A beneficiation method for enriching and recovering lithium from a primary clay type lithium mine

Abstract

The application discloses a beneficiation method for enriching and recovering lithium from a primary clay type lithium ore. The beneficiation method comprises the following steps: S1, crushing the primary clay type lithium ore to 2 mm; S2, adding water to the crushed ore to adjust the ore mass concentration to 30-40%, and placing the ore in a stirring container for full soaking and stirring; S3, grading the stirred ore slurry to 0.1 mm, and grinding the coarse particles to 0.1 mm; S4, grading the ground and graded product to obtain sand and overflow; and S5, adjusting the overflow for reverse flotation, wherein the reverse flotation adopts a three-stage flotation, the first-stage flotation adopts a 1-coarse-2-precious-2-sweep open-circuit flotation, the second-stage flotation adopts a 1-coarse-2-sweep open-circuit flotation by combining the middlings of the first stage, and the third-stage flotation adopts a 1-coarse-1-precious-1-sweep closed-circuit flotation by using the middlings of the second stage, and the in-tank product of the reverse flotation operation is combined to serve as a lithium concentrate. The method can increase the Li2O grade of the primary clay lithium concentrate to more than 0.8%, and the recovery rate is more than 65%.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a mineral processing method for enriching and recovering lithium from primary clay-type lithium ore. Background Technology

[0002] Lithium is hailed as the "energy metal" of the 21st century and is currently widely used in the battery industry. With increasing global focus on carbon emissions, clean energy technologies are developing rapidly, leading to a surge in market demand for lithium and a corresponding rise in lithium prices. Lithium processing and extraction methods are also currently a hot research topic.

[0003] Currently, lithium is mainly extracted from salt lakes or hard-rock lithium ores. For ore extraction, the raw materials are primarily spodumene, lepidolite, and petalite. Spodumene concentrate contains 5%–7% Li₂O, lepidolite concentrate contains 1%–3% Li₂O, and petalite concentrate contains 3%–4% Li₂O. Higher Li₂O grades in lithium concentrate result in lower lithium salt production costs and less slag. Before 2020, lithium prices were low, and only spodumene could be used as a raw material for lithium extraction. With rising lithium prices, lithium extraction from lepidolite has become more widespread. For example, Yichun in Jiangxi Province has the world's largest lepidolite deposit, which is now fully developed.

[0004] Clay-type lithium resources, as a type of lithium ore, are abundant, but due to their special properties, they have not been well developed and utilized for a long time. Globally, clay-type resources are still in the research and development stage, but they have great potential in the long run and are of great significance in alleviating the lithium supply difficulties.

[0005] A certain area in Guizhou, my country, possesses abundant clay-type lithium deposits. In these primary clay-type lithium deposits, the ore is a dense, dark brown mass. Lithium is primarily found in lithium chlorite (27% mineral content), along with significant amounts of illite (11%), kaolinite (4%), and other clay minerals. Other minerals include quartz (31%), calcite (18%), dolomite (3.5%), pyrite (1.7%), and limonite (1.7%). The lithium chlorite and clay minerals (including illite and kaolinite) have fine grain sizes, primarily distributed within the -0.04 mm range, with -0.005 mm grain sizes accounting for 40.71% and 47.11%, respectively. The carbonates (mainly calcite) and quartz have relatively coarser grain sizes, primarily distributed within the -0.16 mm range, with -0.005 mm grain sizes accounting for 12.32% and 18.93%, respectively. The raw ore contains 0.4%–0.6% Li₂O and approximately 42% clay minerals, making it relatively difficult to process. Removing quartz and carbonates can enrich the lithium grade by nearly 100%, which is beneficial for improving the grade of lithium clay ore and is of great significance for reducing subsequent smelting costs and decreasing solid hazardous waste. Summary of the Invention

[0006] The purpose of this invention is to provide a beneficiation method for enriching and recovering lithium from primary clay-type lithium ore. The method proposed in this invention can increase the Li2O grade of primary clay lithium concentrate to more than 0.8% and the recovery rate to more than 65%.

