Middling ore continuous crushing and screening system and crushing and screening method based on lithium ore

Abstract

The invention provides a middling continuous crushing and screening system and method.The system comprises a first cone crusher (18), a second cone crusher (19), a plurality of vertical shaft impact crushers (20-22) and a plurality of three-stage screening machines (28-30), and the first cone crusher (18), the second cone crusher (19), the vertical shaft impact crushers (20-22) and the three-stage screening machines (28-30) can cooperate to conduct cyclic crushing and screening on the lithium ore till the particle size of lithium ore particles meets the requirement; when the system is used, the lithium ore is subjected to graded circulating screening and circulating crushing, the treatment speed of the lithium ore is increased, and the system can be suitable for efficient treatment of large-scale lithium ore.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ore middling screening, and in particular to a lithium ore middling continuous screening system and screening method. Background Art

[0002] With the development of modern society, the importance of lithium ore has become increasingly prominent. At present, the application fields of lithium ore are very wide, mainly including the following aspects: lithium battery, lithium ore is one of the core raw materials for lithium battery manufacturing. Lithium batteries are widely used in portable electronic devices, electric vehicles, energy storage systems and other fields due to their high energy density, long life and environmental protection characteristics; energy storage system, lithium ore is used in energy storage system, which can provide efficient and reliable energy storage solutions to meet the needs of different scenarios, such as energy storage of solar and wind power generation; electric vehicles, electric vehicles are another important field of lithium ore application. Lithium-ion batteries, as the main power source of electric vehicles, have promoted the development of the electric vehicle industry; consumer electronics, lithium ore is also used in various consumer electronics products, such as smart phones, tablets, laptops, etc. These products require high-performance batteries to support their long-term operation; chemical and pharmaceutical, metallic lithium also has important applications in the chemical and pharmaceutical fields, and is used to manufacture various chemicals and drugs; metallurgy and electronics industry, lithium is also widely used in metallurgy and electronics industry, and is used to manufacture lightweight alloys and other metals.

[0003] Therefore, the development and efficiency of lithium ore will have a crucial impact on its application. In the past, the crushing and screening of lithium ore were often separated. In terms of process, the two were upstream and downstream. The treatment of lithium ore was relatively extensive, resulting in the need for frequent adjustments to the screening and crushing process, which affected the efficiency and quality of the final product. Inappropriate particle size also affected the efficiency of crushing and screening, thereby reducing the development and utilization efficiency of lithium ore. Summary of the invention

[0004] In view of this, the present invention proposes, on one hand, a lithium ore continuous crushing and screening system, comprising a first cone crusher (18), a second cone crusher (19), a plurality of vertical shaft impact crushers (20-22) and a plurality of three-stage screening machines (28-30); the first cone crusher (18) is matched with the plurality of three-stage screening machines (28-30) through a second belt conveyor (23); the lithium ore is first crushed by the first cone crusher (18), and then conveyed to the three-stage screening machines (28-30) through the second belt conveyor (23) for screening. Screening, the screened primary particles of lithium ore are collected for later use, the secondary particles of lithium ore are conveyed to the plurality of vertical shaft impact crushers (20-22) through a matching secondary particle return crushing conveyor (32) for further crushing, the tertiary particles of lithium ore are conveyed to the second cone crusher (19) through a matching tertiary particle return crushing conveyor (31) for further crushing, and after the secondary and tertiary particles of lithium ore are crushed, they are further conveyed to the plurality of tertiary screening machines (28-30) through the second belt conveyor (23) for screening until the particle size reaches the requirements of the primary particle size of lithium ore.

[0005] Preferably, the vertical shaft impact crushers include three, namely a No. 1 vertical shaft impact crusher (20), a No. 2 vertical shaft impact crusher (21) and a No. 3 vertical shaft impact crusher (22).

[0006] Preferably, the three-stage screening machine includes three screening machines, namely screening machine No. 1 (28), screening machine No. 2 (29), and screening machine No. 3 (30).

