A weak magnetic lepidolite pre-elutriation waste-flotation enrichment method

Abstract

The present application relates to a kind of weak magnetic lepidolite pre-elution waste-flotation enrichment method, belong to mineral processing technical field.The present application carries out coarse grinding, slurry conditioning to low-grade weak magnetic lepidolite, is pre-elution waste by high gradient magnetic separation, obtains coarse-grained high-grade lithium-containing magnetic product, again by concentration, fine grinding treatment, adds composite regulator and composite collector to carry out the selective regulation of slurry environment and mineral surface characteristics, using two roughing, once scavenging, once concentration can obtain high-quality lithium concentrate.The present application removes most of the gangue in the ore by magnetic separation, and once enrichment of weak magnetic lepidolite greatly reduces the ore processing capacity of subsequent process;Adopting fine grinding realizes that lithium mica is fully dissociated, and the new composite reagent developed is used to carry out selective hydrophobic flotation to lithium-containing magnetic product, which can realize secondary enrichment of weak magnetic lepidolite, and provides a new method for clean separation and efficient recovery of low-grade complex and difficult-to-select lithium ore.

Description

Technical Field

[0001] This invention relates to a pre-selection, waste disposal, and flotation enrichment method for weakly magnetic lepidolite, belonging to the field of mineral processing technology. Background Technology

[0002] Lithium is an important new energy metal, and lepidolite is a common lithium mineral, generally found in granite pegmatite deposits. It often contains rubidium and cesium and is also an important raw material for extracting these rare metals. During mineralization, lepidolite is easily replaced by iron and manganese, exhibiting a certain degree of weak magnetism. Its magnetic susceptibility differs significantly from gangue minerals such as muscovite, feldspar, and quartz, but it often exists as flaky aggregates. During grinding, a large amount of fine-grained weakly magnetic lepidolite is generated, making it difficult to effectively recover this portion of lithium mineral using magnetic separation. Furthermore, due to the substitution of the crystal lattice, the crystal characteristics, surface structure, and properties of weakly magnetic lepidolite change, leading to corresponding changes in its floatability, making it difficult to effectively collect using conventional flotation reagents.

[0003] Weakly magnetic lepidolite ore typically has low lithium content. Direct fine grinding is not only expensive due to the large ore throughput of the grinding process, but also incurrs significant investment in equipment, reagents, and dewatering costs in subsequent beneficiation processes. Therefore, there is an urgent need to optimize the processing technology for weakly magnetic lepidolite ore. The slurry of weakly magnetic lepidolite ore contains a large amount of primary and secondary slime particles, which strongly adsorb flotation reagents without selectively covering the target mineral surface, thus deteriorating the slurry environment. Furthermore, gangue minerals such as feldspar and quartz in the ore have similar surface properties to weakly magnetic lepidolite, making separation with conventional flotation reagents difficult. Currently, most beneficiation plants use a method of first desliming, followed by flotation of the deslimed coarse sand. However, the deslimed slime still contains a large amount of weakly magnetic lepidolite, resulting in severe lithium metal loss and unsatisfactory beneficiation performance.

[0004] Therefore, it is urgent to develop new process flows that match the properties of weakly magnetic lepidolite ore, and at the same time, to develop targeted flotation reagents to selectively regulate weakly magnetic lepidolite ore, so as to achieve efficient and green recovery of weakly magnetic lepidolite and thus improve the comprehensive utilization rate of complex and difficult-to-process lithium ore resources. Summary of the Invention

[0005] To address the problems of low separation efficiency, poor performance indicators, high energy consumption, and high reagent costs associated with conventional beneficiation techniques for recovering low-grade weakly magnetic lepidolite ore, this invention provides a pre-selection waste disposal-flotation enrichment method for weakly magnetic lepidolite ore. Based on a combined magnetic separation-flotation process, it employs segmented grinding and secondary enrichment methods. High-gradient magnetic separation is used to pre-enrich coarse-grained weakly magnetic lepidolite ore, significantly reducing the ore processing volume in subsequent processes, greatly reducing grinding energy consumption and costs, and decreasing the number of separation equipment and flotation reagents required. Without desliming, a flotation process consisting of two roughing stages, one scavenging stage, and one cleaning stage further enriches the fully liberated lithium-containing magnetic product, yielding high-quality lithium concentrate. This method achieves efficient and rapid flotation of lepidolite ore under short-process conditions, solving the problems of long process flow, low efficiency, and poor performance indicators inherent in conventional flotation processes.

