Graphite purification device and purification method

Abstract

The present invention is a graphite purification device and purification method, the graphite purification device comprises: a furnace body, including a drying zone structure, a low-temperature reaction zone structure, a high-temperature purification zone structure and a cooling zone structure; the low-temperature reaction zone structure can be connected to an air intake pipeline, a return pipeline and a first exhaust pipeline; the high-temperature purification zone structure can be connected to a first protective gas pipeline and a second exhaust pipeline, and the cooling zone structure can be connected to a second protective gas pipeline and a third exhaust pipeline; between the drying zone structure and the low-temperature reaction zone structure, between the low-temperature reaction zone structure and the high-temperature purification zone structure, and between the high-temperature purification zone structure and the cooling zone structure, there are door structures that can be opened and closed; a transmission mechanism, including four transmission devices. The present invention can realize continuous production, has high working efficiency, can effectively improve the graphite purification effect, and has low energy consumption.

Description

Technical Field

[0001] The invention relates to the field of graphite purification, and in particular to a graphite purification device and a purification method. Background Art

[0002] Due to its excellent physical and chemical properties, graphite is widely used in many fields such as electronics, chemical industry, aerospace, etc. However, natural graphite or some artificial graphite often contains a variety of impurities, which will seriously affect the performance and quality of graphite and limit its application in high-end fields. Therefore, it is particularly important to effectively purify graphite.

[0003] Traditional graphite purification methods and devices have many shortcomings. For example, some devices cannot achieve continuous production, resulting in low production efficiency; some devices do not handle tail gas generated at different stages perfectly, which easily causes environmental pollution; some devices cannot accurately control key parameters such as temperature and gas atmosphere in each reaction area during the purification process, resulting in unsatisfactory purification effects. In view of this, it is necessary to develop a new graphite purification device and corresponding purification method to overcome the defects in the prior art and improve the efficiency, effect and environmental protection of graphite purification. Summary of the invention

[0004] The object of the present invention is to provide a graphite purification device and a purification method, which can realize continuous production, have high working efficiency, can effectively improve the graphite purification effect, and have low energy consumption.

[0005] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0006] The present invention provides a graphite purification device, comprising:

[0007] The furnace body comprises a drying zone structure, a low-temperature reaction zone structure, a high-temperature purification zone structure and a cooling zone structure which are sequentially arranged from the head to the tail; the low-temperature reaction zone structure is connected with an air inlet pipeline, a return pipeline and a first exhaust pipeline in a switchable manner, and the return pipeline can return the unreacted reaction gas to the low-temperature reaction zone structure; the high-temperature purification zone structure is connected with a first protective gas pipeline and a second exhaust pipeline in a switchable manner, and the cooling zone structure is connected with a second protective gas pipeline and a third exhaust pipeline in a switchable manner; a door structure which can be opened and closed is arranged between the drying zone structure and the low-temperature reaction zone structure, between the low-temperature reaction zone structure and the high-temperature purification zone structure, and between the high-temperature purification zone structure and the cooling zone structure;

[0008] The transmission mechanism includes four transmission devices, which are used to push the material holding device containing the graphite powder to be purified from the drying area structure into the low-temperature reaction area structure, from the low-temperature reaction area structure into the high-temperature purification area structure, from the high-temperature purification area structure into the cooling area structure, and push it out from the cooling area structure.

[0009] In a preferred embodiment of the present invention, the temperature in the low-temperature reaction zone structure is 800-1000°C, and the temperature in the high-temperature purification zone structure is 1500-1800°C.

[0010] In a preferred embodiment of the present invention, the material holding device includes a push plate and a plurality of crucibles placed on the push plate, and the crucibles are used to hold graphite powder; one or a plurality of push plates arranged closely together can be placed in the drying zone structure, the low-temperature reaction zone structure, the high-temperature purification zone structure and the cooling zone structure along their respective material conveying directions.

[0011] In a preferred embodiment of the present invention, the transmission device is a push rod structure, and the drying zone structure, the low-temperature reaction zone structure, the high-temperature purification zone structure and the cooling zone structure are all rectangular parallelepiped structures.

[0012] In a preferred embodiment of the present invention, the tail of the drying zone structure is connected to the head side wall of the low-temperature reaction zone structure, the low-temperature reaction zone structure and the cooling zone structure are both located on the same side of the high-temperature purification zone structure, and the tail of the low-temperature reaction zone structure and the head of the cooling zone structure are respectively connected to the head side wall and the tail side wall of the high-temperature purification zone structure.

[0013] In a preferred embodiment of the present invention, a first empty position is provided in the drying zone structure near its head, a second empty position is provided in the low-temperature reaction zone structure near its head, and a third empty position and a fourth empty position are provided at the head and tail of the high-temperature purification zone structure, respectively; the four transmission devices can respectively push the push plate located in the first empty position to push the corresponding push plate near the tail of the drying zone structure into the second empty position, push the push plate located in the second empty position to push the corresponding push plate near the tail of the low-temperature reaction zone structure into the third empty position, push the push plate located in the third empty position to push the corresponding push plate near the fourth empty position into the fourth empty position, and push the push plate located in the fourth empty position to push out the corresponding push plate near the tail of the cooling zone structure.

[0014] In a preferred embodiment of the present invention, a heating device is provided on the drying zone structure, and the drying temperature in the drying zone structure is less than or equal to 300°C.

