Automatic production system for chemical purification of silicon material

Abstract

The invention discloses an automatic production system for chemical purification of a silicon material, which comprises a feeding unit, a chemical reaction unit, a purification unit, a discharging unit and a central control unit, and the feeding unit accurately controls the ratio of silicon powder to chlorine through a sensor and a conveying device; the reaction unit adopts a fluidized bed reactor for chlorination at specific temperature and pressure; the purification unit obtains high-purity chlorosilane through multi-stage distillation and adsorption; the central control unit receives data of each unit sensor, dynamically adjusts process parameters through feedback circulation, and realizes automatic optimization and control of the whole process; feeding is monitored in real time through the weighing sensor and the flowmeter, the central control unit is used for conducting feedback control on key parameters such as the feeding proportion, the reaction temperature and the pressure based on a PID control algorithm, and meanwhile real-time component data provided by the gas chromatographic analyzer and the impurity detector are combined; and stable control of key process parameters of the whole production process is realized.

Description

Technical Field

[0001] This invention relates to the field of silicon material purification technology, and in particular to an automated production system for the chemical purification of silicon materials. Background Technology

[0002] Chemical purification of silicon material is a key process in the preparation of high-purity polycrystalline silicon materials. Among them, the purification route based on chlorination (such as the modified Siemens process) is one of the mainstream technologies in industrial applications. Existing technologies usually use discrete reaction, distillation and purification equipment to achieve the conversion from metallurgical grade silicon to high-purity chlorosilanes in an intermittent or semi-continuous manner.

[0003] The aforementioned technologies suffer from unstable reaction efficiency and significant fluctuations in byproduct formation due to the reliance on manually set reactant ratios and the lack of real-time feedback. Furthermore, key parameters in the purification process (such as distillation column temperature and pressure) are typically controlled by preset programs, making it difficult to adaptively adjust to fluctuations in raw material impurity content, resulting in significant batch-to-batch variations in product purity. Moreover, the existing systems' units (feeding, reaction, and purification) often operate independently, lacking collaborative optimization, which not only increases energy consumption but also results in low levels of automation throughout the production process. These problems severely restrict further improvements in the preparation efficiency and product quality of high-purity silicon materials.

[0004] Therefore, in response to the problems mentioned above, this invention proposes an automated production system for the chemical purification of silicon materials. Summary of the Invention

[0005] To overcome the problems of low control precision, lag in parameter adjustment, and insufficient system integration in existing silicon chemical purification systems, this invention proposes an automated production system for silicon chemical purification. By introducing a multi-sensor real-time monitoring and feedback control mechanism, the system achieves adaptive optimization of the entire process from feeding to discharging, thereby ensuring the stability of the purification process and the consistency of the product.

