Method for recovering lithium in lithium precipitation mother liquor

Abstract

The invention relates to a method for recycling lithium in lithium precipitation mother liquor, and belongs to the technical field of lithium recycling. The method comprises the following steps: carrying out first mixing on lithium precipitation mother liquor and alkali to obtain a first mixed solution; carrying out second mixing on the first mixed solution and aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide; at a set temperature, heating and stirring the second mixed solution containing amorphous aluminum hydroxide to obtain a third mixed solution containing lithium aluminum water stone; carrying out solid-liquid separation on the third mixed solution containing the lithium aluminum stone to obtain the lithium aluminum stone; and washing and drying the lithium aluminum water stone in sequence to obtain a lithium aluminum water stone product. According to the method, lithium in the lithium precipitation mother liquor is recycled, and the weight of Li2O in the lithium aluminum water stone product is 6%-8%.

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 lithium precipitation mother liquor. Background Art

[0002] Lithium carbonate is widely used in emerging application fields such as batteries, lubricants, refrigerants, nuclear industry and optoelectronics industry. The preparation method of battery-grade lithium carbonate generally uses Li2SO4 or LiCl as raw materials, supplements with carbon source (sodium carbonate or carbon dioxide) to carbonize lithium, and obtains lithium carbonate and lithium precipitation mother liquor after solid-liquid separation. However, due to the solubility of lithium carbonate and the occurrence of other side reactions, the Li + About 1-2g / L. If the lithium in the lithium precipitation mother liquor is not recovered, the lithium will enter the next lithium precipitation cycle with the reaction. The longer the cycle route, the greater the loss of lithium. Therefore, solving the problem of lithium precipitation mother liquor recovery is the key to improving the lithium recovery rate.

[0003] At present, the lithium recovery from lithium precipitation mother liquor is usually carried out by acidification-evaporation concentration or low-temperature freezing to precipitate sodium sulfate, and then add carbon source to precipitate lithium carbonate, thereby improving the lithium recovery rate. However, the use of such traditional processes not only has many processes, high costs and high energy consumption, but also has a low lithium recovery rate. Summary of the invention

[0004] The present application provides a method for recovering lithium from a lithium precipitation mother liquor to solve the following technical problem: providing a new method for recovering lithium from a lithium precipitation mother liquor.

[0005] In a first aspect, the present application provides a method for recovering lithium from a lithium precipitation mother liquor, the method comprising:

[0006] Mixing the lithium precipitation mother solution with alkali to obtain a first mixed solution;

[0007] Mixing the first mixed solution with an aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide;

[0008] The second mixed solution containing amorphous aluminum hydroxide is heated and stirred at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide.

[0009] Optionally, the set temperature is 75°C to 95°C.

[0010] Optionally, the heating time is 1 h to 6 h.

[0011] Optionally, the stirring speed is 100 r / min to 300 r / min.

[0012] Optionally, the alkali includes at least one of the following: urea, ammonia water, sodium hydroxide, and potassium hydroxide.

[0013] Optionally, the aluminum salt includes at least one of the following: aluminum nitrate, aluminum chloride, and aluminum sulfate.

[0014] Optionally, the molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is (1-3):(6-20):1.

[0015] Optionally, the molar concentration of lithium ions in the lithium precipitation mother solution is 0.06 mol / L to 0.30 mol / L.

[0016] Optionally, the second mixed solution containing amorphous aluminum hydroxide is heated and stirred at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide, and then further comprising:

[0017] The third mixed solution containing lithium aluminum hydrate is subjected to solid-liquid separation to obtain lithium aluminum hydrate;

[0018] The lithium aluminum hydrate is washed and dried in sequence to obtain a lithium aluminum hydrate product.

[0019] Optionally, the washing temperature is 80°C to 90°C;

[0020] and / or,

[0021] The drying temperature is 80°C to 120°C.

