Preparation method of graphite crucible

Abstract

The invention relates to the technical field of graphite crucibles, and provides a graphite crucible preparation method, which comprises: a crushing and screening step: crushing and screening a graphitized coke raw material to obtain a particle material; a powder preparation step: grinding the graphitized coke raw material into powder to obtain first powder, wherein the first powder is powdery; a shaping step: shaping the first powder to remove edges and corners of the first powder to obtain second powder; a batching step: batching the granular material and the second powder material according to a preset proportion to obtain a graphitized coke ingredient; a mixing and kneading step: mixing the graphitized coke ingredient with asphalt to obtain a crucible paste material; and a forming step: preparing the crucible paste into the crucible. According to the embodiment of the invention, spheroidizing shaping can be carried out on the ground powder through the shaping step, so that the flowability of the powder can be improved, the compression density of the crucible is further improved, the mechanical property of the crucible is improved, the risk of damage to the crucible is reduced, and the cycle use frequency of the crucible is increased.

Description

Technical Field

[0001] The invention relates to the technical field of graphite crucibles, and in particular to a method for preparing a graphite crucible. Background Art

[0002] Graphite crucible is a graphite container used in the production of negative electrode materials in the Acheson graphitization furnace. It is responsible for heat conduction and isolating mixed materials during graphitization production. It is one of the main consumables of the Acheson graphitization furnace. Its number of recycling uses plays a vital role in reducing the graphitization cost of graphite negative electrode materials for lithium-ion batteries. Currently, the average recycling rate of mainstream products on the market is about 4 times.

[0003] The main forms of damage to graphite crucibles during the graphitization process include: cracks and oxidative corrosion. In the preparation process of graphite crucibles, due to the irregular shape of material particles and poor fluidity, it is not easy to compact in the crucible forming process, resulting in low crucible density and poor mechanical properties, which leads to cracks or breakage in the graphite crucible. With the innovation of large-scale graphitization technology, the electricity consumption per ton of negative electrode materials continues to decline, and the proportion of graphite crucibles in the cost of negative electrode materials has become increasingly larger, reaching a level comparable to the electricity consumption cost. Therefore, how to improve the quality of the crucible to increase the number of crucible cycles to reduce the consumption of crucibles per unit of negative electrode material is of great significance to reducing the cost and carbon emissions of negative electrode materials. Summary of the invention

[0004] Therefore, in order to overcome at least some of the defects and shortcomings in the prior art, an embodiment of the present invention provides a method for preparing a graphite crucible.

[0005] A method for preparing a graphite crucible provided in an embodiment of the present invention includes: a crushing and screening step: crushing and screening the graphitized coke raw material to obtain a granular material; a powder making step: grinding the graphitized coke raw material to obtain a first powder, wherein the first powder is in powder form; a shaping step: shaping the first powder to remove the edges and corners of the first powder to obtain a second powder; a batching step: batching the granular material and the second powder according to a preset ratio to obtain a graphitized coke batch; a kneading step: mixing the graphitized coke batch and asphalt to obtain a crucible paste; and a molding step: preparing the crucible from the crucible paste.

[0006] In a specific embodiment of the present invention, between the batching step and the kneading step, it also includes: an iron removal step: removing iron impurities in the graphitized coke batch.

[0007] In a specific embodiment of the present invention, the iron removal step specifically includes: removing the iron impurities by adsorbing the iron impurities in the graphitized coke batch by a magnetic rod.

[0008] In a specific embodiment of the present invention, before the kneading step, it also includes: an iron removal step: removing iron impurities in the granular material and the second powder material.

[0009] In a specific embodiment of the present invention, the kneading step includes: dry-mixing the graphitized coke ingredients evenly and heating them to a first temperature; stirring and kneading the asphalt and the graphitized coke ingredients at a second temperature for a preset time to obtain a kneaded crucible paste; and balancing the temperature of the kneaded crucible paste to obtain a uniform temperature crucible paste.

[0010] In a specific embodiment of the present invention, the dry mixing time is 30 minutes, the first temperature is 180° C.; the second temperature is 180° C., and the preset time is 40±5 minutes.