[0006] The technical solution of this invention is: an automated production system for the chemical purification of silicon material, comprising: The feeding unit includes a silicon silo, a reagent storage tank, a conveying device, a weighing sensor, and a flow meter. The silicon silo has a capacity of 10-50 m³. 3 This reagent storage tank is used to store metallurgical-grade silicon powder with a particle size of 100-500μm and a purity of ≥98.5%. The tank has a capacity of 5-20m³. 3This device is used to store chlorine or hydrogen chloride gas with a purity ≥99.9%. The conveying device includes a screw conveyor and a pneumatic conveying pipeline. The screw conveyor has a conveying speed of 0.5-5 tons / hour, and the pneumatic conveying pipeline has a gas flow rate of 10-30 m / s. It is used to continuously feed silicon powder and reagents into the chemical reaction unit at a mass ratio of 1:1.2-1.5. The weighing sensor has an accuracy of ±0.1%, and the flow meter has an accuracy of ±0.5%. It is used to monitor the feed rate of silicon powder and reagents in real time and transmit the data to the central control unit. The chemical reaction unit includes a fluidized bed reactor, a heating device, a pressure control valve, and multiple sensors. The fluidized bed reactor has a volume of 5-20 m³. 3 This device is used to carry out the chlorination reaction of silicon material at a temperature range of 300℃ to 600℃ and a pressure range of 0.1-0.5MPa, with a reaction residence time of 30-120 minutes, to generate a chlorosilane mixture. The heating device is an electric heater or an induction heater to maintain the reaction temperature. The pressure control valve is used to regulate the internal pressure of the reactor. The multiple sensors include a temperature sensor, a pressure sensor, and a gas chromatograph to monitor the reaction status and gas composition in real time and transmit the data to the central control unit. The purification unit includes a multi-stage distillation column, an adsorption column, a condenser, a reboiler, and an impurity detector. The multi-stage distillation column consists of 3-5 stages connected in series and is used to fractionate a mixture of chlorosilanes to separate trichlorosilane (purity ≥99.99%) and silicon tetrachloride. The adsorption column has a diameter of 0.5-1.5 m and is filled with molecular sieves or activated carbon to remove heavy metal impurities. The condenser and reboiler are used to control condensation and evaporation during the distillation process. The impurity detector is a mass spectrometer used to monitor the impurity content of the purified product in real time and transmit the data to the central control unit. The discharge unit includes a product collection tank, a packaging device, and a quality testing instrument. The product collection tank is used to store high-purity silicon compounds, the packaging device is used to automatically package the products, and the quality testing instrument includes a laser particle size analyzer and a purity analyzer, which are used to detect the particle size and purity of the products online and transmit the data to the central control unit. The central control unit receives sensor data from the feeding unit, chemical reaction unit, purification unit, and discharge unit, and adjusts the feed ratio, reaction temperature, pressure, distillation column reflux ratio, and adsorption column flow rate in real time based on a preset algorithm. It also displays system status and alarm information and communicates with a remote monitoring center via wired or wireless network.

[0007] Preferably, the central control unit is also used to optimize operating parameters through a feedback control loop to ensure purification efficiency and quality, wherein the feedback control loop includes adjusting reaction conditions and purification parameters based on data from the gas chromatograph and impurity detector.

[0008] Preferably, the feeding unit further includes a pretreatment device, which includes a vibrating screen and a dryer. The vibrating screen has a mesh size of 100-400μm and a processing capacity of 2-8 tons / hour. The dryer is a cyclone dryer with an operating temperature of 80-150℃, which can reduce the moisture content of silicon powder from ≤500ppm to ≤50ppm. This configuration performs sieving and drying of silicon powder to remove large particles and moisture, ensuring uniform feeding.

[0009] Preferably, the fluidized bed reactor of the chemical reaction unit is equipped with a gas distribution plate and a catalyst bed. The gas distribution plate has an opening ratio of 30-50% and a pore size of 1-3 mm. The catalyst bed contains a copper or iron-based catalyst with a particle size of 0.5-2 mm and a bulk density of 0.8-1.2 g / cm³. 3 The filling amount is 20-40% of the reactor volume, which is used to promote the efficiency of chlorination reaction and increase the silicon conversion rate from 90% to ≥98%.

[0010] Preferably, the multi-stage distillation column of the purification unit adjusts the temperature of each section of the column according to the boiling point difference of the chlorosilane mixture. It has 5-10 temperature control zones arranged along the column height, each temperature control zone is independently controlled, with a temperature control accuracy of ±1℃ and a temperature gradient range of 50-200℃. This is used to automatically adjust the temperature of each section of the column according to the boiling point difference of the chlorosilane mixture, thereby optimizing the fractionation effect and increasing the product yield by 5-10%.

[0011] Preferably, the central control unit further includes a machine learning module, which is used to train a prediction model based on historical data to predict the reaction endpoint and purification effect in real time, and adjust operating parameters to improve product yield and purity.

[0012] Preferably, the system further includes an exhaust gas treatment unit, which includes a scrubbing tower, a burner, and an adsorption tower for treating the waste gas generated during the reaction and purification process. The scrubbing tower uses a 10-20% NaOH solution for circulating scrubbing, the burner is used to burn combustible gas at an operating temperature of 800-1200℃, the adsorption tower is used to capture residual impurities, and the central control unit is connected to the exhaust gas treatment unit to monitor the exhaust gas composition and adjust the treatment parameters.