[0022] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0023] The method for recovering lithium from the lithium precipitation mother liquor provided in the embodiment of the present application comprises: first mixing the lithium precipitation mother liquor with alkali to obtain a first mixed solution; second mixing the first mixed solution with aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide; heating and stirring the second mixed solution containing amorphous aluminum hydroxide at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide. The first mixing of the lithium precipitation mother liquor with the alkali can dissolve and disperse the alkali in the lithium precipitation mother liquor, and the alkali fully ionizes hydroxide ions in the lithium precipitation mother liquor; the second mixing of the first mixed solution with the aluminum salt can promote the hydrolysis reaction of the aluminum salt to generate amorphous aluminum hydroxide under the action of the hydroxide ions in the first mixed solution, and the amorphous aluminum hydroxide has a large specific surface area and a high reaction activity, and has a certain adsorption effect; the amorphous aluminum hydroxide can be used as an adsorption matrix, and at a set temperature, the amorphous aluminum hydroxide can stably adsorb Li in the second mixed solution. + 、CO3 2- , Cl - 、SO4 2- OH -Plasma, these ions interact with amorphous aluminum hydroxide and gradually transform into lithium aluminum hydrate, thus providing a new method for the recovery of lithium from lithium precipitation mother liquor, thereby improving the comprehensive recovery rate 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 following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. 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 schematic flow chart of a method for recovering lithium from a lithium precipitation mother liquor 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 the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present specification, the terms "including", "comprising", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second" 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. "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 and B can be singular or plural. In this article, "at least one" means one or more, and "plural" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, the mass ratio of substance A, substance B, and substance C is 1:2:3, then substance A, substance B, and substance C should correspond one-to-one with the proportional numbers in the proportional formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[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] In a first aspect, the present application provides a method for recovering lithium from lithium precipitation mother liquor. Figure 1 A schematic diagram of a method for recovering lithium from a lithium precipitation mother liquor provided in an embodiment of the present application; see Figure 1 , the method comprising:

[0032] S1, mixing the lithium precipitation mother solution with alkali to obtain a first mixed solution;

[0033] In some embodiments, the base includes at least one of urea, aqueous ammonia, sodium hydroxide, and potassium hydroxide.

[0034] In the present embodiment, the lithium precipitation mother liquor is the liquid remaining after the lithium precipitation step in the lithium salt production process. In the lithium salt extraction process, lithium ions are usually precipitated in the form of a lithium salt (such as lithium carbonate) by adding a precipitant (such as sodium carbonate), and the remaining solution containing multiple components is the lithium precipitation mother liquor, which generally contains Li + 、CO3 2- , Cl - 、SO4 2- Plasma. The lithium precipitation mother liquor is first mixed with the alkali, so that the lithium precipitation mother liquor dissolves and disperses the alkali, and the alkali fully ionizes hydroxide ions in the lithium precipitation mother liquor. Exemplarily, the alkali can be a combination of one or more of urea, ammonia water, sodium hydroxide, and potassium hydroxide.

[0035] S2, performing a second mixing of the first mixed solution and an aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide;

[0036] In some embodiments, the aluminum salt comprises at least one of the following: aluminum nitrate, aluminum chloride, aluminum sulfate.

[0037] In an embodiment of the present application, under the action of hydroxide ions in the first mixed solution, the aluminum salt is prompted to undergo a hydrolysis reaction to generate amorphous aluminum hydroxide, which has a large specific surface area and a high reactivity. Amorphous aluminum hydroxide has no regular crystal structure and is a highly dispersed colloidal substance. Since amorphous aluminum hydroxide has no regular crystal structure, it is composed of many tiny particles aggregated, and the particle size and shape are irregular, which makes it have abundant surface atoms and unsaturated bonds. These surface atoms and unsaturated bonds have high energy and can interact with substances in the surrounding environment, thereby producing adsorption, which may be electrostatic adsorption, physical adsorption-intermolecular forces, and chemical adsorption to form chemical bonds. One or more. Exemplary, the aluminum salt can be a combination of one or more of aluminum nitrate, aluminum chloride, and aluminum sulfate, and the aluminum salt can contain water of crystallization.

[0038] In some embodiments, the molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the base, and aluminum ions in the aluminum salt is (1-3):(6-20):1.

