Air classifier and classification separation system

Abstract

The utility model discloses an air classifier and a grading separation system, the air classifier comprises a machine shell and a grading wheel, the top of the machine shell is provided with a feeding port, the bottom of the machine shell is provided with a first discharging port, the side face of the machine shell is provided with a second discharging port, the grading wheel is arranged in the machine shell, the grading wheel comprises a rotating cage, and the rotating cage is arranged on the machine shell. The blades of the rotating cage comprise the first blades and the second blades, the width of the first blades is larger than that of the second blades, and the multiple first blades and the multiple second blades are arranged in a staggered mode in the circumferential direction of the rotating cage. The air classifier disclosed by the utility model is simple in structure and has better separation precision and separation efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium battery recycling technical field especially is related to an air classifier and grading separation system. BACKGROUND

[0002] In recent years, the rapid update iteration of lithium battery technology promotes the vigorous development of positive electrode material enterprises. At present, the cost reduction of the industry manufacturers mainly starts from the raw material cost reduction and process optimization. In the positive electrode material mass production process, the fluidized bed airflow mill can be used for preparing superhard, superfine and superpure products, and is an important equipment for crushing single crystal particles. In this process, the particle size of the dust collection material is too small, and the treatment equipment for the ultrafine particles of the dust collection material in the related technology has low separation precision and separation efficiency. SUMMARY

[0003] The utility model discloses at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide an air classifier, which has simple structure, can reduce the production cost of the equipment, and has good separation precision and separation efficiency.

[0004] The air classifier according to the utility model embodiment comprises: a shell and a grading wheel, the top of the shell is provided with a feeding port, the bottom of the shell is provided with a first discharging port, the side surface of the shell is provided with a second discharging port, the grading wheel is arranged in the shell, the grading wheel comprises a rotating cage, the blades of the rotating cage comprise first blades and second blades, the width of the first blades is greater than the width of the second blades, and a plurality of the first blades and a plurality of the second blades are arranged staggeredly in the circumferential direction of the rotating cage.

[0005] The air classifier according to the utility model embodiment has simple structure, can reduce the production cost of the equipment, and the staggered blade structure can make the airflow more uniform and stable, which is helpful for further screening of small particles in the stable airflow, thereby improving the accuracy and efficiency of grading.

[0006] In addition, the air classifier according to the utility model can also have the following additional technical features:

[0007] In some embodiments of the utility model, in the radial direction of the rotating cage, the distance H1 between the outer edge of the second blade and the outer edge of the rotating cage satisfies: 3mm≤H1≤7mm.

[0008] In some embodiments of the utility model, the shell comprises a volute and a conical hopper connected to the lower end of the volute, the grading wheel is located in the volute, and the first discharging port is located at the bottom of the conical hopper.

[0009] In some embodiments of the utility model, the rotation axis of the rotating cage extends along the horizontal direction, and the second discharge port is located on the rotation axis.

[0010] In some embodiments of the utility model, the blades of the rotating cage are arc-shaped blades, and the axis of the arc-shaped blades is parallel to the rotation axis of the rotating cage.

[0011] In some embodiments of the utility model, in the axial direction, the length L1 of the first blade and the length L2 of the second blade satisfy: 0.78≤L2 / L1≤0.85.

[0012] In some embodiments of the utility model, the rotating cage further comprises a first annular plate and a second annular plate, the first blade is connected between the first annular plate and the second annular plate, the second blade comprises opposite free ends and fixed ends, and the fixed ends of the second blades on both sides of the first blade are respectively mounted on the first annular plate and the second annular plate.

[0013] In some embodiments of the utility model, the sum N of the number of the plurality of first blades and the plurality of second blades satisfies: 30≤N≤35.

[0014] In some embodiments of the utility model, the outer edge of the blade of the rotating cage is provided with a disturbance rod, and the disturbance rod extends along the radial direction of the rotating cage.

