube (211) and the auxiliary extension tube (221) are both arranged corresponding to the conveying area of ​​the attachment belt (31). The areas corresponding to the attachment belt (31) on both sides of the main extension tube (211) and the areas corresponding to the attachment belt (31) are respectively formed with input gaps and output gaps, and the input gaps and the output gaps are arranged in sequence along the moving conveying direction of the attachment belt (31). Along the conveying direction of the attachment belt (31), the output gaps of the main extension tube (211) and the auxiliary extension tube (221) are arranged to increase in sequence, and the output gaps of the main extension tube (211) and the auxiliary extension tube (221) are both arranged with flattening guide plates (23) at the output gaps.

3. A method for preparing graphene powder material according to claim 2, characterized in that: An air nozzle (5) is arranged outside the blanking area of ​​the attachment belt (31), and a plurality of groups of the air nozzles (5) are arranged. An air equalization bin (121) is arranged in the pre-mixing bin (12), and a fan duct (122) is connected to the air equalization bin (121), and the fan duct (122) is connected to a fan structure, so that the air nozzle (5) blows air downwards through the fan structure and blows air toward the arc surface at the matching position between the attachment belt (31) and the belt roller (32) in the blanking area, so as to blow away the powder material on the attachment belt (31).

4. A method for preparing graphene powder material according to claim 3, characterized in that: A cleaning brush (33) is provided below the material dropping area of ​​the attachment belt (31), and the bristles of the cleaning brush (33) are in contact with the attachment belt (31). When the attachment belt (31) moves, the cleaning brush (33) is used to clean the residual powder material on the surface of the attachment belt (31). A vibration seat (35) is also provided in the pre-mixing bin (12). The vibration seat (35) is installed in the pre-mixing bin (12) via an elastic member. A vibrator is fixedly installed on the vibration seat (35). A vibration roller is rotatably installed on the vibration seat (35). The vibration roller is in contact with a position of the attachment belt (31) away from the conveying area, and the corresponding area of ​​the attachment belt (31) is driven to vibrate through the vibration seat (35) to shake the residual powder material on the surface of the attachment belt (31) downward.

5. A method for preparing graphene powder material according to claim 4, characterized in that: A humidifying chamber (124) is provided in the area below the attachment belt (31), and an atomizing nozzle (6) is provided in the humidifying chamber (124). When the attachment belt (31) passes through the humidifying chamber (124), the humidity of the surface of the attachment belt (31) is increased by the atomizing nozzle (6). An air heater (123) is installed in the gas equalizing chamber (121), and the gas before being blown out by the gas nozzle (5) is heated by the air heater (123). A filtering exhaust pipe (125) is provided in the pre-mixing chamber (12), and the filtering exhaust pipe (125) is connected to a fan structure connected to the fan pipe (122).

6. A method for preparing graphene powder material according to claim 5, characterized in that: A wiping roller (7) is provided at a position where the side wall of the humidifying chamber (124) cooperates with the attachment belt (31); the wiping roller (7) is rotatably mounted on the top of the side wall of the humidifying chamber (124); the surface of the wiping roller (7) is a sponge layer structure; and excess moisture on the surface of the attachment belt (31) is scraped off and absorbed through the rolling cooperation between the wiping roller (7) and the attachment belt (31).

7. A method for preparing graphene powder material according to claim 6, characterized in that: In the step 1 and the step 2, after the corresponding powder material is added to the main upper hopper (21) and the auxiliary upper hopper (22), a plurality of grinding balls (24) are added to the main upper hopper (21) and the auxiliary upper hopper (22), so that the grinding balls (24) sink under the action of their own weight and gather at the main extension tube (211) and the auxiliary extension tube (221). A support pad (34) is provided on the inner side of the attachment belt (31). The movement of the attachment belt (31) cooperates with the corresponding grinding balls (24) to cause the grinding balls (24) to roll and move accordingly, thereby stirring and squeezing the corresponding powder material downward.

8. A method for preparing graphene powder material according to claim 7, characterized in that: After the grinding balls (24) are added, a covering bag (25) is placed in both the main upper hopper (21) and the auxiliary upper hopper (22), wherein the covering bag (25) is filled with a plurality of groups of metal particles so that the covering bag (25) is laid flat on the corresponding powder material.

9. A method for preparing graphene powder material according to claim 8, characterized in that: The flattening guide plate (23) in the main extension tube (211) is slidably installed in the main extension tube (211), and the flattening guide plate (23) in the secondary extension tube (221) is slidably installed in the secondary extension tube (221), and both the main extension tube (211) and the secondary extension tube (221) are provided with a distance regulator (26) for controlling the movement of the flattening guide plate (23), wherein the sliding direction of the flattening guide plate (23) is inclined relative to the conveying direction of the conveying area of ​​the attachment belt (31), and the position of the corresponding flattening guide plate (23) is controlled by the distance regulator (26) to adjust the cross-sectional size and output gap size of the corresponding main extension tube (211) or secondary extension tube (221).

10. A method for preparing graphene powder material according to claim 9, characterized in that: The attachment belt (31) comprises a base belt (311) and a thin-walled elastic belt (313); the base belt (311) is located in the inner circle; a plurality of groups of filling strips (312) are arranged at positions of the base belt (311) corresponding to the thin-walled elastic belt (313); the elastic coefficient of the thin-walled elastic belt (313) is greater than the elastic coefficient of the base belt (311); when the attachment belt (31) moves to the belt roller (32) in the blanking area, an arc area is formed, and the thin-walled elastic belt (313) is stretched.

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