Method for comprehensive recovery of iron and lepidolite based on hierarchical magnetic separation process

Abstract

The application discloses a method for comprehensively recovering iron lepidolite based on a hierarchical magnetic separation process, and belongs to the technical field of comprehensive ore dressing and recovery of lepidolite, and comprises the following steps: crushing and grinding, rough magnetic separation, hydraulic classification, coarse-grained strong magnetic scavenging, mixed concentrate strong magnetic separation, mixed concentrate strong magnetic scavenging, fine-grained strong magnetic rough separation, fine-grained strong magnetic separation and solid-liquid separation. According to the differences in physical and chemical properties of the iron lepidolite and associated minerals, such as mineral composition, element content, density, dissociation degree, specific magnetic susceptibility, particle size structure and settling velocity, a reasonable ore dressing process is selected, high-quality feldspar concentrate, high-quality iron lepidolite concentrate, medium-quality feldspar concentrate and medium-quality iron lepidolite concentrate are separated, the comprehensive recovery rate of the valuable minerals can reach 100%, tail water separated from the solid-liquid separation can be recycled after clarification, double-zero emission of tailings and tail water is realized, and a scientific and technical basis is provided for improving the ore dressing and recovery indexes of the iron lepidolite.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of comprehensive beneficiation of lepidolite, in particular to a method for comprehensive recovery of iron lepidolite based on a grading magnetic separation process. BACKGROUND

[0002] Lepidolite is the most common lithium mineral, which belongs to a kind of mica mineral, and is generally produced in granite pegmatite, often associated with tantalum-niobium ore, biotite, cassiterite, feldspar, quartz and other minerals. Iron-containing lepidolite is called iron lepidolite, which has weak magnetism and often appears in the form of fine flaky aggregates. Lepidolite is one of the main raw materials for extracting metallic lithium or lithium carbonate, and often contains rubidium and cesium, which are also important raw materials for extracting these rare metals. As a raw material for lithium chemicals, lepidolite is widely used in lithium batteries, metallurgy, glass, ceramics, medicine, chemical industry, military industry and other fields; with the rapid development of green and environmentally friendly new energy, the demand for lithium battery raw materials has increased significantly.

[0003] At present, domestic lepidolite processing enterprises mainly use the "desliming-flotation" process for beneficiation; with the development of strong magnetic separation process equipment and technology, some lepidolite processing enterprises also begin to use vertical ring high gradient magnetic separators to separate lepidolite; and some lepidolite processing enterprises use superconducting magnetic separators to recover fine-grained lepidolite in fine slurry; the above beneficiation processes can all produce qualified industrial products.

[0004] It is found through research that when using the "desliming-flotation" process, the hydrocyclone needs to be used to remove the fine slurry that affects the flotation index before using fatty acid to collect lepidolite, but part of the fine flaky lepidolite will also be lost in the fine slurry overflow, which will reduce the recovery rate of lepidolite; when using a vertical ring high gradient magnetic separator, although there is no environmental problem of reagent pollution, fine flaky lepidolite in fine particles cannot be effectively recovered; at the same time, when using a superconducting magnetic separator, although good beneficiation indexes can be obtained for fine lepidolite, it is difficult to realize large-scale production.

[0005] In view of the technical problems of high production cost, low beneficiation recovery rate, great environmental pressure, and small processing capacity existing in the existing beneficiation process, it is an urgent problem for lepidolite processing enterprises at this stage to design a method for comprehensive recovery of iron lepidolite, which can comprehensively recover valuable minerals by 100%, improve beneficiation recovery indexes, improve the quality of recovered products, achieve zero discharge of tailings and tail water, and be suitable for large-scale production and application. SUMMARY

[0006] In order to solve the problems in the prior art, the application provides a method for comprehensively recovering iron lepidolite based on a hierarchical magnetic separation process, a reasonable combined beneficiation process of crushing and grinding, rough magnetic separation, hydraulic classification, coarse particle rough magnetic separation, mixed concentrate rough magnetic separation, fine particle rough magnetic separation, fine particle rough magnetic separation, solid-liquid separation and the like is selected, four products of high-quality feldspar concentrate, high-quality iron lepidolite concentrate, medium-quality feldspar concentrate and medium-quality iron lepidolite concentrate are separated, the comprehensive recovery rate of the valuable minerals can reach 100%, the tail water separated by the solid-liquid separation can be recycled after clarification, double zero discharge of tailings and tail water is realized, scientific technical basis is provided for improving the beneficiation recovery index of the iron lepidolite and improving the quality of the byproduct feldspar concentrate, and the method is suitable for large-scale production and application.

