Aluminum-based lithium adsorbent particles, and a preparation method and application thereof

Abstract

The application discloses an aluminum lithium adsorbent particle and a preparation method and application thereof. The aluminum lithium adsorbent particle comprises an aluminum lithium adsorbent precursor powder, an organic solvent, a high polymer binder and an optional additive. The high polymer binder comprises a binder I and a binder II. The binder I is selected from one or more of polydopamine and derivatives thereof. The binder II is selected from a mixture of one or more of polysulfone, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose and chitosan. The application solves the problems of low proportion of the effective component, i.e. the aluminum lithium adsorbent precursor, large amount of the binder, low adsorption capacity after granulation and low lithium extraction efficiency in the existing molding and granulation technology.

Description

Technical Field

[0001] This invention relates to the field of lithium extraction technology, and in particular to an aluminum-based lithium adsorbent particle, its preparation method, and its application. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the demand for lithium is increasing. Lithium resources in nature are mainly found in salt lake brines and ores. Extracting lithium from ores is costly, while extracting lithium from salt lakes is simpler and cheaper. Therefore, extracting lithium from salt lakes has become the mainstream trend in the lithium industry.

[0003] The adsorption method for extracting lithium from salt lakes is a novel lithium extraction technology that has attracted widespread attention in recent years. The adsorption method utilizes the special adsorption properties of adsorbents for lithium ions. Through "adsorption" and "desorption," lithium ions are enriched among a variety of alkali metal ions, thus achieving selective lithium extraction. It is particularly suitable for lithium extraction from low-quality salt lakes with low lithium ion concentrations. The advantages of the adsorption method also lie in its environmental friendliness and suitability for large-scale use.

[0004] Aluminum-based lithium adsorbents are currently the only lithium adsorbents that have achieved industrial application. Their preparation process is simple, they are widely available, low in cost, and operate under mild conditions, requiring no special pH requirements for brine and eliminating the need for acid desorption. In recent years, they have attracted widespread attention from researchers both domestically and internationally. However, aluminum-based lithium adsorbents are often prepared as powders, which have small particle sizes and low strength. Direct application can lead to poor permeability, difficulty in solid-liquid separation, and high solubility. Therefore, they must be granulated into particles of a certain size before application. Researchers both domestically and internationally have been focusing on the granulation process of aluminum-based lithium adsorbents. However, regardless of the granulation method, especially industrially applied methods such as extrusion granulation, the proportion of the aluminum-based lithium adsorbent precursor generally does not exceed 80%. Otherwise, insufficient binder will prevent granulation, while excessive binder will lead to over-encapsulation of the aluminum-based lithium adsorbent precursor powder, rendering its lithium extraction active sites ineffective. Ultimately, this results in low adsorption capacity and low lithium extraction efficiency in the granulated aluminum-based lithium adsorbent. Therefore, developing a preparation process for high-capacity aluminum-based lithium adsorbent particles is crucial. Summary of the Invention

[0005] This invention aims to solve the problems of low proportion of effective component aluminum-based lithium adsorbent precursor, large amount of binder, low adsorption capacity after granulation, and low lithium extraction efficiency in existing molding and granulation technologies. It provides an aluminum-based lithium adsorbent particle, its preparation method, and its application.

[0006] To achieve the above-mentioned objective, the first aspect of the present invention provides aluminum-based lithium adsorbent particles, comprising aluminum-based lithium adsorbent precursor powder, organic solvent, polymeric binder, and optional additives. The polymeric binder comprises binder I and binder II. Binder I is selected from one or more of polydopamine and its derivatives, and binder II is selected from one or a mixture of several of polysulfone, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose, and chitosan.

[0007] Furthermore, the mass ratio of the aluminum-based lithium adsorbent precursor powder to the polymer binder is 4–99:1, preferably 9–19:1.

[0008] Furthermore, the mass ratio of adhesive I to adhesive II is 1:4 to 2:1.

[0009] Furthermore, the adhesive I and adhesive II are mixed at a temperature of 50–90°C to obtain a polymer adhesive, and the mixing time is 0.5–5 h.