[0007] Furthermore, the first cone crusher (18) is provided with a coarse ore bin (1) and a pre-crushing buffer bin (2) respectively, and a first belt conveyor (11) is provided between the coarse ore bin (1) and the pre-crushing buffer bin (2) respectively. The lithium ore raw material is stored in the coarse ore bin (1) and is discharged to the first belt conveyor (11) through a matching vibrating feeder (10), and then fed to the pre-crushing buffer bin (2), and further discharged to the first cone crusher (18).

[0008] Furthermore, the first belt conveyor (11) is provided with a first iron remover (36) corresponding to the first belt conveyor (11), which can remove iron from the lithium ore passing through the first belt conveyor (11).

[0009] Preferably, the first belt conveyor (11) is also provided with corresponding rollers (12).

[0010] Furthermore, the second cone crusher (19), the vertical shaft impact crusher (20-22) and the three-stage screening machine (28-30) are respectively provided with a three-stage particle buffer bin (3), a two-stage particle buffer bin (4-6) and a post-crushing particle buffer bin (7-9); The tertiary particles of lithium ore are buffered in the tertiary particle buffer bin (3) and then enter the second cone crusher (19) for crushing. The secondary particles are buffered in the secondary particle buffer bin (4-6) and then enter the vertical shaft impact crusher (20-22) for crushing. Before entering the tertiary screening machine (28-30) for screening, the lithium ore particles first enter the post-crushing particle buffer bin (7-9) for buffering.

[0011] Preferably, there are three secondary particle buffer bins, namely, secondary particle buffer bin No. 1 (4), secondary particle buffer bin No. 2 (5) and secondary particle buffer bin No. 3 (6).

[0012] Preferably, the crushed particle buffer bins include three, namely, a No. 1 crushed particle buffer bin (7), a No. 2 crushed particle buffer bin (8), and a No. 3 crushed particle buffer bin (9). Furthermore, the first cone crusher (18), the second cone crusher (19), the plurality of vertical shaft impact crushers (20-22) and the plurality of three-stage screening machines (28-30) are respectively provided with a first cone crushing front conveyor (13), a second cone crushing front conveyor (14), a vertical shaft impact front crushing front conveyor (15-17) and a pre-screening belt conveyor (25-27), and the lithium ore materials received by each of the machines are transported to the destination through the other corresponding conveyors.

[0013] Preferably, the vertical shaft pre-impact and pre-crushing conveyors include three, namely, a No. 1 vertical shaft pre-impact and pre-crushing conveyor (15), a No. 2 vertical shaft pre-impact and pre-crushing conveyor (16), and a No. 3 vertical shaft pre-impact and pre-crushing conveyor (17).

[0014] Preferably, the pre-screening belt conveyors include three, namely, pre-screening belt conveyor No. 1 (25), pre-screening belt conveyor No. 2 (26) and pre-screening belt conveyor No. 3 (27).

[0015] Furthermore, the secondary particle return crushing conveyor (32) is provided with a second iron remover (37) and the tertiary particle return crushing conveyor (31) is provided with a third iron remover (38). The second iron remover (37) and the third iron remover (38) respectively remove iron from the materials on their corresponding conveyors.

[0016] Furthermore, a plurality of the screening machines (28-30) are provided with a corresponding belt conveyor (34) for conveying the first-stage particles after screening, which is capable of conveying the first-stage particles after screening by the screening machines and conveying them to the next process.

[0017] Furthermore, the second belt conveyor (23) and the secondary particle return crushing conveyor (32) are respectively provided with a second belt conveyor trolley (24) and a secondary particle return crushing conveyor trolley (33).

[0018] Specifically, the continuous crushing and screening system for middlings based on lithium ore sets the crushing and screening into a closed-loop, continuous, cyclic system, which not only improves the crushing and screening efficiency, but also improves the crushing and screening efficiency by setting up multiple secondary crushers and multiple tertiary screening machines. The particle size of the processed lithium ore meets the production requirements, which improves the efficiency and quality of lithium ore processing overall.