[0011] In a specific embodiment of the present invention, the step of stirring and kneading the asphalt and the graphitized coke ingredients at a second temperature for a preset period of time to obtain a kneaded crucible paste specifically includes: measuring liquid asphalt according to a preset amount through a metering scale, and mixing the asphalt with the graphitized coke ingredients in a mist form through an atomizing nozzle.

[0012] In a specific embodiment of the present invention, the molding step includes: adding a set weight of the crucible paste into the die; the punch and the crucible pressing device move along the vertical direction to the die to extrude the crucible paste to mold the crucible; the punch moves along the vertical direction toward the side away from the die; the crucible pressing device moves along the vertical direction toward the side away from the die; and the molded crucible is ejected to complete demolding.

[0013] In a specific embodiment of the present invention, after the male mold moves in a vertical direction toward a side away from the female mold, it also includes: a first cooling step: injecting 80-90% of a cooling medium into the formed crucible to pre-cool and shrink the crucible.

[0014] In a specific embodiment of the present invention, after the molded crucible is ejected to complete demolding, the process further includes: a second cooling step: continuously injecting a cooling medium into the demolded crucible, so that the cooling medium overflows from the crucible mouth after being filled.

[0015] As can be seen from the above, the embodiment of the present invention prepares a graphite crucible through a crushing and screening step, a powder making step, a shaping step, a batching step, a kneading step and a molding step. The powder after grinding can be spheroidized and shaped through the shaping step, which can improve the fluidity of the powder, thereby increasing the density of the crucible pressing, improving the mechanical properties of the crucible, thereby reducing the risk of crucible breakage and increasing the number of recycling times of the crucible. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 A schematic flow chart of a method for preparing a graphite crucible provided in an embodiment of the present invention.

[0018] Figure 2 Schematic diagram of the structure of a crusher used in the crushing step in an embodiment of the present invention.

[0019] Figure 3 A schematic flow chart of the iron removal step of the method for preparing a graphite crucible provided in an embodiment of the present invention.

[0020] Figure 4 for Figure 3 Schematic diagram of the structure of the iron removal equipment used in the iron removal step.

[0021] Figure 5 for Figure 4 Side view of the iron removal equipment.

[0022] Figure 6 for Figure 1 Schematic diagram of the process flow of the mixing step.

[0023] Figure 7 for Figure 6 Schematic diagram of the structure of the kneading equipment used in the kneading step.

[0024] Figure 8 for Figure 1 Schematic diagram of the process flow of the forming step.

[0025] Fig. 9 A schematic flow chart of the first cooling step in the method for preparing a graphite crucible provided in an embodiment of the present invention.

[0026] Fig.10 A schematic flow chart of the second cooling step in the method for preparing a graphite crucible provided in an embodiment of the present invention.

[0027] Fig.11 Another schematic flow chart of a method for preparing a graphite crucible provided in an embodiment of the present invention.

[0028] Main component identification: 100, crusher; 101, first material inlet; 102, first material outlet; 110, cylinder; 120, rotating shaft; 130, breaker; 140, pulley; 200, iron removal equipment; 201, first connecting flange; 202, second connecting flange; 210, magnetic rod; 220, scraper; 230, iron filings collection box; 240, material transfer box; 250, driving device; 260, observation port; 270, iron filings discharge port; 300, kneading equipment; 301, second material inlet; 302, second material outlet; 310, mixing preheating pot; 311, mixer; 320, kneading pot; 321, kneading machine; 330, temperature equalizing pot; 340, atomizing nozzle. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments described in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back, top, and bottom) in the embodiments of the present invention are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. In the embodiments of the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0031] See also Figure 1 , a method for preparing a graphite crucible provided by an embodiment of the present invention may, for example, include the following steps: S10, crushing and screening step: crushing and screening the graphitized coke raw material to obtain a granular material; S20, a powder making step: grinding the graphitized coke raw material to obtain a first powder, wherein the first powder is in a powdery state; S30, a shaping step: shaping the first powder to remove edges and corners of the first powder to obtain a second powder; S40, batching step: batching the granular material and the second powder material according to a preset ratio to obtain graphitized coke batch; S50, a kneading step: mixing the graphitized coke ingredients and asphalt to obtain a crucible paste; S60, forming step: preparing the crucible paste into a crucible.

