Method for extracting lithium by leaching spodumene

Abstract

The invention provides a method for extracting lithium by leaching spodumene. The method comprises the following steps: roasting a mixture of spodumene concentrate and a roasting aid to obtain roasted clinker; and under the condition that an external field is applied, acid leaching is conducted on the roasted clinker, solid-liquid separation is conducted, and lithium leaching liquid and spodumene smelting slag are obtained. According to the method, roasting transformation is optimized through a process route of combining one-step additive roasting transformation with external field enhanced leaching lithium extraction, the process flow is shortened, meanwhile, external field synergistic enhanced leaching is adopted, and efficient leaching of the lithium element in spodumene and selective leaching of the lithium element are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of inorganic chemical industry, in particular to lithium extraction from lithium ore, and in particular to a method for extracting lithium by leaching spodumene. Background Art

[0002] Lithium is widely used in smelting, medicine, glass and ceramics, chemical industry, aviation, new energy, military industry and nuclear energy. Lithium resources are mainly found in ores and salt lake brines. At present, the technology of lithium extraction from hard rock mines is relatively mature, and 72% of lithium salt products come from hard rock lithium mines. Spodumene has become the most commonly used raw material for lithium extraction from ores because of its wide distribution, easy mining and high grade. Spodumene lithium extraction technologies include sulfuric acid method, sulfate method, limestone method, chlorination roasting method, pressure cooking method, fluorine chemical method or roasting method. At present, the mainstream lithium extraction process of spodumene adopts a two-stage roasting method, which has problems such as high roasting temperature and high energy consumption.

[0003] CN102765734A discloses a method for extracting lithium from spodumene to prepare lithium salt, which includes the steps of transition roasting, cooling ball milling, acid roasting, slurry neutralization, separation washing and purification. The whole preparation process is cumbersome and requires two-step roasting to achieve lithium extraction, resulting in high energy consumption and low efficiency.

[0004] CN108165767A discloses a method for leaching spodumene based on microwave and pressure field. The method requires first grinding the spodumene concentrate to a particle size of 74 μm accounting for more than 80%, adding 2-8% of the total mass of the raw materials to coal powder, and the coal powder particle size is 74 μm accounting for more than 80%, mixing evenly to obtain a mixture, and then sintering the mixture under microwave irradiation to achieve crystal transformation before subsequent leaching and separation and purification of purified lithium salt can be carried out.

[0005] CN103183366A discloses a method for extracting lithium salt from spodumene by soda ash pressure leaching, which comprises roasting and transforming the spodumene concentrate at 1150°C-1250°C, mixing with soda ash, and pressure leaching to obtain lithium carbonate, and then acidifying and transforming the lithium carbonate to obtain soluble lithium salt.

[0006] Although the prior art discloses technical solutions for extracting lithium by roasting in one step, they all require the spodumene to be crystallized before subsequent leaching treatment. Most of the processes are complicated or require the cooperation of strong acid or strong base to be implemented, which is not suitable for large-scale industrial applications.

[0007] Therefore, it is of great significance to develop a lithium extraction method that does not require transition roasting, has a simple process, and has high lithium extraction efficiency. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for leaching and extracting lithium from spodumene, wherein the method introduces a roasting aid and combines the effect of external field strengthening, optimizes the roasting transformation through a one-step auxiliary roasting transformation combined with an external field-strengthened leaching and lithium extraction process route, and shortens the process flow. The present invention adopts external field synergistic enhanced leaching to achieve selective and efficient leaching of lithium in spodumene, improves the leaching efficiency, and significantly reduces the content of impurity elements such as aluminum and silicon.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] The present invention provides a method for extracting lithium by leaching spodumene, the method comprising:

[0011] A mixture of spodumene concentrate and a roasting aid is roasted to obtain roasted clinker; the roasted clinker is acid-leached under the condition of applying an external field, and the solid and liquid are separated to obtain a lithium leaching solution and spodumene smelting slag.

[0012] The present invention analyzes the mineral phase structure of spodumene, combines the Al2O3-SiO2-MeO (Me: K / Na / Ca, etc.) ternary phase diagram, introduces a roasting aid, utilizes the roasting aid to destroy the bonding state between lithium and other elements in spodumene, and can achieve efficient mineral phase reconstruction of spodumene without high-temperature transformation roasting, effectively activates the lithium-containing mineral phase in spodumene, and improves the reaction activity of inert Li in spodumene. Furthermore, under the synergistic effect of an external field, efficient leaching of lithium in spodumene is achieved, the process of leaching and extracting lithium is shortened, the amount of reagents used is reduced, and the common development of economic and environmental benefits is achieved.