[0015] In some embodiments of the utility model, the side surface of the shell is further provided with a first air inlet, and in the up-down direction, the first air inlet is located between the classification wheel and the first discharge port.

[0016] The utility model further provides a classification separation system of the air classifier with the above-mentioned embodiments.

[0017] The classification separation system according to the utility model embodiments comprises a first-stage classification crushing device and a second-stage classification separation device, the first-stage classification crushing device comprises a crushing device and a separator, the crushing device is used for crushing materials, the separator is communicated with the crushing device, the separator is used for collecting the crushed materials and separating the materials into qualified materials meeting a first condition and first dust collection materials meeting a second condition, the qualified materials are conveyed from a first material outlet, and the first dust collection materials are conveyed towards a second material outlet, wherein the particle size of the qualified materials is greater than that of the first dust collection materials; the second-stage classification separation device comprises at least one air classifier, wherein when the air classifier is multiple, the feeding port of one of the adjacent two air classifiers is communicated with the second material outlet, and the second discharge port is communicated with the feeding port of another air classifier.

[0018] According to the classification separation system of the embodiment of the utility model, can make material orderly flow between multiple air classifiers which are communicated in sequence, layer by layer screening, until realizing ideal classification state, classifying material according to required precision standard, so as to be put into subsequent corresponding links such as chemical synthesis, material preparation, product processing etc. and utilize efficiently.

[0019] The additional aspects and advantages of the utility model will be partially given in the following description, some will become obvious from the following description, or be understood by the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the utility model will become apparent and more readily appreciated from the following description of the embodiments, with reference to the following drawings, in which:

[0021] Figure 1 It is the structure schematic diagram of air classifier according to some embodiments of the utility model.

[0022] Figure 2 It is the structure schematic diagram of classification separation system according to some embodiments of the utility model (the wireframe of reference number 1000 and reference number 2000 in the drawing is only for distinguishing first stage classification crushing device and second stage classification separation device, frame first stage classification crushing device and second stage classification separation device in wireframe, and wireframe is not entity structure).

[0023] Figure 3 It is the structure schematic diagram of rotary cage according to some embodiments of the utility model.

[0024] Figure 4 It is the sectional view of rotary cage according to some embodiments of the utility model.

[0025] Figure 5 It is the perspective view of rotary cage (with disturbing rod) according to some embodiments of the utility model.

[0026] Reference signs:

[0027] 100, air classifier;

[0028] 1, shell;11, volute;12, conical funnel;13, first discharge port;14, second discharge port;15, first air inlet;16, feed inlet;

[0029] 2, classification wheel;21, rotary cage;20, blade;211, first blade;212, second blade;22, first annular plate;23, second annular plate;24, disturbing rod;

[0030] 10000, classification separation system;

[0031] 1000, first stage classification crushing device; 200, crushing device; 300, separator;

[0032] 2000, second stage classification separation device; 400, dust collector. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are used only for the purpose of explaining the present application, and should not be understood as a limitation of the present application.

[0034] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0035] In the description of the present application, it should be noted that, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connection" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In recent years, the rapid update and iteration of lithium battery technology has promoted the vigorous development of positive electrode material enterprises. At present, the manufacturers in the industry mainly reduce the cost from two aspects of raw material cost reduction and process optimization. In the positive electrode material mass production process, the fluidized bed jet mill can be used to prepare super-hard, super-fine and super-pure products, and is an important equipment for crushing single crystal particles. In this process, the dust collection material with too small particle size is generated, and in the related technology, the treatment equipment for the ultra-fine particles of the dust collection material has low separation precision and separation efficiency.

[0037] Based on this, the air classifier 100 is simple in structure and has good separation precision and separation efficiency.

[0038] Reference will be made below Figures 1-5 The air classifier 100 according to the embodiments of the present application is described.

