A mine low-energy consumption sizing screen and design method

Abstract

The application discloses a kind of mine low-energy consumption grading machine and design method, belong to mineral dispersion sorting technical field, including outer cavity and to upper to lower sequentially coaxially arranged dispersion unit, first low-resistance air separation unit and second air separation unit;The upper end of outer cavity is provided with feed pipe, and the dispersion unit is communicated directly below feed pipe;Dispersion unit and first low-resistance air separation unit are arranged in outer cavity;Second air separation unit is communicated with the bottom end of outer cavity;Finished product fine powder outlet is equipped in the lower part of second air separation unit;Dispersion unit fully dissociates and disperses cake-shaped material into single particle form;First low-resistance air separation unit carries out pre-sorting to single particle form material, and separates out coarse particle and fine particle;Second air separation unit is used for fine classification to fine particle, and separates out finished product fine powder;The application solves the problem that existing dry method air classification grading process exists in the application of metal mine, such as large unit energy consumption of induced draft fan, equipment wear is serious, cannot continuous operation, structure is complex, is inconvenient to repair.

Description

Technical Field

[0001] This invention belongs to the field of mineral dispersion and sorting technology, and particularly relates to a low-energy-consumption mineral classifier and its design method. Background Technology

[0002] In the coarse and fine separation process of cake-like materials produced by bed grinding equipment, dry air classification is a highly efficient and low-consumption method. It mainly involves the dispersal of the cake-like materials, pre-selection of coarse particles, and fine selection of fine particles. Dispersal and coarse selection can be achieved by a V-type static air classifier, while fine selection can be achieved by a dynamic air classifier. Alternatively, a V-type static air classifier and a dynamic air classifier can be combined to form a multi-stage air classifier that simultaneously completes coarse and fine selection. The aforementioned known solutions are widely used in the building materials industry, but in the metal ore beneficiation industry, multi-stage screening and wet classification processes still dominate. The reasons for this are mainly twofold: (1) The density of metallic ores is generally greater than that of non-metallic ores in the building materials industry. For example, the true density of iron ore is about 3800 kg / m³. 3 The true density of limestone used in building materials is approximately 2700 kg / m³. 3 The difference between the two is 40%; (2) The fine-grained materials required for metal ores are usually coarser than those for non-metallic ores in the building materials industry. For example, low-grade magnetized suspension roasted iron powder requires a material residue of about 55% on an R80μm sieve, while stone powder for cement raw materials requires a residue of about 14% on an R80μm sieve, a difference of 293%.

[0003] Please see Figure 1 The diagram illustrates an existing dry sorting and grading system. A V-type static classifier is located at the bottom, and a dynamic classifier is at the top. The cake-shaped material to be sorted is fed into the V-type static classifier. The cake disperses by collisions between the dispersing and grading plates of the V-type static classifier. Coarse particles return to the bed grinding equipment for recirculation and grinding under gravity, while fine particles and fine powder enter the dynamic classifier from bottom to top under the air drag force (Stork force) generated by the induced draft fan. The sorted fine particles return to the bed grinding equipment for recirculation and grinding, while the fine powder is collected as a finished product by a dust collector. This process and equipment have few successful applications in the metal ore beneficiation industry, as mentioned above. Due to the difference in density and required particle size between metal ores, a much greater air drag force (Stork force) is needed to lift and sort the material compared to non-metallic minerals, leading to the following two problems: (1) A high-power induced draft fan is required to provide sufficient air traction (Stork force), which directly results in high unit power consumption of the induced draft fan, excessive overall energy consumption, and low output. (2) High air drag (Stork force) requires high wind speed. Excessive wind speed will aggravate the erosion and wear of the sorted material particles on the inside of the equipment. Metal ores are inherently more abrasive than non-metal ores, so the equipment life is difficult to guarantee and frequent shutdowns for maintenance are required. This is unacceptable in the metal beneficiation industry, which requires annual productivity.

[0004] Chinese Patent Publication No. CN102600923A discloses a magnetite final grinding system and its grinding method. It employs a multi-stage air classifier to disperse and classify the ore, obtaining four particle sizes: >3mm coarse particles, -3mm to 0.2mm fine particles (Grade 1), -3mm to 0.2mm fine particles (Grade 2), and <0.2mm fine particles. An induced draft fan provides airflow to the cyclone dust collector and the multi-stage air classifier. Investigations revealed that this multi-stage air classifier and system, when used in a steel company in Chengde, Hebei Province, could not effectively lift all finished materials even under full-load conditions, resulting in high power consumption and low output. Furthermore, severe equipment wear and discontinuous system operation were observed. Therefore, it was necessary to dismantle the equipment and system and rebuild it using a multi-stage screening and wet classification process.

[0005] Chinese Patent Publication No. CN105289838A discloses a weak magnetic separation-roasting-regrinding magnetic separation tailings recovery process. This process uses the overflow from a second-stage thickener as circulating water, and feeds the underflow from the second-stage thickener (55%–60% concentration) into a filter for filtration. The resulting filter cake is a coarse concentrate with a moisture content of 9%–13%, a grade of 25%–33%, and a yield of 15%–20%. This wet filter cake is then used as raw material for suspension magnetic roasting. However, the filter cake production process described in this patent is still a wet separation process, which fails to address the problems of high water consumption, high energy consumption, and the need for further drying of the filter cake inherent in wet separation processes.

[0006] As can be seen from the above, in the metal ore beneficiation industry, the existing wet beneficiation process has inherent problems such as high water consumption, high energy consumption, and serious pollution from wet tailings disposal; while the emerging dry air classification process has problems such as high unit energy consumption of induced draft fans, low output, and severe equipment wear and continuous operation due to the density of metal ores and the required particle size, which restricts its widespread application. Therefore, it is imperative to improve and optimize these issues.

[0007] To address the problems existing in the prior art, Chinese Patent Publication No. CN118751523A discloses a mining dispersion screening and grading machine and its design method. This invention is the first to adopt a top-down design concept, utilizing material gravity settling for transport and separation, thereby reducing system energy consumption and increasing output. However, the following technical problems still exist: First, in this patented design, the upper dynamic grading mode uses a high-speed rotating impeller to perform coarse material separation. The impeller separation requires a sufficient vertical grading distance to achieve effective separation, and the height range is relatively large. Simultaneously, the inverted conical ring screen and conical screen structure required in the lower part also increase the overall height requirement. This impeller grading mode necessitates that the device maintain a certain height; otherwise, the separation efficiency will be affected. Therefore, there is still considerable room for optimization in the device height.

[0008] Second, the impeller in this patent is the core dynamic component. The impeller consists of an upper ring plate, a lower arc plate, and impeller blades. During high-speed rotation, these components come into direct contact with materials containing high-hardness mineral particles. The impeller blades are particularly prone to wear. Whether they are straight or arc blades, their edges will gradually wear thin due to the high-speed impact of the material, resulting in a decrease in sorting efficiency and an imbalance in the power system.

[0009] Third, the dispersion and primary air separation components are made of a solid main shaft and a hollow shaft sleeve, which is relatively complex in structure and difficult to maintain.

[0010] The patented shaft system design is complex, specifically in the composite structure of hollow shaft and built-in main shaft used in the dispersion unit and primary air separation component. This nested shaft structure not only has high requirements for coaxiality and concentricity, but also has a complex bearing system, which means that multiple connecting parts need to be disassembled during maintenance. In particular, when the internal shaft fails, the external hollow shaft and related components must be removed first, increasing the difficulty of maintenance and downtime.

[0011] In summary, there is an urgent need for a low-energy-consumption classification device and design method that can effectively address the characteristics of metal ores and solve the aforementioned technical problems, thereby enabling dry air classification technology to be more widely used in the metal beneficiation industry. Summary of the Invention

[0012] The purpose of this invention is to provide a low-energy-consumption classifier for mining and its design method, so as to solve the problems mentioned in the background art regarding the existing dry air classification process in metal mining applications, such as high unit energy consumption of the induced draft fan, severe equipment wear and inability to operate continuously, and complex structure that is inconvenient to maintain.

[0013] To achieve the above objectives, the present invention provides the following technical solution: A low-energy-consumption classifier for mining includes an outer cavity and a dispersion unit, a primary low-resistance air separation unit, and a secondary air separation unit arranged coaxially from top to bottom. A feed pipe is provided at the upper end of the outer cavity, and the discharge port of the feed pipe is directly connected to the dispersion unit. The dispersion unit and the primary low-resistance air separation unit are located inside the outer cavity. The secondary air separation unit is connected to the bottom end of the outer cavity. A finished fine powder outlet is provided directly below the secondary air separation unit. The dispersion unit includes a material guiding system, a transmission drive system, and a material dispersion system, which are coaxially arranged from top to bottom within the support frame system, and are used to fully dissociate and disperse the cake-shaped material into single particles. The primary low-resistance air separation unit includes an air inlet system, a grading execution system, and a particle discharge system. The grading execution system adopts a static grading structure, including multiple coaxial inner and outer grading rings. The air inlet system forms a closed space through the lower section of the outer cavity and the primary air separation inlet. It is used to pre-sort the dissociated and dispersed single-particle materials, separating coarse and fine particles. The secondary air separation unit includes a secondary air separation shell and a secondary air separation component located inside the secondary air separation shell; the secondary air separation component includes a guiding system, a rotating drum system, a driving and support system, and a sealed discharge system; it is used to finely classify the fine particles after the primary air separation and finally separate the finished fine powder.

[0014] Preferably, the support frame system includes an upper section of the outer cavity and a steel frame, wherein the upper section of the outer cavity is a columnar hollow thin shell component, and the top is covered with a steel frame.

[0015] Preferably, the material guiding system includes a feed pipe, an upper buffer plate frame, an upper buffer plate, a side buffer plate frame, a side buffer plate, and a material dispersion constriction; wherein, the feed pipe includes a feed pipe inclined section and a feed pipe straight section, the feed pipe inclined section enters from one side of the upper cover plate of the upper section of the outer cavity and extends to the center of the upper section of the outer cavity, and the feed pipe straight section is connected to the feed pipe inclined section; the upper buffer plate frame is a thin-walled frustum shape, connected to the lower edge of the feed pipe straight section, and wear-resistant upper buffer plates are installed on the entire circumference of the inner wall of the upper buffer plate frame; the side buffer plate frame is connected to the outer edge of the upper buffer plate frame, and side buffer plates are installed on the entire circumference of the inner wall of the side buffer plate frame; the material dispersion constriction is connected to the lower edge of the side buffer plate frame.