[0013] Preferably, the roasting aid comprises any one of fluoride, sodium salt or potassium salt, or a combination of at least two thereof.

[0014] Preferably, the roasting aid comprises any one of potassium fluoride, sodium fluoride, sodium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, sodium acetate, potassium acetate, sodium chloride, potassium chloride, sodium nitrate or potassium nitrate, or a combination of at least two thereof. Typical but non-limiting combinations include potassium fluoride and sodium fluoride, sodium sulfate and potassium sulfate, sodium carbonate and potassium carbonate, sodium acetate and potassium acetate, sodium chloride and potassium chloride, sodium nitrate and potassium nitrate or sodium fluoride and sodium sulfate.

[0015] The mass ratio of spodumene concentrate to roasting aid affects the roasting temperature and lithium leaching rate. If the roasting aid is excessive, although it can effectively reduce the roasting temperature and increase the lithium leaching rate, the excessive roasting aid will cause the production cost to be too high. If the roasting aid is insufficient, the roasting cannot be reduced, and the transformation of the spodumene mineral phase structure cannot be effectively achieved, resulting in a low lithium leaching rate.

[0016] Preferably, the mass ratio of the spodumene concentrate to the roasting aid is (1-10):1, for example, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the mixing method of the spodumene concentrate and the roasting aid includes any one of mechanical stirring, rotation or ball milling, or a combination of at least two of them.

[0018] In the present invention, during the mixing process of spodumene concentrate and the roasting aid, the roasting aid is in full contact with the spodumene, and the mass transfer resistance between the roasting aid and the spodumene is reduced through the coupling of the mechanical field and the chemical field, the solid-solid mass transfer process is strengthened, and the roasting aid is promoted to destroy the bonding state between the lithium element and other elements in the spodumene. Without high-temperature transformation roasting, efficient mineral phase reconstruction of the spodumene can be achieved, the lithium-containing mineral phase in the spodumene is effectively activated, and the reaction activity of the inert Li in the spodumene is improved.

[0019] Preferably, the calcination temperature is 750°C-1000°C, for example, it can be 750°C, 800°C, 850°C, 900°C, 950°C or 1000°C, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 750°C-850°C.

[0020] Preferably, the calcination time is 10 min-60 min, for example, it can be 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the external field comprises an electrochemical field and / or an ultrasonic field.

[0022] In the present invention, the electrochemical field refers to the spodumene concentrate after the bonding state of lithium and other elements is destroyed by the action of the roasting aid. By applying an electric field during the leaching process, the transfer of electrons can be promoted and the reaction path can be changed, thereby significantly reducing the leaching potential and achieving efficient leaching of lithium.

[0023] In the present invention, the ultrasonic field refers to applying the ultrasonic field during the leaching process, utilizing the ultrasonic cavitation effect of the ultrasonic field to strengthen the spodumene leaching process and achieve efficient leaching of lithium elements.

[0024] Preferably, the acid leaching process includes acid leaching including mixing the roasted clinker with acid solution to obtain an acid leaching slurry.

[0025] Preferably, in the acid leaching slurry, the solid-to-liquid ratio of the calcined clinker to the acid solution is 2 mL / g-10 mL / g, for example, 2 mL / g, 3 mL / g, 4 mL / g, 5 mL / g, 6 mL / g, 7 mL / g, 8 mL / g, 9 mL / g or 10 mL / g, including but not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the acid leaching time is 30 min-90 min, for example, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min or 90 min, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the acid leaching temperature is 20°C-95°C, for example, it can be 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 95°C, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the acid solution includes any one of sulfuric acid, hydrochloric acid, nitric acid or phosphoric acid, or a combination of at least two of them.

[0029] Preferably, the concentration of the acid solution is 2wt%-30wt%, for example, it can be 2wt%, 4wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, 20wt%, 22wt%, 24wt%, 26wt%, 28wt% or 30wt%, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the method further comprises washing the spodumene smelting slag obtained after solid-liquid separation.

[0031] Preferably, during the water washing process, the solid-liquid ratio of spodumene smelting slag to water is 2 mL / g-10 mL / g, for example, it can be 2 mL / g, 3 mL / g, 4 mL / g, 5, 6 mL / g, 7 mL / g, 8 mL / g, 9 mL / g or 10 mL / g, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the water washing temperature is 20°C-70°C, for example, it can be 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C or 70°C, including but not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, the water washing method includes single-stage washing and / or multi-stage countercurrent washing.

[0034] In the present invention, the monopolar washing means washing the filter residue after solid-liquid separation of the leached slurry, and returning the washing water to the leaching process.

