A polycrystalline silicon slag slurry treatment system

Abstract

This utility model relates to the technical field of impurity removal equipment in the polycrystalline silicon production process, and particularly to a polycrystalline silicon slurry treatment system, comprising: a mixing mechanism, a filtering mechanism, a washing mechanism, and a drying mechanism connected sequentially by pipelines; the mixing mechanism is used to mix cold hydrogenated slurry with fine silicon powder recovered from reduction tail gas, and a cooling mechanism is provided on the mixing mechanism to cool the mixed slurry and fine silicon powder to accelerate the flocculation and sedimentation of aluminum trichloride and fine silicon powder in the slurry; the filtering mechanism is used to filter the flocculated sediment from the mixing mechanism to obtain filter residue and clear liquid, and the filtering mechanism has an outlet for outputting clear liquid; the washing mechanism is used to receive the clear liquid generated by the filtering mechanism or store the washing liquid for circulating washing of the filter residue in the filtering mechanism; the drying mechanism is used to receive the washed filter residue and dry it. This utility model provides a new path with high efficiency, safety, and economy, realizing the optimization of the process flow and the effective utilization of resources.

Description

Technical Field

[0001] This utility model relates to the technical field of impurity removal equipment in the polycrystalline silicon production process, and in particular to a polycrystalline silicon slurry treatment system. Background Technology

[0002] During the production of polysilicon, a large amount of impurities are discharged along with the slurry formed by the reaction. In order to recycle the slurry, it is necessary to remove the solid impurities. Among the common impurity treatment methods, the cold hydrogenation process can remove solid impurities in the slurry to a certain extent, and the solid content can be reduced by dry dust removal technology.

[0003] However, in practice, this process has not fully solved the impurity problem, especially the removal effect on aluminum trichloride (AlCl3). Because AlCl3 is suspended in chlorosilane liquids and difficult to settle completely, traditional drum filtration or static sedimentation methods cannot completely remove these compounds and easily lead to blockages in pipelines and equipment in subsequent processes, increasing production and maintenance costs. Utility Model Content

[0004] In view of at least one of the above-mentioned technical problems, this utility model provides a polycrystalline silicon slag slurry treatment system; it utilizes fine silicon powder generated during the reduction process in the production process to improve the flocculation effect and enhance the impurity removal efficiency; by introducing the reaction between silicon powder and slag slurry, it promotes flocculation formation and significantly improves the removal rate of aluminum trichloride and other metal impurities; it not only effectively solves the shortcomings of conventional cold hydrogenation process, but also reduces production and maintenance costs, providing a more economical and efficient solution for polycrystalline silicon production, improving resource utilization, and optimizing and innovating the industry's production process.

[0005] According to a first aspect of the present invention, a polycrystalline silicon slag slurry treatment system is provided, comprising: The mixing mechanism, filtration mechanism, washing mechanism, and drying mechanism are connected sequentially by pipes. The mixing mechanism is used to mix the cold hydrogenation slag slurry with the fine silica powder recovered from the reduction tail gas. The mixing mechanism is equipped with a cooling mechanism to cool the mixed slag slurry and fine silica powder to accelerate the reaction of the slag slurry to form flocculent sediments. The filtration mechanism is used to filter the flocculated sediment of the mixing mechanism to obtain filter residue and clear liquid, and is provided with an outlet for outputting the clear liquid; The washing mechanism is used to receive the clear liquid produced by the filtration mechanism, or to store the washing liquid for circulating washing of the filter residue in the filtration mechanism. The drying mechanism is used to receive the washed filter residue and dry it.

[0006] In some embodiments of this utility model, the mixing mechanism includes a hollow tank and a stirring assembly disposed inside the tank. The tank is used to receive a predetermined proportion of slurry and fine silica powder. The stirring assembly is rotatably connected to the tank and is used to stir and mix the slurry and the fine silica powder.

[0007] In some embodiments of this utility model, the cooling mechanism is a jacket or a coil, and is evenly arranged around the outside of the tank.

[0008] In some embodiments of this utility model, a circulation pump is provided on the pipeline between the washing mechanism and the filtering mechanism. The circulation pump is used to continuously pump cleaning liquid into the filtering mechanism, so that the cleaning liquid circulates and washes the filter residue in the filtering mechanism.