[0039] In the embodiment of the present application, an appropriate amount of hydroxide ions can ensure that the aluminum salt is fully hydrolyzed to form amorphous aluminum hydroxide, and avoid the phenomenon of amorphous aluminum hydroxide dissolving, thereby stably providing a matrix for the subsequent adsorption of lithium ions, thereby improving the lithium precipitation rate, and the amorphous aluminum hydroxide has a certain adsorption capacity, thereby adsorbing the corresponding lithium ions to ensure the lithium precipitation rate. The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions of the alkali, and aluminum ions of the aluminum salt can be (1-3): (6-20): 1, and the reactants can play a good synergistic role. Amorphous aluminum hydroxide can fully adsorb lithium ions and enrich them from the lithium precipitation mother solution. After the set temperature heating phase transition process, lithium aluminum water stone is generated, thereby effectively reducing the residual lithium ions in the lithium precipitation mother solution, so that lithium can be recovered in the form of lithium aluminum water stone, and the efficiency of recovering lithium from the lithium precipitation mother solution is improved. For example, the molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali, and aluminum ions in the aluminum salt can be 1:6:1, 1:20:1, 1:10:1, 3:10:1, 2:10:1, 2:15:1, 2:12:1, 3:8:1, etc.

[0040] In some embodiments, the molar concentration of lithium ions in the lithium precipitation mother solution is 0.06 mol / L to 0.30 mol / L.

[0041] In an embodiment of the present application, the molar concentration of lithium ions in the lithium precipitation mother solution can be 0.06mol / L, 0.08mol / L, 0.10mol / L, 0.13mol / L, 0.15mol / L, 0.18mol / L, 0.20mol / L, 0.23mol / L, 0.25mol / L, 0.28mol / L, 0.30mol / L, etc.

[0042] S3. At a set temperature, the second mixed solution containing amorphous aluminum hydroxide is heated and stirred to obtain a third mixed solution containing lithium aluminum hydroxide.

[0043] In some embodiments, the set temperature is 75°C to 95°C.

[0044] In some embodiments, the heating time is 1 h to 6 h.

[0045] In the embodiment of the present application, the amorphous aluminum hydroxide can be used as an adsorption matrix, and at a set temperature, the amorphous aluminum hydroxide can stably adsorb Li in the second mixed solution. + 、CO3 2- , Cl - 、SO4 2- OH -Plasma, these ions interact with amorphous aluminum hydroxide, gradually transforming into lithium aluminum water stone, thereby improving the recovery rate of lithium in lithium precipitation mother liquor. "Set temperature" refers to the heating temperature, which can be set at 75℃~95℃, so that amorphous aluminum hydroxide can fully absorb Li + 、CO3 2- , Cl - 、SO4 2- OH - Plasma, and phase transformation occurs to generate lithium aluminum water stone, and the corresponding heating time is matched, and the heating time can be 1h to 6h, so as to give sufficient time for phase transformation to generate lithium aluminum water stone, thereby ensuring the recovery rate of lithium in the lithium precipitation mother liquor. Exemplarily, the set temperature can be 75°C, 78°C, 80°C, 83°C, 85°C, 88°C, 90°C, 93°C, 95°C, etc., and the heating time can be 1h, 2h, 3h, 4h, 5h, 6h, etc.

[0046] In some embodiments, the stirring speed is 100 r / min to 300 r / min.

[0047] In the embodiment of the present application, the stirring speed can be 100r / min to 300r / min, which can stabilize the structure of amorphous aluminum hydroxide and ensure the adsorption efficiency of amorphous aluminum hydroxide. If the stirring speed is higher than 300r / min, the shear force generated by rapid stirring may continuously destroy the growing structure on the surface of the crystal nucleus of amorphous aluminum hydroxide, making it difficult for the crystal nucleus to grow, resulting in a finer particle size of the generated amorphous aluminum hydroxide, thereby causing the subsequent lithium aluminum water stone to be difficult to separate from the solid and liquid; if the stirring speed is lower than 100r / min, the fluidity of the second solution is weak, which may cause the aluminum hydroxide particles to gradually settle under the action of gravity to form aluminum hydroxide precipitation, thereby causing the adsorption rate of amorphous aluminum hydroxide to decrease, and then the recovery rate of lithium to decrease. Exemplarily, the stirring speed can be 100r / min, 130r / min, 150r / min, 180r / min, 200r / min, 230r / min, 250r / min, 280r / min, 300r / min, etc.

