A method of beneficiating lithium from a clay lithium ore

Abstract

The present application relates to the technical field of mineral processing, and particularly provides a method for enriching lithium in clay lithium ore by mineral processing. The method comprises the following steps: (1) preparing ore pulp; (2) ultrasonic pretreatment; (3) gravity separation; (4) first reverse flotation; (5) second reverse flotation; and (6) combination. The present application uses specific collectors and depressants, greatly improves the content and recovery rate of Li2O and lithium chlorite in the obtained lithium concentrate, and reduces the content of illite and kaolinite, thus having unexpected technical effects.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and specifically to a method for enriching lithium in clay lithium ore. Background Technology

[0002] In recent years, the rapid development of new energy vehicles, energy storage, and other fields has led to a rapid increase in global demand for lithium resources. Currently, lithium supply mainly comes from hard-rock lithium mines and salt lake brines. However, my country's lithium extraction from hard-rock lithium mines is primarily reliant on imports, while salt lake brines face significant development challenges due to harsh conditions and natural environments. In contrast, lithium-rich clay is easier to mine and readily available. Its development and utilization would significantly enhance my country's lithium resource security.

[0003] Compared to foreign Jadar lithium deposits, domestic clay-type lithium ores have lower Li2O grades, making direct lithium extraction using metallurgical methods such as roasting with additives followed by water leaching or acid leaching costly. Therefore, beneficiation enrichment of clay-type lithium resources is crucial for their development and utilization. In China's Yunnan-Guizhou region, the main minerals in clay-type lithium ores are layered silicate minerals such as illite or kaolinite and lithium chlorite, accounting for 70-90%. The remainder contains small amounts of diaspore, anatase, quartz, calcite, and pyrite. Lithium chlorite is the primary lithium-bearing mineral, closely intercalated with gangue minerals such as illite and kaolinite. These minerals are prone to mud formation and, being layered silicate minerals with similar physicochemical properties, are difficult to effectively separate through beneficiation methods. Currently, research on the separation of silicate minerals from clay-type lithium ores is limited. Therefore, the key to achieving lithium enrichment from clay-type lithium ores lies in the effective separation of these silicate minerals.

[0004] Chinese patent application CN116727100A discloses a method for beneficiating low-grade clay lithium ore. This method enriches lithium through steps such as classification, reverse flotation desilication, and magnetic separation to remove iron. During desilication, amine cationic collectors are used, and inhibitors are polysaccharide collectors such as sodium silicate, sodium hexametaphosphate, and starch. Activators include sodium chloride, sodium fluoride, and sodium fluorosilicate. However, the collectors and inhibitors are not selective for layered silicate minerals, and the activators cannot selectively activate the inhibited silicate minerals, resulting in poor separation effect.

[0005] Chinese patent application CN117144151A discloses a method for enriching clay lithium ore. This method enriches lithium through steps such as gravity separation and chemical beneficiation. Gravity separation can separate minerals with high density such as diaspore, anatase, and pyrite. Chemical beneficiation can dissolve some metal elements such as Fe, Ca, and Mg adsorbed between the layers of layered silicate minerals, but it cannot separate silicate minerals.

[0006] Therefore, there is still an urgent need for a lithium enrichment method in clay lithium ores with good selectivity, good separation effect, and good lithium enrichment effect. Summary of the Invention

[0007] To address the aforementioned technical problems, the present invention provides the following technical solutions.

[0008] In a first aspect, the present invention provides a method for enriching lithium in clay lithium ore.

[0009] A method for enriching lithium in clay lithium ore, comprising the following steps:

[0010] (1) Slurry preparation: Clay lithium ore is crushed, ground and classified to obtain slurry;

[0011] (2) Ultrasonic pretreatment: The slurry obtained in step (1) is subjected to ultrasonic pretreatment and classified to obtain coarse slurry with a particle size ≥10μm and fine slurry with a particle size less than 10μm.

[0012] (3) Gravity separation: The coarse-grained slurry with a particle size ≥10μm obtained in step (2) is subjected to gravity separation to obtain heavy tailings and light concentrate slurry;

[0013] (4) First reverse flotation: After adjusting the pH of the light concentrate slurry obtained in step (3), reverse flotation is performed to obtain foam 1 and concentrate slurry 1;

[0014] (5) Second reverse flotation: After adjusting the pH of concentrate slurry 1 obtained in step (4), a second reverse flotation is performed to obtain foam 2 and concentrate slurry 2;

[0015] (6) Merging: Merge the concentrate slurry 2 obtained in step (5) and the fine-grained slurry with a particle size of less than 10 μm obtained in step (2) to obtain lithium concentrate.

[0016] In some embodiments, the first reverse flotation includes: adjusting the pH of the light concentrate pulp obtained in step (3) and then performing any one of the following sets of operations:

[0017] (4-i) The first roughing process yields froth 1-a and concentrate slurry 1-a; the resulting concentrate slurry 1-a is then used as concentrate slurry 1 for the second reverse flotation in step (5); or

[0018] (4-ii) First roughing, pH adjustment, and then fine selection 1; wherein, after the first roughing, froth 1-a and concentrate slurry 1-a are obtained; the pH of the obtained concentrate slurry 1-a is adjusted, and then fine selection 1 is performed to obtain froth 1-b and concentrate slurry 1-b; the obtained concentrate slurry 1-b is used as the concentrate slurry 1 for the second reverse flotation in step (5); optionally, the obtained froth 1-b is returned to the first roughing in step (4-ii); or

[0019] (4-iii) First roughing, pH adjustment, then fine selection 1, pH adjustment again, then fine selection 2; wherein, after the first roughing, foam 1-a and concentrate slurry 1-a are obtained; adjust the pH of the obtained concentrate slurry 1-a, then fine selection 1 is performed to obtain foam 1-b and concentrate slurry 1-b; adjust the pH of the obtained concentrate slurry 1-b, then fine selection 2 is performed to obtain foam 1-c and concentrate slurry 1-c; the obtained concentrate slurry 1-c is used as the concentrate slurry 1 for the second reverse flotation in step (5); optionally, the obtained foam 1-b is returned to the first roughing in step (4-iii); optionally, the obtained foam 1-c is returned to the fine selection 1 in step (4-iii).

[0020] In some embodiments, the second reverse flotation step (5) includes: adjusting the pH of the concentrate slurry 1 obtained in step (4) and then performing any one of the following sets of operations:

[0021] (5-i) The second roughing process yields foam 2-a and concentrate slurry 2-a, wherein concentrate slurry 2-a is the concentrate slurry 2; or

[0022] (5-ii) Second roughing, pH adjustment, followed by fine-tuning 3; wherein, after the second roughing, foam 2-a and concentrate slurry 2-a are obtained; the pH of the obtained concentrate slurry 2-a is adjusted, followed by fine-tuning 3, to obtain foam 2-b and concentrate slurry 2-b, wherein concentrate slurry 2-b is the concentrate slurry 2; optionally, the obtained foam 2-b is returned to the second roughing in step (5-ii); or

[0023] (5-iii) Second roughing, pH adjustment, then fine selection 3, pH adjustment again, then fine selection 4; wherein, after the second roughing, foam 2-a and concentrate slurry 2-a are obtained; adjust the pH of the obtained concentrate slurry 2-a, then fine selection 3 is performed to obtain foam 2-b and concentrate slurry 2-b; adjust the pH of the obtained concentrate slurry 2-b, then fine selection 4 is performed to obtain foam 2-c and concentrate slurry 2-c, wherein concentrate slurry 2-c is the concentrate slurry 2; optionally, the obtained foam 2-b is returned to the second roughing in step (5-iii); optionally, the obtained foam 2-c is returned to the fine selection in step (5-iii) 3.

[0024] In some embodiments, the first roughing in the first reverse flotation includes: adding inhibitor 1 and collector 1 in sequence and then performing flotation skimming.

[0025] In some embodiments, the selection 1 of the first reverse flotation selection (4-ii) includes: not adding any more reagents, stirring and adjusting the slurry, and flotation skimming.

[0026] In some embodiments, the first reverse flotation (4-iii) selection 1 includes: adding inhibitor 1 and collector 1 in sequence and then performing flotation skimming.

[0027] In some embodiments, the selection 2 of the first reverse flotation (4-iii) includes: not adding any more reagents, stirring and adjusting the slurry, and flotation skimming.

[0028] In some embodiments, the first roughing stage of the second reverse flotation includes: sequentially adding inhibitor 2, collector 2 and modifier, followed by flotation skimming.

[0029] In some embodiments, the selection 3 of the second reverse flotation (5-ii) includes: not adding any more reagents, stirring and adjusting the slurry, and flotation skimming.

[0030] In some embodiments, the selection 3 in the second reverse flotation (5-iii) includes: adding inhibitor 2, collector 2 and modifier in sequence and then performing flotation skimming.

