A method of extracting lithium

Abstract

The embodiment of the present application provides a method for extracting lithium, comprising the following steps: mechanically activating lithium ore slurry to obtain activated slurry; then stirring and leaching the activated slurry under the action of an electric field; then performing solid-liquid separation to obtain a lithium-rich solution and leaching residue; the lithium ore slurry comprises beta-spodumene and alkali liquor, and the concentration of the alkali liquor is 4wt%-40wt%. In the step of extracting lithium in the present application, under the synergistic action of mechanical activation and an electric field, the lithium leaching efficiency of beta-spodumene is significantly improved under alkaline conditions. Moreover, the present application can be carried out at normal pressure and low temperature, and does not require non-standard equipment such as pressure vessels, special corrosion-resistant equipment, etc., and is easy to industrialize.

Description

Technical Field

[0001] This application relates to the field of metallurgy, and more specifically, to a method for extracting lithium. Background Technology

[0002] Lithium is an important energy metal, known as "white oil," and is widely used in the new energy field. Currently, my country's lithium resources are mainly concentrated in salt lake brines and lithium-bearing ores, with 80% distributed in salt lake brines. However, due to the high magnesium content in my country's salt lake brines, the cost of extracting lithium from the brines is high. Therefore, lithium extraction in my country mainly comes from lithium-bearing ores.

[0003] Lithium-bearing ores mainly include spodumene, lepidolite, and petalite, among which spodumene is the most widely used lithium extraction ore due to its high lithium content. Lithium extraction methods from spodumene mainly fall into two categories: pyrometallurgy and hydrometallurgy. Pyrometallurgy includes limestone roasting, sulfate processing, and chlorination roasting, but suffers from low lithium recovery rates and high energy consumption. Hydrometallurgy mainly includes the sulfate process and pressure leaching. The sulfate process generates a large amount of difficult-to-treat waste residue, while the pressure leaching method, although shorter in process, requires sodium carbonate pressure leaching and reaction at 200-250°C under high pressure, making the reaction conditions quite harsh.

[0004] Therefore, there is an urgent need to develop lithium extraction methods that have low equipment requirements, relatively low energy consumption, and simple process flow. Summary of the Invention

[0005] This application provides a method for extracting lithium. The extraction method of this application has mild reaction conditions and a high lithium leaching rate from spodumene, making it more suitable for large-scale applications.

[0006] The method for extracting lithium according to this application includes the following steps: mechanically activating lithium ore slurry to obtain activated slurry; then leaching the activated slurry after stirring under the action of an electric field; and then performing solid-liquid separation to obtain lithium-rich solution and leaching residue; the lithium ore slurry includes β-spodumene and alkaline solution, the concentration of which is 4wt%~40wt%.

[0007] In the above technical solution, when the lithium ore slurry is mechanically activated, the lithium-encapsulating layer (mainly aluminum, silicon, etc.) in β-spodumene is destroyed because the lithium ore slurry also contains 4% to 40% alkaline solution. Moreover, the lithium-containing mineral phase in β-spodumene will also undergo lattice distortion and dislocation, and the particle arrangement in the lattice will partially lose its periodicity, forming lattice defects. As a result, the internal energy of the β-spodumene lattice increases and the surface properties change, thus enhancing the reactivity of β-spodumene. When stirred under the action of an electric field, the electric field can cause lithium to migrate in spodumene, further enhancing the exchange of lithium ions with sodium or potassium ions. Through mechanical activation and the action of an electric field, the lithium ion leaching efficiency of β-spodumene is significantly increased. After leaching, solid-liquid separation is performed, and the resulting lithium-rich solution has a high concentration of lithium ions. The extraction method of this application achieves a good lithium-ion leaching rate without the need for pressurization, thus the reaction conditions are relatively mild; moreover, the extraction method of this application produces less leaching residue and basically no waste gas, which is also beneficial for subsequent treatment.

[0008] In one possible implementation, the current density of the electric field is greater than 0 and not greater than 100 mA / cm². 2 .

[0009] In one possible implementation, the current density of the electric field is 10~60 mA / cm². 2 .

[0010] In one possible implementation, the particle size of β-spodumene in the activated slurry is 15~83 μm.

[0011] In the above technical solution, when the particle size of β-spodumene in the activated slurry is 15~83μm, β-spodumene has good reactivity, which is beneficial to improving the leaching rate of lithium ions.

