A pressure calcination process for producing high-purity graphite

Abstract

This invention discloses a pressure calcination process for producing high-purity graphite, relating to the field of graphite production technology, including the following steps: S1, mixing graphite raw materials with a binder; S2, placing the graphite raw materials containing the binder into a mold on a placement platform, and then placing the placement platform and the mold together into a calcination furnace; This invention uses a designed flipping mechanism to drive the mold to flip, realizing the exchange of positions between the upper and lower layers of graphite raw materials, allowing the previously underheated bottom raw materials to directly receive infrared radiation from the resistance wire, eliminating temperature gradients, improving calcination uniformity, and simultaneously working with a transparent pressure plate to compact and flatten the graphite raw materials in the mold before and after flipping, ensuring uniform heating for more complete carbonization of the binder, resulting in consistent density of the green body, and promoting the full volatilization of impurities in various areas of the raw materials, laying the foundation for subsequent graphitization, and improving the purity and quality stability of high-purity graphite products.

Description

Technical Field

[0001] This invention belongs to the field of graphite production technology, specifically a pressure calcination process for producing high-purity graphite. Background Technology

[0002] High-purity graphite is widely used in high-end fields such as semiconductors, photovoltaics, aerospace, and nuclear industry due to its excellent high-temperature resistance, thermal and electrical conductivity, chemical stability, and low impurity content. Pressure calcination is one of the core processes in the production of high-purity graphite. Its core purpose is to gel and carbonize the mixed graphite raw material powder particles with the binder in a high-temperature and high-pressure environment in a calcination furnace to form a dense green body. At the same time, it removes moisture and volatile impurities from the raw materials, laying the foundation for subsequent graphitization treatment.

[0003] In existing technologies, the mixed graphite raw material powder and binder are usually directly loaded into a mold, which is then placed on a platform inside the furnace for calcination. Because the heat radiation generated by the resistance wire is easily obstructed, the top area of ​​the mixture inside the mold can directly receive heat radiation, while the bottom area receives significantly less heat radiation due to the double obstruction of the platform and the bottom of the mold. Furthermore, heat transfer also involves multiple layers of conduction losses at the bottom of the mold and the platform, resulting in a significant temperature gradient between the upper and lower areas of the graphite raw material within the mold. This not only leads to uneven heating of the raw material within the mold, reducing the calcination effect on the graphite, but also results in insufficient volatilization of impurities at the bottom of the raw material. These residual impurities directly affect the purity of the product after subsequent graphitization treatment. Therefore, we propose a pressure calcination process for producing high-purity graphite. Summary of the Invention

[0004] The purpose of this invention is to provide a pressure calcination process for producing high-purity graphite, so as to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a pressure calcination process for producing high-purity graphite, comprising the following steps:

[0006] S1. Mix the graphite raw material and the binder together;

[0007] S2. Place the graphite raw material containing the binder into the mold on the placement table, and then place the placement table and the mold together into the calcining furnace;

[0008] S3. Turn on the resistance wire to heat the graphite material in the mold. During the heating process, the graphite material in the mold is flipped by the flipping mechanism.

[0009] S4. During the initial heating process, the graphite raw material in the mold is initially flattened by a transparent pressure plate.

[0010] S5. After baking, remove the mold and demold the shaped blank from the mold.

[0011] S6. The billet is transferred into a graphitization furnace and graphitized under an inert atmosphere and at a high temperature to allow the carbon atoms in the billet to rearrange fully to form a regular graphite crystal structure, ultimately obtaining a high-purity graphite product.

[0012] Preferably, the roasting furnace in step S2 includes a base, a furnace body mounted on the base, and a resistance wire fixed to the inner wall of the furnace body. The furnace body is equipped with a placement platform and a mold positioned on top of the placement platform. The furnace body is also equipped with a tilting mechanism, which includes:

[0013] Rotating the rotating rod mounted on the furnace body and the concave plate fixed to one end of the rotating rod are used to flip the mold.