[0031] In some embodiments, the selection 4 of the second reverse flotation (5-iii) includes: not adding any more reagents, stirring and adjusting the slurry, and flotation skimming.

[0032] In some embodiments, the inhibitor 1 includes at least one of sodium polystyrene sulfonate, sodium polyacrylate, and ammonium polyacrylate.

[0033] In some embodiments, the weight-average molecular weight of inhibitor 1 is 10,000 g / mol to 50,000 g / mol. In some embodiments, the weight-average molecular weight of inhibitor 1 is 10,000 g / mol, 15,000 g / mol, 20,000 g / mol, 25,000 g / mol, 30,000 g / mol, 35,000 g / mol, 40,000 g / mol, 45,000 g / mol, or 50,000 g / mol.

[0034] In some embodiments, the sodium polystyrene sulfonate has a weight-average molecular weight of 40,000 g / mol to 50,000 g / mol. In some embodiments, the sodium polystyrene sulfonate has a weight-average molecular weight of 40,000 g / mol, 45,000 g / mol, or 50,000 g / mol.

[0035] In some embodiments, the sodium polyacrylate or ammonium polyacrylate has a weight-average molecular weight of 10,000 g / mol to 20,000 g / mol. In some embodiments, the sodium polyacrylate or ammonium polyacrylate has a weight-average molecular weight of 10,000 g / mol, 15,000 g / mol, or 20,000 g / mol.

[0036] In some embodiments, during the first roughing process, 0.3 mg to 4 mg of the inhibitor 1 is added per 1 L of light concentrate pulp. In some embodiments, during the first roughing process, 0.3 mg, 0.5 mg, 1 mg, 1.5 mg, 2 mg, 2.5 mg, 3 mg, 3.5 mg, or 4 mg of the inhibitor 1 is added per 1 L of light concentrate pulp.

[0037] In some embodiments, in the selected concentrate 1 of the first reverse flotation (4-iii), 0.3 mg to 4 mg of the inhibitor 1 is added per 1 L of concentrate 1-a. In some embodiments, in the selected concentrate 1 of the first reverse flotation (4-iii), 0.3 mg, 0.5 mg, 1 mg, 1.5 mg, 2 mg, 2.5 mg, 3 mg, 3.5 mg, or 4 mg of the inhibitor 1 is added per 1 L of concentrate 1-a.

[0038] In some embodiments, the collector 1 comprises sodium tetraphenylborate (C 24 H 20 BNa).

[0039] In some embodiments, during the first roughing process, 24 mg to 140 mg of collector 1 is added per 1 L of light concentrate pulp. In some embodiments, during the first roughing process, 24 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, or 140 mg of collector 1 is added per 1 L of light concentrate pulp.

[0040] In some embodiments, in the first reverse flotation (4-iii) finer concentrate 1, 24 mg to 140 mg of collector 1 is added per 1 L of concentrate 1-a. In some embodiments, in the first reverse flotation (4-iii) finer concentrate 1, 24 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, or 140 mg of collector 1 is added per 1 L of concentrate 1-a.

[0041] In some embodiments, the inhibitor 2 includes at least one of aluminum chloride, aluminum sulfate, or aluminum nitrate.

[0042] In some embodiments, during the second coarse selection, 0.6 mg to 2.1 mg of inhibitor 2 is added per 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c. In some embodiments, during the second coarse selection, 0.6 mg, 0.7 mg, 0.8 mg, 0.9 mg, 1.0 mg, 1.1 mg, 1.2 mg, 1.3 mg, 1.4 mg, 1.5 mg, 1.6 mg, 1.7 mg, 1.8 mg, 1.9 mg, 2.0 mg, or 2.1 mg of inhibitor 2 is added per 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c.

[0043] In some embodiments, in the refined 3 of the second reverse flotation (5-iii), 0.5 mg to 2.1 mg of inhibitor 2 is added per 1 L of concentrate 2-a. In some embodiments, in the refined 3 of the second reverse flotation (5-iii), 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, 0.9 mg, 1.0 mg, 1.1 mg, 1.2 mg, 1.3 mg, 1.4 mg, 1.5 mg, 1.6 mg, 1.7 mg, 1.8 mg, 1.9 mg, 2.0 mg, or 2.1 mg of inhibitor 2 is added per 1 L of concentrate 2-a.

[0044] In some embodiments, the collector 2 comprises an amine cationic collector.

[0045] In some embodiments, the collector 2 comprises aliphatic amine cationic collectors.

[0046] In some embodiments, the collector 2 comprises at least one of dodecylamine, hexadecylamine, octadecylamine, hexadecyltrimethylammonium chloride, and hexadecyltrimethylammonium bromide.

[0047] In some embodiments, during the second roughing process, 0.5 mg to 1.5 mg of the collector 2 is added per 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c. In some embodiments, during the second roughing process, 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, 0.9 mg, 1.0 mg, 1.1 mg, 1.2 mg, 1.3 mg, 1.4 mg, or 1.5 mg of the collector 2 is added per 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c.

[0048] In some embodiments, in the refined stage 3 of the second reverse flotation (5-iii), 0.5 mg to 1.5 mg of the collector 2 is added per 1 L of concentrate 2-a. In some embodiments, in the refined stage 3 of the second reverse flotation (5-iii), 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, 0.9 mg, 1.0 mg, 1.1 mg, 1.2 mg, 1.3 mg, 1.4 mg, or 1.5 mg of the collector 2 is added per 1 L of concentrate 2-a.

[0049] In some embodiments, the modifier includes acetic acid.

[0050] In some embodiments, during the second roughing process, 0.05 mg to 0.3 mg of the modifier is added per 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c. In some embodiments, during the second roughing process, 0.05 mg, 0.06 mg, 0.07 mg, 0.08 mg, 0.09 mg, 0.1 mg, 0.15 mg, 0.2 mg, 0.25 mg, or 0.3 mg of the modifier is added per 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c.

[0051] In some embodiments, in the refined 3 of the second reverse flotation (5-iii) process, 0.05 mg to 0.3 mg of the modifier is added per 1 L of concentrate 2-a. In some embodiments, in the refined 3 of the second reverse flotation (5-iii) process, 0.05 mg, 0.06 mg, 0.07 mg, 0.08 mg, 0.09 mg, 0.1 mg, 0.15 mg, 0.2 mg, 0.25 mg, or 0.3 mg of the modifier is added per 1 L of concentrate 2-a.

[0052] In some embodiments, the pH of the light concentrate slurry of the first reverse flotation, the pH of concentrate slurry 1-a, the pH of concentrate slurry 1-b, the pH of concentrate slurry 1 of the second reverse flotation, the pH of concentrate slurry 2-a, and the pH of concentrate slurry 2-b are each adjusted independently using at least one selected from NaOH aqueous solution, HCl, and HCl aqueous solution.

[0053] In some embodiments, the pH of the light concentrate slurry of the first reverse flotation, the pH of concentrate slurry 1-a, and the pH of concentrate slurry 1-b are each independently adjusted to 5 to 7. In some embodiments, the pH of the light concentrate slurry of the first reverse flotation, the pH of concentrate slurry 1-a, and the pH of concentrate slurry 1-b are each independently adjusted to 5, 5.5, 6, 6.5, or 7.

[0054] In some embodiments, the pH of concentrate slurry 1, concentrate slurry 2-a, and concentrate slurry 2-b in the second reverse flotation are each independently adjusted to 3 to 4. In some embodiments, the pH of concentrate slurry 1, concentrate slurry 2-a, and concentrate slurry 2-b in the second reverse flotation are each independently adjusted to 3, 3.5, or 4.

[0055] In some embodiments, the D90 of the solid particles in the slurry obtained in step (1) is less than or equal to 0.074 mm.

[0056] In some embodiments, the concentration of solids in the slurry obtained in step (1) is 10 wt%-30 wt%. In some embodiments, the concentration of solids in the slurry obtained in step (1) is 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt%.

[0057] In some embodiments, the ultrasonic power in step (2) is 60W to 300W. In some embodiments, the ultrasonic power in step (2) is 60W, 70W, 80W, 90W, 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W, 200W, 210W, 220W, 230W, 240W, 250W, 260W, 270W, 280W, 290W, or 300W.

[0058] In some embodiments, the ultrasound time in step (2) is 5 min to 30 min. In some embodiments, the ultrasound time in step (2) is 5 min, 10 min, 15 min, 20 min, 25 min or 30 min.

[0059] In some embodiments, the reselection in step (3) is performed at a rotational speed of 600 r / min to 900 r / min. In some embodiments, the reselection in step (3) is performed at a rotational speed of 600 r / min, 650 r / min, 700 r / min, 750 r / min, 800 r / min, 850 r / min or 900 r / min.