[0009] In some embodiments of this utility model, the filter mechanism is provided with a backflushing mechanism that communicates with the interior of the filter mechanism, for blowing gas into the interior of the filter mechanism to remove residual impurities inside the filter mechanism.

[0010] In some embodiments of this utility model, the filtration mechanism is further provided with a differential pressure sensing component, which is used to sense the differential pressure value in the filtration mechanism in real time, and to control the mixing mechanism to stop and the washing mechanism to start when the set differential pressure value is reached.

[0011] In some embodiments of this utility model, each of the pipes is provided with a shut-off valve, which is used for the entry and exit of different materials in the pipe.

[0012] In some embodiments of this utility model, the cooling mechanism uses ethylene glycol or cooling water as the refrigerant, and the refrigerant temperature is -20°C to 10°C.

[0013] In some embodiments of this invention, the gas blown into the filter mechanism by the backflushing mechanism is nitrogen.

[0014] The beneficial effects of this invention are as follows: By integrating core mixing, cooling, filtering, washing, and drying mechanisms, a highly efficient impurity removal solution is achieved. In the underlying technology, the production process of polysilicon presents the challenge of removing impurities such as aluminum trichloride. Traditional methods typically rely on simple physical sedimentation or drum filtration, which have limited effectiveness and often lead to equipment clogging and high maintenance costs. To solve this problem, this system first uses a mixing mechanism to accurately mix the slurry with silicon powder in a precise ratio, allowing the adsorption capacity of the silicon powder to be fully utilized. A cooling mechanism located outside the tank appropriately cools the mixture to optimize particle contact, enhancing the flocculation effect of impurities and significantly improving the removal efficiency of aluminum trichloride. Unlike traditional methods, this system uses multi-stage filtration and washing steps. The filtration mechanism not only effectively separates the clear liquid from the mixture but also, in conjunction with the washing mechanism, uses a circulating pump and washing liquid to further remove residual impurities. The application of a drying mechanism dries the washed material, improving the purity of the final product. This not only improves the removal efficiency of aluminum trichloride but also reduces production and maintenance costs, enhancing process safety and economy. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the polycrystalline silicon slag slurry treatment system in an embodiment of this utility model; Figure 2 This is a schematic diagram of the washing structure and the filtration structure in the embodiments of this utility model.

[0017] Reference numerals: 1. Mixing mechanism; 2. Cooling mechanism; 3. Filtration mechanism; 4. Washing mechanism; 5. Drying mechanism. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] In the production of polysilicon, slurry is a byproduct, primarily composed of dichlorosilane, trichlorosilane, silicon tetrachloride, and various siloxanes (e.g., pentachlorosilane and hexachlorosilane). These compounds possess complex chemical properties and mix with various impurities during production, such as heavy metals like arsenic, molybdenum, and zinc, as well as non-metallic elements like phosphorus and boron. Among these impurities, titanium, aluminum, and silicon powder are present in the highest concentrations, potentially affecting product purity and equipment operation. To effectively remove these impurities, silicon powder is used as an adsorbent particulate material. The particle size of the silicon powder is selected between 0.5 and 10 μm to ensure good suspension in the chlorosilane liquid and sufficient contact with suspended impurities in the slurry. The chlorosilane, as the treatment medium, contains over 90% silicon tetrachloride, providing a stable chemical environment for the dispersion and adsorption of silicon powder. At lower impurity levels (<8 ppbw), this adsorption system demonstrates greater efficiency with silicon powder. By adjusting the concentration and particle size of the silicon powder, it helps to maximize the purity of the chlorosilane components without increasing impurities. This design not only improves the impurity removal effect but also optimizes the material processing method by selecting a suitable chemical environment, ensuring efficient management of the slurry in polysilicon production.