[0010] Furthermore, the polydopamine derivatives include, but are not limited to, acetyldopamine polymers and polydopamine-modified polysulfones, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose, chitosan, or, but not limited to, metal ion-doped polydopamine materials.

[0011] Further, the organic solvent is one or a mixture of several of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, chloroform, dichloroethane, and ethyl acetate. Preferably, the amount of organic solvent used is 60 to 100% of the total weight of the polymer binder and the precursor powder.

[0012] Further, the additive is one or a mixture of several of the following: polyvinyl alcohol, PVP K30, PVP K60, PVP K90, PEG-200, PEG-400, PEG-1000, PEG-2000, PEG-6000, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, Tween 80, Span 40, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, and bis-(3-(triethoxysilane)-propyl)-tetrasulfide; preferably, the amount of additive is 0.1-5 wt% of the precursor powder mass.

[0013] A second aspect of this invention provides a method for preparing aluminum-based lithium adsorbent particles, comprising the following steps:

[0014] 1) Mix organic solvent, polymer binder, aluminum-based lithium adsorbent precursor powder and optional additives at high temperature until homogeneous to obtain a mixture;

[0015] 2) The mixture is dried, pulverized, and sieved to obtain a semi-finished aluminum-based lithium adsorbent;

[0016] 3) Activate the semi-finished aluminum-based lithium adsorbent with deionized water to obtain granular aluminum-based lithium adsorbent.

[0017] Furthermore, the preparation method of the aluminum-based lithium adsorbent precursor powder includes: reacting an aluminum source and a lithium source in water to obtain a mixed solution, adjusting the pH of the mixed solution to 4-10 using an alkaline solution, then aging and separating to obtain a solid, and washing, drying and pulverizing the solid to obtain a lithium-intercalated aluminum-based lithium adsorbent precursor powder.

[0018] Further, the aluminum source is one or a mixture of several of aluminum chloride, aluminum oxide, aluminum hydroxide, aluminum sulfate, and polyaluminum chloride; the lithium source is one or a mixture of several of lithium chloride, lithium hydroxide, lithium sulfate, lithium carbonate, and lithium nitrate; the alkaline solution is one or a mixture of several of sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonia water, preferably, the concentration of the alkaline solution is 0.5 to 5 mol / L.

[0019] Furthermore, the curing temperature is 50–110°C, and the curing time is 0.5–2 hours.

[0020] Furthermore, the precursor powder after pulverization and sieving has a particle size of 0.5–100 μm, preferably 1–10 μm.

[0021] Further, the step of reacting the aluminum source and lithium source in water to obtain a mixed solution includes: simultaneously adding the aluminum source and lithium source to water at a certain rate in a certain proportion, stirring and dissolving them evenly at high temperature, and then reacting; preferably, the amount of aluminum source and lithium source added is based on an aluminum-lithium molar ratio of 1.2 to 6:1, the dropping rate is 2 to 6 mL / min, the amount of water added ensures that the total solid content of the mixed solution is 40 to 60 wt%, the reaction time is 1 to 8 h, and the reaction temperature is 50 to 110 °C.

[0022] Furthermore, in step 2), the particle size of the aluminum-based lithium adsorbent semi-finished product obtained by crushing and sieving is 0.3 mm to 3.0 mm.

[0023] Furthermore, in step 3), the activation temperature is 40–80°C and the activation time is 1–15 h.

[0024] A third aspect of the present invention provides aluminum-based lithium adsorbent particles prepared by the above method.

[0025] The fourth aspect of this invention provides the application of the above-mentioned aluminum-based lithium adsorbent particles for lithium extraction from low-quality salt lakes with low lithium ion concentration, high magnesium-to-lithium ratio, and high sodium-to-lithium ratio.