[0006] A pre-selection waste-flotation enrichment method for weakly magnetic lepidolite, the specific steps of which are as follows:

[0007] (1) The weakly magnetic lithium mica ore is crushed and coarsely ground, and then water is added to adjust the slurry mass percentage concentration to 10-20%;

[0008] (2) The slurry obtained in step (1) is subjected to a high gradient magnetic separator for a first magnetic separation operation to obtain a first magnetic concentrate and a first magnetic tailings;

[0009] (3) The tailings obtained from the primary magnetic separation in step (2) are subjected to secondary magnetic separation by a high-gradient magnetic separator to obtain secondary magnetic concentrate and secondary magnetic tailings; the secondary magnetic tailings are waste rock;

[0010] (4) Combine the primary magnetic separation concentrate obtained in step (2) and the secondary magnetic separation concentrate obtained in step (3) to obtain a coarse-grained high-grade lithium-containing magnetic product. Then, concentrate and finely grind the lithium-containing magnetic product, and add water to adjust the slurry mass percentage concentration to 24-36%.

[0011] (5) Add composite modifier and composite collector to the slurry obtained in step (4) in sequence, and perform a first flotation roughing operation to obtain a first flotation roughing concentrate and a first flotation roughing tailings;

[0012] (6) Add composite modifier and composite collector to the primary flotation roughing tailings obtained in step (5) in sequence, and carry out secondary flotation roughing operation to obtain secondary flotation roughing concentrate and secondary flotation roughing tailings;

[0013] (7) Add composite modifier and composite collector to the roughing tailings obtained in step (6) and perform flotation machine scavenging operation to obtain flotation machine scavenging concentrate and flotation machine scavenging tailings; wherein the flotation machine scavenging concentrate is returned to the pulp conditioning and fed into the roughing operation of the secondary flotation machine; the flotation machine scavenging tailings are tailings;

[0014] (8) Combine the primary flotation rough concentrate obtained in step (5) and the secondary flotation rough concentrate obtained in step (6) and add a composite collector after slurry conditioning to perform flotation cleaning operation to obtain flotation clean concentrate and flotation clean tailings, wherein the flotation clean tailings are returned to slurry conditioning and incorporated into the secondary flotation roughing operation; the flotation clean concentrate is lithium concentrate;

[0015] The composite modifier is a mixture of sodium carbonate and polyaluminum chloride, and the composite collector is a mixture of dodecylamine, sodium cocoyl sulfate, dodecyl dihydroxyethyl methyl ammonium chloride, and ethoxylated alkyl sulfate.

[0016] Preferably, the mass percentage of Li2O in the weakly magnetic lithium mica ore in step (1) is 0.34~0.62%.

[0017] Preferably, the magnetic field strength of the first magnetic separation operation in step (2) is 1.5~1.7T.

[0018] Preferably, the magnetic field strength of the secondary magnetic separation operation in step (3) is 1.6~1.8T.

[0019] Preferably, per ton of lithium-containing magnetic product, 420-660g of composite modifier and 300-540g of composite collector are added to the slurry in the primary flotation roughing operation of step (5).

[0020] Preferably, for every ton of lithium-containing magnetic product, 210-330g of composite modifier and 150-270g of composite collector are added to the slurry in the roughing operation of the secondary flotation machine in step (6).

[0021] Preferably, 70-110g of composite modifier and 50-90g of composite collector are added to the slurry of the flotation machine sweeping operation in step (7) per ton of lithium-containing magnetic product.

[0022] Preferably, 25-45g of compound collector is added to the slurry of the flotation machine in step (8) per ton of lithium-containing magnetic product.

[0023] Preferably, based on a mass fraction of 100% for the composite modifier, sodium carbonate accounts for 60-80% and polyaluminum chloride accounts for 20-40%.

[0024] Preferably, based on a mass fraction of 100% for the composite collector, the composite collector contains 30-40% dodecylamine, 35-45% sodium cocoyl sulfate, 10-20% dodecyl dihydroxyethyl methyl ammonium chloride, and 5-15% ethoxylated alkyl sulfate.