[0012] In one possible implementation, mechanical activation is performed using a ball mill, with a ball-to-material ratio of 10:1 to 35:1, a rotation speed of 200 to 600 rpm, and a time of 10 to 240 min.

[0013] In the above technical solutions, using a ball mill for mechanical activation is beneficial to improving production efficiency.

[0014] In one possible implementation, the ball-to-material ratio is 15:1 to 30:1, the rotation speed is 300 to 500 rpm, and the time is 30 to 150 min.

[0015] In one possible implementation, the liquid-to-solid ratio of alkali solution to β-spodumene in the lithium ore slurry is 1~15 ml / g.

[0016] In one possible implementation, the liquid-to-solid ratio of the alkali solution to β-spodumene is 4~12 ml / g.

[0017] In one possible implementation, the leaching step involves a leaching temperature of 60-120°C and a leaching time of 2-8 hours.

[0018] In the above technical solution, when the above conditions are met, the lithium ion leaching rate can be improved, and the production efficiency is also relatively high.

[0019] The beneficial effects of this application are:

[0020] This application provides a method for extracting lithium, comprising the following steps: mechanically activating a lithium ore slurry to obtain an activated slurry; then leaching the activated slurry after stirring under an electric field; followed by solid-liquid separation to obtain a lithium-rich solution and leaching residue; the lithium ore slurry includes β-spodumene and an alkaline solution, the concentration of which is 4wt%~40wt%. In this application, under the action of mechanical activation, the lithium-bearing mineral phase in spodumene undergoes lattice distortion and dislocation, and the particle arrangement in the lattice loses its periodicity, forming lattice defects, resulting in increased lattice internal energy, altered surface properties, and enhanced reactivity of β-spodumene; moreover, under the action of an electric field, lithium migrates in β-spodumene, further enhancing the exchange of lithium ions with sodium and potassium ions. Under alkaline conditions, the lithium leaching efficiency of β-spodumene is significantly improved under the synergistic effect of mechanical activation and an electric field. Moreover, this application can be carried out at normal pressure and low temperature, without the need for non-standard equipment such as pressure vessels and special corrosion-resistant equipment, making it easy for industrial production. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a process flow diagram in the embodiments of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0024] Currently, lithium extraction from lithium ore can be achieved using pyrometallurgical methods such as limestone roasting, sulfate processing, and chlorination roasting, or hydrometallurgical methods such as sulfuric acid processing and pressure leaching. However, pyrometallurgical methods suffer from low lithium recovery rates and high energy consumption; in hydrometallurgy, the sulfuric acid process generates a large amount of waste residue, which is environmentally unfriendly, while pressure leaching requires harsh reaction conditions under high pressure. Therefore, there is an urgent need to develop methods for lithium extraction that offer milder reaction conditions, higher extraction rates, and lower waste production.

[0025] To address the aforementioned technical problems, this application provides a method for extracting lithium, the details of which are described below.

[0026] The process flow diagram of the lithium extraction method of this application is as follows: Figure 1 As shown, it includes the following steps:

[0027] S100. Preparation of lithium ore slurry: Mix β-spodumene and alkaline solution to obtain lithium ore slurry.

[0028] In this step, after mixing β-spodumene with alkaline solution, the alkaline solution not only makes it easier to break the lithium-encapsulating layers (mainly aluminum, silicon, etc.) in β-spodumene, but also makes it easier for the chemical bonds in β-spodumene to break, thus making β-spodumene more easily activated and reacting.

[0029] In this step, the concentration of the alkali solution is 4wt%~40wt%, preferably 10wt%~30wt%; specifically, it can be 4wt%, 7wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, etc., or within any two of the above values. If the alkali solution concentration is too low, it will not effectively increase the activity of β-spodumene; if the alkali solution concentration is too high, it will increase the extraction cost and generate more waste residue. Furthermore, in this step, to ensure sufficient alkali solution to increase the activity of β-spodumene, the liquid-to-solid ratio of alkali solution to β-spodumene is generally 1~15ml / g, preferably 4~12ml / g, for example, it can be 1ml / g, 2.5ml / g, 4ml / g, 6ml / g, 8ml / g, 10ml / g, 12ml / g, 13.5ml / g, 15ml / g, etc., or within any two of the above values.

[0030] Furthermore, this application does not specifically limit the type of alkaline solution, as long as it meets the purpose of this application. For example, the alkaline solution can be sodium hydroxide solution and / or potassium hydroxide solution, etc.; as an example, in a specific embodiment of this application, the alkaline solution is sodium hydroxide solution.