[0007] In order to achieve the above object, the technical scheme adopted by the application is as follows:

[0008] The application provides a method for comprehensively recovering iron lepidolite based on a hierarchical magnetic separation process, and the method comprises the following steps:

[0009] S1: crushing and grinding: the raw ore is subjected to crushing and grinding operation to obtain a qualified particle size product; the crushing and grinding operation can make the iron lepidolite and the gangue minerals in the raw ore reach monomer dissociation, which is beneficial to improving the mineral separation index;

[0010] S2: rough magnetic separation: the qualified particle size product is slurried and subjected to magnetic separation operation under a first magnetic field strength to obtain first magnetic material and first non-magnetic material; the first magnetic material is a rough concentrate of the iron lepidolite with good monomer dissociation degree, and can take into account the quality and recovery rate and other beneficiation indexes of the product;

[0011] S3: hydraulic classification: the first non-magnetic material is subjected to hydraulic classification operation to obtain a fine particle product and a coarse particle product; the hydraulic classification operation can divide the first non-magnetic material into two products with different particle sizes, which is convenient for subsequent magnetic separation;

[0012] S4: coarse particle rough magnetic separation: the coarse particle product is subjected to magnetic separation operation under a second magnetic field strength to obtain second magnetic material and second non-magnetic material; the second non-magnetic material is discharged into a coarse particle tailing sedimentation tank; the coarse particle rough magnetic separation can separate the iron lepidolite contained in the coarse particle product as much as possible, reduce the content of lithium metal in the second non-magnetic material, and maximize the product recovery rate; the second non-magnetic material is high-quality feldspar concentrate;

[0013] S5: mixed concentrate rough magnetic separation: the first magnetic material and the second magnetic material are combined into a mixed concentrate, and the mixed concentrate is subjected to magnetic separation operation under a third magnetic field strength to obtain third magnetic material and third non-magnetic material; the third magnetic material is discharged into a coarse particle concentrate sedimentation tank; the third magnetic material is high-quality iron lepidolite concentrate, and the added value of the product is improved;

[0014] S6: mixed strong magnetic field scanning selection: the third non-magnetic material is subjected to magnetic separation operation under a fourth magnetic field strength to obtain fourth magnetic material and fourth non-magnetic material; the fourth magnetic material is discharged into the coarse particle grade concentrate sedimentation tank; the fourth magnetic material is high-quality iron-lithium mica concentrate selected from the third non-magnetic material, which improves the recovery rate and production benefit of the product; the fourth non-magnetic material is mixed into the coarse particle grade product, and the step S4 is performed, which can further improve the recovery rate of the coarse particle grade iron-lithium mica;

[0015] S7: fine particle strong magnetic field rough separation: the fine particle grade product is subjected to magnetic separation operation under a fifth magnetic field strength to obtain fifth magnetic material and fifth non-magnetic material; the fifth non-magnetic material is discharged into the fine particle grade tailing sedimentation tank; the fifth magnetic material is fine particle grade iron-lithium mica, which can effectively improve the recovery rate of the fine particle product; the fifth non-magnetic material is medium-quality feldspar concentrate;

[0016] S8: fine particle strong magnetic separation: the fifth magnetic material is subjected to magnetic separation operation under a sixth magnetic field strength to obtain sixth magnetic material and sixth non-magnetic material; the sixth magnetic material is discharged into the fine particle grade concentrate sedimentation tank, and the sixth magnetic material is medium-quality iron-lithium mica concentrate, which improves the added value of the product; the sixth non-magnetic material is mixed into the fine particle grade product, and the step S7 is performed, which can further improve the recovery rate of the fine particle grade iron-lithium mica;

[0017] S9: solid-liquid separation: the products in the coarse particle grade tailing sedimentation tank, the coarse particle grade concentrate sedimentation tank, the fine particle grade tailing sedimentation tank and the fine particle grade concentrate sedimentation tank are subjected to solid-liquid separation operation respectively, and the separated tail water is clarified and recycled.

