A device and method for recovering silicon carbide growth waste materials

Abstract

This application discloses a silicon carbide growth residue recovery device and method, including a blowing device comprising a bulk container and a blowing assembly. The bulk container is inclined, with a first discharge port at its lower end and a second discharge port at its higher end. The blowing assembly is disposed inside the bulk container, located between the first and second discharge ports, and has at least one air nozzle adapted to blow away the residue and cause at least a portion of the residue to move toward the second discharge port. A feeding device is adapted to feed the residue into the bulk container, and the residue is adapted to slide down the bulk container and pass through the blowing assembly. A collecting device is adapted to collect the residue that has moved to the second discharge port. This application features simple operation, streamlined process, and low production cost.

Description

Technical Field

[0001] This application relates to the field of silicon carbide growth technology, specifically to a device and method for recovering silicon carbide growth residue. Background Technology

[0002] Silicon carbide (SiC) is a semiconductor material with a wide bandgap, high breakdown field strength, high electron saturation drift velocity, and high thermal conductivity. Its many excellent physicochemical properties make it a promising candidate for applications in aerospace, electronics, energy, and military industries. Furthermore, these superior properties make it ideal for fabricating high-temperature, high-frequency, radiation-resistant, high-power, and high-density integrated electronic devices.

[0003] Currently, silicon carbide single crystal materials used in device fabrication are generally grown using the PVT (Physical Vapor Transmission) method. Compared to the complex control and high cost of high-temperature chemical deposition (HTCVD) and the significant drawbacks of solution methods such as metal contamination and surface roughness, PVT technology is mature and the most widely used method for silicon carbide single crystal growth. Furthermore, the growth conditions for silicon carbide single crystals using PVT are simple, facilitating industrialization. However, it generates excessive waste; the amount of silicon carbide waste generated from a single batch can reach 70%–80%, which undoubtedly leads to a significant increase in costs and environmental pressure from waste accumulation for industrialization. Moreover, the amount of silicon carbide waste generated during post-processing is also considerable. In post-processing, ingot rounding, ingot trimming, wafer cutting, and polishing all generate large amounts of waste containing usable silicon carbide. Recycling and reusing this waste is a crucial issue that the silicon carbide industry urgently needs to address for low-cost and sustainable development. Efficient recycling and purification of this silicon carbide waste is the most critical step.

[0004] The main impurities in silicon carbide waste are: 1. A relatively large amount of carbon and silicon impurities, which come from the sublimation and crystallization of silicon carbide powder during the PVT process for growing silicon carbide single crystals. Due to the different volatilization rates of carbon and silicon, carbon and silicon are enriched, forming elemental carbon and elemental silicon. 2. A relatively small amount of trace impurities, which come from carbon powder, trace elements such as Na, Mg, Al, Fe, Zn, and Cu that are inherent in the silicon powder raw materials and generated by radiation in the single crystal growth furnace.

[0005] However, the existing silicon carbide growth residue recycling process has the following drawbacks: the recycling process is relatively complex and lengthy, and may require high-temperature roasting, hazardous chemical reagents such as strong acids and alkalis, etc., resulting in high recycling costs and being unfavorable for industrial production. Summary of the Invention

[0006] One objective of this application is to provide a device and method for recovering silicon carbide growth residues that is simple to operate, streamlined in process, and has low production costs.

[0007] To achieve the above objectives, the technical solution adopted in this application is: a silicon carbide growth residue recovery device, comprising:

[0008] A blowing and separating device includes a bulk material container and a blowing and separating component. The bulk material container is inclined, with a first discharge port at its lower end and a second discharge port at its higher end. The blowing and separating component is disposed inside the bulk material container and is located between the first discharge port and the second discharge port. The blowing and separating component is provided with at least one air nozzle, which is adapted to blow and separate residual material and cause at least a portion of the residual material to move toward the second discharge port.

[0009] A feeding device, the feeding device being adapted to feed surplus material into the bulk material container, the surplus material being adapted to slide down along the bulk material container and pass through the blowing assembly;

[0010] A collection device adapted to collect residual material that has moved to the second discharge port.

[0011] In some embodiments, the blowing device further includes an adjustment component connected to at least one end of the bulk container, the adjustment component being adapted to change the height difference between the lower end and the higher end of the bulk container.