[0048] In some embodiments, the second mixed solution containing amorphous aluminum hydroxide is heated and stirred at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide, and then further comprises:

[0049] S4, performing solid-liquid separation on the third mixed solution containing lithium aluminum hydrate to obtain lithium aluminum hydrate;

[0050] S5, washing and drying the lithium aluminum hydrate in sequence to obtain a lithium aluminum hydrate product.

[0051] In some embodiments, the washing temperature is 80°C to 90°C;

[0052] and / or,

[0053] The drying temperature is 80°C to 120°C.

[0054] In the embodiment of the present application, the third mixed solution containing lithium aluminum water stone is subjected to solid-liquid separation to obtain lithium aluminum water stone; the lithium aluminum water stone is washed and dried in sequence to obtain a lithium aluminum water stone product; the washing temperature can be 80°C to 90°C to fully remove the sodium ions in the lithium aluminum water stone. Exemplarily, the washing temperature can be 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, etc.; the drying temperature can be 80°C to 120°C, and the water in the lithium aluminum water stone can be removed. Exemplarily, the drying temperature can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, etc. The drying time can be 12h to 24h. The lithium aluminum water stone product is a lithium concentrate, and the weight of Li2O in the lithium aluminum water stone product is 6% to 8%, and the lithium aluminum water stone product can be directly used for industrial lithium extraction.

[0055] In summary, the method for recovering lithium from lithium precipitation mother liquor provided in the embodiment of the present application has the following advantages:

[0056] 1. The alkali is dissolved and dispersed in the lithium precipitation mother liquor, so that the alkali is fully ionized in the lithium precipitation mother liquor to produce hydroxide ions. This step creates an alkaline environment for the subsequent aluminum salt hydrolysis reaction;

[0057] 2. The first mixed solution containing a large amount of hydroxide ions promotes the hydrolysis reaction of aluminum salt to generate amorphous aluminum hydroxide. The formation of amorphous aluminum hydroxide is because during the hydrolysis reaction, hydroxide ions quickly combine with aluminum ions, and without enough time to form a regular crystal structure, this disordered aluminum hydroxide is generated. It has a large specific surface area and high reactivity. This is because its amorphous structure leads to more surface atoms and unsaturated bonds, which makes it have a strong adsorption capacity;

[0058] 3. Amorphous aluminum hydroxide is used as an adsorption matrix to adsorb Li + 、CO3 2- , Cl - 、SO4 2- OH - The ions are adsorbed by the plasma. After being adsorbed, they interact with amorphous aluminum hydroxide and gradually transform into lithium aluminum hydroxide. The phase transformation process involves the rearrangement of ions and the formation of chemical bonds. It is a complex physical and chemical change process, which ultimately achieves the enrichment of lithium and the improvement of recovery rate.

[0059] 4. The set temperature of heating and the stirring conditions promote the phase transition to form lithium aluminum hydrate. The set temperature of heating makes the movement of ions more active, which is conducive to the continuation of the adsorption process and the occurrence of phase transition reaction; stirring ensures the uniformity of the solution, so that the ions can fully contact with the amorphous aluminum hydroxide, promoting the formation of lithium aluminum hydrate; this phase transition process transfers lithium ions from the solution to lithium aluminum hydrate, realizing the effective enrichment of lithium, thereby providing a new method for the recovery of lithium from lithium precipitation mother liquor.

[0060] 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 the unrecorded specific conditions in the following examples are usually measured according to national standards. If there is no corresponding national standard, then carry out according to general international standards, normal conditions or according to the conditions recommended by the manufacturer.

