Preparation and application of crown ether-loaded solid bubble lithium adsorbent

Abstract

The invention relates to a crown ether-loaded solid bubble lithium adsorbent as well as a preparation method and application thereof, belongs to the technical field of lithium adsorption, and solves the problems of low adsorption rate, low adsorption capacity, poor ion selective adsorbability, complex synthesis process, difficulty in separation and recovery, poor regeneration capacity and water environment pollution during lithium extraction of an existing crown ether material. The method comprises the following steps: activating solid bubbles by adopting an alkaline solution; modifying the activated solid bubbles by using a coupling agent; and reacting a crown ether monomer with a lithium salt in a solvent, adding the modified solid bubbles, a catalyst, a cross-linking agent and an initiator, continuously reacting, carrying out solid-liquid separation, washing, drying and eluting. The method is simple and environment-friendly, the stably immobilized crown ether is introduced to the surface of the solid bubble through chemical grafting, and the lithium adsorption performance of the crown ether is improved; the solid bubbles with low density and high stability can endow the adsorbent with the self-floating characteristic, the regeneration performance of crown ether is remarkably improved, and pollution to the water environment is reduced.

Description

Technical Field

[0001] This invention relates to the field of lithium adsorption technology, and in particular to a solid bubble lithium adsorbent supported on crown ether, its preparation method, and its application. Background Technology

[0002] Lithium is an essential element in modern life, and its derivatives and various compounds have wide applications in industry. By 2050, global lithium production will need to increase by approximately 500% to meet projected energy storage demand. This surge necessitates the development of more efficient lithium extraction methods to meet the growing demand for clean energy technologies.

[0003] Lithium exists primarily in various natural forms, such as lithium-bearing pegmatite deposits, brine reservoirs in salt lakes, and sedimentary deposits associated with clay minerals. Currently, lithium is mainly extracted from brines, pegmatites, or sedimentary rocks in South America and China, exhibiting limited availability. This necessitates the development of alternative methods for lithium extraction and recovery. Salt lake brines contain abundant lithium resources, and lithium extraction from them can effectively reduce the environmental problems associated with mining. Extraction of lithium from salt lake brines is both economically and technically feasible. This characteristic places salt lake brines at the forefront of lithium extraction research and development, highlighting their strategic importance in the industry. Currently, the main methods for extracting lithium from brine include solar evaporation, direct lithium extraction (DLE), membrane technology, geothermal extraction, and electrochemical methods. In particular, the adsorption method of DLE, renowned for its simplicity, economy, and high selectivity, has become a focal point, possessing significant economic and strategic value.

[0004] Crown ethers are cyclic compounds constructed from bonded ethers, possessing various cavity sizes. They can coordinate with lithium ions through dipole-charge electrostatic interactions to form stable complexes, thereby achieving selective adsorption of lithium ions in brine. Furthermore, crown ethers also exhibit good performance in lithium isotope separation. However, the lithium adsorption rate of crown ether composite materials is relatively slow, making it difficult to rapidly separate and recover powdered materials from the liquid phase during lithium extraction, posing a certain degree of harm to the aquatic environment. Currently, crown ethers are often used as ligands immobilized on various porous matrices to design and synthesize crown ether-supported adsorbents to address this issue. However, the synthesis process of immobilizing crown ether ligands on various porous matrices is complex, and the long-range diffusion path further prolongs the time for lithium ions to reach the crown ether adsorption sites, resulting in high mass transfer resistance and a slow overall adsorption kinetics. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a solid bubble lithium adsorbent supported on crown ethers, its preparation method and application, to solve at least one of the problems in the prior art of low adsorption rate, low adsorption capacity, poor ion selectivity, complex synthesis process, difficulty in separation and recovery, poor regeneration capacity, and pollution of aquatic environment when extracting lithium from crown ether materials.

[0006] On one hand, embodiments of the present invention provide a method for preparing a solid bubble lithium adsorbent supported on crown ethers, the method comprising: S1: Solid bubbles are activated using an alkaline solution; S2: Modify the solid bubbles activated in step (1) with a coupling agent to obtain modified solid bubbles; S3: The crown ether monomer and lithium salt are reacted in a solvent, the modified solid bubbles, catalyst, crosslinking agent and initiator are added, the reaction is continued, solid-liquid separation is performed, and the mixture is washed, dried and eluted to obtain the solid bubble lithium adsorbent.

[0007] Furthermore, in step S1, the solid bubble is one or more of hollow glass microspheres, insulated glass microspheres, fly ash cenospheres, and ceramic bubbles; Furthermore, the density of the solid bubbles is 0.10~0.90 g / cm³. 3 The particle size is 10-1000 μm, and the compressive strength is between 1 MPa and 200 MPa.

[0008] Furthermore, in step S1, the alkaline solution is an aqueous solution of sodium hydroxide or potassium hydroxide with a concentration of 0.5-5 mol / L.

[0009] Furthermore, in step S1, the activation treatment is performed at a temperature of 40-80°C for 1-4 hours.

[0010] Furthermore, in step S2, the coupling agent is a silane coupling agent, and the mass ratio of the activated solid bubble to the silane coupling agent is 1:0.5~4.

[0011] Furthermore, in step S2, the modification temperature is 50~80℃ and the time is 1~4 h.