[0012] In some embodiments, the adjusting assembly includes an adjusting pulley and a rotating shaft, the adjusting pulley being connected to the lower end of the bulk container, and the rotating shaft being rotatably connected to the higher end of the bulk container, the adjusting pulley being adapted to rotate the lower end of the bulk container relative to the higher end of the bulk container.

[0013] In some embodiments, the dispersing assembly further includes an air inlet pipe and a distributor. The air nozzle is disposed on the distributor, which is rotatably disposed within the bulk material container. The air inlet pipe passes through the bulk material container and connects to the distributor. The bulk material container has a long, narrow bulk material cavity. There are multiple air nozzles, which are evenly distributed perpendicular to the length of the bulk material cavity. The direction of rotation of the distributor is perpendicular to the distribution direction of the air nozzles. The distance between the air nozzles and the bulk material container at the bottom is configured to be greater than the maximum movable height of the remaining material within the bulk material container.

[0014] In some embodiments, the feeding device includes a feeding funnel and a flow regulator, the flow regulator being disposed on the feeding funnel and adapted to control the feeding speed of the feeding funnel; a feed inlet is provided at the higher end of the bulk material container, and a feeding channel is provided at the bottom of the feeding funnel, at least a portion of the feeding channel being adapted to extend into the bulk material container through the feed inlet; the coefficient of friction of the inner wall of the feeding channel is 0.2 to 0.5.

[0015] In some embodiments, the collecting device includes a collecting channel, a fan, and a storage box. A first end of the collecting channel faces the second discharge port, and a second end of the collecting channel is connected to the storage box. The fan is adapted to draw in residual material at the second discharge port through the first end of the collecting channel and transport it to the storage box via the second end of the collecting channel. The device also includes a frame, in which the blowing device is movably disposed. The feeding device and the first end of the collecting channel both extend into the frame.

[0016] A method for recovering silicon carbide growth residue includes the following steps:

[0017] S100 residual material processing: Take out the residual material from the furnace and pour it into the vibrating screen container. Place the vibrating screen container horizontally in the vibrating screen machine, put solid blocks in the vibrating screen container, and vibrate the screen machine to obtain dispersed residual material.

[0018] The S200 performs a single sorting process, adjusting the tilt angle of the bulk material container and the air pressure of the air inlet pipe, fully opening the feeding device, starting the collection device, pouring the dispersed residual material into the feeding device, receiving the first product falling from the second outlet, and collecting the second product blown to the first outlet.

[0019] S300 secondary sorting, readjust the tilt angle of the bulk container and the air pressure of the air inlet pipe, partially open the feeding device, and keep the collecting device in the open or closed state. Pour the second product into the feeding device, receive the third product falling from the second outlet, and collect the fourth product blown to the first outlet.

[0020] For S400 cleaning, place the first and third products in cleaning dishes respectively, wrap the fourth product with a filter screen and place it in the cleaning tank, turn on the ultrasonic cleaner, and repeat the water changing and cleaning process.

[0021] S500 drying: After cleaning, the first and third products are placed separately in a constant temperature drying oven. After drying, they are taken out and blown away the surface dust with a blower.

[0022] In some embodiments, in step S100, the amplitude direction of the vibrating screen includes vertical amplitude and horizontal amplitude, and the solid block includes at least one of silicon carbide spheres, silicon carbide crystals, and silicon carbide crystal spheres.

[0023] In some embodiments, the steps further include:

[0024] S600 performs a single sampling inspection, measuring the percentage of silicon carbide fragments in the first product. If the percentage of silicon carbide fragments is lower than the acceptable value, step S200 is repeated.

[0025] S700 Secondary sampling inspection measures the percentage of silicon carbide residue in the third product. If the percentage of silicon carbide residue is lower than the qualified value, step S300 is repeated.

[0026] In some embodiments, step S400 includes the following steps:

[0027] S410: Measure the turbidity of the liquid in the cleaning tank at the end of each cleaning cycle. The cleaning cycle ends when the turbidity is lower than the set value.

[0028] Compared with the prior art, the beneficial effects of this application are as follows:

[0029] 1. The silicon carbide growth residue recovery device of this application can separate carbon, silicon and carbon powder of different masses in silicon carbide residue by physical blowing. The device has low production cost, simple operation, strong adjustment capability and applicability, and high safety in use.