[0019] Another aspect of the present invention further discloses a screening method for a lithium ore continuous screening system, comprising: The lithium ore is crushed for the first time. After the material is crushed for the first time, it enters the three-stage screening machine for three-stage screening. The first-level particles obtained enter the next process, and the second-level particles and third-level particles obtained return to the crushing process; After the secondary crushing of lithium ore, the secondary and tertiary particles are crushed at the corresponding level, and then enter the tertiary screening machine for tertiary screening. The particles after the second screening continue to be crushed and screened in a cycle until their particle size meets the requirements of the primary particles; The new lithium ore is crushed. While the previous lithium ore is being crushed in a cycle, the new lithium ore also begins to undergo primary and secondary crushing and enters a crushing cycle until the particle size meets the requirements of the primary particles.

[0020] Furthermore, the lithium ore is subjected to iron removal treatment before each crushing.

[0021] The present invention provides a screening method based on a lithium ore continuous screening system, which improves the processing speed of lithium ore by performing graded cyclic screening and cyclic crushing on lithium ore, and can be suitable for efficient processing of large-scale lithium ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of the structure of a continuous screening system for middling ore based on lithium ore provided in an embodiment of the present invention; Figure 2 A flow chart of a screening method for a continuous screening system for middling ore based on lithium ore provided in an embodiment of the present invention; In the figure, 1, coarse ore bin; 2, buffer bin before crushing; 3, three-stage particle buffer bin; 4, No. 1 secondary particle buffer bin; 5, No. 2 secondary particle buffer bin; 6, No. 3 secondary particle buffer bin; 7, No. 1 post-crushing particle buffer bin; 8, No. 2 post-crushing particle buffer bin; 9, No. 3 post-crushing particle buffer bin; 10, vibrating feeder; 11, first belt conveyor; 12, roller; 13, first cone crusher front conveyor; 14, second cone crusher front conveyor; 15, No. 1 vertical shaft impact crusher front conveyor; 16, No. 2 vertical shaft impact crusher front conveyor; 17, No. 3 vertical shaft impact crusher front conveyor; 18, first cone crusher; 19, second cone crusher ; 20, No. 1 vertical shaft impact crusher; 21, No. 2 vertical shaft impact crusher; 22, No. 3 vertical shaft impact crusher; 23, the second belt conveyor; 24, the second belt conveyor mobile trolley; 25, No. 1 pre-screening belt conveyor; 26, No. 2 pre-screening belt conveyor; 27, No. 3 pre-screening belt conveyor; 28, No. 1 screening machine; 29, No. 2 screening machine; 30, No. 3 screening machine; 31, tertiary particle return crushing conveyor; 32, secondary particle return crushing conveyor; 33, secondary return crushing conveyor mobile trolley; 34, primary particle conveying belt conveyor; 35, medium ore conveying belt conveyor; 36, the first iron remover; 37, the second iron remover; 38, the third iron remover. DETAILED DESCRIPTION

[0023] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] It should be noted that the primary particles of lithium ore mentioned in the present invention refer to lithium ore with a particle size of less than 0.5 mm; the secondary particles refer to lithium ore with a particle size of 0.5 ≤ lithium ore ≤ 1.7 mm; and the tertiary particles refer to lithium ore with a particle size of more than 1.7 mm.

[0025] See also Figure 1As shown, it is a lithium ore continuous crushing and screening system based on the embodiment of the present invention, comprising a first cone crusher (18), a second cone crusher (19), a plurality of vertical shaft impact crushers (20-22) and a plurality of three-stage screening machines (28-30); the first cone crusher (18) is matched with the three-stage screening machine through a second belt conveyor (23); the lithium ore is first crushed by the first cone crusher (18), and then conveyed to the plurality of three-stage screening machines (28-30) through the second belt conveyor (23) for screening; the screened lithium ore The primary particles are collected for standby use and transferred to the next process. The secondary particles of lithium ore are conveyed to the vertical shaft impact crusher (20-22) through the secondary particle return crushing conveyor (32) provided in conjunction with the secondary particle return crushing conveyor for further crushing. The tertiary particles of lithium ore are conveyed to the second cone crusher (19) through the tertiary particle return crushing conveyor (31) provided in conjunction with the secondary particle return crushing conveyor for further crushing. After the secondary and tertiary particles of lithium ore are crushed, they are further conveyed to the tertiary screening machine (28-30) through the second belt conveyor (23) for screening until the particle size reaches the size requirement of the primary particles of lithium ore and then enter the next process.