[0007] This invention is achieved through the following technical solutions:

[0008] A mineral processing method for enriching and recovering lithium from primary clay-type lithium ore includes the following steps:

[0009] S1. Crush the primary clay-type lithium ore to below 2mm (-2mm);

[0010] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 30% to 40%, and place it in a mixing container for thorough soaking and stirring;

[0011] S3. The stirred slurry is classified into 0.1mm particles, and the coarse particles are ground to below 0.1mm (-0.1mm);

[0012] S4. Classify the graded grinding product obtained in step S3 to obtain underflow and overflow.

[0013] S5. The overflow is subjected to slurry adjustment and reverse flotation. The reverse flotation adopts a three-stage flotation process. The first stage flotation process is 1 roughing, 2 cleaning, and 2 scavenging open-circuit flotation. The second stage flotation process is to combine the middlings from the first stage and perform 1 roughing and 2 scavenging open-circuit flotation. The third stage flotation process is to combine the middlings from the second stage and perform 1 roughing, 1 cleaning, and 1 scavenging closed-circuit flotation. The products in the tank from the reverse flotation operation are combined as lithium concentrate.

[0014] Preferably, the primary clay-type lithium ore mentioned in step S1 is a bottom primary ore with a Li2O content of 0.5% to 0.6%.

[0015] Preferably, the stirring and soaking conditions in step S2 are: stirring speed of 800-1200 rpm and stirring and soaking time of 30-60 min.

[0016] Preferably, the grading particle size in step S4 is 0.025 to 0.045 mm.

[0017] Preferably, the reverse flotation activator in step S5 is calcium chloride, with a total dosage of 100-200 g / t; the modifier is sodium carbonate, with a total dosage of 800-1000 g / t; the depressant is water glass, with a total dosage of 2000-3000 g / t; and the collector is fatty acid soap, with a total dosage of 900-1200 g / t. The dosage of the reverse flotation reagents is relative to the dosage of the primary clay-type lithium ore in step S1.

[0018] Further optimization involves adding calcium chloride, sodium carbonate, water glass, and fatty acid soap sequentially to the overflow during the 1 roughing, 2 cleaning, and 2 scavenging open-circuit flotation process described in step S5. The roughing froth is then treated with water glass for the first cleaning, followed by a second cleaning with water glass. This second cleaning froth is the tailings 1. The material remaining in the tank after roughing is treated with fatty acid soap for the first scavenging, followed by a second scavenging with fatty acid soap. This second scavenging material is the lithium concentrate 1. The middlings from the 2 cleaning and 2 scavenging processes (first-stage middlings) are then combined and used as feed for the second stage flotation.

[0019] Further optimization, in step S5, the 1-roughing-2-scavenging open-circuit flotation refers to adding water glass and fatty acid soap to the middlings after 1-roughing-2-cleaning-2-scavenging for roughing; adding fatty acid soap to the material in the tank after roughing for the first scavenging; adding fatty acid soap to the material in the tank after the first scavenging for the second scavenging; and the tailings from the second scavenging are lithium concentrate 2. The middlings from 1-roughing-2-scavenging are then combined and used as feed for the third stage flotation.

[0020] Further optimization, in step S5, the 1 roughing 1 cleaning 1 scavenging closed-circuit flotation refers to adding water glass and fatty acid soap to the middlings after 1 roughing 2 scavenging open-circuit flotation for roughing, adding water glass to the roughing foam for cleaning, adding fatty acid soap to the material in the tank after roughing for scavenging, and returning the cleaned and scavenged middlings in sequence to form a closed circuit. The cleaned foam is tailings 2, and the material in the tank after scavenging is lithium concentrate 3.