[0013] Preferably, the scrubbing tower of the exhaust gas treatment unit also includes a pH sensor and an automatic dosing device. The pH sensor is used to monitor the acidity and alkalinity of the scrubbing liquid in real time. The pH sensor has a measurement range of 0-14 and an accuracy of ±0.1. The automatic dosing device is configured to automatically add alkaline solution according to the pH value to maintain neutralization efficiency.

[0014] Preferably, the quality detection instrument of the discharge unit also includes an X-ray fluorescence spectrometer, which is used to detect the content of trace elements in the product in real time and feed the data back to the central control unit to trigger the adjustment of purification parameters.

[0015] Preferably, the central control unit is connected to a cloud platform to enable remote data analysis and fault diagnosis, and sends real-time alarms via mobile terminals.

[0016] The beneficial effects of this invention are: 1. This invention monitors the feed in real time using a weighing sensor (accuracy ±0.1%) and a flow meter (accuracy ±0.5%). A central control unit, based on a PID control algorithm, provides feedback control of key parameters such as feed ratio, reaction temperature (temperature control accuracy ±2℃), and pressure (adjustment accuracy ±0.01MPa). Simultaneously, it combines real-time component data from a gas chromatograph (analysis cycle ≤5 minutes) and an impurity detector (detection limit down to ppb level) to achieve stable control of key process parameters throughout the entire production process. This solves the problems of low control accuracy, unstable reaction efficiency, and large batch-to-batch variations in product purity caused by reliance on manual settings and lack of real-time feedback in existing technologies.

[0017] 2. This invention uses a machine learning module (employing a random forest algorithm with a prediction accuracy of ≥95%) to analyze and learn from historical and real-time operational data. This enables the invention to predict reaction endpoints and purification effects in advance and proactively adjust operating parameters automatically, such as dynamically adjusting the reaction temperature (adjustment range ±10℃) and the distillation column reflux ratio (adjustment range ±10%). This data-driven predictive optimization strategy overcomes the shortcomings of existing systems, such as lagging parameter adjustments and inability to adapt to raw material fluctuations. As a result, the product yield is increased by 3-8%, and the purity is increased by 0.1-0.5%, significantly improving the intelligence level and adaptability of the production process.

[0018] 3. This invention connects the originally independent units such as feeding, reaction, purification, discharge and tail gas treatment into a collaborative whole, realizing data exchange and centralized optimization management throughout the entire process from raw material pretreatment to product packaging, thereby solving the problems of high energy consumption and low level of intelligence caused by the independent operation and lack of collaboration of each unit in the existing system. Attached Figure Description

[0019] Figure 1 The diagram shown is a schematic representation of the system framework of this invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, but 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] Please see Figure 1 This invention provides an embodiment of an automated production system for the chemical purification of silicon materials: In this embodiment, the feeding unit will be described in detail: The silicon material silo has a volume of 30m³. 3 The cone-shaped bottom structure is lined with an ultra-high molecular weight polyethylene wear-resistant layer. The bottom of the silo is equipped with a high-frequency vibrator with a frequency of 50Hz and an amplitude of 2mm, which can effectively prevent silicon powder bridging and ensure stable discharge.

[0022] The pretreatment unit includes a vibrating screen and a cyclone dryer. The vibrating screen has a mesh size of 200μm and a processing capacity of 5 tons / hour, which can ensure that the particle size of the raw material is uniformly distributed within the optimized range of 150-400μm. The drying system uses nitrogen gas with a dew point of -40°C as the medium. Through a synergistic process of first-stage pre-drying at 80°C, second-stage main drying at 120°C, and third-stage cooling to 40°C, the moisture content of silicon powder is stably reduced from the initial approximately 350ppm to below 30ppm.

[0023] The weighing sensor has a range of 0-5 tons and an accuracy class of 0.1; the flow meter has a range of 0-2000m³. 3 / h, accuracy ±0.5%, through real-time closed-loop adjustment of the central control unit; The conveying device includes a screw conveyor and a pneumatic conveying pipeline. The conveying speed of the screw conveyor is adjustable in the range of 0.5-5 tons / hour, while the pneumatic conveying pipeline maintains a gas flow rate of 10-30 m / s. Together, they ensure that the materials enter the chemical reaction unit in a preset proportion.