[0026] Specifically, by setting up multiple crushers and three-stage screening machines, the crushing and screening efficiency can be greatly improved to meet the needs of large-scale production. The cone crusher is selected, which has efficient and uniform crushing capacity and adaptability to different materials. The preliminary treatment of lithium ore materials and the treatment of the third-level largest particles can better improve the crushing efficiency. The vertical shaft impact crusher is selected to crush the secondary particles because it has the characteristics of excellent finished product particle shape. At the same time, the fineness adjustment is flexible, and different particle size requirements can be met by adjusting the equipment parameters.

[0027] In this embodiment, the vertical shaft impact crushers include three, namely, a No. 1 vertical shaft impact crusher (20), a No. 2 vertical shaft impact crusher (21), and a No. 3 vertical shaft impact crusher (22). Preferably, the three-stage screening machine includes three screening machines, namely screening machine No. 1 (28), screening machine No. 2 (29), and screening machine No. 3 (30).

[0028] In this embodiment, the first cone crusher (18) is provided with a coarse ore bin (1) and a pre-crushing buffer bin (2), and a first belt conveyor (11) is provided between the coarse ore bin (1) and the pre-crushing buffer bin (2). The lithium ore raw material is stored in the coarse ore bin (1) and is discharged to the first belt conveyor (11) through a matching vibrating feeder (10), and then fed to the pre-crushing buffer bin (2), and further discharged to the first cone crusher (18).

[0029] The first belt conveyor (11) is provided with a first iron remover (36) corresponding to the first belt conveyor (11), which can remove iron from the lithium ore passing through the first belt conveyor (11).

[0030] Reference Figure 1 As shown in , the first belt conveyor (11) is also provided with corresponding rollers (12).

[0031] Continue to refer to Figure 1 As shown in the figure, the second cone crusher (19), the vertical shaft impact crusher (20-22) and the three-stage screening machine (28-30) are respectively provided with a three-stage particle buffer bin (3), a two-stage particle buffer bin (4-6) and a post-crushing particle buffer bin (7-9); The tertiary particles of lithium ore are buffered in the tertiary particle buffer bin (3) and then enter the second cone crusher (19) for crushing. The secondary particles are buffered in the secondary particle buffer bin (4-6) and then enter the vertical shaft impact crusher (20-22) for crushing. Before entering the tertiary screening machine (28-30) for screening, the lithium ore particles first enter the post-crushing particle buffer bin (7-9) for buffering.

[0032] The secondary particle buffer bins are provided with three, namely, secondary particle buffer bin No. 1 (4), secondary particle buffer bin No. 2 (5) and secondary particle buffer bin No. 3 (6).

[0033] The crushed particle buffer bins include three, namely, a No. 1 crushed particle buffer bin (7), a No. 2 crushed particle buffer bin (8), and a No. 3 crushed particle buffer bin (9). Specifically, by setting up multiple buffer bins, the buffer bins can adjust the material flow and ensure the stable operation of the crusher. In the ore crushing process, there is often a mismatch between the ore supply speed and the crusher's processing capacity. The use of buffer bins can temporarily store excess ore to avoid crusher shutdown or overload due to insufficient or excessive material supply. The buffer bin stores a certain amount of material to meet subsequent production needs, and the equipment in front of the buffer bin can also be shut down for maintenance. This can not only improve production efficiency, but also extend the service life of the equipment.

[0034] Secondly, the buffer bin can balance production and reduce production fluctuations. During the ore crushing process, the supply of ore may change due to various reasons, resulting in production fluctuations. The buffer bin can serve as an intermediate link to temporarily store and adjust materials, thereby reducing fluctuations in the production process and ensuring the continuity and stability of production.