[0035] In the present invention, multi-stage countercurrent washing means that after the leaching slurry is separated into solid and liquid, the solid material is countercurrently washed, and the washing liquid is returned to the previous solid slag washing process, and so on, so as to give full play to the role of the washing liquid, and the last stage of washing is washed with fresh water.

[0036] In the present invention, the washing water obtained by washing the spodumene smelting slag is recycled, the lithium-rich solution is used to prepare lithium series products after further purification and separation, and the spodumene leaching slag is used to prepare aluminum silicon series products.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention introduces a roasting aid and combines it with an external field strengthening effect. Through a one-step auxiliary roasting transformation combined with an external field strengthening leaching and lithium extraction process route, the roasting aid is used to destroy the bonding state between the lithium element and other elements in the spodumene. No high-temperature roasting transformation is required, so that the lithium-containing mineral phase in the spodumene can be effectively activated, the reaction activity of the inert Li in the spodumene is improved, and the efficient mineral phase reconstruction of the spodumene is achieved. Furthermore, under the synergistic effect of the external field, the leaching and lithium extraction is strengthened, the efficient leaching of the lithium element in the spodumene is achieved, the process of leaching and lithium extraction is shortened, the amount of reagents used is reduced, and the common development of economic and environmental benefits is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a process flow chart of the method for leaching lithium from spodumene in Example 1 of the present invention. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0041] In order to clearly illustrate the technical solution of the present invention, the main phases of the spodumene concentrate in the specific implementation method are α-LiAlSi2O6, albite, quartz and muscovite, of which the lithium oxide grade is 5.81%, and the main elements are silicon and aluminum, with the content accounting for 54.85% and 17.85% respectively. The above description is only for the purpose of clearly illustrating the technical solution of the present invention and is not regarded as a further limitation of the present invention.

[0042] Example 1

[0043] This embodiment provides a method for leaching spodumene to extract lithium. The process flow chart of the method is as follows: Figure 1As shown, specifically:

[0044] (1) Spodumene concentrate with a mass ratio of 6:1 and a roasting aid (potassium sulfate and sodium fluoride with a mass ratio of 2:1) are fully mixed, and the mixture is reacted at a high temperature of 850° C. for 60 minutes to obtain roasted clinker.

[0045] (2) Sulfuric acid having a concentration of 10 wt % is mixed with the roasted clinker obtained in step (1) to obtain an acid leaching slurry, wherein the liquid-to-solid ratio of the acid leaching slurry is 6 mL / g, and the leaching is carried out in a mechanochemically enhanced reactor, and the enhanced leaching is carried out under the enhanced action of the mechanochemical field, the leaching temperature is 60° C., and the leaching time is 30 min, and then the acid leaching slurry is filtered and separated to obtain a lithium leaching solution and spodumene smelting slag. The spodumene smelting slag is washed with water by a single-stage washing method, wherein the liquid-to-solid ratio of the water washing is 6 mL / g, and the washing water temperature is 60° C., and the washing water is returned to step (2) for acid leaching.

[0046] By dissolving and sampling the spodumene leaching residue, the residual Li2O in the spodumene smelting residue was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 97.7%.

[0047] Example 2

[0048] This embodiment provides a method for leaching spodumene to extract lithium, and the method is specifically as follows:

[0049] (1) Spodumene concentrate and a roasting aid (sodium fluoride) in a mass ratio of 1.5:1 are fully mixed, and the mixture is reacted at a high temperature of 750° C. for 30 minutes to obtain roasted clinker.

[0050] (2) mixing hydrochloric acid with a concentration of 30wt% with the roasted clinker obtained in step (1) to obtain an acid leaching slurry, wherein the liquid-to-solid ratio of the acid leaching slurry is 4mL / g, and the leaching is carried out in an electrochemical strengthening field, and the strengthening leaching is carried out under the strengthening effect of the electrochemical field, the leaching temperature is 70°C, and the leaching time is 60min, and then the acid leaching slurry is filtered and separated to obtain a lithium leaching solution and spodumene smelting slag. The spodumene smelting slag is washed with water by a single-stage washing method, the liquid-to-solid ratio of the water washing is 4mL / g, the washing water temperature is 60°C, and the washing water is returned to step (2) for acid leaching.

[0051] By dissolving and sampling the spodumene leaching residue, the residual Li2O in the spodumene smelting residue was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 96.2%.

[0052] Example 3

[0053] This embodiment provides a method for leaching spodumene to extract lithium, and the method is specifically as follows:

[0054] (1) Spodumene concentrate with a mass ratio of 10:1 and a roasting aid (sodium carbonate and sodium fluoride with a mass ratio of 3:1) are fully mixed, and the mixture is reacted at a high temperature of 750° C. for 40 minutes to obtain roasted clinker.

