A system and method for synergistically producing ultrafine powder with a dual-pulverizer

Abstract

This invention discloses a system and method for preparing ultrafine powder using a dual-milling process. The system includes a vertical mill pretreatment unit. The vertical mill pretreatment unit is used for pre-milling, drying, and removing impurities from the raw materials. An online intermediate material detection and diversion unit selectively returns intermediate powder to the vertical mill, sends it to an intelligent constant-flow homogenization chamber, or sends it to a bypass classification path based on parameters such as particle size, moisture content, specific surface area, temperature, impurities, and flow rate. The ultrafine ball mill fine grinding unit adopts a zoned milling structure. A deagglomeration and classification unit is used to deagglomerate and classify the powder exiting the mill. A coarse powder separation and recirculation unit recirculates true coarse powder, intermediate coarse powder, pseudo-coarse powder, and impurity-containing coarse powder to different processing paths according to the state of the coarse powder. A collaborative control unit coordinates and regulates the diversion, feeding, classification, and recirculation processes. This invention can reduce redundant milling and ineffective recirculation, improving the stability of the ultrafine powder preparation process and the consistency of the finished product quality.

Description

Technical Field

[0001] This invention relates to the field of powder processing and mineral material preparation technology, specifically to a system and method for preparing ultrafine powder through dual powder milling. Background Technology

[0002] Ultrafine powder materials are widely used in cement, concrete, mortar, mineral admixtures, industrial solid waste resource utilization, and related building materials. For mineral materials or industrial solid waste materials such as slag, steel slag, fly ash, limestone, tailings, and coal gangue, grinding can reduce particle size, improve particle size distribution, and to a certain extent enhance the powder's filling performance, dispersibility, and potential reactivity, thereby increasing its utilization value in building material systems or composite material systems. Therefore, how to stably, continuously, and with low energy consumption prepare ultrafine powders that meet the fineness requirements is an important technical problem in the fields of powder processing and solid waste resource utilization.

[0003] In existing powder preparation processes, commonly used grinding equipment includes vertical mills, ball mills, roller presses, classifiers, separators, deagglomeration equipment, dust collectors, and related conveying equipment. Among these, vertical mills are characterized by large throughput, strong drying capacity, high system integration, and suitability for processing moisture-containing raw materials, and are typically used for pre-grinding, drying, and preliminary classification of raw materials. Ball mills, on the other hand, are characterized by thorough grinding action, strong fine grinding capacity, and relatively stable product particle size distribution, and are typically suitable for medium-fine or ultrafine grinding. To accommodate the process characteristics of different grinding equipment, combined grinding systems that integrate vertical mills, roller presses, ball mills, and classifiers have emerged in the current technology.

[0004] For example, patent document CN118477717A discloses a grinding system involving the combined use of a roller press system, a vertical mill system, and a ball mill system. It describes how some material is fed into the ball mill system or returned to the original grinding system through methods such as material distribution and return. Another example is patent document CN103041906A, which discloses a slag micron powder grinding system and process. This system uses a roller press, an air classifier, a dynamic classifier, a ball mill, and a high-efficiency classifier to form a combined grinding process, and includes a steady-flow weighing bin, an iron remover, a metal detector, and a coarse powder return structure. These patent documents demonstrate that combined grinding, graded circulation, coarse powder return, and some online detection or impurity removal measures have already been applied in related technologies.

[0005] In a common combined grinding system, the raw material to be ground first enters a vertical mill for pretreatment. The vertical mill pre-grinds, dries, and initially removes impurities from the raw material to obtain intermediate powder. Subsequently, the intermediate powder is conveyed to a ball mill for further fine or ultrafine grinding. The ball mill output is then classified by a classifier. Qualified fine powder enters the finished product collection system, while unqualified coarse powder is returned to the ball mill or other grinding equipment for further grinding. This type of system can utilize the advantages of both vertical mills and ball mills to a certain extent, and has better process adaptability compared to single grinding equipment. However, existing technologies mainly focus on the combination of grinding equipment, classification and circulation, and coarse powder recirculation. There is still room for further improvement in the online comprehensive identification of the intermediate powder state and the multi-path quality and diversion.

[0006] In actual operation, the intermediate powder after pretreatment in a vertical mill typically enters the subsequent ball mill system via a fixed path, lacking online detection, identification, and differentiation of the intermediate powder's state. Due to differences in particle size, moisture content, hardness, grindability, and impurity content among minerals or solid wastes from different sources and batches, the intermediate powder output from a vertical mill may simultaneously contain coarse particles, powder with high moisture content, powder close to the finished product fineness, and abnormal powder containing metallic impurities or difficult-to-grind particles. If all these intermediate powders in different states directly enter the ball mill, it can easily cause fluctuations in the state of the material entering the ball mill, affecting the stable operation of the ball mill and grinding efficiency. Simultaneously, some intermediate powder that is already close to the target fineness may still enter the ball mill along with other materials for further grinding, leading to repeated grinding or over-grinding, increasing grinding energy consumption, and affecting the stability of the product particle size distribution.

[0007] Furthermore, ball mills are highly sensitive to fluctuations in the particle size, moisture content, and flow rate of the feed material. While existing combined grinding systems may include silos or buffer silos, such as the flow stabilization weighing silo mentioned in CN103041906A, these structures are typically used primarily for stabilizing feed or temporarily storing materials. There is still room for improvement in the homogenization, anti-segregation, fluidization, and state-based quality control of the powder. When the discharge flow rate or particle size of a vertical mill fluctuates, the feed rate and feed state of the ball mill also fluctuate, potentially leading to changes in the ball-to-material ratio within the mill, fluctuations in mill current, abnormal grinding noise, fluctuations in the fineness of the discharged powder, and an increase in the amount of recycled powder, thereby affecting the stability of the system's continuous operation. Meanwhile, during the preparation of ultrafine powder, as the particle size decreases and the specific surface area increases, fine powder particles are prone to agglomeration under the action of electrostatics, surface adsorption, moisture, or mechanical extrusion. Some fine powder particles that have reached or are close to the target fineness may exhibit a larger apparent particle size due to agglomeration. They may be misjudged as coarse powder during the classification process and returned to the ball mill for further grinding, thereby increasing the circulating load and ineffective grinding.

[0008] Existing methods for coarse powder recirculation are relatively simple, typically returning coarse powder separated by classifiers to the ball mill feed end or a fixed recirculation location. While patent documents such as CN118477717A, CN118477717B, and CN103041906A all involve material recirculation or coarse powder recirculation, they do not adequately differentiate the coarse powder based on its particle size, agglomeration state, impurity content, and recirculation flow rate. They also fail to further distinguish coarse powder into genuine coarse powder with significantly larger particle sizes, intermediate coarse powder with particle sizes slightly exceeding target requirements, pseudo-coarse powder with apparent larger particle sizes due to agglomeration, and impurity-containing coarse powder containing metallic impurities, difficult-to-grind particles, or abnormal particles, and then send them to corresponding grinding, deagglomeration, or impurity removal processes. Therefore, it is necessary to further improve the online detection and diversion of intermediate powder, the stable flow and homogenization of feed into the mill, the differentiated recirculation of coarse powder, and the multi-process collaborative control methods in dual-grinding systems. Summary of the Invention

[0009] This invention aims to address the problems existing in current combined grinding systems, such as lack of separation and diversion of intermediate powder, large fluctuations in feed material, uniform reflux of coarse powder, repeated grinding of pseudo-coarse powder, and insufficient collaborative control of multiple devices. It provides a system and method for the collaborative preparation of ultrafine powder using dual grinding mills. This system performs online detection and separation of intermediate powder pretreated by the vertical mill, stabilizes and homogenizes the powder before it enters the mill, deagglomerates and classifies the ball mill output, and identifies and recirculates the classified coarse powder through multiple paths. Simultaneously, a collaborative control unit coordinates and adjusts each process to reduce repeated grinding and ineffective reflux, minimize fluctuations in feed material flow, particle size, and moisture content, and improve grinding energy utilization efficiency and the quality stability of the finished ultrafine powder.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a system for the collaborative preparation of ultrafine powder using dual grinding mills, comprising a raw material conveying unit, a vertical mill pretreatment unit, an online intermediate material detection and diversion unit, an intelligent stable flow homogenization bin, an ultrafine ball mill fine grinding unit, a deagglomeration and classification unit, a coarse powder separation and reflux unit, a finished product collection unit, and a collaborative control unit. The raw material conveying unit, vertical mill pretreatment unit, online intermediate material detection and diversion unit, intelligent stable flow homogenization bin, ultrafine ball mill fine grinding unit, deagglomeration and classification unit, and finished product collection unit are connected sequentially along the material conveying direction. The discharge end of the conveying unit is connected to the feed end of the vertical mill pretreatment unit to convey the raw material to be ground to the vertical mill pretreatment unit; the vertical mill pretreatment unit is used to pre-grind, dry and remove impurities from the raw material to be ground, and output intermediate powder; the intermediate material online detection and diversion unit is set on the discharge side of the vertical mill pretreatment unit to detect at least two parameters of the intermediate powder, including particle size, moisture, specific surface area, temperature, metal impurity content and flow rate, and classifies the intermediate powder into abnormal intermediate material, normal intermediate material and intermediate material with near finished product fineness according to the detection results;

[0011] The intermediate material online detection and diversion unit is connected to the vertical mill pretreatment unit, the intelligent stable flow homogenization bin, and the bypass classifier through the return vertical mill channel, the channel leading to the intelligent stable flow homogenization bin, and the bypass classification channel, respectively. This allows abnormal intermediate material to return to the vertical mill pretreatment unit, normal intermediate material to enter the intelligent stable flow homogenization bin, and intermediate material with a fineness close to that of the finished product to enter the bypass classifier.

[0012] The discharge end of the intelligent constant flow homogenization bin is connected to the feed end of the ultrafine ball mill fine grinding unit. It is used to buffer, homogenize, prevent segregation, fluidize and meter the intermediate powder before it enters the ultrafine ball mill fine grinding unit. The ultrafine ball mill fine grinding unit includes an ultrafine ball mill. The ultrafine ball mill has a first grinding chamber, a second grinding chamber and a third grinding chamber arranged sequentially along the material flow direction. The first grinding chamber, the second grinding chamber and the third grinding chamber are separated from each other by a cavity partition structure. The particle size of the grinding balls in the first grinding chamber, the second grinding chamber and the third grinding chamber decreases step by step along the material flow direction.

[0013] The ultrafine ball mill is equipped with a primary return material inlet, a secondary return material inlet and a tertiary return material inlet. The primary return material inlet is connected to the first grinding chamber, the secondary return material inlet is connected to the second grinding chamber, and the tertiary return material inlet is connected to the third grinding chamber.

[0014] The deagglomeration and classification unit is located on the discharge side of the ultrafine ball mill fine grinding unit. It is used to deagglomerate, disperse and classify the powder discharged from the mill, and output qualified fine powder through the fine powder outlet and coarse powder through the coarse powder outlet. The fine powder outlet is connected to the finished product collection unit, and the coarse powder outlet is connected to the coarse powder separation and reflux unit.

[0015] The coarse powder separation and reflux unit is used to detect at least two parameters among the particle size, agglomeration degree, impurity content, and reflux flow rate of coarse powder, and classifies the coarse powder into true coarse powder, intermediate coarse powder, false coarse powder, and impurity-containing coarse powder according to the detection results. The coarse powder separation and reflux unit is connected to the first grinding chamber or primary return inlet through the first reflux channel, to the second grinding chamber or secondary return inlet through the second reflux channel, to the deagglomeration and classification unit through the third reflux channel, and to the vertical mill pretreatment unit or iron removal screening device through the fourth reflux channel, so that the true coarse powder is returned to the first grinding chamber or primary return inlet, the intermediate coarse powder is returned to the second grinding chamber or secondary return inlet, the false coarse powder is returned to the deagglomeration and classification unit, and the impurity-containing coarse powder is returned to the vertical mill pretreatment unit or iron removal screening device.

[0016] The collaborative control unit is communicatively or electrically connected to the intermediate material online detection and diversion unit, the intelligent steady flow homogenization bin, the ultrafine ball mill fine grinding unit, the deagglomeration and classification unit, and the coarse powder separation and reflux unit. It is used to collaboratively adjust the intermediate material diversion path, the feed rate into the mill, the classification parameters, and the coarse powder reflux path based on the intermediate powder detection results, the material level and discharge rate of the intelligent steady flow homogenization bin, the operating status of the ultrafine ball mill, the classification status of the deagglomeration and classification unit, the fineness of the finished product, and the coarse powder detection results.

[0017] Furthermore, the raw material conveying unit includes a feeding hopper, a raw material elevator, a raw material silo, and a weighing feeder connected in sequence; the discharge end of the feeding hopper is connected to the feed end of the raw material elevator, the discharge end of the raw material elevator is connected to the feed end of the raw material silo, the discharge end of the raw material silo is connected to the feed end of the weighing feeder, and the discharge end of the weighing feeder is connected to the feed end of the vertical mill pretreatment unit.

