Method for recovering lithium in sodium aluminate solution
By using the co-precipitation reaction in sodium aluminate solution to generate solid precipitates, the complex problem of the existing lithium enrichment process is solved, and efficient and simple lithium recovery is achieved. The obtained lithium-rich solid phase has low impurities and high recovery rate.
Patent Information
- Application Number
- CN202411468991.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-03-28
AI Technical Summary
The existing process of enriching lithium from sodium aluminate solution is complex.
By adding a compound containing carbonate and/or bicarbonate to the lithium-containing sodium aluminate solution, co-precipitation reaction is carried out to produce a solid-liquid precipitate as Li2Al4CO3(OH)12·3H2O solid precipitate, and solid-liquid separation is performed to obtain a lithium-rich solid phase.
It achieves simple process, short process, few types of raw materials used, low content of lithium-rich solid-phase impurities and high lithium recovery rate, which helps subsequent lithium applications.
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Figure CN119706903A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of lithium recovery, and in particular to a method for recovering lithium from a sodium aluminate solution. Background Art
[0002] Lithium is widely used in various fields due to its good conductivity and ductility. Domestic high-quality lithium mineral resources are scarce, the separation of magnesium and lithium in China's high-magnesium brine from salt lakes is difficult, and the limited increase in production capacity of foreign lithium giants has led to insufficient supply. In the long run, the lithium resources in minerals and brine will be difficult to meet the needs of human sustainable development.
[0003] my country is rich in lithium resources associated with bauxite, especially in the central region, where the lithium content is high, with Li2O greater than 0.1%. In the Bayer process of alumina production, about 80% of lithium enters the solution during the Bayer process dissolution and eventually enters the alumina product. Therefore, the alumina produced with this type of bauxite as raw material has a high lithium content. Efficiently recycling lithium resources in the alumina production process will not only help improve the quality of alumina products and eliminate the adverse effects on downstream aluminum electrolysis, but also open up new ways for the economic and efficient use of low-grade lithium-rich bauxite, which is also of great significance to the strategic security of my country's lithium resources.
[0004] Most of the existing recovery methods currently use the method of seed adsorption enrichment, which uses the principle of adsorption. There are problems such as complex process flow, long reaction time, low lithium content in the lithium-rich solid phase, low lithium enrichment efficiency, and high cost. Summary of the invention
[0005] The present application provides a method for recovering lithium from a sodium aluminate solution to solve the following technical problem: the existing process for enriching lithium from a sodium aluminate solution is complicated.
[0006] The present invention provides a method for recovering lithium from a sodium aluminate solution, wherein the sodium aluminate solution contains lithium, comprising the following steps:
[0007] adding a coprecipitant to a sodium aluminate solution containing lithium to obtain a mixed solution;
[0008] The mixed solution is subjected to a coprecipitation reaction under heating and stirring conditions to obtain a mixed slurry; and
[0009] Performing solid-liquid separation on the mixed slurry to obtain a lithium-rich solid phase;
[0010] Wherein, the coprecipitant is a compound containing carbonate and / or bicarbonate.
[0011] Optionally, in the mixed solution, the molar concentration ratio of the carbonate and / or bicarbonate to the molar concentration of lithium ions is 1:2 to 2:1.
[0012] Optionally, the heating temperature is 50°C to 100°C, and the stirring time is 0.5h to 1.0h.
[0013] Optionally, a coprecipitant is added to the lithium-containing sodium aluminate solution to obtain a mixed solution, specifically comprising:
[0014] adding a coprecipitant and a stabilizer to a sodium aluminate solution containing lithium to obtain a mixed solution;
[0015] The stabilizer is mannitol and / or sorbitol.
[0016] Optionally, in the mixed solution, the concentration of mannitol and / or sorbitol is 1 ppm to 10 ppm.
[0017] Optionally, the solid-liquid separation of the mixed slurry to obtain a lithium-rich solid phase specifically includes:
[0018] The mixed slurry is subjected to solid-liquid separation to obtain a solid phase material; the solid phase material is washed with hot water to obtain a lithium-rich solid phase.