[0014] The concave plate has a locking stud connected to it by threads, which is used to fix the mold.

[0015] A transparent pressure plate is provided above the mold to flatten the graphite raw material inside the mold.

[0016] Preferably, an upper hydraulic rod is fixedly installed on the top of the furnace body via a support plate, and a movable rod is fixedly installed on the working end of the upper hydraulic rod.

[0017] Preferably, a lower hydraulic rod is fixedly installed inside the base to drive the placement platform and the mold to move up and down;

[0018] A lower frame is fixedly installed at the top working end of the lower hydraulic rod, and four lower rods are fixedly installed on the lower frame.

[0019] Preferably, the mold is provided with a blocking component, the blocking component comprising:

[0020] Multiple baffles are slidably installed inside the mold to block the bottom of the graphite raw material inside the mold.

[0021] Preferably, the mold is provided with two moving parts, each including a gear rotatably disposed on the back of the mold, wherein a second L-shaped gear and a first L-shaped gear are respectively meshed on the gear, and a contact plate is fixedly disposed at the end of the first L-shaped gear.

[0022] Preferably, the movable component further includes a left hydraulic rod disposed on one side of the furnace body and a right hydraulic rod disposed on the other side of the furnace body, wherein a left push rod is fixedly disposed at the working end of the left hydraulic rod and a right push rod is fixedly disposed at the working end of the right hydraulic rod.

[0023] Preferably, a cleaning component is provided on one side of the transparent pressure plate, the cleaning component comprising:

[0024] A concave brush is located on one side of a transparent pressure plate, and an upper brush strip is located at both ends of the concave brush and rotated via a rotating shaft. Mounting plates are fixedly installed on both sides of the upper brush strip, and fixing plates are fixedly installed on both ends of the concave brush. A connecting spring is fixedly installed between the fixing plates and the mounting plates.

[0025] Preferably, a linkage plate is fixedly provided on the back of the concave brush, an electric push rod is fixedly provided on the outside of the furnace body, and a movable rod is fixedly provided on the working end of the electric push rod through a connecting plate.

[0026] Preferably, a furnace cover is rotatably mounted on the front of the furnace body via a rotating shaft, and a pressure-increasing pipe and a pressure-reducing pipe are respectively mounted on the furnace body, with valves mounted on both the pressure-increasing pipe and the pressure-reducing pipe;

[0027] The bottom of the placement platform is fixed with two slide rails, and the bottom of the slide rails is equipped with tracks.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] (1) The present invention drives the mold to flip through the designed flipping mechanism, thereby realizing the exchange of positions between the upper and lower layers of graphite raw material. This allows the bottom raw material, which was originally underheated, to directly receive the infrared radiation of the resistance wire, eliminating the temperature gradient and improving the uniformity of calcination. At the same time, in conjunction with the transparent pressure plate, the graphite raw material in the mold can be compacted and flattened before and after flipping. The uniform heating makes the binder carbonized more fully, making the green body uniform in density. At the same time, it promotes the full volatilization of impurities in each area of ​​the raw material, laying the foundation for subsequent graphitization and improving the purity and quality stability of high-purity graphite products.

[0030] (2) The present invention combines the designed blocking components and moving parts. The baffle is driven by the moving parts. Before flipping, the top baffle is closed by the right hydraulic rod, gears, etc., to prevent the raw materials from spilling when the mold is flipped. After flipping, the new top (original bottom) baffle is opened by the left hydraulic rod, contact plate, etc., without affecting the subsequent heating and flattening, ensuring no loss of raw materials. The first L-shaped tooth frame and the second L-shaped tooth frame move synchronously in opposite directions through gear transmission, accurately controlling the baffle opening and closing. No manual operation is required. It is suitable for the high temperature and sealed environment inside the furnace, ensuring the automation and continuity of the roasting process, and indirectly improving the quality of the green body forming and the stability of the purity of high-purity graphite.