[0055] (2) mixing nitric acid with a concentration of 20wt% with the roasted clinker obtained in step (1) to obtain an acid leaching slurry, wherein the liquid-to-solid ratio of the acid leaching slurry is 5mL / g, and the leaching is carried out in an ultrasonic enhanced field, the ultrasonic frequency is 40kHz, and the enhanced leaching is carried out under the enhanced effect of the ultrasonic field, the leaching temperature is 90°C, and the leaching time is 30min, and then the acid leaching slurry is filtered and separated to obtain a lithium leaching solution and spodumene smelting slag. The spodumene smelting slag is washed with water by a three-stage countercurrent washing method, the liquid-to-solid ratio of the water washing is 5mL / g, the washing water temperature is 70°C, and the washing water is returned to step (2) for acid leaching.

[0056] By dissolving and sampling the spodumene leaching residue, the residual Li2O in the spodumene smelting residue was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 95.4%.

[0057] Example 4

[0058] This embodiment provides a method for leaching spodumene to extract lithium, and the method is specifically as follows:

[0059] (1) Spodumene concentrate with a mass ratio of 8:1 and a roasting aid (potassium sulfate and sodium fluoride with a mass ratio of 2:1) are fully mixed, and the mixture is reacted at a high temperature of 820° C. for 10 minutes to obtain roasted clinker.

[0060] (2) mixing phosphoric acid having a concentration of 30wt% with the roasted clinker obtained in step (1) to obtain an acid leaching slurry, wherein the liquid-to-solid ratio of the acid leaching slurry is 2mL / g, and the leaching is carried out in a mechanochemically enhanced reactor, and the enhanced leaching is carried out under the enhanced action of the mechanochemical field, the leaching temperature is 20°C, the leaching time is 90min, and then the acid leaching slurry is filtered and separated to obtain a lithium leaching solution and spodumene smelting slag. The spodumene smelting slag is washed with water by a three-stage countercurrent washing method, the liquid-to-solid ratio of the water washing is 10mL / g, the washing water temperature is 50°C, and the washing water is returned to step (2) for acid leaching.

[0061] The spodumene leaching residue was dissolved and sampled, the residual Li2O in the spodumene smelting slag was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 95.7%.

[0062] Example 5

[0063] This embodiment provides a method for leaching spodumene to extract lithium, and the method is specifically as follows:

[0064] (1) Spodumene concentrate and a roasting aid (potassium sulfate and sodium fluoride in a mass ratio of 1:1) are fully mixed, and the mixture is reacted at a high temperature of 850° C. for 60 minutes to obtain roasted clinker.

[0065] (2) Sulfuric acid with a concentration of 5wt% is mixed with the roasted clinker obtained in step (1) to obtain an acid leaching slurry, wherein the liquid-to-solid ratio of the acid leaching slurry is 6mL / g, and the leaching is carried out in a mechanochemical enhanced reactor, and the enhanced leaching is carried out under the enhanced action of the mechanochemical field, the leaching temperature is 60°C, and the leaching time is 30min, and then the acid leaching slurry is filtered and separated to obtain a lithium leaching solution and spodumene smelting slag. The spodumene smelting slag is washed with water by a single-stage washing method, the liquid-to-solid ratio of the water washing is 2mL / g, the washing water temperature is 20°C, and the washing water is returned to step (2) for acid leaching.

[0066] By dissolving and sampling the spodumene leaching residue, the residual Li2O in the spodumene smelting residue was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 96.7%.

[0067] Comparative Example 1

[0068] This comparative example provides a method for extracting lithium by leaching spodumene, which is the same as the method in Example 1 except that no roasting aid is added.

[0069] By dissolving and sampling the spodumene leaching residue, the residual Li2O in the spodumene smelting residue was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 93.2%.

[0070] Comparative Example 2

[0071] This comparative example provides a method for leaching spodumene to extract lithium, which is the same as the method in Example 1 except that the mechanochemical field is not added.

[0072] By dissolving and sampling the spodumene leaching residue, the residual Li2O in the spodumene smelting residue was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 92.9%.

[0073] Comparative Example 3

[0074] This comparative example provides a method for extracting lithium by enhanced leaching of spodumene, the method comprising:

[0075] (1) Spodumene is first subjected to high temperature roasting transformation at a temperature of 1150° C. for 60 min, and then acid-roasted with sulfuric acid having a concentration of 98 wt % at 250° C. for 30 min to obtain acid-roasted clinker.