[0030] 2. The silicon carbide growth residue recycling method of this application can sort carbon, silicon and carbon powder of different qualities in silicon carbide residue step by step and reuse them as raw materials. It does not require high-temperature roasting, hazardous chemical reagents, strong acids and strong alkalis, etc., which simplifies the process, reduces the energy consumption of production and processing, reduces the cost of recycling, and thus reduces the difficulty of industrial production. Attached Figure Description

[0031] Figure 1 This is an overall structural view according to a preferred embodiment of the present application.

[0032] Figure 2 This is an overall structural view of the rack according to a preferred embodiment of the present application.

[0033] Figure 3 This is a schematic diagram of the state during a sorting process according to a preferred embodiment of this application.

[0034] Figure 4 This is a schematic diagram of the state during secondary sorting according to a preferred embodiment of this application.

[0035] Figure 5 This is a schematic diagram of the structure of a blowing assembly according to a preferred embodiment of the present application.

[0036] Figure 6 This is a schematic diagram of the structure of a feeding device according to a preferred embodiment of this application.

[0037] In the diagram: 1. Blowing and separating device; 11. Bulk container; 111. First discharge port; 112. Second discharge port; 113. Bulk chamber; 114. Feed inlet; 12. Blowing and separating assembly; 121. Air nozzle; 122. Air inlet pipe; 123. Diverter; 13. Adjusting assembly; 131. Angle adjustment pulley; 1311. Rotating handle; 132. Rotating shaft; 133. Hook rope; 2. Discharging device; 21. Discharging funnel; 211. Discharging channel; 22. Flow regulator; 3. Collection device; 31. Collection channel; 32. Storage box; 4. Frame. Detailed Implementation

[0038] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0039] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.

[0040] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0041] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0042] The following description, in conjunction with the accompanying drawings, further illustrates this application:

[0043] like Figures 1 to 6 As shown, this application provides a silicon carbide growth residue recovery device, including a blowing device 1, a feeding device 2, and a collecting device 3.

[0044] The blowing and separating device 1 includes a bulk material container 11 and a blowing and separating component 12. The bulk material container 11 is inclined and has a first discharge port 111 at its lower end and a second discharge port 112 at its higher end. The blowing and separating component 12 is disposed inside the bulk material container 11 and is located between the first discharge port 111 and the second discharge port 112. The blowing and separating component 12 is provided with at least one air nozzle 121, which is adapted to blow and separate residual material and cause at least a portion of the residual material to move toward the second discharge port 112.

[0045] The residual material entering the bulk material container 11 can be separated and selected by falling from the first discharge port 111 or being blown to the second discharge port 112 under the combined action of its own gravity, the friction between itself and the bulk material container 11, and the air pressure of the airflow blown out by the air nozzle 121. This process only requires parameter calculation in advance and setting the tilt angle of the bulk material container 11 and the air pressure of the airflow blown out by the air nozzle 121 according to the calculated parameters. It can basically eliminate the need for manual assistance and realize semi-automatic or even automatic sorting for large-scale and industrialized production. Compared with the existing technology that uses high-temperature roasting and dangerous chemical reagents such as strong acids and strong alkalis, the cost of recycling is lower and it is conducive to realizing industrial production.

[0046] The feeding device 2 is adapted to feed the surplus material into the bulk material container 11. The surplus material is adapted to slide down along the bulk material container 11 and pass through the blowing component 12 to ensure that each piece of surplus material falling can be affected by the airflow blown out by the air nozzle 121 of the blowing component 12.

[0047] The collecting device 3 is suitable for collecting residual material that has moved to the second discharge port 112. The residual material that can be dispersed by the airflow blown out by the air nozzle 121 and moves to the second discharge port 112 is usually fine in particle size and light in weight. It is generally impurities such as carbon powder and silicon carbide powder, which can be easily collected by the collecting device 3.

[0048] This recycling device can recycle the growth residue, reducing costs. The sorted residue has a more concentrated particle size, which facilitates the layered filling of raw materials in the crystal growth process.