[0025] The beneficial effects of this invention are:

[0026] (1) Based on the magnetic separation-flotation combined process, the present invention adopts the segmented grinding and secondary enrichment method. The coarse-grained weak magnetic lithium mica ore is pre-enriched by high gradient magnetic separation. Under the condition of no desliming, the fully liberated lithium-containing magnetic product is further enriched by the flotation process of two roughing, one scavenging and one cleaning to obtain high-quality lithium concentrate. This realizes the green and efficient separation of low-grade weak magnetic lithium mica ore.

[0027] (2) The present invention uses high gradient magnetic separation for pre-selection and waste removal, which removes most of the gangue in the ore, avoids all the ore from entering the fine grinding process, greatly reduces grinding energy consumption and cost, and effectively optimizes the grinding process; while improving the feed grade of the flotation process, it also greatly reduces the amount of ore processed in the flotation process, which not only reduces the number of sorting equipment, but also greatly reduces the amount of flotation reagents used, resulting in significant economic and environmental benefits;

[0028] (3) The present invention uses fine grinding to fully dissociate lepidolite in lithium-containing magnetic products, creating conditions for efficient separation of lepidolite and gangue minerals in subsequent flotation. By selectively controlling the pulp environment and mineral surface characteristics through the developed new composite reagent, efficient and rapid flotation of lepidolite ore is achieved under short process conditions, solving the problems of long process, low efficiency and poor index of conventional flotation process.

[0029] (4) Based on the matching characteristics between flotation reagents and mineral surfaces, the composite modifier developed in this invention can selectively adsorb onto the surface of gangue particles, and the composite collector can target hydrophobicity of lepidolite, greatly improving the difference in floatability between minerals and improving the stability, fluidity and viscosity of flotation foam. It can not only float bubbles carrying lepidolite to the liquid surface to form a mineralized foam layer, but also quickly defoam and discharge ore, providing a new method for the clean separation and efficient recovery of low-grade complex and difficult-to-process lithium ore. Attached Figure Description

[0030] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0032] In this embodiment of the invention, the composite modifier is a mixture of sodium carbonate and polyaluminum chloride, and the composite collector is a mixture of dodecylamine, sodium cocoyl sulfate, dodecyl dihydroxyethyl methyl ammonium chloride, and ethoxylated alkyl sulfate.

[0033] Example 1: In this example, with the mass fraction of the composite modifier being 100%, sodium carbonate accounts for 60% and polyaluminum chloride accounts for 40%; with the mass fraction of the composite collector being 100%, dodecylamine accounts for 30%, sodium cocoyl sulfate accounts for 45%, dodecyl dihydroxyethyl methyl ammonium chloride accounts for 20%, and ethoxylated alkyl sulfate accounts for 5%.

[0034] like Figure 1 As shown, a pre-selection waste-flotation enrichment method for weakly magnetic lepidolite is described, with the following specific steps:

[0035] (1) The weakly magnetic lithium mica ore is crushed and coarsely ground, and then water is added to adjust the mass percentage concentration of the slurry to 10%; wherein the mass percentage content of Li2O in the weakly magnetic lithium mica ore is 0.34%;

[0036] (2) The slurry obtained in step (1) is subjected to a high gradient magnetic separator for a first magnetic separation operation to obtain a first magnetic concentrate and a first magnetic tailings; wherein the magnetic field strength of the first magnetic separation operation is 1.5T;

[0037] (3) The tailings obtained from the primary magnetic separation in step (2) are subjected to secondary magnetic separation by a high gradient magnetic separator to obtain secondary magnetic concentrate and secondary magnetic tailings; the secondary magnetic tailings are waste rock; the magnetic field strength of the secondary magnetic separation operation is 1.6T.

[0038] (4) Combine the primary magnetic separation concentrate obtained in step (2) and the secondary magnetic separation concentrate obtained in step (3) to obtain a coarse-grained high-grade lithium-containing magnetic product. Then, concentrate and finely grind the lithium-containing magnetic product, and add water to adjust the slurry mass percentage concentration to 24%.

[0039] (5) Add composite modifier and composite collector to the slurry obtained in step (4) in sequence, and perform a first flotation roughing operation to obtain a first flotation roughing concentrate and a first flotation roughing tailings; 420g of composite modifier and 300g of composite collector are added to the slurry of the first flotation roughing operation per ton of lithium-containing magnetic product.