[0022] like Figures 1 to 2 The polysilicon slag treatment system shown includes: The mixing mechanism 1, the filtering mechanism 3, the washing mechanism 4, and the drying mechanism 5 are connected in sequence through pipes; Mixing mechanism 1 is used to mix cold hydrogenation slurry with fine silicon powder recovered from reduction tail gas. A cooling mechanism 2 is installed on mixing mechanism 1 to cool the mixed slurry and fine silicon powder, thereby accelerating the flocculation and sedimentation of aluminum trichloride and fine silicon powder in the slurry. The slurry and silicon powder are mixed in a predetermined ratio. The diameter of the silicon powder is 0.5-10 μm, suspended in liquid chlorosilane. In the production process of polycrystalline silicon, the slurry often contains difficult-to-remove metallic impurities, especially aluminum trichloride. These impurities are not only difficult to settle but also easily cause blockages in production pipelines and equipment, increasing maintenance and operating costs. This invention utilizes silicon powder as an adsorbent particulate material, which has good surface properties and adsorption capacity. Furthermore, the silicon powder is generated from the reduction process in other steps, thus saving production costs. The background is that traditional treatment methods often use other types of particulate materials, which may not be able to fully capture suspended impurities in the slurry. Silicon powder, due to its compatibility with polycrystalline silicon materials, exhibits excellent adsorption and chemical stability in the slurry. By mixing silicon powder with slurry in a certain proportion, silicon powder can effectively combine with impurities such as aluminum trichloride to form larger flocs, thereby significantly improving the sedimentation and filtration efficiency of impurities. Silicon powder not only enhances the effectiveness of the adsorption process, but also integrates with the polycrystalline silicon materials already in production, reducing the risk of foreign matter introduction.

[0023] By cooling the mixing mechanism 1, the internal temperature of the mixing mechanism 1 is reduced to the set temperature. Within the set temperature, the flocculation effect between the slurry and the silica powder is better.

[0024] In some embodiments of this invention, the ratio of slurry to silica powder is 3:1. Scientific experiments and engineering verification have shown that this ratio best improves the removal efficiency of impurities. By determining this ratio, the silica powder during the adsorption process can most effectively combine with impurities in the slurry, forming larger flocculent clumps, which helps promote the sedimentation and subsequent separation of impurities.

[0025] When materials are mixed inside mixing mechanism 1, other mechanisms do not operate. After the materials inside mixing mechanism 1 are evenly mixed, they are conveyed into filtering mechanism 3. This system optimizes the operation of mixing mechanism 1 by shutting down other mechanisms during the mixing stage, ensuring that the materials inside can be fully mixed in an isolated state. This increases the contact surface area between silica powder and slurry, thereby enhancing the flocculation effect and preventing subsequent processing in an incompletely mixed state, which could lead to equipment blockage or low processing efficiency. Once evenly mixed, the system conveys the uniformly mixed material to filtering mechanism 3 for further processing, ensuring the orderly and precise operation.

[0026] The filtration unit 3 is used to filter the flocculated sediment from the mixing unit 1 to obtain filter residue and clear liquid. The filtration unit 3 is equipped with an outlet for discharging the clear liquid. During the filtration process, the filtration unit 3 discharges the clear liquid continuously. In the operating phase of the filtration unit 3, when the material is being filtered, the system ensures that the material undergoes a pure filtration operation in an independent state. During this phase, only the clear liquid is discharged, ensuring that only the treated clear liquid is discharged under optimal conditions, preventing any possible mixing or cross-contamination. Compared to traditional filtration methods that may involve continuous flow disturbances, this approach significantly improves the cleanliness and efficiency of filtration by controlling the flow path and state during the filtration process, reduces the residue of impurities in the clear liquid, and enhances the overall reliability and economy of subsequent production processes.

[0027] The washing unit 4 receives the clean liquid produced by the filtration unit 3 or stores the cleaning liquid for circulating and washing the filter residue in the filtration unit 3. After the washing unit 4 is started, the cleaning liquid circulates between it and the filtration unit 3. During the washing process of the material in the filtration unit 3, other mechanisms are shut down to prevent any untreated material from entering or flowing between other processes, thus avoiding cross-contamination and other interference factors. The system provides a dedicated and closed environment, allowing the cleaning liquid to thoroughly wash the filtered material. This aims to optimize the washing effect and ensure that all impurities are effectively removed. The cleaning liquid circulates between the washing unit 4 and the filtration unit 3, carrying away impurities from the filtration unit 3. Traditional cleaning methods typically use a single washing process, failing to fully utilize cleaning resources or optimize the thorough removal of residues. This can lead to low cleaning efficiency and increased consumption of materials and water. This equipment is designed with a circulating cleaning liquid system. Multiple circulations of the cleaning liquid ensure that no residue accumulates within the system, allowing impurities to be thoroughly removed. Compared to the traditional single-use cleaning liquid method, this circulation not only improves the cleaning effect but also avoids resource waste.