[0016] Preferably, the transmission drive system includes a distributed unit drive bracket, a distributed unit drive assembly, an upper coupling, a distributed unit main shaft, and a bearing support assembly. The distributed unit drive bracket is located at the upper center of the steel frame, and the distributed unit drive assembly is mounted on the distributed unit drive bracket and connected to the distributed unit main shaft via the upper coupling. The bearing support assembly includes an upper bearing assembly on the main shaft, an upper bearing housing on the main shaft, a bushing, a lower bearing housing on the main shaft, and a lower bearing assembly on the main shaft. The upper bearing assembly is located inside the upper bearing housing on the main shaft, and the lower bearing assembly is located inside the lower bearing housing on the main shaft. The upper bearing housing and the lower bearing housing on the main shaft are connected by a bushing.

[0017] Preferably, the material dispersion system includes a hammer disc hub, a locking nut, a hammer disc support, a dispersion liner, dispersion hammers, hammer bolts, and a hammer disc retaining ring; wherein, the hammer disc hub is installed at the lower end of the main shaft of the dispersion unit by a locking nut; the hammer disc support is a ring structure and is welded to the hammer disc hub; the dispersion liner is a fan-shaped wear-resistant plate and is fixed to the inner side of the hammer disc support by hammer bolts; the dispersion hammers are fan-shaped wear-resistant blocks with one side protrusion and are evenly distributed in a ring on the outer side of the hammer disc support by hammer bolts; the hammer disc retaining ring is welded to the outer edge of the hammer disc support.

[0018] Preferably, the air intake system includes a lower section of the outer cavity, a primary air-selective inlet, and an inlet regulating valve; the lower section of the outer cavity is a volute-shaped shell, and the upper part of the lower section of the outer cavity is fixedly connected to the lower part of the upper section of the outer cavity to form a sealed cavity; one or more primary air-selective inlets are arranged circumferentially and tangentially in the lower section of the outer cavity; the air intake end of the primary air-selective inlet is connected to the inlet regulating valve, and the inlet regulating valve is connected to the circulating airflow or directly connected to the atmosphere.

[0019] Preferably, the grading execution system includes a fabric assembly and a grading ring assembly; the fabric assembly is disposed above the grading ring assembly, the inner cone of the fabric assembly overlaps and is connected to the first grading inner ring of the grading ring assembly, and the outer ring of the fabric assembly overlaps and is connected to the first grading outer ring of the grading ring assembly. The top center of the fabric assembly has a thin-walled conical inner cone for the fabric. The upper part of the inner cone is embedded inside the constriction of the dispersed material and adjacent to the hammer plate support. The outer ring of the fabric is a thin-walled ring in the shape of an inverted frustum. The upper edge of the outer ring is connected to the upper plate of the lower section of the outer cavity, forming the inlet part of the first-stage air separation channel between it and the inner cone of the fabric. The grading ring assembly includes multiple stacked inner and outer grading rings. The inner grading ring is a frustum-shaped thin-walled ring, and the outer grading ring is an inverted frustum-shaped thin-walled ring. The first inner grading ring is located directly below the inner cone of the fabric. The small diameter end of the first inner grading ring partially overlaps with the large diameter end of the inner cone of the fabric. Multiple coaxial inner grading rings are arranged sequentially from top to bottom, with diameters increasing and adjacent small and large diameter ends overlapping. Corresponding to the first inner grading ring is the first outer grading ring, located outside the first inner grading ring. The large diameter end of the first outer grading ring partially overlaps with the small diameter end of the outer ring of the fabric. Multiple coaxial outer grading rings are arranged sequentially from top to bottom, with diameters increasing and adjacent small and large diameter ends overlapping. The stacked inner and outer grading rings together form the sorting section of the tower-shaped primary air separation channel.

[0020] Preferably, the inner ring of the graded ring is designed to be adjustable, with an adjustment axis point set at the small diameter end of the inner ring. The adjustment plate of the inner ring rotates and / or translates with the inner ring through the adjustment axis point.

[0021] Preferably, the feed end of the finished fine powder outlet is connected to the lower plate of the frame, and the feed end of the fine particle outlet is connected to the inner edge of the lower end of the secondary air classifier guide ring; the feed end of the finished fine powder outlet and the feed end of the fine particle outlet are respectively a circle and annulus with the same center, the center of which is located on the axis of the air classifier cone shell, and the radius of the feed end of the fine particle outlet is larger than the radius of the feed end of the finished fine powder outlet.

[0022] Preferably, the guiding system includes a material guiding cone and a secondary air classifier guide ring disposed inside the air classifier cone shell; the material guiding cone is a hollow circular cone, arranged concentrically from top to bottom with the secondary air classifier guide ring; the secondary air classifier guide ring is located inside the air classifier cone shell and is a set of guide plates with an inclination angle evenly distributed around the circumference, with each guide plate forming an angle α with the radial direction of the circumference, wherein 30°≤α≤80°.

[0023] Preferably, the rotating cage system includes a two-stage air-separating rotating cage, which is located inside the two-stage air-separating guide ring and is concentric with the two-stage air-separating guide ring, and is in an inverted form; the core of the two-stage air-separating rotating cage is a hollow inverted cone-shaped inner cone, the upper end of which is connected to the upper frame plate formed by concentric annular plates, and the lower end is connected to the lower frame plate formed by concentric annular plates through a tie rod on the lower frame plate; rotating cage blades are evenly distributed vertically circumferentially between the upper frame plate and the lower frame plate along the outer edge of the rotating cage frame; One or more frame partitions are provided at equal intervals between the upper and lower frame plates. The frame partitions are connected to the inner cone of the rotating cage by partition rods. The inner cone of the rotating cage, the upper frame plate, the lower frame plate, and the frame partitions together constitute a complete rotating cage frame.

[0024] Preferably, the drive and support system includes a secondary air classifier drive bracket, a lower support, a lower steel frame, a rotating cage hub flange, a secondary air classifier main shaft, an upper bearing assembly on the secondary air classifier main shaft, an upper bearing chamber on the secondary air classifier main shaft, a lower bearing assembly on the secondary air classifier main shaft, a lower bearing chamber on the secondary air classifier main shaft, a lower coupling, and a rotating cage drive assembly; the lower end of the rotating cage frame is connected to the secondary air classifier main shaft via the rotating cage hub flange; the secondary air classifier main shaft is supported by the upper bearing assembly and the lower bearing assembly on the secondary air classifier main shaft; the lower end of the secondary air classifier main shaft is connected to the rotating cage drive assembly via the lower coupling. The rotating drum drive assembly is fixed on the secondary air classifier drive bracket. The secondary air classifier drive bracket and the lower bearing chamber of the secondary air classifier main shaft are fixed on the lower steel frame. The lower supports are connected to both ends of the lower steel frame.

[0025] Preferably, the sealed discharge system includes a sealing device, which is installed on the lower plane of the frame lower plate of the secondary air classifier rotary drum.

[0026] Preferably, the bottom end of the air separator cone is provided with a base plate.

[0027] Preferably, the classifier adopts an integrated structure, integrating the primary low-resistance air classifier unit and the secondary air classifier unit into one air classifier unit; the air classifier unit includes a secondary air classifier guide ring and a secondary air classifier rotating drum; the dispersion unit includes a dispersion hammer plate assembly; wherein, the dispersion unit and the air classifier unit are connected by a sleeve shaft structure, the sleeve shaft structure includes an external drive sleeve shaft and a secondary air classifier main shaft, the external drive sleeve shaft is connected to the dispersion hammer plate assembly, and the secondary air classifier main shaft is connected to the secondary air classifier rotating drum, so that the dispersion hammer plate assembly and the secondary air classifier rotating drum can be independently frequency-controlled.

[0028] Preferably, the upper part of the outer drive sleeve shaft is supported by an upper bearing assembly, which is located inside the upper bearing chamber of the sleeve shaft; the lower part of the outer drive sleeve shaft is supported by a lower bearing assembly, which is located inside the lower bearing chamber of the sleeve shaft; the dispersing hammer plate assembly includes a hammer disc hub, which is installed at the lower end of the outer drive sleeve shaft. The secondary air separation main shaft is supported by an upper bearing assembly and a lower bearing assembly. The upper bearing assembly and the lower bearing assembly are located inside the upper bearing chamber and the lower bearing chamber, respectively.

[0029] Preferably, the air separation unit further includes an upper section of the outer cavity and a material guiding air cone. The lower end of the upper section of the outer cavity is connected to the inner edge of the upper end of the secondary air separation guide ring. An upper seal is provided between the lower end of the material guiding air cone and the outer edge of the upper end of the secondary air separation drum. The lower end of the secondary air separation guide ring is connected to the particle discharge channel. The air separation unit includes a lower section of the outer cavity, which is a volute-shaped shell. The volute-shaped shell is concentrically surrounded outside the secondary air separation guide ring. The lower section of the outer cavity includes an air separation inlet. The inlet end of the air separation inlet is connected to an inlet regulating valve. The inlet regulating valve is connected to the circulating airflow or directly connected to the atmosphere.

[0030] A dry sorting and grading system using a low-energy-consumption mining classifier includes a hoist, a classifier, a flow stabilizing bin, a roller mill, a dust collector, an induced draft fan, and a finished product discharge device; the classifier is the aforementioned low-energy-consumption mining classifier, which includes, from top to bottom, a feed inlet, a dispersion unit, a primary low-resistance air separation unit, a secondary air separation unit, a coarse particle discharge outlet, a fine particle discharge outlet, and a finished fine powder outlet; The process involves several steps: First, fresh material is conveyed to a flow stabilizing bin via an elevator. The outlet of the flow stabilizing bin is connected to the inlet of a roller mill. Then, the cake-like material produced by the roller mill is conveyed to the inlet of a low-energy-consumption mining classifier via an elevator. Finally, the coarse particle outlet and fine particle outlet of the low-energy-consumption mining classifier are directly connected to the inlet of the flow stabilizing bin to form a circulating return process. The finished fine powder outlet of the low-energy-consumption mining classifier is sequentially connected to a dust collector and an induced draft fan. The dust collector then discharges the finished fine powder separated from the airflow to the finished product discharge device.