[0021] Further preferred, the fatty acid soap in step S6 is sodium fatty acid.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. Graded disposal to reduce processing volume. Clay lithium ore is mainly found in easily mud-forming lithium chlorite. Primary clay lithium ore is in the form of lumps. After crushing, the clay minerals are not fully liberated. In addition to soaking and stirring, grinding is also required. The lithium content in the coarse particles after grinding is significantly reduced and can be directly disposed of as waste.

[0024] 2. Three-stage reverse flotation ensures lithium concentrate grade and recovery rate. In three-stage reverse flotation, separate processing of middlings effectively reduces the impact of middlings recycling on concentrate quality, which is beneficial to improving lithium concentrate grade. Multiple reverse flotation stages of middlings maximize the recovery of valuable components in the concentrate, avoiding lithium loss.

[0025] 3. Co-floating of silicon and calcium simplifies the reagent formulation. In conventional processes, decalcification is usually performed before desiliconization. Calcium generally refers to calcium carbonate, and silicon generally refers to silicon dioxide. The reagent systems for these two are relatively independent. In this invention, calcium chloride is used to activate quartz, achieving co-floating of silicon and calcium, effectively solving the problem of complex reagent formulations in a dual-system approach. Attached Figure Description

[0026] Figure 1 The above are process flow diagrams for embodiments 1-5 of the present invention. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are considered to be commercially available materials and reagents that can be obtained through conventional markets and other commercial channels.

[0028] In the following embodiments, the total amount of reagents (water glass or sodium fatty acid) is set according to a mass ratio of 3:1:1 for the first stage flotation: second stage flotation: first stage flotation. The first stage flotation process is 1 rougher, 2 cleaner, 2 scavenger open-circuit flotation, with a mass ratio of sodium fatty acid in the rougher, first scavenger, and second scavenger flotation of 3:1:1, and a mass ratio of water glass in the rougher, first cleaner, and second cleaner flotation of 3:1:1. The second stage flotation process is to combine the middlings from the first stage and perform 1 rougher and 2 scavenger open-circuit flotation, with a mass ratio of sodium fatty acid in the rougher, first scavenger, and second scavenger flotation of 3:1:1. The third stage flotation process is to perform 1 rougher, 1 cleaner, and 1 scavenger closed-circuit flotation on the middlings from the second stage, with a mass ratio of sodium fatty acid in the rougher and scavenger flotation of 3:1, and a mass ratio of water glass in the rougher and cleaner flotation of 3:1.

[0029] The open-circuit flotation process, consisting of 1 rougher, 2 cleaner, and 2 scavenger flotation stages, involves sequentially adding calcium chloride, sodium carbonate, water glass, and fatty acid soap to the overflow for roughing. The resulting froth is then added to water glass for the first cleaning stage, followed by a second cleaning stage. This second cleaning froth is the tailings 1. The remaining material in the tank after roughing is then added to fatty acid soap for the first scavenging stage, followed by a second scavenging stage. This second scavenging material is the lithium concentrate 1. The middlings from the 2 cleaner and 2 scavenger flotation stages (first stage middlings) are combined and used as feed for the second stage flotation.

[0030] The 1-roughing-2-scavenging open-circuit flotation process involves adding water glass and fatty acid soap to the middlings after the 1-roughing-2-cleaning-2-scavenging process for roughing. The material remaining in the tank after roughing is then added to fatty acid soap for the first scavenging, followed by a second scavenging with fatty acid soap. The tailings from the second scavenging are lithium concentrate 2. The middlings from the 1-roughing-2-scavenging process are combined and used as feed for the third stage of flotation.

[0031] The 1-rough-1-clean-1-scaveng closed-circuit flotation process refers to the process where, after the open-circuit flotation of 1 rough and 2 scaveng, the middlings are added to water glass and fatty acid soap for roughing, the roughing foam is added to water glass for cleaning, and the material in the tank after roughing is added to fatty acid soap for scavenging. The middlings from the cleaning and scavenging processes are returned sequentially to form a closed circuit. The cleaning foam is the tailings 2, and the material in the tank after scavenging is lithium concentrate 3.