[0032] Specifically, S10 crushing and screening step: crushing and screening the graphitized coke raw material to obtain pellets. Figure 2 The graphitized coke raw material can be fed into the crusher 100, for example, via a belt conveyor. The crusher 100 can include, for example, a cylinder 110, a rotating shaft 120, a breaker 130, a pulley 140, a first material inlet 101, and a first material outlet 102. The rotating shaft 120, the breaker 130, and the pulley 140 are arranged in the cylinder 110. The graphitized coke raw material enters the cylinder 110 through the first material inlet 101. The rotating shaft 120 and the pulley 140 drive the breaker 130 to crush the graphitized coke raw material, and the graphitized coke raw material is transmitted through the first material outlet 102. The crushed graphitized coke raw material can, for example, enter a vibrating screen via a bucket elevator for particle size classification. The screened material can, for example, return to the crusher 100 for crushing again. The crushed raw material is lifted by the bucket elevator and enters the vibrating screen again for screening to obtain particles of qualified size. In one implementation of this embodiment, the raw materials entering the crushing and screening step may also include return materials, and the return materials may include raw crushed materials, roasted waste products, graphitized and machined waste products, etc. After being roughly crushed by the crusher 100, the raw materials may be crushed again by a composite crusher, and then lifted by a bucket elevator to enter a vibrating screen for particle size classification. Of course, this embodiment is not limited to this.

[0033] S20 Powder making step: grinding the graphitized coke raw material to obtain a first powder, the first powder is in powder form. Specifically, the graphitized coke raw material can be ground, for example, by a powder making system, the particle size of the graphitized coke raw material entering the powder making system can be, for example, 0-2 mm, and the graphitized coke raw material is transported to the pre-grinding bin. The material in the pre-grinding bin can be fed into the corresponding Raymond mill, for example, via a screw feeder, and the control valves of the induced draft fan gate and various parts of the pipeline system are adjusted to make the air volume, air pressure, and wind speed in the powder making system appropriate, thereby obtaining the first powder that meets the production and quality requirements, the first powder can be, for example, in powder form.

[0034] S30 Shaping step: Shaping the first powder to remove the edges and corners of the first powder to obtain a second powder. The first powder after powdering can be shaped, for example, by a shaping machine (or spheroidizing machine) to remove the edges and corners of the first powder, so that the second powder is more spherical, thereby improving the fluidity of the second powder, so that the crucible can be pressed more densely when it is formed, and the crucible has a higher density.

[0035] S40 batching step: batching the granular material and the second powder material according to a preset ratio to obtain graphitized coke batching. The granular material and the second powder material of different particle sizes can be weighed by a batching scale under the batching bin according to the requirements of the preset batching ratio, for example, and the prepared graphitized coke batch can be fed into a collecting hopper, for example, via a screw, to transport the prepared materials to the kneading device 300. Then, the crucible paste is prepared to form a crucible through the kneading step S50 and the forming step S60.

[0036] The embodiment of the present invention prepares a graphite crucible through a crushing and screening step, a powder making step, a shaping step, a batching step, a kneading step and a molding step. The powder after grinding can be spheroidized and shaped through the shaping step, which can improve the fluidity of the powder, thereby increasing the density of the crucible pressing mold, improving the mechanical properties of the crucible, thereby reducing the risk of crucible breakage and increasing the number of recycling times of the crucible.

[0037] In one implementation of this embodiment, see Figure 3 , between the batching step and the kneading step, it also includes: S41, iron removal step: removing iron impurities in the graphitized coke batching. In another implementation of this embodiment, before the kneading step, it also includes: iron removal step: removing iron impurities in the pellets and the second powder.