[0031] (3) The present invention uses a designed cleaning component, a concave brush and an upper brush strip to clean the graphite dust and other adhering substances on the upper and lower surfaces of the transparent pressure plate, avoids blocking the infrared radiation of the resistance wire, ensures that heat is efficiently transferred to the raw materials in the mold, maintains the uniformity of heating, and the upper brush strip can rotate to avoid the moving rod when it encounters it with the help of a connecting spring, and resets after passing through, so that there are no dead corners in cleaning. Attached Figure Description

[0032] Figure 1This is a schematic diagram of the structure of the present invention;

[0033] Figure 2 This is a schematic diagram of the rear view structure of the present invention;

[0034] Figure 3 This is a schematic diagram of the furnace body structure of the present invention;

[0035] Figure 4 This is a bottom view of the furnace body structure of the present invention;

[0036] Figure 5 This is a schematic cross-sectional view of the furnace body of the present invention;

[0037] Figure 6 This is a schematic diagram of the furnace body structure from the right side;

[0038] Figure 7 This is a schematic diagram of the mold and placement platform structure of the present invention;

[0039] Figure 8 This is a schematic diagram of the transparent pressure plate structure of the present invention;

[0040] Figure 9 This is a schematic cross-sectional view of the mold and concave plate of the present invention;

[0041] Figure 10 This is a schematic diagram of the rear view structure of the mold of the present invention;

[0042] Figure 11 This is a schematic diagram of the cleaning component structure of the present invention;

[0043] Figure 12 This is a partial structural diagram of the concave brush and upper brush strip of the present invention;

[0044] In the diagram: 100, base; 101, furnace body; 102, furnace cover; 103, mold; 104, placement platform; 105, track; 106, resistance wire; 200, upper hydraulic rod; 201, moving rod; 202, lower frame; 203, lower hydraulic rod; 204, lower rod; 205, locking stud; 206, concave plate; 207, transparent pressure plate; 208, rotating rod; 300, left hydraulic rod; 301, right hydraulic rod; 302, baffle; 303, first L-shaped gear frame; 304, second L-shaped gear frame; 305, gear; 307, contact plate; 400, electric push rod; 401, concave brush; 402, linkage plate; 403, connecting spring; 404, upper brush strip. Detailed Implementation

[0045] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1

[0047] Please see Figures 1-12 This invention provides a technical solution: a pressure calcination process for producing high-purity graphite, comprising the following steps:

[0048] S1. Mix the graphite raw material and the binder together;

[0049] S2. Place the mixed graphite raw material containing binder into the mold 103 on the placement platform 104, and then place the placement platform 104 and the mold 103 together into the calcining furnace.

[0050] S3. Turn on the resistance wire 106 to heat the graphite material in the mold 103. During the heating process, the graphite material in the mold 103 is flipped by the flipping mechanism to increase the uniformity of the upper and lower heating of the graphite material.

[0051] S4. During the heating process, the graphite raw material in the mold 103 is initially flattened by the transparent pressure plate 207.

[0052] S5. After baking, remove mold 103 and demold the shaped blank from mold 103.

[0053] S6. The billet is transferred into a graphitization furnace and graphitized under an inert atmosphere and at a high temperature to allow the carbon atoms in the billet to rearrange fully to form a regular graphite crystal structure, and finally obtain a high-purity graphite product.

[0054] The roasting furnace in step S2 includes a base 100, a furnace body 101 mounted on the base 100, and a resistance wire 106 fixed to the inner wall of the furnace body 101. The resistance wire 106 generates heat when energized, which is transferred to the mold 103 via infrared radiation. The furnace body 101 contains a placement platform 104 and a mold 103 positioned on top of the placement platform 104. The furnace body 101 is equipped with a tilting mechanism, which includes:

[0055] Rotary rod 208 is rotatably mounted on furnace body 101 and concave plate 206 is fixed to one end of rotary rod 208. All components located inside furnace body 101 are designed to withstand the high temperature inside furnace body 101 and are used to flip mold 103. Mold 103 is located inside concave plate 206. A motor is fixedly mounted on the back of furnace body 101 and the working end of the motor is fixedly connected to rotary rod 208. The motor can drive rotary rod 208 to rotate.