[0049] like Figure 2 In the embodiment shown, the recycling device also includes a frame 4, the blowing device 1 is movably disposed in the frame 4, the first ends of the feeding device 2 and the collection channel 31 both extend into the frame 4, the frame 4 is used to support and fix the blowing device 1, the feeding device 2 and the collection device 3, and can also protect the blowing device 1, the feeding device 2 and the collection device 3.

[0050] In some embodiments, the frame 4 is an enclosed structure, which can reduce and control dust spillage during the sorting process, reduce the impact on the surrounding production environment, improve the work safety of operators, and also improve the collection effect of the collection device 3.

[0051] In some embodiments, the blowing device 1 further includes an adjustment component 13, which is connected to at least one end of the bulk material container 11. The adjustment component 13 is adapted to change the height difference between the lower end and the higher end of the bulk material container 11. The adjustment and change of the height difference is related to the tilt angle of the bulk material container 11. The change of the tilt angle of the bulk material container 11 can change the combined effect of the weight of the residual material itself, the friction between the residual material and the bulk material container 11, and the air pressure of the airflow ejected from the air nozzle 121, so that residual materials of different masses can be discharged from the first discharge port 111 or from the second discharge port 112.

[0052] It is understood that the adjustment component 13 can be connected to only the lower end or the higher end of the bulk material container 11 and change the height of that end, or it can be connected to both the lower end and the higher end of the bulk material container 11 at the same time and change the relative height difference between the two ends by controlling the movement of at least one of the lower end and the higher end. The connection method can be selected according to the specific structure, setting method and actual adjustment needs of the adjustment component 13.

[0053] like Figure 1 In the illustrated embodiment, the adjusting component 13 includes an adjusting pulley 131 and a rotating shaft 132. The adjusting pulley 131 is connected to the lower end of the bulk container 11, and the rotating shaft 132 is rotatably connected to the higher end of the bulk container 11. The adjusting pulley 131 is adapted to rotate the lower end of the bulk container 11 relative to the higher end of the bulk container 11. In this embodiment, the adjusting component 13 only controls the movement of the lower end of the bulk container 11, which can prevent the relative position between the higher end of the bulk container 11 and the collecting device 3 from changing too much, thereby maintaining the cooperative suction and collection of the higher end of the bulk container 11 by the collecting device 3.

[0054] In some embodiments, the angle-adjusting pulley 131 and the bulk material container 11 are connected by a hook rope 133. The angle-adjusting pulley 131 can retract or extend the hook rope 133 by rotating, thereby realizing the movement control of the lower end of the bulk material container 11.

[0055] In some embodiments, the angle-adjusting pulley 131 is provided with a rotating handle 1311, which extends through the frame 4 to the outside, making it convenient for operators to control and reducing the difficulty of operating the angle-adjusting pulley 131.

[0056] In some embodiments, the angle-adjusting pulley 131 is equipped with a locking device. After the rotation control of the angle-adjusting pulley 131 is completed by rotating the handle 1311, the rotation of the angle-adjusting pulley 131 can be restricted by the locking device, so that the tilt angle of the bulk material container 11 can be fixed.

[0057] like Figure 1 and Figure 5In the embodiment shown, the blowing assembly 12 further includes an air inlet pipe 122 and a distributor 123. An air nozzle 121 is disposed on the distributor 123. The distributor 123 is rotatably disposed inside the bulk material container 11. The air inlet pipe 122 passes through the bulk material container 11 and is connected to the distributor 123. The air inlet pipe 122 can be connected to an external air pump or other equipment to supply air to the distributor 123. Then, the gas is evenly distributed to the air nozzle 121 through the distributor 123.

[0058] In some embodiments, a regulating valve may be provided in the distributor 123 to control the airflow speed of the gas entering the air nozzle 121, thereby realizing numerical adjustment of the airflow pressure during the process of blowing away residual material.

[0059] In some embodiments, an adjustable air valve may be provided on the air nozzle 121 to precisely control the airflow speed ejected from each air nozzle 121, so that each air nozzle 121 can achieve the best blowing effect through adjustment.

