Aluminum lithium adsorbent and preparation method thereof
Aluminum-doped lithium adsorbents were prepared by liquid-phase co-precipitation and spray drying, which solved the problems of cycle stability and clogging of aluminum-doped lithium adsorbents, and realized efficient lithium adsorption and low-cost industrial application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUASHENG FLUID SEPARATION TECH XIAMEN CO LTD
- Filing Date
- 2026-02-05
- Publication Date
- 2026-05-01
AI Technical Summary
Existing aluminum-based lithium adsorbents have high cycle stability and aluminum dissolution rate, but low utilization of active sites. Furthermore, the powdery materials produced during the preparation process are prone to clogging, making it difficult to achieve continuous industrial operation.
Porous spherical aluminum-based lithium adsorbents were prepared by liquid-phase co-precipitation. By doping with group IVB or group VIIB metal elements and combining with spray drying technology, regular spherical particles were formed, which enhanced the structural stability and mass transfer performance.
It improved lithium adsorption capacity, reduced aluminum dissolution rate, improved hydrodynamic performance, reduced preparation cost, and enabled continuous industrial operation.
Smart Images
Figure CN121944982A_ABST
Abstract
Description
An aluminum-based lithium adsorbent and its preparation method Technical Field
[0001] This invention belongs to the technical field of aluminum-based lithium adsorbents, and particularly relates to an aluminum-based lithium adsorbent and its preparation method. Background Technology
[0002] With the explosive growth of the new energy vehicle and energy storage industries, the global demand for lithium resources has increased dramatically. Salt lake brines are rich in lithium resources, but they are often characterized by a high magnesium-to-lithium ratio. Traditional precipitation methods are difficult to effectively separate lithium from magnesium. Adsorption methods, due to their high selectivity, environmental friendliness, and cost advantages, have become one of the mainstream technologies for lithium extraction from salt lakes with high magnesium-to-lithium ratios.
[0003] Among them, aluminum-based lithium adsorbents have attracted widespread attention due to their unique intercalation memory effect for lithium ions and the availability and low cost of raw materials. However, existing aluminum-based lithium adsorbents still face the following significant problems in practical industrial applications: poor cycle stability and high dissolution rate. When aluminum-based adsorbents undergo repeated adsorption-desorption cycles in the eluent, their layered structure is prone to collapse, and aluminum elements are easily lost. This not only shortens the service life of the adsorbent and increases production costs, but the dissolved aluminum ions also contaminate the downstream lithium-rich solution.
[0004] In existing technologies, unmodified adsorbents often exhibit high aluminum dissolution rates after multiple cycles, leading to rapid decay of adsorption capacity. Traditional aluminum-based adsorbents have low utilization rates of active sites, making it difficult to meet the growing demand for efficient lithium extraction. Some preparation processes employ solid-phase high-temperature co-firing or simple precipitation methods, resulting in products that are often irregularly shaped lumps or powders. When directly used in adsorption columns, these products exhibit high fluid resistance, are prone to clogging, and have uneven powder distribution, leading to low mass transfer efficiency and making it difficult to achieve continuous industrial operation. Although granulation and bonding techniques exist, the introduction of binders often obscures active sites, thus reducing adsorption performance and leaving room for improvement. Summary of the Invention
[0005] The purpose of this invention is to address the problem of low utilization rate of active sites in traditional aluminum-based adsorbents by proposing an aluminum-based lithium adsorbent and its preparation method.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] An aluminum-based lithium adsorbent, wherein the adsorbent is a spherical particle with a porous structure;
[0008] The adsorbent is prepared by mixing and co-precipitating lithium source, aluminum source and doped metal source in liquid phase, followed by granulation, sintering and acid washing activation.
[0009] Lix·Al(1-y)·My·(OH)3·nH2O;
[0010] Wherein, M is at least one metallic element selected from Group IVB and Group VIIB;
[0011] The value of x ranges from 0.5 to 1.2;
[0012] The value of y ranges from 0.005 to 0.10;
[0013] n is the number of moles of water of crystallization.