[0032] In the following examples, the collector fatty acid soap is preferably sodium fatty acid.

[0033] Example 1

[0034] Reference Figure 1 A beneficiation method for enriching and recovering lithium from primary clay-type lithium ore, specifically including the following steps:

[0035] S1. The primary clay-type lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0036] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 30%, and place it in a mixing tank. Soak and stir thoroughly at a stirring speed of 1200 rpm for 60 minutes.

[0037] S3. The stirred slurry is classified into 0.1mm particles and coarsely ground to -0.1mm.

[0038] S4. Classify the graded grinding product to a particle size of 0.025mm to obtain underflow and overflow.

[0039] S5. The overflow is subjected to slurry conditioning and reverse flotation for impurity removal. The reverse flotation adopts a three-stage flotation process. The first stage flotation process is 1 roughing, 2 cleaning, and 2 scavenging open-circuit flotation. The second stage flotation process is to combine the middlings from the first stage and perform 1 roughing and 2 scavenging open-circuit flotation. The third stage flotation process is to perform 1 roughing, 1 cleaning, and 1 scavenging closed-circuit flotation on the middlings from the second stage. The reverse flotation activator is calcium chloride, with a total dosage of 200 g / t; the conditioning agent is sodium carbonate, with a total dosage of 1000 g / t; the depressant is water glass, with a total dosage of 3000 g / t; and the collector is sodium fatty acid, with a total dosage of 1200 g / t.

[0040] The products from the reverse flotation operation are combined into a comprehensive lithium concentrate.

[0041] Recovery rate calculation formula:

[0042]

[0043] Wherein, ε represents the Li2O recovery rate of the concentrate; a, b, and c represent the Li2O grade of the raw ore, concentrate, and tailings, respectively.

[0044] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.91% and a recovery rate of 66.58% can be obtained from a primary lithium clay ore in a certain area of ​​Guizhou with a raw ore containing 0.56% Li2O.

[0045] Example 2

[0046] Reference Figure 1 A beneficiation method for enriching and recovering lithium from primary clay-type lithium ore, specifically including the following steps:

[0047] S1. The primary clay-type lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0048] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 30%, and place it in a mixing tank. Soak and stir thoroughly at a stirring speed of 800 rpm for 30 minutes.

[0049] S3. The stirred slurry is classified into 0.1mm particles and coarsely ground to -0.1mm.

[0050] S4. Classify the graded grinding product to a particle size of 0.025mm to obtain underflow and overflow.

[0051] S5. The overflow is subjected to slurry conditioning and reverse flotation for impurity removal. The reverse flotation adopts a three-stage flotation process. The first stage flotation process is 1 roughing, 2 cleaning, and 2 scavenging open-circuit flotation. The second stage flotation process is to combine the middlings from the first stage and perform 1 roughing and 2 scavenging open-circuit flotation. The third stage flotation process is to perform 1 roughing, 1 cleaning, and 1 scavenging closed-circuit flotation on the middlings from the second stage. The reverse flotation activator is calcium chloride, with a total dosage of 200 g / t; the conditioning agent is sodium carbonate, with a total dosage of 800 g / t; the depressant is water glass, with a total dosage of 2000 g / t; and the collector is sodium fatty acid, with a total dosage of 1200 g / t.

[0052] The products from the reverse flotation operation are combined into a comprehensive lithium concentrate.

[0053] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.82% and a recovery rate of 68.34% can be obtained from a primary lithium clay ore in a certain area of ​​Guizhou with a raw ore containing 0.55% Li2O.

[0054] Example 3

[0055] Reference Figure 1 A beneficiation method for enriching and recovering lithium from primary clay-type lithium ore, specifically including the following steps:

[0056] S1. The primary clay-type lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0057] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 40%, and place it in a mixing tank. Soak and stir it thoroughly at a stirring speed of 800 rpm for 60 minutes.