[0061] Example 1

[0062] A method for recovering lithium from lithium precipitation mother liquor, specifically comprising:

[0063] S11, mixing the lithium ion mother solution with the alkali to obtain a first mixed solution; wherein the lithium ion concentration of the lithium ion mother solution is 0.15 mol / L, the lithium ion mother solution is 1 L, the alkali is urea, and the weight of urea is 72 g;

[0064] S21, performing a second mixing of the first mixed solution and the aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide; wherein the aluminum salt is aluminum nitrate nonahydrate, and the weight of the aluminum nitrate nonahydrate is 68 g;

[0065] The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is 1:12:1;

[0066] S31, heating and stirring the second mixed solution containing amorphous aluminum hydroxide at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide; wherein the set temperature is 95° C., the heating time is 6 hours, and the stirring speed is 300 r / min; S41, performing solid-liquid separation on the third mixed solution containing lithium aluminum hydroxide to obtain lithium aluminum hydroxide and a filtrate;

[0067] S51, washing and drying the lithium aluminum hydrate in sequence to obtain a lithium aluminum hydrate product; wherein, washing is performed with 95° C. deionized water and drying is performed in a forced air drying oven at 120° C. for 12 hours.

[0068] Example 2

[0069] A method for recovering lithium from lithium precipitation mother liquor, specifically comprising:

[0070] S12, mixing the lithium ion mother solution with the alkali to obtain a first mixed solution; wherein the lithium ion concentration of the lithium ion mother solution is 0.30 mol / L, the lithium ion mother solution is 1 L, the alkali is sodium hydroxide, and the weight of the sodium hydroxide is 72 g;

[0071] S22, performing a second mixing of the first mixed solution and the aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide; wherein the aluminum salt is aluminum chloride hexahydrate, and the weight of the aluminum chloride hexahydrate is 72 g;

[0072] The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is 3:6:1;

[0073] S32, heating and stirring the second mixed solution containing amorphous aluminum hydroxide at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide; wherein the set temperature is 80° C., the heating time is 1 hour, and the stirring speed is 100 r / min; S42, performing solid-liquid separation on the third mixed solution containing lithium aluminum hydroxide to obtain lithium aluminum hydroxide and a filtrate;

[0074] S52, washing and drying the lithium aluminum hydrate stone in sequence to obtain a lithium aluminum hydrate stone product; wherein, washing is performed with 95° C. deionized water and drying is performed in a forced air drying oven at 80° C. for 24 hours.

[0075] Example 3

[0076] A method for recovering lithium from lithium precipitation mother liquor, specifically comprising:

[0077] S13, mixing the lithium precipitation mother solution with the alkali for the first time to obtain a first mixed solution; wherein the lithium ion concentration of the lithium precipitation mother solution is 0.10 mol / L, the lithium precipitation mother solution is 1 L, and the alkali is 285 ml of ammonia water with a mass fraction of 50%;

[0078] S23, performing a second mixing of the first mixed solution and the aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide; wherein the aluminum salt is aluminum sulfate hexahydrate, and the weight of the aluminum sulfate hexahydrate is 68 g;

[0079] The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is 1:20:1;

[0080] S33, heating and stirring the second mixed solution containing amorphous aluminum hydroxide at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide; wherein the set temperature is 85° C., the heating time is 3 hours, and the stirring speed is 200 r / min; S43, performing solid-liquid separation on the third mixed solution containing lithium aluminum hydroxide to obtain lithium aluminum hydroxide and a filtrate;

[0081] S53, washing and drying the lithium aluminum hydrate in sequence to obtain a lithium aluminum hydrate product; wherein, washing is performed with 95° C. deionized water and drying is performed in a forced air drying oven at 120° C. for 12 hours.