[0040] (6) Add composite modifier and composite collector to the primary flotation roughing tailings obtained in step (5) in sequence, and carry out secondary flotation roughing operation to obtain secondary flotation roughing concentrate and secondary flotation roughing tailings; add 210g of composite modifier and 150g of composite collector to the slurry of the secondary flotation roughing operation per ton of lithium-containing magnetic product.

[0041] (7) Add composite modifier and composite collector to the roughing tailings obtained in step (6) in sequence, and perform flotation machine scavenging operation to obtain flotation machine scavenging concentrate and flotation machine scavenging tailings; wherein the flotation machine scavenging concentrate is returned to the pulp conditioning and incorporated into the roughing operation of the secondary flotation machine; the flotation machine scavenging tailings are tailings; based on each ton of lithium-containing magnetic product, add 70g of composite modifier and 50g of composite collector to the pulp of the flotation machine scavenging operation;

[0042] (8) Combine the primary flotation rough concentrate obtained in step (5) and the secondary flotation rough concentrate obtained in step (6) and add a composite collector after adjusting the slurry. Then, perform flotation cleaning operation to obtain flotation clean concentrate and flotation clean tailings. The flotation clean tailings are returned to the slurry and incorporated into the secondary flotation roughing operation. The flotation clean concentrate is lithium concentrate. 25g of composite collector is added to the slurry of the flotation cleaning operation per ton of lithium-containing magnetic product.

[0043] In this embodiment, the lithium flotation recovery rate was 83.4%.

[0044] Example 2: In this example, with the mass fraction of the composite modifier being 100%, sodium carbonate accounts for 70% and polyaluminum chloride accounts for 30%; with the mass fraction of the composite collector being 100%, dodecylamine accounts for 35%, sodium cocoyl sulfate accounts for 35%, dodecyl dihydroxyethyl methyl ammonium chloride accounts for 15%, and ethoxylated alkyl sulfate accounts for 15%.

[0045] like Figure 1 As shown, a pre-selection waste-flotation enrichment method for weakly magnetic lepidolite is described, with the following specific steps:

[0046] (1) The weakly magnetic lithium mica ore is crushed and coarsely ground, and then water is added to adjust the mass percentage concentration of the slurry to 15%; wherein the mass percentage content of Li2O in the weakly magnetic lithium mica ore is 0.48%;

[0047] (2) The slurry obtained in step (1) is subjected to a high gradient magnetic separator for a first magnetic separation operation to obtain a first magnetic concentrate and a first magnetic tailings; wherein the magnetic field strength of the first magnetic separation operation is 1.6T;

[0048] (3) The tailings obtained from the primary magnetic separation in step (2) are subjected to secondary magnetic separation by a high gradient magnetic separator to obtain secondary magnetic concentrate and secondary magnetic tailings; the secondary magnetic tailings are waste rock; the magnetic field strength of the secondary magnetic separation operation is 1.7T;

[0049] (4) Combine the primary magnetic separation concentrate obtained in step (2) and the secondary magnetic separation concentrate obtained in step (3) to obtain a coarse-grained high-grade lithium-containing magnetic product. Then, concentrate and finely grind the lithium-containing magnetic product, and add water to adjust the slurry mass percentage concentration to 30%.

[0050] (5) Add composite modifier and composite collector to the slurry obtained in step (4) in sequence, and perform a first flotation roughing operation to obtain a first flotation roughing concentrate and a first flotation roughing tailings; 540g of composite modifier and 420g of composite collector are added to the slurry of the first flotation roughing operation per ton of lithium-containing magnetic product.

[0051] (6) Add composite modifier and composite collector to the primary flotation roughing tailings obtained in step (5) in sequence, and carry out secondary flotation roughing operation to obtain secondary flotation roughing concentrate and secondary flotation roughing tailings; add 270g of composite modifier and 210g of composite collector to the slurry of the secondary flotation roughing operation per ton of lithium-containing magnetic product.