[0058] S3. The stirred slurry is classified into 0.1mm particles and coarsely ground to -0.1mm.

[0059] S4. Classify the graded grinding product to a particle size of 0.025mm to obtain underflow and overflow.

[0060] S5. The overflow is subjected to slurry conditioning and reverse flotation for impurity removal. The reverse flotation adopts a three-stage flotation process. The first stage flotation process is 1 roughing, 2 cleaning, and 2 scavenging open-circuit flotation. The second stage flotation process is to combine the middlings from the first stage and perform 1 roughing and 2 scavenging open-circuit flotation. The third stage flotation process is to perform 1 roughing, 1 cleaning, and 1 scavenging closed-circuit flotation on the middlings from the second stage. The reverse flotation activator is calcium chloride, with a total dosage of 100 g / t; the conditioning agent is sodium carbonate, with a total dosage of 1000 g / t; the depressant is water glass, with a total dosage of 3000 g / t; and the collector is sodium fatty acid, with a total dosage of 900 g / t.

[0061] The products from the reverse flotation operation are combined into a comprehensive lithium concentrate.

[0062] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.82% and a recovery rate of 69.25% can be obtained from a primary lithium clay ore in a certain area of ​​Guizhou with a raw ore containing 0.54% Li2O.

[0063] Example 4

[0064] Reference Figure 1 A beneficiation method for enriching and recovering lithium from primary clay-type lithium ore, specifically including the following steps:

[0065] S1. The primary clay-type lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0066] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 40%, and place it in a mixing tank. Soak and stir thoroughly at a stirring speed of 800 rpm for 50 minutes.

[0067] S3. The stirred slurry is classified into 0.1mm particles and coarsely ground to -0.1mm.

[0068] S4. Classify the graded grinding product to a particle size of 0.045mm to obtain underflow and overflow.

[0069] S5. The overflow is subjected to slurry conditioning and reverse flotation for impurity removal. The reverse flotation adopts a three-stage flotation process. The first stage flotation process is 1 roughing, 2 cleaning, and 2 scavenging open-circuit flotation. The second stage flotation process is to combine the middlings from the first stage and perform 1 roughing and 2 scavenging open-circuit flotation. The third stage flotation process is to perform 1 roughing, 1 cleaning, and 1 scavenging closed-circuit flotation on the middlings from the second stage. The reverse flotation activator is calcium chloride, with a total dosage of 100 g / t; the conditioning agent is sodium carbonate, with a total dosage of 1000 g / t; the depressant is water glass, with a total dosage of 2000 g / t; and the collector is sodium fatty acid, with a total dosage of 1200 g / t.

[0070] The products from the reverse flotation operation are combined into a comprehensive lithium concentrate.

[0071] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.83% and a recovery rate of 70.68% can be obtained from a primary lithium clay ore in a certain area of ​​Guizhou with a raw ore containing 0.54% Li2O.

[0072] Example 5

[0073] Reference Figure 1 A beneficiation method for enriching and recovering lithium from primary clay-type lithium ore, specifically including the following steps:

[0074] S1. The primary clay-type lithium ore is crushed to -2mm using a jaw crusher and a double roller mill.

[0075] S2. Add water to the crushed ore to make a slurry with an ore mass concentration of 30%, and place it in a mixing tank. Soak and stir thoroughly at a stirring speed of 800 rpm for 30 minutes.

[0076] S3. The stirred slurry is classified into 0.1mm particles and coarsely ground to -0.1mm.

[0077] S4. Classify the graded grinding product to a particle size of 0.045mm to obtain underflow and overflow.