[0028] In some embodiments of this utility model, the cleaning solution is 93% silicon tetrachloride. As a cleaning medium with chemical properties highly compatible with the polysilicon production process, silicon tetrachloride can effectively remove metallic impurities, especially aluminum trichloride (AlCl3), from slurry without adversely affecting equipment materials or the substances being treated. The purpose of using silicon tetrachloride as the cleaning solution is to ensure that the cleaning process is efficient yet gentle, thoroughly removing impurities while maintaining the surface integrity of the equipment and the safety of long-term operation. Compared with conventional cleaning solutions, silicon tetrachloride has superior impurity dissolving ability while reducing the risk of equipment corrosion and ensuring no by-product residues remain in the system.

[0029] Drying unit 5 is used to receive and dry the washed filter residue. After washing, the slurry is dried to remove aluminum trichloride.

[0030] In the system's workflow, a specific ratio of slurry and silicon powder is first mixed using mixing mechanism 1. The slurry and silicon powder are then injected into a tank according to a predetermined ratio, ensuring uniform mixing. Cooling mechanism 2 then operates, using a cooling system located outside the tank to cool the mixture inside. This process optimizes the contact surface between the slurry and silicon powder, resulting in a more significant flocculation effect. The cooled mixture is then conveyed to filtration mechanism 3. In filtration mechanism 3, the mixture is effectively filtered, with the clear liquid separated through the outlet, while the residual material is retained. When the material in filtration mechanism 3 reaches a set capacity, a washing mechanism 4 delivers stored washing liquid into filtration mechanism 3 to circulate and wash the remaining material, further removing impurities. The washed material is then conveyed to drying mechanism 5, which dries the washed material to ensure the purity of the final product. This series of processes ensures that the entire system efficiently and safely removes aluminum trichloride from the slurry, maintains good equipment operation, and optimizes resource utilization throughout the production process.

[0031] This system achieves a highly efficient impurity removal solution by integrating core mixing, cooling, filtering, washing, and drying mechanisms. The underlying technology involves removing impurities such as aluminum trichloride during polysilicon production. Traditional methods typically rely on simple physical sedimentation or drum filtration, which have limited effectiveness and often lead to equipment clogging and high maintenance costs. This system first uses a mixing mechanism 1 to accurately mix the slurry with silicon powder, maximizing the adsorption capacity of the silicon powder. A cooling mechanism 2, located outside the tank, appropriately cools the mixture to optimize particle contact, enhancing the flocculation effect of impurities and significantly improving the removal efficiency of aluminum trichloride. Unlike traditional methods, this system uses multi-stage filtration and washing steps. The filtration mechanism 3 not only effectively separates the clear liquid from the mixture but also, in conjunction with the washing mechanism 4, further removes residual impurities using a circulating pump and washing liquid. The drying mechanism 5 dries the washed material, improving the purity of the final product. This not only increases the removal efficiency of aluminum trichloride but also reduces production and maintenance costs, enhancing process safety and economy.

[0032] In the polysilicon production process, aluminum trichloride in the slurry is a difficult-to-remove impurity, especially since it is suspended in the liquid. Traditional sedimentation and simple mixing methods are insufficient for efficient treatment, often resulting in incomplete removal of impurities from the slurry and affecting the operational stability of subsequent processes. The mixing mechanism 1 includes a tank and a stirring component inside the tank. A predetermined ratio of slurry and fine silicon powder is input into the tank, and the stirring component agitates the slurry and fine silicon powder. The predetermined ratio of slurry and fine silicon powder input into the tank ensures precise control of the silicon powder dosage. Simultaneously, the stirring component ensures uniform and efficient mixing. The stirring process not only increases the contact area between the two materials but also enhances the reaction efficiency between the fine silicon powder and aluminum trichloride, thereby accelerating flocculation and sedimentation. It should be noted that the stirring component can take many forms, including paddle agitators, spiral agitators, threaded agitators, or other agitator types.