[0052] (7) Add composite modifier and composite collector to the roughing tailings obtained in step (6) in sequence, and perform flotation machine scavenging operation to obtain flotation machine scavenging concentrate and flotation machine scavenging tailings; wherein the flotation machine scavenging concentrate is returned to the pulp conditioning and incorporated into the roughing operation of the secondary flotation machine; the flotation machine scavenging tailings are tailings; based on each ton of lithium-containing magnetic product, add 90g of composite modifier and 70g of composite collector to the pulp of the flotation machine scavenging operation;

[0053] (8) Combine the primary flotation rough concentrate obtained in step (5) and the secondary flotation rough concentrate obtained in step (6) and add a composite collector after adjusting the slurry. Then, perform flotation cleaning operation to obtain flotation clean concentrate and flotation clean tailings. The flotation clean tailings are returned to the slurry and incorporated into the secondary flotation roughing operation. The flotation clean concentrate is lithium concentrate. 35g of composite collector is added to the slurry of the flotation cleaning operation per ton of lithium-containing magnetic product.

[0054] In this embodiment, the lithium flotation recovery rate was 84.6%.

[0055] Example 3: In this example, with the mass fraction of the composite modifier being 100%, sodium carbonate accounts for 80% and polyaluminum chloride accounts for 20%; with the mass fraction of the composite collector being 100%, dodecylamine accounts for 40%, sodium cocoyl sulfate accounts for 40%, dodecyl dihydroxyethyl methyl ammonium chloride accounts for 10%, and ethoxylated alkyl sulfate accounts for 10%.

[0056] like Figure 1 As shown, a pre-selection waste-flotation enrichment method for weakly magnetic lepidolite is described, with the following specific steps:

[0057] (1) The weakly magnetic lithium mica ore is crushed and coarsely ground, and then water is added to adjust the mass percentage concentration of the slurry to 20%; wherein the mass percentage content of Li2O in the weakly magnetic lithium mica ore is 0.62%;

[0058] (2) The slurry obtained in step (1) is subjected to a high gradient magnetic separator for a first magnetic separation operation to obtain a first magnetic concentrate and a first magnetic tailings; wherein the magnetic field strength of the first magnetic separation operation is 1.7T;

[0059] (3) The tailings obtained from the primary magnetic separation in step (2) are subjected to secondary magnetic separation by a high gradient magnetic separator to obtain secondary magnetic concentrate and secondary magnetic tailings; the secondary magnetic tailings are waste rock; the magnetic field strength of the secondary magnetic separation operation is 1.8T.

[0060] (4) Combine the primary magnetic separation concentrate obtained in step (2) and the secondary magnetic separation concentrate obtained in step (3) to obtain a coarse-grained high-grade lithium-containing magnetic product. Then, concentrate and finely grind the lithium-containing magnetic product, and add water to adjust the slurry mass percentage concentration to 36%.

[0061] (5) Add composite modifier and composite collector to the slurry obtained in step (4) in sequence, and perform a first flotation roughing operation to obtain a first flotation roughing concentrate and a first flotation roughing tailings; 660g of composite modifier and 540g of composite collector are added to the slurry of the first flotation roughing operation per ton of lithium-containing magnetic product.

[0062] (6) Add composite modifier and composite collector to the primary flotation roughing tailings obtained in step (5) in sequence, and carry out secondary flotation roughing operation to obtain secondary flotation roughing concentrate and secondary flotation roughing tailings; add 330g of composite modifier and 270g of composite collector to the slurry of the secondary flotation roughing operation per ton of lithium-containing magnetic product.

[0063] (7) Add composite modifier and composite collector to the roughing tailings obtained in step (6) in sequence, and perform flotation machine scavenging operation to obtain flotation machine scavenging concentrate and flotation machine scavenging tailings; wherein the flotation machine scavenging concentrate is returned to the pulp conditioning and incorporated into the roughing operation of the secondary flotation machine; the flotation machine scavenging tailings are tailings; based on each ton of lithium-containing magnetic product, add 110g of composite modifier and 90g of composite collector to the pulp of the flotation machine scavenging operation;

[0064] (8) Combine the primary flotation rough concentrate obtained in step (5) and the secondary flotation rough concentrate obtained in step (6) and add a composite collector after slurry conditioning to carry out flotation cleaning operation to obtain flotation clean concentrate and flotation clean tailings. The flotation clean tailings are returned to slurry conditioning and incorporated into the secondary flotation roughing operation. The flotation clean concentrate is lithium concentrate. 45g of composite collector is added to the slurry of the flotation cleaning operation per ton of lithium-containing magnetic product.

[0065] In this embodiment, the lithium flotation recovery rate was 85.3%.