[0024] Workflow: Metallurgical-grade silicon powder stored in the silicon silo is first uniformly fed to the feed port under the action of a high-frequency vibrator at the bottom of the silo. Then, it is quantitatively fed into the pretreatment section by a screw conveyor. In the pretreatment stage, the silicon powder is first screened through a vibrating screen with a 200μm aperture to remove large particles and foreign matter that exceed the specifications. The qualified silicon powder after screening immediately enters a cyclone dryer, where it undergoes pre-drying at 80℃ to remove surface moisture, main drying at 120℃ for deep dehydration, and cooling at 40℃. Finally, the moisture content is stably controlled below 30ppm. The pretreated and dried silicon powder is then separated from chlorine gas with a purity of ≥99.9% from a reagent storage tank. In the metering stage, silicon powder is weighed in real time by a weighing sensor, while chlorine is metered by a thermal mass flow meter. The real-time data from both is immediately transmitted to the central control unit. The central control unit's built-in PID control algorithm compares the real-time data with the preset mass ratio of 1:1.2-1.5. Once a deviation is detected, an adjustment command is immediately output to dynamically adjust the motor speed of the screw conveyor and the opening of the regulating valve on the chlorine pipeline, so that the actual ratio is always maintained within the set range. The precisely proportioned silicon powder and chlorine are then synchronously transported to the subsequent fluidized bed reactor through a pneumatic conveying pipeline at a stable flow rate of 10-30 m / s.

[0025] In this embodiment, the chemical reaction unit is described in detail: The fluidized bed reactor is a vertical fluidized bed reactor with a volume of 12m³. 3 With a height-to-diameter ratio of 3:1, the reactor is equipped with multiple gas distribution plates with an opening rate of 40% and a pore size of 2mm, thereby ensuring uniform airflow distribution.

[0026] The heating device adopts a zoned induction heating method, with a total of 6 heating zones, each with a power of 80kW, and a total power of 480kW. Each heating zone is equipped with a type K thermocouple with a temperature measurement range of 0-800℃.

[0027] The pressure regulating valve is equipped with a piezoresistive pressure sensor with a range of 0-1 MPa and an accuracy of 0.5 class. The system maintains a reaction pressure of 0.3 MPa ± 0.02 MPa.

[0028] The gas chromatograph completes a full component analysis every 4 minutes and can monitor in real time. , , The detector sensitivity reaches 10 ppm for changes in the concentration of components.

[0029] Workflow: Precisely metered silicon powder and chlorine gas are first uniformly introduced into the fluidized bed reactor body through a gas distribution plate at the bottom of the reactor. The 40% open area and 2mm pore size of the distribution plate ensure uniform distribution of the reactant gas across the entire cross-section, keeping the silicon powder particles in a stable fluidized state. The reactants are then heated to a preset reaction temperature of 450℃. K-type thermocouples in each heating zone monitor the temperature in real time and feed the data back to the central control unit, ensuring the reaction temperature is precisely controlled within a fluctuation range of ±5℃. Simultaneously, the pressure regulating valve, guided by the pressure sensor signal, maintains the internal pressure of the reactor at a stable set value of 0.3MPa±0.02MPa, creating optimal thermodynamic conditions for the chlorination reaction. In the catalyst bed, a copper-based catalyst, accounting for 30% of the reactor volume and with a particle size of 0.5-2mm, significantly promotes the chemical reaction efficiency between silicon and chlorine, increasing the silicon conversion rate to over 98.5%, mainly producing a mixture of trichlorosilane and silicon tetrachloride. The gas chromatograph integrated at the reactor outlet performs full component analysis of the reaction products every 4 minutes, monitors the concentration changes of each chlorosilane component in real time, and transmits these key data to the central control unit in real time. Once the central control unit detects that the temperature, pressure or product components deviate from the set value, it immediately adjusts the heating power, the opening of the pressure regulating valve, and even the proportioning parameters of the preceding feed unit.