[0031] A design method for a low-energy-consumption classifier for mining includes the following steps: S1, Determine the characteristics of the material to be sorted (density) ) and material handling volume (C); S2. Based on experimental data and application experience, determine the air volume (Q) for air separation according to the characteristics of the materials to be separated and the material throughput. S3, based on the air volume (Q), the classifying interval (G), and the angle between the inner ring of the classifying ring and the horizontal plane ( ), calculate the velocity of the particles carried by the separating gas along the inner ring of the classification process ( );

[0032] In the formula: The diameter of the larger diameter end of the inner cone of the fabric, in meters; The diameter of the large-diameter end of the inner ring of the first-level classification is in meters. The diameter of the large-diameter end of the inner ring in the (N-1) grade classification is expressed in meters. N is the number of inner ring layers plus 1; S4, Calculate the theoretical cutting particle size when the grading path (overlapping area of ​​the inner ring of the grading) S=0. :

[0033] In the formula: The kinetic viscosity of the separated gas is expressed in Pa·s. The velocity of the particles carried by the separating gas along the inner ring of the classification process, expressed in m / s; The density of the sorted particles is expressed in kg / m³. 3 ; The angle between the inner ring of the graded ring and the horizontal plane is expressed in degrees. S5, the angle between the inner ring of the grade and the horizontal plane ranges from 15° to 80°. This is achieved by adjusting the grade path (S), grade spacing (G), and the angle between the inner ring and the horizontal plane. ), allowing particles to pass through the classification path in time ( The time it takes for the particles to fall onto the upper surface of the inner ring of the classification system under the influence of gravity is greater than the time it takes for the particles to fall. To achieve the optimal cutting particle size; To extend the effective particle sorting time, the grading path S is not 0. Therefore, the time for particles to pass through the grading path is: ; The time it takes for the particles to fall onto the upper surface of the inner ring of the classifier under the influence of gravity is: ; Right now .

[0034] Preferably, the method further includes a step of evaluating the total power consumption of the classifier based on the calculated parameters, wherein the total power consumption P of the classifier is... s Calculated using the following formula: .

[0035] Compared with the prior art, the beneficial effects of the present invention are: This invention systematically solves three core technical problems faced by existing dry air classification processes in metal ore applications: high energy consumption, severe equipment wear, and complex structure, through innovative static classification technology and a top-down material flow design concept. This invention replaces the dynamic impeller structure with static sorting components, optimizing material flow direction and airflow orientation, thus changing the working mode of traditional classifiers.

[0036] To address the issue of high energy consumption, this invention employs a top-to-bottom material flow path, utilizing material gravity settling to complete the sorting path. This eliminates the need for a large airflow from the induced draft fan to balance gravity, thus minimizing friction loss. Simultaneously, this invention utilizes a single-stage low-resistance air classifier unit comprised of inner and outer ring groups. The airflow enters tangentially and moves from top to bottom, performing sorting within a 360° circular area, effectively reducing local resistance loss. This single-stage low-resistance air classifier unit uses static sorting, eliminating the need for a dynamic impeller and thus reducing the energy consumption of the impeller drive. This results in lower airflow and pressure loss compared to systems with multi-stage air classifiers, significantly reducing the unit power consumption of the induced draft fan. For example, in the 1000t / h iron concentrate sorting, the total power consumption of a traditional sorting unit is 699kW, while the total power consumption of this invention's classifier is only 121kW, a reduction of approximately 75%, demonstrating excellent energy-saving performance.

[0037] To address equipment wear issues, this invention employs static sorting components, including a grading ring and a conical screen, to replace the impeller structure, eliminating erosion wear from dynamic components. The top-to-bottom material flow design reduces particle erosion wear along the system's ducts, chutes, and bends. Optimized airflow distribution reduces the erosion of equipment by localized high-speed airflow. This allows the equipment to avoid frequent downtime for maintenance in the high-productivity metal sorting and smelting industry, significantly improving operational reliability and service life.

[0038] To address the problem of complex structures and inconvenient maintenance, this invention replaces the combined structure of the impeller and inverted conical screen with a static air separation unit. Its lower, larger end can be effectively coupled with the secondary air separation unit, simplifying the overall structure. The shaft system design has been optimized, eliminating the complex composite structure of the hollow shaft and the built-in main shaft, reducing maintenance difficulty. The equipment height has been further reduced, facilitating installation and maintenance. These optimizations make the equipment structure simpler, maintenance more convenient, and reduce downtime for maintenance.

[0039] Through the aforementioned technological innovations, this invention not only effectively improves sorting efficiency, significantly reduces system energy consumption, and minimizes equipment wear, but also substantially reduces civil engineering height and construction costs. The reduced equipment height greatly compresses civil engineering costs, while the simplified equipment structure also lowers manufacturing costs. This maximizes economic benefits while improving equipment performance, laying a solid foundation for the widespread application of dry air classification technology in the metal beneficiation industry. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a traditional dry sorting and grading system; Figure 2 This is a schematic diagram of a dry sorting and grading system in a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a low-energy-consumption classifier for mining in a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the dispersion unit and the primary low-resistance air separation unit in the mining low-energy-consumption classifier in a preferred embodiment of the present invention; Figure 5 for Figure 4 View from direction A; Figure 6 This is a schematic diagram of the structure of the dispersion hammer plate assembly belonging to the dispersion unit in a preferred embodiment of the present invention; Figure 7 yes Figure 6 View from direction B; Figure 8 This is a schematic diagram of the structure of the secondary air separation unit in the mining low-energy classifier of the present invention in a preferred embodiment; Figure 9 This is a schematic diagram of the integrated low-energy-consumption mining classifier in a preferred embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of an integrated low-energy-consumption mining classifier that can produce fine powder, coarse particles, and fine particles according to a preferred embodiment of the present invention. Figure 11 This is a schematic diagram of the structure of an integrated low-energy mining classifier with screening function for separating fine powder, coarse particles and fine particles in a preferred embodiment of the present invention. Figure 12This is a schematic diagram of the cone screen structure in a preferred embodiment of the present invention; Figure 12-1 This is a schematic diagram of the sieve aperture in a preferred embodiment of the present invention; Figure 13 This is a schematic diagram of the adjustable structure of the hierarchical inner ring in a preferred embodiment of the present invention; Figure 14 This is a schematic diagram of the material and airflow direction of the mining low-energy classifier in a preferred embodiment of the present invention; Figure 15 A graph for energy consumption analysis of traditional sorting methods; Figure 16 This is a diagram illustrating the energy consumption analysis of the sorting method of the low-energy-consumption classifier for mining in a preferred embodiment of the present invention. Figure 17 This is a key dimension diagram of the cutting particle size of the primary low-resistance air separation unit of the mining low-energy-consumption classifier in a preferred embodiment of the present invention. Figure 17-1 This is a schematic diagram of the force analysis of material particle I in a mining low-energy classifier according to a preferred embodiment of the present invention.

[0041] In the diagram: 1. Foundation support; 2. Primary air separator inlet; 3. Lower section of outer cavity; 4. Upper section of outer cavity; 5. Steel frame; 6. Dispersion unit drive bracket; 7. Dispersion unit drive assembly; 8. Upper coupling; 9. Dispersion unit main shaft; 10. Upper bearing assembly of main shaft; 11. Upper bearing chamber of main shaft; 12. Inclined section of feed pipe; 13. Bushing; 14. Straight section of feed pipe; 15. Lower bearing chamber of main shaft; 16. Lower bearing assembly of main shaft; 17. Upper buffer plate frame; 18. Upper buffer plate; 19. Side buffer plate frame; 20. Side buffer plate; 21. Dispersion material constriction; 22. 23. Fabric inner cone; 24. Fabric outer ring; 25. Primary grading inner ring; 26. Primary grading outer ring; 27. Material collection outer ring; 28. Material collection inner ring; 29. ​​Coarse particle discharge channel; 30. Air inlet regulating valve; 31. Hammer disc hub; 32. Locking nut; 33. Hammer disc bracket; 34. Dispersion liner; 35. Dispersion hammer plate; 36. Hammer plate bolt; 37. Hammer disc retaining ring; 38. Fine particle discharge outlet; 49. Secondary air classifier drive bracket; 40. Lower support; 41. Lower steel frame; 42. Coarse particle discharge outlet; 43. Air classifier cone shell; 44. Secondary air classifier shell 44. Feed inlet; 45. Guide cone; 46. Inner cone of the rotating drum; 47. Upper frame plate; 48. Secondary air classifier guide ring; 49. Rotating drum blades; 50. Frame partition; 51. Partition tie rod; 52. Rotating drum hub flange; 53. Secondary air classifier main shaft; 54. Lower frame plate; 55. Lower frame plate tie rod; 56. Sealing device; 57. Rotating drum support; 58. Upper bearing assembly of the secondary air classifier main shaft; 59. Upper bearing chamber of the secondary air classifier main shaft; 60. Finished fine powder outlet; 61. Lower bearing assembly of the secondary air classifier main shaft; 62. Lower bearing chamber of the secondary air classifier main shaft; 63. Lower coupling. 63. Rotary drum drive assembly; 64. Pulley assembly; 65. External transmission sleeve shaft; 66. Upper bearing assembly on sleeve shaft; 67. Upper bearing chamber on sleeve shaft; 68. Lower bearing assembly on sleeve shaft; 69. Lower bearing chamber on sleeve shaft; 70. Upper seal; 71. Air classifier inlet; 72. Particle discharge channel; 73. Hollowed-out screening plate frame; 74. Conical screen; 75. Adjusting shaft point; 76. Grading inner ring adjusting plate; 01. Elevator; 02. Classifier; 03. Flow stabilizer; 04. Roller mill; 05. Dynamic classifier; 06. Dust collector; 07. Exhaust fan; 08. Finished product discharge device; Unfilled hollow arrows are schematic diagrams of airflow direction; Fully filled solid arrows are schematic diagrams of logistics flow; The arrows filled with dashed dots represent the flow direction of fine powder; The dashed arrows indicate the direction of airflow; Solid arrows indicate the direction of material movement; The black dots represent the material, and the size of the dots indicates the particle size of the material. Detailed Implementation

[0042] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0043] like Figures 1 to 17-1 As shown: First preferred embodiment: A low-energy-consumption classifier for mining includes an outer cavity and, from top to bottom, a feed pipe, a dispersion unit, a primary low-resistance air separation unit, a secondary air separation unit, and a finished fine powder discharge pipe, all coaxially arranged. The dispersion unit and the primary low-resistance air separation unit are located within the outer cavity. The secondary air separation unit is connected to the bottom of the outer cavity, and the feed pipe is located at the upper end of the outer cavity. The discharge port of the feed pipe is directly below the dispersion unit. The finished fine powder outlet 59 is located directly below the secondary air separation unit.