[0031] S200. Mechanically activate the lithium ore slurry to obtain activated slurry.

[0032] In this step, due to the presence of alkaline solution, when the lithium ore slurry is mechanically activated, the lithium-containing mineral phase in β-spodumene will also undergo lattice distortion and dislocation. At the same time, the particle arrangement in the lattice will lose its periodicity and form lattice defects. As a result, the internal energy of the β-spodumene lattice increases and the surface properties change. Therefore, the reactivity of β-spodumene is enhanced, which is beneficial to the subsequent leaching of lithium ions from β-spodumene.

[0033] In some embodiments of this application, to improve production efficiency, this step is typically performed in a ball mill. The ball-to-material ratio during milling is 10:1 to 35:1, the rotation speed is 200 to 600 rpm, and the time is 10 to 240 minutes. The preferred ball-to-material ratio is 15:1 to 30:1, specifically 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, etc., or any two of the above values. The preferred rotation speed is 300 to 500 rpm, specifically 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, etc., or any two of the above values. The preferred time is 30 to 150 minutes, specifically 10 minutes, 30 minutes, 50 minutes, 80 minutes, 100 minutes, 120 minutes, 150 minutes, 180 minutes, 200 minutes, 240 minutes, etc. min, etc., or within a range consisting of any two of the above values.

[0034] In the activated slurry obtained in this step, the particle size of β-spodumene is 15~83μm, which ensures that β-spodumene has good reactivity and is beneficial to improving the leaching rate of lithium ions.

[0035] S300: The activated slurry is stirred under the action of an electric field and then leached.

[0036] In this step, the electric field causes lithium to migrate within the spodumene, further enhancing the exchange of lithium ions with sodium or potassium ions and increasing the lithium ion leaching rate. In some embodiments of this application, the current density of the electric field is 0 and not greater than 100 mA / cm². 2 Preferably, it is 10~60 mA / cm 2 Specifically, the current density can be 1 mA / cm². 2 10 mA / cm 2 20mA / cm 2 40 mA / cm 2 55 mA / cm 2 60 mA / cm 2 70 mA / cm2 80 mA / cm 2 85 mA / cm 2 90 mA / cm 2 100mA / cm 2 Equal to or within the range of any two of the above values.

[0037] In addition, in this step, in order to further improve the lithium ion leaching rate while ensuring production efficiency, the leaching temperature can be 60~120℃ and the leaching time can be 2~8h; wherein the leaching temperature is preferably 80~100℃, for example, it can be 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, etc., or within the range of any two of the above values; the leaching time is preferably 4~6h, for example, it can be 2h, 3h, 5h, 6h, 7h, 8h, etc., or within the range of any two of the above values.

[0038] S400 is used to perform solid-liquid separation to obtain a lithium-rich solution and leaching residue.

[0039] The lithium extraction method provided in this application does not require high-pressure treatment, so the reaction conditions are mild; moreover, the extraction method of this application produces less leaching residue and basically no waste gas, which is also beneficial to subsequent processing.

[0040] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0041] Example 1

[0042] This embodiment provides a method for extracting lithium, specifically including the following steps:

[0043] (1) β-spodumene is mixed with an alkaline solution to obtain lithium ore slurry. The alkaline solution is a 20wt% sodium hydroxide solution, and the liquid-to-solid ratio of the alkaline solution to β-spodumene is 10ml / g.

[0044] (2) The lithium ore slurry was mechanically activated using a ball mill to obtain an activated slurry. During mechanical activation, the ball-to-material ratio was 30:1, the rotation speed was 500 rpm, and the time was 120 min. The particle size of β-spodumene in the obtained activated slurry was 53 μm.

[0045] (3) The activated slurry is stirred under the action of an electric field, and then leached. The current density of the electric field is 60 mA / cm². 2 The leaching temperature was 100℃ and the leaching time was 6 hours.

[0046] (4) Solid-liquid separation is performed to obtain lithium-rich solution and leaching residue.

[0047] Example 2

[0048] This embodiment provides a method for extracting lithium, specifically including the following steps:

[0049] (1) β-spodumene is mixed with an alkaline solution to obtain lithium ore slurry. The alkaline solution is a 20wt% sodium hydroxide solution, and the liquid-to-solid ratio of the alkaline solution to β-spodumene is 10ml / g.

