Silicon powder treatment process

Abstract

The invention relates to the technical field of powder granulation, and discloses a silicon powder treatment process. Silicon powder is put into a fluidized bed to be granulated and preliminarily heated, and the generated silicon powder is conveyed to a melting furnace through a connecting pipe under negative pressure; melting the silicon powder into silicon water through plasma heating in a melting furnace under the protection of argon; molten silicon molten by the melting furnace is guided into the granulating device through the connecting pipe, and the molten silicon is uniformly distributed and divided into multiple strands of trickles by stirring; high-pressure argon is sprayed to a silicon water outlet, so that the silicon water is cut off, and cooling and granulation are performed; and guiding and gathering the granulated silicon particles, and cutting and shaping the silicon particles with the size exceeding the standard when the silicon particles are not completely cured. According to the device, molten silicon water is shunted through the flow guide mechanism, so that in the process that the silicon water is blown out through high-pressure gas to be granulated, it is guaranteed that the diameter of the blown granulated particles is uniform, the diameter of the granulated particles is prevented from being too large, and powder granulation is more stable.

Description

Technical Field

[0001] This invention relates to the field of powder granulation technology, specifically a silicon powder processing process. Background Technology

[0002] Silicon powder processing technology is used to process silicon powder generated during silicon wafer processing to meet the needs of subsequent use as raw material for N-type cells in the photovoltaic industry, and to realize the recycling and reuse of silicon materials.

[0003] Patent application CN202510161156.6 discloses a dry granulation method and apparatus for silicon-containing powder or silicon-containing fine particles, relating to the field of powder granulation. The method includes: collecting silicon-containing powder or silicon-containing fine particles into a storage container to obtain silicon-containing material; quantitatively conveying the silicon-containing material to an elevator through a regulator; the elevator lifting the silicon-containing material from a first height to a second height; quantitatively conveying the silicon-containing material at the second height to a press through a feeder; the press performing dry pressing granulation on the silicon-containing material to output metallic silicon hard particles; screening the metallic silicon hard particles through a sieve to output finished silicon hard particles, and conveying the screened dust to the bottom of the elevator for recycling.

[0004] However, in conventional silicon powder processing, silicon powder is melted in an intermediate frequency furnace. Since the intermediate frequency furnace is made of silicon dioxide and borax, the silicon powder is subject to secondary contamination by the furnace lining during the melting process, resulting in a decrease in product purity. At the same time, traditional silicon powder processing usually involves pouring the molten silicon into a casting mold to cool and solidify before crushing. This crushing and processing process generates losses, leading to a decrease in recycling rate. Summary of the Invention

[0005] The purpose of this invention is to provide a silicon powder processing technology to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a silicon powder processing technology, comprising the following steps; S1. Silicon powder is fed into a fluidized bed for granulation and initial heating. The resulting silicon powder is transported to the melting furnace under negative pressure through a connecting pipe. S2. In a melting furnace, silicon powder is melted into molten silicon by plasma heating under argon protection. S3. The molten silicon in the melting furnace is introduced into the granulation device through the connecting pipe. The molten silicon is evenly distributed and divided into multiple fine streams by stirring. S4. High-pressure argon gas is injected into the outlet of the silicon water to interrupt the flow, cool and granulate the silicon water; S5. Guide and gather the granulated silicon particles, and cut and shape the silicon particles that exceed the size limit before they are completely solidified. S6. Collect silicon granules that meet the size requirements.

[0007] According to the above technical solution, the granulation device includes a shell 1, inside which a flow guiding mechanism is provided. The flow guiding mechanism includes a shell 2, the outer wall of which is fixedly connected to the inner wall of the shell 1. The outer wall of the shell 2 is fixedly connected to the bottom of the melting furnace through a connecting pipe. A flow distribution chamber is opened on the inner wall of the shell 2, and a flow guiding groove 2 is opened on the inner wall of the shell 2. A connecting hole is opened on the inner wall of the flow distribution chamber, and the connecting hole penetrates through the inner wall of the flow distribution chamber and communicates with the flow guiding groove 2. An air inlet is fixedly connected to the inner wall of the shell 2. The connecting hole is used to blow high-pressure gas into the flow guiding groove 2 to crush and granulate the molten silicon. The high-pressure gas injected into the flow distribution chamber through the air inlet is argon to prevent it from reacting with the molten silicon during the granulation process. The fluidized bed collects silicon powder through negative pressure and injects it into the melting furnace through the connecting pipe for melting by plasma heating. The furnace tube material inside the melting furnace is graphite.