[0035] Reference Figure 1As shown in the figure, the first cone crusher (18), the second cone crusher (19), the plurality of vertical shaft impact crushers (20-22) and the plurality of three-stage screening machines (28-30) are respectively provided with a first cone crushing front conveyor (13), a second cone crushing front conveyor (14), a vertical shaft impact front crushing front conveyor (15-17) and a pre-screening belt conveyor (25-27), and the lithium ore materials received by each of the machines are transported to the destination through the other corresponding conveyors.

[0036] In this embodiment, the vertical shaft pre-impact and pre-crushing conveyors include three, namely, a No. 1 vertical shaft pre-impact and pre-crushing conveyor (15), a No. 2 vertical shaft pre-impact and pre-crushing conveyor (16), and a No. 3 vertical shaft pre-impact and pre-crushing conveyor (17).

[0037] In this embodiment, the pre-screening belt conveyors include three, namely, a No. 1 pre-screening belt conveyor (25), a No. 2 pre-screening belt conveyor (26), and a No. 3 pre-screening belt conveyor (27).

[0038] Continue to refer to Figure 1 As shown in the figure, the secondary particle return crushing conveyor (32) is provided with a second iron remover (37) and the tertiary particle return crushing conveyor (31) is provided with a third iron remover (38). The second iron remover (37) and the third iron remover (38) respectively remove iron from the materials on their corresponding conveyors.

[0039] In this embodiment, a plurality of the screening machines (28-30) are provided with a corresponding belt conveyor (34) for conveying the first-level particles after screening, which can convey the first-level particles after screening by the screening machines and convey them to the next process.

[0040] In this embodiment, the second belt conveyor (23) and the secondary particle return crushing conveyor (32) are respectively provided with a second belt conveyor trolley (24) and a secondary particle return crushing conveyor trolley (33).

[0041] Specifically, the lithium ore-based continuous crushing and screening system sets the crushing and screening into a closed-loop, continuous, cyclic system, which can not only improve the crushing and screening efficiency, but also improve the crushing and screening efficiency by setting up multiple secondary crushers and multiple tertiary screening machines. The particle size of the processed lithium ore meets the production requirements, which generally improves the efficiency of lithium ore processing and the screening speed. The continuous screening system for middlings based on lithium ore disclosed in the embodiment of the present invention can be applied in climatic environments such as low air pressure, low oxygen content, and large temperature difference between day and night in terms of equipment selection, because: The rotating parts of the machine, such as the motor, use a customized plateau motor; the grease of the bearing, etc., adopts a small amount of grease filling and a high frequency to adapt to the large temperature difference in the environment and avoid the grease from solidifying easily after shutdown; In terms of electricity, if SF 6 The cabinet (with superior high-voltage arc-extinguishing performance) is of the inflatable type. Unlike the inflatable on the plains, it requires low pressure. The standard inflatable on the plains is prone to bulging and bursting on the plateau, so electrical appliances that can adapt to low pressure are used.

[0042] The embodiment of the present invention also discloses a screening method based on a lithium ore continuous screening system, see the attached Figure 2 ,include: S01, the lithium ore is crushed for the first time. After the material is crushed for the first time, it enters the three-stage screening machine for three-stage screening. The first-level particles obtained enter the next process, and the second-level particles and the third-level particles obtained return to the crushing process; S02, the lithium ore is crushed twice, and the obtained secondary particles and tertiary particles are crushed at the corresponding levels, and then enter the three-stage screening machine for three-stage screening. The particles after the second screening continue to be crushed and screened in a cycle until their particle size meets the requirements of the first-stage particles; S03, new lithium ore crushing. While the previous lithium ore is being crushed in a cycle, the new lithium ore also begins to undergo primary and secondary crushing, entering a crushing cycle until the particle size meets the requirements for primary particles.

[0043] In this embodiment, the lithium ore is subjected to iron removal treatment before each crushing.