[0018] As a preferred technical solution, in step S1, the raw ore is subjected to crushing operation using a jaw crusher and / or a cone crusher, and then subjected to grinding operation using a ball mill.

[0019] As a preferred technical solution, in step S2, the first magnetic field strength is set to 1.4-1.6 Tesla, magnetic separation operation is performed using a vertical ring high gradient magnetic separator, and the medium is high magnetic conductivity stainless steel rod.

[0020] As a preferred technical solution, in step S3, the first non-magnetic material is subjected to classification operation using a hydrocyclone; the overflow particle size of the hydrocyclone is set to 300-500 mesh; preferably, the overflow particle size is set to 400 mesh, that is, the obtained fine particle grade product is -400 mesh, and the coarse particle grade product is +400 mesh.

[0021] As a preferred technical solution, in step S4, the second magnetic field strength is set to 1.6-1.8 Tesla, magnetic separation operation is performed using a vertical ring high gradient magnetic separator, and the medium is high magnetic conductivity stainless steel rod.

[0022] As a preferred technical solution, in step S5, the third magnetic field strength is set to 1.4-1.6 Tesla, the magnetic separation operation is performed using a vertical ring high gradient magnetic separator, and the medium is set to a high-permeability stainless steel mesh.

[0023] As a preferred technical solution, in step S6, the fourth magnetic field strength is set to 1.6-1.8 Tesla, the magnetic separation operation is performed using a vertical ring high gradient magnetic separator, and the medium is set to a high-permeability stainless steel mesh.

[0024] As a preferred technical solution, in step S7, the fifth magnetic field strength is set to 1.6-1.8 Tesla, the magnetic separation operation is performed using an electromagnetic slurry high gradient magnetic separator, and the medium is set to a high-permeability stainless steel mesh.

[0025] As a preferred technical solution, in step S8, the sixth magnetic field strength is set to 1.4-1.6 Tesla, the magnetic separation operation is performed using an electromagnetic slurry high gradient magnetic separator, and the medium is set to a high-permeability stainless steel mesh.

[0026] As a preferred technical solution, in step S9, the product in the coarse particle grade tailings sedimentation tank is subjected to solid-liquid separation operation using a plate and frame filter press to obtain high-quality feldspar concentrate; the product in the coarse particle grade concentrate sedimentation tank is subjected to solid-liquid separation operation using a plate and frame filter press to obtain high-quality iron lithium mica concentrate; the product in the fine particle grade tailings sedimentation tank is subjected to solid-liquid separation operation using a ceramic filter to obtain medium-quality feldspar concentrate; and the product in the fine particle grade concentrate sedimentation tank is subjected to solid-liquid separation operation using a disc filter to obtain medium-quality iron lithium mica concentrate.

[0027] The beneficial effects of the present application are as follows:

[0028] 1. The present application selects a reasonable crushing and grinding, high-intensity magnetic roughing, hydraulic classification, coarse particle high-intensity magnetic scavenging, mixed concentrate high-intensity magnetic concentration, mixed concentrate high-intensity magnetic scavenging, fine particle high-intensity magnetic roughing, fine particle high-intensity magnetic concentration, and solid-liquid separation combined beneficiation process, which separates out four products of high-quality feldspar concentrate, high-quality iron lithium mica concentrate, medium-quality feldspar concentrate and medium-quality iron lithium mica concentrate, and the comprehensive recovery rate of valuable minerals can reach 100%, the tail water separated by solid-liquid separation can be recycled after clarification, realizing double zero discharge of tailings and tail water, providing a scientific technical basis for improving the beneficiation recovery index of iron lithium mica and improving the quality of byproduct feldspar concentrate, and being suitable for large-scale production and application.