[0044] The pulverized cake-like material produced by the roller mill 04 (bed grinding equipment) passes sequentially from top to bottom through the feed pipe, the dispersion unit, the primary low-resistance air separation unit, and the secondary air separation unit, and is discharged from the finished fine powder outlet 59. Both the primary low-resistance air separation unit and the secondary air separation unit are equipped with particle discharge outlets. The dispersion unit is responsible for fully dispersing the cake-like material into individual particles. The primary low-resistance air separation unit is responsible for pre-sorting the dispersed individual particles, separating coarse and fine particles. The secondary air separation unit is responsible for finely classifying the fine particles after the primary air separation, ultimately separating the finished fine powder.

[0045] Please see Figure 4 , Figure 6 , Figure 7 The dispersion unit includes a support frame system, a material guiding system, a transmission drive system, and a material dispersion system. The cake-shaped material to be dispersed enters from the feed pipe, is guided by the material guiding system into the working area of ​​the material dispersion system, is fully disintegrated and dispersed under the action of the material dispersion system driven by the transmission drive system, and is then guided into the downstream primary low-resistance air separation unit through the dispersion material constriction 21.

[0046] The support frame system includes an upper section of the outer cavity 4 and a steel frame 5. The upper section of the outer cavity 4 is a columnar hollow thin shell with wear-resistant lining or wear-resistant coating on the inner wall. The top is covered with a steel frame 5, which is formed by welding H-beams to form a support platform. The material guiding system includes a feed pipe, an upper buffer plate frame 17, an upper buffer plate 18, a side buffer plate frame 19, a side buffer plate 10, and a material dispersion constriction 21. The feed pipe includes an inclined section 12 and a straight section 14. The inclined section 12 enters from one side of the upper cover plate of the upper section 4 of the outer cavity and extends to the center of the upper section 4 of the outer cavity. The inclined section 12 is connected to the straight section 14 and vertically guides the cake-shaped material to be dispersed to the dispersion area. The upper buffer plate frame 17 is a thin-walled frustum shape and is connected to the lower edge of the straight section 14 of the feed pipe. Wear-resistant upper buffer plates 18 are installed on the entire circumference of its inner wall. The side buffer plate frame 19 is connected to the outer edge of the upper buffer plate frame 17, and wear-resistant side buffer plates 10 are installed on the entire circumference of its inner wall. The material dispersion constriction 21 is connected to the lower edge of the side buffer plate frame 19 and serves as the outlet for the dispersed material.

[0047] The transmission drive system includes a distributed unit drive bracket 6, a distributed unit drive assembly 7, an upper coupling 8, a distributed unit main shaft 9, and a bearing support assembly. The distributed unit drive bracket 6 is located at the upper center of the steel frame 5. The distributed unit drive assembly 7 is mounted on the distributed unit drive bracket 6 and connected to the distributed unit main shaft 9 via the upper coupling 8. The bearing support assembly includes an upper bearing assembly 10, an upper bearing chamber 11, a bushing 13, a lower bearing chamber 15, and a lower bearing assembly 16. The upper bearing assembly 10 is located inside the upper bearing chamber 11, and the lower bearing assembly 16 is located inside the lower bearing chamber 15. The upper bearing chamber 11 and the lower bearing chamber 15 are connected as one unit via the bushing 13. The material dispersion system includes a hammer disc hub 30, a locking nut 31, a hammer disc support 32, a dispersion liner 33, dispersion hammers 34, hammer bolts 35, and a hammer disc retaining ring 36. The hammer disc hub 30 is installed at the lower end of the main shaft 9 of the dispersion unit and is axially fixed by the locking nut 31. The hammer disc support 32 has a ring-shaped structure and is connected to the hammer disc hub 30 by welding. The dispersion liner 33 adopts a fan-shaped wear-resistant plate design and is fixed to the inner area of ​​the hammer disc support 32 by the hammer bolts 35. The dispersion hammers 34 are fan-shaped wear-resistant blocks with a single-sided protrusion, and are evenly distributed in a ring on the outer area of ​​the hammer disc support 32 by the hammer bolts 35, forming a staggered structure. The hammer disc retaining ring 36 is welded to the outer edge of the hammer disc support 32, forming a ring-shaped protective structure that effectively prevents edge wear of the hammer disc support 32.

[0048] The dispersion area is formed by the confined space between the dispersion liner, the dispersion hammer, and the buffer plate assembly. The inclined section 12 of the feed pipe, the dispersion liner 33, the dispersion hammer 34, the upper buffer plate frame 17, the side buffer plate frame 19, and the dispersion material constriction 21 are all arranged on the same axis to ensure the uniformity of material dispersion and the stability of subsequent sorting.

[0049] The supporting frame system provides an installation support platform for the transmission drive system. The upper section 4 of the outer cavity is the main working area of ​​the dispersion unit, and the upper section 4 of the outer cavity provides an installation position for the bearing chamber. The steel frame 5 supports the dispersion unit drive bracket 6 and the dispersion unit drive assembly 7. The transmission drive system provides power and motion support for the material dispersion system. The dispersion unit drive assembly 7 transmits power to the hammer disc hub 30 through the upper coupling 8 and the dispersion unit main shaft 9. The hammer disc hub 30 drives the hammer disc bracket 32, the dispersion liner 33, and the dispersion hammer 34 to rotate, thereby realizing the function of dispersing the material. The material guiding system guides the material into the working area of ​​the material dispersion system. The feed pipe guides the pulverized cake-like material produced by the roller mill (material bed grinding equipment) to the confined space formed between the dispersion hammer and the buffer plate. The dispersion hammer disperses the material, while the upper buffer plate 18 and the side buffer plate 20 provide a rebound surface to fully dissociate the material. The dispersion material constriction 21 guides the dispersed material to the downstream first-stage low-resistance air classifier unit.

[0050] Please see Figure 4 , Figure 5 The primary low-resistance air separation unit is located directly below and coaxially arranged with the dispersing hammer assembly. The primary low-resistance air separation unit includes an air inlet system, a grading execution system, and a particle discharge system. These three systems form a hierarchical structure from top to bottom. The air inlet system is located on the periphery of the unit, forming a closed space through the lower section 3 of the outer cavity and the primary air separation inlet 2, providing an airflow environment for the sorting process. The grading execution system is located in the middle, consisting of a material distribution assembly and a grading ring assembly, connecting the upper and lower structures, and is the core area for material grading. The particle discharge system is located at the bottom, responsible for the orderly discharge of sorted materials through the inner and outer rings of the material collection and the coarse particle discharge channel 28. The three systems are spatially connected and functionally coordinated, ensuring uniform distribution of the sorting airflow and efficient material grading.

[0051] The primary low-resistance wind separator unit is entirely encapsulated within the lower section 3 of the outer cavity.

[0052] The air intake system includes a lower section 3 of the outer cavity, a primary air-selective inlet 2, and an inlet regulating valve 29. The lower section 3 is a volute-shaped shell, with its upper part fixedly connected to the lower part of the upper section 4 of the outer cavity, forming a sealed cavity. One or more primary air-selective inlets 2 are arranged tangentially around the lower section 3. The inlet end of each primary air-selective inlet 2 is connected to the inlet regulating valve 29, which connects to the circulating airflow or directly to the atmosphere to achieve airflow control. The center of the lower section 3 and the upper section 4 of the outer cavity are concentrically or eccentrically configured to ensure uniform distribution of the sorted airflow. Depending on the air intake method and air source, the center of the lower section 3 and the upper section 4 are either concentrically or eccentrically positioned. Specifically, the center of the lower section is concentrically positioned with the upper section for symmetrically introducing equal and balanced amounts of clean air. The center of the lower section of the outer cavity is eccentrically positioned relative to the upper section of the outer cavity; this is used to asymmetrically introduce unequal amounts of air-separated circulating airflow and clean air to meet process requirements.

[0053] The grading execution system includes a fabric assembly and a grading ring assembly. The fabric assembly has a thin-walled conical inner fabric cone 22 at its top center. The upper part of the inner fabric cone 22 is embedded inside the dispersion material constriction 21 and adjacent to the hammer disc support 32. The outer fabric ring 23 is an inverted frustum-shaped thin-walled ring. The upper edge of the outer fabric ring 23 connects to the upper plate of the lower section 3 of the outer cavity, forming the entrance portion of the first-stage air separation channel between it and the inner fabric cone 22. The grading ring assembly includes multiple stacked grading inner rings 24 and grading outer rings 25. The grading inner ring 24 is a frustum-shaped thin-walled ring, and the grading outer ring is an inverted frustum-shaped thin-walled ring. Directly below the inner fabric cone 22 is the first grading inner ring, whose small-diameter end partially overlaps with the large-diameter end of the inner fabric cone 22. Multiple coaxial grading inner rings are arranged sequentially from top to bottom, with diameters increasing and adjacent large and small diameter ends overlapping. Corresponding to the first inner grading ring is the first outer grading ring, outside of which the large-diameter end of the first outer grading ring partially overlaps with the small-diameter end of the fabric outer ring 23. Multiple coaxial outer grading rings are arranged sequentially from top to bottom, with diameters increasing and adjacent large and small ends partially overlapping. The stacked inner grading rings 24 and outer grading rings 25 together form the sorting section of the tower-type primary air separation channel.