[0015] In a preferred embodiment of the present invention, a first air inlet and a second air inlet are provided at the head of the low-temperature reaction zone structure, and a first exhaust port is provided at the tail thereof, an air inlet pipeline is connected to the first air inlet, the second air inlet is connected to the first end of the return pipeline and the first end of the first exhaust pipeline in a switchable manner, and the second end of the return pipeline is connected to the second air inlet.

[0016] In a preferred embodiment of the present invention, a condensing device and an adsorption device are provided on the return pipeline.

[0017] In a preferred embodiment of the present invention, a third air inlet and a second exhaust port are respectively provided at the head and top of the high-temperature purification zone structure, and are respectively connected to the first protective gas pipeline and the second exhaust pipeline; a circulating water cooling device is provided on the cooling zone structure, and a fourth air inlet and a third exhaust port are respectively provided at the head and tail of the cooling zone structure, and are respectively connected to the second protective gas pipeline and the third exhaust pipeline.

[0018] In a preferred embodiment of the present invention, vacuum pumps are provided on the first exhaust pipeline, the second exhaust pipeline and the third exhaust pipeline, and the vacuum pumps are also connected to an exhaust gas treatment device.

[0019] In a preferred embodiment of the present invention, the tail gas treatment device comprises a filtering device, a desulfurization and denitrification device and an alkaline solution spraying device which are sequentially connected in series along the air flow direction.

[0020] In a preferred embodiment of the present invention, the tail of the cooling zone structure is an open end, and a nozzle assembly and a gas supply pipeline are provided at the tail of the cooling zone structure. The nozzle assembly is arranged at the top of the cooling zone structure, and the gas supply pipeline is connected to the nozzle assembly to form an air curtain at the open end.

[0021] In a preferred embodiment of the present invention, the graphite purification device further comprises a control device, and the control device is electrically connected to the door structure and the transmission device.

[0022] The present invention also provides a graphite purification method, which uses the above-mentioned graphite purification device for processing. The graphite purification method comprises:

[0023] Place the material receiving device filled with graphite powder to be purified into the drying zone structure to remove moisture from the graphite powder;

[0024] Pushing the dried graphite powder containing material device into the low temperature reaction zone structure, introducing a mixed gas of reaction gas and protective gas into the low temperature reaction zone structure, so that the solid impurities in the graphite powder react with the reaction gas to generate halide impurities, and returning the unreacted reaction gas to the low temperature reaction zone structure;

[0025] Pushing the material receiving device containing the graphite powder after the reaction is completed into the high-temperature purification zone structure to gasify the halide impurities in the graphite powder;

[0026] The gasified graphite powder containing device is pushed into the cooling zone structure to cool the graphite powder to obtain a purified graphite powder product.

[0027] As described above, the graphite purification device and purification method of the present invention utilize multiple door structures to divide the furnace body into four relatively independent drying zone structures, low-temperature reaction zone structures, high-temperature purification zone structures, and cooling zone structures, and utilize a transmission mechanism to drive the corresponding material holding device to realize the transfer of graphite powder between various zones, which can realize continuous graphite purification operation and improve efficiency. At the same time, it is convenient to accurately control the environmental parameters of each zone, so as to perform water removal, impurity reaction, impurity gasification, cooling and other operations under different temperatures and gas atmospheres, which is more conducive to obtaining high-purity graphite powder. At the same time, utilizing the characteristics that the reaction temperature of solid impurities in graphite powder is low and the volatilization temperature of the generated halide impurities is high, a relatively independent low-temperature reaction zone structure and a high-temperature purification zone structure are set, so that the impurity reaction and halide impurity gasification in graphite powder are completed in two zones respectively, which can effectively reduce energy consumption and facilitate the recovery of reaction gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following drawings are intended only to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0029] Figure 1 This is a schematic structural diagram of a graphite purification device provided by the present invention.

[0030] Figure 2 A schematic diagram of a graphite purification device provided by the present invention.

[0031] Figure 3 This is a schematic structural diagram of the cooling zone structure provided by the present invention.

[0032] Description of Figure Numbers:

[0033] 1. Drying area structure;

[0034] 2. Low temperature reaction zone structure; 21. Intake pipeline; 22. Exhaust main pipe; 23. Return pipeline; 231. First valve; 232. Condensation device; 233. Adsorption device; 24. First exhaust pipeline; 241. Second valve;

[0035] 3. High temperature purification area structure; 31. First protective gas pipeline; 32. Second exhaust pipeline;

[0036] 4. Cooling zone structure; 41. Second protective gas pipeline; 42. Third exhaust pipeline; 43. Circulating water cooling device; 44. Nozzle assembly; 45. Gas supply pipeline;

[0037] 5. Material holding device; 51. Push plate; 52. Crucible;

[0038] 61. First door structure; 62. Second door structure; 63. Third door structure;

[0039] 71. First transmission device; 72. Second transmission device; 73. Third transmission device; 74. Fourth transmission device;

[0040] 81, first vacancy; 82, second vacancy; 83, third vacancy; 84, fourth vacancy. DETAILED DESCRIPTION

[0041] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0042] like Figures 1 to 3 As shown, the present application provides a graphite purification device, comprising:

[0043] The furnace body comprises a drying zone structure 1, a low-temperature reaction zone structure 2, a high-temperature purification zone structure 3 and a cooling zone structure 4 which are sequentially arranged from the head to the tail; the low-temperature reaction zone structure 2 is connected with an inlet pipeline 21, a return pipeline 23 and a first exhaust pipeline 24, and the return pipeline 23 can return the unreacted reaction gas to the low-temperature reaction zone structure 2; the high-temperature purification zone structure 3 is connected with a first protective gas pipeline 31 and a second exhaust pipeline 32, and the cooling zone structure 4 is connected with a second protective gas pipeline 41 and a third exhaust pipeline 42; between the drying zone structure 1 and the low-temperature reaction zone structure 2, between the low-temperature reaction zone structure 2 and the high-temperature purification zone structure 3, and between the high-temperature purification zone structure 3 and the cooling zone structure 4, there are door structures which can be opened and closed (respectively recorded as the first door structure 61, the second door structure 62 and the third door structure 63 in this embodiment);

[0044] The transmission mechanism includes four transmission devices (respectively recorded as the first transmission device 71, the second transmission device 72, the third transmission device 73 and the fourth transmission device 74 in this embodiment), which are used to push the material holding device 5 containing the graphite powder to be purified from the drying area structure 1 into the low-temperature reaction area structure 2, from the low-temperature reaction area structure 2 into the high-temperature purification area structure 3, from the high-temperature purification area structure 3 into the cooling area structure 4, and push it out from the cooling area structure 4.

[0045] During operation, the pushing and transfer of the material holding device 5 filled with graphite powder between the drying zone structure 1, the low-temperature reaction zone structure 2, the high-temperature purification zone structure 3 and the cooling zone structure 4 is achieved by the door structures cooperating with the transmission devices.

[0046] The drying zone structure 1 is mainly used to dry the graphite powder and remove the moisture therein. The low-temperature reaction zone structure 2 is a low-temperature environment. A mixed gas of reaction gas and protective gas can be introduced through the air inlet pipe 21. The reaction gas generally uses a chlorine-containing or fluorine-containing gas to react with solid impurities (such as aluminum oxide, silicon dioxide, etc.) in the graphite powder to remove these solid impurities. Under normal circumstances, the first exhaust pipe 24 remains closed, and the return pipe 23 is always connected to the tail and head of the low-temperature reaction zone structure 2 to pass the unreacted reaction gas into the low-temperature reaction zone structure 2 to continue the reaction for recycling; when the furnace needs to be stopped, the air inlet pipe 21 and the return pipe 23 are closed again, and the first exhaust pipe 24 is opened to exhaust the gas in the low-temperature reaction zone structure 2. The high-temperature reaction zone structure is a high-temperature environment. The halide impurities generated in the low-temperature reaction zone at this high temperature will volatilize at high temperature, and the halide impurities in the graphite powder will be gasified and discharged through the second exhaust pipe 32. The cooling zone structure 4 is used to cool the graphite powder to obtain high-purity graphite powder.

[0047] Therefore, the graphite purification device in this embodiment uses multiple door structures to divide the furnace body into four relatively independent drying area structure 1, low temperature reaction area structure 2, high temperature purification area structure 3 and cooling area structure 4, and uses a transmission mechanism to push the corresponding material holding device 5 to realize the transfer of graphite powder between various areas, which can realize continuous graphite purification operation and improve efficiency. At the same time, it is convenient to accurately control the environmental parameters of each area, so as to perform water removal, impurity reaction, impurity gasification, cooling and other operations under different temperatures and gas atmospheres, which is more conducive to obtaining high-purity graphite powder. At the same time, taking advantage of the low reaction temperature of solid impurities in graphite powder and the high volatilization temperature of generated halide impurities, relatively independent low temperature reaction area structure 2 and high temperature purification area structure 3 are set to complete the impurity reaction and halide impurity gasification in graphite powder in two areas respectively, which can effectively reduce energy consumption and facilitate the recovery of reaction gas.

[0048] In this embodiment, the temperature in the low temperature reaction zone structure 2 is 800-1000°C, at which temperature the solid impurities in the graphite powder react with the reaction gas. The temperature in the high temperature purification zone structure 3 is 1500-1800°C, at which temperature the halide impurities generated after the reaction in the low temperature reaction zone structure 2 will be gasified at high temperature, and the original solid impurities in the graphite powder will no longer react at this high temperature, so there is no need to introduce reaction gas in this area, only protective gas is needed.

[0049] Furthermore, the material holding device 5 includes a push plate 51 and a plurality of crucibles 52 placed on the push plate 51, and the crucible 52 is used to hold graphite powder; one or a plurality of push plates 51 arranged closely together can be placed in the drying area structure 1, the low-temperature reaction area structure 2, the high-temperature purification area structure 3 and the cooling area structure 4 along their respective material conveying directions.

[0050] The push plate 51 generally adopts a rectangular plate body. One push plate 51 and multiple crucibles 52 placed thereon are used as a set of material holding devices 5. When working, at least one set of material holding devices 5 can be placed in each area. Generally, after continuous working, multiple sets of material holding devices 5 will be placed in each area. Multiple push plates 51 in multiple sets of material holding devices 5 in each area are closely adjacent and arranged in sequence. When it is necessary to transfer the material holding device 5 filled with graphite powder to the next area, the corresponding door structure is opened and the corresponding push plate 51 is pushed by the corresponding transmission device.