[0033] Traditional internal cooling methods can easily lead to uneven cooling of materials, resulting in unsatisfactory flocculation and potentially affecting subsequent processing steps. Cooling mechanism 2 is installed outside the tank in the form of a jacket or coil. The jacket or coil design ensures a more uniform cooling process without interfering with the material flow inside the tank, guaranteeing consistent temperature throughout the mixing batch. This external device allows for more flexible temperature control, reduces heat loss, and promotes a more complete reaction between aluminum trichloride and fine silica powder, improving settling speed and impurity removal efficiency. Compared to traditional built-in cooling mechanisms, this external cooling method not only reduces the impact on the internal structure of mixing mechanism 1, extending equipment lifespan, but also improves overall process performance by optimizing cooling efficiency, significantly increasing production stability and yield, ultimately achieving higher purity and quality.

[0034] During the filtration process of the mixed slurry, the filter unit 3 leaves residue on the filter layer. To remove this residue, the filter unit 3 is equipped with a backflushing mechanism, which blows air into the filter unit 3 to remove residual impurities. Because of the slurry residue left on the filter unit 3 during filtration, to improve the removal effect and ensure better precipitation of the clear liquid from the material entering the filter unit 3 from the mixing unit 1 in the next filtration, the filter unit 3 is backflushed after each filtration to remove the remaining slurry. After the backflushing mechanism finishes its work, the mixing unit 1 begins feeding. In the polysilicon production process, maintaining the efficient operation of the production line and avoiding unnecessary downtime are crucial to ensuring output and quality. Traditional production processes may lead to equipment interruptions due to untimely cleaning and maintenance, even affecting production efficiency and costs. To optimize this process, this equipment is designed with an intelligent workflow, in which the mixing unit 1 immediately begins feeding after the backflushing mechanism finishes its work. Through automated signal transmission, seamless connection between each step is ensured, reducing manual intervention and the time wasted on repeated settings.

[0035] To better control the material flow in and out of the filter unit 3 when it reaches the set volume, the filter unit 3 is also equipped with a differential pressure sensor. When the differential pressure sensor reaches the set differential pressure value, the mixing mechanism 1 stops feeding material into the filter unit 3 and starts the washing mechanism 4. Traditional filtration systems often lack real-time monitoring and automatic adjustment mechanisms, leading to easy filter clogging, reduced processing efficiency, and even frequent shutdowns for manual cleaning. To solve these problems, this system integrates a differential pressure sensor in the filter unit 3, which judges its operating status by monitoring the pressure difference across the filter in real time. When the differential pressure sensor detects the set differential pressure value, it means that the filter may be clogged or close to being clogged. At this time, the system automatically instructs the mixing mechanism 1 to stop feeding material into the filter unit 3 to prevent further clogging, and simultaneously starts the washing mechanism 4 instantly for cleaning. The purpose of this design is to maintain the continuity and efficiency of the filtration process through an automated monitoring and adjustment mechanism, avoiding delays and uncertainties caused by manual intervention.

[0036] In the production of polysilicon, the control of material flow between different processes is crucial, especially in systems involving multi-stage processing. The precise switching of material inflow and outflow in pipelines directly impacts the efficiency and stability of the entire process. Shut-off valves are installed on the pipelines to control the material flow between each mechanism. By precisely controlling the material flow between each mechanism, the shut-off valves can independently switch between different pipelines according to operational needs, enabling independent processing at different stages. For example, during mixing, the filtration, washing, or drying stages can be precisely isolated, ensuring the independence and precision of each process stage. This effectively avoids interference caused by uncontrolled material flow and ensures the orderly execution of mixing, filtration, washing, and drying. Compared to traditional methods, the configuration of shut-off valves not only improves the automation level of the process and reduces operational errors caused by human intervention, but also ensures the flexibility and safety of the entire system, thereby improving production efficiency, reducing operating costs, and achieving an economical and efficient production model.