[0054] Please see Figure 13 To further improve the control capability of the first-stage low-resistance air separation unit on the particle size of the material to be separated, the grading inner ring 24 can be designed as adjustable; an adjustment shaft point 75 is set at the small diameter end of the grading inner ring 24, and the grading inner ring adjustment plate 76 cooperates with the grading inner ring 24 through the adjustment shaft point 75. Figure 13 The dotted line on the left shows that the graded inner ring adjustment plate 76 can be rotated along the adjustment axis point 75 to adjust its angle. Figure 13The dotted line on the right shows that the grading inner ring adjustment plate 76 can be moved along the adjustment axis point 75 to adjust its length relative to the grading inner ring; thereby achieving precise control of the sorted particle size.

[0055] The particle discharge system includes an outer collecting ring 26, an inner collecting ring 27, and a coarse particle discharge channel 28. The inner collecting ring 27 is positioned directly below the inner ring of the final grading stage, and the outer collecting ring 26 is coaxially arranged outside the inner collecting ring 27. A foundation support 1 is provided circumferentially on the outer side of the outer collecting ring 26 to support the overall weight of the equipment. The outer collecting ring 26 is connected to the bottom plate of the lower section 3 of the outer cavity. An annular funnel is formed between the inner collecting ring 27 and the outer collecting ring 26. The end of the annular funnel is connected to the coarse particle discharge channel 28, and the bottom is connected to the inlet of the coarse particle discharge channel 28. Coarse particles are discharged through the coarse particle discharge channel 28. The coarse particle discharge channel 28 has a circular cross-section and surrounds the outer side of the secondary air separation unit. The upper side of the coarse particle discharge channel 28 is connected to the inner collecting ring 27, and the lower side is connected to the coarse particle outlet 41, forming a complete coarse particle discharge path.

[0056] Please see Figure 8 The secondary air separation unit is arranged from top to bottom with the primary low-resistance air separation unit mentioned above. The secondary air separation unit includes a secondary air separation housing and a secondary air separation component located inside the secondary air separation housing.

[0057] The secondary air classifier housing includes an air classifier cone 42, a fine particle outlet 37, and a finished fine powder outlet 59. The cavity formed by the air classifier cone 42 is the main sorting area. The upper part of the air classifier cone 42 is connected to the inner ring 27 of the primary low-resistance air classifier unit through the secondary air classifier housing inlet 43, introducing the dust-laden airflow after the primary low-resistance air classifier unit. The upper end of the fine particle outlet 37 is connected to the lower inner edge of the secondary air classifier guide ring 47, forming a dedicated discharge channel for fine particles. This design ensures that the sorted fine particles can be discharged smoothly under gravity, avoiding accumulation within the system.

[0058] The feed ends of the finished fine powder outlet 59 and the fine particle outlet 37 are respectively located at the bottom of the air classifier cone 42. The finished fine powder outlet 59 is located at the lower part of the air classifier cone 42, and its feed end is connected to the outlet of the lower frame plate 53. The fine particle outlet 37 is located at the lower side of the air classifier cone 42, and its feed end is connected to the inner edge of the lower end of the secondary air classifier guide ring 47. The feed ends of the finished fine powder outlet 59 and the fine particle outlet 37 are respectively a circle and an annulus with the same center. The center of the circle is located on the axis of the air classifier cone 42, and the radius of the feed end of the fine particle outlet 37 is larger than the radius of the feed end of the finished fine powder outlet 59, forming a structural layout of a central circle and an outer annulus.

[0059] The finished fine powder outlet 59 discharges the finished fine powder separated by the secondary air classification component. The fine particle outlet 37 is used to discharge the fine particles separated by the secondary air classification component.

[0060] The feed inlet 43 of the secondary air separator shell is connected to the discharge end of the inner ring 27 of the material collection system. The discharge end of the feed inlet 43 of the secondary air separator shell is connected to the feed inlet of the air separator cone 42 directly below, for introducing dust-laden airflow from the primary low-resistance air separator unit into the air separator cone 42. The bottom of the air separator cone 42 is provided with a bottom plate, which is used to seal the internal space of the air separator cone 42, maintain the stability of airflow pressure and direction in the secondary air separator area, and provide structural support for the air separator cone 42 to ensure the integrity of the airflow path during the material separation process.

[0061] The secondary air separation component includes a guiding system, a rotating drum system, a drive and support system, and a sealed discharge system.

[0062] The guiding system includes a material guiding cone 44 disposed inside the air-classifying cone shell 42. The material guiding cone 44 is a hollow circular cone, concentrically arranged from top to bottom with the secondary air-classifying guide ring 47. The material guiding cone 44 disperses and evenly distributes the material and airflow introduced into the secondary air-classifying shell inlet 43, ensuring that the material reaches a good distribution state before entering the sorting area. The secondary air-classifying guide ring 47 is located inside the air-classifying cone shell 42. The secondary air-classifying guide ring 47 is a group of guide plates with an inclination angle evenly distributed around the circumference. Each guide plate forms an angle α with the radial direction of the circumference, where 30°≤α≤80°. The air-classifying cone shell 42 and the secondary air-classifying guide ring 47 together converge and rectify the airflow introduced into the secondary air-classifying shell inlet 43, creating good airflow conditions for subsequent sorting.

[0063] The rotating cage system includes a two-stage air-separating rotating cage, which is located inside and concentric with the two-stage air-separating guide ring 47, and is in an inverted configuration. The core of the two-stage air-separating rotating cage is a hollow inverted cone-shaped inner cone 45. The upper end of the inner cone 45 is connected to a frame upper plate 46 composed of concentric annular plates, and the lower end is connected to a frame lower plate 53 composed of concentric annular plates via a frame lower plate tie rod 54. One or more frame partitions 49 are evenly spaced between the frame upper plate 46 and the frame lower plate 53, and the frame partitions 49 are connected to the inner cone 45 via partition tie rods 50. The inner cone 45, frame upper plate 46, frame lower plate 53, and frame partitions 49 together constitute a complete rotating cage frame. Rotating cage blades 48 are evenly distributed circumferentially between the frame upper plate 46 and the frame lower plate 53 along the outer edge of the rotating cage frame. These rotating drum blades 48 are key components for generating centrifugal force. During the rotation of the drum, centrifugal force is applied to the material to achieve effective separation of fine particles and fine powder.

[0064] The drive and support system includes a secondary air classifier drive bracket 38, a lower support 39, a lower steel frame 40, a rotating cage hub flange 51, a secondary air classifier main shaft 52, a rotating cage support 56, an upper bearing assembly 57, an upper bearing chamber 58, a lower bearing assembly 60, a lower bearing chamber 61, a lower coupling 62, and a rotating cage drive assembly 63. The lower end of the rotating cage frame is connected to the secondary air classifier main shaft 52 via the rotating cage hub flange 51. The secondary air classifier main shaft 52 is supported by the upper bearing assembly 57 and the lower bearing assembly 60, with the two bearing assemblies located in the upper bearing chamber 58 and the lower bearing chamber 61, respectively, ensuring the stability of the main shaft operation. The lower end of the secondary air classifier main shaft 52 is connected to the rotating cage drive assembly 63 via the lower coupling 62, and the rotating cage drive assembly 63 is fixed to the secondary air classifier drive bracket 38. The secondary air classifier drive bracket 38 and the lower bearing chamber 61 of the secondary air classifier main shaft are fixed to the lower steel frame 40. The lower supports 39 are connected to both ends of the lower steel frame 40, and the lower supports 39 transfer the dynamic and static loads of the entire secondary air classifier drum to the civil engineering foundation. The drum support 56 is located between the lower bearing chamber 61 of the secondary air classifier main shaft and the finished fine powder outlet 59 to reduce the swaying of the secondary air classifier drum.

[0065] The sealed discharge system includes a sealing device 55, which is installed on the lower plane of the frame lower plate 53 of the secondary air classifier drum. This device ensures a seal between the drum frame and the finished fine powder outlet. Fine particles will not leak into the finished fine powder, guaranteeing the classifier's sorting effect and environmental cleanliness.

[0066] Working principle: This low-energy-consumption classifier for mining adopts a top-to-bottom arrangement and a design concept that allows materials to move from top to bottom. It achieves efficient and low-energy-consumption material classification through four main working stages. The specific working principle is as follows: Phase 1: The cake-like material produced by the roller mill is vertically introduced into the working area of ​​the dispersion unit through the inclined section 12 and the straight section 14 of the feed pipe. The dispersion unit drive assembly 7 drives the main shaft 9 of the dispersion unit through the upper coupling 8, which drives the hammer disc hub 30, the hammer disc support 32, and the dispersion liner 33 and dispersion hammers 34 mounted on it to rotate at high speed. The cake-like material undergoes violent impact in the confined space formed between the high-speed rotating dispersion hammers 34 and the fixed upper buffer plate 18 and side buffer plate 20. Through the wear-resistant blocks protruding on one side of the dispersion hammers 34, and the staggered structure formed by multiple dispersion hammers evenly distributed in a ring on the hammer disc support near the outer edge, a strong impact and shearing action is generated on the material during rotation, achieving full dissociation and dispersion of the cake-like material. During the dispersion process, the material impacts back and forth between the dispersion hammer assembly and the buffer plate assembly, and is dissociated and broken up. The broken up material is introduced into the first-stage low-resistance air classifier unit below through the dispersion material constriction 21.

[0067] Phase Two: The dispersed material enters the grading execution system of the primary low-resistance air separation unit. The core of this system is the static grading inner and outer ring group, including the inner cone 22, the outer ring 23, the multi-layer grading inner ring 24, and the grading outer ring 25.

[0068] After the sorting airflow enters tangentially through the primary air classifier inlet 2 into the volute-shaped shell formed in the lower section 3 of the outer cavity, it first forms a swirling motion within the volute-shaped shell, achieving a uniform airflow distribution. Subsequently, the airflow undergoes rectification through multiple staged outer rings, further optimizing the flow velocity and direction, creating ideal airflow conditions for material sorting. During the encounter between the uniformly distributed material (after passing through the inner cone 22) and the rectified sorting airflow, complex multi-force coupling occurs. Under the influence of material inertia, material gravity, and airflow deflection, particles of different sizes exhibit different trajectories: Fine powder and fine particles, due to their small size and relatively low density, are more easily carried by the airflow and pass through the inner ring of the classification under the drag of the airflow, entering the subsequent secondary air classification unit 1. Coarse particles, due to their large size and high density, are significantly affected by inertial force and gravity, and are not easily carried by the airflow. They settle under the action of gravity and are discharged from the coarse particle discharge outlet 41 through the coarse particle discharge channel 28 via the annular funnel 1 formed by the inner ring 27 and the outer ring 26.