[0038] Specifically, the iron removal step can remove iron impurities in the graphitized coke batch or pellets, and the second powder, for example, by using an iron removal device 200. Since the grinding equipment and the like are made of carbon steel, iron filings or iron powder will be generated in the previous process and mixed into the pellets, the first powder, the second powder or the graphitized coke batch, and metal elements such as iron in the material will be gasified and volatilized during graphitization, which may cause pores or cracks inside the crucible. By removing iron from the graphitized coke batch or pellets and the second powder, iron impurities in the raw materials themselves and introduced during the preparation are removed, so as to avoid pores left due to the volatilization of iron substances during graphitization, which may become a crack source.

[0039] See also Figure 4 and Figure 5 The iron removal device 200 may include, for example, a magnetic rod 210, a scraper 220, an iron chip collecting box 230 and a material transfer box 240. The magnetic rod 210 may be disposed in the material transfer box 240, and the scraper 220 may be provided with a through hole, through which the magnetic rod 210 passes to connect the iron chip collecting box 230. The magnetic rod 210 may be, for example, an electromagnet or a permanent magnet, and is used to remove iron powder or iron chips from the powder material. The magnetic strength of the magnetic rod 210 is not less than 10,000 Gauss.

[0040] To remove the iron impurities in the graphitized coke batch, before the configured graphitized coke batch is transported to the kneading device 300, an iron removal device 200 can be set on the pipeline before the kneading device 300 to remove the iron impurities in the graphitized coke batch. The first connecting flange 201 and the second connecting flange 202 can be connected to the pipeline between the batching bin and the kneading device 300. After the system is started, the graphitized coke batch can be passed through the round hole of the material passing box 240, and the magnetic force generated by the multiple magnetic rods 210 will absorb the iron materials such as iron filings and iron powder in the graphitized coke batch. After working for a period of time, the system stops, and the driving device 250, such as a cylinder, drives the multiple magnetic rods 210 and retracts them into the iron filing collection box 230. During the retraction process, the scraper 220 scrapes the iron filings adsorbed on the magnetic rods 210 and drops them into the iron filing collection box 230, and collects and processes the iron filings through the iron filing discharge port 270 under the iron filing collection box 230. The iron removal device 200 may be provided with an observation port 260, through which the user can observe the amount of iron filings on the magnetic rod 210 to determine the time to scrape the iron filings. By removing the iron impurities at one time before the kneading step, costs can be saved. In other embodiments, the iron removal device 200 may be provided in other processes to remove iron powder.

[0041] See also Figure 6 In one implementation of this embodiment, the kneading step S50 includes: S51, dry-mixing the graphitized coke ingredients and heating them to a first temperature; S52, stirring and kneading the asphalt and the graphitized coke ingredients at a second temperature for a preset time to obtain a kneading crucible paste; S53, equalizing the temperature of the kneading crucible paste to obtain the crucible paste with uniform temperature.

[0042] The prepared graphitized coke ingredients are kneaded by the kneading device 300. Figure 7 The kneading device 300 may include three layers from top to bottom, for example. The first layer is a mixing and preheating pot 310, which is provided with a mixer 311 inside, for mixing the materials evenly and preheating the materials. The second layer is a kneading pot 320, in which a kneading machine 321 is provided, and at the same time, the kneading pot 320 may be connected with an atomizing nozzle 340, for example, the atomizing nozzle 340 is connected to a liquid asphalt delivery pipe, and the end of the liquid asphalt delivery pipe extends into the kneading pot 320, and the atomizing nozzle 340 is connected to the end of the liquid asphalt delivery pipe, and the atomizing nozzle 340 is used to atomize the liquid asphalt in the liquid asphalt delivery pipe into atomized asphalt, so that the atomized asphalt can be fully mixed with the powdered graphitized coke ingredients until uniform. The third layer is a temperature equalizing pot 330, which is used to equalize the temperature of the crucible paste after kneading.