[0029] 2、The present application is aimed at the differences in the physical and chemical properties of the mineral composition, element content, density, dissociation degree, specific magnetic susceptibility, particle size structure, settling velocity, etc. of iron lithium mica and associated minerals. The dissociated iron lithium mica after grinding is divided into two particle sizes, coarse and fine, suitable magnetic field strength is used, and a combination of equipment such as vertical ring high gradient magnetic separator, hydrocyclone, electromagnetic slurry high gradient magnetic separator, etc. is adopted, and suitable high permeability stainless steel rods, high permeability stainless steel mesh and combined media are selected, and the coarse and fine particle size iron lithium mica is effectively classified and high intensity magnetic separation, which can greatly improve the concentrate grade and product recovery rate and other beneficiation indexes. Compared with the conventional process, the recovery rate can be increased by 5-10%.

[0030] 3、The coarse and fine particle classification and magnetic separation process of the present application can separate high-quality and qualified iron lithium mica concentrate and feldspar and other industrial products from granite pegmatite. When the granite pegmatite contains valuable minerals such as tantalum ore, niobium ore, and tin stone, and reaches the industrial grade and has beneficiation value, the method of the present application can reasonably increase the processes of gravity separation and magnetic separation according to the differences in the physical and chemical properties of the minerals such as density and specific magnetic susceptibility, so as to achieve the purpose of comprehensive beneficiation and recovery, and is suitable for large-scale production and application. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The process flow chart of one embodiment of the method for comprehensive recovery of iron lithium mica based on the classification and magnetic separation process. DETAILED DESCRIPTION

[0032] In order to facilitate understanding of those skilled in the art, the present application will be further described below with reference to the accompanying drawings.

[0033] A certain iron-lithium mica concentrator in Hunan Province previously adopted the "desliming-flotation" process, and the loss rate of lithium in the fine sludge removed before flotation was about 15%, and the total recovery rate of beneficiation was about 75%. A large amount of fine sludge tailings exist problems such as resource waste, land occupation, environmental pollution, and harm to reservoir capacity. At the same time, the "desliming-flotation" process also has problems such as high reagent cost and great environmental pressure. Later, the iron-lithium mica concentrator carried out large-scale technical improvement, and the original "desliming-flotation" process was improved to a magnetic separation process. The specific process flow is to use a vertical ring high gradient magnetic separator for one roughing and two scavenging, and then combine the rough concentrate and the concentrate to be further treated by one cleaning and one scavenging. This magnetic separation process effectively solves the problems of environmental protection and tailings reservoir capacity, and the production capacity is also improved. However, the total recovery rate of beneficiation is about 76-78%, the total recovery rate of beneficiation is limited, and part of the fine and micro-fine iron-lithium mica in the tailings is still difficult to recover. The specific beneficiation situation is as follows: when the grade of Li2O in the raw ore is 0.52%, the content of Li2O in the tailings is 0.18%, and the sieve analysis result of the tailings particle size shows that the content of Li2O in the +200 mesh coarse particle size is 0.07%, and the content of Li2O in the -200+400 mesh particle size is 0.10%, indicating that the vertical ring high gradient magnetic separator has a high beneficiation recovery effect on coarse and medium particle size iron-lithium mica; the yield of -400 mesh fine particle size is 28-30%, and the content of Li2O is 0.24%, of which the content of Li2O in -600 mesh fine particle size is as high as 0.36%, indicating that the vertical ring high gradient magnetic separator cannot effectively recover fine and micro-fine iron-lithium mica; thereby causing the loss of lithium metal.