[0037] The refrigerant used in cooling mechanism 2 is preferably a medium with relatively good chemical stability. In some embodiments of this utility model, the refrigerant is ethylene glycol or cooling water. Ethylene glycol is a stable cooling medium with excellent thermal conductivity. Its low freezing point allows it to maintain good fluidity even at low temperatures, ensuring uniform cooling of the mixture and effectively promoting the coagulation of impurity particles. Simultaneously, due to its chemical stability, ethylene glycol can prevent system corrosion and reduce maintenance requirements. Cooling water, as another optional refrigerant, is suitable for more common cooling requirements due to its affordability and ease of access. Compared to traditional cooling media that can easily impact the environment and equipment, cooling water is more environmentally friendly and reduces operating costs.

[0038] The refrigerant temperature ranges from -20°C to 10°C. This ensures that lead trichloride can be fully precipitated and bind to the adsorbed particulate material within this range. This precise temperature control makes the cooling process more targeted, achieving higher impurity coagulation and sedimentation efficiency. At low temperatures, the refrigerant maintains sufficient steady-state fluidity, allowing for uniform cooling of the entire mixture, thereby promoting rapid aggregation of impurity particles during the processing stage.

[0039] To prevent the gas in the backflushing mechanism from reacting with the contents of the filter mechanism 3, nitrogen is used in the backflushing mechanism. Nitrogen is chosen as the purging medium in the backflushing mechanism of this equipment. The reason for using nitrogen is its inertness, lack of moisture content, and inaction with materials used in polysilicon production, ensuring a dry internal environment free from other chemical interferences. The choice of nitrogen not only prevents corrosion problems but also significantly reduces the risk of oxidation, providing stable operating conditions for the filter mechanism 33.

[0040] Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A polysilicon slurry treatment system, characterized by, include: The mixing mechanism, filtration mechanism, washing mechanism, and drying mechanism are connected sequentially by pipes. The mixing mechanism is used to mix the cold hydrogenation slag slurry with the fine silica powder recovered from the reduction tail gas. The mixing mechanism is equipped with a cooling mechanism to cool the mixed slag slurry and fine silica powder to accelerate the reaction of the slag slurry to form flocculent sediments. The filtration mechanism is used to filter the flocculated sediment of the mixing mechanism to obtain filter residue and clear liquid, and is provided with an outlet for outputting the clear liquid; The washing mechanism is used to receive the clear liquid produced by the filtration mechanism, or to store the washing liquid for circulating washing of the filter residue in the filtration mechanism. The drying mechanism is used to receive the washed filter residue and dry it.

2. The polysilicon slurry processing system of claim 1, wherein, The mixing mechanism includes a hollow tank and a stirring assembly disposed inside the tank. The tank is used to receive a predetermined proportion of slurry and fine silica powder. The stirring assembly is rotatably connected to the tank and is used to stir and mix the slurry and the fine silica powder.

3. The polysilicon slurry processing system of claim 2, wherein, The cooling mechanism is a jacket or coil, and is evenly arranged around the outside of the tank.

4. The polysilicon slurry processing system of any one of claims 1-3, wherein, The cooling mechanism uses ethylene glycol or cooling water as the refrigerant, and the refrigerant temperature is -20℃ to 10℃.

5. The polysilicon slurry processing system of claim 1, wherein, A circulation pump is installed on the pipeline between the washing mechanism and the filtration mechanism. The circulation pump is used to continuously pump cleaning liquid into the filtration mechanism, so that the cleaning liquid can circulate and wash the filter residue in the filtration mechanism.

6. The polysilicon slurry processing system of claim 1, wherein, The filtration mechanism is equipped with a backflushing mechanism that communicates with the interior of the filtration mechanism, which is used to blow gas into the interior of the filtration mechanism to remove residual impurities inside the filtration mechanism.

7. The polysilicon slurry processing system of claim 6, wherein, The gas blown into the filter mechanism by the backflushing mechanism is nitrogen.

8. The polysilicon slurry processing system of claim 1, wherein, The filtration mechanism is also equipped with a differential pressure sensing component, which is used to sense the differential pressure value in the filtration mechanism in real time, and to control the mixing mechanism to stop and the washing mechanism to start when the set differential pressure value is reached.

9. The polysilicon slurry processing system of claim 1, wherein, Each of the aforementioned pipelines is equipped with a shut-off valve, which is used for the entry and exit of different materials in the pipeline.

Images