[0043] Specifically, the graphitized coke ingredients can be fed into the mixing preheating pot 310, for example, through the second material inlet 301, and the mixer 311 in the pot first dry-mixes the graphitized coke ingredients and heats them to a first temperature, which can be, for example, 180°C, and the dry-mixing time can be, for example, 30 minutes. The liquid asphalt in the high-level tank can be measured according to a preset amount, for example, by a metering scale, and then sprayed into the kneading pot 320 after atomization through an asphalt pump and an atomizing nozzle 340 at the end of the delivery pipe, while the kneading pot 320 is continuously stirred. The misted asphalt and the graphitized coke ingredients are fully stirred and kneaded in the kneading machine 321 of the kneading pot 320 for a preset time, and continue to heat and knead into a qualified kneading crucible paste. The kneading temperature is maintained at 180°C, and the kneading time is about 40±5 minutes. After the specified kneading time, the kneading crucible paste is discharged from the bottom of the kneading pot 320. The kneaded crucible paste enters the lower temperature-equalizing pot 330 for temperature equalization to obtain the crucible paste with uniform temperature. The crucible paste can be discharged from the second material outlet 302, for example.

[0044] By setting a mixer 311 in the mixing preheating pot 310, the mixing of the graphitized coke ingredients is strengthened to make it more uniform, thereby improving the uniformity of the material. In addition, in the prior art, when the asphalt pump delivers liquid asphalt to the kneading pot 320 through the delivery pipe to mix with the graphitized coke ingredients, due to the large opening at the end of the delivery pipe, a large amount of liquid asphalt rushes into the powder, making it easy for the powder to clump and agglomerate, resulting in poor uniformity of the material. Therefore, by setting an atomizing nozzle 340 at the end of the asphalt delivery pipeline, the asphalt flow does not enter the kneading pot in the form of a water flow and contact the powder, but enters the kneading pot in the form of a droplet and contact the powder when it is sprayed out. In this way, the volume of the powder block formed by the contact between the droplet and the powder is very small, reducing the possibility of powder clumping and agglomeration and reducing the size of the agglomerate, making the material very uniform and improving the uniformity of asphalt dispersion.

[0045] See also Figure 8 , the forming step in S60 includes: S61, adding a set weight of the crucible paste into the concave mold; S63, the male mold and the crucible pressing device move in a vertical direction to the female mold to extrude the crucible paste to form the crucible; S65, the male die moves in a vertical direction toward a side away from the female die; S67, the crucible pressing device moves in a vertical direction toward a side away from the concave die; S69, ejecting the formed crucible to complete demolding.

[0046] In the crucible forming process, the crucible paste is formed into a crucible through the cooperation of the convex mold, the crucible mouth device and the concave mold. Through the setting of the crucible mouth device, the crucible mouth device and the convex mold synchronously perform constant pressure positive extrusion on the crucible paste, which can effectively improve the density of the graphite crucible and ensure the uniformity of the density, thereby improving the strength and oxidation resistance of the graphite crucible.

[0047] See also Fig. 9 , after the male mold moves in the vertical direction toward the side away from the female mold, it also includes: S66, a first cooling step: injecting 80-90% of a cooling medium into the formed crucible to pre-cool and shrink the crucible. First, after the male mold is pulled out, 80-90% of a cooling medium is injected into the formed crucible, and the cooling medium can be, for example, water, to pre-cool and shrink the formed crucible, so as to facilitate ejection, thereby reducing the damage of the crucible when it is pushed out, and improving the yield rate of the formed crucible.

[0048] Further, see Fig.10 After the molded crucible is pushed out to complete demolding, the process further includes: S70, a second cooling step: continuously injecting a cooling medium into the demolded crucible, so that the cooling medium overflows from the crucible mouth after being filled. After the crucible is pushed away from the molding machine, a cooling medium (such as cold water) is continuously injected into the demolded crucible, so that the cooling medium overflows from the crucible mouth after being filled, thereby achieving rapid cooling, ensuring that the crucible solidifies without deformation, and further improving the crucible yield. At the same time, since there is no need to cool the demolded crucible in a cooling water pool, the investment cost can be reduced.

[0049] See also Fig.11 The method for preparing a graphite crucible provided in an embodiment of the present invention may, for example, further include the steps of roasting, machining and return material processing.