[0060] In some embodiments, the reselection time in step (3) is 5 min to 15 min. In some embodiments, the reselection time in step (3) is 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min or 15 min.

[0061] In some embodiments, the foam 1-a obtained from the first coarse selection contains illite.

[0062] In some embodiments, the illite content in the dried product of foam 1-a obtained from the first roughing is 80 wt%-90 wt%. In some embodiments, the illite content in the dried product of foam 1-a obtained from the first roughing is 80 wt%, 81 wt%, 82 wt%, 83 wt%, 84 wt%, 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, or 90 wt%.

[0063] In some embodiments, the foam 2-a obtained from the second coarse selection contains kaolinite.

[0064] In some embodiments, the kaolinite content in the dried product of foam 2-a obtained from the second roughing process is 85wt%-95wt%. In some embodiments, the kaolinite content in the dried product of foam 2-a obtained from the second roughing process is 85wt%, 86wt%, 87wt%, 88wt%, 89wt%, 90wt%, 91wt%, 92wt%, 93wt%, 94wt%, or 95wt%.

[0065] The method provided in the first aspect is used to prepare lithium concentrate. The resulting lithium concentrate has high Li2O and lithium chlorite content and recovery rate, low illite and kaolinite content, and high illite and kaolinite removal rate, which has excellent unexpected technical effects.

[0066] Secondly, the present invention provides a lithium concentrate prepared by the aforementioned method.

[0067] A lithium concentrate prepared according to the method described in the first aspect.

[0068] Beneficial effects

[0069] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0070] 1. This invention inhibits the flotation of lithium chlorite by adding inhibitors such as sodium polystyrene sulfonate or sodium polyacrylate, and then adds sodium tetraphenylborate for reverse flotation to selectively collect illite, thereby obtaining illite concentrate. This achieves effective separation of illite from silicate minerals such as lithium chlorite and kaolinite, which is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite. It is also more conducive to reducing the content of illite and kaolinite in lithium concentrate, which has unexpected technical effects.

[0071] 2. The surface potential of lithium chlorite is adjusted by adding inhibitors such as aluminum chloride, aluminum sulfate or aluminum nitrate, and then amine cationic collectors are added for reverse flotation to selectively collect kaolinite, thereby obtaining kaolinite concentrate and lithium chlorite concentrate, and finally achieving effective separation of lithium chlorite from silicate minerals.

[0072] 3. In step (4), compared with other collectors (such as dodecylamine, dodecylaminoacetic acid or sodium oleate), the collector 1 (sodium tetraphenylborate) provided by the present invention is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, which has unexpected technical effects.

[0073] 4. In step (4), compared with other inhibitors (such as oxalic acid, water glass or carboxymethyl starch), the inhibitor 1 provided by the present invention (such as at least one of sodium polystyrene sulfonate, sodium polyacrylate, and ammonium polyacrylate) is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, which has unexpected technical effects.

[0074] 5. In step (5), compared with other collectors (such as dodecylaminoacetic acid, sodium oleate or C10 etheramine), the collector 2 provided by the present invention (such as at least one of dodecylamine, hexadecylamine, octadecylamine, hexadecyltrimethylammonium chloride and hexadecyltrimethylammonium bromide) is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, with unexpected technical effects.

[0075] 6. In step (5), compared with other inhibitors (such as calcium chloride, sodium hexametaphosphate or formamide), the inhibitor 2 provided by this invention (such as at least one of aluminum chloride, aluminum sulfate or aluminum nitrate) is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, with unexpected technical effects.

[0076] 7. The lithium concentrate prepared by the method provided in this invention has high Li2O and lithium chlorite content and recovery rate, low illite and kaolinite content, and high illite and kaolinite removal rate, and has excellent unexpected technical effects.

[0077] Terminology Explanation

[0078] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0079] The term “room temperature” refers to ambient temperature, which is between approximately 10°C and approximately 30°C, or approximately 20°C and approximately 30°C, or approximately 25°C.

[0080] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0081] In the following content, all figures disclosed herein, whether or not they use words such as "approximately" or "about," are approximate values. The value of each figure may vary by 1%, 2%, 5%, 7%, 8%, 10%, 15%, or 20%, etc. Whenever a figure with a value of N is disclosed, any figure with a value of N+ / -1%, N+ / -2%, N+ / -3%, N+ / -5%, N+ / -7%, N+ / -8%, N+ / -10%, N+ / -15%, or N+ / -20% will be explicitly disclosed, where "+ / -" indicates addition or subtraction.

[0082] Heavy tailings: mainly composed of denser minerals, primarily gibbsite, anatase, and pyrite. Centrifugal concentrators are devices that utilize centrifugal force to enhance the separation of mineral particles by density, especially suitable for separating fine-grained minerals (e.g., smaller than 0.074 mm). Their core principle is to use the centrifugal force field generated by high-speed rotation to replace the traditional gravity field, accelerating the stratification and separation of particles with density differences. The slurry enters the inner wall of the high-speed rotating concentrator through the feed pipe, forming an annular slurry layer under the action of centrifugal force. High-density particles (such as metallic minerals) experience greater centrifugal force, adhere tightly to the outer wall of the concentrator, and settle downwards, being discharged intermittently or continuously through the discharge port to obtain heavy tailings.

[0083] Light concentrate slurry: mainly composed of minerals with relatively low density, primarily silicate minerals such as lithium chlorite, kaolinite, and illite. The slurry enters the inner wall of a high-speed rotating sorting cone through the feed pipe, where it adheres tightly to the cone wall under centrifugal force, forming an annular slurry layer. Low-density particles (such as gangue) have low centrifugal force, are closer to the inner layer of the sorting cone, and move with the water flow towards the overflow end, exiting from the overflow port at the top of the sorting cone, thus obtaining the light concentrate slurry.

[0084] Li2O enrichment ratio = Li2O grade in concentrate ÷ Li2O grade in raw ore Detailed Implementation

[0085] To enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting embodiments are further disclosed below to provide a more detailed description of the present invention.

[0086] The reagents or consumables used in this invention can be purchased from the market or prepared by the methods described in this invention.

[0087] Unless otherwise specified, the reagents used in the embodiments of the present invention are:

[0088] Sodium polystyrene sulfonate has a weight-average molecular weight of 50,000 g / mol.

[0089] Sodium polyacrylate has a weight-average molecular weight of 10,000 g / mol.

[0090] The weight-average molecular weight of ammonium polyacrylate is 10,000 g / mol.

[0091] Example 1: One roughing and two cleaning reverse flotation (first reverse flotation) + one roughing and reverse flotation (second reverse flotation)

[0092] The following beneficiation process was carried out on a clay lithium ore deposit in a certain area of ​​Guizhou Province with a Li₂O grade of 0.86%, lithium chlorite content of 26.47%, illite content of 54.48%, and kaolinite content of 8.61%:

[0093] Step (1): Crush and ball mill the clay lithium ore to obtain a grinding slurry with a particle size of less than 0.074 mm accounting for 90%;

[0094] Step (2): The grinding slurry was pretreated by ultrasonic stirring tank with an ultrasonic power of 100W and an ultrasonic time of 10min, and the solid mass concentration in the grinding slurry was controlled to be 12wt%. Then, it was classified to obtain coarse slurry with a particle size ≥10μm and fine slurry with a particle size <10μm.

[0095] Step (3): Use a centrifugal concentrator to perform gravity separation on coarse-grained slurry with a particle size ≥10μm. The separation cone speed is 600r / min and the separation time is 6min to obtain heavy tailings and light concentrate slurry.

[0096] Step (4): The light concentrate slurry undergoes a first roughing and second cleaning reverse flotation:

[0097] First roughing: Adjust the pH of the light concentrate slurry obtained in step (3) to 5 with HCl aqueous solution or NaOH aqueous solution, then add sodium polystyrene sulfonate at a ratio of 3 mg per 1 L of light concentrate slurry (inhibitor 1), stir and adjust the slurry for 3 min, then add sodium tetraphenylborate at a ratio of 120 mg per 1 L of light concentrate slurry (collector 1), stir and adjust the slurry for 3 min, and perform flotation and skimming for 5 min to obtain foam 1-a and concentrate slurry 1-a. The foam 1-a is illite tailings, and the bottom product is concentrate slurry 1-a.

[0098] Selected 1: Adjust the pH of the concentrate slurry 1-a obtained from the first roughing to 5 with HCl aqueous solution or NaOH aqueous solution, then add sodium polystyrene sulfonate at a ratio of 0.3 mg per 1 L of concentrate slurry 1-a, stir and adjust the slurry for 3 min, then add sodium tetraphenylborate at a ratio of 30 mg per 1 L of concentrate slurry 1-a, stir and adjust the slurry for 3 min, and perform flotation and skimming for 4 min to obtain foam 1-b and concentrate slurry 1-b. The bottom product is concentrate slurry 1-b. Foam 1-b is returned and combined with the light concentrate slurry obtained in step (3) for the first roughing.