[0018] The vertical mill pretreatment unit includes a vertical mill, a hot air system, an iron removal screening device, and a vertical mill dust collector. The hot air system is connected to the vertical mill and is used to provide drying hot air to the vertical mill. The iron removal screening device is set on the discharge side of the vertical mill or in the material conveying channel and is used to remove metal impurities or abnormal particles from the intermediate powder. The vertical mill dust collector is connected to the dust-laden airflow outlet of the vertical mill and is used to collect the dust generated during the vertical mill pretreatment process.

[0019] Furthermore, the intermediate material online detection and diversion unit includes a sampling detection chamber, a particle size detector, a moisture detector, a specific surface area estimation unit, a temperature detector, a metal impurity detector, a flow detector, a multi-channel diversion valve, and a judgment controller. The feed end of the sampling detection chamber is connected to the discharge end of the vertical mill pretreatment unit, and the discharge end of the sampling detection chamber is connected to the feed end of the multi-channel diversion valve. The particle size detector, moisture detector, specific surface area estimation unit, temperature detector, metal impurity detector, and flow detector are respectively set to correspond to the sampling detection chamber and are respectively connected to the judgment controller via communication or electrical connection. The judgment controller is connected to the multi-channel diversion valve via communication or electrical connection and is used to control the diversion state of the multi-channel diversion valve based on at least two detection results from the particle size detector, moisture detector, specific surface area estimation unit, temperature detector, metal impurity detector, and flow detector.

[0020] The multi-channel diversion valve includes a return channel to the vertical mill, a channel to the intelligent flow homogenization chamber, and a bypass classification channel; the outlet of the return channel to the vertical mill is connected to the feed side or the circulating feed side of the vertical mill pretreatment unit; the outlet of the channel to the intelligent flow homogenization chamber is connected to the feed inlet of the intelligent flow homogenization chamber; and the outlet of the bypass classification channel is connected to the feed end of the bypass classifier.

[0021] When the controller determines that the intermediate powder is abnormal, it controls the multi-channel diversion valve to return the intermediate powder to the vertical mill pretreatment unit via the return vertical mill channel.

[0022] When the controller determines that the intermediate powder is normal intermediate material, it controls the multi-channel diversion valve to allow the intermediate powder to enter the intelligent flow homogenization silo through the channel leading to the intelligent flow homogenization silo.

[0023] When the controller determines that the intermediate powder is close to the fineness of the finished product, it controls the multi-channel diversion valve to allow the intermediate powder to enter the bypass classifier through the bypass grading channel.

[0024] Furthermore, the intelligent constant-flow homogenization silo includes a silo body, an inlet, an outlet, a level detector, a weighing detector, an in-silo fluidization device, an anti-segregation guiding structure, a variable frequency feeding device, and an outlet metering device. The inlet is located at the top of the silo body and is connected to the channel leading to the intelligent constant-flow homogenization silo from the intermediate material online detection and diversion unit. The outlet is located at the bottom of the silo body and is connected to the inlet end of the ultrafine ball mill grinding unit. The anti-segregation guiding structure is located inside the silo body, between the inlet and the outlet. The fluidization device is located at the bottom or lower-middle part of the silo to improve the flowability of powder in the silo; the level detector is located on the silo to detect the material level in the silo; the weighing detector is connected to the silo to detect the weight or weight change of the material in the silo; the frequency converter is located on the feed side and / or discharge side of the intelligent flow stabilization silo, and the discharge metering device is located at the discharge port. The frequency converter and the discharge metering device are used to regulate the flow rate of intermediate powder entering the silo and / or output from the silo to the ultrafine ball mill grinding unit.

[0025] Furthermore, the ultrafine ball mill refining unit includes an ultrafine ball mill, which includes a feed end, a first grinding chamber, a second grinding chamber, a third grinding chamber, a chamber partition structure, grinding balls, a primary return material inlet, a secondary return material inlet, a tertiary return material inlet, and a discharge end. The feed end is connected to the discharge port of the intelligent flow stabilization and homogenization chamber. The first, second, and third grinding chambers are sequentially arranged within the ultrafine ball mill along the material flow direction and are separated from each other by the chamber partition structure. The grinding ball particle size in the first grinding chamber is larger than that in the second grinding chamber, and the grinding ball particle size in the second grinding chamber is larger than that in the third grinding chamber. The primary return material inlet is connected to the first grinding chamber, the secondary return material inlet is connected to the second grinding chamber, and the tertiary return material inlet is connected to the third grinding chamber. The discharge end is connected to the feed end of the deagglomeration and classification unit.

[0026] The length of the first grinding chamber is 25% to 40% of the total effective grinding length of the ultrafine ball mill, and the particle size of the grinding balls in the first grinding chamber is 30 mm to 60 mm.

[0027] The length of the second grinding chamber is 30% to 45% of the total effective grinding length of the ultrafine ball mill, and the particle size of the grinding balls in the second grinding chamber is 15mm to 35mm.

[0028] The length of the third grinding chamber is 20% to 35% of the total effective grinding length of the ultrafine ball mill, and the particle size of the grinding balls in the third grinding chamber is 5mm to 20mm.

[0029] The primary return inlet is used to receive coarse powder, the secondary return inlet is used to receive intermediate coarse powder, and the tertiary return inlet is used to receive return powder with a particle size close to the qualified level but requiring shaping, dispersion or homogenization treatment.

[0030] Furthermore, the deagglomeration and classification unit includes a deagglomerator, a classification device, a high-efficiency classifier, a classification airflow regulating device, a fine powder outlet, and a coarse powder outlet. The feed end of the deagglomerator is connected to the discharge end of the ultrafine ball mill fine grinding unit for deagglomerating and dispersing the milled powder. The feed end of the classification device is connected to the discharge end of the deagglomerator, and the discharge end of the classification device is connected to the feed end of the high-efficiency classifier. The classification airflow regulating device is connected to the high-efficiency classifier for adjusting the classification airflow parameters of the high-efficiency classifier. The fine powder outlet is located on the fine powder output side of the high-efficiency classifier and is connected to the finished product collection unit. The coarse powder outlet is located on the coarse powder output side of the high-efficiency classifier and is connected to the coarse powder separation and reflux unit.

[0031] The finished product collection unit includes a dust collector, a finished product discharge valve, and a finished product silo. The inlet end of the dust collector is connected to the fine powder outlet of the deagglomeration and classification unit. The outlet end of the dust collector is connected to the finished product silo through the finished product discharge valve. The dust collector is used to collect qualified fine powder, and the finished product discharge valve is used to control the entry of qualified fine powder into the finished product silo.

[0032] Furthermore, the coarse powder separation and reflux unit includes a coarse powder temporary silo, a particle size detector, an agglomeration degree detector, an impurity content detector, a reflux flow rate detector, a multi-channel reflux valve, a first reflux channel, a second reflux channel, a third reflux channel, and a fourth reflux channel; the feed end of the coarse powder temporary silo is connected to the coarse powder outlet of the deagglomeration and classification unit; the particle size detector, agglomeration degree detector, impurity content detector, and reflux flow rate detector are respectively installed on the coarse powder temporary silo and / or the coarse powder conveying channel between the coarse powder temporary silo and the multi-channel reflux valve, and are respectively communicatively or electrically connected to the coordinating control unit; the multi-channel reflux valve... The feed end is connected to the discharge end of the coarse powder temporary silo; one end of the first reflux channel is connected to the first outlet of the multi-channel reflux valve, and the other end is connected to the first grinding chamber or primary return inlet of the ultrafine ball mill; one end of the second reflux channel is connected to the second outlet of the multi-channel reflux valve, and the other end is connected to the second grinding chamber or secondary return inlet of the ultrafine ball mill; one end of the third reflux channel is connected to the third outlet of the multi-channel reflux valve, and the other end is connected to the feed side of the deagglomeration and classification unit; one end of the fourth reflux channel is connected to the fourth outlet of the multi-channel reflux valve, and the other end is connected to the vertical mill pretreatment unit or iron removal screening device.

[0033] The coarse powder separation and reflux unit also includes a critical coarse powder re-judgment bypass. The critical coarse powder re-judgment bypass is used to perform short-term deagglomeration, secondary particle size detection and impurity verification on coarse powder that is near the judgment threshold or simultaneously meets the judgment conditions of two or more coarse powder types, and sends the re-judgment result to the collaborative control unit, which determines the coarse powder reflux path based on the re-judgment result.

[0034] Furthermore, the coarse powder separation and reflux unit may also include a critical coarse powder re-judgment bypass, which is set between the coarse powder temporary silo and the multi-channel reflux valve, or set on a bypass outlet side of the multi-channel reflux valve; the critical coarse powder re-judgment bypass includes a re-judgment inlet, a short-time deagglomeration device, a secondary particle size detection device, an impurity verification device, and a re-judgment outlet; when the coarse powder D90 is near the judgment threshold of true coarse powder, intermediate coarse powder, or false coarse powder, or when the coarse powder meets the judgment conditions of two or more coarse powder types at the same time, the coordinating control unit controls the multi-channel reflux valve or bypass switching valve to allow this part of the coarse powder to enter the critical coarse powder re-judgment bypass; After being processed by a short-time deagglomeration device, the coarse powder entering the critical coarse powder re-judgment bypass is detected by a secondary particle size detection device to determine the D90 after deagglomeration, and by an impurity verification device to determine the content of metal impurities or abnormal particles. The co-control unit re-determines the type of this part of coarse powder based on the re-judged D90, agglomeration degree K, and impurity content, and controls its entry into the first reflux channel, the second reflux channel, the third reflux channel, or the fourth reflux channel. In this way, coarse powder that is near the judgment threshold or whose type judgment is conflicting can be reconfirmed, avoiding the critical coarse powder from being mistakenly sent into mismatched grinding, deagglomeration, or impurity removal paths, and improving the accuracy of coarse powder separation and reflux.

[0035] Furthermore, the collaborative control unit is configured to determine the type of coarse powder based on the detection results of the particle size detector, agglomeration detector, impurity content detector, and reflux flow detector, and control the outlet state of the multi-channel reflux valve. When the coarse powder D90 is greater than 30 μm and the agglomeration degree K is less than 20%, the collaborative control unit determines the coarse powder as true coarse powder and controls the multi-channel reflux valve to return the true coarse powder to the first grinding chamber or the primary return inlet via the first reflux channel. When the coarse powder D90 is greater than 15 μm and less than or equal to 30 μm, and the agglomeration degree K is less than 20%, the collaborative control unit determines the coarse powder as intermediate coarse powder and controls the multi-channel reflux valve to return the intermediate coarse powder to the first grinding chamber or the primary return inlet via the first reflux channel. Coarse powder is returned to the second grinding chamber or the secondary return inlet via the second reflux channel; when the coarse powder D90 is greater than the target D90 threshold and the agglomeration degree K is greater than or equal to 20%, the co-control unit determines the coarse powder as pseudo-coarse powder and controls the multi-channel reflux valve to return the pseudo-coarse powder to the deagglomeration and classification unit via the third reflux channel; when the metal impurity content in the coarse powder is greater than 0.03wt% or the abnormal particle content is greater than 0.10wt%, the co-control unit determines the coarse powder as impurity-containing coarse powder and controls the multi-channel reflux valve to return the impurity-containing coarse powder to the vertical mill pretreatment unit or the iron removal screening device via the fourth reflux channel; wherein, the agglomeration degree K is determined according to the following formula:

[0036] K = / D90 before depolymerization × 100%.

[0037] Furthermore, the collaborative control unit includes a data acquisition module, a quality detection and analysis module, a process optimization module, a multi-objective decision-making module, an equipment collaborative control module, and an execution and feedback module. The data acquisition module is communicatively or electrically connected to the intermediate material online detection and diversion unit, the intelligent stable flow homogenization bin, the ultrafine ball mill grinding unit, the deagglomeration and classification unit, the coarse powder separation and reflux unit, and the finished product collection unit, respectively, for collecting intermediate powder detection parameters, homogenization bin material level and discharge rate, ball mill current and grinding noise, classifier operating parameters, finished product fineness, coarse powder detection parameters, and coarse powder reflux rate. The quality detection and analysis module is connected to the data acquisition module and is used to analyze the intermediate powder state, the state of the powder exiting the mill, and so on. The system includes modules for finished product fineness and coarse powder type; a process optimization module connected to the quality detection and analysis module to generate optimized schemes for intermediate powder diversion, mill feeding, ball mill reflux, classification adjustment, and coarse powder reflux; a multi-objective decision-making module connected to the process optimization module to determine control commands based on finished product fineness, system output, equipment load, reflux flow rate, and operational stability; an equipment collaborative control module connected to the multi-objective decision-making module, which outputs control signals to the multi-channel diversion valve, variable frequency feeder, discharge metering device, classification airflow adjustment device, and multi-channel reflux valve; and an execution and feedback module connected to the equipment collaborative control module to collect feedback data after control execution and return it to the data acquisition module.