[0051] More specifically, the transmission device is a push rod structure, and the drying zone structure 1, the low temperature reaction zone structure 2, the high temperature purification zone structure 3 and the cooling zone structure 4 are all rectangular parallelepiped structures. The push rod structure can be, for example, a hydraulic push rod, that is, a hydraulic cylinder. The cylinder body of the hydraulic cylinder is connected to the corresponding wall surface of the furnace body, and the push rod of the hydraulic cylinder can be extended and retracted to push the corresponding push plate 51. The length direction of the push rod should be parallel to the conveying direction of the graphite powder in the corresponding area, that is, parallel to the length direction of the corresponding rectangular parallelepiped structure.

[0052] In order to facilitate processing and installation and reduce floor space, refer to Figure 1 and Figure 2 The tail of the drying zone structure 1 is connected to the head side wall of the low-temperature reaction zone structure 2, the low-temperature reaction zone structure 2 and the cooling zone structure 4 are both located on the same side of the high-temperature purification zone structure 3, and the tail of the low-temperature reaction zone structure 2 and the head of the cooling zone structure 4 are respectively connected to the head side wall and the tail side wall of the high-temperature purification zone structure 3.

[0053] In order to facilitate the transfer of each material holding device 5 in each area, a first empty position 81 is provided near the head of the drying zone structure 1, a second empty position 82 is provided near the head of the low-temperature reaction zone structure 2, and a third empty position 83 and a fourth empty position 84 are provided at the head and tail of the high-temperature purification zone structure 3. The four transmission devices can respectively push the push plate 51 located at the first empty position 81 to push the corresponding push plate 51 near the tail of the drying zone structure 1 into the second empty position 82, push the push plate 51 located at the second empty position 82 to push the corresponding push plate 51 near the tail of the low-temperature reaction zone structure 2 into the third empty position 83, push the push plate 51 located at the third empty position 83 to push the corresponding push plate 51 near the fourth empty position 84 into the fourth empty position 84, and push the push plate 51 located in the fourth empty position 84 to push out the corresponding push plate 51 near the tail of the cooling zone structure 4.

[0054] Since the drying temperature in the drying area structure 1 is lower than 400°C, the graphite powder will not be oxidized, so there is no need to introduce protective gas into the drying area structure 1. The drying area structure 1 can be connected to the outside atmosphere or a closed structure can be adopted. Therefore, the head of the drying area structure 1 can be an open end or a door structure can be provided.

[0055] When the head of the drying zone structure 1 is an open end, a corresponding support frame can be arranged outside the open end to fix the cylinder of the first transmission device 71. When the material receiving device 5 containing the graphite powder to be purified is placed in the first empty space 81, it can be completed by using a corresponding auxiliary machine (such as a manipulator); then the push rod of the first transmission device 71 extends to push the material receiving device 5 in the first empty space 81, so that the material receiving device 5 near the tail of the drying zone structure 1 can be pushed into the second empty space 82 of the low-temperature reaction zone structure 2. At this time, the first empty space 81 is vacant again, so that the material receiving device 5 can be placed in the first empty space 81 next time. When the head of the drying zone structure 1 is provided with a door structure, the cylinder of the first transmission device 71 can be arranged on the door structure. When it is necessary to place the material receiving device 5 containing the graphite powder to be purified in the first empty space 81, the door structure is opened first, and then the corresponding auxiliary machine is used to complete it.

[0056] The second transmission device 72 is arranged on the end face of the head of the low-temperature reaction zone structure 2. The push rod of the second transmission device 72 extends to push the material receiving device 5 located in the second empty position 82, and then pushes the multiple material receiving devices 5 that are adjacent in sequence together, and then pushes the material receiving device 5 near the tail of the low-temperature reaction zone structure 2 into the third empty position 83 of the high-temperature purification zone structure 3. At this time, the second empty position 82 is vacant again to receive the material receiving device 5 sent from the drying zone structure 1 next time. The third transmission device 73 is arranged on the end face of the head of the high-temperature purification zone structure 3, and the fourth transmission device 74 is arranged on the side wall of the tail of the high-temperature purification zone structure 3 that is away from the cooling zone structure 4. The push rod of the third transmission device 73 extends to push the material receiving device 5 located in the third empty position 83, and pushes the multiple material receiving devices 5 that are adjacent in sequence in the high-temperature purification zone structure 3, so that the material receiving device 5 near the fourth empty position 84 can be pushed into the fourth empty position 84. At this time, the third empty position 83 is vacant again to receive the material receiving device 5 sent from the low-temperature reaction zone structure 2. The push rod of the fourth transmission device 74 extends out to push the material receiving device 5 located at the fourth empty position 84, and pushes multiple material receiving devices 5 adjacent to each other in the cooling zone structure 4 in sequence, so that the material receiving device 5 located at the tail of the cooling zone structure 4 can be pushed out. At this time, the fourth empty position 84 is vacated again to receive the next material receiving device 5 pushed in.

[0057] In this way, the entire graphite purification device forms a multi-stage continuous push boat. Through the cooperation of various door structures, various transmission devices and multiple groups of material holding devices 5 that can be placed closely in each area, continuous processing operation of graphite powder can be realized, which greatly improves work efficiency. Moreover, each area is relatively independent and can operate independently without being affected by the atmosphere and temperature of different areas. The environment of each area can be accurately controlled, effectively ensuring the effect and quality of graphite purification.