[0099] Selection 2: Adjust the pH of concentrate slurry 1-b obtained from selection 1 to 5 with HCl aqueous solution or NaOH aqueous solution, then stir and adjust the slurry for 1 min, and then float and scrape the foam for 2 min to obtain foam 1-c and concentrate slurry 1-c. The product at the bottom of the tank is concentrate slurry 1-c; foam 1-c is returned and combined with concentrate slurry 1-a obtained from the first roughing to carry out selection 1.

[0100] Step (5): The concentrate pulp is subjected to one more roughing and reverse flotation:

[0101] Second roughing: Adjust the pH of the concentrate slurry 1-c obtained in step (4) to 4 with HCl aqueous solution or NaOH aqueous solution, then add AlCl3 at a ratio of 1.3 mg AlCl3 (inhibitor 2) per 1 L concentrate slurry 1-c, stir and adjust the slurry for 2 min, then add hexadecylamine (collector 2) and 0.05 mg acetic acid (adjuster) per 1 L concentrate slurry 1-c, stir and adjust the slurry for 2 min, and perform flotation and skimming for 3 min to obtain froth 2-a and concentrate slurry 2-a; froth 2-a is kaolinite tailings, and the bottom product is concentrate slurry 2-a. Concentrate slurry 2-a and the fine-grained slurry with a particle size of less than 10 μm obtained in step (2) are combined to form lithium concentrate.

[0102] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1.

[0103] Example 2: One roughing reverse flotation (first reverse flotation) + one roughing and two cleaning reverse flotation (second reverse flotation)

[0104] The following beneficiation process was carried out on a clay lithium ore from a certain area in Guizhou Province, with a Li₂O grade of 0.87%, lithium chlorite content of 26.87%, illite content of 10.45%, and kaolinite content of 51.16%:

[0105] Step (1): Crush and ball mill the clay lithium ore to obtain a grinding slurry with a particle size of less than 0.074 mm accounting for 90%;

[0106] Step (2): The grinding slurry was pretreated by ultrasonic stirring in an ultrasonic tank with an ultrasonic power of 150W and an ultrasonic time of 15min, and the solid mass concentration in the grinding slurry was controlled to be 15wt%. Then, it was classified to obtain coarse slurry with a particle size ≥10μm and fine slurry with a particle size <10μm.

[0107] Step (3): The coarse-grained slurry with a particle size ≥10μm obtained in step (2) is subjected to gravity separation using a centrifugal concentrator with a separation cone speed of 650r / min and a separation time of 8min to obtain heavy tailings and light concentrate slurry.

[0108] Step (4): Perform a roughing reverse flotation on the light concentrate pulp obtained in step (3):

[0109] First roughing: Adjust the pH of the light concentrate slurry obtained in step (3) to 7 with HCl aqueous solution or NaOH aqueous solution, then add sodium polystyrene sulfonate at a ratio of 3 mg per 1 L of light concentrate slurry (inhibitor 1), stir and adjust the slurry for 3 min, then add sodium tetraphenylborate at a ratio of 50 mg per 1 L of light concentrate slurry (collector 1), stir and adjust the slurry for 1 min, and perform flotation and skimming for 4 min to obtain foam 1-a and concentrate slurry 1-a. The foam 1-a is illite tailings, and the bottom product is concentrate slurry 1-a.

[0110] Step (5): Perform reverse flotation (roughing and cleaning) on ​​the concentrate slurry 1-a obtained in step (4):

[0111] Second roughing: Adjust the pH of the concentrate slurry 1-a obtained in step (4) to 3 with HCl aqueous solution or NaOH aqueous solution, then add AlCl3 at a ratio of 2.1 mg AlCl3 (inhibitor 2) per 1 L of concentrate slurry 1-a, stir and adjust the slurry for 5 min, then add dodecylamine and acetic acid at a ratio of 1.5 mg dodecylamine (collector 2) and 0.3 mg acetic acid (adjuster) per 1 L of concentrate slurry 1-a, stir and adjust the slurry for 4 min, and perform flotation and skimming for 5 min to obtain froth 2-a and concentrate slurry 2-a; froth 2-a is kaolinite tailings, and the bottom product is concentrate slurry 2-a;

[0112] Selected step 3: Adjust the pH of concentrate slurry 2-a to 3 with HCl aqueous solution or NaOH aqueous solution; then add AlCl3 at a ratio of 1.3 mg AlCl3 (inhibitor 2) per 1 L concentrate slurry 2-a, stir and adjust the slurry for 2 min, then add dodecylamine and acetic acid at a ratio of 0.5 mg dodecylamine (collector 2) and 0.1 mg acetic acid (adjuster) per 1 L concentrate slurry 2-a, stir and adjust the slurry for 2 min, and perform flotation and skimming for 4 min to obtain foam 2-b and concentrate slurry 2-b. Foam 2-b is returned to be combined with concentrate slurry 1-a obtained in step (4) for the second roughing, and the bottom product of the tank is concentrate slurry 2-b;

[0113] Selection 4: Adjust the pH of concentrate slurry 2-b to 3 with HCl aqueous solution or NaOH aqueous solution, then stir and adjust the slurry for 1 min, and perform flotation and skimming for 2 min to obtain foam 2-c and concentrate slurry 2-c. Foam 2-c is returned and combined with concentrate slurry 2-a for selection 3. The bottom product of the tank is concentrate slurry 2-c. Concentrate slurry 2-c is combined with fine-grained slurry with a particle size of less than 10 μm obtained in step (2) to form lithium concentrate.

[0114] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1.

[0115] Example 3: Roughing and Cleaning Reverse Flotation (First Reverse Flotation) + Roughing and Cleaning Reverse Flotation (Second Reverse Flotation)

[0116] The following beneficiation process was carried out on a clay lithium ore from a certain area in Guizhou Province, with a Li₂O grade of 0.84%, lithium chlorite content of 26.23%, illite content of 36.88%, and kaolinite content of 25.93%:

[0117] Step (1): Crush and ball mill the clay lithium ore to obtain a grinding slurry with a particle size of less than 0.074 mm accounting for 90%;

[0118] Step (2): The grinding slurry was pretreated by ultrasonic stirring in an ultrasonic tank with an ultrasonic power of 90W and an ultrasonic time of 20min, and the solid mass concentration in the grinding slurry was controlled to be 20wt%. Then, it was classified to obtain coarse-grained slurry with a particle size ≥10μm and fine-grained slurry with a particle size <10μm.

[0119] Step (3): Use a centrifugal concentrator to perform gravity separation on coarse-grained slurry with a particle size ≥10μm. The separation cone speed is 800r / min and the separation time is 15min to obtain heavy tailings and light concentrate slurry.

[0120] Step (4): The light concentrate slurry undergoes a roughing and cleaning reverse flotation:

[0121] First roughing: Adjust the pH of the light concentrate slurry obtained in step (3) to 6 with HCl aqueous solution or NaOH aqueous solution, then add sodium polystyrene sulfonate at a ratio of 3 mg per 1 L of light concentrate slurry (inhibitor 1), stir and adjust the slurry for 6 min, then add sodium tetraphenylborate at a ratio of 90 mg per 1 L of light concentrate slurry (collector 1), stir and adjust the slurry for 3 min, and perform flotation and skimming for 4 min to obtain foam 1-a and concentrate slurry 1-a. Foam 1-a is illite tailings, and the bottom product is concentrate slurry 1-a.

[0122] Selected 1: Adjust the pH of concentrate slurry 1-a to 6 with HCl aqueous solution or NaOH aqueous solution; then stir and adjust the slurry for 1 min, and perform flotation and skimming for 2 min to obtain foam 1-b and concentrate slurry 1-b; return foam 1-b to be combined with the light concentrate slurry obtained in step (3) for the first roughing, and the bottom product of the tank is concentrate slurry 1-b;

[0123] Step (5): The concentrate slurry continues to undergo reverse flotation of rougher and cleaner;

[0124] Second roughing: Adjust the pH of the concentrate slurry 1-b obtained in step (4) to 3 with HCl aqueous solution or NaOH aqueous solution, then add AlCl3 (inhibitor 2) at a ratio of 2.0 mg AlCl3 (inhibitor 2) per 1 L concentrate slurry 1-b, stir and adjust the slurry for 5 min, then add dodecylamine (collector 2) and acetic acid (adjuster) at a ratio of 1.4 mg dodecylamine (collector 2) and 0.25 mg acetic acid (adjuster) per 1 L concentrate slurry 1-b, stir and adjust the slurry for 4 min, and perform flotation and skimming for 5 min to obtain froth 2-a and concentrate slurry 2-a; froth 2-a is kaolinite tailings, and the bottom product is concentrate slurry 2-a;

[0125] Selected 3: Adjust the pH of concentrate slurry 2-a to 3 with HCl aqueous solution or NaOH aqueous solution, stir and adjust the slurry for 1 min, and perform flotation and skimming for 2 min to obtain foam 2-b and concentrate slurry 2-b; return foam 2-b to be combined with concentrate slurry 1-b obtained in step (4) for a second roughing, and the bottom product of the tank is concentrate slurry 2-b; combine concentrate slurry 2-b with fine-grained slurry with a particle size of less than 10 μm obtained in step (2) to form lithium concentrate.