[0014] As a further description of the above technical solution:
[0015] The doped metal source is selected from at least one of titanium (Ti), zirconium (Zr), manganese (Mn) or tin (Sn).
[0016] As a further description of the above technical solution:
[0017] The adsorbent has a lithium saturation adsorption capacity ≥6.0 mg / g; after 10 adsorption-desorption cycles, its aluminum dissolution rate is ≤0.20%.
[0018] As a further description of the above technical solution:
[0019] A method for preparing a doped aluminum-based lithium adsorbent includes the following steps:
[0020] S1. Ingredient preparation: Dissolve the lithium source, aluminum source and doped metal source M in a solvent in a molar ratio to prepare a mixed salt solution (solution A).
[0021] S2, co-precipitation reaction: The mixed salt solution and the alkaline solution (B solution) are added to the reactor in parallel flow. Under stirring conditions, the pH value and reaction temperature of the system are controlled to carry out the co-precipitation reaction to obtain a slurry.
[0022] S3. Granulation and molding: The obtained slurry is aged and then dried and granulated by spray drying to obtain microsphere precursors.
[0023] S4. Sintering: The microsphere precursor is sintered and solidified at high temperature.
[0024] S5. Activation: The sintered product is washed with an acid solution to displace lithium ions. After washing with water and drying, the doped aluminum-based lithium adsorbent is obtained.
[0025] As a further description of the above technical solution:
[0026] The lithium source in S1 is lithium chloride, lithium nitrate or lithium sulfate;
[0027] The aluminum source is aluminum chloride, aluminum nitrate, or aluminum sulfate;
[0028] The doped metal source M is a chloride, nitrate, or sulfate of the corresponding metal;
[0029] In the mixed salt solution, the molar ratio of Li to (Al+M) is (0.8~1.2):2.0.
[0030] As a further description of the above technical solution:
[0031] The pH value in S2 is controlled within the range of 8.0 to 10.5; the reaction temperature is controlled within the range of 40°C to 90°C; and the alkaline solution is an aqueous solution of sodium hydroxide, potassium hydroxide, or ammonia.
[0032] As a further description of the above technical solution:
[0033] The aging temperature in S3 is 60℃~90℃, and the aging time is 4~12 hours.
[0034] As a further description of the above technical solution:
[0035] The sintering temperature in S4 is 400℃~700℃, and the sintering time is 1~5 hours.
[0036] As a further description of the above technical solution:
[0037] The acid solution in S5 is a hydrochloric acid solution with a concentration of 0.1~1.0 mol / L.
[0038] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:
[0039] 1. In this invention, the adsorption capacity can be effectively improved by doping. By introducing group IVB or group VIIB metal elements into the aluminum adsorbent lattice, and utilizing their similar ionic radius and different valence state to aluminum ions, appropriate lattice distortion or active vacancies are generated inside the crystal. This microstructure regulation effectively activates more lithium ion adsorption sites.
[0040] 2. In this invention, the introduction of doping elements enhances the stability of the adsorbent framework structure, inhibits the breaking of Al-O bonds during acid elution, effectively reduces aluminum dissolution rate, and gives the adsorbent a longer service life, thereby reducing industrial operating costs.
[0041] 3. In this invention, the excellent particle morphology and mass transfer performance are achieved through a combination of liquid-phase co-precipitation and spray drying processes. Compared to the solid-phase method, the liquid-phase method ensures the uniform distribution of dopant elements at the molecular level. Combined with spray drying technology, the resulting adsorbent exhibits regular spherical particles with a rich and interconnected porous structure on its surface. Optimizing the sphericity improves the hydrodynamic performance of the adsorbent in the adsorption column, resulting in low liquid flow resistance and less clogging. The porous structure increases the specific surface area, shortens the diffusion path of lithium ions, and improves the kinetic rates of adsorption and desorption.