[0034] It is found through research that the use of superconducting magnetic separators for fine and micro-fine iron-lithium mica in fine particles can achieve good beneficiation recovery effect, but the superconducting magnetic separator has large equipment investment, low processing capacity, and high operation difficulty, and is difficult to realize large-scale production. It is found through experimental comparison that when the content of Li2O in the -400 mesh fine sludge removed by the flotation process is 0.29%, the content of Li2O in the tailings of the first high-intensity magnetic roughing using the superconducting magnetic separator is 0.07%, and the content of Li2O in the tailings of the first high-intensity magnetic roughing using the electromagnetic slurry high gradient magnetic separator is 0.09%, indicating that the electromagnetic slurry high gradient magnetic separator also has good beneficiation effect on fine iron-lithium mica. The electromagnetic slurry high gradient magnetic separator is usually applied to the impurity removal and purification of -325 mesh fine particle size kaolin, and has the advantages of mature technology, large processing capacity, high production efficiency, excellent separation index, wide application range, etc.

[0035] Please refer to Figure 1 and Table 1, for an embodiment of a method for comprehensively recovering iron-lithium mica based on a staged magnetic separation process provided by the iron-lithium mica concentrator, which includes the following steps:

[0036] S1: crushing and grinding: the raw ore is crushed to -15mm by jaw crusher and cone crusher, and then enters a wet ball mill and spiral classification closed-circuit grinding operation to achieve a qualified product with a grinding fineness of -200 mesh 60%;

[0037] S2: high-intensity magnetic roughing: the qualified product is mixed into a slurry with a concentration of 30%, which enters a vertical ring high-gradient magnetic separator for high-intensity magnetic roughing at a first magnetic field strength of 1.4-1.6 tesla, with a medium of φ2mm high-permeability stainless steel rods and a pulsation of 14-16 Hz, to pre-select coarse, medium and fine flaky iron-lithium mica with good dissociation (i.e. first magnetic material) with a Li2O grade of 1.40-1.50%; the remainder is first non-magnetic material;

[0038] S3: hydrocyclone classification: the first non-magnetic material enters a hydrocyclone for hydrocyclone classification to obtain -400 mesh fine particle product and +400 mesh coarse particle product;

[0039] S4: coarse particle high-intensity magnetic scavenging: the coarse particle product is mixed into a slurry with a concentration of 25%, which enters a vertical ring high-gradient magnetic separator for coarse particle high-intensity magnetic scavenging at a second magnetic field strength of 1.6-1.8 tesla, with a medium of φ2mm high-permeability stainless steel rods and a pulsation of 10-12 Hz, to magnetically separate iron-lithium mica with slightly lower specific susceptibility (i.e. second magnetic material) by increasing the magnetic field strength and reducing the pulsation, with a Li2O grade of 1.20-1.30% for the second magnetic material; the remainder is second non-magnetic material with a Li2O content of 0.06-0.08%, which is discharged into a coarse particle tailings settling tank;

[0040] S5: mixed concentrate high-intensity magnetic concentration: the first magnetic material and the second magnetic material are combined into a mixed concentrate with a Li2O grade of 1.35-1.45%, which enters a vertical ring high-gradient magnetic separator for mixed concentrate high-intensity magnetic concentration at a third magnetic field strength of 1.4-1.6 tesla, with a medium of high-permeability stainless steel mesh and a pulsation of 24-26 Hz, to magnetically separate high-quality iron-lithium mica concentrate (i.e. third magnetic material) with a Li2O grade of 1.90-2.0%, and the remainder is third non-magnetic material; the third magnetic material is discharged into a coarse particle concentrate settling tank;

[0041] S6: mixed concentrate strong magnetic scanning selection: the third non-magnetic material is put into the vertical ring high gradient magnetic separator to perform mixed concentrate strong magnetic scanning selection at a fourth magnetic field strength, the fourth magnetic field strength is 1.6-1.8 tesla, the medium is high permeability stainless steel mesh, and the pulsation is 28-30 Hz; high-quality lepidolite concentrate with a Li2O grade of 1.70-1.80% (i.e., the fourth magnetic material) is scanned and selected out, and the fourth magnetic material is discharged into the coarse particle grade concentrate sedimentation tank; the remaining is middlings with a Li2O grade of 0.30-0.40% (i.e., the fourth non-magnetic material), which can be mixed into the coarse particle grade product, and the S4 coarse particle strong magnetic scanning step can be performed to further recover Li2O;