[0126] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1.

[0127] Example 4: One roughing reverse flotation (first reverse flotation) + one roughing and two cleaning reverse flotation (second reverse flotation)

[0128] The following beneficiation process was carried out on a clay lithium ore deposit in a certain area of ​​Guizhou Province with a Li₂O grade of 0.73%, lithium chlorite content of 22.57%, illite content of 12.64%, and kaolinite content of 53.03%:

[0129] Step (1): Crush and ball mill the clay lithium ore to obtain a grinding slurry with a particle size of less than 0.074 mm accounting for 90%;

[0130] Step (2): The grinding slurry was pretreated by ultrasonic stirring in an ultrasonic tank with an ultrasonic power of 100W and an ultrasonic time of 24min, and the solid mass concentration in the grinding slurry was controlled to be 25wt%. Then, it was classified to obtain coarse slurry with a particle size ≥10μm and fine slurry with a particle size <10μm.

[0131] Step (3): Use a centrifugal concentrator to perform gravity separation on coarse-grained slurry with a particle size ≥10μm. The separation cone speed is 850r / min and the separation time is 15min to obtain heavy tailings and light concentrate slurry.

[0132] Step (4): The light concentrate slurry undergoes a roughing and reverse flotation:

[0133] First roughing: Adjust the pH of the light concentrate slurry obtained in step (3) to 7 with HCl aqueous solution or NaOH aqueous solution, then add sodium polyacrylate at a ratio of 2.6 mg sodium polyacrylate (inhibitor 1) per 1 L of light concentrate slurry, stir and adjust the slurry for 3 min, then add sodium tetraphenylborate at a ratio of 50 mg sodium tetraphenylborate (collector 1) per 1 L of light concentrate slurry, stir and adjust the slurry for 3 min, and perform flotation and skimming for 4 min to obtain foam 1-a and concentrate slurry 1-a. Foam 1-a is illite tailings, and the bottom product is concentrate slurry 1-a.

[0134] Step (5): The concentrate slurry continues to undergo reverse flotation of roughing and cleaning:

[0135] Second roughing: Adjust the pH of the concentrate slurry 1-a obtained in step (4) to 3 with HCl aqueous solution or NaOH aqueous solution, then add Al2(SO4)2 at a ratio of 2.0 mg Al2(SO4)2 (inhibitor 2) per 1 L concentrate slurry 1-a, stir and adjust the slurry for 5 min, then add octadecylamine (collector 2) at a ratio of 1.5 mg octadecylamine (collector 2) and 0.3 mg acetic acid (adjuster) per 1 L concentrate slurry 1-a, stir and adjust the slurry for 4 min, and flotation and skim the foam for 5 min to obtain foam 2-a and concentrate slurry 2-a. Foam 2-a is kaolinite tailings, and the bottom product is concentrate slurry 2-a.

[0136] Selected 3: Adjust the pH of the concentrate slurry 2-a obtained in step (4) to 3 with HCl aqueous solution or NaOH aqueous solution, then add Al2(SO4)2 at a ratio of 1 mg Al2(SO4)2 (inhibitor 2) per 1 L concentrate slurry 2-a, stir and adjust the slurry for 3 min, then add 0.5 mg octadecylamine (collector 2) and 0.1 mg acetic acid (adjuster) per 1 L concentrate slurry 2-a, stir and adjust the slurry for 3 min, and perform flotation and skimming for 4 min to obtain foam 2-b and concentrate slurry 2-b. Foam 2-b is returned to be combined with concentrate slurry 1-a obtained in step (4) and then subjected to a second roughing process. The bottom product of the tank is concentrate slurry 2-b.

[0137] Selection 4: Adjust the pH of the obtained concentrate slurry 2-b to 3 with HCl aqueous solution or NaOH aqueous solution, then do not add any reagents, stir and adjust the slurry for 1 min, and flotation and skim the foam for 2 min to obtain foam 2-c and concentrate slurry 2-c. Foam 2-c is returned and combined with concentrate slurry 2-a obtained in step (4) for selection 3. The bottom product of the tank is concentrate slurry 2-c. Concentrate slurry 2-c is combined with fine-grained slurry with a particle size of less than 10 μm obtained in step (2) to form lithium concentrate.

[0138] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1.

[0139] Example 5: Roughing and Cleaning Reverse Flotation (First Reverse Flotation) + Roughing and Cleaning Reverse Flotation (Second Reverse Flotation)

[0140] The following beneficiation process was carried out on a clay lithium ore from a certain area in Guizhou Province, with a Li₂O grade of 0.60%, lithium chlorite content of 18.47%, illite content of 41.54%, and kaolinite content of 28.76%:

[0141] Step (1): Crush and ball mill the clay lithium ore to obtain a grinding slurry with a particle size of less than 0.074 mm accounting for 90%.

[0142] Step (2): The grinding slurry was pretreated by ultrasonic stirring tank with an ultrasonic power of 200W and an ultrasonic time of 30min, and the solid mass concentration in the grinding slurry was controlled to be 18wt%. Then, it was classified to obtain coarse slurry with a particle size ≥10μm and fine slurry with a particle size <10μm.

[0143] Step (3): Use a centrifugal concentrator to perform gravity separation on coarse-grained slurry with a particle size ≥10μm. The separation cone speed is 900r / min and the separation time is 14min to obtain heavy tailings and light concentrate slurry.

[0144] Step (4): Perform reverse flotation (roughing and cleaning) on ​​the light concentrate slurry obtained in step (3):

[0145] First roughing: Adjust the pH of the light concentrate slurry obtained in step (3) to 5 with HCl aqueous solution or NaOH aqueous solution, then add sodium polyacrylate at a ratio of 2.5 mg sodium polyacrylate (inhibitor 1) per 1 L of light concentrate slurry, stir and adjust the slurry for 3 min, then add sodium tetraphenylborate at a ratio of 100 mg sodium tetraphenylborate (collector 1) per 1 L of light concentrate slurry, stir and adjust the slurry for 3 min, and perform flotation and skimming for 4 min to obtain foam 1-a and concentrate slurry 1-a. Foam 1-a is illite tailings, and the bottom product is concentrate slurry 1-a.

[0146] Selected 1: Adjust the pH of concentrate slurry 1-a to 5 with HCl aqueous solution or NaOH aqueous solution, then add sodium polyacrylate at a ratio of 0.5 mg sodium polyacrylate (inhibitor 1) per 1 L concentrate slurry 1-a, stir and adjust the slurry for 3 min, then add sodium tetraphenylborate at a ratio of 30 mg sodium tetraphenylborate (collector 1) per 1 L concentrate slurry 1-a, stir and adjust the slurry for 3 min, and perform flotation and skimming for 3 min to obtain foam 1-b and concentrate slurry 1-b; return foam 1-b to be combined with the light concentrate slurry obtained in step (3) for the first roughing, and the bottom product of the tank is concentrate slurry 1-b;

[0147] Selection 2: Adjust the pH of concentrate slurry 1-b to 5 with HCl aqueous solution or NaOH aqueous solution, then do not add any reagents, stir and adjust the slurry for 1 min, and perform flotation and skimming for 2 min to obtain froth 1-c and concentrate slurry 1-c. The product at the bottom of the tank is concentrate slurry 1-c; froth 1-c is returned and combined with concentrate slurry 1-a for selection 1.

[0148] Step (5): The obtained concentrate slurry 1-c is subjected to a rougher-cleaner reverse flotation:

[0149] Second roughing: Adjust the pH of the concentrate slurry 1-c obtained in step (4) to 3 with HCl aqueous solution or NaOH aqueous solution, then add Al2(SO4)2 at a ratio of 1.8 mg Al2(SO4)2 (inhibitor 2) per 1 L concentrate slurry 1-c, stir and adjust the slurry for 5 min, then add hexadecyltrimethylammonium chloride and acetic acid at a ratio of 1.3 mg hexadecyltrimethylammonium chloride (collector 2) and 0.2 mg acetic acid (adjuster) per 1 L concentrate slurry 1-c, stir and adjust the slurry for 4 min, and flotation and skim the foam for 5 min to obtain foam 2-a and concentrate slurry 2-a. Foam 2-a is kaolinite tailings, and the bottom product is concentrate slurry 2-a.