[0026] In this article, the precursor powder is the aluminum-based lithium adsorbent precursor powder.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] The aluminum-based lithium adsorbent particles provided by the present invention include aluminum-based lithium adsorbent precursor powder, organic solvent, polymer binder, and optional additives. The polymer binder includes a special binder I and a common binder II. The binder I is selected from one or more of polydopamine and its derivatives, and the binder II is selected from one or a mixture of several of polysulfone, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose, and chitosan. This invention utilizes a specific combination of binder I and binder II, which reduces the amount of binder used and increases the proportion of aluminum-based lithium adsorbent precursor powder. This significantly increases the effective component ratio of the shaped aluminum-based lithium adsorbent particles. Furthermore, the special binder used in this invention imparts a certain degree of hydrophilicity to the aluminum-based lithium adsorbent particles, enhancing the interaction between the adsorbent and brine and improving the lithium extraction rate. Additionally, the presence of amino and hydroxyl groups with secondary reactive properties in polydopamine exhibits unique adhesiveness, resulting in a stronger bond between the aluminum-based lithium adsorbent precursor powder and improved wear resistance and cycle life. Therefore, the aluminum-based lithium adsorbent particles of this invention possess ultra-high adsorption capacity, high porosity, and high lithium extraction rate, along with advantages such as low wear rate and high cycle life. Moreover, the preparation process of this invention is simple, the entire granulation process is straightforward and controllable, and it is easy to industrialize. The aluminum-based lithium adsorbent particles of this invention can be used for lithium extraction from low-quality salt lakes with low lithium-ion concentrations, high magnesium-to-lithium ratios, and high sodium-to-lithium ratios, showing broad prospects for industrial application.

[0029] Other features and advantages of the present invention will be described in detail through the following specific embodiments. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the morphology of the adsorbent sample in Example 1 of the present invention.

[0031] Figure 2 This is a schematic SEM image of the adsorbent sample surface in Example 1 of the present invention.

[0032] Figure 3 This is a schematic SEM image of the cross-section of the adsorbent sample in Example 1 of the present invention. Detailed Implementation

[0033] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0034] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0035] Unless otherwise specified, all raw materials involved in this invention are available from commercially available sources.

[0036] The first aspect of the present invention provides aluminum-based lithium adsorbent particles, comprising aluminum-based lithium adsorbent precursor powder, organic solvent, polymeric binder, and optional additives, wherein the polymeric binder comprises binder I and binder II, wherein binder I is selected from one or more of polydopamine and its derivatives, and binder II is selected from one or a mixture of several of polysulfone, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose, and chitosan.

[0037] In a preferred embodiment of this application, the mass ratio of the aluminum-based lithium adsorbent precursor powder to the polymer binder is 4 to 99:1, preferably 9 to 19:1, to avoid insufficient binder for molding.

[0038] As a preferred embodiment of this application, the mass ratio of binder I to binder II is 1:4 to 2:1, exemplarily 1:4, 1:3, 1:2, 1:1, 1.5:1, or 2:1, to prevent excessive addition of special binder I, which would result in insufficient strength of the adsorbent particles after molding.

[0039] In a preferred embodiment of this application, adhesive I and adhesive II are mixed at a temperature of 50–90°C to obtain a polymeric adhesive, and the mixing time is 0.5–5 h.

[0040] In a preferred embodiment of this application, the polydopamine derivatives include, but are not limited to, acetyldopamine polymers and polydopamine-modified polysulfones, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose, chitosan, etc., and also include doped polydopamine materials, such as Al 3+ Fe 3+ Materials such as polydopamine doped with metal ions.

[0041] As a preferred embodiment of this application, the organic solvent is one or a mixture of several of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, chloroform, dichloroethane, and ethyl acetate. Preferably, the amount of organic solvent used is 60-100% of the total weight of the polymer binder and the precursor powder.

[0042] In a preferred embodiment of this application, the additive is one or a mixture of several of the following: polyvinyl alcohol, PVP K30, PVPK60, PVP K90, PEG-200, PEG-400, PEG-1000, PEG-2000, PEG-6000, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, Tween 80, Span 40, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, and bis-(3-(triethoxysilane)-propyl)-tetrasulfide; preferably, the amount of additive is 0.1-5 wt% of the precursor powder mass.

[0043] A second aspect of this invention provides a method for preparing aluminum-based lithium adsorbent particles, comprising the following steps:

[0044] 1) Mix organic solvent, polymer binder, aluminum-based lithium adsorbent precursor powder and optional additives at high temperature until homogeneous to obtain a mixture;

[0045] 2) The mixture is dried, pulverized, and sieved to obtain a semi-finished aluminum-based lithium adsorbent;

[0046] 3) Activate the semi-finished aluminum-based lithium adsorbent with deionized water to obtain granular aluminum-based lithium adsorbent.