[0042] S7: fine particle strong magnetic roughing: the fine particle grade product is mixed into a slurry with a concentration of 20%, and is put into the electromagnetic slurry high gradient magnetic separator to perform fine particle strong magnetic roughing at a fifth magnetic field strength, the fifth magnetic field strength is 1.6-1.8 tesla, the medium is narrow spacing, multi-level and high permeability stainless steel mesh, and lepidolite rough concentrate with a Li2O grade of 1.20-1.30% (i.e., the fifth magnetic material) is obtained, and the remaining is non-magnetic material with a Li2O content of 0.08-0.10% (i.e., the fifth non-magnetic material), which is discharged into the fine particle grade tailing sedimentation tank;

[0043] S8: fine particle strong magnetic cleaning: the fifth magnetic material is put into the electromagnetic slurry high gradient magnetic separator to perform fine particle strong magnetic cleaning at a sixth magnetic field strength, the sixth magnetic field strength is 1.4-1.6 tesla, the medium is wide spacing, multi-level and combined high permeability stainless steel mesh, and fine flaky lepidolite concentrate with a Li2O grade of 1.60-1.70% (i.e., the sixth magnetic material) is obtained, which is discharged into the fine particle grade concentrate sedimentation tank; the remaining is middlings with a Li2O content of 0.20-0.30% (i.e., the sixth non-magnetic material), which can be mixed into the fine particle grade product, and the S7 fine particle strong magnetic roughing step can be performed to further recover Li2O;

[0044] S9: solid-liquid separation: the non-magnetic material in the coarse particle grade tailing sedimentation tank is subjected to solid-liquid separation using a plate and frame filter, high-quality feldspar concentrate with a Fe2O3 content of 0.09% and a whiteness of 65.28% for ceramics can be obtained; the non-magnetic material in the fine particle grade tailing sedimentation tank is subjected to solid-liquid separation using a ceramic filter, fine particle grade feldspar concentrate with a Fe2O3 content of 0.21% and a whiteness of 50.32% for ceramics can be obtained; the magnetic material in the coarse particle grade concentrate sedimentation tank is subjected to solid-liquid separation using a plate and frame filter, coarse flaky high-quality lepidolite concentrate with a Li2O grade of 1.90-2.0% can be obtained; the magnetic material in the fine particle grade concentrate sedimentation tank is subjected to solid-liquid separation using a disc filter, fine flaky medium-quality lepidolite concentrate with a Li2O grade of 1.60-1.70% can be obtained; the comprehensive beneficiation recovery rate reaches 87-89%.

[0045] Table 1. Beneficiation indexes of comprehensive recovery of iron and lepidolite based on a grading magnetic separation process

[0046]

[0047] It should be noted that the beneficiation process of the embodiment adopts a green and environmentally friendly strong magnetic physical beneficiation process, and tail water produced by solid-liquid separation operation of all products can be returned to each operation process for recycling after clarification.