[0060] like Figure 3 and Figure 4 In the embodiment shown, the bulk material container 11 is provided with a long strip-shaped bulk material cavity 113. The long strip structure of the bulk material cavity 113 allows the residual material to have a sufficiently long sliding distance, so that the air nozzles 121 can effectively disperse the residual material. There are multiple air nozzles 121, which can improve the dispersion efficiency. The air nozzles 121 are evenly distributed perpendicular to the length direction of the bulk material cavity 113. The rotation direction of the distributor 123 is perpendicular to the distribution direction of the air nozzles 121. When the distributor 123 rotates, it will not affect the relative position of the air nozzles 121 in the bulk material cavity 113, but only change the included angle between the front end of the air nozzle 121 and the bulk material cavity 113.

[0061] In some embodiments, when the residual material slides steadily in the bulk container 11, its upper surface can be approximated as a plane. The distribution direction of the air nozzles 121 is parallel to this plane, which can uniformly disperse the residual material, so that the finer particles and lighter weight can be dispersed and removed as much as possible, thereby improving the sorting efficiency. In addition, the blowing angle of the air nozzles 121 on the plane can be changed by rotating the distributor 123 to obtain the best blowing effect.

[0062] In some embodiments, the main cross-sectional shape of the material dispersing chamber 113 can be rectangular, and the distribution direction of the air nozzles 121 is parallel to the bottom surface of the material dispersing chamber 113, so that the residual material can pass through each air nozzle 121 with the thickness as uniform as possible, and achieve the same blowing effect.

[0063] It is understood that the main cross-sectional shape of the bulk material cavity 113 can also be circular, trapezoidal or other shapes, and the rectangle is only used as a preferred embodiment.

[0064] It is worth noting that the distance between the air nozzle 121 and the bulk material container 11 is configured to be greater than the maximum height of the residual material in the bulk material container 11. This reduces the probability of the residual material burying and clogging the air nozzle 121 when it slides down in the bulk material container 11, enabling the air nozzle 121 to maintain a stable blowing effect and improve the stability of the sorting process.

[0065] It is worth noting that the distance between the air nozzle 121 and the second discharge port 112 should not be too large. The distance should be sufficient to allow the finer and lighter residual material to move to the second discharge port 112 under the blowing of the air nozzle 121, so as to ensure the sorting effect.

[0066] In some embodiments, the feeding device 2 includes a feeding funnel 21 and a flow regulator 22. The flow regulator 22 is disposed on the feeding funnel 21 and is adapted to control the feeding speed of the feeding funnel 21 and control the amount of material falling from the feeding funnel 21 per unit time.

[0067] In some embodiments, the design of the feeding hopper 21 facilitates feeding, which can be done manually or automatically, thereby greatly improving sorting efficiency and reducing process cycle.

[0068] like Figure 6 In the embodiment shown, the flow regulator 22 preferably uses a pin, which has a simple structure, is easy to operate, and has low cost. The feeding speed of the feeding funnel 21 can be adjusted by changing the insertion depth of the pin.

[0069] In some embodiments, the flow regulator 22 may also be equipped with a regulating valve or other device for more precise flow regulation.

[0070] like Figure 1 , Figure 3 and Figure 4 In the illustrated embodiment, the higher end of the bulk material container 11 is provided with a feed inlet 114, and the bottom of the discharge funnel 21 is provided with a discharge channel 211. At least a portion of the discharge channel 211 is adapted to extend into the bulk material container 11 through the feed inlet 114. In this embodiment, the adjusting component 13 only controls the lower end of the bulk material container 11 to move, so that the relative position between the higher end of the bulk material container 11 and the discharge funnel 21 does not change too much, thereby maintaining the fit of the discharge channel 211 extending into the feed inlet 114 and ensuring the feeding effect.

[0071] In some embodiments, the feed inlet 114 is opened along the length of the bulk container 11. When the tilt angle of the bulk container 11 changes, the discharge channel 211 can move relative to the bulk container 11 along the feed inlet 114. In addition, the length of the discharge channel 211 needs to ensure that the discharge channel 211 can extend into the feed inlet 114 at both the maximum and minimum tilt angles of the bulk container 11 during sorting, so that the residual material falling from the discharge channel 211 can fully enter the bulk container 11, reducing the probability of residual material falling outside the bulk container 11 and reducing waste.

[0072] In some embodiments, the coefficient of friction of the inner wall of the feeding channel 211 is 0.2 to 0.5 to ensure that the remaining material can fall smoothly.