[0030] In this embodiment, the purification unit will be described in detail: The purification system uses a four-stage distillation column configuration in series, with the following parameters for each column: The first distillation column is 12m high with 35 trays and operates at 0.2MPa. It is mainly used to separate high-boiling-point impurities. The second distillation column is 10m high with 28 trays and operates at 0.15MPa. It is used to separate... The third distillation column is 8m high, has 25 trays, and operates at a pressure of 0.1MPa. It is used for purification. The fourth distillation column is 6m high, has 20 trays, and operates at a pressure of 0.08MPa. It is used for deep purification.

[0031] Eight temperature control zones are set along the height of each distillation column, using a jacketed heat exchange structure and heat transfer oil as the heat transfer medium. The temperature control accuracy is ±1℃, and the temperature gradient range is 80-180℃.

[0032] The adsorption unit uses two parallel adsorption columns, each 1.2m in diameter, filled with 13X molecular sieve to a height of 2m. The system is equipped with an automatic switching device that automatically switches to a standby column when one column becomes saturated, ensuring continuous operation.

[0033] The monitoring device uses a mass spectrometer, which completes a full elemental scan every 2 minutes, with a detection limit of 0.1 ppb, and can monitor the changes in the content of key impurities such as B, P, Fe, and Al in real time.

[0034] Workflow: The chlorosilane mixture from the chemical reaction unit first enters the first distillation column at an operating pressure of 0.2 MPa. Through its 35 trays and a temperature gradient control of 80-180℃, high-boiling-point impurities are effectively separated and removed. The preliminarily purified gaseous components then sequentially enter the second, third, and fourth distillation columns at operating pressures of 0.15 MPa, 0.1 MPa, and 0.08 MPa, respectively. In the second column, silicon tetrachloride is selectively separated; in the third column, trichlorosilane is predominantly purified; and in the fourth column, more precise temperature control (±1℃ accuracy) achieves deep purification of trichlorosilane. The product gas output from the distillation column system then enters the adsorption column. The column, filled with 13X molecular sieves, selectively adsorbs residual iron, aluminum, boron, and other metallic impurities at a flow rate of 0.5-2 m / s. When the mass spectrometer detects impurity penetration at the adsorption column outlet, the system automatically switches to the backup adsorption column and simultaneously regenerates the saturated column. Throughout the purification process, the condensers (heat exchange area 50-200 m²) of each distillation column are used for heat exchange. 2 The system and reboiler (heat load 200-800kW) work together to maintain stable condensation and evaporation efficiency. The mass spectrometer integrated in the pipeline performs a full element scan of the product every 2 minutes, transmitting the impurity content (detection limit down to 0.1ppb) data to the central control unit in real time. Based on this real-time data, the central control unit uses its built-in machine learning module to predict the product purity trend and dynamically adjusts the reflux ratio (adjustment range 1:5-1:20) and temperature gradient setpoint of each column. This ensures that a high-purity trichlorosilane product with a stable purity of ≥99.995% and a total metal impurity content of ≤0.8ppm is produced. At the same time, the tail gas from the purification process is introduced into the tail gas treatment unit for further processing.

[0035] In this embodiment, the discharge unit will be described in detail: The product collection tank has a storage space of 50m³. 3 There are three storage tanks, each equipped with a nitrogen sealing system to maintain a slightly positive pressure environment, thereby preventing product contamination.

[0036] The laser particle size analyzer has a measurement range of 0.1-1000μm and a repeatability error of ≤1%; the purity analyzer is based on Fourier transform infrared spectroscopy with a measurement accuracy of ±0.001%; ​​the X-ray fluorescence spectrometer can detect all elements from Na to U in the periodic table with a detection limit of 0.1ppm.

[0037] The packaging system uses a fully automatic ton bag packaging machine with a packaging speed of 8 tons / hour and a metering accuracy of ±0.2%.