[0082] Example 4

[0083] A method for recovering lithium from lithium precipitation mother liquor, specifically comprising:

[0084] S14, mixing the lithium ion mother solution with the alkali to obtain a first mixed solution; wherein the lithium ion concentration of the lithium ion mother solution is 0.20 mol / L, the lithium ion mother solution is 1 L, the alkali is potassium hydroxide, and the weight of potassium hydroxide is 112 g;

[0085] S24, performing a second mixing of the first mixed solution and the aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide; wherein the aluminum salt is aluminum chloride hexahydrate, and the weight of the aluminum chloride hexahydrate is 96 g;

[0086] The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is 1:10:1;

[0087] S34, heating and stirring the second mixed solution containing amorphous aluminum hydroxide at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide; wherein the set temperature is 90° C., the heating time is 2 hours, and the stirring speed is 300 r / min; S44, performing solid-liquid separation on the third mixed solution containing lithium aluminum hydroxide to obtain lithium aluminum hydroxide and a filtrate;

[0088] S54, washing and drying the lithium aluminum hydrate in sequence to obtain a lithium aluminum hydrate product; wherein, washing is performed with 85° C. deionized water and drying is performed in a forced air drying oven at 120° C. for 12 hours.

[0089] Example 5

[0090] A method for recovering lithium from lithium precipitation mother liquor, specifically comprising:

[0091] S15, mixing the lithium ion mother solution with the alkali to obtain a first mixed solution; wherein the lithium ion concentration of the lithium ion mother solution is 0.20 mol / L, the lithium ion mother solution is 1 L, the alkali is sodium hydroxide, and the weight of the sodium hydroxide is 88 g;

[0092] S25, performing a second mixing of the first mixed solution and the aluminum salt to obtain a second mixed solution containing amorphous aluminum hydroxide; wherein the aluminum salt is aluminum chloride hexahydrate, and the weight of the aluminum chloride hexahydrate is 96 g;

[0093] The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is 1:11:1;

[0094] S35, heating and stirring the second mixed solution containing amorphous aluminum hydroxide at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide; wherein the set temperature is 95° C., the heating time is 6 hours, and the stirring speed is 100 r / min; S45, performing solid-liquid separation on the third mixed solution containing lithium aluminum hydroxide to obtain lithium aluminum hydroxide and a filtrate;

[0095] S55, washing and drying the lithium aluminum hydrate in sequence to obtain a lithium aluminum hydrate product; wherein, washing is performed with 95° C. deionized water and drying is performed in a forced air drying oven at 120° C. for 12 hours.

[0096] Comparative Example 1

[0097] Based on the disclosure of Example 5, the method for recovering lithium from lithium precipitation mother liquor provided in Comparative Example 1 comprises:

[0098] The lithium precipitation mother solution is mixed with aluminum salt to obtain a mixed solution; wherein the lithium ion concentration of the lithium precipitation mother solution is 0.20 mol / L, the lithium precipitation mother solution is 1 L, the aluminum salt is aluminum chloride hexahydrate, and the weight of aluminum chloride hexahydrate is 96 g;

[0099] The mixed solution was heated and stirred at a set temperature. After the heating was completed, no lithium aluminum water stone precipitate was obtained. The set temperature was 95° C., the heating time was 6 h, and the stirring speed was 100 r / min.

[0100] Comparative Example 2

[0101] Based on the disclosure of Example 4, the method for recovering lithium from lithium precipitation mother liquor provided in Comparative Example 2 comprises:

[0102] The lithium precipitation mother solution is first mixed with the alkali to obtain a first mixed solution; wherein the lithium ion concentration of the lithium precipitation mother solution is 0.20 mol / L, the lithium precipitation mother solution is 1 L, the alkali is potassium hydroxide, and the weight of the potassium hydroxide is 112 g;

[0103] The first mixed solution is mixed with an aluminum salt for a second time to obtain a second mixed solution containing amorphous aluminum hydroxide; wherein the aluminum salt is aluminum chloride hexahydrate, and the weight of the aluminum chloride hexahydrate is 48 g;

[0104] The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is 1:12:0.5;

[0105] At a set temperature, heating and stirring the second mixed solution containing amorphous aluminum hydroxide to obtain a third mixed solution containing lithium aluminum hydroxide; wherein the set temperature is 90° C., the heating time is 2 h, and the stirring speed is 300 r / min;

[0106] The third mixed solution containing lithium aluminum hydrate is subjected to solid-liquid separation to obtain lithium aluminum hydrate and a filtrate;

[0107] The lithium aluminum hydrate stone is washed and dried in sequence to obtain a lithium aluminum hydrate stone product; wherein, the lithium aluminum hydrate stone is washed with 85° C. deionized water and dried in a forced air drying oven at 120° C. for 12 hours.