[0047] As a preferred embodiment of this application, the preparation method of the aluminum-based lithium adsorbent precursor powder includes: reacting an aluminum source and a lithium source in water to obtain a mixed solution, adjusting the pH of the mixed solution to 4-10 using an alkaline solution, then aging and separating to obtain a solid, and washing, drying and pulverizing the solid to obtain a lithium-intercalated aluminum-based lithium adsorbent precursor powder.

[0048] In a preferred embodiment of this application, the aluminum source is one or a mixture of several of aluminum chloride, aluminum oxide, aluminum hydroxide, aluminum sulfate, and polyaluminum chloride; the lithium source is one or a mixture of several of lithium chloride, lithium hydroxide, lithium sulfate, lithium carbonate, and lithium nitrate; and the alkaline solution is one or a mixture of several of sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonia water. Preferably, the concentration of the alkaline solution is 0.5–5 mol / L.

[0049] As a preferred embodiment of this application, the step of reacting the aluminum source and lithium source in water to obtain a mixed solution includes: simultaneously adding the aluminum source and lithium source to water at a certain rate in a certain proportion, stirring and dissolving them evenly at high temperature, and then reacting; preferably, the amount of aluminum source and lithium source added is based on an aluminum-lithium molar ratio of 1.2 to 6:1, the dropping rate is 2 to 6 mL / min, the amount of water added ensures that the total solid content of the mixed solution is 40 to 60 wt%, the reaction time is 1 to 8 h, and the reaction temperature is 50 to 110 °C.

[0050] In a preferred embodiment of this application, the curing temperature is 50–110°C and the curing time is 0.5–2 hours.

[0051] In a preferred embodiment of this application, the precursor powder after pulverization and sieving has a particle size of 0.5–100 μm, preferably 1–10 μm, in order to expose the lithium extraction active sites of the adsorbent after granulation more fully. An air jet mill can be selected as the pulverizing equipment.

[0052] In a preferred embodiment of this application, in step 2), the particle size of the aluminum-based lithium adsorbent semi-finished product obtained by crushing and sieving is 0.3 mm to 3.0 mm.

[0053] As a preferred embodiment of this application, in step 2), the drying method is one or a combination of several of the following: atmospheric pressure drying, reduced pressure drying, boiling drying, and freeze drying, until the residual amount of organic solvent is 0-5%.

[0054] In a preferred embodiment of this application, in step 3), the activation temperature is 40-80°C and the activation time is 1-15 hours. The purpose of activation is to obtain granular aluminum-based lithium adsorbent after delithiation of the aluminum-based lithium adsorbent semi-finished product by hot water.

[0055] A third aspect of the present invention provides aluminum-based lithium adsorbent particles prepared by the above method.

[0056] The fourth aspect of this invention provides the application of the above-mentioned aluminum-based lithium adsorbent particles for lithium extraction from low-quality salt lakes with low lithium ion concentration, high magnesium-to-lithium ratio, and high sodium-to-lithium ratio.

[0057] The present invention will be further described below with reference to the embodiments:

[0058] Example 1

[0059] 200g AlCl3 was dissolved in 300g deionized water, and 50g lithium hydroxide was dissolved in 300g deionized water. The solutions were then added dropwise to a three-necked flask at a rate of 3mL / min. The mixture was stirred and dissolved evenly at 70℃ for 6 hours. Then, 3mol / L NaOH aqueous solution was added dropwise to the mixed solution until the pH was 5. The mixture was then aged at 50℃ for 1 hour and filtered. The filtrate was washed twice, dried in an oven, and ground to obtain a lithium-based aluminum adsorbent precursor powder with a particle size of 5μm.

[0060] Weigh 900g of the above aluminum-based lithium adsorbent precursor powder, 20g of polydopamine, 80g of polyvinylidene fluoride, 1000g of N,N-dimethylacetamide, and 10g of PVP K60. Mix them in a kneader at 80°C for 2 hours to obtain a mixture. Then, use an atmospheric pressure drying oven to remove the solvent.