[0058] In an optional embodiment, the tail of the high temperature purification zone structure 3 can also be connected to the head side wall of the cooling zone structure 4, and the fourth vacancy 84 is provided at the head of the cooling zone structure 4. Accordingly, the fourth transmission device 74 is provided on the head end face of the cooling zone structure 4.

[0059] When working, the actions of the first transmission device 71 and the second transmission device 72 are the same as those of the previous embodiment. In this optional embodiment, the push rod of the third transmission device 73 extends to push the material receiving device 5 located in the third empty position 83, and pushes the multiple material receiving devices 5 that are adjacent in sequence in the high-temperature purification zone structure 3, so that a group of material receiving devices 5 near the tail of the high-temperature purification zone structure 3 can be pushed into the fourth empty position 84, and the third empty position 83 is vacant again. The push rod of the fourth transmission device 74 extends to push the material receiving device 5 located in the fourth empty position 84, and pushes the multiple material receiving devices 5 that are adjacent in sequence in the cooling zone structure 4, so that the material receiving device 5 located at the tail of the cooling zone structure 4 can be pushed out, and the fourth empty position 84 is vacant again.

[0060] Of course, the specific layout of each area and the setting of each space can be designed according to needs, and this embodiment is only an example.

[0061] Furthermore, a heating device is provided on the drying zone structure 1, and the drying temperature in the drying zone structure 1 is less than or equal to 300° C. The graphite powder is dried by heating. In this embodiment, the maximum heating temperature for drying is 300° C., and the drying temperature in the drying zone structure 1 is preferably 100-200° C.

[0062] A first air inlet and a second air inlet are provided at the head of the low-temperature reaction zone structure 2, and a first exhaust port is provided at the tail thereof. An air inlet pipeline 21 is connected to the first air inlet, and the second air inlet is connected to the first end of the return pipeline 23 and the first end of the first exhaust pipeline 24 in a switchable manner, and the second end of the return pipeline 23 is connected to the second air inlet.

[0063] The first air inlet, the second air inlet and the first exhaust port are all arranged on the top surface of the low-temperature reaction zone structure 2. The air inlet pipeline 21 is used to connect the first air inlet device, and the first air inlet device can simultaneously or separately introduce the reaction gas and the protective gas into the low-temperature reaction zone structure 2. In order to facilitate connection and control, the exhaust main pipe 22 is connected at the first exhaust port, and the exhaust main pipe 22 is connected to the first end of the return pipeline 23 and the first end of the first exhaust pipeline 24, and the three form a three-way pipeline. A first valve 231 is provided on the return pipeline 23 near its first end, and a second valve 241 is provided on the first exhaust pipeline 24 near its first end to control the connection and disconnection of the first exhaust port with the return pipeline 23 and the first exhaust pipeline 24.

[0064] A condensing device 232 and an adsorption device 233 are provided on the return line 23 .

[0065] The condensation device 232 and the adsorption device 233 are located between the first valve 231 and the second air inlet. The condensation device 232 is mainly used to remove gas impurities in the unreacted reaction gas discharged from the first exhaust port, so that the gas impurities are condensed into liquid; the adsorption device 233 can be, for example, a ceramic membrane adsorption device, which is mainly used to adsorb solid impurities in the unreacted reaction gas discharged from the first exhaust port; and then the unreacted reaction gas discharged from the first exhaust port is decontaminated for better recycling.

[0066] A third air inlet and a second air outlet are respectively provided at the head and top of the high-temperature purification zone structure 3, and are connected to the first protective gas pipeline 31 and the second exhaust pipeline 32 respectively.

[0067] The first protective gas pipeline is used to connect the second gas inlet device to introduce protective gas into the high-temperature purification area structure 3. The third gas inlet is arranged on the top surface of the head of the high-temperature purification area structure 3, and the second gas outlet is arranged on the top surface of the high-temperature purification area structure 3, which can be arranged near the top surface of the middle part of the high-temperature purification area structure 3, or near the top surface of the tail part of the high-temperature purification area structure 3, depending on the needs.

[0068] A circulating water cooling device 43 is provided on the cooling zone structure 4 to cool the graphite powder. The circulating water cooling device 43 includes a circulating water pipe arranged in a meandering manner on the cooling zone structure 4. The water inlet and water outlet of the circulating water pipe are connected to the water tank, and a corresponding pumping device is provided to form a circulation. A fourth air inlet and a third air outlet are provided at the head and tail of the cooling zone structure 4, respectively, and are connected to the second protective air pipeline 41 and the third air outlet 42, respectively.

[0069] The fourth air inlet and the third air outlet are both provided on the top surface of the cooling zone structure 4. The second protective gas pipeline 41 can be directly connected to the first protective gas pipeline 31 to share the same second air inlet device with the first protective gas pipeline 31; or, the second protective gas pipeline 41 can also be connected to the third air inlet device to introduce protective gas into the cooling zone structure 4. The protective gas referred to herein is an inert gas, such as nitrogen and argon, to prevent the graphite powder from being oxidized.