[0073] In some embodiments, the material of the feeding channel 211 is preferably acrylic. Acrylic is low in cost, easy to produce, has a friction coefficient that meets the requirements, and can also be made transparent to facilitate observation of the remaining material falling.

[0074] The collection device 3 includes a collection channel 31, a fan, and a storage box 32. The first end of the collection channel 31 faces the second discharge port 112, and the second end of the collection channel 31 is connected to the storage box 32. The fan is adapted to make the first end of the collection channel 31 suck up the residual material at the second discharge port 112 and transport it to the storage box 32 through the second end of the collection channel 31.

[0075] In some embodiments, the structure and material of the storage box 32 must meet explosion-proof requirements to avoid life-threatening dangers caused by an explosion after the powder enters the storage box 32, thereby improving production safety.

[0076] In some embodiments, the collection channel 31 is preferably made of a corrugated pipe, which allows for easy adjustment of the angle and is relatively easy to install.

[0077] In some embodiments, the first end of the collection channel 31 is spaced apart from the second discharge port 112, so that the first end of the collection channel 31 reduces the suction effect on the residual material sliding down from the second discharge port 112 into the bulk container 11.

[0078] This application also provides a method for recovering silicon carbide growth residue, including the following steps:

[0079] S100 residual material processing: Take out the residual material from the furnace and pour it into the vibrating screen container. Place the vibrating screen container horizontally in the vibrating screen machine, put solid blocks into the vibrating screen container, and vibrate the screen machine to obtain dispersed residual material.

[0080] In step S100, the vibration direction of the vibrating screen includes vertical and horizontal vibration. In the traditional process of vibrating and screening silicon carbide residue, only horizontal vibration is performed. In this application, by increasing the vertical vibration, the dispersing effect of silicon carbide residue can be effectively improved.

[0081] In some embodiments, the diameter of the vibrating screen container can be 200 mm, and the remaining material is poured into two-thirds of the vibrating screen container.

[0082] In some embodiments, the operating parameters of the vibrating screen are: vertical amplitude of 6mm, gyration radius of 12.5mm, shaking frequency of 221 times / min, impact frequency of 147 times / min, motor power of 370W, motor speed of 2800r / min, and the operating time is set to 3 to 10 minutes.

[0083] In some embodiments, the solid block includes at least one of silicon carbide spheres, silicon carbide crystals, and silicon carbide spheres. The solid block of silicon carbide material can be used directly as a raw material without screening it, thus reducing the operation process.

[0084] In some embodiments, the diameter of the solid block is preferably 8 to 12 mm.

[0085] S200 performs a single sorting operation, adjusting the tilt angle of the bulk material container 11 and the air pressure of the air inlet pipe 122, fully opening the feeding device 2, starting the collection device 3, pouring the dispersed residual material into the feeding device 2, receiving the first product falling from the second discharge port 112, and collecting the second product blown to the first discharge port 111.

[0086] In some embodiments, the tilt angle of the bulk material container 11 is adjusted to a range of 47 to 63°, and the air pressure of the air inlet pipe 122 is adjusted to a range of 0.45 to 0.55 MPa.

[0087] It is worth noting that the tilt angle in the context refers to the angle between the bulk container 11 and the horizontal plane.

[0088] In some embodiments, the first product is silicon carbide fragments, and the second product is a mixture of silicon carbide residue and carbon powder.

[0089] S300 performs secondary sorting, readjusts the tilt angle of the bulk material container 11 and the air pressure of the air inlet pipe 122, partially opens the feeding device 2, and sets the collecting device 3 to either open or closed. The second product is poured into the feeding device 2, the third product falling from the second outlet 112 is received, and the fourth product blown to the first outlet 111 is collected.

[0090] In some embodiments, the tilt angle of the bulk material container 11 is adjusted again to a range of 25 to 37°, the air pressure of the air inlet pipe 122 is adjusted again to a range of 0.25 to 0.35 MPa, and the pin is slid to halfway open the material discharge channel 211.

[0091] In some embodiments, the third product is silicon carbide residue and the fourth product is carbon powder.

[0092] For S400 cleaning, place the first and third products in cleaning dishes respectively, wrap the fourth product with a filter screen and place it in the cleaning tank, turn on the ultrasonic cleaner, and repeat the water changing and cleaning process.