[0069] The primary low-resistance air separation unit, with its core consisting of inner and outer ring groups, fully utilizes the principle of material settling by its own weight to complete the separation path. This avoids the high energy consumption problem in traditional systems where a blower is needed to provide huge air drag to balance gravity and lift the material to be separated from bottom to top. It achieves efficient pre-separation while significantly reducing system resistance.

[0070] By adjusting the air inlet regulating valve 29, the flow rate and proportion of the incoming sorting air can be precisely controlled, ensuring the stability and adjustability of the pre-sorting effect and providing a more reasonable particle size distribution material flow for the subsequent secondary air classification unit.

[0071] Phase Three: The separating airflow carrying fine powder and fine particles enters the secondary air separation unit through the feed inlet 43 of the secondary air separation shell. Under the action of the guide cone 44, the dust-laden airflow is evenly distributed and then enters the separation area between the secondary air separation guide ring 47 and the rotating drum blades 48. The rotating drum drive assembly 63 drives the secondary air separation main shaft 52 through the lower coupling 62, causing the entire secondary air separation rotating drum to rotate at high speed. The rotating drum system adopts an inverted rotating drum frame design, including the inner cone 45 of the rotating drum, the upper frame plate 46, the lower frame plate 53, and the rotating drum blades 48.

[0072] In the secondary air separation process, the material-carrying airflow is separated under the action of centrifugal force generated by the secondary air separation component, air drag provided by the induced draft fan, and the material's own gravity. The centrifugal force on fine particles is greater than the air drag, and after being blocked by the air separation component, they are discharged from the fine particle outlet 37 under the action of gravity; the centrifugal force on finished fine powder is less than the air drag, and it passes through the air separation component and is discharged from the finished fine powder outlet 59; the sealing device is installed on the lower plane of the frame lower plate 53 and cooperates with the finished fine powder outlet 59. The lower outlet of the rotating frame cooperates with the above-mentioned finished fine powder outlet and is equipped with a sealing device to ensure the reliability of dynamic and static sealing.

[0073] Second preferred embodiment: Please see Figure 2 This embodiment provides a dry sorting and grading system using a low-energy mining classifier, comprising: a hoist 01, a classifier 02, a flow stabilizing bin 03, a roller mill 04, a dust collector 06, an induced draft fan 07, and a finished product discharge device 08; wherein, The classifier 02 is the mining low-energy classifier described in the first preferred embodiment. The mining low-energy classifier includes, from top to bottom, a feed inlet, a dispersion unit, a primary low-resistance air separation unit, a secondary air separation unit, a coarse particle outlet, a fine particle outlet, and a finished fine powder outlet.

[0074] Fresh material is conveyed to a flow stabilizing bin 03 via an elevator 01. The outlet of the flow stabilizing bin 03 is connected to the inlet of the roller mill 04. The flow stabilizing bin 03 provides a uniform and continuous material supply to the roller mill 04, preventing a sudden influx of large amounts of material into downstream equipment and causing impact. It also precisely controls the discharge flow rate of the material to meet the process requirements of the roller mill 04 and the system. The cake-shaped material produced by the roller mill 04 is conveyed to the inlet of the mining low-energy-consumption classifier via the elevator 01. The coarse particle outlet and fine particle outlet of the mining low-energy-consumption classifier are directly connected to the inlet of the flow stabilizing bin 03 to form a circulating return. The finished fine powder outlet of the mining low-energy-consumption classifier is sequentially connected to a dust collector 06 and an induced draft fan 07. The dust collector 07 discharges the finished fine powder separated from the airflow to the finished product discharge device 08.

[0075] The material handling process of the dry sorting and grading system in this embodiment is divided into two stages: The first stage is material conveying and grinding: the new material that has not been processed by the classifier is lifted by the elevator 01 to the stabilizing bin 03 to achieve material level adjustment and buffering; the stabilizing bin 03 controls the material to enter the roller mill 04 for bed grinding; the cake-shaped material produced by the roller mill 04 is then conveyed by the elevator 01 to the mining low-energy classifier. The second stage is grading and sorting: the cake-shaped material produced by the roller mill 04 is lifted to the mining low-energy-consumption classifier by the elevator 01; the mining low-energy-consumption classifier 0 includes a coarse particle discharge outlet 41, a fine particle discharge outlet 37, and a finished fine powder outlet 59. After the cake-shaped material is processed by the mining low-energy-consumption classifier, the coarse particles and fine particles are discharged from the coarse particle discharge outlet 41 and the fine particle discharge outlet 37 respectively, and directly enter the roller mill 04 to become the raw material for the cake-shaped material, which continues to be recycled into the mining low-energy-consumption classifier; the finished fine powder is discharged through the finished fine powder outlet 59 under the guidance of the induced draft fan 07, and is collected by the dust collector 06 and discharged to the finished product discharge device 08.

[0076] Figure 1 The image shows a prior art dry separation and grading system, including a dynamic air classifier 05 and a V-type static air classifier 02. It requires a high-power induced draft fan to provide air traction (Stork force) much greater than that required to lift non-metallic mineral materials to complete material lifting and separation. Excessive wind speed will exacerbate the erosion and wear of the separated material particles on the inside of the equipment. Since the abrasiveness of metallic minerals is inherently greater than that of non-metallic minerals, the equipment lifespan is difficult to guarantee, and frequent shutdowns for maintenance are required.

[0077] Third preferred embodiment: Based on the first embodiment described above, in order to further integrate the functions of the classifier, this embodiment adopts an integrated structure to integrate the primary low-resistance air classifier unit and the secondary air classifier unit into one air classifier unit; and adopts a sleeve shaft structure to achieve different optimal speed requirements for the dispersion hammer plate assembly and the secondary air classifier drum.

[0078] For further details, please refer to Figure 9 The primary low-resistance air classifier unit is simplified and merged into the secondary air classifier unit, and a sleeve shaft structure is adopted to achieve the different optimal speed requirements of the dispersion hammer assembly and the secondary air classifier drum. Figure 9This is a schematic diagram of the integrated low-energy-consumption classifier for mining. Specifically, the distributed unit drive assembly 7 is connected to the external drive shaft 65 via a pulley assembly 64. The upper part of the external drive shaft 65 is supported by an upper bearing assembly 66, which is located inside the upper bearing chamber 67. The lower part of the external drive shaft 65 is supported by a lower bearing assembly 68, which is located inside the lower bearing chamber 69. The hammer disc hub 30 is installed at the lower end of the external drive shaft 65, forming an independently driveable distributed hammer plate assembly. The rotating drum drive assembly 63 is connected to the secondary air classifier main shaft 52 via a lower coupling 62. The secondary air classifier main shaft 52 is supported by an upper bearing assembly 57 and a lower bearing assembly 60. The upper bearing assembly 57 and the lower bearing assembly 60 are located inside the upper bearing chamber 58 and the lower bearing chamber 61 of the secondary air classifier main shaft, respectively. The lower end of the secondary air classifier main shaft 52 is connected to the secondary air classifier rotating drum via a hub, forming an independently driveable air classifier rotating drum assembly. Both the dispersing hammer assembly and the air classifier rotating drum assembly are independently variable frequency speed regulated.

[0079] The air separation unit includes a lower section of the outer cavity, which is a volute-shaped shell concentrically surrounding the secondary air separation guide ring 47. The lower section of the outer cavity 3 includes an air separation inlet 71. Depending on the air intake method, the center of the lower section of the outer cavity can be concentric or eccentrically set with the upper section of the outer cavity 4. The inlet end of the air separation inlet 71 is connected to an inlet regulating valve 29, which connects to the circulating airflow or is directly connected to the atmosphere. The lower plate of the lower section of the outer cavity is connected to a foundation support 1 to support the weight of the equipment. The lower end of the upper section of the outer cavity 4 is connected to the inner edge of the upper end of the secondary air separation guide ring 47. An upper seal 70 is provided between the lower end of the material guide cone 44 and the outer edge of the upper end of the secondary air separation drum. The lower end of the secondary air separation guide ring 47 is connected to a particle discharge channel 72. The material to be sorted, dispersed by the dispersion unit, enters the sorting zone between the secondary air classifier drum and the secondary air classifier guide ring 47 through the channel formed by the upper section 4 of the outer cavity and the material guide cone 44.

[0080] Fourth preferred embodiment: Based on the first embodiment described above, please refer to Figure 10 This embodiment provides an integrated classifier that can produce fine powder, coarse particles, and fine particles. The lower end of the upper section 4 of the outer cavity is connected to the inner edge of the upper plate of the lower section of the outer cavity, and the lower end of the material guiding cone 44 is connected to the outer edge of the upper end of the secondary air classifier guide ring 47. The upper end of the fine particle discharge outlet 37 is connected to the inner edge of the lower end of the secondary air classifier guide ring 47, and the coarse particle discharge channel 28 is connected to the lower plate of the lower section of the outer cavity. The material to be sorted, dispersed by the dispersion unit, enters the primary sorting zone outside the secondary air classifier guide ring 47 through the channel formed by the upper section 4 of the outer cavity and the material guiding cone 44. This sorting zone can be equipped with a baffle plate to slow down the material flow rate and increase the residence time.