[0039] Please refer to Figure 1 and Figure 2 In some embodiments of the present application, the air classifier 100 comprises a casing 1 and a classification wheel 2, the casing 1 has a feed inlet 16 at the top, a first discharge outlet 13 at the bottom, and a second discharge outlet 14 at the side, and the classification wheel 2 is arranged in the casing 1 and comprises a rotating cage 21, the blades 20 of the rotating cage 21 comprise first blades 211 and second blades 212, the width of the first blades 211 is greater than that of the second blades 212, and the first blades 211 and the second blades 212 are arranged alternately in the circumferential direction of the rotating cage 21.

[0040] For particle separation, blades 20 of different widths can effectively handle particles of different sizes. The wide first blades 211 can produce a strong blocking and separating effect on larger particles. When the particle-containing airflow enters the rotating cage 21 of the classification wheel 2, the larger particles will be intercepted more easily when they hit the first blades 211 due to the wider blades providing a larger collision area, thereby guiding these large particles to move to the bottom of the casing 1 under the action of centrifugal force and be discharged from the first discharge outlet 13. The narrow second blades 212 are beneficial to handling smaller particles. Smaller particles can bypass the second blades 212 with the airflow, allowing small particles to continue to move in the rotating cage 21 under the carrying of the airflow, thereby achieving preliminary separation of large and small particles and giving smaller particles a chance to be discharged from the second discharge outlet 14 at the side.

[0041] From the perspective of the effect on the airflow, this staggered blade structure can make the airflow more uniform and stable. Wide blades and narrow blades alternate, which will not cause excessive blocking or sharp changes in the airflow in a certain local area. During the rotation of the rotating cage 21, the wide blades can cause strong disturbance to the airflow in the local area, which is beneficial to the separation of large particles, while the narrow blades cause relatively small disturbance to the airflow, allowing the airflow to quickly recover to a relatively stable state after passing through the narrow blade area, which helps small particles to be further screened in the stable airflow, thereby improving the accuracy and efficiency of classification.

[0042] The air classifier 100 according to the embodiments of the present application is simple in structure, can reduce the production cost of the equipment, the staggered blade structure can make the airflow more uniform and stable, and helps small particles to be further screened in the stable airflow, thereby improving the accuracy and efficiency of classification.

[0043] In some embodiments of the utility model, in the radial direction of the rotating cage 21, the distance H1 between the outer edge of the second blade 212 and the outer edge of the rotating cage 21 satisfies: 3mm≤H1≤7mm.

[0044] Exemplarily, H1 can be: 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm.

[0045] That is, the structure of the blade 20 of the rotating cage 21 can determine the flow field inside the air classifier 100, so that under the condition of ensuring the most suitable operating parameters of the classification equipment, the classification performance can be improved by reasonably improving the structural parameters of the blade 20 of the rotating cage 21. In the present application, when the distance is less than 3mm, the standard deviations of the radial and tangential velocities are larger than those when the distance is other distances, because when the air volume is constant, the velocity distribution of the outer edge of the rotating cage 21 is mainly affected by the resistance suffered by the airflow flowing through the blade 20 and the strength of the inertial back eddy between the blades 20, and the space volume of the blade 20 channel increases when the surface area of the blade 20 is too small, and the inertial eddy strength of the airflow between the blades 20 increases, and the velocity fluctuation is large. When the distance is greater than 7mm, backflow is prone to occur at the outlet of the airflow between the blades 20. It is easy to weaken the stability of the flow field; therefore, when the distance between the short blade and the outer edge of the rotating cage 21 is 3mm-7mm, preferably 4mm, the airflow velocity distribution on the outer edge of the rotating cage 21 is uniform, and the flow field between the blades 20 is stable.