[0038] Workflow: High-purity trichlorosilane from the purification unit first enters the product collection tank. A slightly positive pressure nitrogen environment is maintained inside the tank to prevent air backflow and product contamination. After stabilization within the collection tank, the product is continuously pumped to the detection system. The integrated laser particle size analyzer immediately analyzes the product's particle size distribution to ensure it meets preset specifications. Simultaneously, a purity analyzer and X-ray fluorescence spectrometer rapidly and accurately detect the product's bulk purity and trace element content such as iron, copper, and boron. All detection data is transmitted in real-time to the central control unit, which then updates the data with the production... The product quality is compared against established standards. If the product is qualified (e.g., purity ≥ 99.995%, total metal impurities ≤ 0.8 ppm), the packaging process is immediately triggered. A fully automatic ton-bag packaging machine measures and packages the product at an adjustable speed of 1-10 tons / hour, with packaging measurement accuracy controlled within ±0.2%. If any parameter deviates from the standard (e.g., purity fluctuation ≥ 0.001% or excessive levels of specific trace elements), the central control unit immediately sends a command to the purification unit to dynamically adjust parameters such as the reflux ratio of the distillation column or the flow rate of the adsorption column, forming feedback control. The packaged product undergoes a final quality audit before leaving the warehouse.

[0039] In this embodiment, a deep neural network algorithm is used for the machine learning module of the central control unit, with 32 nodes in the input layer, 3 hidden layers (64-128-64 nodes), and 8 nodes in the output layer. The training dataset contains 15,000 sets of historical data, and the model is updated quarterly.

[0040] In this embodiment, the exhaust gas treatment unit adopts a packed tower structure, with a tower height of 10m, a diameter of 2.5m, and a packing height of 4m. The scrubbing liquid is a 15% NaOH solution with a circulation flow rate of 50m³ / h. 3 / h. The pH control system accuracy is ±0.2, maintaining the pH at 11.5±0.3. The combustion tower operates at 1000℃, with a residence time of 2 seconds and a destruction efficiency ≥99.9%. The adsorption tower uses activated carbon fiber as the adsorbent material, with a specific surface area of ​​1500 m². 2 / g, with an adsorption capacity of ≥40% for organic matter.

[0041] Workflow: When mixed waste gas from the chemical reaction unit and purification unit is received, it is first introduced into the bottom of a 5-12m high scrubbing tower. There, it comes into countercurrent contact with a 10-20% NaOH scrubbing liquid sprayed from top to bottom in the packing layer. A pH sensor (measuring range 0-14, accuracy ±0.1) installed in the tower monitors the pH of the circulating liquid in real time and transmits the data to the central control unit. Based on this, the central control unit instructs the automatic dosing device (dosing accuracy ±1%) to replenish the alkali solution, stabilizing the pH of the scrubbing liquid within the optimal range of 10-12. This efficiently neutralizes acidic components such as hydrogen chloride and chlorine in the waste gas. After scrubbing and neutralization... The gas then enters a burner operating at 800-1200℃, where residual trace amounts of combustible chlorosilanes and organic impurities are completely thermally decomposed into stable substances such as silicon dioxide and hydrogen chloride. The flue gas produced after combustion then enters an adsorption tower filled with high specific surface area activated carbon adsorbent. Trace impurities such as residual heavy metals and incompletely burned organic matter in the flue gas are selectively adsorbed and retained. Finally, the exhaust gas after the above three-stage treatment has achieved a removal efficiency of ≥99.5% for harmful substances. After the monitoring system confirms that it meets the national emission standards, it is discharged into the atmosphere by an induced draft fan, thus completing the fully automated, efficient, and environmentally friendly purification process of the entire exhaust gas treatment.

[0042] This invention provides Embodiment 1: In this embodiment, the standard operating mode was used. The system was started according to the design parameters and underwent 72 hours of continuous production verification. The specific operating conditions were as follows: Its feed uses metallurgical grade silicon powder with a median particle size of 250μm and a moisture content strictly controlled at 35ppm, which is mixed with high-purity chlorine gas in an optimized mass ratio. The reaction process takes place in a fluidized bed reactor, with the core process parameters set at a temperature of 450℃ and a pressure of 0.3MPa, while maintaining sufficient reaction residence time to ensure conversion efficiency. The purification stage utilizes a multi-stage series distillation tower system, which achieves efficient separation of chlorosilane mixtures by precisely controlling the reflux ratio at 1:8.