[0042] 4. In this invention, co-precipitation technology is used. By precisely controlling the pH value and temperature of the reaction system, the uniformity of the precursor precipitation is ensured, and the continuity of dissolution, precipitation, spraying and sintering is good. Complex organic sols or expensive crosslinking agents are not used, avoiding complicated post-processing steps. The production efficiency is high, the product quality is stable, and the preparation cost is reduced. Attached Figure Description
[0043] Figure 1 is a flowchart of a method for preparing an aluminum-based lithium adsorbent proposed in this invention;
[0044] Figure 2 is a SEM image of the adsorbent particles in the preparation method of the aluminum-based lithium adsorbent proposed in this invention. Detailed Implementation
[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0046] Please refer to Figures 1-2. The present invention provides a technical solution: an aluminum-based lithium adsorbent, wherein the adsorbent is a spherical particle with a porous structure;
[0047] The adsorbent is prepared by mixing and co-precipitating lithium source, aluminum source and doped metal source in liquid phase, followed by granulation, sintering and acid washing activation.
[0048] Lix·Al(1-y)·My·(OH)3·nH2O;
[0049] Wherein, M is at least one metallic element selected from Group IVB and Group VIIB;
[0050] The value of x ranges from 0.5 to 1.2;
[0051] The value of y ranges from 0.005 to 0.10;
[0052] n is the number of moles of water of crystallization.
[0053] Furthermore, the doping metal source is selected from at least one of titanium (Ti), zirconium (Zr), manganese (Mn) or tin (Sn).
[0054] Furthermore, the lithium saturated adsorption capacity of the adsorbent is ≥6.0 mg / g; after 10 adsorption-desorption cycles, its aluminum dissolution rate is ≤0.20%.
[0055] Furthermore, a method for preparing a doped aluminum-based lithium adsorbent includes the following steps:
[0056] S1. Ingredient preparation: Dissolve the lithium source, aluminum source and doped metal source M in a solvent in a molar ratio to prepare a mixed salt solution (solution A).
[0057] S2, co-precipitation reaction: The mixed salt solution and the alkaline solution (B solution) are added to the reactor in parallel flow. Under stirring conditions, the pH value and reaction temperature of the system are controlled to carry out the co-precipitation reaction to obtain a slurry.
[0058] S3. Granulation and molding: The obtained slurry is aged and then dried and granulated by spray drying to obtain microsphere precursors.
[0059] S4. Sintering: The microsphere precursor is sintered and solidified at high temperature.
[0060] S5. Activation: The sintered product is washed with an acid solution to displace lithium ions. After washing with water and drying, the doped aluminum-based lithium adsorbent is obtained.
[0061] Furthermore, the lithium source in S1 is lithium chloride, lithium nitrate, or lithium sulfate;
[0062] The aluminum source is aluminum chloride, aluminum nitrate, or aluminum sulfate;
[0063] The doped metal source M is a chloride, nitrate, or sulfate of the corresponding metal;
[0064] In the mixed salt solution, the molar ratio of Li to (Al+M) is (0.8~1.2):2.0.
[0065] Furthermore, the pH value in S2 is controlled within the range of 8.0 to 10.5; the reaction temperature is controlled within the range of 40°C to 90°C; and the alkaline solution is an aqueous solution of sodium hydroxide, potassium hydroxide, or ammonia.
[0066] Furthermore, the aging temperature in S3 is 60℃~90℃, and the aging time is 4~12 hours.
[0067] Furthermore, the sintering temperature in S4 is 400℃~700℃, and the sintering time is 1~5 hours.
[0068] Furthermore, the acid solution in S5 is a hydrochloric acid solution with a concentration of 0.1~1.0 mol / L.
[0069] Example 1
[0070] The preparation of Ti-doped aluminum-based lithium adsorbent (AlTi-LAO) specifically includes: preparation of materials (solution A), including lithium chloride (LiCl) and aluminum trichloride hexahydrate. and titanium tetrachloride It dissolves in deionized water.
[0071] Among them, the molar ratio is controlled as follows: (That is, the doping amount is 1%).
[0072] Co-precipitation was performed, and a 2 mol / L NaOH solution was prepared as solution B. In a reaction vessel, solutions A and B were added in parallel under strong stirring at 60°C. The pH of the reaction system was maintained at 9.0 by controlling the flow rate of solution B. After the addition was completed, the reaction was continued for 1 hour to obtain a white suspension slurry.