[0008] According to the above technical solution, a flow guide block is fixedly connected to the inner wall of the second housing, and a flow divider is provided on the outer wall of the flow guide block. The flow divider is connected to the second flow guide and is used to guide the molten silicon water. The flow divider is used to divide the molten silicon water. The top of the flow divider is shaped like a horn mouth to guide the molten silicon water. The air inlet is used to fill the flow divider chamber with high-pressure protective gas. The flow divider chamber is used to guide the protective gas to the connection hole.

[0009] According to the above technical solution, a motor is fixedly connected to the top of the second housing, and a stirring blade is fixedly connected to the output end of the second motor. The bottom of the stirring blade rotates along the top of the guide block. The stirring blade is used to guide the molten silicon water so that the silicon water is evenly distributed on the top of the guide block. The bottom of the second housing is inclined inward to guide and gather the broken silicon particles.

[0010] According to the above technical solution, a flow guide groove is provided on the inner wall of the housing. The flow guide groove is an inclined circular groove used to guide the silicon particles and shape them. An inclined baffle is fixedly connected to the inner wall of the housing. The inclined baffle is used to intercept the silicon particles blown out by high-pressure gas and guide the silicon particles.

[0011] According to the above technical solution, a shaping plate is slidably connected to the inner wall of the shell, and a second inclined baffle is fixedly connected to the surface of the shaping plate. The second inclined baffle is used to intercept the silicon particles blown out by high-pressure gas and guide them into the first guide channel. A forming groove is opened at the bottom of the shaping plate. The position of the forming groove matches the position of the first guide channel. The forming groove is used to extrude and shape larger silicon particles.

[0012] According to the above technical solution, a motor is fixedly connected to the outer wall of the housing. The output end of the motor passes through the outer wall of the housing and is fixedly connected to the outer wall of the drive linkage. The outer wall of the drive linkage is rotatably connected to the inner wall of the housing via a rotating shaft. The outer wall of the drive linkage is rotatably connected to the inner wall of the molding plate via a rotating shaft. There are two sets of drive linkages. The two sets of drive linkages are equidistantly arrayed on the inner wall of the housing along the inclined direction of the molding plate. The two sets of drive linkages are connected by a connecting rod and rotate synchronously.

[0013] According to the above technical solution, the first guide channel is inclined downwards, and the inclined surface matches the bottom plane of the shaping plate, which is used to guide the silicon particles to the shaping plate, so that the shaping plate can shape the silicon particles through the forming groove.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a flow guiding mechanism to divert molten silicon water, allowing the silicon water to be blown out by high-pressure gas during granulation. This ensures that the diameter of the blown-out granules is uniform, preventing the granules from being too large and failing to meet size standards, thus making powder granulation more stable.

[0015] 2. The present invention uses a forming groove and a guide groove at the bottom of the forming plate to cut and shape silicon particles with larger diameters during the granulation process when the silicon particles are not solidified. This ensures that the diameter of the shaped silicon particles meets the size standard and avoids the further generation of silicon powder from the breakage of large-diameter silicon particles, which would otherwise result in losses.

[0016] 3. This invention uses negative pressure to feed materials into a fluidized bed and a melting furnace, and then directly heats and melts them. It can continuously granulate the silicon powder, which improves the production capacity of silicon powder granulation and avoids the loss caused by the crushing of large-diameter silicon particles and the generation of silicon powder again.

[0017] 4. The present invention guides the silicon particles through the second guide channel, so that the silicon particles remain aggregated during the collection and shaping process, and prevents the silicon particles from splashing during the collection process, increasing the equipment volume and collection cost, and effectively reducing the volume of the powder granulation equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the granulation device of the present invention; Figure 4 A cross-sectional view of the granulation apparatus of the present invention. Figure 1 ; Figure 5 A cross-sectional view of the granulation apparatus of the present invention. Figure 2; Figure 6 For the present invention Figure 5 Enlarged view of point A in the middle; Figure 7 A cross-sectional view of the flow guiding mechanism of the present invention. Figure 1 ; Figure 8 A cross-sectional view of the flow guiding mechanism of the present invention. Figure 2 ; Figure 9 A cross-sectional view of the flow guiding mechanism of the present invention. Figure 3 .