[0081] Fifth preferred embodiment: Based on the first embodiment described above, please refer to Figure 11 This embodiment provides an integrated classifier for separating fine powder, coarse particles, and fine particles with a screening function. The upper small-diameter end of the material guide cone 44 mates with the secondary air separator main shaft 52, and the lower large-diameter end mates with the outer edge of the upper plate 46 of the secondary air separator rotating frame. A perforated screening plate frame 73, similar in shape to the material guide cone 44, is fitted outside the material guide cone 44. The lower end of the screening plate frame 73 is connected to the upper outer edge of the secondary air separator guide ring 47, and multiple conical screens 74 are installed on the upper surface of the screening plate frame 73. Please refer to [link to relevant documentation]. Figure 12 and Figure 12-1 The conical screen 74 is a wear-resistant part, and its unfolded view is fan-shaped. Long strip round-end screen holes are also evenly distributed in two symmetrical areas on it. The radius of the round end of the long strip round-end screen hole is R1=0.5~10mm, the center of the round end represents the length of the screen hole L1=2~20R1, the center of the round end represents the width direction spacing between the screen holes G1=2.5~8R1, the center of the round end represents the length direction spacing G2=2.5~10R1, the distance from the center of the round end to the side edge S1=3~10R1, the distance from the center of the round end to the top edge S2=3~12R1, the distance between the two symmetrical areas S3=3~10R1, and the thickness of the conical screen 74 is t=2~30mm.

[0082] The above-mentioned cone screen structure can also be replaced Figure 4 The first-level low-resistance air separation unit shown forms a low-resistance combination of screening and air separation within its grading inner ring. Alternatively, it may consist only of a static grading inner ring assembly to mitigate potential wear and clogging of the screen structure.

[0083] Sixth preferred embodiment: A design method for a low-energy-consumption classifier for mining is based on the energy-saving concept of top-down gradient air classification, including a method for determining and adjusting the cutting particle size of a first-stage low-resistance air classification unit.

[0084] To further illustrate the energy-saving and consumption-reducing mechanism of the top-to-bottom arrangement of the present invention compared to the traditional method, please refer to... Figure 14 , Figure 15 , Figure 16 : Figure 15 The sorting unit consists of a traditional V-type static classifier and a fine dynamic classifier, arranged from bottom to top. The material to be sorted is fed into the V-type static classifier, where it is dispersed and pre-sorted. Then, it is carried from bottom to top by the air drag force (Stork force) generated by the induced draft fan into the dynamic classifier for fine sorting. The main movement stroke of the material includes: (1) The material is lifted from the foundation zero plane to the height H1 of the feeding layer plane of the V-type static classifier by a mechanical lifting device; (2) The material is lifted from the base zero plane to the height H2 of the selected dynamic classifier by air drag (since the material is pre-sorted during the process of falling at full height inside the V-type static classifier, it is still necessary to repeatedly lift the height H1 by air).

[0085] Without considering mechanical efficiency losses, the total power consumption P of the sorting unit composed of a traditional V-type static air classifier and a dynamic air classifier is... v It can be calculated that: (1) Power consumption P1 required for mechanical lifting height H1: 1) In the formula: The quantity of material to be sorted is expressed in t / h.

[0086] (2) Power consumption P2 required to lift the height H2 by air: 2) In the formula: The amount of air required to lift the material is expressed in kg / m³. 3 ; To increase the resistance generated by the material, the unit is Pa; To increase air density, the unit is kg / m³. 3 .

[0087] (3) Power consumption P3 to overcome the resistance generated by the rotation of the rotating drum of the dynamic classifier: 3) In the formula: The resistance generated by the rotation of the drum is measured in Pa.

[0088] (4) Total power consumption P required by traditional sorting unit v : 4) Figure 16 The sorting unit of the low-energy-consumption classifier for mining in this invention adopts a top-to-bottom arrangement. The material to be sorted is directly fed into the low-energy-consumption classifier, dispersed and pre-sorted inside, and then falls freely under gravity to the secondary air separation unit for fine sorting. The main movement stroke of the material includes: (1) The material is lifted from the foundation zero plane to the height H3 of the feeding layer plane of the mining low-energy classifier by the mechanical lifting device; (2) The height H3 of the material moving from the feeding layer plane of the low-energy classifier to the zero plane of the foundation under the action of gravity.

[0089] Since the stroke (2) is mainly completed under the action of gravity, only the power consumption of the first-stage low-resistance air separation unit needs to be considered. Without considering mechanical efficiency losses, the total power consumption P of the sorting unit composed of the mine-use low-energy-consumption classifier of this invention is... s It can be calculated that: (1) Power consumption P4 required for mechanical lifting height H3: 5) (2) Power consumption P5 of the first-stage low-resistance unit: 6) In the formula: The amount of air required to lift the material is expressed in kg / m³. 3 ; The resistance generated for the primary low-resistance air separation unit is measured in Pa. To increase air density, the unit is kg / m³. 3 .

[0090] (3) Power consumption P6 to overcome the resistance generated by the rotation of the secondary air separator: 7) (4) The total power consumption P required by the sorting unit of the present invention s : 8) Specifically, taking 1000t / h iron concentrate to be sorted as an example, the above parameters are shown in Table 1 below: Table 1 Specifications for 1000t / h

[0091] Calculate the total power consumption P required by the traditional sorting unit from 4). v :

[0092] Calculate the total power consumption P required by the sorting unit composed of the low-energy-consumption classifier for mining according to the present invention (8). s :

[0093] As can be seen from the above calculations, compared with the 699kW unit hour power consumption of the traditional sorting unit, the sorting unit composed of the mining low-energy classifier of this invention has a unit hour power consumption of only 121kW, a reduction of about 75%, which has a very good energy-saving effect.

[0094] To further explain the energy-saving principle and implementation scheme of the low-energy-consumption mine classifier of the present invention, as well as the method for determining and adjusting the particle size of low-resistance air separation cutting, please refer to [link to relevant documentation]. Figure 17 : The mining low-energy classifier and system proposes a top-down low-resistance air classification energy-saving concept. Based on this concept, a built-in primary low-resistance classification unit replaces the traditional V-type static air classifier and is located entirely at the top, while the secondary air classification unit is located at the bottom. Coarse particles, fine particles, and a mixture of fine powder are fed into the classifier from the top, dispersed by the dispersion unit, and then enter the separation zone of the primary low-resistance air classification unit. Figure 17-1 For the force analysis of the material, the force is gravity in the vertical direction. It is subjected to air drag along the inner ring direction of the grade. Assuming the sorted particles are spherical, then gravity... Represented as: 9) In the formula: The diameter of the sorted particles is in meters (m). The density of the sorted particles is expressed in kg / m³. 3 .

[0095] air drag Represented as: 10) In the formula: The kinetic viscosity of the separated gas is expressed in Pa·s. The velocity of the particles carried by the separating gas along the inner ring of the classification system is expressed in m / s.

[0096] The theoretical cutting particle size when S=0 in the graded path (overlapping region of the inner ring of the graded path) can be obtained from equations 9 and 10. 11) In the formula: The angle between the inner ring of the graded ring and the horizontal plane is expressed in degrees.

[0097] To extend the effective particle sorting time, the grading path S is not 0. Therefore, the time for particles to pass through the grading path is: 12) The time it takes for the particles to fall onto the upper surface of the inner ring of the classifier under the influence of gravity is: 13) From equations 12) and 13), it can be seen that, based on the theoretical cutting particle size, the grading path S, the grading spacing G (the spacing between the inner rings of the grading), and the included angle can be adjusted. , making ,Right now This can increase the sorting time and further reduce the cutting particle size.

[0098] To further illustrate the design method of the first-stage low-resistance wind separation unit of the present invention, please refer to [link / reference needed]. Figure 17 The main process structure parameters are set as follows: Based on experimental data and application experience, once the characteristics of the materials to be sorted and the material throughput are determined, the air volume for air separation is... Also It should be determined that the velocity of the particles carried by the separating gas along the inner ring of the classification process is... for: 14) In the formula: The diameter of the larger diameter end of the inner cone 22 of the fabric is in meters. The diameter of the 24 major diameter ends of the first-level inner ring is measured in meters. The diameter of the large-diameter end of the inner ring of the (N-1) grade classification is in meters. N is the number of inner ring layers in the hierarchy plus 1.

[0099] Angle between the inner ring of the grade and the horizontal plane : 15) Length L of the outer ring busbar in the graded series: 16) Hierarchical Path : 17) Grading spacing G: 18) The ratio of the outer diameter of adjacent graded outer rings: 19) In summary, this invention, through the introduction of a low-energy-consumption classifier and its design method for mining, adopts a top-to-bottom arrangement for the entire machine. Combined with low-resistance separation and energy-saving screening concepts, it effectively improves separation efficiency, significantly reduces system energy consumption, minimizes equipment wear, and lowers civil engineering height and construction costs, thus further enhancing overall benefits. Therefore, it can replace the multi-stage air classifier formed by the original V-type static and dynamic air classifiers, promoting the advancement of dry air separation technology in the mining industry.