[0050] Specifically, the cooled crucible can be sent to the roasting workshop by an electric flatbed truck, unloaded by a forklift, and sent to the marshaling station for marshaling, and then assembled into a vertical installation form of 7 crucibles per group, and then clamped by a fixture crane and sent to a flatbed trolley on the furnace surface. The flatbed trolley moves to the corresponding furnace chamber for loading. For example, a 40-chamber full-ground open roasting furnace can be selected, with a total of 2 flame systems, each flame system 6 chambers in operation, and a roasting curve of 270 to 288 hours. Each furnace chamber has 5 furnace boxes, each furnace box is equipped with 4 layers, and each layer is double-row vertically equipped with 14 crucibles. Each furnace chamber is equipped with 280 crucibles, and the roasting furnace uses natural gas as fuel. The roasting suction crane completes the loading and unloading of raw and cooked blocks and fillers. After the furnace is loaded, the roasting furnace chambers of the green and fillers are connected to the heating system, and the green is roasted. The highest fire channel temperature of the heating furnace chamber is controlled between 1150 and 1200°C. When the furnace chamber temperature reaches the set roasting time, the heat source is cut off and the heating system is disconnected. After the furnace chamber cools to the specified time and temperature, the furnace unloading operation can be carried out. For example, the filling material covering the upper part of the crucible can be extracted by the suction crane first, and then the roasted product can be placed on the flat trolley on the furnace surface by the suction crane. The flat trolley will send the roasted product to the end of the furnace, and then the clamp crane will clamp it to the cleaning robot. After turning, cleaning, and grouping, the clamp crane will clamp it and store it in the cooked block storage area of ​​the roasting plant. The cleaning robot cleans the unloaded filling material and the filling material remaining in the crucible, and returns it to the filling material pool for storage through the collection system. The qualified products after cleaning and roasting are sent to the machining workshop by an electric flatbed trolley. The machining workshop is equipped with 3 crucible CNC machining centers and 1 crucible cover processing line. Crucible CNC machining center: The forklift delivers the roasted products to the automatic conveyor, and the conveyor sends them to the crucible centering machine to center the crucible, then the inner and outer circles of the blank are processed and the bottom surface is finely milled. After completing the above operations, the weight, length, wall thickness and other indicators of the crucible are measured and the label is printed, thus completing the entire processing process. Crucible cover processing line: The crucible cover is manually transported to the processing line, and the two surfaces and the outer circle are processed. Finally, the thickness and outer diameter are measured and the label is printed, thus completing the entire processing process. The machine-processed crushed materials generated during the machining process are collected by the belt conveyor and sent to the screening room for processing. First, they are crushed by the compound crusher, and then sent to the screening machine by the bucket elevator for screening. The screened materials are returned to the crusher for further crushing, and the qualified materials under the screen enter the return silo. A pneumatic conveying system is installed at the bottom of the warehouse to send the return materials to the roasting and crushing batching warehouse in the medium crushing and molding workshops. The processed products are then stored by forklifts, and the machined waste products are sent to the return material processing process by forklifts.

[0051] The roasting waste generated in the roasting workshop, the raw waste generated in the molding, and the processing waste generated in the machining are all sent to the return material processing by forklifts. A jaw crusher is set up for the return material processing to crush the return material once. The crushed return material is sent to the secondary crusher in the secondary crushing and molding workshop by a belt conveyor. By processing the micro-powder waste generated in the production process of negative electrode materials, the problem of low raw material recovery rate in the negative electrode material industry can be solved, the value of tailings can be increased, and the utilization rate of raw materials can be improved.