[0019] In the diagram: 100, granulation device; 101, melting furnace; 102, fluidized bed; 103, shell one; 104, motor one; 105, guide channel one; 106, inclined baffle one; 107, shaping plate; 108, forming tank; 109, inclined baffle two; 110, drive linkage; 200, guide mechanism; 201, shell two; 202, motor two; 203, stirring blade; 204, air inlet; 205, flow divider; 206, connecting hole; 207, guide block; 208, flow divider; 209, guide channel two. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0021] Example 1, please refer to Figures 1-6 The present invention provides a technical solution: a silicon powder processing technology, comprising the following steps; S1. Silicon powder is fed into fluidized bed 102 for granulation and initial heating. The resulting silicon powder is transported to melting furnace 101 through connecting pipe under negative pressure. S2. In the melting furnace 101, the silicon powder is melted into molten silicon by plasma heating under argon protection. S3. The molten silicon in the melting furnace 101 is introduced into the granulation device 100 through the connecting pipe. The molten silicon is evenly distributed and divided into multiple fine streams by stirring. S4. High-pressure argon gas is injected into the outlet of the silicon water to interrupt the flow, cool and granulate the silicon water; S5. Guide and gather the granulated silicon particles, and cut and shape the silicon particles that exceed the size limit before they are completely solidified. S6. Collect silicon granules that meet the size requirements; A silicon powder processing technology; In conventional silicon powder processing, silicon powder is melted in an intermediate frequency furnace. Since the intermediate frequency furnace is made of silicon dioxide and borax, the silicon powder is subject to secondary contamination by the furnace lining during melting, resulting in reduced product purity. Therefore, a melting furnace 101 is used to melt the silicon powder through plasma heating to form molten silicon for granulation. After granulation, a forming groove 108 and a guide groove 105 are set at the bottom of a shaping plate 107 to cut and shape larger silicon particles before they solidify during granulation. This ensures that the diameter of the shaped silicon particles meets the size standard, avoiding the breakage of large-diameter silicon particles and the generation of silicon powder again, which would lead to losses. After granulation in the fluidized bed 102, silicon powder is collected under negative pressure and injected into the melting furnace 101 through a connecting pipe for melting via plasma heating. The furnace tubes in the melting furnace 101 are made of graphite to prevent contamination of the molten silicon. The granulation device 100 includes a shell 103, with a guide channel 105 on the inner wall of the shell 103. The guide channel 105 is an inclined circular groove used to guide and shape the silicon particles. An inclined baffle 106 is fixedly connected to the inner wall of the shell 103 to intercept and guide the silicon particles blown out by high-pressure gas. A shaping plate 107 is slidably connected to the inner wall of the shell 103. An inclined baffle 109 is fixedly connected to the surface of the shaping plate 107 to intercept and guide the silicon particles blown out by high-pressure gas into the guide channel 105. A forming groove 10 is formed at the bottom of the shaping plate 107. 8. The forming groove 108 is positioned to match the guide groove 105. The forming groove 108 is used to extrude and shape larger silicon particles. A motor 104 is fixedly connected to the outer wall of the housing 103. The output end of the motor 104 passes through the outer wall of the housing 103 and is fixedly connected to the outer wall of the drive rod 110. The outer wall of the drive rod 110 is rotatably connected to the inner wall of the housing 103 via a rotating shaft. The outer wall of the drive rod 110 is rotatably connected to the inner wall of the shaping plate 107 via a rotating shaft. There are two sets of drive rods 110. The two sets of drive rods 110 are equidistantly arrayed on the inner wall of the housing 103 along the inclined direction of the shaping plate 107. The two sets of drive rods 110 are connected by a connecting rod and rotate synchronously. The guide groove 105 is inclined downwards, and the inclined surface matches the bottom plane of the shaping plate 107. It is used to guide the silicon particles to the shaping plate 107, so that the shaping plate 107 can shape the silicon particles through the forming groove 108. When a silicon powder processing device is put into use in a silicon powder processing process, silicon fragments to be granulated are fed into the fluidized bed 102 from the top cover for granulation. The silicon powder produced after granulation is introduced into the connecting pipe between the melting furnace 101 and the fluidized bed 102 under negative pressure during the operation of the fluidized bed 102, and guided into the melting furnace 101 through the connecting pipe. The silicon powder in the melting furnace 101 is heated and melted into molten silicon by plasma, and injected into the guiding mechanism 200 from the bottom of the melting furnace 101 through the connecting pipe for granulation by high-pressure gas. After granulation, the silicon particles are blown into the shell 103 and guided by the guiding channel 105, causing the silicon particles to roll in the inclined guiding channel 105. The splashed silicon particles pass through the inclined baffle 10. After being intercepted by the inner wall of the housing 103, the silicon particles are guided by the inclined baffle 106 and fall back into the guide channel 105. They are guided along the inclined direction of the guide channel 105 and roll naturally within the channel. The starting motor 104 acts as a power source to drive the drive linkage 110 to rotate on the inner wall of the housing 103. The two sets of drive linkages 110 are connected by a connecting rod, so that the drive linkage 110 drives the shaping plate 107 to keep parallel to the guide channel 105 and reciprocate on the inner wall of the housing 103. During the granulation process, when the silicon particles are not solidified, the larger diameter silicon particles are cut and shaped by the forming groove 108 in cooperation with the guide channel 105, so that the large diameter silicon particles are shaped into silicon particles with the appropriate diameter. During the granulation process, some silicon particles are intercepted by the inclined baffle 109 to prevent the larger diameter silicon particles from being directly sent to the outlet by the high-pressure gas.