[0044] A preferred embodiment of a screening method for a continuous screening system for middling ore based on lithium ore disclosed in an embodiment of the present invention, combined with the continuous screening system for middling ore based on lithium ore of the present application, is as follows: Step (1), storing lithium ore in a coarse ore bin (1); Step (2), the lithium ore is fed to the first belt conveyor (11) through the vibrating feeder (10); Step (3), the lithium ore is conveyed to the pre-crushing buffer bin (2) via a first belt conveyor (11); Step (4), during the process of conveying the lithium ore by the first belt conveyor (11), the iron-containing and other metal substances mixed therein are removed by the first iron remover (36) correspondingly arranged on the first belt conveyor (11); Step (5), the lithium ore is discharged from the pre-crushing buffer bin (2) and transported to the first cone crusher (18) through the pre-first cone crushing conveyor (13); Step (6), after the lithium ore is crushed by the first cone crusher (18), it falls to the crushed second belt conveyor (23) and is transported to the screening workshop; Step (7), the second belt conveyor (23) uses the second belt conveyor moving trolley (24) to evenly distribute the crushed lithium ore in the crushed particle buffer bins of the screening workshop, that is, the No. 1 crushed particle buffer bin (7), the No. 2 crushed particle buffer bin (8), and the No. 3 crushed particle buffer bin (9); Step (8), the lithium ore in the buffer bin of the screening workshop falls into the No. 1 screening front belt conveyor (25) and is transported to the No. 1 screening machine (28); Step (9), No. 1 screening machine (28) undergoes three-stage separation, the first-stage separation screens the lithium ore middlings and drops them to the post-screening first-stage particle conveyor belt (34), then transfers them to the middling particle conveyor belt (35), and is sent to the next process; the second-stage separation returns the secondary particles to the secondary particle return crushing conveyor (32), and then returns them to the vertical shaft impact crushing buffer bin, namely, No. 1 secondary particle buffer bin (4), No. 2 secondary particle buffer bin (5), and No. 3 secondary particle buffer bin (6); the third-stage separation returns the third-stage particles to the third-stage particle return crushing conveyor (31) and is transported to the third-stage particle buffer bin (3); Step (10), the three-level particle buffer bin (3) continues to drop material through the second cone crusher (19), and the crushed lithium ore falls to the second belt conveyor (23), and is transported to the screening workshop for three-level screening again; Step (11), the three secondary particle buffer bins (4 / 5 / 6) continue to drop materials to the corresponding three vertical shaft impact crushers (20 / 21 / 22) for impact crushing. After crushing, the lithium ore falls to the second belt conveyor (23) and is transported to the screening workshop for screening and three-level separation again; Step (12), by repeating the crushing method of steps (9) to (11) in an infinite cycle, the lithium ore is sieved into medium ore particles suitable for medium ore, that is, the primary particles mentioned in this application; Step (13), while repeating steps (9)-(11), the lithium ore in the coarse ore bin (1) continues to be fed to the first belt conveyor (11) through the vibrating feeder (10), and the crushing and screening steps (2)-(9) are repeated.

[0045] The present invention provides a screening method based on a lithium ore continuous screening system, which improves the processing speed of lithium ore by performing graded cyclic screening and cyclic crushing on lithium ore, and can be suitable for efficient processing of large-scale lithium ore.

[0046] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0047] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A continuous screening system for middlings based on lithium ore, characterized in that: The invention comprises a first cone crusher (18), a second cone crusher (19), a plurality of vertical shaft impact crushers and a plurality of three-stage screening machines; the first cone crusher (18) is matched with the three-stage screening machine through a second belt conveyor (23); the lithium ore is first crushed by the first cone crusher (18), and then conveyed to the three-stage screening machine through the second belt conveyor (23) for screening; the first-level particles of the lithium ore after screening are collected for standby use; the second-level particles of the lithium ore are conveyed to the vertical shaft impact crusher for further crushing through a matching second-level particle return crushing conveyor (32); the third-level particles of the lithium ore are conveyed to the second cone crusher (19) for further crushing through a matching third-level particle return crushing conveyor (31); after crushing, the second-level particles and the third-level particles of the lithium ore are further conveyed to the three-stage screening machine through the second belt conveyor (23) for screening until the particle size reaches the requirement of the first-level particle size of the lithium ore.