[0046] In some embodiments of the utility model, referring to Figure 1 and Figure 2 , the shell 1 comprises a volute 11 and a conical funnel 12 connected to the lower end of the volute 11, the classification wheel 2 is located in the volute 11, and the first discharge port 13 is located at the bottom of the conical funnel 12. That is, the volute 11 provides a suitable space for the operation of the classification wheel 2, regulates the airflow direction, and helps the accurate separation of the material according to the particle size. The conical funnel 12 is ingeniously connected, and by virtue of its narrow lower part and wide upper part, it can effectively gather the separated coarse particles and make them smoothly flow to the bottom first discharge port 13, thereby avoiding accumulation and residue. The overall structure is compact and reasonable, which not only ensures smooth and efficient separation process, but also facilitates stable operation of the equipment and reduces maintenance cost.

[0047] In some embodiments of the utility model, referring to Figure 2 , the rotating axis of the rotating cage 21 extends along the horizontal direction, and the second discharge port 14 is located on the rotating axis.

[0048] Referring to Figure 2In the shown example, the dust collection material falls from the radial side of the rotating cage 21, that is, the upper side, to the rotating cage 21 area, under the suction of the centrifugal fan, the particles are subjected to the centripetal force of the airflow entering the rotating cage 21, the centrifugal force generated by the circular motion of the airflow in the annular area, and the gravity of the particles themselves, so that the coarse particles can better fall into the conical hopper 12 below. Since the rotating axis of the rotating cage 21 extends in the horizontal direction, the second discharge port 14 is located on the rotating axis, the fine particles can be discharged in a relatively short path and a relatively smooth manner, the risk of interference such as wall collision and turbulence can be reduced, the separation efficiency of the dust collection material can be improved, and the stability and accuracy of the equipment operation can be improved.

[0049] In some embodiments of the present application, in the axial direction, the length L1 of the first blade 211 and the length L2 of the second blade 212 satisfy: 0.78<=L2 / L1<=0.85.

[0050] That is, the relatively short second blade 212 cooperates with the relatively long first blade 211, and when guiding the airflow, the long first blade 211 can more fully comb and regularize the airflow direction, and the short second blade 212 can fine-tune the airflow speed and direction, which is beneficial to improve the screening effect of the dust collection material. The relatively short second blade 212 cooperates with the relatively long first blade 211 to reduce airflow sudden change, improve classification stability, and improve overall separation accuracy and efficiency.

[0051] In some embodiments of the present application, the rotating cage 21 further comprises a first annular plate 22 and a second annular plate 23, the first blade 211 is connected between the first annular plate 22 and the second annular plate 23, the second blade 212 comprises opposite free ends and fixed ends, and the fixed ends of the second blades 212 on both sides of the first blade 211 are respectively mounted on the first annular plate 22 and the second annular plate 23.

[0052] In combination with Figure 3 As shown, the second blades 212 connected to the first annular plate 22 are called upper blades, and the second blades 212 connected to the second annular plate 23 are called lower blades, and the plurality of upper blades and the plurality of lower blades are arranged alternately around the axis of the rotating cage 21. Thus, from the influence on the airflow, when the airflow carrying the particles flows into the rotating cage 21, the alternately arranged upper blades and lower blades can guide part of the airflow to change the flow direction, slow down the local flow speed, and promote the large-diameter particles to settle by inertia; and can further disrupt the original possible turbulence of the airflow, so that the airflow forms a plurality of "branches" with different strengths and orders and different directions, avoids the airflow carrying all the particles "all at once", and ensures that the small-diameter particles can continue the sorting journey in a relatively stable and controllable airflow environment.

[0053] At the level of particle classification efficiency, the upper blades and the lower blades are arranged at intervals, to create a clear classification "channel" for particles of different sizes. Large particles are blocked and diverted by the blades, and are collected at the bottom of the casing under the assistance of centrifugal force; small particles are precisely separated from the second side discharge port by the special airflow environment created by the blades, which can greatly reduce the mixing of coarse and fine particles, reduce misjudgment, and significantly improve the classification accuracy and overall efficiency.