[0061] The above mixture is crushed, and particles with a diameter of 0.5-2 mm are sieved out. The mixture is then activated with deionized water at 50°C for 1 hour to obtain granular aluminum-based lithium adsorbent.

[0062] Example 2

[0063] The preparation of the lithium-intercalated aluminum-based lithium adsorbent precursor powder is the same as in Example 1;

[0064] Weigh 920g of the above aluminum-based lithium adsorbent precursor powder, 30g of polydopamine, 50g of polyvinylidene fluoride, 900g of N,N-dimethylacetamide, and 10g of PVP K60. Mix them in a kneader at 80°C for 2 hours to obtain a mixture. Then use an atmospheric pressure drying oven to remove the solvent.

[0065] The above mixture is crushed, and particles with a diameter of 0.5-2 mm are sieved out. The mixture is then activated with deionized water at 50°C for 1 hour to obtain granular aluminum-based lithium adsorbent.

[0066] Example 3

[0067] 100g Al(OH)3 was dissolved in 200g deionized water, and 40g lithium chloride was dissolved in 100g deionized water. The solutions were then added dropwise to a three-necked flask at a rate of 5mL / min. The mixture was stirred and dissolved evenly at 110℃ for 3h. Then, 3mol / L NaOH aqueous solution was added dropwise to the mixed solution until the pH was 7. The mixture was then aged at 60℃ for 0.5h and filtered. The filtrate was washed twice, dried in an oven, and ground to obtain an aluminum-based lithium adsorbent precursor powder with a particle size of 3μm.

[0068] Weigh 850g of the above-mentioned aluminum-based lithium adsorbent precursor powder, 50g of acetyl dopamine polymer, 100g of polyvinyl chloride, 900g of N-methylpyrrolidone, 5g of PEG-200, 0.5g of Tween 80, and 5g of vinyltrimethoxysilane. Mix them in a kneader at 70°C for 1 hour to obtain a mixture. Then, use an atmospheric pressure drying oven to remove the solvent.

[0069] The above mixture is crushed, and particles with a diameter of 0.5-2 mm are sieved out. The mixture is then activated with deionized water at 50°C for 1 hour to obtain granular aluminum-based lithium adsorbent.

[0070] Example 4

[0071] 150g Al(OH)3 was dissolved in 300g deionized water, and 100g lithium nitrate was dissolved in 300g deionized water. Then, both were added dropwise to a three-necked flask at a rate of 3mL / min. After stirring and dissolving evenly at 190℃, the mixture was reacted for 5h. Then, 3mol / L sodium carbonate aqueous solution was added dropwise to the mixed solution until the pH=4. After aging at 70℃ for 1h, the mixture was filtered. The filtrate was washed twice, dried in an oven, and ground to obtain an aluminum-based lithium adsorbent precursor powder with a particle size of 3μm.

[0072] Weigh 950g of the above-mentioned aluminum-based lithium adsorbent precursor powder, 20g of polydopamine, 30g of polyvinylidene fluoride, 1000g of N-methylpyrrolidone, 5g of PEG-200, 0.5g of Tween 80, and 5g of vinyltrimethoxysilane. Mix them in a kneader at 70°C for 1 hour to obtain a mixture. Then, use an atmospheric pressure drying oven to remove the solvent.

[0073] The above mixture is crushed, and particles with a diameter of 0.5-2 mm are sieved out. The mixture is then activated with deionized water at 50°C for 1 hour to obtain granular aluminum-based lithium adsorbent.

[0074] Example 5

[0075] The preparation of the lithium-intercalated aluminum-based lithium adsorbent precursor powder is the same as in Example 2;

[0076] Weigh 980g of the above-mentioned aluminum-based lithium adsorbent precursor powder, 14g of polydopamine, 7g of polyvinyl chloride, 900g of N-methylpyrrolidone, 5g of PEG-200, 0.5g of Tween 80, and 5g of vinyltrimethoxysilane. Mix them in a kneader at 70°C for 1 hour to obtain a mixture. Then, use an atmospheric pressure drying oven to remove the solvent.