[0078] S5. The overflow is subjected to slurry conditioning and reverse flotation for impurity removal. The reverse flotation adopts a three-stage flotation process. The first stage flotation process is 1 roughing, 2 cleaning, and 2 scavenging open-circuit flotation. The second stage flotation process is to combine the middlings from the first stage and perform 1 roughing and 2 scavenging open-circuit flotation. The third stage flotation process is to perform 1 roughing, 1 cleaning, and 1 scavenging closed-circuit flotation on the middlings from the second stage. The reverse flotation activator is calcium chloride, with a total dosage of 100 g / t; the conditioning agent is sodium carbonate, with a total dosage of 800 g / t; the depressant is water glass, with a total dosage of 2000 g / t; and the collector is sodium fatty acid, with a total dosage of 900 g / t.

[0079] The products from the reverse flotation operation are combined into a comprehensive lithium concentrate.

[0080] Using the above process, a comprehensive lithium concentrate with a Li2O content of 0.84% ​​and a recovery rate of 71.26% can be obtained from a primary lithium clay ore in a certain area of ​​Guizhou with a raw ore containing 0.55% Li2O.

[0081] Comparative Example 1

[0082] A method for enriching lithium, the specific process is as follows:

[0083] S1. Crush the clay lithium ore to -2mm, wet ball mill for 5min, until the -0.045mm content is above 90%;

[0084] S2. After grinding, the product is slurried to a mass concentration of 30% and then subjected to reverse flotation to remove impurities. The process is 1 coarse, 1 scaveng, and 2 fine, and then returned to the closed circuit.

[0085] S3. In the roughing process, 2000g / t of sodium carbonate, 2000g / t of water glass, and 1000g / t of sodium fatty acid are added sequentially. In the scavenging process, 400g / t of sodium fatty acid is added. In the finer process 1, 500g / t of water glass is added. In the finer process 2, 500g / t of water glass is added.

[0086] The product from the flotation cell is used as a comprehensive lithium concentrate.

[0087] Using the above process, a primary lithium clay ore in a certain area of ​​Guizhou Province, containing 0.54% Li₂O in its raw ore, can yield a comprehensive lithium concentrate with a Li₂O content of 0.65% and a recovery rate of 72.50%. However, in processing this clay-lithium ore, fine-grained clay continuously accumulates and interferes with flotation during the closed-circuit cycle, while quartz gangue is not efficiently removed, resulting in low impurity removal efficiency and difficulty in improving the Li₂O grade of the lithium concentrate.

[0088] Comparative Example 2

[0089] A method for enriching lithium, the specific process is as follows:

[0090] S1. Crush the clay lithium ore to -2mm, wet ball mill for 5min, until the -0.045mm content is above 90%;

[0091] S2. The product after grinding is slurryed to a mass concentration of 30% and then subjected to decalcification flotation. The process is: 1 roughing, 1 scavenging, 2 cleaning, and then returned to the closed circuit. In the roughing stage, 2000 g / t of sodium carbonate, 2000 g / t of water glass, and 1000 g / t of sodium fatty acid are added sequentially. In the scavenging stage, 400 g / t of sodium fatty acid is added. In the cleaning stage 1, 500 g / t of water glass is added. In the cleaning stage 2, 500 g / t of water glass is added.

[0092] S3. The decalcified product is subjected to desiliconization flotation, with the process being: 1. Roughing, 1. Scavenging, 2. Cleaning, and then returned to the closed circuit. In the roughing stage, 500 g / t of sodium carbonate, 500 g / t of water glass, and 150 g / t of ether amine are added sequentially. In the scavenging stage, 400 g / t of sodium fatty acid is added. In the cleaning stage 1, 500 g / t of water glass is added. In the cleaning stage 2, 500 g / t of water glass is added.

[0093] S3 foam products are used as lithium concentrate.