[0076] (2) the acidified roasted clinker obtained in step (1) is subjected to water leaching, the leaching liquid-to-solid ratio is 4 mL / g, the leaching temperature is 20° C., and the leaching time is 30 min, and then the acid leaching slurry is filtered and separated to obtain lithium leaching solution and spodumene smelting slag, and the spodumene smelting slag is washed with water by single-stage washing, the liquid-to-solid ratio of the water washing is 4 mL / g, the washing water temperature is 40° C., and the washing water is returned to step (2) for acid leaching.

[0077] By dissolving and sampling the spodumene leaching residue, the residual Li2O in the spodumene smelting residue was tested, and the lithium leaching rate was calculated. The lithium leaching rate in the spodumene obtained in this embodiment was 92.3%.

[0078] The present invention introduces a roasting aid and combines it with an external field strengthening effect, and transforms the process route of leaching and extracting lithium by a one-step auxiliary roasting transformation combined with an external field strengthening, and utilizes a roasting aid to destroy the bonding state of lithium and other elements in spodumene. By low-temperature roasting, the lithium-containing mineral phase in spodumene is effectively activated, and the reaction activity of inert Li in spodumene is improved, and the low-temperature and efficient mineral phase reconstruction of spodumene is achieved. Further, the leaching and extraction of lithium is strengthened under the synergistic effect of the external field, and only acid can be used to achieve efficient leaching of lithium elements in spodumene, shortening the process of leaching and extracting lithium. According to Examples 1 to 5, the method provided by the present invention only requires one-step roasting to achieve a lithium leaching rate of more than 95.4% in spodumene.

[0079] Compared with Example 1, in Comparative Example 3, the auxiliary agent roasting in step (1) is replaced by a two-step roasting method of high-temperature transformation roasting and acidification roasting to obtain a roasted clinker whose mineral phase structure is mainly lithium sulfate, and then a lithium-rich solution is obtained after leaching. In addition, no mechanochemical field strengthening is performed in step (2). Compared with Example 1, this comparative example has the problems of high energy consumption in the two-stage roasting and low lithium leaching rate.

[0080] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for leaching lithium from spodumene, characterized in that: The method comprises: A mixture of spodumene concentrate and a roasting aid is roasted to obtain roasted clinker; the roasted clinker is acid-leached under the condition of applying an external field, and the solid and liquid are separated to obtain a lithium leaching solution and spodumene smelting slag.

2. The method according to claim 1, characterized in that The roasting aid includes any one of fluoride, sodium salt or potassium salt or a combination of at least two thereof; Preferably, the roasting aid includes any one of potassium fluoride, sodium fluoride, sodium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, sodium acetate, potassium acetate, sodium chloride, potassium chloride, sodium nitrate or potassium nitrate, or a combination of at least two thereof.

3. The method according to claim 1 or 2, characterized in that The mass ratio of the spodumene concentrate to the roasting aid is (1-10):1; Preferably, the mixing method of the spodumene concentrate and the roasting aid includes any one of mechanical stirring, rotary stirring or ball milling, or a combination of at least two of them.

4. The method according to any one of claims 1 to 3, characterized in that: The calcination temperature is 750°C-1000°C, preferably 750°C-850°C; Preferably, the calcination time is 10 min-60 min.

5. The method according to any one of claims 1 to 4, characterized in that: The external field includes any one of an electrochemical field and / or an ultrasonic field, or a combination of at least two of them.

6. The method according to any one of claims 1 to 5, characterized in that: The acid leaching comprises mixing the roasted clinker with acid solution to obtain an acid leaching slurry; Preferably, in the acid leaching slurry, the solid-to-liquid ratio of the roasted clinker to the acid solution is 2 mL / g-10 mL / g.

7. The method according to any one of claims 1 to 6, characterized in that: The acid leaching time is 30min-90min; Preferably, the acid leaching temperature is 20°C-95°C.

8. The method according to claim 6 or 7, characterized in that The acid solution includes any one of sulfuric acid, hydrochloric acid, nitric acid or phosphoric acid, or a combination of at least two thereof; Preferably, the concentration of the acid solution is 2wt%-30wt%.

9. The method according to any one of claims 1 to 8, characterized in that: The method further comprises washing the spodumene smelting slag obtained after solid-liquid separation.

10. The method according to claim 9, characterized in that During the water washing process, the solid-to-liquid ratio of spodumene smelting slag to water is 2 mL / g-10 mL / g; Preferably, the water washing temperature is 20°C-70°C; Preferably, the water washing method includes single-stage washing and / or multi-stage countercurrent washing.

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