[0093] In some embodiments, the toner is encapsulated using a filter with a 0.5 mm pore size.

[0094] In some embodiments, during cleaning, the main air inlet valve of the ultrasonic cleaner is opened, the main air inlet pressure is set to 0.45-0.55 MPa, the nitrogen partial pressure is set to 0.01-0.02 MPa, the motor speed of the ultrasonic cleaner is adjusted to 800-1000 rad / h, the water flow rate in a single tank is controlled between 15.6-28.9 L / min, the frequency of the ultrasonic generator is set to 25-40 kHz, the power is 1200 W, the cleaning mode of the ultrasonic cleaner is set to overflow water replenishment mode, the forward rotation time of the motor during cleaning is 150-3000 s, and the reverse rotation time is 200-3500 s.

[0095] In some embodiments, the conditions for ending the cleaning step S400 can be:

[0096] S410, measure the turbidity of the liquid in the cleaning tank at the end of each cleaning cycle. The cleaning ends when the turbidity is lower than the set value, which is 25 ntu.

[0097] S500 drying: After cleaning, the first and third products are placed separately in a constant temperature drying oven. After drying, they are taken out and blown away the surface dust with a blower.

[0098] In some embodiments, the constant temperature drying oven is set to rapidly heat up to 300°C, maintain the temperature for 120 minutes, and then cool down to remove the first and third products.

[0099] It is worth noting that, in order to ensure the quality of the sorted products, the following steps can also be performed:

[0100] S600 performs a single sampling inspection, measuring the percentage of silicon carbide fragments in the first product. If the percentage of silicon carbide fragments is lower than the acceptable value, step S200 is repeated.

[0101] In some embodiments, the first product is considered qualified if the content of silicon carbide fragments exceeds 99.99%.

[0102] S700 Secondary sampling inspection measures the percentage of silicon carbide residue in the third product. If the percentage of silicon carbide residue is lower than the qualified value, step S300 is repeated.

[0103] In some embodiments, the third product is considered qualified if the content of silicon carbide residue exceeds 95%.

[0104] Under the same process conditions, crystal growth was carried out using normal silicon carbide raw materials, processed silicon carbide fragments, and processed silicon carbide residues as material sources, respectively, and the following comparison results were obtained:

[0105] (1) Crystals grown from normal silicon carbide raw materials have many microtubes in the center, and more “silicon droplets” accompanied by microtubes were observed when samples were taken.

[0106] (2) Crystals grown from treated silicon carbide fragments as raw material have a relatively thinner growth thickness in the same time period, which has certain performance disadvantages compared to crystals obtained from normal silicon carbide raw materials.

[0107] (3) The crystals grown from the treated silicon carbide residue have a lower microtube density and the number of microtubes accompanying the "silicon droplet" is significantly reduced, but the growth rate is reduced and the crystal edge condition is worse. Compared with the crystals obtained from the normal silicon carbide raw material, they have their own advantages and disadvantages.