[0108] The weight of Li2O in the lithium aluminum hydrate products obtained in Examples 1 to 5 and Comparative Examples 1 to 2 was tested, and the molar concentration of lithium ions in the filtrate was tested. The test results are shown in Table 1.

[0109] Table 1 Li2O weight in lithium aluminum hydrate product and molar concentration of lithium ions in filtrate

[0110]

[0111] As can be seen from Table 1, the method for recovering lithium from lithium precipitation mother liquor provided in the embodiment of the present application provides a new method for recovering lithium from lithium precipitation mother liquor, thereby improving the comprehensive recovery rate of lithium. By comparing Comparative Example 1 with Example 5, no alkali was added in Comparative Example 1, and ultimately lithium concentrate was not formed, and the recovery of lithium from lithium precipitation mother liquor was not achieved; by comparing Comparative Example 2 with Example 4, the amount of aluminum salt added in Comparative Example 2 was lower than the range of the embodiment of the present application, resulting in a low weight of Li2O in the lithium aluminum water stone product.

[0112] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:

[0113] (1) The large specific surface area and reactivity of amorphous aluminum hydroxide enable it to effectively adsorb ions in the solution, especially lithium ions. Compared with traditional recovery methods, amorphous aluminum hydroxide can capture lithium ions more efficiently and reduce the residual lithium ions in the solution, thus providing a new method for the recovery of lithium from lithium precipitation mother liquor;

[0114] (2) The method for recovering lithium from lithium precipitation mother liquor provided in the embodiment of the present application solves the problems in the prior art of high energy consumption of freezing and evaporation concentration, increased investment cost due to the addition of special equipment, and the need to circulate lithium precipitation mother liquor and washing liquid, and can greatly improve the comprehensive recovery rate of lithium;

[0115] (3) This technical solution has the advantages of short process flow, simplicity, low cost and high economic benefits.

[0116] 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 scope consistent with the principles and novel features applied for herein.

Claims

1. A method for recovering lithium from a lithium precipitation mother liquor, the method comprising: The lithium precipitation mother solution is first mixed with an alkali to obtain a first mixed solution; The first mixed solution is mixed with an aluminum salt for a second time to obtain a second mixed solution containing amorphous aluminum hydroxide; The second mixed solution containing amorphous aluminum hydroxide is heated and stirred at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide.

2. The method according to claim 1, characterized in that The set temperature is 75°C to 95°C.

3. The method according to claim 1 or 2, characterized in that: The heating time is 1 h to 6 h.

4. The method according to claim 1 or 2, characterized in that: The stirring speed is 100 r / min to 300 r / min.

5. The method according to claim 1, characterized in that The alkali includes at least one of the following: urea, ammonia water, sodium hydroxide, and potassium hydroxide.

6. The method according to claim 1, characterized in that The aluminum salt includes at least one of the following: aluminum nitrate, aluminum chloride, and aluminum sulfate.

7. The method according to claim 1, characterized in that The molar ratio of lithium ions in the lithium precipitation mother solution, hydroxide ions in the alkali and aluminum ions in the aluminum salt is (1-3):(6-20):

1.

8. The method according to claim 1, characterized in that The molar concentration of lithium ions in the lithium precipitation mother solution is 0.06 mol / L to 0.30 mol / L.

9. The method according to claim 1, characterized in that: After the second mixed solution containing amorphous aluminum hydroxide is heated and stirred at a set temperature to obtain a third mixed solution containing lithium aluminum hydroxide, the method further comprises: The third mixed solution containing lithium aluminum hydrate is subjected to solid-liquid separation to obtain lithium aluminum hydrate; The lithium aluminum hydrate is washed and dried in sequence to obtain a lithium aluminum hydrate product.

10. The method according to claim 9, characterized in that The washing temperature is 80°C to 90°C; and / or, The drying temperature is 80°C to 120°C.

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