[0070] Furthermore, vacuum pumps are provided on the first exhaust pipeline 24, the second exhaust pipeline 32 and the third exhaust pipeline 42. The second valve 241 is located between the first exhaust port and the corresponding vacuum pump. Since the second exhaust pipeline 32 and the third exhaust pipeline 42 are always in an open state when the entire graphite purification device is in operation, the third exhaust pipeline 42 can be connected to the second exhaust pipeline 32, and the two share a vacuum pump (the vacuum pump is provided on the second exhaust pipeline 32); or, the third exhaust pipeline 42 and the second exhaust pipeline 32 can be connected to two vacuum pumps respectively, and then connected to the same tail gas treatment device through corresponding pipelines.

[0071] The tail gas treatment device includes a filter device (such as a ceramic membrane filter device), a desulfurization and denitrification device, and an alkali solution spray device that are sequentially connected in series along the airflow direction. The tail gas treatment device can effectively treat the tail gas and reduce pollution.

[0072] Furthermore, the tail of the cooling zone structure 4 is an open end, so that the operator can observe the timing when the container containing graphite powder is pushed out of the cooling zone structure 4.

[0073] In order to separate the space in the cooling zone structure 4 from the external environment after the tail of the cooling zone structure 4 is designed as an open end to prevent the intrusion of external cold air, dust and other impurities, refer to Figure 3 A nozzle assembly 44 and a gas supply pipeline 45 are provided at the tail of the cooling zone structure 4. The nozzle assembly 44 is arranged at the top of the cooling zone structure 4. The gas supply pipeline 45 is connected to the nozzle assembly 44 to form an air curtain at the open end.

[0074] The gas supply pipeline 45 is used to connect the gas supply device to provide a protective gas with a specific pressure and flow rate. When the cooling zone structure 4 is in operation, the protective gas is evenly and quickly ejected through each nozzle in the nozzle assembly 44, forming a continuous and stable curtain-like gas curtain with a certain pressure and flow rate at the open end of the cooling zone structure 4, which is the above-mentioned gas curtain.

[0075] Furthermore, the graphite purification device also includes a control device, which is electrically connected to the door structure and the transmission device.

[0076] The control device is also electrically connected to the heating device, each air intake device, the first valve 231, the second valve 241, each vacuum pump, the pumping device corresponding to the circulating water cooling device 43 and the gas supply device on the above-mentioned drying area structure 1 to achieve automatic control.

[0077] Furthermore, the present application also provides a graphite purification method, which is processed by the above-mentioned graphite purification device, and the graphite purification method comprises:

[0078] Putting the material holding device 5 filled with graphite powder to be purified into the drying zone structure 1 to remove moisture from the graphite powder;

[0079] Push the dried graphite powder containing device 5 into the low-temperature reaction zone structure 2, and introduce a mixed gas of reaction gas and protective gas into the low-temperature reaction zone structure 2, so that the solid impurities in the graphite powder react with the reaction gas to generate halide impurities, and return the unreacted reaction gas to the low-temperature reaction zone structure 2;

[0080] Pushing the material receiving device 5 containing the graphite powder after the reaction is completed into the high-temperature purification zone structure 3 to gasify the halide impurities in the graphite powder;

[0081] The material receiving device 5 containing the gasified graphite powder is pushed into the cooling zone structure 4 to cool the graphite powder to obtain a purified graphite powder product.

[0082] This method uses the above-mentioned graphite purification device for processing and has the same advantages, which will not be repeated here.

[0083] In order to better understand the above purification method, the method is described below with a specific example, as follows:

[0084] Using flake graphite with a purity of 94.7% as raw material, during operation, a group of material holding devices 5 (a group of material holding devices 5 includes a push plate 51 and a plurality of crucibles 52 filled with graphite powder to be purified) are pushed into the first empty space 81 in the drying zone structure 1 by an auxiliary machine at regular intervals to remove moisture from the material at a drying temperature of 200°C.

[0085] Open the first door structure 61, use the first transmission device 71 to push the material holding device 5 located in the first empty position 81, and then push the dried material holding device 5 located at the tail of the drying zone structure 1 into the low-temperature reaction zone structure 2. After pushing, close the first door structure 61; introduce a mixed process gas of reaction gas and protective gas into the low-temperature reaction zone structure 2, and let the solid impurities in the graphite powder react with the reaction gas at 900°C to generate halides. During the operation of the low-temperature reaction zone structure 2, the first valve 231 is opened and the second valve 241 is closed, so that the unreacted reaction gas re-enters the furnace body to participate in the reaction after the impurities are removed by adsorption and condensation. If the furnace does not need to be stopped, the first valve 231 is always opened and the second valve 241 is always closed; when the furnace needs to be stopped, the first valve 231 is closed and the second valve 241 is opened, the introduction of the mixed process gas is stopped, and the low-temperature reaction zone structure 2 is vacuumed by the corresponding vacuum pump, and the gas in the area is discharged and enters the tail gas treatment device for treatment to prevent pollution.

[0086] The second door structure 62 is opened, and the second transmission device 72 is used to push the material holding device 5 in the second empty position 82, so that a group of material holding devices 5 located at the tail of the low-temperature reaction zone structure 2 that have reacted can be pushed into the high-temperature purification zone structure 3, and the second door structure 62 is closed after pushing in; during the operation of the high-temperature purification zone structure 3, the first protective gas pipeline 31 always passes protective gas into the high-temperature purification zone structure 3, the second exhaust pipeline 32 is always connected to the high-temperature purification zone structure 3, and the corresponding vacuum pump is always working. The material in this area is heated to 1600°C, and the halide impurities are vaporized and pass through the second exhaust pipeline 32. After the impurity gas is fully discharged, the graphite purification process is completed.