[0073] The slurry was heated to 80°C and allowed to stand for 6 hours for aging. Then, the slurry was sent to a spray dryer for granulation and drying (inlet air temperature 200°C, outlet air temperature 100°C) to obtain spherical micro powder precursor.
[0074] Sintering: The spherical precursor was placed in a muffle furnace and sintered at 500℃ for 2 hours, followed by natural cooling. Activation: The sintered product was immersed in 0.5 mol / L HCl solution and stirred for 4 hours to remove lithium ions. It was then washed with deionized water until neutral and dried to obtain a Ti-doped aluminum-based lithium adsorbent, denoted as AlTi-LAO. Results: SEM images (Figure 2) show that the obtained AlTi-LAO consists of regular spherical particles with uniformly distributed nanoscale pores on the surface.
[0075] Example 2
[0076] This embodiment describes the preparation of a Zr-doped aluminum-based lithium adsorbent (AlZr-LAO). The aim of this example is to verify the doping effect of other elements (Zr) in Group IVB and to validate a wide range of process parameters. Specifically, the raw materials used include lithium nitrate, aluminum nitrate, and zirconium oxychloride. The molar ratio is controlled as follows: (Doping concentration increased to 2.5%). Co-precipitation was performed at a reaction temperature of 45°C, with the pH value maintained at 8.5 during the co-current feeding process. The slurry was aged at 70°C for 8 hours, followed by spray drying and granulation. Sintering was then carried out at a temperature of 600°C for 3 hours. Activation was performed following the same steps as in Example 1 to obtain a Zr-doped aluminum-based lithium adsorbent, denoted as AlZr-LAO.
[0077] Example 3
[0078] The preparation of Mn-doped aluminum-based lithium adsorbent (AlMn-LAO) was carried out in this embodiment to verify the doping effect of group VIIB element (Mn). The raw materials used were lithium chloride, aluminum chloride, and manganese chloride. The molar ratio is controlled at ), (Doping amount is 0.5%), co-precipitation, reaction temperature adjusted to 70℃, pH value controlled to be stable at 10.0 during co-current feeding, aging and granulation: the slurry is aged at 90℃ for 4 hours, and then spray dried and granulated, sintering: the sintering temperature is adjusted to 450℃, sintering time is 4 hours, activation: the steps are the same as in Example 1, and Mn-doped aluminum-based lithium adsorbent is obtained, denoted as AlMn-LAO.
[0079] Comparative Example 1
[0080] Preparation of Undoped Aluminum-Based Lithium Adsorbent (Al-LAO): To compare performance, an adsorbent without doping elements was prepared. Ingredients: Solution A contains only... No doped metal salts added, molar ratio Other steps: co-precipitation (pH=9.0, 60℃), aging, spray drying, sintering (500℃), and activation were all completely consistent with those in Example 1, and the resulting sample was denoted as Al-LAO;
[0081] Performance testing method description, lithium adsorption capacity test: Prepare simulated salt lake brine, in which... The concentration is 100 mg / L. The concentration is 2000 mg / L. (Mass ratio = 20), adjust the pH value to 7.0, take 0.1g of adsorbent sample and place it in 100mL of the above brine, and shake at a constant temperature of 25℃ for 24 hours.
[0082] After solid-liquid separation, the residual amount in the supernatant was determined using ICP-OES (inductively coupled plasma optical emission spectrometry). Concentration, calculate saturated adsorption capacity (mg / g).
[0083] Cyclic solubility test: The adsorbent was loaded into a dynamic adsorption column and subjected to an adsorption-washing-desorption (0.5 mol / L HCl)-washing cycle. After 10 cycles, all effluent was collected, the total amount of aluminum ions was measured, and the percentage relative to the initial aluminum content of the adsorbent was calculated and recorded as the aluminum solubility rate. Microscopic morphology characterization: The surface morphology and microstructure of the sample were observed using a scanning electron microscope (SEM).