[0056] The concave plate 206 is connected to a locking stud 205 by a thread to fix the mold 103. The working end of the locking stud 205 contacts the side of the mold 103. When the rotating rod 208 is rotated 180 degrees under the drive of the motor, the concave plate 206, the locking stud 205 and the mold 103 are rotated 180 degrees, realizing the exchange of positions between the upper and lower layers of graphite raw material and improving the uniformity of heating.

[0057] A transparent pressure plate 207 is installed above the mold 103. The transparent pressure plate 207 is a transparent yttrium oxide ceramic plate, which can not affect the passage of infrared radiation light generated by the resistance wire 106, and can withstand high temperatures to flatten the graphite raw material. In the early stage of calcination heating of the graphite raw material in the mold 103, the binder softens and the graphite raw material particles rearrange. Due to gravity, local sedimentation will occur, resulting in the bottom graphite raw material being compacted and the surface being loose, forming a density difference of "loose at the top and tight at the bottom". At this time, the transparent pressure plate 207 descends to compact and flatten the graphite raw material in the mold 103. The graphite raw material inside mold 103 is compacted both top and bottom, making the raw material more densely packed and avoiding density stratification of "loose at the top and tight at the bottom," thus improving the quality of the green body forming. At the same time, the compaction and flattening creates a uniform structural basis for the carbon atom rearrangement in the subsequent graphitization stage, reducing crystal defects and making it easier for impurities to volatilize or migrate to the surface of the green body at high temperatures, making subsequent cleaning easier. The dense green body is less prone to deformation at the high temperature of subsequent graphitization, avoiding the entry of impurities due to structural damage, and ensuring that the purity of the final product is stable at the target level. It is used to flatten the graphite raw material inside mold 103.

[0058] Example 2

[0059] Please refer to Example 1. Figures 1-11 The top of the furnace body 101 is fixedly equipped with an upper hydraulic rod 200 via a support plate, and a moving rod 201 is fixedly equipped at the working end of the upper hydraulic rod 200. The bottom of the moving rod 201 extends to the surface of the transparent pressure plate 207. The upper hydraulic rod 200 drives the moving rod 201 to move downward, thereby causing the transparent pressure plate 207 to move downward to flatten the graphite raw material. The upper hydraulic rod 200 can precisely control the pressure and the downward speed to avoid excessive pressure causing the raw material particles to break, or insufficient pressure failing to achieve the compaction effect.

[0060] A lower hydraulic rod 203 is fixedly installed inside the base 100. When the mold 103 is about to be flipped, the lower hydraulic rod 203 can drive the placement platform 104 to move downward, so as to prevent the mold 103 from hitting the placement platform 104 when it is flipped, and to make enough space for the mold 103 to flip, so as to facilitate the rotation and flipping of the mold 103. It is used to drive the placement platform 104 and the mold 103 to move up and down.

[0061] A lower frame 202 is fixedly installed at the top working end of the lower hydraulic rod 203, and four lower rods 204 are fixedly installed on the lower frame 202.

[0062] Example 3

[0063] Please refer to Example 2. Figures 1-10 The mold 103 is provided with a blocking component, which includes:

[0064] Multiple baffles 302 are slidably installed inside the mold 103. These baffles 302 block the bottom of the mold 103, preventing the graphite material inside from falling out during the flipping process. When the mold 103 flips upwards, the two upper baffles 302 open, while the two lower baffles 302 close. When not flipped, the two upper baffles 302 are open, and the two lower baffles 302 are closed. Before flipping, the right hydraulic rod 301 is activated, extending its working end outwards and moving the right push rod. The end of the right push rod then contacts the first L-shaped gear 303 above the mold 103, pushing it closer to the mold 103. At this time, the gear 305 causes the second L-shaped gear 304 above the mold 103 to also move towards the mold 103. Simultaneously, the two upper baffles 302 move towards the mold 103. The movement of the center direction closes the mold, which is completed before the mold 103 is flipped. This effectively blocks the raw material, preventing it from spilling during the flipping process and ensuring that all the raw material participates in heating, thus guaranteeing the stability of the green body quality. Then, after the mold 103 is flipped 180 degrees, the two baffles 302, which were originally closed at the bottom of the mold 103 (now above the mold 103 after flipping), are activated by the left hydraulic rod 300. The working end extends outward, driving the left push rod to move closer to the mold 103, contacting and pushing the contact plate 307 above the mold 103 away from the mold 103. This causes the first L-shaped toothed frame 303 to move away from the mold 103, thereby opening the two closed baffles 302 above the mold 103. The baffles 302 ensure the integrity of the raw material during the flipping process, preventing material loss and contamination, while not affecting the normal roasting process and ensuring the quality of the green body. They are used to block the bottom of the graphite raw material inside the mold 103.

[0065] The mold 103 is provided with two moving parts, including a gear 305 rotatably disposed on the back of the mold 103. When the first L-shaped gear 303 moves to the left or right, it drives the gear 305 to rotate, thereby driving the second L-shaped gear 304 to move to the right or left, so that the first L-shaped gear 303 and the second L-shaped gear 304 move in opposite directions, thereby driving the two baffles 302 to move in opposite directions to close or move in opposite directions to open. The gear 305 is respectively meshed with the second L-shaped gear 304 and the first L-shaped gear 303. One end of the second L-shaped gear 304 and the first L-shaped gear 303 are fixed to the baffles 302. The end of the first L-shaped gear 303 is fixedly provided with a contact plate 307.

[0066] The moving part also includes a left hydraulic rod 300 disposed on one side of the furnace body 101 and a right hydraulic rod 301 disposed on the other side of the furnace body 101. The working end of the left hydraulic rod 300 is fixedly provided with a left push rod, the end of the left push rod extends into the interior of the furnace body 101, and the end of the left push rod can contact the contact plate 307.

[0067] The working end of the right hydraulic rod 301 is fixedly provided with a right push rod, the end of which extends into the interior of the furnace body 101, and the end of which can contact one side of the first L-shaped toothed frame 303.

[0068] Example 4

[0069] Please refer to Example 3. Figures 1-8 , Figure 11 and 12 A cleaning component is provided on one side of the transparent pressure plate 207. The cleaning component includes:

[0070] A concave brush 401 is located on one side of the transparent pressure plate 207, and upper brush strips 404 are rotatably mounted at both ends of the concave brush 401 via rotating shafts. Mounting plates are fixedly mounted on both sides of the upper brush strips 404, and fixing plates are fixedly mounted on both ends of the concave brush 401. A connecting spring 403 is fixedly mounted between the fixing plates and the mounting plates. The transparent pressure plate 207 does not affect the passage of the resistance wire 106 through the interior. During use, graphite dust (dust raised by graphite raw materials during the flipping process or dust generated during heating) easily adheres to the upper and lower surfaces of the transparent pressure plate 207. The lower surface of the transparent pressure plate 207 is cleaned by the concave brush 401, and the upper surface is cleaned by the two upper brush strips 404. To prevent the adhesive from covering the transparent pressure plate 207, which would make it difficult for the infrared thermal radiation light generated by the resistance wire 106 to penetrate the transparent pressure plate 207, the two upper brush strips 404, when they encounter the moving rod 201 located at the top of the transparent pressure plate 207, can rotate to avoid the obstruction of the moving rod 201 through the action of the rotating shaft and the connecting spring 403. This allows for the cleaning of all the adhesive on the upper surface of the transparent pressure plate 207, avoiding dead corners in the area of ​​the moving rod 201. After encountering the moving rod 201, the upper brush strip 404 rotates through the rotating shaft and compresses the connecting spring 403 to avoid the moving rod 201. After passing through, it resets under the elastic force of the connecting spring 403 and continues cleaning, leaving no dead corners.