[0100] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-energy-consumption classifier for mining, characterized in that, The system includes an outer cavity and a dispersion unit, a primary low-resistance air classifier, and a secondary air classifier arranged coaxially from top to bottom. A feed pipe is located at the upper end of the outer cavity, and the outlet of the feed pipe is directly below the dispersion unit. The dispersion unit and the primary low-resistance air classifier are located within the outer cavity. The secondary air classifier is connected to the bottom of the outer cavity. A finished fine powder outlet is located directly below the secondary air classifier. The dispersion unit includes a material guiding system, a transmission drive system, and a material dispersion system arranged coaxially from top to bottom within the support frame system, used to fully dissociate and disperse the cake-shaped material into single particles. The primary low-resistance air separation unit includes an air inlet system, a grading execution system, and a particle discharge system. The grading execution system adopts a static grading structure. The air inlet system forms a closed space through the lower section of the outer cavity and the primary air separation air inlet. It is used to pre-sort the dissociated and dispersed single-particle materials to separate coarse and fine particles. The secondary air separation unit includes a secondary air separation shell and a secondary air separation component disposed inside the secondary air separation shell; the secondary air separation component includes a guiding system, a rotating drum system, a driving and supporting system, and a sealed discharge system; it is used to finely classify the fine particles after the primary air separation and finally separate the finished fine powder; in, The graded execution system includes a fabric assembly and a graded ring assembly; the fabric assembly is positioned above the graded ring assembly, the inner cone of the fabric assembly overlaps and is connected to the first graded inner ring of the graded ring assembly, and the outer ring of the fabric assembly overlaps and is connected to the first graded outer ring of the graded ring assembly. The top center of the fabric assembly has a thin-walled conical inner cone for the fabric. The upper part of the inner cone is embedded inside the constriction of the dispersed material and adjacent to the hammer plate support. The outer ring of the fabric is a thin-walled ring in the shape of an inverted frustum. The upper edge of the outer ring is connected to the upper plate of the lower section of the outer cavity, forming the inlet part of the first-stage air separation channel between it and the inner cone of the fabric. The grading ring assembly includes multiple stacked inner and outer grading rings. The inner grading ring is a frustum-shaped thin-walled ring, and the outer grading ring is an inverted frustum-shaped thin-walled ring. The first inner grading ring is located directly below the inner cone of the fabric, with its small-diameter end partially overlapping the large-diameter end of the inner cone. Multiple coaxial inner grading rings are arranged sequentially from top to bottom, with diameters increasing and adjacent small and large diameter ends overlapping. Corresponding to the first inner grading ring is the first outer grading ring, with its large-diameter end partially overlapping the small-diameter end of the outer ring. Multiple coaxial outer grading rings are arranged sequentially from top to bottom, with diameters increasing and adjacent small and large diameter ends overlapping. The stacked inner and outer grading rings together form the sorting section of a tower-shaped primary air-separation channel. The graded inner ring is adjustable, with an adjustment axis point set at the small diameter end of the graded inner ring. The graded inner ring adjustment plate rotates and / or translates with the graded inner ring through the adjustment axis point. The guiding system includes a material guiding cone and a secondary air classifier guide ring disposed inside the air classifier cone shell; the material guiding cone is a hollow circular cone, and is arranged concentrically from top to bottom with the secondary air classifier guide ring; the secondary air classifier guide ring is located inside the air classifier cone shell and is a set of guide plates with an inclination angle evenly distributed around the circumference, with each guide plate forming an angle α with the radial direction of the circumference, where 30°≤α≤80°; The rotating cage system includes a two-stage air-separating rotating cage, which is located inside the two-stage air-separating guide ring and is concentric with the two-stage air-separating guide ring, and is in an inverted form. The core of the two-stage air-separating rotating cage is a hollow inverted cone-shaped inner cone. The upper end of the inner cone is connected to the upper frame plate composed of concentric annular plates, and the lower end is connected to the lower frame plate composed of concentric annular plates through a tie rod. Rotating cage blades are evenly distributed vertically circumferentially between the upper frame plate and the lower frame plate along the outer edge of the rotating cage frame. One or more frame partitions are provided at equal intervals between the upper and lower frame plates. The frame partitions are connected to the inner cone of the rotating cage by partition rods. The inner cone of the rotating cage, the upper frame plate, the lower frame plate, and the frame partitions together constitute a complete rotating cage frame.

2. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The support frame system includes an upper section of the outer cavity and a steel frame. The upper section of the outer cavity is a columnar hollow thin shell with a steel frame laid on top.

3. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The material guiding system includes a feed pipe, an upper buffer plate frame, an upper buffer plate, a side buffer plate frame, a side buffer plate, and a material dispersion constriction. The feed pipe includes an inclined section and a straight section. The inclined section enters from one side of the upper cover plate of the upper section of the outer cavity and extends to the center of the upper section. The straight section is connected to the inclined section. The upper buffer plate frame is a thin-walled frustum shape and is connected to the lower edge of the straight section of the feed pipe. Wear-resistant upper buffer plates are installed on the entire circumference of the inner wall of the upper buffer plate frame. The side buffer plate frame is connected to the outer edge of the upper buffer plate frame, and side buffer plates are installed on the entire circumference of the inner wall of the side buffer plate frame. The material dispersion constriction is connected to the lower edge of the side buffer plate frame.

4. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The transmission drive system includes a distributed unit drive bracket, a distributed unit drive assembly, an upper coupling, a distributed unit main shaft, and a bearing support assembly. The distributed unit drive bracket is located at the upper center of the steel frame, and the distributed unit drive assembly is mounted on the distributed unit drive bracket and connected to the distributed unit main shaft via the upper coupling. The bearing support assembly includes an upper bearing assembly on the main shaft, an upper bearing housing on the main shaft, a bushing, a lower bearing housing on the main shaft, and a lower bearing assembly on the main shaft. The upper bearing assembly is located inside the upper bearing housing on the main shaft, and the lower bearing assembly is located inside the lower bearing housing on the main shaft. The upper and lower bearing housings on the main shaft are connected by a bushing.

5. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The material dispersion system includes a hammer disc hub, a locking nut, a hammer disc support, a dispersion liner, dispersion hammers, hammer bolts, and a hammer disc retaining ring. The hammer disc hub is mounted to the lower end of the dispersion unit's main shaft via a locking nut. The hammer disc support is a ring structure welded to the hammer disc hub. The dispersion liner is a fan-shaped wear-resistant plate, fixed to the inner side of the hammer disc support via hammer bolts. The dispersion hammers are fan-shaped wear-resistant blocks with a single-sided protrusion, evenly distributed in a ring on the outer side of the hammer disc support via hammer bolts. The hammer disc retaining ring is welded to the outer edge of the hammer disc support.

6. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The air intake system includes a lower section of the outer cavity, a primary air selection inlet, and an inlet regulating valve. The lower section of the outer cavity is a volute-shaped shell, and the upper part of the lower section of the outer cavity is fixedly connected to the lower part of the upper section of the outer cavity to form a sealed cavity. One or more primary air selection inlets are arranged circumferentially and tangentially in the lower section of the outer cavity. The air intake end of the primary air selection inlet is connected to the inlet regulating valve, which is connected to the circulating airflow or directly connected to the atmosphere.

7. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The feed end of the finished fine powder outlet is connected to the lower plate of the frame, and the feed end of the fine particle outlet is connected to the inner edge of the lower end of the secondary air classifier guide ring; the feed end of the finished fine powder outlet and the feed end of the fine particle outlet are circles and rings with the same center, respectively, with the center located on the axis of the air classifier cone shell, and the radius of the feed end of the fine particle outlet is larger than the radius of the feed end of the finished fine powder outlet.

8. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The drive and support system includes a secondary air classifier drive bracket, a lower support, a lower steel frame, a rotating cage hub flange, a secondary air classifier main shaft, a rotating cage support, an upper bearing assembly on the secondary air classifier main shaft, an upper bearing chamber on the secondary air classifier main shaft, a lower bearing assembly on the secondary air classifier main shaft, a lower bearing chamber on the secondary air classifier main shaft, a lower coupling, and a rotating cage drive assembly. The lower end of the rotating cage frame is connected to the secondary air classifier main shaft via the rotating cage hub flange. The secondary air classifier main shaft is supported by the upper and lower bearing assemblies of the secondary air classifier main shaft. The lower end of the secondary air classifier main shaft is connected to the rotating cage drive assembly via the lower coupling. The rotating drum drive assembly is fixed on the secondary air classifier drive bracket. The secondary air classifier drive bracket and the lower bearing chamber of the secondary air classifier main shaft are fixed on the lower steel frame. The lower supports are connected to both ends of the lower steel frame.

9. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The sealed discharge system includes a sealing device, which is installed on the lower plane of the frame lower plate of the secondary air classifier rotary drum.

10. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The bottom end of the air separator cone is provided with a base plate.

11. The low-energy-consumption classifier for mining according to claim 1, characterized in that, The classifier adopts an integrated structure, which integrates the primary low-resistance air classifier unit and the secondary air classifier unit into one air classifier unit; the dispersion unit includes a dispersion hammer plate assembly; wherein, the dispersion unit and the air classifier unit are connected by a sleeve shaft structure, the sleeve shaft structure includes an external drive sleeve shaft and a secondary air classifier main shaft, the external drive sleeve shaft is connected to the dispersion hammer plate assembly, and the secondary air classifier main shaft is connected to the secondary air classifier rotating drum, so that the dispersion hammer plate assembly and the secondary air classifier rotating drum can be independently frequency-controlled.

12. The low-energy-consumption classifier for mining according to claim 11, characterized in that, The upper part of the external transmission sleeve shaft is supported by an upper bearing assembly located inside the upper bearing chamber, and the lower part of the external transmission sleeve shaft is supported by a lower bearing assembly located inside the lower bearing chamber; the dispersing hammer plate assembly includes a hammer disc hub, which is installed at the lower end of the external transmission sleeve shaft; The secondary air separation main shaft is supported by an upper bearing assembly and a lower bearing assembly. The upper bearing assembly and the lower bearing assembly are located inside the upper bearing chamber and the lower bearing chamber, respectively.

13. The low-energy-consumption classifier for mining according to claim 11, characterized in that, The air separation unit also includes an upper section of an outer cavity, the lower end of which is connected to the inner edge of the upper end of the secondary air separation guide ring, an upper seal is provided between the lower end of the material guiding cone and the outer edge of the upper end of the secondary air separation drum, and the lower end of the secondary air separation guide ring is connected to the particle discharge channel. The air separation unit includes a lower section of an outer cavity, which is a volute-shaped shell. The volute-shaped shell is concentrically surrounded outside the secondary air separation guide ring. The lower section of the outer cavity includes an air separation inlet. The inlet end of the air separation inlet is connected to an inlet regulating valve. The inlet regulating valve is connected to the circulating airflow or directly connected to the atmosphere.

14. A dry sorting and grading system using a low-energy-consumption mining classifier, comprising a hoist, a classifier, a flow stabilizing bin, a roller mill, a dust collector, an induced draft fan, and a finished product discharge device; characterized in that, The classifier is the mining low-energy classifier as described in any one of claims 1 to 13, wherein the feed inlet, dispersion unit, primary low-resistance air separation unit, secondary air separation unit, coarse particle outlet, fine particle outlet and finished fine powder outlet of the mining low-energy classifier are arranged sequentially from top to bottom. The process involves several steps: First, fresh material is conveyed to a flow stabilizing bin via an elevator. The outlet of the flow stabilizing bin is connected to the inlet of a roller mill. Then, the cake-like material produced by the roller mill is conveyed to the inlet of a low-energy-consumption mining classifier via an elevator. Finally, the coarse particle outlet and fine particle outlet of the low-energy-consumption mining classifier are directly connected to the inlet of the flow stabilizing bin to form a circulating return process. The finished fine powder outlet of the low-energy-consumption mining classifier is sequentially connected to a dust collector and an induced draft fan. The dust collector then discharges the finished fine powder separated from the airflow to the finished product discharge device.

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