[0050] (2) The lithium ore slurry was mechanically activated using a ball mill to obtain an activated slurry. During mechanical activation, the ball-to-material ratio was 15:1, the rotation speed was 300 rpm, and the time was 90 min. The particle size of β-spodumene in the obtained activated slurry was 83 μm.

[0051] (3) The activated slurry is stirred under the action of an electric field, and then leached. The current density of the electric field is 60 mA / cm². 2 The leaching temperature was 100℃ and the leaching time was 6 hours.

[0052] (4) Solid-liquid separation is performed to obtain lithium-rich solution and leaching residue.

[0053] Example 3

[0054] This embodiment provides a method for extracting lithium, specifically including the following steps:

[0055] (1) β-spodumene is mixed with an alkaline solution to obtain lithium ore slurry. The alkaline solution is a 20wt% sodium hydroxide solution, and the liquid-to-solid ratio of the alkaline solution to β-spodumene is 10ml / g.

[0056] (2) The lithium ore slurry was mechanically activated using a ball mill to obtain an activated slurry. During mechanical activation, the ball-to-material ratio was 30:1, the rotation speed was 500 rpm, and the time was 150 min. The particle size of β-spodumene in the obtained activated slurry was 44 μm.

[0057] (3) The activated slurry is stirred under the action of an electric field, and then leached. The current density of the electric field is 80 mA / cm². 2 The leaching temperature was 80℃ and the leaching time was 4 hours.

[0058] (4) Solid-liquid separation is performed to obtain lithium-rich solution and leaching residue.

[0059] Example 4

[0060] This embodiment provides a method for extracting lithium, specifically including the following steps:

[0061] (1) β-spodumene is mixed with an alkaline solution to obtain lithium ore slurry. The alkaline solution is a 15wt% sodium hydroxide solution, and the liquid-to-solid ratio of the alkaline solution to β-spodumene is 15ml / g.

[0062] (2) The lithium ore slurry was mechanically activated using a ball mill to obtain an activated slurry. During mechanical activation, the ball-to-material ratio was 30:1, the rotation speed was 400 rpm, and the time was 150 min. The particle size of β-spodumene in the obtained activated slurry was 62 μm.

[0063] (3) The activated slurry is stirred under the action of an electric field, and then leached. The current density of the electric field is 20 mA / cm². 2 The leaching temperature was 100℃ and the leaching time was 6 hours.

[0064] (4) Solid-liquid separation is performed to obtain lithium-rich solution and leaching residue.

[0065] Example 5

[0066] This embodiment provides a method for extracting lithium, specifically including the following steps:

[0067] (1) β-spodumene is mixed with an alkaline solution to obtain lithium ore slurry. The alkaline solution is a 30wt% sodium hydroxide solution, and the liquid-to-solid ratio of the alkaline solution to β-spodumene is 5ml / g.

[0068] (2) The lithium ore slurry was mechanically activated using a ball mill to obtain an activated slurry. During mechanical activation, the ball-to-material ratio was 30:1, the rotation speed was 300 rpm, and the time was 150 min. The particle size of β-spodumene in the obtained activated slurry was 74 μm.

[0069] (3) The activated slurry is stirred under the action of an electric field, and then leached. The current density of the electric field is 60 mA / cm². 2 The leaching temperature was 100℃ and the leaching time was 6 hours.

[0070] (4) Solid-liquid separation is performed to obtain lithium-rich solution and leaching residue.

[0071] Example 6

[0072] This embodiment provides a method for extracting lithium, which differs from Embodiment 1 in that the concentration of the alkali solution in step (1) is 4%.

[0073] Example 7

[0074] This embodiment provides a method for extracting lithium, which differs from Embodiment 1 in that the liquid-to-solid ratio in step (2) is 1 ml / g.

[0075] Example 8

[0076] This embodiment provides a method for extracting lithium. The main difference from Example 1 is that in step (2), the ball milling time is 30 min, and the strength of β-spodumene in the obtained activated slurry is 88 μm.

[0077] Example 9

[0078] This embodiment provides a method for extracting lithium. The main difference from Embodiment 1 is that in step (2), the rotation speed is 200 rpm, and the β-spodumene strength in the obtained activated slurry is 85 μm.

[0079] Example 10

[0080] This embodiment provides a method for extracting lithium, which differs from Embodiment 1 in that the leaching temperature in step (3) is 60°C.