[0038] The collaborative control unit includes a material status association control module, which generates an intermediate powder status label based on the intermediate powder detection results and associates the intermediate powder status label with the coarse powder detection results to correct the coarse powder return path.

[0039] Furthermore, the collaborative control unit also includes a material state association control module. This module generates an intermediate powder state label based on at least some parameters obtained from the intermediate powder particle size, moisture content, specific surface area, temperature, metal impurity content, and flow rate from the intermediate material online detection and diversion unit. It then associates the intermediate powder state label with the coarse powder detection results obtained from the subsequent coarse powder separation and reflux unit. The intermediate powder state label includes one or more of the following: coarse particle size label, high moisture content label, impurity risk label, agglomeration risk label, and flow rate fluctuation label. The collaborative control unit uses the intermediate powder state label, material residence time, mill feed rate, mill discharge time, and... Based on the coarse powder detection results, the coarse powder return path is corrected. When the intermediate powder has a coarse particle size label and the subsequent coarse powder has a large D90, this part of the coarse powder is preferentially returned to the first grinding chamber or the first-stage return inlet. When the intermediate powder has an agglomeration risk label and the subsequent coarse powder has a high agglomeration degree K, this part of the coarse powder is preferentially returned to the deagglomeration and classification unit. When the intermediate powder has an impurity risk label and the impurity content of the subsequent coarse powder increases, this part of the coarse powder is preferentially returned to the vertical mill pretreatment unit or the iron removal screening device. In this way, the state of the front-end intermediate powder and the back-end coarse powder return path can be linked across stages, reducing misjudgments caused by relying solely on the current coarse powder detection results, and improving the accuracy of coarse powder classification and return and the stability of system operation.

[0040] A method for preparing ultrafine powder using dual powder milling includes the following steps:

[0041] S1, the raw material to be ground is conveyed to the pretreatment unit of the vertical mill through the raw material conveying unit;

[0042] S2, the raw material to be ground is pre-ground, dried and impurity removed by the vertical mill pre-treatment unit to obtain intermediate powder;

[0043] S3, at least two parameters of intermediate powder are detected by the intermediate material online detection and diversion unit, including particle size, moisture, specific surface area, temperature, flow rate and impurities;

[0044] S4, the controller determines whether the intermediate powder is abnormal, normal, or close to the fineness of the finished product based on the detection results of the intermediate powder.

[0045] S5, when intermediate powder is determined to be abnormal intermediate material, the intermediate powder is returned to the vertical mill pretreatment unit through the return vertical mill channel via the multi-channel diversion valve.

[0046] S6, when the intermediate powder is determined to be normal intermediate material, the intermediate powder is directed to the intelligent flow homogenization silo through the multi-channel diversion valve. The intelligent flow homogenization silo then buffers, homogenizes, prevents segregation, fluidizes, and meters the intermediate powder.

[0047] S7, when the intermediate powder is determined to be intermediate material with a fineness close to that of the finished product, the intermediate powder is allowed to enter the bypass classifier through the bypass classification channel via the multi-channel diversion valve.

[0048] S8 transports the intermediate powder processed by the intelligent flow stabilization and homogenization bin to the ultrafine ball mill fine grinding unit, and performs zoned fine grinding through the first grinding chamber, second grinding chamber and third grinding chamber of the ultrafine ball mill to obtain the milled powder.

[0049] S9 conveys the powder exiting the mill to the deagglomeration and classification unit, where it is deagglomerated, dispersed and classified in sequence through a deagglomerator, a classification device and a high-efficiency classifier to obtain qualified fine powder and coarse powder;

[0050] S10, the qualified fine powder is conveyed to the finished product collection unit through the fine powder outlet, and collected through the dust collector, finished product unloading valve and finished product silo;

[0051] S11, the coarse powder is conveyed to the coarse powder separation and reflux unit through the coarse powder outlet, and the state of the coarse powder is detected by at least two of the particle size detector, agglomeration detector, impurity content detector and reflux flow detector;

[0052] S12, the co-control unit determines the type of coarse powder based on its state and controls the multi-channel reflux valve to select the coarse powder reflux path. The true coarse powder returns to the first grinding chamber or the primary return inlet through the first reflux channel, the intermediate coarse powder returns to the second grinding chamber or the secondary return inlet through the second reflux channel, the false coarse powder returns to the deagglomeration and classification unit through the third reflux channel, and the impurity-containing coarse powder returns to the vertical mill pretreatment unit or the iron removal screening device through the fourth reflux channel.

[0053] S13, through the collaborative control unit, adjusts the working status of the multi-channel diversion valve, frequency conversion feeding device, discharge metering device, grading airflow regulating device and multi-channel reflux valve in coordination based on the intermediate powder detection results, the material level and discharge rate of the intelligent stable flow homogenization silo, the operating status of the ultrafine ball mill, the grading status of the deagglomeration and grading unit, and the fineness and coarse powder detection results of the finished product.

[0054] Compared with the prior art, the beneficial effects of the present invention are:

[0055] 1. This invention, by setting up an online detection and diversion unit for intermediate materials after the pretreatment unit of the vertical mill, can detect parameters such as particle size, moisture content, specific surface area, temperature, metal impurity content, and flow rate of the intermediate powder. Based on the detection results, the intermediate powder is divided into abnormal intermediate material, normal intermediate material, and intermediate material close to the fineness of the finished product. Abnormal intermediate material can be returned to the pretreatment unit of the vertical mill via the return channel, normal intermediate material can enter the subsequent fine grinding process via the channel leading to the intelligent flow stabilization and homogenization bin, and intermediate material close to the fineness of the finished product can enter the bypass classifier via the bypass classification channel. Thus, it can avoid all intermediate powders in different states from entering the ball mill system, reduce the impact of abnormal materials with high moisture content, coarse particle size, or impurities on the subsequent fine grinding process, and reduce the probability of powder close to the fineness of the finished product being repeatedly ground.

[0056] 2. This invention sets up an intelligent flow stabilization and homogenization bin between the intermediate material online detection and diversion unit and the ultrafine ball mill fine grinding unit. Through the cooperation of the bin body, anti-segregation flow guiding structure, in-bin fluidization device, material level detector, weighing detector, frequency conversion feeding device and discharge metering device, the intermediate powder before entering the mill is buffered, homogenized, prevented from segregating, fluidized and metered. This structure can reduce the impact of vertical mill discharge flow rate, particle size and moisture fluctuations on the ultrafine ball mill, making the material state entering the ultrafine ball mill fine grinding unit more stable. This is conducive to stabilizing the ball mill current, grinding noise, in-mill material-to-ball ratio, discharge fineness and system powder return, and improving the stability of the continuous production process.

[0057] 3. The ultrafine ball mill of the present invention is provided with a first grinding chamber, a second grinding chamber, and a third grinding chamber, and forms a zoned grinding structure through a chamber partitioning structure. The particle size of the grinding balls in each grinding chamber decreases stepwise along the material flow direction, so that the grinding energy matches the particle size of the powder. At the same time, the primary return inlet, the secondary return inlet, and the tertiary return inlet are respectively connected to different grinding chambers, so that coarse powder, intermediate coarse powder, and return powder that is close to qualified but needs to be shaped, dispersed, or homogenized can enter the corresponding grinding area. This can avoid the problems of excessively long return grinding path, unreasonable energy distribution, and local over-grinding caused by all coarse powder returning to the ball mill feed end, and improve the targeted use of grinding energy.

[0058] 4. This invention sets up a deagglomeration and classification unit and a coarse powder separation and reflux unit after the ultrafine ball mill fine grinding unit. The powder exiting the mill is deagglomerated, dispersed, and classified by a deagglomerator, a classification device, a high-efficiency classifier, and a classification airflow regulating device. The state of the coarse powder is identified by a particle size detector, an agglomeration degree detector, an impurity content detector, and a reflux flow detector. For true coarse powder, intermediate coarse powder, pseudo coarse powder, and impurity-containing coarse powder, this invention sends them to different processing paths through the first reflux channel, the second reflux channel, the third reflux channel, and the fourth reflux channel, respectively. In particular, for pseudo coarse powder with an apparent particle size that is too large due to agglomeration, this invention can return it to the deagglomeration and classification unit instead of directly returning it to the ultrafine ball mill for repeated grinding, thereby reducing ineffective grinding and circulating load. For impurity-containing coarse powder, it can be returned to the vertical mill pretreatment unit or the iron removal screening device, thereby reducing the impact of abnormal particles on the fine grinding zone and the quality of the finished product.

[0059] 5. This invention uses a collaborative control unit to link and control the intermediate material online detection and diversion unit, the intelligent stable flow homogenization bin, the ultrafine ball mill fine grinding unit, the deagglomeration and classification unit, the coarse powder separation and reflux unit, and the finished product collection unit. It can coordinately adjust the multi-channel diversion valve, variable frequency feeder, discharge metering device, classification airflow regulating device, and multi-channel reflux valve based on the intermediate powder state, homogenization bin level and discharge rate, ball mill operating status, classification status, finished product fineness, and coarse powder detection results. Therefore, this invention effectively solves the problems of insufficient intermediate powder separation and diversion, large fluctuations in feed material, unified coarse powder reflux, repeated grinding of pseudo-coarse powder, and lack of coordinated control among multiple devices in existing combined grinding systems. It helps reduce ineffective grinding, decrease circulating load, improve the stability of finished product quality, and enhance the system's adaptability to different minerals or industrial solid waste materials such as slag, steel slag, fly ash, limestone, tailings, and coal gangue. Attached Figure Description

[0060] Figure 1 This is a flowchart of the overall process flow of the dual grinding system for the synergistic preparation of ultrafine powder according to the present invention.

[0061] Figure 2 This is a functional module structure diagram of the dual-milling synergistic ultrafine powder preparation system of the present invention;

[0062] Figure 3 This is a schematic diagram of the structure of the online detection and diversion unit for intermediate materials of the present invention;

[0063] Figure 4 This is a schematic diagram of the intelligent flow stabilization and equalization chamber of the present invention;

[0064] Figure 5 This is a schematic diagram of the structure of the ultrafine ball mill precision grinding unit of the present invention;

[0065] Figure 6This is a schematic diagram of the deagglomeration and classification unit and the coarse powder separation and reflux unit of the present invention;

[0066] Figure 7 This is a flowchart of the intermediate powder separation and diversion control method of the present invention;

[0067] Figure 8 This is a flowchart of the coarse powder separation and reflux and synergistic control method of the present invention. T1 to T7 are detailed sub-steps in the method of synergistic preparation of ultrafine powder of the present invention regarding the deagglomeration and classification of powder exiting the mill, coarse powder detection, coarse powder type determination and separation and reflux process, which mainly correspond to the subsequent processing flow in steps S8 to S13 of the method of the present invention.

[0068] In the diagram: 100 Raw material conveying unit, 101 Feeding hopper, 102 Raw material elevator, 103 Raw material silo, 104 Weighing feeder, 200 Vertical mill pretreatment unit, 201 Vertical mill, 202 Hot air system, 203 Iron removal and screening device, 206 Vertical mill dust collector, 300 Intermediate material online detection and diversion unit, 300B Bypass classifier, 301 Sampling and testing chamber, 302 Particle size detector, 303 Moisture detector, 304 Specific surface area estimation unit, 305 Temperature detection. 306 Metal impurity detector, 307 Flow detector, 308 Multi-channel diverter valve, 309 Judgment controller, 310 Return channel to vertical mill, 311 Channel to intelligent flow homogenization bin, 312 Bypass grading channel, 400 Intelligent flow homogenization bin, 401 Bin body, 402 Inlet, 403 Outlet, 404 Level detector, 405 Weighing detector, 406 In-bin fluidization device, 407 Anti-segregation flow guiding structure, 408 Variable frequency feeder, 409 Discharge meter Measuring device, 500 ultrafine ball mill fine grinding unit, 501 ultrafine ball mill, 502 feed end, 503 first grinding chamber, 504 second grinding chamber, 505 third grinding chamber, 506 chamber partition structure, 507 grinding balls, 508 primary return material inlet, 509 secondary return material inlet, 510 tertiary return material inlet, 511 discharge end, 600 deagglomeration and classification unit, 601 deagglomerator, 602 classification device, 603 high-efficiency classifier, 604 classification airflow regulating device, 605 fine powder outlet. 606 Coarse powder outlet, 700 Coarse powder separation and reflux unit, 701 Coarse powder temporary silo, 702 Particle size detector, 703 Agglomeration degree detector, 704 Impurity content detector, 705 Reflux flow detector, 706 Multi-channel reflux valve, 707 First reflux channel, 708 Second reflux channel, 709 Third reflux channel, 710 Fourth reflux channel, 800 Finished product collection unit, 801 Dust collector, 802 Finished product unloading valve, 803 Finished product silo, 900 Cooperative control unit. Detailed Implementation

[0069] The following combination Figures 1 to 8The technical solution of the present invention will be further described in detail below. It should be understood that the following content is used to illustrate the structural composition, connection relationships, operation process, and control method of the present invention, and is not intended to limit the scope of protection of the present invention. Without departing from the technical concept of the present invention, those skilled in the art can make adaptive adjustments to some structural forms, parameter ranges, and control strategies according to the type of raw materials, target fineness, equipment specifications, and production capacity.