[0043]

[0044] As shown in the table above, the silicon conversion rate reached a high level of 98.5%, indicating that the raw materials were fully utilized. The final trichlorosilane product had a purity of 99.995%. Regarding key quality indicators, the total amount of metallic impurities in the product was stably controlled at a low level of 0.8 ppm, and specific impurities such as boron and phosphorus, which have a serious impact on photovoltaic performance, were effectively removed. In terms of energy efficiency, the system also performed excellently, with the comprehensive energy consumption for producing one kilogram of high-purity silicon product optimized to 125 kWh, demonstrating its good economic operating characteristics while ensuring high-quality products.

[0045] This invention provides Embodiment 2: This embodiment employs a high-purity operating mode. The system has undergone specific optimization and adjustment of core process parameters with the goal of obtaining products with extreme purity. The specific operating conditions are as follows: The reaction temperature of the fluidized bed reactor was reduced to 420℃ to suppress the formation of side reactions. At the same time, the reflux ratio of the multi-stage distillation tower system in the purification unit was increased to 1:12 to enhance the separation efficiency. The material in the adsorption column was de-flowed to 0.8m / s to prolong the contact time and ensure deep removal of impurities.

[0046]

[0047] As shown in the table above, the purity of the final trichlorosilane product is increased to 99.998%. The total amount of metal impurities in the product is suppressed to 0.3 ppm, and the content of boron, which has a fatal impact on the electrical performance of semiconductor devices, is specifically reduced to a trace level of 0.05 ppb. This mode increases energy consumption, from 125 kWh / kg to 145 kWh / kg compared to the standard operating mode.

[0048] This invention provides a comparative example: This comparative example compares the present invention with two sets of conventional technologies to verify the parameters of the present invention. Comparative example 1 is a conventional DCS control system with key parameters set manually and offline quality analysis; comparative example 2 uses conventional PLC control with fixed parameters, and the experimental group is the present invention.

[0049] This comparative experiment used the same batch of metallurgical grade silicon powder with a purity of 98.8%. All three experimental groups were run continuously for 30 days, and samples were taken every 8 hours to test the results.

[0050]

[0051] As shown in the table above, the experimental group outperformed the two comparative groups in terms of control precision of key parameters such as temperature, pressure and feed ratio, and achieved zero unplanned shutdowns during 30 days of operation.

[0052]

[0053] As shown in the table above, the purity standard deviation of the products produced by the experimental group was as low as 0.01%, the metal content fluctuation was controlled within 5%, and the product qualification rate was as high as 99.8%, which fully demonstrates the great advantages of this invention in improving product quality consistency.

[0054]

[0055] As shown in the table above, the silicon conversion rate of the experimental group reached 98.5%, the energy consumption per unit product was reduced to 125 kWh / kg, and the frequency of manual intervention was significantly reduced to 0.5 times per shift, ultimately achieving an economic benefit of a 22% reduction in overall costs. Furthermore, the fact that the experimental group reduced the frequency of manual intervention to an extremely low 0.5 times per shift demonstrates that the system has achieved a nearly fully automated advanced operating mode, solving various shortcomings of existing technologies.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An automated production system for the chemical purification of silicon material, characterized in that, Including: The feeding unit includes a silicon silo, a reagent storage tank, a conveying device, a weighing sensor, and a flow meter. The silicon silo is used to store metallurgical grade silicon powder, and the reagent storage tank is used to store chlorine or hydrogen chloride gas. The conveying device includes a screw conveyor and a pneumatic conveying pipeline, which are used to continuously feed silicon powder and reagents into the chemical reaction unit in a preset ratio. The weighing sensor and flow meter are used to monitor the feed rate of silicon powder and reagents in real time and transmit the data to the central control unit. The chemical reaction unit includes a fluidized bed reactor, a heating device, a pressure control valve, and multiple sensors. The fluidized bed reactor is used to carry out the chlorination reaction of silicon material at a temperature range of 300°C to 600°C and a pressure range of 0.1-0.5 MPa to generate a chlorosilane mixture. The heating device is an electric heater or an induction heater used to maintain the reaction temperature. The pressure control valve is used to regulate the internal pressure of the reactor. The multiple sensors include a temperature sensor, a pressure sensor, and a gas chromatograph for real-time monitoring of the reaction status and gas composition, and transmitting the data to the central control unit. The purification unit includes a multi-stage distillation column, an adsorption column, a condenser, a reboiler, and an impurity detector. The multi-stage distillation column is connected in series and is used to fractionate a mixture of chlorosilanes to separate trichlorosilane and silicon tetrachloride. The adsorption column is filled with molecular sieves or activated carbon to remove heavy metal impurities. The condenser and reboiler are used to control condensation and evaporation during the distillation process. The impurity detector is a mass spectrometer used to monitor the impurity content of the purified product in real time and transmit the data to the central control unit. The discharge unit includes a product collection tank, a packaging device, and a quality testing instrument. The product collection tank is used to store high-purity silicon compounds, the packaging device is used to automatically package the products, and the quality testing instrument includes a laser particle size analyzer and a purity analyzer, which are used to detect the particle size and purity of the products and transmit the data to the central control unit. The central control unit receives sensor data from the feeding unit, chemical reaction unit, purification unit, and discharge unit, and adjusts the feed ratio, reaction temperature, pressure, distillation column reflux ratio, and adsorption column flow rate in real time based on a preset algorithm. It also displays system status and alarm information and communicates with a remote monitoring center via wired or wireless network.