[0052] In summary, the preparation method of the graphite crucible provided by the embodiment of the present invention can improve the fluidity of the powder by spheroidizing and shaping the ground powder through the shaping step, thereby improving the density of the crucible pressing and improving the mechanical properties of the crucible. Secondly, the raw material is deironed through the deironing step to remove the iron impurities in the raw material itself and introduced during the preparation, so as to avoid the pores left by the volatilization of iron substances in graphitization, which becomes the source of cracks. In addition, by setting the asphalt adding method to atomization and continuous addition, the asphalt and graphitized coke ingredients can be fully mixed to ensure the uniformity of the crucible raw materials. Furthermore, the crucible is prepared by a positive constant pressure molding method, so that the density of the crucible is improved, and the density of the upper and lower parts is consistent, and even the density of the crucible mouth is higher, ensuring the uniformity of the crucible density. In addition, after the punch is pulled out after molding, a cooling medium is immediately injected into the crucible, so that the crucible is quickly cooled and the crucible shrinks, thereby reducing the breakage rate when the crucible is ejected; after the crucible is pushed out, water continues to be injected into the crucible, and overflows from the edge after filling, so as to achieve rapid cooling and ensure that the crucible is not deformed.

[0053] In addition, it can be understood that the aforementioned embodiments are only exemplary descriptions of the present invention. Under the premise that the technical features do not conflict, the structures do not contradict, and the purpose of the present invention is not violated, the technical solutions of the various embodiments can be arbitrarily combined and used in combination.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a graphite crucible, characterized in that: include: Crushing and screening step: crushing and screening the graphitized coke raw materials to obtain granular materials; Powder making step: grinding the graphitized coke raw material to obtain a first powder, wherein the first powder is in powder form; Shaping step: shaping the first powder to remove the edges and corners of the first powder to obtain a second powder; Batching step: batching the granular material and the second powder material according to a preset ratio to obtain graphitized coke batch; Kneading step: mixing the graphitized coke ingredients and asphalt to obtain a crucible paste; Forming step: preparing the crucible paste into a crucible.

2. The method for preparing a graphite crucible according to claim 1, wherein: Between the batching step and the kneading step, the method further comprises: Iron removal step: removing iron impurities in the graphitized coke batch.

3. The method for preparing a graphite crucible according to claim 2, wherein: The iron removal step specifically comprises: The iron impurities in the graphitized coke batch are adsorbed by a magnetic rod to remove the iron impurities.

4. The method for preparing a graphite crucible according to claim 1, wherein: Before the kneading step, the method further comprises: Iron removal step: removing iron impurities from the granular material and the second powder material.

5. The method for preparing a graphite crucible according to claim 2 or 4, characterized in that: The kneading step comprises: Dry-mixing the graphitized coke ingredients and heating them to a first temperature; Stirring and kneading the asphalt and the graphitized coke ingredients at a second temperature for a preset time to obtain a kneading crucible paste; The temperature of the kneading crucible paste is equalized to obtain the crucible paste with uniform temperature.

6. The method for preparing a graphite crucible according to claim 5, characterized in that: The dry mixing time is 30 minutes, the first temperature is 180° C.; the second temperature is 180° C., and the preset time is 40±5 minutes.

7. The method for preparing a graphite crucible according to claim 5, characterized in that: The step of stirring and kneading the asphalt and the graphitized coke ingredients at a second temperature for a preset time to obtain a kneading crucible paste specifically comprises: The liquid asphalt is measured according to a preset amount by a metering scale, and the asphalt is mixed with the graphitized coke batch in a mist form through an atomizing nozzle.

8. The method for preparing a graphite crucible according to claim 1, characterized in that: The forming step comprises: Adding a set weight of the crucible paste into the concave mold; The male die and the crucible pressing device move in a vertical direction to the female die to extrude the crucible paste to form the crucible; The male die moves in a vertical direction toward a side away from the female die; The crucible pressing device moves in a vertical direction toward a side away from the concave die; The formed crucible is ejected to complete demoulding.

9. The method for preparing a graphite crucible according to claim 8, characterized in that: After the male die moves in a vertical direction toward a side away from the female die, the method further comprises: The first cooling step: injecting 80-90% of a cooling medium into the formed crucible to pre-cool and shrink the crucible.

10. The method for preparing a graphite crucible according to claim 8, characterized in that: After the molded crucible is ejected to complete demoulding, the method further comprises: The second cooling step: continuously injecting a cooling medium into the demoulding crucible, so that the cooling medium overflows from the crucible opening after being filled.

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