[0054] In some embodiments of the present application, referring to Figure 4 and Figure 5 The number of the plurality of first blades 211 and the plurality of second blades 212 and N satisfy: 30≤N≤35.

[0055] Exemplarily, the number N can be 30, 31, 32, 33, 34, or 35.

[0056] In the above examples, the blades 20 that satisfy the above conditions can finely "cut" and comb the airflow when the device is running, forming a uniform, stable and orderly flow field, avoiding local turbulent or turbulent airflow, and improving the separation effect of coarse and fine particles following the predetermined trajectory.

[0057] In some embodiments of the present application, referring to Figure 5 The outer edge of the blade 20 of the rotating cage 21 is provided with a disturbance rod 24, which extends in the radial direction of the rotating cage 21, that is, the disturbance rod 24 extending in the radial direction continuously cuts and disturbs the airflow around the rotating cage 21, like putting a fast stirring paddle in a smooth water flow, greatly strengthening the turbulence intensity around the rotating cage. High-intensity turbulence causes material particles to break free from their original relatively stable state, and materials that may have been agglomerated or unevenly layered are fully dispersed, significantly increasing the dispersion of the rotating cage, and coarse and fine particles can be more thoroughly separated.

[0058] Exemplarily, the crushing device 200 can be an airflow mill, a mechanical mill or a colloidal mill.

[0059] Exemplarily, the separator 300 can be a cyclone separator 300.

[0060] Exemplarily, the disturbance rod 24 can be provided with a plurality of disturbance rods 24, which are arranged at intervals in the circumferential direction of the rotating cage 21.

[0061] In some embodiments of the present application, referring to Figure 2The side of the shell 1 is further provided with a first air inlet 15, which is located between the classification wheel 2 and the first discharge port 13 in the up-down direction. That is, in the process of the coarse powder particles falling downward towards the first discharge port 13, the airflow entering from the first air inlet 15 can concentrate the washing of the coarse powder particles to further remove the remaining superfine particles, thereby further improving the classification effect of the coarse powder particles.

[0062] In some embodiments of the present application, with reference to Figure 2 In the horizontal direction, the classification wheel 2 and the second discharge port 14 are oppositely arranged. Thus, when the material is screened by the airflow, the fine particles directly move towards the second discharge port 14 under the entrainment of the airflow, and the horizontally opposite design shortens the conveying path of the fine particles, reduces the risk of material deposition or secondary mixing due to airflow turbulence, wall collision and other factors. In this way, it can not only guarantee the separation accuracy and efficiently and accurately discharge the fine particles, but also help maintain stable operation of the equipment and continuously output high-quality separation effect.

[0063] In some embodiments of the present application, with reference to Figure 5 The blade 20 of the rotating cage 21 is an arc-shaped blade, and the axis of the arc-shaped blade is parallel to the rotation axis of the rotating cage 21. That is, the blade 20 of the rotating cage 21 is an arc-shaped blade, which can improve the stability of the airflow flow field, and the arc-shaped design conforms to the airflow direction, which can eliminate the turbulence "dead angle" caused by the right angle and the corner, so that the airflow can smoothly shuttle between the blades 20, which is beneficial to improve the separation effect of the dust collection material. In addition, compared with the outlet backflow easily caused by the traditional rectangular blade 20, the arc-shaped blade can guide the airflow to be smoothly discharged, reduce the backflow interference, make the dust collection material bear more uniform and accurate force, and improve the separation precision and separation efficiency of the dust collection material.

[0064] In some embodiments of the present application, with reference to Figure 4 and Figure 5 The blade 20 of the rotating cage 21 includes a first blade 211 and a second blade 212, the length of the first blade 211 is greater than that of the second blade 212, and a plurality of first blades 211 and a plurality of second blades 212 are arranged in a staggered manner in the circumferential direction of the rotating cage 21.