2. The automated production system for chemical purification of silicon material according to claim 1, characterized in that: The central control unit is also used to optimize operating parameters through a feedback control loop to ensure purification efficiency and quality. The feedback control loop includes adjusting reaction conditions and purification parameters based on data from the gas chromatograph and impurity detector.

3. The automated production system for chemical purification of silicon material according to claim 2, characterized in that: The feeding unit also includes a pretreatment device, which includes a vibrating screen and a dryer for screening and drying the silicon powder to remove large particles and moisture.

4. The automated production system for chemical purification of silicon material according to claim 3, characterized in that: The fluidized bed reactor of the chemical reaction unit is equipped with a gas distribution plate and a catalyst bed. The gas distribution plate is used to uniformly distribute the reaction gas, and the catalyst bed contains a copper or iron-based catalyst to promote the efficiency of the chlorination reaction.

5. The automated production system for chemical purification of silicon material according to claim 4, characterized in that: The multi-stage distillation column of the purification unit adjusts the temperature of each section of the column according to the boiling point differences of the chlorosilane mixture.

6. The automated production system for chemical purification of silicon material according to claim 5, characterized in that: The central control unit also includes a machine learning module, which is used to train a prediction model based on historical data to predict the reaction endpoint and purification effect in real time, and adjust operating parameters to improve product yield and purity.

7. The automated production system for chemical purification of silicon material according to claim 6, characterized in that: The system also includes an exhaust gas treatment unit, which comprises a scrubbing tower, a burner, and an adsorption tower, for treating the waste gas generated during the reaction and purification process. The scrubbing tower uses alkaline solution to neutralize acidic gases, the burner is used to burn combustible gases, and the adsorption tower is used to capture residual impurities. The central control unit is connected to the exhaust gas treatment unit and monitors the exhaust gas composition and adjusts the treatment parameters.

8. The automated production system for chemical purification of silicon material according to claim 7, characterized in that: The scrubbing tower of the exhaust gas treatment unit also includes a pH sensor and an automatic dosing device. The pH sensor is used to monitor the acidity and alkalinity of the scrubbing liquid in real time, and the automatic dosing device is configured to automatically add alkaline solution according to the pH value to maintain neutralization efficiency.

9. The automated production system for chemical purification of silicon material according to claim 8, characterized in that: The quality detection instrument of the discharge unit also includes an X-ray fluorescence spectrometer, which is used to detect the content of trace elements in the product in real time and feed the data back to the central control unit to trigger the adjustment of purification parameters.

10. The automated production system for chemical purification of silicon material according to claim 9, characterized in that: The central control unit is connected to the cloud platform to enable remote data analysis and fault diagnosis, and sends real-time alarms via mobile terminals.

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