[0071] A linkage plate 402 is fixedly installed on the back of the concave brush 401. An electric push rod 400 is fixedly installed on the outside of the furnace body 101. The working end of the electric push rod 400 is fixedly installed with a movable rod through a connecting plate. The movable rod extends to the surface of the linkage plate 402. The working end of the electric push rod 400 can drive the linkage plate 402 to move back and forth in the left and right directions, thereby driving the concave brush 401 and the two upper brush strips 404 to move back and forth to clean the upper and lower surfaces of the transparent pressure plate 207. The concave brush 401 and the upper brush strips 404 are both carbon fiber brushes, which can withstand the high temperature inside the furnace body 101.

[0072] In this embodiment, a furnace cover 102 is rotatably mounted on the front of the furnace body 101 via a rotating shaft. A pressure-increasing pipe and a pressure-reducing pipe are respectively mounted on the furnace body 101. Valves are mounted on both the pressure-increasing pipe and the pressure-reducing pipe. Gas is added into the furnace body 101 through the pressure-increasing pipe to achieve pressurization. The gas acts on the raw material, which can further reduce the gaps between graphite particles, squeeze out residual air, and allow the binder to more tightly wrap the particles, reducing porosity. At the same time, the pressurized environment can inhibit the excessive expansion of volatiles generated during the pyrolysis of the binder, avoid defects such as bulging and cracking in the green body, and ensure that the green body structure is uniform and dense.

[0073] The bottom of the placement platform 104 is fixedly equipped with two slide rails, and the bottom of the slide rails is equipped with a track 105. The slide rails can slide on the track 105. The track 105 is fixed to the top of the lower rod 204. When the placement platform 104 is placed into the furnace body 101, the slide rail at the bottom of the placement platform 104 is moved to the track 105 inside the furnace body 101 by mechanical equipment at the front position of the furnace body 101. The placement platform 104 and the mold 103 are placed into the furnace body 101 (at this time, the mold 103 is located inside the concave plate 206). The moving rod 201, the left push rod, the right push rod, the lower rod 204, the movable rod, the rotating rod 208 and the furnace body 101 are all sealed with high-purity graphite sealing rings. The high-purity graphite sealing rings can withstand the high temperature inside the furnace body 101.

[0074] Working principle and usage process of this invention:

[0075] In use, after the mold 103 is placed inside the furnace body 101, the locking stud 205 inside the concave plate 206 is rotated to make the working end of the locking stud 205 make tight contact with the side of the mold 103, thus firmly fixing the mold 103 inside the concave plate 206. The furnace cover 102 is closed, and the resistance wire 106 fixed to the inner wall of the furnace body 101 is turned on. After the resistance wire 106 is energized, it generates infrared radiation heat, which directly acts on the graphite raw material inside the mold 103. The resistance wire 106 located above the mold 103... 6. Because the graphite material inside the mold 103 is directly irradiated by infrared radiation, the graphite material is heated well. In the initial stage of heating, the binder begins to soften, and the material is prone to settle due to gravity, forming a density difference between the upper and lower parts. At this time, the upper hydraulic rod 200 fixed by the support plate at the top of the furnace body 101 is activated. The working end of the upper hydraulic rod 200 extends and retracts, driving the moving rod 201 to move downward. The bottom of the moving rod 201 pushes the transparent pressure plate 207 to move downward simultaneously, applying pressure to the material inside the mold 103 to compact and flatten it.