[0081] Example 11

[0082] This embodiment provides a method for extracting lithium, which differs from Embodiment 1 mainly in that: in step (3), the current density is 8 mA / cm². 2 .

[0083] Example 12

[0084] This embodiment provides a method for extracting lithium, which differs from Embodiment 1 in that the leaching time in step (3) is 2 hours.

[0085] Comparative Example 1

[0086] This comparative example provides a method for extracting lithium, which differs from Example 1 mainly in that the concentration of the alkaline solution in step (1) is 1 wt%.

[0087] In this comparative example, because the concentration of the alkaline solution was reduced to 1%, there were not enough sodium ions to exchange with lithium ions in the system during the spodumene leaching process, thus reducing the lithium leaching rate.

[0088] Comparative Example 2

[0089] This comparative example provides a method for extracting lithium, which differs from Example 1 mainly in that step (2) is omitted.

[0090] In this comparative example, because the mixed slurry was not mechanically activated, the lithium in β-spodumene was encapsulated by aluminum and silicon. The leaching process of spodumene requires breaking the outer encapsulation layer before lithium can be leached, thus reducing the lithium leaching rate.

[0091] Comparative Example 3

[0092] This comparative example provides a method for extracting lithium, specifically including the following steps:

[0093] (1) β-spodumene is mixed with an alkaline solution to obtain lithium ore slurry. The alkaline solution is a 20wt% sodium hydroxide solution, and the liquid-to-solid ratio of the alkaline solution to β-spodumene is 10ml / g.

[0094] (2) The lithium ore slurry was mechanically activated using a ball mill to obtain an activated slurry. During mechanical activation, the ball-to-material ratio was 30:1, the rotation speed was 500 rpm, and the time was 150 min. The particle size of β-spodumene in the obtained activated slurry was 50 μm.

[0095] (3) Stir and activate the slurry, then leach it. The leaching temperature is 100℃ and the leaching time is 6h.

[0096] (4) Solid-liquid separation is performed to obtain lithium-rich solution and leaching residue.

[0097] In this comparative example, since no electric field was added during the leaching process, the migration rate of lithium during leaching was reduced, thus reducing the lithium leaching rate.

[0098] The preparation parameters for each embodiment and comparative example are shown in Table 1:

[0099] Table 1

[0100]

[0101] Application examples

[0102] The mass and lithium content of the leaching residue in the above examples and comparative examples were detected by ICP method, and the lithium extraction rate was calculated based on the mass and lithium content of the raw materials. The results are shown in Table 2.

[0103] Table 2

[0104]

[0105] From Table 1 and Table 2, we can see that:

[0106] (1) As can be seen from the comprehensive examples 1 to 5, the method of mechanical activation and electric field synergistic enhancement of lithium extraction in alkaline medium provided in this application can achieve efficient lithium leaching from spodumene with a lithium leaching rate of ≥90% and high process economy.

[0107] (2) As can be seen from Examples 1 and 6, the sodium hydroxide concentration in Example 1 is 20 wt%, compared with the sodium hydroxide concentration in Example 6 is 4 wt%. The lithium leaching rate in Example 1 is 95%, while the lithium leaching rate in Example 6 is 78%. This shows that the present application has obtained a higher lithium leaching rate by further controlling the alkali concentration within the preferred range.

[0108] (3) As can be seen from Examples 1 and 7, the liquid-solid ratio of alkaline solution to spodumene in Example 1 is 10 ml / g. Compared with the liquid-solid ratio of alkaline solution to spodumene in Example 7 is 1 ml / g, the lithium leaching rate in Example 1 is 95%, while the lithium leaching rate in Example 7 is 70%. This shows that the present application has obtained a higher lithium leaching rate by further controlling the liquid-solid ratio within the preferred range.

[0109] (4) As can be seen from Examples 1 and 8-9, the mechanical activation time in Example 1 was 150 min and the ball milling speed was 500 rpm, the mechanical activation time in Example 8 was 20 min, and the ball milling speed in Example 9 was 200 rpm. The lithium leaching rate in Example 1 was 95%, the lithium leaching rate in Example 8 was 85%, and the lithium leaching rate in Example 9 was 87%. This shows that by further controlling the mechanical activation time and speed within the preferred range, this application can better expose the lithium-containing mineral phase in spodumene to the reaction medium, thereby obtaining a higher lithium leaching rate.