[0022] Example 2, based on Example 1, please refer to... Figures 7-9 The present invention provides a technical solution: a flow guiding mechanism 200 is provided inside the housing 103; Traditional silicon powder processing typically involves pouring molten silicon into a casting mold to cool and solidify, followed by crushing. This crushing and processing process results in losses, leading to a reduced recycling rate. Therefore, a flow guiding mechanism 200 is installed to granulate the silicon using high-pressure gas and to divert the molten silicon. During the granulation process, the silicon is blown out by high-pressure gas, ensuring that the blown-out granules have a uniform diameter and preventing them from being too large and failing to meet size standards. This makes the powder granulation more stable. At the same time, the flow guiding channel 209 guides the silicon particles, keeping them clustered during the collection and shaping process and preventing splashing during collection, which would increase equipment size and collection costs, effectively reducing the size of the powder granulation equipment. The flow guiding mechanism 200 includes a second housing 201, the outer wall of which is fixedly connected to the inner wall of a first housing 103. The outer wall of the second housing 201 is fixedly connected to the bottom of the melting furnace 101 via a connecting pipe. A flow distribution chamber 205 and a flow guiding groove 209 are provided on the inner wall of the second housing 201. A connecting hole 206 is provided on the inner wall of the flow distribution chamber 205, penetrating the inner wall of the flow distribution chamber 205 and communicating with the flow guiding groove 209. An air inlet 204 is fixedly connected to the inner wall of the second housing 201. The connecting hole 206 is used to blow high-pressure gas into the flow guiding groove 209 to crush and granulate the molten silicon. The high-pressure gas injected into the flow distribution chamber 205 through the air inlet 204 is argon gas to prevent it from reacting with the molten silicon during the granulation process. A flow guiding block 207 is fixedly connected to the inner wall of the second housing 201. The outer wall of the guide block 207 is provided with a diversion groove 208, which is connected to the second guide groove 209. It is used to guide the molten silicon water. The diversion groove 208 is used to divert the molten silicon water. The top of the diversion groove 208 is shaped like a flared mouth to guide the molten silicon water. The air inlet 204 is used to fill the diversion chamber 205 with high-pressure protective gas. The diversion chamber 205 is used to guide the protective gas to the connection hole 206. The top of the second housing 201 is fixedly connected to the second motor 202. The output end of the second motor 202 is fixedly connected to the stirring blade 203. The bottom of the stirring blade 203 rotates along the top of the guide block 207. The stirring blade 203 is used to guide the molten silicon water so that the silicon water is evenly distributed on the top of the guide block 207. The bottom of the second housing 201 is inclined inward to guide and gather the broken silicon particles. After the silicon powder is heated and melted into molten silicon, it is guided into the housing 201 through a connecting pipe. The motor 202 is started, driving the stirring blade 203 to rotate on the inner wall of the housing 201, guiding the molten silicon evenly onto the top of the guide block 207. The molten silicon then enters the distribution channel 208 through the top flared opening, where it is divided and guided into the second guide channel 209. Simultaneously, high-pressure protective gas is passed through... The air inlet 204 injects gas into the distribution chamber 205 for distribution, allowing high-pressure gas to be blown through the connection hole 206 to the outlet of the distribution channel 208, interrupting the flow of silicon water and cooling it, thus granulating the silicon water. The granulated silicon particles are then blown into the second guide channel 209, where they are guided to converge towards the center of the second guide channel 209, preventing the silicon particles from being blown by the high-pressure gas and causing excessive agitation. The particles then fall into the first guide channel 105, where they are shaped.