[0070] In this invention, "connection" can be a direct connection or an indirect connection achieved through a conveying pipeline, conveying chute, elevator, screw conveyor, air conveying pipeline, valve, buffer silo or other powder conveying device; "communication connection or electrical connection" can be a wired connection or a wireless connection, or a data transmission and control connection achieved through a PLC, DCS, industrial computer, sensor acquisition module, actuator control module.

[0071] like Figure 1 and Figure 2 As shown, this invention provides a system for the collaborative preparation of ultrafine powder using dual grinding mills, comprising a raw material conveying unit 100, a vertical mill pretreatment unit 200, an online intermediate material detection and diversion unit 300, an intelligent stable flow homogenization chamber 400, an ultrafine ball mill fine grinding unit 500, a deagglomeration and classification unit 600, a coarse powder separation and reflux unit 700, a finished product collection unit 800, and a collaborative control unit 900; wherein the raw material conveying unit 100, the vertical mill pretreatment unit 200, the online intermediate material detection and diversion unit 300, the intelligent stable flow homogenization chamber 400, the ultrafine ball mill fine grinding unit 500, the deagglomeration and classification unit 600, and the finished product collection unit 800 are... 0 are connected sequentially along the main material flow direction; the coarse powder separation and reflux unit 700 is set on the coarse powder output side of the deagglomeration and classification unit 600, and is connected to the ultrafine ball mill fine grinding unit 500, the deagglomeration and classification unit 600, and the vertical mill pretreatment unit 200 or the iron removal screening device 203 respectively, for sending different types of coarse powder into different processing paths; the collaborative control unit 900 is communicatively or electrically connected to the intermediate material online detection and diversion unit 300, the intelligent stable flow homogenization bin 400, the ultrafine ball mill fine grinding unit 500, the deagglomeration and classification unit 600 and the coarse powder separation and reflux unit 700 respectively, for collecting system operation data and outputting control commands.

[0072] The basic operating process of this invention is as follows: The raw material to be ground first enters the vertical mill pretreatment unit 200 through the raw material conveying unit 100, where it is pre-ground, dried, and impurity removed to obtain intermediate powder. The intermediate powder enters the intermediate material online detection and diversion unit 300, where it is detected and divided into abnormal intermediate material, normal intermediate material, or intermediate material with a fineness close to that of the finished product. The normal intermediate material enters the intelligent stable flow homogenization bin 400 for buffering, homogenization, anti-segregation, fluidization, and metering feeding, and then enters the ultrafine ball mill fine grinding unit 500 for zoned fine grinding. The powder exiting the mill enters the deagglomeration and classification unit 600 for deagglomeration and classification. Qualified fine powder enters the finished product collection unit 800, and coarse powder enters the coarse powder classification and reflux unit 700. The coarse powder classification and reflux unit 700 classifies the coarse powder into true coarse powder, intermediate coarse powder, false coarse powder, and impurity-containing coarse powder according to the particle size, agglomeration degree, impurity content, and reflux flow rate, and sends them to the corresponding processing paths.

[0073] like Figure 1 As shown, the raw material conveying unit 100 includes a feeding hopper 101, a raw material elevator 102, a raw material bin 103, and a weighing feeder 104. The discharge end of the feeding hopper 101 is connected to the feed end of the raw material elevator 102, the discharge end of the raw material elevator 102 is connected to the feed end of the raw material bin 103, the discharge end of the raw material bin 103 is connected to the feed end of the weighing feeder 104, and the discharge end of the weighing feeder 104 is connected to the feed end of the vertical mill pretreatment unit 200. The raw material to be ground can be slag, steel slag, fly ash, or lime. The raw materials can be mineral materials such as stone, tailings, and coal gangue, or industrial solid waste materials, or a mixture of two or more of the above materials; the maximum particle size of the raw materials is preferably no more than 40 mm, more preferably no more than 25 mm; the moisture content of the raw materials is preferably no more than 12%, more preferably 3% to 8%; the temperature of the raw materials can be from room temperature to 80°C; the content of metal impurities in the raw materials is preferably no more than 0.10 wt%; the weighing feeder 104 is used to control the amount of raw materials fed into the vertical mill pretreatment unit 200, so that the raw material conveying remains continuous and stable.

[0074] The vertical mill pretreatment unit 200 includes a vertical mill 201, a hot air system 202, an iron removal screening device 203, and a vertical mill dust collector 206. The vertical mill 201 is used to pre-grind the raw material, transforming larger particles into intermediate powder suitable for subsequent testing and fine grinding. The hot air system 202 is connected to the vertical mill 201 and provides drying hot air to reduce the moisture content of the raw material. The iron removal screening device 203 is located on the discharge side of the vertical mill 201 or in the material conveying channel, and is used to remove metal impurities, large foreign objects, or difficult-to-grind abnormal particles from the intermediate powder. The vertical mill dust collector 206 is connected to the vertical mill 201. The dust-laden airflow outlet is connected to collect dust generated during the vertical mill pretreatment process. The intermediate powder processed by the vertical mill pretreatment unit 200 is preferably controlled as follows: D50 is 15μm~60μm, more preferably 20μm~45μm; D90 is 60μm~180μm, more preferably 80μm~150μm; moisture content is not greater than 1.5%, more preferably not greater than 1.0%; temperature is 45℃~105℃, more preferably 55℃~90℃; metal impurity content is not greater than 0.03wt%, more preferably not greater than 0.02wt%; and the flow rate fluctuation of the intermediate powder is preferably not greater than ±10%, more preferably not greater than ±5%.

[0075] like Figure 3 As shown, the intermediate material online detection and diversion unit 300 includes a sampling detection chamber 301, a particle size detector 302, a moisture detector 303, a specific surface area estimation unit 304, a temperature detector 305, a metal impurity detector 306, a flow rate detector 307, a multi-channel diversion valve 308, and a judgment controller 309. The feed end of the sampling detection chamber 301 is connected to the discharge end of the vertical mill pretreatment unit 200, and the discharge end of the sampling detection chamber 301 is connected to the feed end of the multi-channel diversion valve 308. The particle size detector 302, moisture detector 303, specific surface area estimation unit 304, temperature detector 305, metal impurity detector 306, and flow rate detector 307 are respectively set corresponding to the sampling detection chamber 301, and are respectively connected to the judgment controller 309 through communication or electrical connection. The judgment controller 309 is connected to the multi-channel diversion valve 308 through communication or electrical connection, and is used to control the diversion state of the multi-channel diversion valve 308 according to the detection results.

[0076] The particle size detector 302 can be an online laser particle size analyzer, a dynamic image particle size analyzer, an online sieve residue estimation device, or a bypass automatic sampling particle size detection device to obtain the D50, D90, or sieve residue trend of the intermediate powder; the moisture detector 303 can be a microwave moisture analyzer, an infrared moisture analyzer, or an automatic sampling drying detection device to obtain the moisture content of the intermediate powder; the specific surface area estimation unit 304 can estimate the specific surface area of ​​the intermediate powder based on particle size distribution, density, flow rate, and historical calibration models, and can also perform periodic correction with offline specific surface area detection results; the temperature detector 305 is used to detect the temperature of the intermediate powder; the metal impurity detector 306 can be a metal detector, a magnetic detector, or an online iron removal feedback detection device; the flow rate detector 307 can be a weighing flow meter, a plate flow meter, a belt scale, or a powder mass flow meter.

[0077] The multi-channel diversion valve 308 includes a return channel 310 to the vertical mill, a channel 311 leading to the intelligent flow homogenization chamber, and a bypass grading channel 312; the outlet of the return channel 310 is connected to the feed side or the circulating feed side of the vertical mill pretreatment unit 200; the outlet of the channel 311 leading to the intelligent flow homogenization chamber is connected to the feed inlet 402 of the intelligent flow homogenization chamber 400; and the outlet of the bypass grading channel 312 is connected to the feed end of the bypass classifier 300B.

[0078] The bypass classifier 300B can be an air classifier, a dynamic classifier, a screening and grading device, or a combination of the above devices. It is used to further classify intermediate powder that is close to the fineness of the finished product entering through the bypass grading channel 312. The bypass classifier 300B can be equipped with a fine powder outlet and a coarse powder outlet. The fine powder outlet is connected to the finished product collection unit 800 or the finished product conveying pipeline to directly send the powder that meets the fineness requirements of the finished product into the finished product collection process. The coarse powder outlet is connected to the intelligent flow stabilization and homogenization bin 400, the return vertical mill channel 310, or the vertical mill pretreatment unit 200 to send the powder that does not meet the fineness requirements of the finished product into the subsequent fine grinding process or return it to the vertical mill pretreatment process. In this way, it can avoid all intermediate powder that is close to the fineness of the finished product from entering the ultrafine ball mill fine grinding unit 500 and causing repeated grinding.

[0079] The controller 309 performs flow control based on the intermediate powder detection results. When the intermediate powder meets any of the following conditions: D90 greater than 180μm, moisture content greater than 1.5%, temperature greater than 110℃, metal impurity content greater than 0.03wt%, or instantaneous flow fluctuation exceeding ±15% of the set feed rate, the intermediate powder is identified as abnormal. The multi-channel flow divider 308 is then controlled to return the intermediate powder to the vertical mill pretreatment unit 200 via the return vertical mill channel 310 for re-pre-grinding, drying, or impurity removal. When the intermediate powder meets the following conditions: D90 between 60μm and 180μm, moisture content not greater than 1.5%, temperature between 45℃ and 105℃, metal impurity content not greater than 0.03wt%, and flow fluctuation not greater than ±10%, the intermediate powder is identified as abnormal. For normal intermediate material, the multi-channel diversion valve 308 is controlled to allow the intermediate powder to enter the intelligent stable flow homogenization chamber 400 through the channel 311 leading to the intelligent stable flow homogenization chamber. When the intermediate powder meets the following requirements: D90 not greater than 45μm, 45μm sieve residue not greater than 3.0%, specific surface area not less than 600m² / kg, and moisture not greater than 1.0%, the intermediate powder is determined to be intermediate material with a fineness close to that of the finished product. The multi-channel diversion valve 308 is then controlled to allow the intermediate powder to enter the bypass classifier 300B through the bypass classification channel 312. The qualified powder obtained by the bypass classifier 300B can enter the finished product collection unit 800 or the finished product conveying pipeline. The powder that does not meet the requirements can be returned to the vertical mill pretreatment unit 200 or enter the intelligent stable flow homogenization chamber 400 for ball mill fine grinding.

[0080] like Figure 4 As shown, the intelligent flow stabilization homogenization bin 400 includes a bin body 401, a feed inlet 402, a discharge outlet 403, a material level detector 404, a weighing detector 405, an in-bin fluidization device 406, an anti-segregation flow guiding structure 407, a variable frequency feeding device 408, and a discharge metering device 409. The feed inlet 402 is located at the upper part of the bin body 401 and is connected to the channel 311 leading to the intelligent flow stabilization homogenization bin, used to receive normal intermediate materials. The discharge outlet 403 is located at the lower part of the bin body 401 and is connected to the feed end 502 of the ultrafine ball mill grinding unit 500. The bin body 401 is used to temporarily store and buffer intermediate powder materials, so that the flow fluctuation of the intermediate material online detection and diversion unit 300 is reduced.

[0081] An anti-segregation flow guiding structure 407 is installed inside the silo body 401 and located between the inlet 402 and the outlet 403. The anti-segregation flow guiding structure 407 can be a baffle plate, a guide plate, a conical distributor, a central deceleration tube, a multi-layer dispersion plate, or a combination of the above structures. It is used to change the falling path of the powder and reduce stratification and segregation caused by differences in particle size, density, or falling velocity between coarse and fine particles. An in-silo fluidization device 406 is installed in the lower or lower-middle part of the silo body 401 and can be a fluidization duct, a fluidization plate, or a gas spray device. The fluidizing device 406 is used to introduce low-pressure gas into the silo body 401, so that the powder inside the silo is in a flowable state, reducing bridging, arching, wall adhesion and blockage; the fluidizing air pressure inside the silo is preferably 3kPa to 12kPa, more preferably 5kPa to 8kPa; the fluidizing air volume is preferably 0.03Nm³ / min·m² to 0.15Nm³ / min·m², more preferably 0.05Nm³ / min·m² to 0.10Nm³ / min·m².