[0084] The adsorbents prepared in the above embodiments were compared with the comparative sample in performance testing, and the results are shown in the table below:
[0085] In summary, the adsorption capacity of Examples 1-3 was significantly higher than that of Comparative Example 1. This indicates that the doping of elements such as Ti, Zr, and Mn did indeed cause lattice distortion or vacancies, effectively increasing the active adsorption sites for lithium ions. Among them, Ti doping showed the best effect.
[0086] Stability: After 10 adsorption-desorption cycles, the aluminum dissolution rate of the doped adsorbent (0.15%~0.21%) was significantly lower than that of the undoped sample (0.35%). This indicates that the doping element plays a "skeleton pinning" role, enhancing the stability of the crystal structure and making it more resistant to acid corrosion.
[0087] Applicability of parameters: Examples 2 and 3 demonstrate that high-performance adsorbents can be prepared within the range of pH 8.5-10.0 and sintering temperature 450-600℃, verifying the tolerance and universality of the process parameters of this invention.
[0088] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0089] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. An aluminum-based lithium adsorbent, characterized in that, The adsorbent is a spherical particle with a porous structure; the adsorbent is prepared by mixing and co-precipitating a lithium source, an aluminum source and a doped metal source in a liquid phase, followed by granulation, sintering and acid washing activation; Lix·Al(1-y)·My·(OH)3·nH2O; wherein, M is at least one metal element selected from Group IVB and Group VIIB; the value of x ranges from 0.5 to 1.2; the value of y ranges from 0.005 to 0.10; and n is the number of moles of water of crystallization.
2. The aluminum-based lithium adsorbent and its preparation method according to claim 1, characterized in that, The doped metal source is selected from at least one of titanium (Ti), zirconium (Zr), manganese (Mn) or tin (Sn).
3. The aluminum-based lithium adsorbent and its preparation method according to claim 1, characterized in that, The adsorbent has a lithium saturation adsorption capacity ≥6.0 mg / g; after 10 adsorption-desorption cycles, its aluminum dissolution rate is ≤0.20%.
4. A method for preparing a doped aluminum-based lithium adsorbent according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Ingredient preparation: Lithium source, aluminum source, and doped metal source M are dissolved in a solvent at a molar ratio to prepare a mixed salt solution (solution A); S2. Co-precipitation reaction: The mixed salt solution and alkaline solution (solution B) are added to the reactor in parallel flow. Under stirring conditions, the pH value and reaction temperature of the system are controlled to carry out a co-precipitation reaction to obtain a slurry; S3. Granulation and molding: The obtained slurry is aged and then dried and granulated by spray drying to obtain a microsphere precursor; S4. Sintering: The microsphere precursor is sintered and solidified at high temperature. S5. Activation: The sintered product is washed with an acid solution to displace lithium ions. After washing with water and drying, the doped aluminum-based lithium adsorbent is obtained.
5. The method for preparing an aluminum-based lithium adsorbent according to claim 1, characterized in that, In S1, the lithium source is lithium chloride, lithium nitrate, or lithium sulfate; the aluminum source is aluminum chloride, aluminum nitrate, or aluminum sulfate; the doped metal source M is a chloride, nitrate, or sulfate of the corresponding metal; in the mixed salt solution, the molar ratio of Li to (Al+M) is... 。 6. The method for preparing an aluminum-based lithium adsorbent according to claim 4, characterized in that, The pH value in S2 is controlled within the range of 8.0 to 10.5; the reaction temperature is controlled within the range of 40°C to 90°C; and the alkaline solution is an aqueous solution of sodium hydroxide, potassium hydroxide, or ammonia.
7. The method for preparing an aluminum-based lithium adsorbent according to claim 1, characterized in that, The aging temperature in S3 is 60℃~90℃, and the aging time is 4~12 hours.
8. The method for preparing an aluminum-based lithium adsorbent according to claim 1, characterized in that, The sintering temperature in S4 is 400℃~700℃, and the sintering time is 1~5 hours.
9. The method for preparing an aluminum-based lithium adsorbent according to claim 1, characterized in that, The acid solution in S5 is a hydrochloric acid solution with a concentration of 0.1~1.0 mol / L.