[0065] That is, the installation form of the blades 20 of the rotor cage 21 is staggered installation of long blades and short blades. The equal-length-blade rotor cage 21 is improved into the staggered installation of long blades and short blades, which can effectively improve the distribution of the tangential and radial velocities on the outer cylindrical surface of the rotor cage 21, and is beneficial to improve the classification accuracy and reduce the classification particle size. Compared with the equal-length-blade, the staggered-blade 20 form reduces the radial velocity and increases the tangential velocity of the air flow at the inlet of the rotor cage 21, which is caused by the increase of the cross-sectional area at the air flow inlet of the improved rotor cage 21 under the same air volume and rotational speed. Under the same conditions, the tangential and radial velocity distributions of the air flow in the vortex air classifier 100 of the staggered-blade 20 arranged rotor cage 21 are uniform, and the velocity fluctuation is small, so that the fine powder particles with narrow particle size distribution range can be obtained.

[0066] The utility model discloses still propose a kind of classification separation system 10000 of air classifier 100 with above-mentioned embodiment.

[0067] With reference to Figure 2 According to the classification separation system 10000 of the utility model embodiment, the first-stage classification crushing device 1000 includes a crushing device 200 and a separator 300, the crushing device 200 is used for crushing materials, the separator 300 is communicated with the crushing device 200, the separator 300 is used for collecting the crushed materials, and is used for separating the materials into qualified materials meeting a first condition and first dust collection materials meeting a second condition, the qualified materials are conveyed from a first material outlet, and the first dust collection materials are conveyed towards a second material outlet, wherein the particle size of the qualified materials is larger than that of the first dust collection materials; the second-stage classification separation device 2000 includes at least one air classifier 100, wherein when the air classifier 100 is multiple, the inlet 16 of one of the adjacent two air classifiers 100 is communicated with the second material outlet, and the second material outlet 14 is communicated with the inlet 16 of the other air classifier 100.

[0068] Illustratively, the materials first enter the crushing device 200 of the first-stage classification crushing device 1000, where the materials are subjected to crushing treatment, and as the crushing operation continues, fine powder materials meeting the condition in particle size enter the inside of the separator 300, and coarse powder materials not meeting the particle size requirement continue to enter the crushing device 200 for crushing, and the separator 300 separates the fine powder materials according to the pre-set condition, to obtain qualified materials discharged from the bottom (i.e. the first material outlet) and dust collection materials discharged from the exhaust port (i.e. the second material outlet). Specifically, the qualified materials with relatively large particle size meeting the first condition are accurately conveyed out from the first material outlet under the action of the separator 300, and enter the subsequent corresponding processing process or temporary storage area; and the first dust collection materials with small particle size meeting the second condition are guided to the second material outlet, to open the next step of fine classification.

[0069] The first dust collection material output from the second material outlet of the first stage classification crushing device 1000 is then transported to the second stage classification separation device 2000. If the second stage classification separation device 2000 is equipped with only one air classifier 100, the second dust collection material directly enters the feed inlet of the air classifier 100, and in the air classifier 100, by means of the key working mechanism of high-speed rotating airflow, the second dust collection material is again subjected to fine classification screening according to the physical properties such as particle size and density of the material, so that different specifications of materials are effectively separated, and each is output from the corresponding outlet, so as to achieve more accurate classification effect and meet the diversified production and processing needs.

[0070] If the second stage classification separation device 2000 contains multiple air classifiers 100, at this time, the second dust collection material first enters the feed inlet of the first air classifier 100, and after the initial fine screening, part of the material is output from the outlet of the air classifier 100, and the other part of the material is transported to the feed inlet of the adjacent next air classifier 100, and the fine classification process is repeated. In this way, the material is orderly transferred and screened between multiple air classifiers 100 in sequence until the ideal classification state is achieved, and the material is classified according to the required precision standard, so as to be efficiently utilized in subsequent corresponding links such as chemical synthesis, material preparation, product processing, etc.