[0019] Optionally, the temperature of the hot water is 80°C to 100°C.
[0020] Optionally, the coprecipitant is carbonate and / or bicarbonate.
[0021] Optionally, the coprecipitant is a saturated solution containing carbonate and / or a saturated solution containing bicarbonate.
[0022] The above technical solution provided by the present invention has the following advantages compared with the prior art:
[0023] The present invention provides a method for recovering lithium from a sodium aluminate solution. The method comprises the steps of adding a compound containing carbonate and / or bicarbonate to the lithium-containing sodium aluminate solution, wherein the carbonate or bicarbonate ions react with the lithium ions and aluminate ions in the sodium aluminate solution to form Li2Al4CO3(OH) 12 ·3H2O solid precipitate, the solid precipitate is stable in shape and not easy to decompose. After directly performing solid-liquid separation, a lithium-rich solid phase can be obtained. This method has a simple process, a short flow, and uses fewer types of raw materials. The lithium-rich solid phase obtained by this method has a low impurity content and a high lithium recovery rate, which is conducive to the subsequent application of lithium. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0026] Figure 1 A flow chart of a method for recovering lithium from sodium aluminate solution provided in an embodiment of the present application. DETAILED DESCRIPTION
[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0028] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.
[0029] In this application, in the absence of any contrary description, the terms including "including" and the like mean "including but not limited to". In this article, relational terms such as "first" and "second" and the like are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A, B can be singular or plural. In this article, "at least one" refers to one or more, and "plurality" refers to two or more. "At least one", "the following at least one (individual)" or similar expressions thereof refer to any combination of these items, including any combination of singular (individual) or plural (individual). For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or plural, respectively.
[0030] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.
[0031] The present invention provides a method for recovering lithium from a sodium aluminate solution, wherein the sodium aluminate solution contains lithium, comprising the following steps:
[0032] adding a coprecipitant to a sodium aluminate solution containing lithium to obtain a mixed solution;
[0033] The mixed solution is subjected to a coprecipitation reaction under heating and stirring conditions to obtain a mixed slurry; and
[0034] Performing solid-liquid separation on the mixed slurry to obtain a lithium-rich solid phase;
[0035] Wherein, the coprecipitant is a compound containing carbonate and / or bicarbonate.
[0036] In the above embodiment, the method is to add a saturated solution containing carbonate and / or a saturated solution containing bicarbonate to the lithium-containing sodium aluminate solution, wherein the carbonate or bicarbonate ions react with the lithium ions and aluminate ions in the sodium aluminate solution to form Li2Al4CO3(OH) 12 ·3H2O solid precipitate, the solid precipitate has a stable shape and is not easy to decompose. The lithium-rich solid phase can be obtained by directly performing solid-liquid separation.
[0037] As an optional implementation, in the mixed solution, the ratio of the molar concentration of the carbonate and / or bicarbonate to the molar concentration of the lithium ions is 1:2 to 2:1.
[0038] In the above embodiment, the reason for controlling the molar concentration ratio of carbonate and / or bicarbonate to lithium ions in the mixed solution is that: in the present application, the formation of the coprecipitation reactant is mainly achieved by controlling the content of carbonate / bicarbonate ions in the mixed solution. If the content of carbonate / bicarbonate ions in the mixed solution is too low, the generated precipitate may be lithium carbonate and other carbonates. Even if the generated precipitate is Li2Al4CO3(OH) 12 ·3H2O, the lithium in the solution cannot be completely precipitated, resulting in a low leaching rate of the generated lithium; if the content of carbonate / bicarbonate ions in the mixed solution is too high, the viscosity of the mixed solution will increase, and the lithium enrichment efficiency will also be reduced. Exemplarily, the molar concentration ratio of the carbonate and / or bicarbonate to the molar concentration of the lithium ion is 1:2, 1:1 or 2:1.
[0039] As an optional embodiment, the mixed solution is subjected to a coprecipitation reaction to obtain a mixed slurry, which specifically includes:
[0040] The mixed solution is heated and stirred to achieve a coprecipitation reaction to obtain a mixed slurry.