[0087] The third transmission device 73 is used to push the material receiving device 5 located at the third empty space 83, and the material receiving device 5 near the fourth empty space 84 is pushed into the fourth empty space 84. The third door structure 63 is opened, and the material receiving device 5 located at the fourth empty space 84 is pushed by the fourth transmission device 74, so that the material receiving device 5 after high-temperature purification can be pushed into the cooling zone structure 4, and the material receiving device 5 near the tail of the cooling zone structure 4 that has been cooled is pushed out, and high-purity graphite powder is obtained after cooling in the cooling zone structure 4. The polluted gas discharged from the exhaust pipe is discharged after being filtered by a ceramic membrane, desulfurized and denitrified, and sprayed with alkali solution. According to the test, the purity of the purified graphite is 99.996%.

[0088] It can be understood that initially, each area of ​​the entire graphite purification device is empty and there is no material holding device 5. After the operation starts, it is only necessary to continuously place a group of material holding devices 5 into the first empty space 81 at a certain time interval, and to make each transmission device push the material holding device 5 in the corresponding empty space at a certain time interval and propulsion speed, so as to ensure that the reaction time of each group of material holding devices 5 in the low-temperature reaction zone structure 2 meets the preset reaction time, and the gasification time in the high-temperature purification zone structure 3 meets the preset gasification time, thereby realizing a multi-stage continuous push-boat processing method to ensure continuous operation. When the furnace is about to be shut down and the last group of material holding devices 5 needs to be continuously pushed out, it is sufficient to continuously place empty push plates 51 (i.e., push plates 51 without crucibles 52 and graphite powder) into the first empty space 81 according to the previous rhythm. In terms of propulsion speed, the propulsion speeds of the first push plate 51 to the last push plate 51 are the same.

[0089] In summary, the graphite purification device and purification method in this embodiment have the following advantages:

[0090] (1) The graphite purification device of this embodiment is a multi-stage continuous push-boat graphite purification device. According to the principle of graphite impurity removal and the characteristics of each temperature zone, a multi-stage continuous structure is designed to realize the step-by-step process of low-temperature reaction and high-temperature purification. It can efficiently remove impurities in graphite and obtain high-quality high-purity graphite powder. At the same time, it can reduce energy consumption, improve energy utilization efficiency, and reduce production costs.

[0091] (2) This embodiment realizes the continuous operation of graphite purification. The entire purification method can efficiently obtain high-purity graphite powder. Compared with the traditional intermittent device, the production efficiency is greatly improved and can meet the needs of large-scale industrial production.

[0092] (3) This embodiment can reduce the amount of reaction gas used and lower production costs by recycling the reaction gas, while greatly reducing the emission of reaction gas that does not participate in the reaction, further reducing pollutant emissions, and improving the economy and environmental protection of the entire device.

[0093] (4) This embodiment adopts a vacuum environment during the high-temperature purification stage (the vacuum environment in this area can be ensured by continuously operating the vacuum pump on the second exhaust line 32). On the one hand, it can reduce the sublimation temperature of pollutants, making it easier for impurities to be gasified and discharged, significantly improving the purification effect; on the other hand, it can quickly discharge pollutants from the furnace body, effectively reducing secondary pollution of pollutants to the product, and further ensuring the purity of graphite.

[0094] (5) Corresponding door structures, gas recovery and tail gas treatment devices are provided between each area, and the transmission device adopts a hydraulic push rod structure and cooperates with the push plate 51 to realize continuous boat pushing. The purification method is to push the push plate 51 with the crucible 52 placed to each area in sequence through the transmission device, and perform water removal, impurity reaction and gasification, tail gas purification and other operations under different temperatures and gas atmospheres, and finally obtain high-purity graphite powder. This embodiment can realize continuous production, improve efficiency, accurately control the purification environment, effectively treat tail gas, improve graphite purification effect and product quality, and has good application prospects.