[0150] Selected 3: Adjust the pH of concentrate slurry 2-a to 3 with HCl aqueous solution or NaOH aqueous solution, without adding any reagents, stir and adjust the slurry for 1 min, and perform flotation and skimming for 2 min to obtain foam 2-b and concentrate slurry 2-b. Foam 2-b is returned and combined with concentrate slurry 1-c obtained in step (4) for a second roughing process. The bottom product of the tank is concentrate slurry 2-b. Concentrate slurry 2-b and fine-grained slurry with a particle size of less than 10 μm obtained in step (2) are combined to form lithium concentrate.

[0151] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1.

[0152] Example 6: One rougher-one cleaner reverse flotation (first reverse flotation) + one rougher-two cleaner reverse flotation (second reverse flotation)

[0153] The following beneficiation process was carried out on a clay lithium ore from a certain area in Guizhou Province, with a Li₂O grade of 0.47%, lithium chlorite content of 14.16%, illite content of 32.53%, and kaolinite content of 40.34%:

[0154] Step (1): Crush and ball mill the clay lithium ore to obtain a grinding slurry with a particle size of less than 0.074 mm accounting for 90%.

[0155] Step (2): The grinding slurry was pretreated by ultrasonic stirring tank with an ultrasonic power of 300W and an ultrasonic time of 6min, and the solid mass concentration in the grinding slurry was controlled to be 12wt%. Then, it was classified to obtain coarse slurry with a particle size ≥10μm and fine slurry with a particle size <10μm.

[0156] Step (3): Use a centrifugal concentrator to perform gravity separation on coarse-grained slurry with a particle size ≥10μm. The separation cone speed is 900r / min and the separation time is 6min to obtain heavy tailings and light concentrate slurry.

[0157] Step (4): The light concentrate slurry undergoes a roughing and cleaning reverse flotation:

[0158] First roughing: Adjust the pH of the light concentrate slurry obtained in step (3) to 5 with HCl aqueous solution or NaOH aqueous solution, then add 2.0 mg of ammonium polyacrylate (inhibitor 1) per 1 L of light concentrate slurry, stir and adjust the slurry for 3 min, then add 80 mg of sodium tetraphenylborate (collector 1) per 1 L of light concentrate slurry, stir and adjust the slurry for 3 min, and flotation and skim the foam for 4 min to obtain foam 1-a and concentrate slurry 1-a. Foam 1-a is illite tailings, and the bottom product is concentrate slurry 1-a.

[0159] Selected 1: Adjust the pH of concentrate slurry 1-a to 5 with HCl aqueous solution or NaOH aqueous solution, then do not add any reagents, stir and adjust the slurry for 1 min, and flotation and skim the bubbles for 2 min to obtain foam 1-b and concentrate slurry 1-b. Foam 1-b is returned and combined with the light concentrate slurry obtained in step (3) for the first roughing. The bottom product of the tank is concentrate slurry 1-b.

[0160] Step (5): Continue the reverse flotation of the concentrate slurry 1-b, first roughing and second cleaning:

[0161] Second roughing: Adjust the pH of the concentrate slurry 1-b obtained in step (4) to 3 with HCl aqueous solution or NaOH aqueous solution, then add Al(NO3)3 at a ratio of 2.0 mg Al(NO3)3 (inhibitor 2) per 1 L concentrate slurry 1-b, stir and adjust the slurry for 5 min, then add hexadecyltrimethylammonium bromide and acetic acid at a ratio of 1.2 mg hexadecyltrimethylammonium bromide (collector 2) and 0.15 mg acetic acid (adjuster) per 1 L concentrate slurry 1-b, stir and adjust the slurry for 4 min, and flotation and skim the foam for 5 min to obtain foam 2-a and concentrate slurry 2-a. Foam 2-a is kaolinite tailings, and the bottom product is concentrate slurry 2-a.

[0162] Selected step 3: Adjust the pH of concentrate slurry 2-a to 3 with HCl aqueous solution or NaOH aqueous solution; then add Al(NO3)3 at a ratio of 0.5 mg Al(NO3)3 (inhibitor 2) per 1 L concentrate slurry 2-a, stir and adjust the slurry for 3 min, then add octadecylamine and acetic acid at a ratio of 0.5 mg hexadecyltrimethylammonium bromide (collector 2) and 0.05 mg acetic acid (adjuster) per 1 L concentrate slurry 2-a, stir and adjust the slurry for 3 min, and perform flotation and skimming for 4 min to obtain foam 2-b and concentrate slurry 2-b. Foam 2-b is returned and combined with concentrate slurry 1-b obtained in step (4) for a second roughing process. The bottom product is concentrate slurry 2-b.

[0163] Selection 4: Adjust the pH of concentrate slurry 2-b to 3 with HCl or NaOH aqueous solution, then add no more reagents, stir and adjust the slurry for 1 min, and perform flotation and skimming for 2 min to obtain froth 2-c and concentrate slurry 2-c. Froth 2-c is returned and combined with concentrate slurry 2-a for selection 3. The bottom product is concentrate slurry 2-c. Concentrate slurry 2-c is combined with fine-grained slurry with a particle size of less than 10 μm to form lithium concentrate.

[0164] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1.

[0165] Comparative Example 1: Investigation of the collector 1 in step (4)

[0166] The following beneficiation process was performed on the same clay lithium ore as in Example 1:

[0167] The operation steps are the same as in Example 1, except that the sodium tetraphenylborate in the first roughing and cleaning steps in step (4) is replaced with dodecylamine of the same feed weight as before the replacement. That is, the phrase "add sodium tetraphenylborate at a ratio of 120 mg per 1 L of light concentrate slurry" in the first roughing step in step (4) is replaced with "add dodecylamine at a ratio of 120 mg per 1 L of light concentrate slurry" and the phrase "add 30 mg per 1 L of concentrate slurry" in the cleaning step in step (4) is replaced with "add dodecylamine at a ratio of 120 mg per 1 L of light concentrate slurry" and the phrase "add 30 mg per 1 L of concentrate slurry" in the cleaning step in step (4) is replaced with "add 30 mg per 1 L of concentrate slurry" and "add 30 mg per 1 L of light concentrate slurry" in the cleaning step in step (4). The phrase “add sodium tetraphenylborate (collector 1) at a ratio of 1 mg” is replaced with “add dodecylamine at a ratio of 30 mg dodecylamine (collector 1) per 1 L concentrate slurry 1-a” (similar expressions for other comparative examples below are similar). In the first roughing in step (4), when adding dodecylamine, acetic acid is added as a co-solvent at a ratio of 0.05 mg acetic acid per 1 L light concentrate slurry. In the fine selection 1 in step (4), when adding dodecylamine, acetic acid is added as a co-solvent at a ratio of 0.05 mg acetic acid per 1 L light concentrate slurry 1-a.

[0168] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results indicate that the dodecylamine collector has poor selectivity, resulting in low Li2O and lithium chlorite recovery rates. The improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less significant than in Examples 1-6 of this invention.

[0169] Comparative Example 2: Investigation of Collector 1 in Step (4)

[0170] The following beneficiation process was performed on the same clay lithium ore as in Example 5:

[0171] The operation steps are the same as in Example 5, except that the sodium tetraphenylborate in the first coarse selection and the first fine selection in step (4) is replaced with dodecylaminoacetic acid of the same feed mass as before the replacement.

[0172] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results indicate that the dodecylaminoacetic acid collector has poor selectivity, resulting in low Li2O and lithium chlorite recovery rates. The improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less significant than in Examples 1-6 of this invention.

[0173] Comparative Example 3: Investigation of Collector 1 in Step (4)

[0174] The following beneficiation process was performed on the same clay lithium ore as in Example 6:

[0175] The operation steps are the same as in Example 6, except that the sodium tetraphenylborate selected in the first coarse selection in step (4) is replaced with sodium oleate of the same feed mass as before the replacement.

[0176] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results indicate that sodium oleate collector has weak illite collecting ability and easily enters the concentrate, resulting in low Li2O and lithium chlorite recovery rates. The improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0177] Comparative Example 4: Examination of Inhibitor 1 in Step (4)

[0178] The following beneficiation process was performed on the same clay lithium ore as in Example 1:

[0179] The operation steps are the same as in Example 1, except that the sodium polystyrene sulfonate in the first coarse selection and the first fine selection in step (4) is replaced with oxalic acid of the same feed weight as before the replacement.