[0076] To address the issue of uneven heating of graphite raw materials during calcination, the mold 103 needs to be flipped. First, the lower hydraulic rod 203, fixed inside the base 100, is activated. The working end of the lower hydraulic rod 203 retracts, causing the lower frame 202, lower rod 204, and placement platform 104 to move downwards, creating sufficient space for the mold 103 to flip. Next, the right hydraulic rod 301 on the other side of the furnace body 101 is activated. The working end of the right hydraulic rod 301 extends, causing the right push rod to move. The end of the right push rod pushes the first L-shaped gear frame 303 towards the mold 103. Since the first L-shaped gear frame 303 meshes with the gear 305 on the back of the mold 103, its movement causes the gear 305 to rotate, which in turn drives the second L-shaped gear frame 304 to move synchronously towards the mold 103. The two top baffles 302, fixedly connected to both, move towards the center and close. Finally, the mounting motor fixed to the back of the furnace body 101 is activated. The working end of the mounting motor drives... Rotating rod 208 rotates, driving concave plate 206, locking stud 205 and mold 103 to rotate 180 degrees simultaneously, realizing the exchange of positions between the upper and lower layers of raw materials; after the rotation is completed, the left hydraulic rod 300 on one side of the furnace body 101 is activated, the working end of the left hydraulic rod 300 extends and drives the left push rod to move, the end of the left push rod contacts the contact plate 307 fixed at the end of the first L-shaped gear frame 303 and pushes it to move away from the mold 103, and the second L-shaped gear frame 304 moves in the opposite direction through gear 305 transmission, and the two baffles 302 at the top (original bottom) move outward and open, continuing to heat the graphite raw materials inside the mold 103. During this period, the upper hydraulic rod 200 can be activated again to drive the transparent pressure plate 207 to move downward to flatten the raw materials inside the mold 103 again. The transparent pressure plate 207 is only for flattening during the initial heating. In the middle and later stages, it is only necessary to rotate and no flattening operation is required.

[0077] During heating and turning, the dust raised by the graphite raw material easily adheres to the upper and lower surfaces of the transparent pressure plate 207, affecting the penetration of infrared radiation through the transparent pressure plate 207. At this time, the electric push rod 400 fixed outside the furnace body 101 is activated. The working end of the electric push rod 400 drives the movable rod to move through the connecting plate. The movable rod drives the linkage plate 402 and the concave brush 401 fixed to the linkage plate 402 to move back and forth in the left and right directions. The concave brush 401 wipes the lower surface of the transparent pressure plate 207, and the upper brush strip 404, which is rotated through the rotating shaft at both ends, wipes the upper surface. When the upper brush strip 404 touches the movable rod 201, it rotates through the rotating shaft and compresses the connecting spring 403 to avoid the obstruction. After passing through, it resets under the elastic force of the connecting spring 403, realizing cleaning without dead corners and ensuring the light transmittance of the transparent pressure plate 207.

[0078] Maintain stable temperature and pressure inside the furnace, and keep it warm and pressurized for a period of time. During this period, the resistance wire 106 is continuously heated to fully carbonize the binder. Moisture, low-boiling-point impurities, and some volatile impurities in the raw materials are discharged through pyrolysis. After calcination, adjust the valve on the pressure relief pipe to slowly release the pressure inside the furnace, while maintaining an inert atmosphere until the temperature inside the furnace drops below 100°C to prevent damage to the green body due to sudden temperature changes or oxidation. After the temperature and pressure inside the furnace 101 drop to a safe range, open the furnace cover 102 and loosen the locking stud 205 by rotating it outwards. The mold 103 is no longer fixed. The placement platform 104 is pulled out of the furnace 101 through the cooperation of the track 105 and the slide rail. Loosen the locking stud 205, remove the mold 103, demold the formed green body from the mold 103, and then transfer it to the graphitization furnace for subsequent high-temperature graphitization treatment to finally obtain a high-purity graphite product.