[0108] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A method for recovering silicon carbide growth residue, characterized in that, The silicon carbide growth residue recovery device is used for recycling, and the recovery device includes: A blowing and separating device includes a bulk material container and a blowing and separating component. The bulk material container is inclined, with a first discharge port at its lower end and a second discharge port at its higher end. The blowing and separating component is disposed inside the bulk material container, located between the first discharge port and the second discharge port. The blowing and separating component includes an air inlet pipe, a distributor, and at least one air nozzle. The air nozzle is disposed on the distributor, and the air inlet pipe is connected to the distributor. The air nozzle is adapted to blow and separate residual material and cause at least a portion of the residual material to move towards the second discharge port. A feeding device, the feeding device being adapted to feed surplus material into the bulk material container, the surplus material being adapted to slide down along the bulk material container and pass through the blowing assembly; Collection device, the collection device being adapted to collect residual material that has moved to the second discharge port; The recycling method includes the following steps: S100 residual material processing: Take out the residual material from the furnace and pour it into the vibrating screen container. Place the vibrating screen container horizontally in the vibrating screen machine. Put solid blocks into the vibrating screen container. The solid blocks include at least one of silicon carbide spheres, silicon carbide crystals and silicon carbide crystal spheres. The diameter of the solid blocks is 8~12mm. Vibrate the screen machine to obtain dispersed residual material. In step S200, the bulk material container is tilted at an angle of 47-63°, and the air pressure of the inlet pipe is adjusted to 0.45-0.55 MPa. The feeding device is fully opened, and the collecting device is started to pour the dispersed residue into the feeding device. The first product falling from the second outlet is collected. The first product is silicon carbide fragments. The second product, which is a mixture of silicon carbide residue and carbon powder, is collected and dispersed to the first outlet. The percentage of silicon carbide fragments in the first product is measured. If the percentage of silicon carbide fragments is lower than the qualified value, step S200 is repeated. In S300, the second sorting process involves readjusting the tilt angle of the bulk material container to 25-37° and adjusting the air pressure range of the air inlet pipe to 0.25-0.35 MPa. The feeding device is partially opened, and the collection device is either open or closed. The second product is poured into the feeding device, which receives the third product falling from the second outlet. The third product is silicon carbide residue. The fourth product, which is carbon powder, is collected and blown to the first outlet. The percentage of silicon carbide residue in the third product is measured. If the percentage of silicon carbide residue is lower than the qualified value, step S300 is repeated. For S400 cleaning, place the first and third products in cleaning dishes respectively, wrap the fourth product with a 0.5mm pore size filter screen and place it in the cleaning tank, turn on the ultrasonic cleaner, and repeat the water changing cleaning. S500 drying: After cleaning, the first and third products are placed separately in a constant temperature drying oven. After drying, they are taken out and blown away the surface dust with a blower.

2. The method for recovering silicon carbide growth residue as described in claim 1, characterized in that: The blowing and separating device further includes an adjusting component connected to at least one end of the bulk material container, the adjusting component being adapted to change the height difference between the lower end and the higher end of the bulk material container.

3. The method for recovering silicon carbide growth residue as described in claim 2, characterized in that: The adjustment assembly includes an angle-adjusting pulley and a rotating shaft. The angle-adjusting pulley is connected to the lower end of the bulk material container, and the rotating shaft is rotatably connected to the higher end of the bulk material container. The angle-adjusting pulley is adapted to rotate the lower end of the bulk material container relative to the higher end of the bulk material container.

4. The method for recovering silicon carbide growth residue as described in claim 1, characterized in that: The distributor is rotatably disposed inside the bulk material container, and the air inlet pipe passes through the bulk material container and is connected to the distributor. The bulk material container is provided with a long strip-shaped bulk material cavity, and there are multiple air nozzles. The air nozzles are evenly distributed perpendicular to the length direction of the bulk material cavity, and the rotation direction of the distributor is perpendicular to the distribution direction of the air nozzles. The distance between the air nozzles and the bulk material container at the bottom is configured to be greater than the maximum movable height of the remaining material in the bulk material container.

5. The method for recovering silicon carbide growth residue as described in claim 1, characterized in that: The feeding device includes a feeding funnel and a flow regulator. The flow regulator is disposed on the feeding funnel and is adapted to control the feeding speed of the feeding funnel. The upper end of the bulk material container is provided with a feeding inlet, and the bottom of the feeding funnel is provided with a feeding channel. At least a portion of the feeding channel is adapted to extend into the bulk material container through the feeding inlet. The coefficient of friction of the inner wall of the feeding channel is 0.2 to 0.

5.

6. The method for recovering silicon carbide growth residue as described in claim 1, characterized in that: The collection device includes a collection channel, a fan, and a storage box. The first end of the collection channel faces the second discharge port, and the second end of the collection channel is connected to the storage box. The fan is adapted to draw in the residual material at the second discharge port through the first end of the collection channel and transport it to the storage box through the second end of the collection channel. The device also includes a frame, in which the blowing device is movably disposed. The feeding device and the first end of the collection channel both extend into the frame.

7. The method for recovering silicon carbide growth residue as described in claim 1, characterized in that: In step S100, the amplitude direction of the vibrating screen includes vertical amplitude and horizontal amplitude, and the solid block includes at least one of silicon carbide spheres, silicon carbide crystals and silicon carbide crystal spheres.

8. The method for recovering silicon carbide growth residue as described in claim 1, characterized in that, Step S400 includes step S410, measuring the turbidity of the liquid in the cleaning tank at the end of each cleaning, and ending the cleaning when the turbidity is lower than the set value.

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