[0180] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results show that oxalic acid has a strong inhibitory effect on silicate minerals, leading to the entry of illite and kaolinite into the concentrate. The increase in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0181] Comparative Example 5: Examination of Inhibitor 1 in Step (4)

[0182] The following beneficiation process was performed on the same clay lithium ore as in Example 5:

[0183] The operation steps are the same as in Example 5, except that the sodium polyacrylate in the first coarse selection and the first fine selection in step (4) is replaced with water glass (sodium silicate) of the same feed mass as before the replacement.

[0184] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results show that water glass has a strong inhibitory effect on silicate minerals, leading to illite and kaolinite entering the concentrate. The increase in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0185] Comparative Example 6: Examination of Inhibitor 1 in Step (4)

[0186] The following beneficiation process was performed on the same clay lithium ore as in Example 6:

[0187] The operation steps are the same as in Example 6, except that the ammonium polyacrylate selected in the first coarse selection in step (4) is replaced with carboxymethyl starch of the same feed weight as before the replacement.

[0188] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results indicate that starch-based inhibitors tend to cause non-selective flocculation of silicate minerals, leading to the entry of illite and kaolinite into the concentrate. Therefore, the increase in Li2O and lithium chlorite content in the obtained lithium concentrate is far less significant than in Examples 1-6 of this invention.

[0189] Comparative Example 7: Investigation of Collector 2 in Step (5)

[0190] The following beneficiation process was performed on the same clay lithium ore as in Example 2:

[0191] The operation steps are the same as in Example 2, except that the dodecylamine in the second coarse selection and the fine selection in step (5) is replaced with dodecylaminoacetic acid of the same feed mass as before the replacement.

[0192] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results indicate that the dodecylaminoacetic acid collector has poor selectivity, resulting in low Li2O and lithium chlorite recovery rates. The improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less significant than in Examples 1-6 of this invention.

[0193] Comparative Example 8: Investigation of Collector 2 in Step (5)

[0194] The following beneficiation process was performed on the same clay lithium ore as in Example 5:

[0195] The operation steps are the same as in Example 5, except that the hexadecyltrimethylammonium chloride in the second coarse selection in step (5) is replaced with sodium oleate of the same feed mass as before the replacement.

[0196] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results indicate that sodium oleate collector has a certain collecting capacity for lithium chlorite, resulting in low Li2O and lithium chlorite recovery rates. The improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0197] Comparative Example 9: Investigation of Collector 2 in Step (5)

[0198] The following beneficiation process was performed on the same clay lithium ore as in Example 6:

[0199] The operation steps are the same as in Example 6, except that the cetyltrimethylammonium bromide in the second coarse selection and the fine selection in step (5) is replaced with C10 ether amine with the same feed mass as before the replacement.

[0200] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results indicate that the C10 etheramine collector has a certain collecting performance on lithium chlorite, resulting in low Li2O and lithium chlorite recovery rates. The improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0201] Comparative Example 10: Examination of Inhibitor 2 in Step (5)

[0202] The following beneficiation process was performed on the same clay lithium ore as in Example 2:

[0203] The operation steps are the same as in Example 2, except that the aluminum chloride (AlCl3) in the second coarse selection and the fine selection in step (5) is replaced with calcium chloride of the same feed mass as before the replacement.

[0204] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results show that calcium chloride adsorbs with sodium polystyrene sulfonate, activating the flotation performance of lithium chlorite, resulting in low Li2O and lithium chlorite recovery rates. Therefore, the improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0205] Comparative Example 11: Examination of Inhibitor 2 in Step (5)

[0206] The following beneficiation process was performed on the same clay lithium ore as in Example 5:

[0207] The operation steps are the same as in Example 5, except that the aluminum sulfate (Al2(SO4)2) selected in the second coarse selection in step (5) is replaced with sodium hexametaphosphate of the same feed mass as before the replacement.

[0208] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results show that sodium hexametaphosphate has an inhibitory effect on silicate minerals such as kaolinite and lithium chlorite, leading to kaolinite contamination of the concentrate. The recovery rates of Li2O and lithium chlorite are low, and the improvement in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0209] Comparative Example 12: Examination of Inhibitor 2 in Step (5)

[0210] The following beneficiation process was performed on the same clay lithium ore as in Example 6:

[0211] The operation steps are the same as in Example 6, except that the aluminum nitrate (Al(NO3)3) in the second coarse selection and the fine selection 3 in step (5) is replaced with formamide of the same feed mass as before the replacement.

[0212] The results of testing the Li2O grade (content), lithium chlorite content, Li2O recovery rate, and Li2O enrichment ratio in the obtained lithium concentrate are shown in Table 1. The results show that formamide and amine collectors compete with kaolinite for adsorption, leading to kaolinite contamination of the concentrate. Therefore, the increase in Li2O and lithium chlorite content in the obtained lithium concentrate is far less than that in Examples 1-6 of this invention.

[0213] Results summary: see Table 1.

[0214] Table 1: Summary of Results

[0215]

[0216]

[0217] Note: a: The recovery rates in Table 1 refer to the recovery rates of the corresponding components in lithium concentrate. Taking the recovery rate of Li2O in lithium concentrate as an example:

[0218] The recovery rate of Li2O in lithium concentrate (%) = (Li2O content in lithium concentrate × Lithium concentrate yield) ÷ (Li2O content in raw ore × Raw ore feed amount) × 100;

[0219] The recovery rates of other components follow the same principle. The recovery rates of other components can be calculated based on their respective contents in lithium concentrate and raw ore, as well as the value of (lithium concentrate yield ÷ raw ore feed amount). (The value of (lithium concentrate yield ÷ raw ore feed amount) can be converted based on the Li2O recovery rate in lithium concentrate or calculated based on the actual weighing results.)

[0220] To save space, the Li2O enrichment ratio is not listed separately, but can be calculated using the following formula:

[0221] Li2O enrichment ratio = Li2O grade in concentrate ÷ Li2O grade in raw ore

[0222] in conclusion:

[0223] 1. This invention inhibits the flotation of lithium chlorite by adding inhibitors such as sodium polystyrene sulfonate or sodium polyacrylate, and then adds sodium tetraphenylborate for reverse flotation to selectively collect illite, thereby obtaining illite concentrate. This achieves effective separation of illite from silicate minerals such as lithium chlorite and kaolinite, which is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite. It is also more conducive to reducing the content of illite and kaolinite in lithium concentrate, which has unexpected technical effects.

[0224] 2. The surface potential of lithium chlorite is adjusted by adding inhibitors such as aluminum chloride, aluminum sulfate or aluminum nitrate, and then amine cationic collectors are added for reverse flotation to selectively collect kaolinite, thereby obtaining kaolinite concentrate and lithium chlorite concentrate, and finally achieving effective separation of lithium chlorite from silicate minerals.

[0225] 3. In step (4), compared with other collectors (such as dodecylamine, dodecylaminoacetic acid or sodium oleate), the collector 1 (sodium tetraphenylborate) provided by the present invention is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, which has unexpected technical effects.

[0226] 4. In step (4), compared with other inhibitors (such as oxalic acid, water glass or carboxymethyl starch), the inhibitor 1 provided by the present invention (such as at least one of sodium polystyrene sulfonate, sodium polyacrylate, and ammonium polyacrylate) is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, which has unexpected technical effects.

[0227] 5. In step (5), compared with other collectors (such as dodecylaminoacetic acid, sodium oleate or C10 etheramine), the collector 2 provided by the present invention (such as at least one of dodecylamine, hexadecylamine, octadecylamine, hexadecyltrimethylammonium chloride and hexadecyltrimethylammonium bromide) is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, with unexpected technical effects.

[0228] 6. In step (5), compared with other inhibitors (such as calcium chloride, sodium hexametaphosphate or formamide), the inhibitor 2 provided by this invention (such as at least one of aluminum chloride, aluminum sulfate or aluminum nitrate) is more conducive to increasing the content of Li2O and lithium chlorite in lithium concentrate and the recovery rate of Li2O and lithium chlorite, and is more conducive to reducing the content of illite and kaolinite in lithium concentrate, with unexpected technical effects.

[0229] The method of this invention has been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and applications described herein within the scope, spirit, and context of this invention to implement and apply the technology of this invention. Those skilled in the art can refer to the content herein to appropriately improve process parameters. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of this invention.

Claims

1. A method for enriching lithium in clay lithium ore, characterized in that, Includes the following steps: (1) Slurry preparation: Clay lithium ore is crushed, ground and classified to obtain slurry; (2) Ultrasonic pretreatment: The slurry obtained in step (1) is subjected to ultrasonic pretreatment and classified to obtain coarse slurry with a particle size ≥10μm and fine slurry with a particle size less than 10μm. (3) Gravity separation: The coarse-grained slurry with a particle size ≥10μm obtained in step (2) is subjected to gravity separation to obtain heavy tailings and light concentrate slurry; (4) First reverse flotation: After adjusting the pH of the light concentrate slurry obtained in step (3), reverse flotation is performed to obtain foam 1 and concentrate slurry 1; (5) Second reverse flotation: After adjusting the pH of concentrate slurry 1 obtained in step (4), a second reverse flotation is performed to obtain foam 2 and concentrate slurry 2; (6) Merging: Merge the concentrate slurry 2 obtained in step (5) and the fine-grained slurry with a particle size of less than 10 μm obtained in step (2) to obtain lithium concentrate.