[0077] The above mixture is crushed, and particles with a diameter of 0.5-2 mm are sieved out. The mixture is then activated with deionized water at 50°C for 1 hour to obtain granular aluminum-based lithium adsorbent.

[0078] Comparative Example 1

[0079] 2000g of lithium aluminum intercalation adsorbent precursor powder with a particle size of 5μm prepared in Example 1 was mixed evenly with 1000g of polyvinylidene fluoride and 3000g of chloroform, and then extruded and granulated using a screw extruder. The pelletizer cut the pellets into 1-1.5mm columnar particles.

[0080] The above particles were activated with deionized water at 50°C for 1 hour to obtain columnar aluminum-based lithium adsorbent.

[0081] Comparative Example 2

[0082] The preparation of the lithium-intercalated aluminum-based lithium adsorbent precursor powder is the same as in Example 1;

[0083] Weigh 900g of the above-mentioned aluminum-based lithium adsorbent precursor powder, 0g of polydopamine, 100g of polyvinylidene fluoride, 900g of N,N-dimethylacetamide, and 10g of PVP K60, and mix them in a kneader at 80°C for 2 hours to obtain a mixture.

[0084] The above mixture cannot be formed into a single unit, and a significant amount of aluminum-based lithium adsorbent precursor powder remains unable to bond together.

[0085] Adsorption capacity detection method:

[0086] Approximately 50g (dry weight) of adsorbent particles were loaded into glass chromatography columns. Adsorption was performed using brine 1 (high magnesium-to-lithium ratio) and brine 2 (high sodium-to-lithium ratio) from two different salt lakes, with an adsorption time of 1 hour each. The adsorption was then eluented with deionized water at room temperature for 1 hour. The adsorption capacity and eluent capacity were calculated based on the lithium ion concentration difference in the water samples. The test results are as follows:

[0087]

[0088] (mg / g) (mg / g) (mg / g) (mg / g) Example 1 13.5 13.5 18.4 18.4 Example 2 13.8 13.8 18.7 18.8 Example 3 11.8 11.8 14.7 14.7 Example 4 15.3 15.3 20.2 20.1 Example 5 14.3 14.3 19.2 1.1 Comparative Example 1 11.2 11.2 14.3 14.3 Comparative Example 2 8.8 7.9 11.8 11.8

[0089] As can be seen from the table above, the addition of polydopamine can increase the proportion of aluminum-based lithium adsorbent precursor components to 98%, and obtain adsorption and desorption capacities that are significantly higher than those of conventional extrusion granulation. Moreover, the higher the proportion of aluminum-based lithium adsorbent precursor, the greater the proportion of polydopamine in the binder.

[0090] Cycle life evaluation method:

[0091] Following the adsorption and desorption processes in the adsorption capacity detection method, using the sample from Example 4, a certain salt lake brine 1, simulating 1000 cycles of continuous dynamic operation in an industrial setting, the dissolution loss was calculated based on the mass difference of the adsorbent. The specific test results are as follows:

[0092]

[0093] As can be seen from the table above, the prepared granular aluminum-based lithium adsorbent has good cycle stability, long lifespan, and low dissolution loss.

[0094] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are within the spirit and scope of the present invention.

Claims

1. An aluminum-based lithium adsorbent particle, characterized in that, The product comprises aluminum-based lithium adsorbent precursor powder, organic solvent, polymeric binder, and optional additives. The polymeric binder includes binder I and binder II. Binder I is selected from one or more of polydopamine and its derivatives, and binder II is selected from one or a mixture of several of polysulfone, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose, and chitosan. The mass ratio of the aluminum-based lithium adsorbent precursor powder to the polymeric binder is 9~99:1, and the mass ratio of binder I to binder II is 1:4~2:

1.

2. The aluminum-based lithium adsorbent particles according to claim 1, characterized in that, The mass ratio of the aluminum-based lithium adsorbent precursor powder to the polymer binder is 9~19:

1.

3. The aluminum-based lithium adsorbent particles according to claim 1 or 2, characterized in that, The adhesive I and adhesive II are mixed at a temperature of 50~90℃ to obtain a polymer adhesive, and the mixing time is 0.5~5h.