[0079] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A pressure calcination process for producing high-purity graphite, characterized in that, Includes the following steps: S1. Mix the graphite raw material and the binder together; S2. Place the graphite raw material containing binder into the mold (103) on the placement platform (104), and then place the placement platform (104) and the mold (103) together into the calcining furnace; S3. Turn on the resistance wire (106) to heat the graphite material in the mold (103). During the heating process, the graphite material in the mold (103) is flipped by the flipping mechanism. S4. During the initial heating process, the graphite raw material in the mold (103) is initially flattened by a transparent pressure plate (207); S5. After baking, remove the mold (103) and demold the shaped blank from the mold (103); S6. The billet is transferred into a graphitization furnace and graphitized under an inert atmosphere and at a high temperature to allow the carbon atoms in the billet to rearrange fully to form a regular graphite crystal structure, and finally obtain a high-purity graphite product. The roasting furnace in step S2 includes a base (100), a furnace body (101) mounted on the base (100), and a resistance wire (106) fixed to the inner wall of the furnace body (101). The furnace body (101) has a placement platform (104) and a mold (103) mounted on top of the placement platform (104). The furnace body (101) is equipped with a tilting mechanism, which includes: Rotating the rotating rod (208) on the furnace body (101) and the concave plate (206) fixed to one end of the rotating rod (208) are used to flip the mold (103); The concave plate (206) is internally connected to a locking stud (205) via a thread, which is used to fix the mold (103); A transparent pressure plate (207) is provided above the mold (103) to flatten the graphite material inside the mold (103); The top of the furnace body (101) is fixedly provided with an upper hydraulic rod (200) by a support plate, and a moving rod (201) is fixedly provided at the working end of the upper hydraulic rod (200). A cleaning component is provided on one side of the transparent pressure plate (207), the cleaning component comprising: A concave brush (401) is provided on one side of the transparent pressure plate (207), and an upper brush strip (404) is provided at both ends of the concave brush (401) via a rotating shaft. Mounting plates are fixedly provided on both sides of the upper brush strip (404), and fixing plates are fixedly provided on both ends of the concave brush (401). A connecting spring (403) is fixedly provided between the fixing plate and the mounting plate. A linkage plate (402) is fixedly installed on the back of the concave brush (401), and an electric push rod (400) is fixedly installed on the outside of the furnace body (101), and a movable rod is fixedly installed at the working end of the electric push rod (400) through a connecting plate.

2. The pressure calcination process for producing high-purity graphite according to claim 1, characterized in that, The base (100) is internally fixed with a lower hydraulic rod (203) for driving the placement platform (104) and the mold (103) to move up and down; The lower hydraulic rod (203) has a lower frame (202) fixedly installed at its top working end, and four lower rods (204) are fixedly installed on the lower frame (202).

3. The pressure calcination process for producing high-purity graphite according to claim 1, characterized in that, The mold (103) is provided with a blocking component, the blocking component comprising: Multiple baffles (302) are slidably disposed inside the mold (103) to block the bottom of the graphite raw material inside the mold (103).

4. The pressure calcination process for producing high-purity graphite according to claim 1, characterized in that, The mold (103) is provided with two moving parts, including a gear (305) rotatably disposed on the back of the mold (103). The gear (305) is respectively meshed with a second L-shaped gear frame (304) and a first L-shaped gear frame (303). The end of the first L-shaped gear frame (303) is fixedly provided with a contact plate (307).

5. The pressure calcination process for producing high-purity graphite according to claim 4, characterized in that, The movable component also includes a left hydraulic rod (300) disposed on one side of the furnace body (101) and a right hydraulic rod (301) disposed on the other side of the furnace body (101). The working end of the left hydraulic rod (300) is fixedly provided with a left push rod, and the working end of the right hydraulic rod (301) is fixedly provided with a right push rod.

6. The pressure calcination process for producing high-purity graphite according to claim 1, characterized in that, A furnace cover (102) is rotatably mounted on the front of the furnace body (101) via a rotating shaft. A pressure pipe and a pressure relief pipe are respectively mounted on the furnace body (101), and valves are mounted on both the pressure pipe and the pressure relief pipe. The bottom of the placement platform (104) is fixedly provided with two slide rails, and the bottom of the slide rails is provided with a track (105).

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