[0110] (5) As can be seen from Examples 1 and 10-12, the current density in Example 1 was 60 mA / cm2, the leaching temperature was 100 °C, and the leaching time was 6 h; the leaching temperature in Example 10 was 60 °C; the current density in Example 11 was 8 mA / cm2; and the leaching time in Example 12 was 2 h. The lithium leaching rate in Example 1 was 95%, the lithium leaching rate in Example 10 was 84%, the lithium leaching rate in Example 11 was 86%, and the lithium leaching rate in Example 12 was 78%. This shows that by further controlling the electric field-enhanced leaching conditions within the preferred range, the lithium leaching rate in this application is relatively high.

[0111] (6) As can be seen from Example 1 and Comparative Example 1, the concentration of alkaline solution in Example 1 is 20 wt%, compared with the concentration of alkaline solution in Comparative Example 1 is 1 wt%. The lithium leaching rate in Example 1 is 95%, and the lithium leaching rate in Comparative Example 1 is 9%. This shows that in order to achieve efficient leaching of lithium from spodumene, it is necessary to ensure the concentration of sodium ions in the system that can be replaced by lithium ions.

[0112] (7) As can be seen from Example 1 and Comparative Example 2, Example 1 uses mechanical activation to expose the lithium-containing mineral phase in β-spodumene to the reaction medium. Compared with Comparative Example 3, which does not use mechanical activation, the lithium leaching rate in Example 1 is 95%, and the lithium leaching rate in Comparative Example 2 is 65%. This shows that mechanical activation can change the lattice of the lithium-containing mineral phase, reduce the bond energy between lithium and surrounding atoms, and increase the lithium leaching rate.

[0113] (8) As can be seen from Example 1 and Comparative Example 3, Example 1 uses electric field enhanced leaching. Compared with Comparative Example 3, which does not use electric field enhanced leaching, the lithium leaching rate in Example 1 is 95%, and the lithium leaching rate in Comparative Example 3 is 68%. This shows that the electric field enhances the lithium leaching by enhancing the lithium migration rate, thereby improving the lithium leaching rate.

[0114] In summary, this application presents a method for efficient lithium extraction from β-spodumene using a synergistic enhancement of mechanical activation and electric field in a 4%–40% alkaline solution environment. By employing an alkaline solution as the leaching agent and introducing mechanical activation, lattice distortion and dislocations occur in the lithium-bearing mineral phase of β-spodumene. Simultaneously, the periodicity of particle arrangement in the lattice is partially lost, forming lattice defects, leading to increased internal lattice energy, altered surface properties, and enhanced reactivity. The activated spodumene is further enhanced by an electric field to increase the lithium migration rate and improve the lithium leaching rate. Under optimal conditions, the lithium leaching rate exceeds 90%, resulting in high economic benefits.

[0115] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for extracting lithium, characterized in that, It includes the following steps: The lithium ore slurry is mechanically activated to obtain an activated slurry; then the activated slurry is stirred under the action of an electric field and leached; then solid-liquid separation is performed to obtain a lithium-rich solution and leaching residue. The lithium ore slurry comprises β-spodumene and an alkaline solution, wherein the concentration of the alkaline solution is 10wt%~30wt%. In the activated slurry, the particle size of the β-spodumene is 15~83μm; In the leaching step, the leaching temperature is 60~120℃ and the leaching time is 2~8h.

2. The method for extracting lithium according to claim 1, characterized in that, The current density of the electric field is greater than 0 and not greater than 100 mA / cm². 2 .

3. The method for extracting lithium according to claim 2, characterized in that, The current density of the electric field is 10~60 mA / cm². 2 .

4. The method for extracting lithium according to claim 1, characterized in that, The mechanical activation was performed using a ball mill, with a ball-to-material ratio of 10:1 to 35:1, a rotation speed of 200 to 600 rpm, and a time of 10 to 240 min.

5. The method for extracting lithium according to claim 4, characterized in that, The ball-to-material ratio is 15:1 to 30:1, the rotation speed is 300 to 500 rpm, and the time is 30 to 150 min.

6. The method for extracting lithium according to claim 1, characterized in that, In the lithium ore slurry, the liquid-to-solid ratio of the alkali solution and the β-spodumene is 1~15 ml / g.

7. The method for extracting lithium according to claim 6, characterized in that, The liquid-to-solid ratio of the alkaline solution to the β-spodumene is 4~12 ml / g.

8. The method for extracting lithium according to claim 1, characterized in that, The leaching temperature is 80~100℃, and the leaching time is 4~6h.

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