4. The aluminum-based lithium adsorbent particles according to claim 1, characterized in that, The polydopamine derivatives include, but are not limited to, acetyldopamine polymers and polydopamine-modified polysulfones, polyvinylidene fluoride, polyvinyl chloride, chlorinated polyvinyl chloride, cellulose acetate, carboxymethyl cellulose, chitosan, or polydopamine materials including, but not limited to, metal ion-doped polydopamine materials. The organic solvent is one or a mixture of several of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, chloroform, dichloroethane, and ethyl acetate; and / or, The additive is one or a mixture of several of the following: polyvinyl alcohol, PVP K30, PVP K60, PVP K90, PEG-200, PEG-400, PEG-1000, PEG-2000, PEG-6000, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, Tween 80, Span 40, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, and bis-(3-(triethoxysilane)-propyl)-tetrasulfide.

5. The aluminum-based lithium adsorbent particles according to claim 4, characterized in that, The amount of organic solvent used is 60-100% of the total weight of polymer binder and precursor powder; the amount of additive used is 0.1-5 wt% of the precursor powder.

6. A method for preparing aluminum-based lithium adsorbent particles according to any one of claims 1-5, characterized in that, Includes the following steps: 1) Mix organic solvent, polymer binder, aluminum-based lithium adsorbent precursor powder and optional additives at high temperature until homogeneous to obtain a mixture; 2) The mixture is dried, pulverized, and sieved to obtain a semi-finished aluminum-based lithium adsorbent; 3) Activate the semi-finished aluminum-based lithium adsorbent with deionized water to obtain granular aluminum-based lithium adsorbent.

7. The method for preparing aluminum-based lithium adsorbent particles according to claim 6, characterized in that, The preparation method of the aluminum-based lithium adsorbent precursor powder includes: reacting an aluminum source and a lithium source in water to obtain a mixed solution, adjusting the pH of the mixed solution to 4-10 with an alkaline solution, then aging and separating to obtain a solid, washing, drying and pulverizing the solid to obtain a lithium-intercalated aluminum-based lithium adsorbent precursor powder.

8. The method for preparing aluminum-based lithium adsorbent particles according to claim 7, characterized in that, The aluminum source is one or a mixture of several selected from aluminum chloride, aluminum oxide, aluminum hydroxide, aluminum sulfate, and polyaluminum chloride; the lithium source is one or a mixture of several selected from lithium chloride, lithium hydroxide, lithium sulfate, lithium carbonate, and lithium nitrate; the alkaline solution is one or a mixture of several selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonia water; and / or, The curing temperature is 50~110℃, and the curing time is 0.5~2h; and / or, The precursor powder after pulverization and sieving has a particle size of 0.5~100μm; And / or, The process of reacting aluminum and lithium sources in water to obtain a mixed solution includes: simultaneously adding aluminum and lithium sources to water at a certain rate in a certain proportion, stirring and dissolving them evenly at high temperature, and then reacting.

9. The method for preparing aluminum-based lithium adsorbent particles according to claim 8, characterized in that, The concentration of the alkali solution is 0.5~5 mol / L, and the particle size of the precursor powder after pulverization and sieving is 1~10 μm; The amount of aluminum source and lithium source added is based on an aluminum-lithium molar ratio of 1.2 to 6:1, the dropping rate is 2 to 6 mL / min, the amount of water added ensures that the total solid content of the mixed solution is 40 to 60 wt%, the reaction time is 1 to 8 h, and the reaction temperature is 50 to 110 °C.

10. The method for preparing aluminum-based lithium adsorbent particles according to claim 6, characterized in that, In step 2), the particle size of the aluminum-based lithium adsorbent semi-finished product obtained by crushing and sieving is 0.3 mm to 3.0 mm; and / or, In step 3), the activation temperature is 40~80℃ and the activation time is 1~15h.

11. Aluminum-based lithium adsorbent particles prepared by the method according to any one of claims 6-10.

12. The application of the aluminum-based lithium adsorbent particles according to any one of claims 1-5 or the aluminum-based lithium adsorbent particles prepared by the method according to any one of claims 6-10, characterized in that, It was used for lithium extraction from low-quality salt lakes.

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