[0041] The heating temperature is 50° C. to 100° C., and the stirring time is 0.5 h to 1.0 h.
[0042] In the above embodiment, heating and stirring can speed up the coprecipitation reaction. Controlling the heating temperature to 50°C to 100°C and the time to 0.5h to 1.0h can better control the reaction rate and the final reaction result. If the temperature is lower than 50°C, the reaction is slow and the reaction rate is low; if the temperature is higher than 100°C, the product produced during the precipitation process is affected, resulting in a still low reaction rate and more energy consumption. Exemplarily, the heating temperature during the coprecipitation reaction can be 50°C, 60°C, 70°C, 80°C, 90°C or 100°C, and the stirring time can be controlled to 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1.0h according to the reaction process.
[0043] As an optional embodiment, the step of adding a coprecipitant to the lithium-containing sodium aluminate solution to obtain a mixed solution specifically comprises:
[0044] A coprecipitant and a stabilizer are added to the lithium-containing sodium aluminate solution to obtain a mixed solution; the stabilizer is mannitol and / or sorbitol.
[0045] In the above embodiment, mannitol and / or sorbitol are added as stabilizers to the mixed solution, which can stabilize the aluminate solution, promote the precipitation of lithium aluminum hydrotalcite, reduce the precipitation of aluminum hydroxide, and make the lithium-rich precipitate have better purity, more stability, and fewer impurities. In the above embodiment, mannitol, sorbitol, or a mixture of mannitol and sorbitol can be selected as a stabilizer and added to the mixed solution.
[0046] As an optional implementation manner, in the mixed solution, the concentration of the mannitol and / or sorbitol is 1 ppm to 10 ppm.
[0047] In the above embodiment, the concentration of mannitol and / or sorbitol in the mixed solution is controlled to be 1ppm to 10ppm, which can avoid affecting the precipitation effect due to the concentration of mannitol and / or sorbitol being too high or too low. If the concentration of mannitol and / or sorbitol is higher than 10ppm, the viscosity of the sodium aluminate solution is affected, which is not conducive to the precipitation of lithium aluminum hydrotalcite; if the concentration of mannitol and / or sorbitol is lower than 1ppm, the sodium aluminate solution is easy to decompose, and the lithium-rich solid phase contains more aluminum hydroxide, and the lithium content is reduced. Exemplarily, the concentration of mannitol and / or sorbitol in the mixed solution is controlled to be 1ppm, 2ppm, 3ppm, 4ppm, 5ppm, 6ppm, 7ppm, 8ppm, 9ppm or 10ppm.
[0048] As an optional implementation, the mixed slurry is subjected to solid-liquid separation to obtain a lithium-rich solid phase, specifically comprising:
[0049] The mixed slurry is filtered to obtain a solid phase material; the solid phase material is washed with hot water to obtain a lithium-rich solid phase.
[0050] In the above embodiment, the mixed slurry contains lithium aluminum hydrotalcite precipitate and sodium aluminate solution. The solid phase material obtained after filtration is lithium aluminum hydrotalcite. After washing with hot water, the impurities attached to the lithium aluminum hydrotalcite precipitate are dissolved in hot water. The lithium-rich solid phase finally obtained has almost no impurities and is clean in composition.
[0051] As an optional implementation, the mixed slurry is subjected to solid-liquid separation, and the solid-liquid separation equipment may be a belt filter, a plate and frame filter press, a vertical filter press or a leaf filter.
[0052] As an optional implementation manner, the temperature of the hot water is 80°C to 100°C.
[0053] In the above embodiment, the solubility of impurities in hot water is greater. Exemplarily, the temperature of the hot water can be set to 80°C, 85°C, 90°C, 95°C or 100°C.
[0054] As an optional embodiment, the compound containing carbonate and / or bicarbonate is carbonate and / or bicarbonate.
[0055] In the above embodiment, the carbonate / bicarbonate includes sodium carbonate, ammonium carbonate, potassium carbonate or at least one of sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, or a mixture of carbonate and bicarbonate.
[0056] As an optional embodiment, the coprecipitant is a saturated solution containing carbonate and / or a saturated solution containing bicarbonate.