[0094] Using the above process, a primary lithium clay ore in a certain area of ​​Guizhou Province, containing 0.54% Li₂O in its raw ore, can yield a comprehensive lithium concentrate with a Li₂O content of 0.81% and a recovery rate of 56.38%. This method employs two reagent systems when processing clay-lithium ore: reverse flotation for decalcification followed by forward flotation for lithium floating. However, during the forward flotation process, the collector's floatability for fine-grained clay is insufficient, making it difficult to improve the Li₂O recovery rate of the lithium concentrate.

[0095] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A beneficiation method for enriching and recovering lithium from a primary clay-type lithium mine, characterized by, It comprises the following steps: S1, crushing the primary clay type lithium ore to below 2 mm; S2, adding water to the crushed ore to make a pulp with a mass concentration of 30-40%, and placing it in a stirring container for full immersion and stirring; S3, grading the stirred pulp to 0.1 mm, and grinding the coarse particles to below 0.1 mm; S4, grading the ground product obtained in step S3 to obtain sand and overflow; S5, performing reverse flotation on the overflow, wherein the reverse flotation adopts a three-stage flotation process, the first-stage flotation process is 1 roughing-2 cleaning-2 scavenging open-circuit flotation, the second-stage flotation process is 1 roughing-2 scavenging open-circuit flotation on the middlings of the first stage, and the third-stage flotation process is 1 roughing-1 cleaning-1 scavenging closed-circuit flotation on the middlings of the second stage, and the in-tank product of the reverse flotation operation is combined as lithium concentrate; The activator of the reverse flotation is calcium chloride, the total dosage is 100-200 g / t; the regulator is sodium carbonate, the total dosage is 800-1000 g / t; the depressant is water glass, the total dosage is 2000-3000 g / t; The collector is fatty acid soap, the total dosage is 900-1200 g / t, and the dosages of the reverse flotation reagents are all relative to the dosage of the primary clay type lithium ore in step S1; the 1 roughing-2 cleaning-2 scavenging open-circuit flotation refers to adding calcium chloride, sodium carbonate, water glass and fatty acid soap in sequence to the overflow for roughing, adding water glass to the foam after roughing for first cleaning, adding water glass to the foam after the first cleaning for second cleaning, and the second cleaning foam being tailings 1; adding fatty acid soap to the in-tank material after roughing for first scavenging, adding fatty acid soap to the in-tank material after the first scavenging for second scavenging, and the in-tank material after the second scavenging being lithium concentrate 1.

2. The beneficiation method according to claim 1, characterized in that, The primary clay type lithium ore in step S1 is bottom primary ore, and the Li2O content is 0.5-0.6%.

3. The beneficiation method according to claim 1 or 2, c h a r a c t e r i z e d in that, The immersion and stirring conditions in step S2 are as follows: the immersion and stirring speed is 800-1200 rpm, and the immersion and stirring time is 30-60 min.

4. The beneficiation method according to claim 1 or 2, characterized in that, The grading size in step S4 is 0.025-0.045 mm.

5. The beneficiation method according to claim 1, characterized in that, The 1 roughing-2 scavenging open-circuit flotation in step S5 refers to adding water glass and fatty acid soap to the middlings after 1 roughing-2 cleaning-2 scavenging for roughing, adding fatty acid soap to the in-tank material after roughing for first scavenging, adding fatty acid soap to the in-tank material after the first scavenging for second scavenging, and the second scavenging tailings being lithium concentrate 2.

6. The beneficiation method according to claim 1, characterized in that, The 1 roughing-1 cleaning-1 scavenging closed-circuit flotation in step S5 refers to adding water glass and fatty acid soap to the middlings after 1 roughing-2 scavenging open-circuit flotation for roughing, adding water glass to the foam after roughing for cleaning, adding fatty acid soap to the in-tank material after roughing for scavenging, and the cleaning and scavenging middlings returning in sequence to form a closed circuit, the foam after cleaning being tailings 2, and the in-tank material after scavenging being lithium concentrate 3.

7. The beneficiation method according to claim 1, 5 or 6, characterized in that, The fatty acid soap in step S5 is sodium fatty acid.

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