[0095] The above are only exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A graphite purification device, characterized in that: include: The furnace body comprises a drying zone structure, a low-temperature reaction zone structure, a high-temperature purification zone structure and a cooling zone structure which are sequentially arranged from the head to the tail; the low-temperature reaction zone structure can be connected to an air inlet pipeline, a return pipeline and a first exhaust pipeline in a switchable manner, the air inlet pipeline is used to introduce a mixed gas of a reaction gas and a protective gas, the reaction gas is a chlorine-containing or fluorine-containing gas, the temperature in the low-temperature reaction zone structure is 800-1000° C., the solid impurities in the graphite powder to be purified in the low-temperature reaction zone structure can react with the reaction gas to generate halide impurities, the return pipeline can return the unreacted reaction gas to the low-temperature reaction zone structure; the high-temperature purification zone structure can be connected to a first protective gas pipeline and a second exhaust pipeline in a switchable manner, the first protective gas pipeline is used to introduce a protective gas, the temperature in the high-temperature purification zone structure is 1500-1800° C., the halide impurities in the high-temperature reaction zone structure can be gasified at high temperature and discharged through the second exhaust pipeline; The cooling zone structure is connected to a second protective gas pipeline and a third exhaust pipeline in an on-off manner; a door structure that can be opened and closed is provided between the drying zone structure and the low-temperature reaction zone structure, between the low-temperature reaction zone structure and the high-temperature purification zone structure, and between the high-temperature purification zone structure and the cooling zone structure; A transmission mechanism, including four transmission devices, for driving a material holding device containing graphite powder to be purified to achieve transfer of graphite powder between the drying zone structure, the low-temperature reaction zone structure, the high-temperature purification zone structure and the cooling zone structure; Wherein, the material holding device comprises a push plate and a plurality of crucibles placed on the push plate, and the crucible is used to hold graphite powder; one or a plurality of push plates arranged closely together can be placed in the drying zone structure, the low-temperature reaction zone structure, the high-temperature purification zone structure and the cooling zone structure along the respective material conveying directions; the transmission device is a push rod structure, and the drying zone structure, the low-temperature reaction zone structure, the high-temperature purification zone structure and the cooling zone structure are all rectangular parallelepiped structures; The tail of the drying zone structure is connected to the head side wall of the low-temperature reaction zone structure, the low-temperature reaction zone structure and the cooling zone structure are both located on the same side of the high-temperature purification zone structure, and the tail of the low-temperature reaction zone structure is connected to the head side wall of the high-temperature purification zone structure; a first empty position is provided in the drying zone structure near its head, a second empty position is provided in the low-temperature reaction zone structure near its head, and a third empty position is provided in the head of the high-temperature purification zone structure; wherein the two transmission devices can respectively push the push plate located in the first empty position to push the corresponding push plate near the tail of the drying zone structure into the second empty position, and push the push plate located in the second empty position to push the corresponding push plate near the tail of the low-temperature reaction zone structure into the third empty position; The head of the cooling zone structure is connected to the side wall of the tail of the high-temperature purification zone structure, and a fourth empty space is provided at the tail of the high-temperature purification zone structure. The other two transmission devices can respectively push the push plate located in the third empty space to push the corresponding push plate close to the fourth empty space into the fourth empty space, and push the push plate located in the fourth empty space to push out the corresponding push plate close to the tail of the cooling zone structure; or, the tail of the high-temperature purification zone structure is connected to the side wall of the head of the cooling zone structure, and a fourth empty space is provided at the head of the cooling zone structure. The other two transmission devices can respectively push the push plate located in the third empty space to push the corresponding push plate close to the tail of the high-temperature purification zone structure into the fourth empty space, and push the push plate located in the fourth empty space to push out the corresponding push plate close to the tail of the cooling zone structure.

2. The graphite purification device according to claim 1, characterized in that: A heating device is provided on the drying zone structure, and the drying temperature in the drying zone structure is less than or equal to 300°C.

3. The graphite purification device according to claim 1, characterized in that: A first air inlet and a second air inlet are provided at the head of the low-temperature reaction zone structure, and a first exhaust port is provided at the tail thereof, the air inlet pipeline is connected to the first air inlet, the second air inlet is connected to the first end of the return pipeline and the first end of the first exhaust pipeline in a switchable manner, and the second end of the return pipeline is connected to the second air inlet.

4. The graphite purification device according to claim 1, characterized in that: A condensing device and an adsorption device are arranged on the return pipeline.

5. The graphite purification device according to claim 1, characterized in that: A third air inlet and a second air outlet are respectively provided at the head and the top of the high-temperature purification zone structure, and are respectively connected to the first protective gas pipeline and the second exhaust pipeline; A circulating water cooling device is provided on the cooling zone structure, and a fourth air inlet and a third air outlet are respectively provided at the head and the tail of the cooling zone structure, and are respectively connected to the second protective air pipeline and the third exhaust pipeline.

6. The graphite purification device according to claim 1, characterized in that: A vacuum pump is provided on the first exhaust pipeline, the second exhaust pipeline and the third exhaust pipeline, and the vacuum pump is also connected to an exhaust gas treatment device.

7. The graphite purification device according to claim 6, characterized in that: The tail gas treatment device comprises a filtering device, a desulfurization and denitrification device and an alkali solution spraying device which are sequentially connected in series along the air flow direction.

8. The graphite purification device according to claim 1, characterized in that: The tail of the cooling zone structure is an open end, and a nozzle assembly and a gas supply pipeline are provided at the tail of the cooling zone structure. The nozzle assembly is arranged at the top of the cooling zone structure, and the gas supply pipeline is connected to the nozzle assembly to form an air curtain at the open end.

9. The graphite purification device according to claim 1, characterized in that: The graphite purification device further comprises a control device, and the control device is electrically connected to both the door structure and the transmission device.

10. A graphite purification method, characterized in that: The graphite purification device according to any one of claims 1 to 9 is used for treatment, and the graphite purification method comprises: Place the material receiving device filled with graphite powder to be purified into the drying zone structure to remove moisture from the graphite powder; Pushing the dried material holding device containing graphite powder into the low-temperature reaction zone structure, introducing a mixed gas of reaction gas and protective gas into the low-temperature reaction zone structure, so that solid impurities in the graphite powder react with the reaction gas to generate halide impurities, and returning the unreacted reaction gas to the low-temperature reaction zone structure; Pushing the material receiving device containing the graphite powder after the reaction is completed into the high-temperature purification zone structure to gasify the halide impurities in the graphite powder; The gasified graphite powder containing device is pushed into the cooling zone structure to cool the graphite powder to obtain a purified graphite powder product.

Images