[0082] The level detector 404 is used to detect the material level inside the silo 401, and the weighing detector 405 is used to detect the weight or weight change of the material inside the silo 401. The level detection cycle is preferably 1s to 10s, more preferably 1s to 5s; the weighing detection cycle is preferably 1s to 10s, more preferably 1s to 5s; the material level inside the silo is preferably controlled at 30% to 85%, more preferably 45% to 75%; the material residence time inside the silo is preferably 3min to 30min, more preferably 5min to 15min; the variable frequency feeder 408 can be installed in... The intelligent flow-stabilizing homogenizing silo 400 has an infeed side and / or an outlet side; an outlet metering device 409 is installed at the outlet 403; a variable frequency feeder 408 and an outlet metering device 409 are used to adjust the flow rate of intermediate powder entering the silo body 401 and / or being output from the silo body 401 to the ultrafine ball mill grinding unit 500; the frequency adjustment range of the variable frequency feeder 408 is preferably 20Hz to 50Hz, more preferably 30Hz to 45Hz; the flow rate fluctuation of the intelligent flow-stabilizing homogenizing silo 400 is preferably controlled within ±8%, more preferably within ±5%.

[0083] When the material level detector 404 detects that the material level in the bin is below 30%, the collaborative control unit 900 reduces the discharge rate of the intelligent flow homogenization bin 400 or reduces the feed rate of the ultrafine ball mill grinding unit 500 to avoid material interruption operation; when the material level in the bin is above 85%, the collaborative control unit 900 increases the discharge frequency or reduces the feed ratio of the channel 311 leading to the intelligent flow homogenization bin to avoid bin fullness and material blockage.

[0084] like Figure 5As shown, the ultrafine ball mill grinding unit 500 includes an ultrafine ball mill 501; the ultrafine ball mill 501 includes a feed end 502, a first grinding chamber 503, a second grinding chamber 504, a third grinding chamber 505, a chamber partition structure 506, grinding balls 507, a primary return material inlet 508, a secondary return material inlet 509, a tertiary return material inlet 510, and a discharge end 511; the feed end 502 is connected to the discharge port 403 of the intelligent flow stabilization and homogenization chamber 400; the first grinding chamber 503, the second grinding chamber 504, and the third grinding chamber 505 are sequentially arranged in the ultrafine ball mill 501 along the material flow direction and are separated from each other by the chamber partition structure 506; the chamber partition structure 506 can be a partition plate, a grate plate, a screen partition plate, or a partition structure with material passage holes, used to control the material to move step by step along the axial direction and form different grinding zones.

[0085] The first grinding chamber 503 is used for coarse grinding and crushing, and its length ratio is preferably 25% to 40% of the total effective grinding length of the ultrafine ball mill 501. The particle size of the grinding balls 507 in the first grinding chamber 503 is preferably 30mm to 60mm, more preferably 40mm to 50mm. The second grinding chamber 504 is used for fine grinding, and its length ratio is preferably 30% to 45% of the total effective grinding length. The particle size of the grinding balls 507 in the second grinding chamber 504 is preferably 15mm to 35mm, more preferably 20mm to 30mm. The third grinding chamber 505 is used for ultrafine grinding, shaping, and dispersion, and its length ratio is preferably 20mm to 30mm. Preferably, the grinding length is 20% to 35% of the total effective grinding length. The particle size of the grinding balls 507 in the third grinding chamber 505 is preferably 5mm to 20mm, more preferably 8mm to 15mm. With the above grinding chamber configuration, the ultrafine ball mill 501 forms a zoned grinding structure along the material flow direction, in which the grinding energy gradually decreases and the particle size of the grinding media gradually decreases. The first grinding chamber 503 is suitable for processing coarse powder with a large particle size or coarse particles in the newly entered grinding material. The second grinding chamber 504 is suitable for processing intermediate coarse powder. The third grinding chamber 505 is suitable for processing return powder with a particle size close to qualified but requiring shaping, dispersion or homogenization treatment.

[0086] The primary return material inlet 508 is connected to the first grinding chamber 503 and is used to receive coarse powder; the secondary return material inlet 509 is connected to the second grinding chamber 504 and is used to receive intermediate coarse powder; the tertiary return material inlet 510 is connected to the third grinding chamber 505 and is used to receive return powder with a particle size close to qualified but still requiring shaping, dispersion or homogenization treatment; the discharge end 511 is connected to the feed end of the deagglomeration and classification unit 600; the mill filling rate of the ultrafine ball mill 501 is preferably 25% to 35%; the moisture content of the feed material is preferably not greater than 1.5%; the temperature of the discharge material is preferably not greater than 110℃; the working current of the ball mill is preferably controlled at 70% to 90% of the rated current; the current fluctuation of the ball mill is preferably not greater than ±8%; the ratio of the amount of returned powder to the amount of finished product is preferably controlled at 0.2 to 1.2; when the ratio of the amount of returned powder to the amount of finished product is greater than or equal to 1.5 and lasts for more than 10 minutes, the coordinating control unit 900 triggers a circulating load abnormality alarm; the feed adjustment cycle is preferably 5s to 30s.

[0087] like Figure 6 As shown, the deagglomeration and classification unit 600 includes a deagglomerator 601, a classification device 602, a high-efficiency classifier 603, a classification airflow regulating device 604, a fine powder outlet 605, and a coarse powder outlet 606. The feed end of the deagglomerator 601 is connected to the discharge end 511 of the ultrafine ball mill fine grinding unit 500, and is used to deagglomerate and disperse the powder exiting the mill. The rotation speed of the deagglomerator 601 is preferably 800 r / min to 3000 r / min, more preferably 1200 r / min to 2200 r / min. The deagglomeration residence time of the powder in the deagglomerator 601 is preferably 0.5 s to 8 s, more preferably 1 s to 5 s. Through deagglomeration treatment, some powder agglomerates formed by electrostatic adsorption, moisture action, or mechanical extrusion can be destroyed, reducing the proportion of pseudo-coarse powder.

[0088] The feed end of the classifying device 602 is connected to the discharge end of the deagglomerator 601, and the discharge end of the classifying device 602 is connected to the feed end of the high-efficiency classifier 603. The classifying device 602 can be a pre-disperser, a cyclone pre-classifier, an airflow dispersion device, or a flow guide structure with pre-classification function, used to improve the dispersion state of the powder before it enters the high-efficiency classifier 603. The high-efficiency classifier 603 is used to separate the deagglomerated powder into qualified fine powder and coarse powder. The classifying airflow regulating device 604 is connected to the high-efficiency classifier 603 and is used to regulate parameters such as the classifying airflow speed, system negative pressure, classifying air volume, or rotor speed. The rotor speed of the high-efficiency classifier 603 is preferably 600 r / min to 250 r / min. The speed is preferably 0 r / min, more preferably 900 r / min to 1800 r / min; the classifying airflow velocity is preferably 8 m / s to 30 m / s, more preferably 12 m / s to 22 m / s; the negative pressure of the classification system is preferably -500 Pa to -3500 Pa, more preferably -1000 Pa to -2500 Pa; the target classification cutting particle size is preferably 10 μm to 30 μm, more preferably 12 μm to 20 μm; the fine powder outlet 605 is located on the fine powder output side of the high-efficiency classifier 603 and is connected to the finished product collection unit 800; the coarse powder outlet 606 is located on the coarse powder output side of the high-efficiency classifier 603 and is connected to the coarse powder separation and reflux unit 700.

[0089] The finished product collection unit 800 includes a dust collector 801, a finished product unloading valve 802, and a finished product silo 803. The inlet end of the dust collector 801 is connected to the fine powder outlet 605, and the outlet end of the dust collector 801 is connected to the finished product silo 803 through the finished product unloading valve 802. The dust collector 801 is used to collect qualified fine powder, and the finished product unloading valve 802 is used to control the entry of qualified fine powder into the finished product silo 803. The target indicators of the qualified fine powder are preferably: D50 is 3μm to 10μm, more preferably 4μm to 6μm; D90 is not greater than 25μm, more preferably not greater than 15μm; specific surface area is 650m² / kg to 1200m² / kg, more preferably 800m² / kg to 1000m² / kg; 45μm sieve residue is not greater than 1.0%, more preferably not greater than 0.5%; and finished product moisture content is not greater than 0.8%, more preferably not greater than 0.5%.

[0090] like Figure 6 and Figure 8As shown, the coarse powder separation and reflux unit 700 includes a coarse powder temporary silo 701, a particle size detector 702, an agglomeration degree detector 703, an impurity content detector 704, a reflux flow rate detector 705, a multi-channel reflux valve 706, a first reflux channel 707, a second reflux channel 708, a third reflux channel 709, and a fourth reflux channel 710. The feed end of the coarse powder temporary silo 701 is connected to the coarse powder outlet 606 of the deagglomeration and classification unit 600, and is used to temporarily store coarse powder from the high-efficiency classifier 603. The particle size detector 702, the agglomeration degree detector 703, the impurity content detector 704, and the reflux flow rate detector 705 are respectively installed on the coarse powder temporary silo 701 and / or the coarse powder conveying channel between the coarse powder temporary silo 701 and the multi-channel reflux valve 706, and are respectively connected to the coordinating control unit 900 via communication or electrical connection.

[0091] Particle size detector 702 is used to detect the D50, D90, or particle size distribution of coarse powder; agglomeration detector 703 is used to determine whether the large apparent particle size of coarse powder is mainly caused by powder agglomeration; impurity content detector 704 is used to detect the content of metal impurities, hard-to-grind particles, or abnormal particles in coarse powder; reflux flow detector 705 is used to detect the reflux flow rate of coarse powder; the feed end of multi-channel reflux valve 706 is connected to the discharge end of coarse powder temporary silo 701; one end of the first reflux channel 707 is connected to the first outlet of multi-channel reflux valve 706, and the other end is connected to the first outlet of ultrafine ball mill 501. A grinding chamber 503 or a primary return inlet 508 is connected; one end of a second return channel 708 is connected to the second outlet of a multi-channel return valve 706, and the other end is connected to the second grinding chamber 504 or a secondary return inlet 509 of an ultrafine ball mill 501; one end of a third return channel 709 is connected to the third outlet of a multi-channel return valve 706, and the other end is connected to the feed side of a deagglomeration and classification unit 600; one end of a fourth return channel 710 is connected to the fourth outlet of a multi-channel return valve 706, and the other end is connected to a vertical mill pretreatment unit 200 or an iron removal screening device 203.

[0092] The agglomeration degree detector 703 is used to characterize the agglomeration state of coarse powder. Its working principle is as follows: by measuring the particle size change of the coarse powder before and after deagglomeration treatment, the degree of agglomeration K of the powder is calculated. The agglomeration degree K is determined according to the following formula: K = (D90 before deagglomeration - D90 after deagglomeration) / (D90 before deagglomeration) × 100%; D90 before deagglomeration is the D90 particle size value of the coarse powder before treatment, and D90 after deagglomeration is the D90 particle size value of the coarse powder after deagglomeration treatment. This detection method can use existing particle size analyzers, such as laser particle size analyzers, sieves, or dynamic image particle size analyzers, combined with short-time deagglomeration operations. Therefore, the agglomeration degree detector does not need to be a separate device, but rather functionally consists of the existing detection device and deagglomeration process. This detector can determine whether there is significant agglomeration in the coarse powder, thereby guiding the selection of the reflux path and milling adjustment. The co-control unit 900 determines the type of coarse powder based on the detection results of the particle size detector 702, agglomeration degree detector 703, impurity content detector 704, and reflux flow detector 705. When the coarse powder D90 is greater than 30 μm and the agglomeration degree K is less than 20%, the coarse powder is identified as true coarse powder, and the multi-channel reflux valve 706 is controlled to allow the true coarse powder to pass through. The powder returns to the first grinding chamber 503 or the primary return inlet 508 via the first reflux channel 707. When the coarse powder D90 is greater than 15μm and less than or equal to 30μm, and the agglomeration degree K is less than 20%, the coarse powder is identified as intermediate coarse powder, and the multi-channel reflux valve 706 is controlled to return the intermediate coarse powder to the second grinding chamber 504 or the secondary return inlet 509 via the second reflux channel 708. When the coarse powder D90 is greater than the target D90 threshold and the agglomeration degree K is greater than or equal to 20%, the coarse powder is identified as pseudo-coarse powder, and the multi-channel reflux valve 706 is controlled to return the pseudo-coarse powder via the third reflux channel 708. Channel 709 returns to the deagglomeration and classification unit 600; when the content of metal impurities in the coarse powder is greater than 0.03wt% or the content of abnormal particles is greater than 0.10wt%, the coarse powder is judged as impurity-containing coarse powder, and the multi-channel reflux valve 706 is controlled to return the impurity-containing coarse powder to the vertical mill pretreatment unit 200 or the iron removal screening device 203 through the fourth reflux channel 710; preferably, when the agglomeration degree K is greater than or equal to 30%, the co-control unit 900 preferentially judges the coarse powder as false coarse powder and returns it to the deagglomeration and classification unit 600 to reduce repeated ball milling caused by misjudgment of agglomeration.