[0048] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for comprehensive recovery of lepidolite based on a staged magnetic separation process, characterized in that, The method comprises the following steps: S1: crushing and grinding: the raw ore is subjected to crushing and grinding operation to obtain qualified particle size product; S2: strong magnetic roughing: the qualified particle size product is subjected to magnetic separation operation at a first magnetic field strength after being slurried to obtain first magnetic substance and first non-magnetic substance; S3: hydraulic classification: the first non-magnetic substance is subjected to hydraulic classification operation to obtain fine particle level product and coarse particle level product; S4: coarse particle strong magnetic scavenging: the coarse particle level product is subjected to magnetic separation operation at a second magnetic field strength to obtain second magnetic substance and second non-magnetic substance; the second non-magnetic substance is discharged into a coarse particle level tailing sedimentation tank; S5: mixed concentrate strong magnetic cleaning: the first magnetic substance and the second magnetic substance are combined into mixed concentrate, and the mixed concentrate is subjected to magnetic separation operation at a third magnetic field strength to obtain third magnetic substance and third non-magnetic substance; the third magnetic substance is discharged into a coarse particle level concentrate sedimentation tank; S6: mixed concentrate strong magnetic scavenging: the third non-magnetic substance is subjected to magnetic separation operation at a fourth magnetic field strength to obtain fourth magnetic substance and fourth non-magnetic substance; the fourth magnetic substance is discharged into the coarse particle level concentrate sedimentation tank; the fourth non-magnetic substance is mixed into the coarse particle level product and subjected to step S4; S7: fine particle strong magnetic roughing: the fine particle level product is subjected to magnetic separation operation at a fifth magnetic field strength to obtain fifth magnetic substance and fifth non-magnetic substance; the fifth non-magnetic substance is discharged into a fine particle level tailing sedimentation tank; S8: fine particle strong magnetic cleaning: the fifth magnetic substance is subjected to magnetic separation operation at a sixth magnetic field strength to obtain sixth magnetic substance and sixth non-magnetic substance; the sixth magnetic substance is discharged into a fine particle level concentrate sedimentation tank; the sixth non-magnetic substance is mixed into the fine particle level product and subjected to step S7; S9: solid-liquid separation: the products in the coarse particle level tailing sedimentation tank, the coarse particle level concentrate sedimentation tank, the fine particle level tailing sedimentation tank and the fine particle level concentrate sedimentation tank are subjected to solid-liquid separation operation respectively, and the separated tail water is clarified and recycled.

2. The method according to claim 1, characterized in that, In step S1, the raw ore is subjected to crushing operation by using a jaw crusher and / or a cone crusher, and then subjected to grinding operation by using a ball mill.

3. The method according to claim 1, characterized in that, In step S2, the first magnetic field strength is set to 1.4-1.6 Tesla, and the magnetic separation operation is performed by using a vertical ring high gradient magnetic separator, and the medium is high magnetic stainless steel rod.

4. The method according to claim 1, characterized in that, In step S3, the first non-magnetic substance is subjected to classification operation by using a hydrocyclone; the overflow particle size of the hydrocyclone is set to 300-500 mesh.

5. The method according to claim 1, characterized in that, In step S4, the second magnetic field strength is set to 1.6-1.8 Tesla, and the magnetic separation operation is performed by using a vertical ring high gradient magnetic separator, and the medium is high magnetic stainless steel rod.

6. The method according to claim 1, characterized in that, In step S5, the third magnetic field strength is set to 1.4-1.6 Tesla, and the magnetic separation operation is performed by using a vertical ring high gradient magnetic separator, and the medium is high magnetic stainless steel plate net.

7. The method according to claim 1, characterized in that, In step S6, the fourth magnetic field strength is set to 1.6-1.8 Tesla, and the magnetic separation operation is performed by using a vertical ring high gradient magnetic separator, and the medium is high magnetic stainless steel plate net.

8. The method according to claim 1, characterized in that, In step S7, the fifth magnetic field strength is set to 1.6-1.8 Tesla, the magnetic separation operation is performed using an electromagnetic slurry high-gradient magnetic separator, and the medium is set to a high-permeability stainless steel plate net.

9. The method according to claim 1, characterized in that, In step S8, the sixth magnetic field strength is set to 1.4-1.6 Tesla, the magnetic separation operation is performed using an electromagnetic slurry high-gradient magnetic separator, and the medium is set to a high-permeability stainless steel plate net.

10. The method according to claim 1, characterized in that, In step S9, the product in the coarse particle grade tailings sedimentation tank is subjected to solid-liquid separation operation using a plate-and-frame filter press, to obtain high-quality feldspar concentrate; the product in the coarse particle grade concentrate sedimentation tank is subjected to solid-liquid separation operation using a plate-and-frame filter press, to obtain high-quality iron lepidolite concentrate; the product in the fine particle grade tailings sedimentation tank is subjected to solid-liquid separation operation using a ceramic filter, to obtain medium-quality feldspar concentrate; and the product in the fine particle grade concentrate sedimentation tank is subjected to solid-liquid separation operation using a disc filter, to obtain medium-quality iron lepidolite concentrate.

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