[0023] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A silicon powder processing technology, characterized in that, Includes the following steps: S1. Silicon powder is fed into a fluidized bed (102) for granulation and initial heating. The resulting silicon powder is transported to the melting furnace (101) under negative pressure through a connecting pipe. S2. In the melting furnace (101), the silicon powder is melted into molten silicon by plasma heating under argon protection. S3. The molten silicon in the melting furnace (101) is introduced into the granulation device (100) through the connecting pipe. The molten silicon is evenly distributed and divided into multiple fine streams by stirring. S4. High-pressure argon gas is injected into the outlet of the silicon water to interrupt the flow, cool and granulate the silicon water; S5. Guide and gather the granulated silicon particles, and cut and shape the silicon particles that exceed the size limit before they are completely solidified. S6. Collect silicon granules that meet the size requirements.

2. The silicon powder processing technology according to claim 1, characterized in that: The granulation device (100) includes a first shell (103), inside which a flow guiding mechanism (200) is provided. The flow guiding mechanism (200) includes a second shell (201), the outer wall of which is fixedly connected to the inner wall of the first shell (103). The outer wall of the second shell (201) is fixedly connected to the bottom of the melting furnace (101) through a connecting pipe. A diversion chamber (205) is provided on the inner wall of the second shell (201). The inner wall of the second shell (201) is provided with a guide groove (209), and the inner wall of the diversion chamber (205) is provided with a connection hole (206). The connection hole (206) penetrates the inner wall of the diversion chamber (205) and communicates with the guide groove (209). The inner wall of the second shell (201) is fixedly connected with an air inlet (204). The connection hole (206) is used to blow high-pressure gas into the guide groove (209) to crush and granulate the molten silicon water.

3. The silicon powder processing technology according to claim 2, characterized in that: A flow guide block (207) is fixedly connected to the inner wall of the second housing (201). A flow divider (208) is provided on the outer wall of the flow guide block (207). The flow divider (208) is connected to the second flow guide (209) and is used to guide the molten silicon water. The flow divider (208) is used to divide the molten silicon water. The top of the flow divider (208) is shaped like a horn mouth and is used to guide the molten silicon water. The air inlet (204) is used to fill the high-pressure protective gas into the flow divider chamber (205). The flow divider chamber (205) is used to guide the protective gas to the connection hole (206).

4. The silicon powder processing technology according to claim 3, characterized in that: The top of the second housing (201) is fixedly connected to the second motor (202), and the output end of the second motor (202) is fixedly connected to the stirring blade (203). The bottom of the stirring blade (203) rotates along the top of the guide block (207). The stirring blade (203) is used to guide the molten silicon water so that the silicon water is evenly distributed on the top of the guide block (207). The bottom of the second housing (201) is inclined inward to guide and gather the broken silicon particles.

5. The silicon powder processing technology according to claim 2, characterized in that: The inner wall of the housing (103) is provided with a flow guide groove (105), which is an inclined circular groove used to guide the silicon particles and shape them. The inner wall of the housing (103) is fixedly connected with a slanted baffle (106), which is used to intercept the silicon particles blown out by high-pressure gas and guide them.

6. The silicon powder processing process according to claim 5, characterized in that: A shaping plate (107) is slidably connected to the inner wall of the housing (103). An inclined baffle (109) is fixedly connected to the surface of the shaping plate (107). The inclined baffle (109) is used to intercept the silicon particles blown out by high-pressure gas and guide them into the channel of the guide groove (105). A forming groove (108) is opened at the bottom of the shaping plate (107). The position of the forming groove (108) matches the position of the guide groove (105). The forming groove (108) is used to extrude and shape larger silicon particles.

7. A silicon powder processing process according to claim 6, characterized in that: A motor (104) is fixedly connected to the outer wall of the housing (103). The output end of the motor (104) passes through the outer wall of the housing (103) and is fixedly connected to the outer wall of the drive link (110). The outer wall of the drive link (110) is rotatably connected to the inner wall of the housing (103) through a rotating shaft. The outer wall of the drive link (110) is rotatably connected to the inner wall of the shaping plate (107) through a rotating shaft. There are two sets of drive links (110). The two sets of drive links (110) are equidistantly arrayed on the inner wall of the housing (103) along the inclined direction of the shaping plate (107). The two sets of drive links (110) are connected by a connecting rod and rotate synchronously.

8. A silicon powder processing process according to claim 5, characterized in that: The guide channel (105) is inclined downwards, and the inclined surface is matched with the bottom plane of the shaping plate (107) to guide the silicon particles to the shaping plate (107) so that the shaping plate (107) can shape the silicon particles through the forming groove (108).

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