[0093] The target D90 threshold can be preset according to the fineness requirements of the finished product, the graded cutting particle size, or the process control target, for example, set to 15μm, 20μm, or 25μm, or adjusted according to the finished product D90 control target. When the coarse powder meets the judgment conditions of two or more coarse powder types at the same time, the collaborative control unit 900 determines the coarse powder type according to the preset priority. Preferably, the preset priority is, in order, impurity-containing coarse powder, pseudo-coarse powder, true coarse powder, and intermediate coarse powder. That is, when the content of metal impurities or abnormal particles in the coarse powder exceeds the set threshold, it is preferentially judged as impurity-containing coarse powder. When the coarse powder does not exceed the impurity threshold but the agglomeration degree K is greater than or equal to the agglomeration degree set threshold, it is preferentially judged as pseudo-coarse powder. When the coarse powder does not exceed the impurity threshold and the agglomeration degree K is less than the set threshold, it is then judged as true coarse powder or intermediate coarse powder according to the coarse powder D90. In this way, the backflow path conflict can be avoided when the same batch of coarse powder meets multiple judgment conditions at the same time.

[0094] like Figure 1 , Figure 2 and Figure 8 As shown, the collaborative control unit 900 includes a data acquisition module, a quality detection and analysis module, a process optimization module, a multi-objective decision-making module, an equipment collaborative control module, and an execution and feedback module. The collaborative control unit 900 can be implemented using a PLC control system, a DCS control system, an industrial computer control system, or a combination of the above systems. The data acquisition module is communicatively or electrically connected to the intermediate material online detection and diversion unit 300, the intelligent stable flow homogenization bin 400, the ultrafine ball mill fine grinding unit 500, the deagglomeration and classification unit 600, the coarse powder separation and reflux unit 700, and the finished product collection unit 800, respectively, for collecting intermediate powder detection parameters, homogenization bin material level and discharge rate, ball mill current and grinding noise, classifier operating parameters, finished product fineness, coarse powder detection parameters, and coarse powder reflux rate. The quality detection and analysis module is connected to the data acquisition and diversion unit 300, the intelligent stable flow homogenization bin 400, the ultrafine ball mill fine grinding unit 500, the deagglomeration and classification unit 600, the coarse powder separation and reflux unit 700, and the finished product collection unit 800. The data acquisition module is connected to analyze the state of intermediate powder, the state of powder exiting the mill, the fineness of the finished product, and the type of coarse powder. The process optimization module is connected to the quality detection and analysis module to generate optimized schemes for intermediate powder diversion, mill feeding, ball mill reflux, classification adjustment, and coarse powder reflux. The multi-objective decision-making module is connected to the process optimization module to determine control commands based on finished product fineness, system output, equipment load, reflux flow rate, and operational stability. The equipment collaborative control module is connected to the multi-objective decision-making module and outputs control signals to the multi-channel diversion valve 308, the variable frequency feeder 408, the discharge metering device 409, the classification airflow adjustment device 604, and the multi-channel reflux valve 706, respectively. The execution and feedback module is connected to the equipment collaborative control module to collect feedback data after control execution and return it to the data acquisition module.

[0095] The collaborative control unit 900 can be implemented using rule-based control based on preset thresholds, or using PID control, model predictive control, expert system control, or adaptive control based on historical operating data. When using rule-based control, the collaborative control unit 900 compares at least some of the detection parameters, including intermediate powder D90, moisture, temperature, metal impurity content, flow rate, material level and discharge rate of the intelligent flow stabilization and homogenization silo 400, current and grinding noise of the ultrafine ball mill 501, classifier speed, classifying airflow parameters, coarse powder D90, agglomeration degree K, coarse powder impurity content, and coarse powder return flow, with preset thresholds. Based on the comparison results, it outputs control commands for the multi-channel diversion valve 308, variable frequency feeder 408, discharge metering device 409, classifying airflow regulating device 604, and multi-channel return valve 706. The above control process can be implemented by PLC, DCS, or industrial computer programs without relying on a specific algorithm model.

[0096] The real-time parameters collected by the collaborative control unit 900 include: raw material feed rate, raw material silo level, weighing feed signal, vertical mill current, mill internal pressure difference, outlet temperature, hot air temperature, vertical mill vibration, intermediate powder D50, intermediate powder D90, intermediate powder moisture content, intermediate powder temperature, intermediate powder flow rate, intermediate powder metal impurity content, intelligent flow homogenization silo level, intelligent flow homogenization silo weight, intelligent flow homogenization silo discharge rate, fluidizing air pressure, ultrafine ball mill current, mill noise, bearing temperature, feed rate, discharge temperature, classifier speed, classifying airflow velocity, system negative pressure, fine powder quantity, coarse powder quantity, coarse powder D90, coarse powder agglomeration degree K, and coarse powder... At least five parameters are selected from the following: impurity content, coarse powder reflux flow rate, finished product D50, finished product D90, finished product specific surface area, finished product moisture content, and 45μm sieve residue. The preferred acquisition period for raw material conveying parameters is 1s to 5s; for vertical mill parameters, it is 1s to 10s; for intermediate material parameters, it is 5s to 60s; for homogenization bin parameters, it is 1s to 10s; for ball mill parameters, it is 1s to 10s; for classification parameters, it is 1s to 10s; for coarse powder parameters, it is 10s to 60s; and for finished product parameters, it is 5min to 60min.

[0097] When the intermediate powder D90 is consistently greater than 180μm, the co-control unit 900 increases the opening ratio of the return vertical mill channel 310 and reduces the feed ratio into the intelligent flow stabilization and homogenization bin 400; when the intermediate powder moisture content is greater than 1.5%, the co-control unit 900 increases the hot air temperature or hot air volume of the hot air system 202 and returns this portion of the intermediate powder to the vertical mill pretreatment unit 200; when the intermediate powder D90 is not greater than 45μm and the specific surface area is not less than 600m² / kg, the co-control unit 900 adds a bypass grading channel 31. The opening ratio of 2; when the discharge fluctuation of the intelligent flow stabilization bin 400 exceeds ±8%, the collaborative control unit 900 adjusts the fluidizing air pressure and the frequency of the variable frequency feeder 408 in the bin; when the current of the ultrafine ball mill 501 exceeds 90% of the rated current and the coarse powder return flow increases, the collaborative control unit 900 reduces the feed rate into the mill and adjusts the coarse powder return path; when the coarse powder does not exceed the impurity threshold and the agglomeration degree K is greater than or equal to 20%, the collaborative control unit 900 prioritizes opening the third return channel 709, so that the pseudo coarse powder returns to the deagglomeration and classification unit 600.

[0098] The present invention also provides a method for synergistically preparing ultrafine powder, which is implemented using the above-mentioned dual grinding system and includes the following steps:

[0099] S1, the raw material to be ground is conveyed to the vertical mill pretreatment unit 200 through the raw material conveying unit 100;

[0100] S2, the raw material to be ground is pre-ground, dried and impurity removed by the vertical mill pre-treatment unit 200 to obtain intermediate powder;

[0101] S3, the intermediate powder is detected by the intermediate material online detection and diversion unit 300, which detects at least two parameters among particle size, moisture, specific surface area, temperature, flow rate and impurities;

[0102] S4, the controller 309 determines the intermediate powder as abnormal intermediate material, normal intermediate material, or intermediate material with a fineness close to that of the finished product based on the intermediate powder detection results;

[0103] S5, when intermediate powder is determined to be abnormal intermediate material, the intermediate powder is returned to the vertical mill pretreatment unit 200 via the return vertical mill channel 310 through the multi-channel diversion valve 308.

[0104] S6, when the intermediate powder is determined to be normal intermediate material, the intermediate powder is directed through the multi-channel diversion valve 308 to enter the intelligent flow homogenization silo 400 through the channel 311 leading to the intelligent flow homogenization silo, and the intermediate powder is buffered, homogenized, prevented from segregation, fluidized and metered through the intelligent flow homogenization silo 400.

[0105] S7, when the intermediate powder is determined to be an intermediate material with a fineness close to that of the finished product, the intermediate powder is allowed to enter the bypass classifier 300B through the bypass classification channel 312 via the multi-channel diversion valve 308.

[0106] S8, the intermediate powder processed by the intelligent flow homogenization chamber 400 is transported to the ultrafine ball mill fine grinding unit 500, and finely ground in the first grinding chamber 503, the second grinding chamber 504 and the third grinding chamber 505 of the ultrafine ball mill 501 to obtain the milled powder.

[0107] S9, the powder exiting the mill is conveyed to the deagglomeration and classification unit 600, and is deagglomerated, dispersed and classified in sequence through the deagglomerator 601, the classification device 602 and the high-efficiency classifier 603 to obtain qualified fine powder and coarse powder;

[0108] S10, the qualified fine powder is conveyed to the finished product collection unit 800 through the fine powder outlet 605, and collected through the dust collector 801, the finished product unloading valve 802 and the finished product bin 803;

[0109] S11, the coarse powder is conveyed to the coarse powder separation and reflux unit 700 through the coarse powder outlet 606, and the state of the coarse powder is detected by at least two of the particle size detector 702, agglomeration detector 703, impurity content detector 704 and reflux flow detector 705.

[0110] S12, the co-control unit 900 determines the type of coarse powder based on its state and controls the multi-channel reflux valve 706 to select the coarse powder reflux path. Among them, true coarse powder returns to the first grinding chamber 503 or the primary return inlet 508 through the first reflux channel 707, intermediate coarse powder returns to the second grinding chamber 504 or the secondary return inlet 509 through the second reflux channel 708, false coarse powder returns to the deagglomeration and classification unit 600 through the third reflux channel 709, and impurity-containing coarse powder returns to the vertical mill pretreatment unit 200 or the iron removal screening device 203 through the fourth reflux channel 710.

[0111] S13, the collaborative control unit 900 adjusts the working status of the multi-channel diversion valve 308, the frequency conversion feeder 408, the discharge metering device 409, the classification airflow regulating device 604, and the multi-channel reflux valve 706 based on the intermediate powder detection results, the material level and discharge rate of the intelligent flow stabilization homogenization silo 400, the operating status of the ultrafine ball mill 501, the classification status of the deagglomeration and classification unit 600, and the fineness and coarse powder detection results of the finished product.

[0112] Figure 8T1 to T7 in the above method refer to the refined sub-steps of the powder deagglomeration and classification, coarse powder detection, coarse powder type determination, and fractional reflux process. They are not replacements for the complete method step numbers S1 to S13. Specifically, T1 corresponds to the ultrafine ball mill discharge process, T2 and T3 correspond to deagglomeration and classification in step S9, T4 corresponds to the determination of qualified fine powder and coarse powder in step S9, T5 corresponds to step S10, T6 corresponds to step S11, and T7 corresponds to step S12. Figure 8 The collaborative control unit 900 in the middle corresponds to step S13.

[0113] In one specific operating mode, the raw material to be ground is a composite material of slag and steel slag, with a particle size not exceeding 25 mm and a moisture content of 3% to 8%. A weighing feeder 104 feeds the raw material into the vertical mill 201 according to a set feed rate. A hot air system 202 provides hot air to the vertical mill 201, ensuring that the moisture content of the intermediate powder at the mill outlet is not greater than 1.5%. An iron removal screening device 203 removes metallic impurities from the raw material and intermediate powder. After the intermediate powder enters the sampling and testing chamber 301, a particle size detector 3... 02 detects D90, moisture detector 303 detects moisture, metal impurity detector 306 detects metal impurity content, and flow detector 307 detects intermediate powder flow rate; if the intermediate powder is detected to have D90 of 100μm, moisture of 0.9%, temperature of 75℃, metal impurity content of 0.015wt%, and flow fluctuation of ±5%, the judgment controller 309 determines it as normal intermediate material and controls the multi-channel diversion valve 308 to allow the intermediate powder to enter the intelligent flow stabilization and homogenization chamber 400.