[0071] The classification separation system 10000 according to the embodiment of the utility model can make the material orderly transfer and screen between multiple air classifiers 100 in sequence until the ideal classification state is achieved, and the material is classified according to the required precision standard, so as to be efficiently utilized in subsequent corresponding links such as chemical synthesis, material preparation, product processing, etc.

[0072] Taking the multi-stage separation of the dust collection material of lithium ion positive electrode material as an example, first, the lithium ion positive electrode material is sent to the crushing device 200 of the first stage classification crushing device 1000, the fine powder material meeting the particle size condition enters the inside of the separator 300, and the particle size of the qualified material meeting the first condition is 3.0 μm~4.0 μm, which is discharged from the bottom of the separator 300 (i.e. the first material outlet); the first dust collection material meeting the second condition has a particle size less than 3.0 μm, which enters the second stage classification separation device 2000 from the second material outlet of the separator 300.

[0073] Exemplarily, the second-stage classification separation device 2000 comprises two air classifiers 100, the first air classifier 100 can separate the first dust collection material into a second dust collection material and a third dust collection material, and the second air classifier 100 can separate the third dust collection material into a fourth dust collection material and a fifth dust collection material, the particle size D3 of the second dust collection material satisfies: 1.5 μm≤D3<3.0 μm; the particle size D5 of the fourth dust collection material satisfies: 0.9 μm≤D5<1.5 μm; and the particle size D6 of the fifth dust collection material satisfies: D6<0.9 μm.

[0074] In actual application, the second dust collection material can be directly mixed with the finished product of qualified material to obtain a first mixed material; the fourth dust collection material is mixed at a mixing process and then sintered to realize single crystal particle regrowth, thereby obtaining a second mixed material; and the fifth dust collection material is degraded to realize efficient utilization of the dust collection material after classification separation.

[0075] Specifically, the mixing ratio of the second dust collection material is 30%-50% based on the weight of the first mixed material; preferably, the mixing frequency of the screw belt is 40 Hz-50 Hz, and the mixing time is 3 h.

[0076] The fourth dust collection material is mixed with materials of a production line at a mixing process to obtain a mixed material, wherein the materials of the production line at least comprise: a positive electrode material precursor, a lithium source and a doping element M, the mixing ratio of the doping element M is greater than or equal to 0, and the mixing ratio of the fourth dust collection material is 1 wt%-5 wt% based on the weight of the second mixed material; the obtained mixed material is sintered under a process atmosphere; the sintered material is sequentially subjected to coarse crushing, fine crushing and sieving to obtain the second mixed material containing the positive electrode material pulverized dust collection material mixed with the fourth dust collection material. The sintering temperature is 800℃-1000℃, and the time is 20 h-30 h; and / or, the oxygen content of the process atmosphere is ≥90 vol%, and the gas flow is 600-1300 Nm 3 / h; and / or, the mixing ratio of the fourth dust collection material is 4.1 wt%-5 wt%.

[0077] The fifth dust collection material is collected by a dust collector 400, which can be a sintering plate.

[0078] Exemplarily, the fifth dust collection material can be directly degraded.

[0079] The positive electrode material obtained by the above method can have the following composition:

[0080] A positive electrode material, the positive electrode material comprising a compound represented by the following molecular formula: LiNi x Co y Mn z M aO2, wherein, 0 < x < 1, 0 < y < 1, 0 < z < 1, 0 ≤ a < 0.5, the positive electrode material comprises: 50wt%-70wt% of the finished product prepared by post-treatment of the qualified material separated by the classification separation system, and 30wt%-50wt% of the first mixed material; or, the positive electrode material comprises: at least 95wt% of the finished product prepared by post-treatment of the qualified material separated by the classification separation system, or further comprises 1wt%-5wt% of the second mixed material. The method is particularly suitable for the single-crystal multi-element positive electrode material with Ni content greater than or equal to 60% in terms of the mole percentage of transition metals, which is separated by the classification separation system.