[0057] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.
[0058] Example 1
[0059] This embodiment provides a method for recovering lithium from a sodium aluminate solution, using sodium carbonate as a coprecipitant, comprising the following steps:
[0060] S1, obtaining a lithium-containing sodium aluminate solution;
[0061] S2, prepare saturated solution of sodium carbonate;
[0062] S3, adding a saturated sodium carbonate solution and a stabilizer mannitol to the lithium-containing sodium aluminate solution and mixing to obtain a mixed solution;
[0063] S4, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in the solid precipitate;
[0064] The molar ratio of carbonate ions to lithium ions in the mixed solution is 1:2, the dosage of mannitol is 3 ppm; the temperature of the coprecipitation reaction is 50° C.; the coprecipitation reaction time is 1 h;
[0065] S5. After the reaction is completed, solid-liquid separation and washing are performed, and the solid is a lithium-rich solid phase; the filtrate is a lithium-depleted sodium aluminate solution.
[0066] The lithium-rich solid phase in this embodiment was tested and calculated to obtain a lithium precipitation rate of 99% in this embodiment.
[0067] Example 2
[0068] This embodiment provides a method for recovering lithium from a sodium aluminate solution, using potassium carbonate as a coprecipitant, comprising the following steps:
[0069] S1, obtaining a lithium-containing sodium aluminate solution;
[0070] S2, prepare saturated solution of potassium carbonate;
[0071] S3, adding a saturated potassium carbonate solution and a stabilizer sorbitol to the lithium-containing sodium aluminate solution to obtain a mixed solution;
[0072] S4, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in the solid precipitate;
[0073] The molar ratio of carbonate ions to lithium ions in the mixed solution is 4:5, and the dosage concentration of sorbitol is 8 ppm;
[0074] The coprecipitation reaction temperature is 60°C; the coprecipitation reaction time is 0.8h;
[0075] S4. After the reaction is completed, solid-liquid separation and washing are carried out, and the solid is a lithium-rich solid phase; the filtrate is the delithiumated sodium aluminate solution.
[0076] The lithium-rich solid phase in this embodiment was tested and calculated to obtain a lithium precipitation rate of 98% in this embodiment.
[0077] Example 3
[0078] This embodiment provides a method for recovering lithium from a sodium aluminate solution, using ammonium carbonate as a coprecipitant, comprising the following steps:
[0079] S1, obtaining a lithium-containing sodium aluminate solution;
[0080] S2, prepare saturated ammonium carbonate solution;
[0081] S3, adding a saturated ammonium carbonate solution to a lithium-containing sodium aluminate solution to obtain a mixed solution;
[0082] S4, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in the solid precipitate;
[0083] The molar ratio of carbonate ions to lithium ions in the mixed solution is 1:1, the coprecipitation reaction temperature is 70° C., and the coprecipitation reaction time is 0.7 h.
[0084] S5. After the reaction is completed, solid-liquid separation and washing are performed, and the solid is a lithium-rich solid phase; the filtrate is a lithium-depleted sodium aluminate solution.
[0085] The lithium-rich solid phase in this embodiment was tested and calculated to obtain a lithium precipitation rate of 97% in this embodiment.
[0086] Example 4
[0087] This embodiment provides a method for recovering lithium from a sodium aluminate solution, using a mixture of sodium bicarbonate and sodium carbonate as a coprecipitant, comprising the following steps:
[0088] S1, obtaining a lithium-containing sodium aluminate solution;
[0089] S2, prepare saturated solutions of sodium carbonate and sodium bicarbonate;
[0090] S3, adding saturated sodium carbonate and sodium bicarbonate solutions to the lithium-containing sodium aluminate solution, mixing and heating, and performing a coprecipitation reaction to enrich lithium in the solid precipitate;
[0091] The molar ratio of carbonate ions and bicarbonate ions to lithium ions in the mixed solution is 2:3, the coprecipitation reaction temperature is 80°C, and the coprecipitation reaction time is 0.6h;
[0092] S4. After the reaction is completed, solid-liquid separation and washing are carried out, and the solid is a lithium-rich solid phase; the filtrate is the delithiumated sodium aluminate solution.