[0114] The intelligent flow-stabilizing homogenization bin 400 controls the material level within the bin at 45%–75%, the fluidizing air pressure at 5 kPa–8 kPa, and the discharge flow rate fluctuation within ±5%. The intermediate powder after flow-stabilizing homogenization enters the ultrafine ball mill 501, where it undergoes zoned grinding sequentially through the first grinding chamber 503, the second grinding chamber 504, and the third grinding chamber 505. The ball mill's operating current is controlled at 70%–90% of its rated current, and the temperature of the discharged material does not exceed 110℃. The discharged powder then enters the dewatering chamber. The agglomerator 601 deagglomerates and disperses the particles, which are then classified by the classifier 602 and the high-efficiency classifier 603. Qualified fine powder enters the dust collector 801 through the fine powder outlet 605, and then enters the finished product silo 803 through the finished product discharge valve 802. Coarse powder enters the coarse powder temporary silo 701 through the coarse powder outlet 606, where it is detected by the particle size detector 702, agglomeration degree detector 703, impurity content detector 704, and reflux flow detector 705. If the coarse powder has a D90 of 35μm and an agglomeration degree K of 1... If the particle size is 0%, the co-control unit 900 determines it as true coarse powder and controls the multi-channel reflux valve 706 to return it to the first grinding chamber 503 via the first reflux channel 707; if the coarse powder D90 is 22μm and the agglomeration degree K is 12%, it is determined as intermediate coarse powder and returns it to the second grinding chamber 504 via the second reflux channel 708; if the coarse powder D90 is greater than the target D90 threshold and the agglomeration degree K is 25%, it is determined as false coarse powder and returns it to the deagglomeration and classification unit via the third reflux channel 709. 600; If the metal impurity content in the coarse powder is greater than 0.03wt%, it is determined to be impurity-containing coarse powder and returned to the vertical mill pretreatment unit 200 or iron removal screening device 203 through the fourth reflux channel 710; Through the above operation mode, the finished ultrafine powder can be controlled to have D50 of 3μm~10μm, D90 not greater than 25μm, specific surface area of ​​650m² / kg~1200m² / kg, 45μm sieve residue not greater than 1.0%, and finished product moisture not greater than 0.8%.

[0115] In other alternative implementations, the ultrafine ball mill 501 can be configured as a two-chamber, three-chamber, or more-plus-chamber partitioned grinding structure, as long as it can form grinding zones with different grinding energies or different grinding media particle sizes, and can receive partitioned reflux of different types of coarse powder, all of which are embodiments of the present invention; the intermediate material online detection and diversion unit 300 may not be equipped with all detectors at the same time, but may select at least two of the particle size detector 302, moisture detector 303, specific surface area estimation unit 304, temperature detector 305, metal impurity detector 306, and flow detector 307 for combined detection according to the raw material type and control requirements; the agglomeration degree K in the coarse powder separation and reflux unit 700 can be determined by... The agglomeration degree can be obtained directly through online detection, or through bypass sampling, short-term deagglomeration, particle size retesting, and model calculation. For production lines that do not have the conditions for online detection of agglomeration degree, an equivalent judgment model can be established using coarse powder D90, reflux flow rate changes, finished product D90 changes, deagglomerator load, and ball mill current changes to identify false coarse powder. The collaborative control unit 900 can adopt rule control, PID control, model predictive control, expert system control, or adaptive control based on historical operating data. As long as the diversion path, mill feed, classification parameters, and reflux path can be collaboratively adjusted according to the intermediate powder state, ball mill operating state, classification state, finished product fineness, and coarse powder state, the purpose of this invention can be achieved.

[0116] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A system for synergistically preparing ultrafine powder by double-pulverizing, comprising a raw material conveying unit (100), a vertical mill pretreatment unit (200), an intermediate material online detection and shunting unit (300), an intelligent flow stabilizing and homogenizing bin (400), an ultrafine ball mill fine grinding unit (500), a depolymerization and classification unit (600), a coarse powder quality-based reflux unit (700), a finished product collecting unit (800), and a synergistic control unit (900), characterized in that: The raw material conveying unit (100), the vertical mill pretreatment unit (200), the intermediate material online detection and diversion unit (300), the intelligent flow stabilization and homogenization bin (400), the ultrafine ball mill fine grinding unit (500), the deagglomeration and classification unit (600), and the finished product collection unit (800) are connected in sequence along the material conveying direction. The discharge end of the raw material conveying unit (100) is connected to the feed end of the vertical mill pretreatment unit (200) to convey the raw material to be ground to the vertical mill pretreatment unit (200). The vertical mill pretreatment unit (200) is used to pre-grind, dry, and remove impurities from the raw material to be ground, and output intermediate powder. The intermediate material online detection and diversion unit (300) is set on the discharge side of the vertical mill pretreatment unit (200) to detect at least two parameters of the intermediate powder, including particle size, moisture, specific surface area, temperature, metal impurity content, and flow rate, and classifies the intermediate powder into abnormal intermediate material, normal intermediate material, and intermediate material with near-finished product fineness according to the detection results. The intermediate material online detection and diversion unit (300) is connected to the vertical mill pretreatment unit (200), the intelligent flow homogenization chamber (400), and the bypass classifier (300B) through the return vertical mill channel (310), the channel leading to the intelligent flow homogenization chamber (311), and the bypass classification channel (312), respectively. This allows abnormal intermediate materials to return to the vertical mill pretreatment unit (200), normal intermediate materials to enter the intelligent flow homogenization chamber (400), and intermediate materials with a fineness close to that of the finished product to enter the bypass classifier (300B). The discharge end of the intelligent flow homogenization bin (400) is connected to the feed end of the ultrafine ball mill grinding unit (500) for buffering, homogenizing, preventing segregation, fluidizing and metering the intermediate powder before it enters the ultrafine ball mill grinding unit (500). The ultrafine ball mill grinding unit (500) includes an ultrafine ball mill (501). The ultrafine ball mill (501) has a first grinding chamber (503), a second grinding chamber (504) and a third grinding chamber (505) arranged sequentially along the material flow direction. The first grinding chamber (503), the second grinding chamber (504) and the third grinding chamber (505) are separated from each other by a cavity partition structure (506). The particle size of the grinding balls (507) in the first grinding chamber (503), the second grinding chamber (504) and the third grinding chamber (505) decreases step by step along the material flow direction. The ultrafine ball mill (501) is equipped with a primary return inlet (508), a secondary return inlet (509) and a tertiary return inlet (510). The primary return inlet (508) is connected to the first grinding chamber (503), the secondary return inlet (509) is connected to the second grinding chamber (504), and the tertiary return inlet (510) is connected to the third grinding chamber (505). The deagglomeration and classification unit (600) is located on the discharge side of the ultrafine ball mill fine grinding unit (500) and is used to deagglomerate, disperse and classify the powder discharged from the mill. Qualified fine powder is output through the fine powder outlet (605) and coarse powder is output through the coarse powder outlet (606). The fine powder outlet (605) is connected to the finished product collection unit (800), and the coarse powder outlet (606) is connected to the coarse powder separation and reflux unit (700). The coarse powder separation and reflux unit (700) is used to detect at least two parameters among the particle size, agglomeration degree, impurity content, and reflux flow rate of the coarse powder, and to classify the coarse powder into true coarse powder, intermediate coarse powder, pseudo coarse powder, and impurity-containing coarse powder according to the detection results; the coarse powder separation and reflux unit (700) is connected to the first grinding chamber (503) or the primary return material inlet (508) through the first reflux channel (707), and to the second grinding chamber (504) or the secondary return material inlet (509) through the second reflux channel (708), and to the third reflux flow rate. The channel (709) is connected to the deagglomeration and classification unit (600), and is connected to the vertical mill pretreatment unit (200) or the iron removal screening device (203) through the fourth return channel (710), so that the true coarse powder is returned to the first grinding chamber (503) or the primary return inlet (508), the intermediate coarse powder is returned to the second grinding chamber (504) or the secondary return inlet (509), the false coarse powder is returned to the deagglomeration and classification unit (600), and the impurity-containing coarse powder is returned to the vertical mill pretreatment unit (200) or the iron removal screening device (203); The collaborative control unit (900) is connected or electrically connected to the intermediate material online detection and diversion unit (300), the intelligent steady flow homogenization bin (400), the ultrafine ball mill fine grinding unit (500), the deagglomeration and classification unit (600), and the coarse powder separation and return unit (700), respectively. It is used to coordinately adjust the intermediate material diversion path, the feed rate into the mill, the classification parameters, and the coarse powder return path according to the intermediate material detection results, the material level and discharge rate of the intelligent steady flow homogenization bin (400), the operating status of the ultrafine ball mill (501), the classification status of the deagglomeration and classification unit (600), the fineness of the finished product, and the coarse powder detection results.

2. A system for simultaneous production of ultrafine powder by a dual-pulverizer according to claim 1, wherein: The raw material conveying unit (100) includes a feeding bin (101), a raw material elevator (102), a raw material bin (103), and a weighing feeder (104) connected in sequence; the discharge end of the feeding bin (101) is connected to the feed end of the raw material elevator (102), the discharge end of the raw material elevator (102) is connected to the feed end of the raw material bin (103), the discharge end of the raw material bin (103) is connected to the feed end of the weighing feeder (104), and the discharge end of the weighing feeder (104) is connected to the feed end of the vertical mill pretreatment unit (200); The vertical mill pretreatment unit (200) includes a vertical mill (201), a hot air system (202), an iron removal screening device (203), and a vertical mill dust collector (206). The hot air system (202) is connected to the vertical mill (201) and is used to provide drying hot air to the vertical mill (201). The iron removal screening device (203) is set on the discharge side of the vertical mill (201) or in the material conveying channel and is used to remove metal impurities or abnormal particles in the intermediate powder. The vertical mill dust collector (206) is connected to the dust-laden airflow outlet of the vertical mill (201) and is used to collect the dust generated during the vertical mill pretreatment process.

3. The system for producing ultrafine powder in conjunction with a dual mill according to claim 1, characterized in that: The intermediate material online detection and diversion unit (300) includes a sampling detection chamber (301), a particle size detector (302), a moisture detector (303), a specific surface area estimation unit (304), a temperature detector (305), a metal impurity detector (306), a flow rate detector (307), a multi-channel diversion valve (308), and a judgment controller (309). The feed end of the sampling detection chamber (301) is connected to the discharge end of the vertical mill pretreatment unit (200), and the discharge end of the sampling detection chamber (301) is connected to the feed end of the multi-channel diversion valve (308). The particle size detector (302), moisture detector (303), specific surface area estimation unit (304), temperature detector (305), metal impurity detector (306), flow rate detector (307), multi-channel diversion valve (308), and judgment controller (309) are all connected. The calculation unit (304), temperature detector (305), metal impurity detector (306), and flow detector (307) are respectively set to the sampling detection chamber (301) and are respectively connected to the judgment controller (309) for communication or electrical connection; the judgment controller (309) is connected to the multi-channel diversion valve (308) for communication or electrical connection, and is used to control the diversion state of the multi-channel diversion valve (308) according to at least two detection results of particle size detector (302), moisture detector (303), specific surface area estimation unit (304), temperature detector (305), metal impurity detector (306), and flow detector (307); The multi-channel diverter valve (308) includes a return channel (310) to the vertical mill, a channel (311) to the intelligent flow homogenization chamber, and a bypass grading channel (312); the outlet of the return channel (310) is connected to the feed side or the circulating feed side of the vertical mill pretreatment unit (200); the outlet of the channel (311) to the intelligent flow homogenization chamber is connected to the feed inlet (402) of the intelligent flow homogenization chamber (400); the outlet of the bypass grading channel (312) is connected to the feed end of the bypass classifier (300B); When the controller (309) determines that the intermediate powder is abnormal, it controls the multi-channel diversion valve (308) to return the intermediate powder to the vertical mill pretreatment unit (200) via the return vertical mill channel (310). When the controller (309) determines that the intermediate powder is normal intermediate material, it controls the multi-channel diversion valve (308) to allow the intermediate powder to enter the intelligent flow homogenization chamber (400) through the channel (311) leading to the intelligent flow homogenization chamber. When the controller (309) determines that the intermediate powder is close to the fineness of the finished product, it controls the multi-channel diversion valve (308) to allow the intermediate powder to enter the bypass classifier (300B) through the bypass classification channel (312).

4. The system for producing ultrafine powder in conjunction with a dual mill according to claim 1, characterized in that: The intelligent flow equalization bin (400) includes a bin body (401), a feed inlet (402), a discharge outlet (403), a material level detector (404), a weighing detector (405), an in-bin fluidization device (406), an anti-segregation flow guiding structure (407), a frequency conversion feeding device (408), and a discharge metering device (409); the feed inlet (402) is located at the top of the bin body (401) and is connected to the channel (311) of the intermediate material online detection and diversion unit (300) leading to the intelligent flow equalization bin; The discharge port (403) is located at the lower part of the silo body (401) and connected to the feed end of the ultrafine ball mill grinding unit (500); the anti-segregation flow guiding structure (407) is located inside the silo body (401) and between the feed port (402) and the discharge port (403); the fluidization device (406) is located at the lower or lower middle part of the silo body (401) to improve the flowability of the powder in the silo; the material level detector (404) is located on the silo body (401) to detect the material level in the silo; weighing The detector (405) is connected to the silo (401) and is used to detect the weight or weight change of the material in the silo; the variable frequency feeder (408) is set on the feed side and / or discharge side of the intelligent flow stabilization silo (400), and the discharge metering device (409) is set at the discharge port (403). The variable frequency feeder (408) and the discharge metering device (409) are used to adjust the flow rate of intermediate powder entering the silo (401) and / or output from the silo (401) to the ultrafine ball mill fine grinding unit (500).