[0081] Other configurations and operations of the air classifier 100 and the classification separation system 10000 according to the embodiments of the present application are known to those skilled in the art, and will not be described in detail herein.

[0082] In the description of the present application, the description of the terms "some embodiments", "optionally", "further", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0083] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. An air classifier (100) characterized by, The utility model relates to a kind of classification wheel and classification wheel machine, including: Shell (1), the top of the shell (1) has feed inlet, the bottom of the shell (1) has first discharge port (13), the side of the shell (1) is provided with second discharge port (14), Classification wheel (2), the classification wheel (2) is arranged in the shell (1), the classification wheel (2) includes rotating cage (21), the blade (20) of the rotating cage (21) includes first blade (211) and second blade (212), the width of the first blade (211) is greater than the width of the second blade (212), in the circumferential direction of the rotating cage (21), multiple first blades (211) and multiple second blades (212) are staggered.

2. The air classifier (100) of claim 1, characterized in that, In the radial direction of the rotating cage (21), the distance H1 between the outer edge of the second blade (212) and the outer edge of the rotating cage (21) satisfies: 3mm≤H1≤7mm.

3. The air classifier (100) of claim 1, wherein, The shell (1) includes volute (11) and conical funnel (12) connected at the lower end of volute (11), the classification wheel (2) is located in the volute (11), and the first discharge port (13) is located at the bottom of the conical funnel (12).

4. The air classifier (100) of claim 1, wherein, The rotating axis of the rotating cage (21) extends in the horizontal direction, and the second discharge port (14) is located on the rotating axis.

5. The air classifier (100) of claim 1, wherein, The blade (20) of the rotating cage (21) is an arc-shaped blade, and the axis of the arc-shaped blade is parallel to the rotating axis of the rotating cage (21).

6. The air classifier (100) of claim 1, wherein, In the axial direction, the length L1 of the first blade (211) and the length L2 of the second blade (212) satisfy: 0.78≤L2 / L1≤0.

85.

7. The air classifier (100) of claim 1, wherein, The rotating cage (21) further includes a first annular plate (22) and a second annular plate (23), the first blade (211) is connected between the first annular plate (22) and the second annular plate (23), the second blade (212) includes opposite free ends and fixed ends, and the fixed ends of the second blades (212) on both sides of the first blade (211) are respectively mounted on the first annular plate (22) and the second annular plate (23).

8. The air classifier (100) of claim 1, wherein, The sum N of the number of multiple first blades (211) and multiple second blades (212) satisfies: 30≤N≤35.

9. The air classifier (100) of claim 1, wherein, The outer edge of the blade (20) of the rotating cage (21) is provided with a disturbance rod (24), and the disturbance rod (24) extends in the radial direction of the rotating cage (21).

10. The air classifier (100) of claim 1, wherein, The side of the shell (1) is further provided with a first air inlet (15), and in the up-down direction, the first air inlet (15) is located between the classification wheel (2) and the first discharge port (13).

11. A fractionation system (10000) characterized by, The utility model relates to a kind of classification wheel and classification wheel machine, including: The first stage classified crushing device (1000) comprises a crushing device (200) for crushing materials and a separator (300) in communication with the crushing device (200), the separator (300) is used for collecting the crushed materials and separating the materials into qualified materials meeting a first condition and first dust collection materials meeting a second condition, the qualified materials are conveyed from a first material outlet, and the first dust collection materials are conveyed towards a second material outlet, wherein the particle size of the qualified materials is larger than that of the first dust collection materials. The second stage classified separation device (2000) comprises at least one air classifier (100) according to any one of claims 1-10, wherein when the air classifier (100) is multiple, the feeding port of one of the adjacent two air classifiers (100) is in communication with the second material outlet, and the second material outlet (14) is in communication with the feeding port of the other air classifier (100).

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