[0093] The lithium-rich solid phase in this embodiment was tested and calculated to obtain a lithium precipitation rate of 96% in this embodiment.
[0094] Example 5
[0095] This embodiment provides a method for recovering lithium from a sodium aluminate solution, wherein the coprecipitant used is sodium carbonate, and the method comprises the following steps:
[0096] S1, obtaining a lithium-containing sodium aluminate solution;
[0097] S2, prepare saturated solution of sodium carbonate;
[0098] S3, adding a saturated sodium carbonate solution to a lithium-containing sodium aluminate solution to obtain a mixed solution;
[0099] S4, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in a solid precipitate;
[0100] The molar ratio of carbonate ions to lithium ions in the mixed solution is 2:1, the coprecipitation reaction temperature is 90° C., and the coprecipitation reaction time is 0.5 h.
[0101] S4. After the reaction is completed, solid-liquid separation and washing are carried out, and the solid is a lithium-rich solid phase; the filtrate is the delithiumated sodium aluminate solution.
[0102] The lithium-rich solid phase in this embodiment was tested and calculated to have a lithium precipitation rate of 95.5%.
[0103] Example 6
[0104] This embodiment provides a method for recovering lithium from a sodium aluminate solution, wherein the coprecipitant used is ammonium bicarbonate, and the method comprises the following steps:
[0105] S1, obtaining a lithium-containing sodium aluminate solution;
[0106] S2, prepare saturated ammonium bicarbonate solution;
[0107] S3, adding a saturated ammonium bicarbonate solution to the lithium-containing sodium aluminate solution to obtain a mixed solution;
[0108] S4, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in the solid precipitate;
[0109] The molar ratio of bicarbonate ions to lithium ions in the mixed solution is 1:2, the coprecipitation reaction temperature is 50° C., and the coprecipitation reaction time is 1 h.
[0110] S5. After the reaction is completed, solid-liquid separation and washing are performed, and the solid is a lithium-rich solid phase; the filtrate is a lithium-depleted sodium aluminate solution.
[0111] The lithium-rich solid phase in this embodiment was tested and calculated to obtain a lithium precipitation rate of 98% in this embodiment.
[0112] Example 7
[0113] This embodiment provides a method for recovering lithium from a sodium aluminate solution, wherein the coprecipitant used is sodium bicarbonate, and the method comprises the following steps:
[0114] S1, obtaining a lithium-containing sodium aluminate solution;
[0115] S2, prepare a saturated solution of potassium bicarbonate;
[0116] S3, adding a saturated potassium bicarbonate solution to the lithium-containing sodium aluminate solution to obtain a mixed solution;
[0117] S4, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in a solid precipitate;
[0118] The molar ratio of bicarbonate ions to lithium ions in the mixed solution is 2:1, the temperature of the coprecipitation reaction is 100° C., and the coprecipitation reaction time is 0.5 h.
[0119] S5. After the reaction is completed, solid-liquid separation and washing are performed, and the solid is a lithium-rich solid phase; the filtrate is a lithium-depleted sodium aluminate solution.
[0120] The lithium-rich solid phase in this embodiment was tested and calculated to obtain a lithium precipitation rate of 97% in this embodiment.
[0121] Example 8
[0122] This embodiment provides a method for recovering lithium from a sodium aluminate solution, using potassium bicarbonate as a coprecipitant, comprising the following steps:
[0123] S1, obtaining a lithium-containing sodium aluminate solution;
[0124] S2, prepare a saturated solution of potassium bicarbonate;
[0125] S3, adding a saturated potassium bicarbonate solution to the lithium-containing sodium aluminate solution to obtain a mixed solution;
[0126] S4, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in the solid precipitate;
[0127] The molar ratio of bicarbonate ions to lithium ions in the mixed solution is 3:2, the coprecipitation reaction temperature is 85°C, and the coprecipitation reaction time is 0.8h;
[0128] S5. After the reaction is completed, solid-liquid separation and washing are performed, and the solid is a lithium-rich solid phase; the filtrate is a lithium-depleted sodium aluminate solution.