5. A system for simultaneous production of ultrafine powder by a dual mill according to claim 1, characterized in that: The ultrafine ball mill refining unit (500) includes an ultrafine ball mill (501), which includes a feed end (502), a first grinding chamber (503), a second grinding chamber (504), a third grinding chamber (505), a chamber partition structure (506), grinding balls (507), a primary return material inlet (508), a secondary return material inlet (509), a tertiary return material inlet (510), and a discharge end (511). The feed end (502) is connected to the discharge port (403) of the intelligent flow stabilization and homogenization chamber (400). The first grinding chamber (503), the second grinding chamber (504), and the third grinding chamber (505) are arranged sequentially along the material flow direction in the ultrafine ball mill. Inside the fine ball mill (501), the grinding balls (507) are separated from each other by a cavity partition structure (506); the grinding balls (507) in the first grinding chamber (503) have a larger particle size than the grinding balls (507) in the second grinding chamber (504), and the grinding balls (507) in the second grinding chamber (504) have a larger particle size than the grinding balls (507) in the third grinding chamber (505); the primary return inlet (508) is connected to the first grinding chamber (503), the secondary return inlet (509) is connected to the second grinding chamber (504), and the tertiary return inlet (510) is connected to the third grinding chamber (505); the discharge end (511) is connected to the feed end of the deagglomeration and classification unit (600); The length ratio of the first grinding chamber (503) is 25% to 40% of the total effective grinding length of the ultrafine ball mill (501), and the particle size of the grinding balls (507) in the first grinding chamber (503) is 30mm to 60mm. The length ratio of the second grinding chamber (504) is 30% to 45% of the total effective grinding length of the ultrafine ball mill (501), and the particle size of the grinding balls (507) in the second grinding chamber (504) is 15mm to 35mm. The length ratio of the third grinding chamber (505) is 20% to 35% of the total effective grinding length of the ultrafine ball mill (501), and the particle size of the grinding balls (507) in the third grinding chamber (505) is 5mm to 20mm. The primary return inlet (508) is used to receive coarse powder, the secondary return inlet (509) is used to receive intermediate coarse powder, and the tertiary return inlet (510) is used to receive return powder with a particle size close to qualified but requiring shaping, dispersion or homogenization treatment.

6. A system for simultaneous production of ultrafine powder by a dual mill according to claim 1, characterized in that: The deagglomeration and classification unit (600) includes a deagglomerator (601), a classification device (602), a high-efficiency classifier (603), a classification airflow regulating device (604), a fine powder outlet (605), and a coarse powder outlet (606); the feed end of the deagglomerator (601) is connected to the discharge end of the ultrafine ball mill grinding unit (500) for deagglomerating and dispersing the powder discharged from the mill; the feed end of the classification device (602) is connected to the discharge end of the deagglomerator (601), and the classification device (602)... The discharge end is connected to the feed end of the high-efficiency classifier (603); the classifying airflow regulating device (604) is connected to the high-efficiency classifier (603) and is used to regulate the classifying airflow parameters of the high-efficiency classifier (603); the fine powder outlet (605) is set on the fine powder output side of the high-efficiency classifier (603) and is connected to the finished product collection unit (800); the coarse powder outlet (606) is set on the coarse powder output side of the high-efficiency classifier (603) and is connected to the coarse powder separation and reflux unit (700); The finished product collection unit (800) includes a dust collector (801), a finished product discharge valve (802), and a finished product silo (803); the feed end of the dust collector (801) is connected to the fine powder outlet (605) of the deagglomeration and classification unit (600); the discharge end of the dust collector (801) is connected to the finished product silo (803) through the finished product discharge valve (802); the dust collector (801) is used to collect qualified fine powder, and the finished product discharge valve (802) is used to control the qualified fine powder to enter the finished product silo (803).

7. A system for simultaneous production of ultrafine powder by a dual mill according to claim 1, characterized in that: The coarse powder separation and reflux unit (700) includes a coarse powder temporary silo (701), a particle size detector (702), an agglomeration degree detector (703), an impurity content detector (704), a reflux flow detector (705), a multi-channel reflux valve (706), a first reflux channel (707), a second reflux channel (708), a third reflux channel (709), and a fourth reflux channel (710); the feed end of the coarse powder temporary silo (701) is connected to the coarse powder outlet (606) of the deagglomeration and classification unit (600); the particle size detector (702), the agglomeration degree detector (703), the impurity content detector (704), and the reflux flow detector (705) are respectively installed on the coarse powder conveying channel between the coarse powder temporary silo (701) and / or the coarse powder conveying channel between the coarse powder temporary silo (701) and the multi-channel reflux valve (706), and are respectively connected to the coordinating control unit (900) via communication or electrical connection; the multi-channel The feed end of the reflux valve (706) is connected to the discharge end of the coarse powder temporary silo (701); one end of the first reflux channel (707) is connected to the first outlet of the multi-channel reflux valve (706), and the other end is connected to the first grinding chamber (503) or the primary return inlet (508) of the ultrafine ball mill (501); one end of the second reflux channel (708) is connected to the second outlet of the multi-channel reflux valve (706), and the other end is connected to the second grinding chamber (504) or the secondary return inlet (509) of the ultrafine ball mill (501); one end of the third reflux channel (709) is connected to the third outlet of the multi-channel reflux valve (706), and the other end is connected to the feed side of the deagglomeration and classification unit (600); one end of the fourth reflux channel (710) is connected to the fourth outlet of the multi-channel reflux valve (706), and the other end is connected to the vertical mill pretreatment unit (200) or the iron removal screening device (203).

8. A system for simultaneous production of ultrafine powder by a dual mill according to claim 1, characterized in that: The co-control unit (900) is configured to determine the type of coarse powder based on the detection results of the particle size detector (702), agglomeration detector (703), impurity content detector (704), and reflux flow detector (705), and control the outlet state of the multi-channel reflux valve (706); when the coarse powder D90 is greater than 30 μm and the agglomeration degree K is less than 20%, the co-control unit (900) determines the coarse powder as true coarse powder and controls the multi-channel reflux valve (706) to return the true coarse powder to the first grinding chamber (503) or the primary return inlet (508) through the first reflux channel (707); when the coarse powder D90 is greater than 15 μm and less than or equal to 30 μm, and the agglomeration degree K is less than 20%, the co-control unit (900) determines the coarse powder as intermediate coarse powder and controls the multi-channel reflux valve (706) to return the intermediate ...). The coarse powder is returned to the second grinding chamber (504) or the secondary return inlet (509) via the second reflux channel (708); when the coarse powder D90 is greater than the target D90 threshold and the agglomeration degree K is greater than or equal to 20%, the co-control unit (900) determines the coarse powder as pseudo coarse powder and controls the multi-channel reflux valve (706) to return the pseudo coarse powder to the deagglomeration and classification unit (600) via the third reflux channel (709); when the metal impurity content in the coarse powder is greater than 0.03wt% or the abnormal particle content is greater than 0.10wt%, the co-control unit (900) determines the coarse powder as impurity-containing coarse powder and controls the multi-channel reflux valve (706) to return the impurity-containing coarse powder to the vertical mill pretreatment unit (200) or the iron removal screening device (203) via the fourth reflux channel (710); wherein, the agglomeration degree K is determined according to the following formula: K = (before D90 disintegration - after D90 disintegration) / before D90 disintegration × 100%.

9. A system for simultaneous production of ultrafine powder by a dual mill according to claim 1, characterized in that: The collaborative control unit (900) includes a data acquisition module, a quality detection and analysis module, a process optimization module, a multi-objective decision-making module, an equipment collaborative control module, and an execution and feedback module. The data acquisition module is connected or electrically connected to the intermediate material online detection and diversion unit (300), the intelligent stable flow homogenization bin (400), the ultrafine ball mill fine grinding unit (500), the deagglomeration and classification unit (600), the coarse powder classification and reflux unit (700), and the finished product collection unit (800), respectively, and is used to collect intermediate powder detection parameters, homogenization bin material level and discharge rate, ball mill current and grinding sound, classifier operating parameters, finished product fineness, coarse powder detection parameters, and coarse powder reflux rate. The quality inspection and analysis module is connected to the data acquisition module to analyze the state of intermediate powder, the state of powder exiting the mill, the fineness of the finished product, and the type of coarse powder. The process optimization module is connected to the quality inspection and analysis module to generate optimized schemes for intermediate powder diversion, mill feeding, ball mill reflux, classification adjustment, and coarse powder reflux. The multi-objective decision-making module is connected to the process optimization module and is used to determine control commands based on finished product fineness, system output, equipment load, reflux flow rate and operational stability. The equipment collaborative control module is connected to the multi-objective decision-making module and outputs control signals to the multi-channel diversion valve (308), the frequency conversion feeder (408), the discharge metering device (409), the graded airflow regulating device (604) and the multi-channel reflux valve (706), respectively. The execution and feedback module is connected to the equipment collaborative control module and is used to collect feedback data after control execution and return it to the data acquisition module.

10. A method of dual mill co-production of ultrafine powder, characterized by, The system for preparing ultrafine powder using dual grinding as described in any one of claims 1 to 9 Includes the following steps: S1, the raw material to be ground is conveyed to the vertical mill pretreatment unit (200) through the raw material conveying unit (100). S2, the raw material to be ground is pre-ground, dried and impurity removed by the vertical mill pre-treatment unit (200) to obtain intermediate powder; S3, the intermediate powder is detected by the intermediate material online detection and diversion unit (300) for at least two parameters of particle size, moisture, specific surface area, temperature, flow rate and impurities; S4, the controller (309) determines the intermediate powder as abnormal intermediate powder, normal intermediate powder or intermediate powder with fineness close to that of finished product based on the detection results of the intermediate powder. S5, when the intermediate powder is determined to be abnormal intermediate material, the intermediate powder is returned to the vertical mill pretreatment unit (200) through the return vertical mill channel (310) via the multi-channel diversion valve (308). S6, when the intermediate powder is determined to be normal intermediate material, the intermediate powder is allowed to enter the intelligent flow homogenization silo (400) through the channel (311) leading to the intelligent flow homogenization silo via the multi-channel diversion valve (308), and the intermediate powder is buffered, homogenized, prevented from segregation, fluidized and metered through the intelligent flow homogenization silo (400); S7, when the intermediate powder is determined to be an intermediate material with a fineness close to that of the finished product, the intermediate powder is allowed to enter the bypass classifier (300B) through the bypass classification channel (312) via the multi-channel diversion valve (308). S8, the intermediate powder processed by the intelligent flow stabilization and homogenization bin (400) is transported to the ultrafine ball mill fine grinding unit (500), and finely ground in the first grinding chamber (503), the second grinding chamber (504) and the third grinding chamber (505) of the ultrafine ball mill (501) to obtain the milled powder; S9, the powder exiting the mill is conveyed to the deagglomeration and classification unit (600), and is deagglomerated, dispersed and classified in sequence through the deagglomerator (601), the classification device (602) and the high-efficiency classifier (603) to obtain qualified fine powder and coarse powder; S10, qualified fine powder is conveyed to the finished product collection unit (800) through the fine powder outlet (605), and collected through the dust collector (801), the finished product unloading valve (802) and the finished product bin (803); S11, the coarse powder is conveyed through the coarse powder outlet (606) to the coarse powder separation and reflux unit (700), and the state of the coarse powder is detected by at least two of the particle size detector (702), agglomeration detector (703), impurity content detector (704) and reflux flow detector (705); S12, the co-control unit (900) determines the type of coarse powder based on its state and controls the multi-channel reflux valve (706) to select the coarse powder reflux path. The true coarse powder returns to the first grinding chamber (503) or the primary return inlet (508) through the first reflux channel (707), the intermediate coarse powder returns to the second grinding chamber (504) or the secondary return inlet (509) through the second reflux channel (708), the pseudo coarse powder returns to the deagglomeration and classification unit (600) through the third reflux channel (709), and the impurity-containing coarse powder returns to the vertical mill pretreatment unit (200) or the iron removal screening device (203) through the fourth reflux channel (710). S13, the collaborative control unit (900) adjusts the working status of the multi-channel diversion valve (308), the frequency conversion feeder (408), the discharge metering device (409), the grading airflow regulating device (604), and the multi-channel reflux valve (706) based on the intermediate powder detection results, the material level and discharge rate of the intelligent flow homogenization silo (400), the operating status of the ultrafine ball mill (501), the grading status of the deagglomeration and grading unit (600), the fineness of the finished product, and the coarse powder detection results.

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