[0066] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for pre-selection and waste disposal-flotation enrichment of weakly magnetic lepidolite, characterized in that, The specific steps are as follows: (1) The weakly magnetic lithium mica ore is crushed and coarsely ground, and then water is added to adjust the slurry mass percentage concentration to 10-20%; (2) The slurry obtained in step (1) is subjected to a high gradient magnetic separator for a first magnetic separation operation to obtain a first magnetic concentrate and a first magnetic tailings; (3) The tailings obtained from the primary magnetic separation in step (2) are subjected to secondary magnetic separation by a high-gradient magnetic separator to obtain secondary magnetic concentrate and secondary magnetic tailings; the secondary magnetic tailings are waste rock; (4) Combine the primary magnetic separation concentrate obtained in step (2) and the secondary magnetic separation concentrate obtained in step (3) to obtain a coarse-grained high-grade lithium-containing magnetic product. Then, concentrate and finely grind the lithium-containing magnetic product, and add water to adjust the slurry mass percentage concentration to 24-36%. (5) Add composite modifier and composite collector to the slurry obtained in step (4) in sequence, and perform a first flotation roughing operation to obtain a first flotation roughing concentrate and a first flotation roughing tailings; (6) Add composite modifier and composite collector to the primary flotation roughing tailings obtained in step (5) in sequence, and carry out secondary flotation roughing operation to obtain secondary flotation roughing concentrate and secondary flotation roughing tailings; (7) Add composite modifier and composite collector to the roughing tailings obtained in step (6) and perform flotation machine scavenging operation to obtain flotation machine scavenging concentrate and flotation machine scavenging tailings; wherein the flotation machine scavenging concentrate is returned to the pulp conditioning and fed into the roughing operation of the secondary flotation machine; the flotation machine scavenging tailings are tailings; (8) Combine the primary flotation rough concentrate obtained in step (5) and the secondary flotation rough concentrate obtained in step (6) and add a composite collector after slurry conditioning to perform flotation cleaning operation to obtain flotation clean concentrate and flotation clean tailings, wherein the flotation clean tailings are returned to slurry conditioning and incorporated into the secondary flotation roughing operation; the flotation clean concentrate is lithium concentrate; The composite modifier is a mixture of sodium carbonate and polyaluminum chloride, and the composite collector is a mixture of dodecylamine, sodium cocoyl sulfate, dodecyl dihydroxyethyl methyl ammonium chloride, and ethoxylated alkyl sulfate.

2. The method for pre-selection, waste disposal, and flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: Step (1) The mass percentage of Li2O in the weakly magnetic lithium mica ore is 0.34~0.62%.

3. The method for pre-selection, waste disposal, and flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: Step (2) The magnetic field strength of a single magnetic separation operation is 1.5~1.7T.

4. The method for pre-selection, waste disposal, and flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: The magnetic field strength of the secondary magnetic separation operation in step (3) is 1.6~1.8T.

5. The method for pre-selection and waste disposal-flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: For every ton of lithium-containing magnetic product, 420-660g of composite modifier and 300-540g of composite collector are added to the slurry in the first flotation roughing operation in step (5).

6. The method for pre-selection and waste disposal-flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: For every ton of lithium-containing magnetic product, 210-330g of composite modifier and 150-270g of composite collector are added to the slurry in the roughing operation of the secondary flotation machine in step (6).

7. The method for pre-selection, waste disposal, and flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: For every ton of lithium-containing magnetic product, 70-110g of composite modifier and 50-90g of composite collector are added to the slurry in the flotation machine sweeping operation in step (7).

8. The method for pre-selection, waste disposal, and flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: For every ton of lithium-containing magnetic product, 25-45g of composite collector is added to the slurry in the flotation machine in step (8).

9. The method for pre-selection, waste disposal, and flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: Based on a mass fraction of 100% for the composite modifier, sodium carbonate accounts for 60-80% and polyaluminum chloride accounts for 20-40%.

10. The method for pre-selection, waste disposal, and flotation enrichment of weakly magnetic lithium mica ore according to claim 1, characterized in that: Based on a mass fraction of 100% for the compound collector, the compound collector contains 30-40% dodecylamine, 35-45% sodium cocoyl sulfate, 10-20% dodecyl dihydroxyethyl methyl ammonium chloride, and 5-15% ethoxylated alkyl sulfate.

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