[0129] The lithium-rich solid phase in this embodiment was tested and calculated to obtain a lithium precipitation rate of 98% in this embodiment.
[0130] Comparative Example
[0131] This comparative example provides a method for recovering lithium from a sodium aluminate solution, using sodium carbonate as a coprecipitant, comprising the following steps:
[0132] S1, obtaining a lithium-containing sodium aluminate solution;
[0133] S2, adding the sodium carbonate solution to the lithium-containing sodium aluminate solution to obtain a mixed solution;
[0134] S3, stirring and heating the mixed solution to perform a coprecipitation reaction to enrich lithium in the solid precipitate;
[0135] The molar ratio of bicarbonate ions to lithium ions in the mixed solution is 1:3, the coprecipitation reaction temperature is 85°C, and the coprecipitation reaction time is 0.8h;
[0136] S4. After the reaction is completed, no stable precipitate exists.
[0137] In summary, the method for recovering lithium from sodium aluminate solution provided by the present invention is adopted, a sufficient amount of a compound containing carbonate and / or bicarbonate is added to the sodium aluminate solution, the carbonate or bicarbonate ions therein react with the lithium ions and aluminate ions in the sodium aluminate solution to coprecipitate and generate a lithium aluminum hydrotalcite solid precipitate, sorbitol or mannitol is added as a stabilizer, so that the solid precipitate is stable in form and not easy to decompose, and the solid precipitate is directly subjected to solid-liquid separation to obtain a lithium-rich solid phase. If the amount of bicarbonate or carbonate is insufficient, it is precipitated in the solution in the form of lithium carbonate, but lithium carbonate cannot exist stably in the sodium aluminate solution, so the lithium cannot be completely precipitated as lithium carbonate.
[0138] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.
Claims
1. A method for recovering lithium from sodium aluminate solution, characterized in that: The sodium aluminate solution contains lithium and comprises the following steps: adding a coprecipitant to a sodium aluminate solution containing lithium to obtain a mixed solution; The mixed solution is subjected to a coprecipitation reaction under heating and stirring conditions to obtain a mixed slurry; and Performing solid-liquid separation on the mixed slurry to obtain a lithium-rich solid phase; Wherein, the coprecipitant is a compound containing carbonate and / or bicarbonate.
2. The method for recovering lithium from sodium aluminate solution according to claim 1, characterized in that: In the mixed solution, the ratio of the molar concentration of the carbonate and / or bicarbonate to the molar concentration of the lithium ions is 1:2 to 2:
1.
3. The lithium recovery method for sodium aluminate solution according to claim 1 or 2, characterized in that: The heating temperature is 50° C. to 100° C., and the stirring time is 0.5 h to 1.0 h.
4. The method for recovering lithium from sodium aluminate solution according to claim 1, characterized in that: The step of adding a coprecipitant to the sodium aluminate solution containing lithium to obtain a mixed solution specifically comprises: Adding a coprecipitant and a stabilizer to the lithium-containing sodium aluminate solution to obtain a mixed solution; The stabilizer is mannitol and / or sorbitol.
5. The method for recovering lithium from sodium aluminate solution according to claim 4, characterized in that: In the mixed solution, the concentration of mannitol and / or sorbitol is 1 ppm to 10 ppm.
6. The method for recovering lithium from sodium aluminate solution according to claim 1, characterized in that: The solid-liquid separation of the mixed slurry to obtain a lithium-rich solid phase specifically includes: Performing solid-liquid separation on the mixed slurry to obtain a solid phase substance; The solid phase material is washed with hot water to obtain a lithium-rich solid phase.
7. The method for recovering lithium from sodium aluminate solution according to claim 6, characterized in that: The temperature of the hot water is 80°C to 100°C.
8. The coprecipitant for lithium recovery from sodium aluminate solution according to claim 1, characterized in that: The coprecipitant is carbonate and / or bicarbonate.
9. The coprecipitant for lithium recovery from sodium aluminate solution according to claim 8, characterized in that: The coprecipitant is a saturated solution containing carbonate and / or a saturated solution containing bicarbonate.