2. The continuous screening system for middlings based on lithium ore according to claim 1, characterized in that: The first cone crusher (18) is provided with a coarse ore bin (1) and a pre-crushing buffer bin (2) respectively, and a first belt conveyor (11) is provided between the coarse ore bin (1) and the pre-crushing buffer bin (2) respectively. The lithium ore raw material is stored in the coarse ore bin (1) and is discharged to the first belt conveyor (11) through a matching vibrating feeder (10), and then fed to the pre-crushing buffer bin (2), and further discharged to the first cone crusher (18).

3. The continuous screening system for middlings based on lithium ore according to claim 1, characterized in that: The first belt conveyor (11) is provided with a first iron remover (36) corresponding to the first belt conveyor (11), which can remove iron from the lithium ore passing through the first belt conveyor (11).

4. The continuous screening system for middlings based on lithium ore according to claim 1, characterized in that: The second cone crusher (19), the vertical shaft impact crusher and the three-stage screening machine are respectively provided with a three-stage particle buffer bin (3), a two-stage particle buffer bin and a post-crushing particle buffer bin; The tertiary lithium ore particles are buffered in the tertiary particle buffer bin (3) and then enter the second cone crusher (19) for crushing. The secondary particles are buffered in the secondary particle buffer bin and then enter the vertical shaft impact crusher for crushing. Before entering the tertiary screening machine for screening, the lithium ore particles first enter the crushed particle buffer bin for buffering.

5. The continuous screening system for middlings based on lithium ore according to claim 4, characterized in that: The first cone crusher (18), the second cone crusher (19), the plurality of vertical shaft impact crushers and the plurality of three-stage screening machines are respectively provided with a first cone crushing front conveyor (13), a second cone crushing front conveyor (14), a vertical shaft impact front crushing front conveyor and a front screening belt conveyor. The lithium ore materials received by each of the machines are transported to the destination via the other corresponding conveyors.

6. The continuous screening system for middlings based on lithium ore according to claim 5, characterized in that: The secondary particle return crushing conveyor (32) is provided with a second iron remover (37) and the tertiary particle return crushing conveyor (31) is provided with a third iron remover (38). The second iron remover (37) and the third iron remover (38) respectively remove iron from the materials on the corresponding conveyors.

7. The continuous screening system for middlings based on lithium ore according to claim 1, characterized in that: A plurality of the screening machines are provided with a conveyor belt (34) for conveying the first-stage particles after screening, which can convey the first-stage particles after screening by the screening machines and convey them to the next process.

8. The continuous screening system for middlings based on lithium ore according to claim 1, characterized in that: The second belt conveyor (23) and the secondary particle return crushing conveyor (32) are respectively provided with a second belt conveyor trolley (24) and a secondary particle return crushing conveyor trolley (33).

9. The screening method of the continuous screening system for middling ore based on lithium ore according to any one of claims 1 to 8, characterized in that: include: The lithium ore is crushed for the first time. After the material is crushed for the first time, it enters the three-stage screening machine for three-stage screening. The first-level particles obtained enter the next process, and the second-level particles and third-level particles obtained return to the crushing process; After the secondary crushing of lithium ore, the secondary and tertiary particles are crushed at the corresponding level, and then enter the tertiary screening machine for tertiary screening. The particles after the second screening continue to be crushed and screened in a cycle until their particle size meets the requirements of the primary particles; The new lithium ore is crushed. While the previous lithium ore is being crushed in a cycle, the new lithium ore also begins to undergo primary and secondary crushing and enters a crushing cycle until the particle size meets the requirements of the primary particles.

10. The screening method of the lithium ore continuous screening system based on the middling ore according to claim 9, characterized in that: The lithium ore is subjected to iron removal treatment before each crushing.

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