2. The method according to claim 1, wherein the first reverse flotation comprises: After adjusting the pH of the light concentrate slurry obtained in step (3), perform any one of the following operations: (4-i) The first roughing process yields froth 1-a and concentrate slurry 1-a; the resulting concentrate slurry 1-a is then used as concentrate slurry 1 for the second reverse flotation in step (5); or (4-ii) First roughing, pH adjustment, and then fine selection 1; wherein, after the first roughing, froth 1-a and concentrate slurry 1-a are obtained; the pH of the obtained concentrate slurry 1-a is adjusted, and then fine selection 1 is performed to obtain froth 1-b and concentrate slurry 1-b; the obtained concentrate slurry 1-b is used as the concentrate slurry 1 for the second reverse flotation in step (5); optionally, the obtained froth 1-b is returned to the first roughing in step (4-ii); or (4-iii) First roughing, pH adjustment, then fine selection 1, pH adjustment again, then fine selection 2; wherein, after the first roughing, foam 1-a and concentrate slurry 1-a are obtained; adjust the pH of the obtained concentrate slurry 1-a, then fine selection 1 is performed to obtain foam 1-b and concentrate slurry 1-b; adjust the pH of the obtained concentrate slurry 1-b, then fine selection 2 is performed to obtain foam 1-c and concentrate slurry 1-c; the obtained concentrate slurry 1-c is used as the concentrate slurry 1 for the second reverse flotation in step (5); optionally, the obtained foam 1-b is returned to the first roughing in step (4-iii); optionally, the obtained foam 1-c is returned to the fine selection 1 in step (4-iii).

3. The method according to any one of claims 1-2, wherein step (5) second reverse flotation comprises: After adjusting the pH of concentrate slurry 1 obtained in step (4), perform any one of the following operations: (5-i) The second roughing process yields foam 2-a and concentrate slurry 2-a, wherein concentrate slurry 2-a is the concentrate slurry 2; or (5-ii) Second roughing, pH adjustment, followed by fine-tuning 3; wherein, after the second roughing, foam 2-a and concentrate slurry 2-a are obtained; the pH of the obtained concentrate slurry 2-a is adjusted, followed by fine-tuning 3, to obtain foam 2-b and concentrate slurry 2-b, wherein concentrate slurry 2-b is the concentrate slurry 2; optionally, the obtained foam 2-b is returned to the second roughing in step (5-ii); or (5-iii) Second roughing, pH adjustment, then fine selection 3, pH adjustment again, then fine selection 4; wherein, after the second roughing, foam 2-a and concentrate slurry 2-a are obtained; the pH of the obtained concentrate slurry 2-a is adjusted, then fine selection 3 is performed, to obtain foam 2-b and concentrate slurry 2-b; the pH of the obtained concentrate slurry 2-b is adjusted, then fine selection 4 is performed, to obtain foam 2-c and concentrate slurry 2-c, wherein concentrate slurry 2-c is the concentrate slurry 2; optionally, the obtained foam 2-b is returned to the second roughing in step (5-iii); optionally, the obtained foam 2-c is returned to the fine selection in step (5-iii) 3.

4. The method according to any one of claims 2-3, wherein the first coarse selection in the first anti-float selection comprises: After adding inhibitor 1 and collector 1 in sequence, flotation and foam removal were performed. and / or The first reverse flotation selection (4-ii) includes: not adding any more reagents, stirring and conditioning the pulp, flotation skimming; and / or The first reverse flotation (4-iii) fine selection 1 includes: sequentially adding inhibitor 1 and collector 1 followed by flotation skimming; and / or The first reverse flotation (4-iii) fine selection 2 includes: without adding any more reagents, stirring and adjusting the slurry, and flotation skimming.

5. The method according to any one of claims 3-4, wherein the first roughing stage of the second reverse flotation comprises: After adding inhibitor 2, collector 2 and modifier in sequence, flotation and foam removal were performed. and / or The second reverse flotation (5-ii) fine selection 3 includes: no further addition of any reagents, stirring and conditioning the pulp, flotation skimming; and / or The second reverse flotation (5-iii) fine selection 3 includes: sequentially adding inhibitor 2, collector 2 and modifier followed by flotation skimming; and / or The second reverse flotation (5-iii) fine selection 4 includes: no further addition of any reagents, stirring and adjusting the pulp, and flotation skimming.

6. The method according to claim 4, wherein the inhibitor 1 comprises at least one of sodium polystyrene sulfonate, sodium polyacrylate, and ammonium polyacrylate; and / or The weight-average molecular weight of inhibitor 1 is 10,000 g / mol to 50,000 g / mol; and / or The sodium polystyrene sulfonate has a weight-average molecular weight of 40,000 g / mol to 50,000 g / mol; and / or The sodium polyacrylate has a weight-average molecular weight of 10,000 g / mol to 20,000 g / mol; and / or The ammonium polyacrylate has a weight-average molecular weight of 10,000 g / mol to 20,000 g / mol; and / or In the first roughing process, 0.3 mg to 4 mg of the inhibitor 1 is added to every 1 L of light concentrate pulp; and / or In the first reverse flotation (4-iii) fine selection 1, 0.3 mg to 4 mg of the inhibitor 1 is added per 1 L of concentrate 1-a; and / or The collector 1 comprises sodium tetraphenylborate; and / or In the first roughing stage, 24 mg to 140 mg of collector 1 is added to every 1 L of light concentrate pulp; and / or In the first reverse flotation (4-iii) fine selection 1, 24mg to 140mg of collector 1 is added per 1L of concentrate slurry 1-a.

7. The method according to claim 5, wherein the inhibitor 2 comprises at least one of aluminum chloride, aluminum sulfate, or aluminum nitrate; and / or In the second roughing process, 0.6 mg to 2.1 mg of inhibitor 2 is added to each 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c; and / or In the second reverse flotation (5-iii) finer step 3, 0.5 mg to 2.1 mg of inhibitor 2 is added per 1 L of concentrate 2-a; and / or The collector 2 includes amine cationic collectors; and / or The collector 2 includes aliphatic amine cationic collectors; and / or The collector 2 comprises at least one of dodecylamine, didodecylamine, hexadecylamine, octadecylamine, hexadecyltrimethylammonium chloride, and hexadecyltrimethylammonium bromide; and / or In the second roughing process, 0.5 mg to 1.5 mg of the collector 2 is added to every 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c; and / or In the second reverse flotation (5-iii) finesing 3, 0.5 mg to 1.5 mg of the collector 2 is added per 1 L of concentrate 2-a; and / or The modifier includes acetic acid; and / or In the second roughing process, 0.05 mg to 0.3 mg of the modifier is added to each 1 L of concentrate slurry 1, concentrate slurry 1-a, concentrate slurry 1-b, or concentrate slurry 1-c; and / or In the second reverse flotation (5-iii) fine selection 3, 0.05 mg to 0.3 mg of the modifier is added per 1 L of concentrate slurry 2-a.

8. The method according to any one of claims 2-7, wherein the pH of the light concentrate pulp of the first reverse flotation, the pH of concentrate pulp 1-a, the pH of concentrate pulp 1-b, the pH of concentrate pulp 1 of the second reverse flotation, the pH of concentrate pulp 2-a, and the pH of concentrate pulp 2-b are each independently adjusted by at least one selected from NaOH aqueous solution, HCl, and HCl aqueous solution; and / or The pH of the light concentrate pulp from the first reverse flotation, the pH of concentrate pulp 1-a, and the pH of concentrate pulp 1-b are each independently adjusted to 5-7; and / or The pH of concentrate slurry 1, concentrate slurry 2-a, and concentrate slurry 2-b from the second reverse flotation were independently adjusted to 3-4.

9. The method according to any one of claims 1-8, wherein the D90 of the solid particles in the slurry obtained in step (1) is less than or equal to 0.074 mm; and / or The concentration of solids in the slurry obtained in step (1) is 10wt%-30wt%; and / or The ultrasonic power in step (2) is 60W to 300W; and / or The ultrasound time in step (2) is 5 min to 30 min; and / or The reselection in step (3) is performed at a rotation speed of 600 r / min to 900 r / min; and / or The reselection time in step (3) is 5 min to 15 min.

10. A lithium concentrate prepared by the method according to any one of claims 1-9.

Images