[0012] Furthermore, in step S3, the crown ether monomer is at least one of 2-hydroxymethyl-12-crown ether-4, 4-formylbenzo-15-crown ether-5, and dibenzo-14-crown ether-4, and the molar ratio of the crown ether monomer to the lithium salt is 1:1-1.5.

[0013] Furthermore, in step S3, the mass ratio of the crown ether to the modified solid bubble is 1:1-2.5; Furthermore, the temperature for the continued reaction is 50-180℃, and the time is 12-24h.

[0014] Secondly, embodiments of the present invention provide a solid bubble lithium adsorbent supported on crown ether, wherein the solid bubble lithium adsorbent is prepared by the above method.

[0015] Thirdly, embodiments of the present invention provide a method for applying a crown ether-loaded solid bubble lithium adsorbent to adsorb and extract lithium from salt lake brine, wherein the solid bubble lithium adsorbent is a solid bubble lithium adsorbent prepared by the above method or the above-mentioned solid bubble lithium adsorbent.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. Compared with existing crown ether adsorbents for lithium extraction, this invention chemically grafts crown ethers onto the surface of solid bubbles with a large specific surface area. This improves the dispersibility of the lithium adsorbent and enhances its adsorption and extraction capacity for lithium. Furthermore, the density of the solid bubbles (0.1-0.9 g / cm³) is reduced. 3 The density is lower than that of water, allowing it to float during lithium extraction, thus achieving efficient solid-liquid separation, reducing the difficulty of adsorbent recovery, and minimizing water pollution. The high mechanical strength and stable material give the adsorbent excellent cycle stability, which is beneficial for long-term recycling in industrial applications. The preparation method of this invention is simple, environmentally friendly, and conducive to large-scale industrial production.

[0017] 2. This invention regulates the particle size of solid bubbles, enabling the low-density composite lithium adsorbent to have good dispersibility during use and preventing agglomeration while providing the largest possible specific surface area to achieve more lithium adsorbent coating.

[0018] 3. This invention regulates the concentration of the strong alkaline solution and its ratio with the solid bubbles to be etched, which not only achieves surface degreasing but also enables further surface etching, improves interface roughness, increases the number of sites for the lithium adsorbent obtained in subsequent reactions on the solid bubbles, and enriches the surface of the etched solid bubbles with hydroxyl groups. Combined with the subsequent modification treatment of the coupling agent, this promotes the grafting of the lithium adsorbent obtained after the reaction onto the solid bubbles and improves the stability of the lithium adsorbent loading.

[0019] 4. This invention regulates the ratio of solid bubbles to crown ether, thereby controlling the mass ratio of solid bubbles to lithium adsorbent in the composite lithium adsorbent and maintaining the density of the solid bubble adsorbent at less than 1 g / cm³. 3 Within a certain range, the adsorbent can float during the lithium extraction process, thereby achieving efficient solid-liquid separation and reducing the difficulty of recovery.

[0020] 5. The solid bubble lithium adsorbent of the present invention can float on the surface of the liquid phase during the extraction of lithium. The initial lithium adsorption capacity is ≥6 mg / g. After 10 cycles of adsorption, the overall recoverability of the material is not less than 96%, and its adsorption capacity retention rate can still be maintained at more than 90% compared with the initial adsorption, showing excellent recyclability, cycle stability and practical value.

[0021] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0022] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Figure 1 The curves showing the change of lithium adsorption capacity of the products obtained in Example 1, Comparative Example 2, and Comparative Example 3 as a function of adsorption time are shown. Figure 2 This is a graph showing the adsorption capacity of the product obtained in Example 1 for lithium and other metal ions. Figure 3 The diagram shows the results of the regeneration and cyclic adsorption experiments of the products prepared in Example 1 and Comparative Example 3. Detailed Implementation

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0024] Although crown ethers can form stable complexes with lithium ions through dipole-charge electrostatic interactions to achieve selective adsorption of lithium ions in brine, the lithium adsorption rate of crown ether composite materials is relatively slow. When used for lithium extraction, the powder material is difficult to separate and recover quickly from the liquid phase, posing a certain degree of harm to the aquatic environment. Therefore, crown ethers are currently used as ligands immobilized on various porous matrices to design and synthesize crown ether-supported adsorbents to address this problem. However, the synthesis process of immobilizing crown ether ligands on various porous matrices is complex, and the long-range diffusion path further prolongs the time for lithium ions to reach the crown ether adsorption site, resulting in high mass transfer resistance and a slow overall adsorption kinetic.

[0025] The inventors discovered that flotation separation technology, which uses low-density properties to make substances float on the water surface for easy solid-liquid separation, has the characteristics of fast separation rate and low energy consumption. It can be applied to solve the problems of difficult separation and recovery and water pollution when extracting lithium from salt lake brine using crown ether materials. The inventors innovatively combined flotation separation technology with crown ether to prepare a new composite lithium adsorbent material with specific selectivity and easy recycling, so as to promote the efficient development and utilization of lithium resources.

[0026] In a preferred embodiment of the present invention, the present invention provides a method for preparing a solid bubble lithium adsorbent supported on crown ethers, the method comprising: S1: Solid bubbles are activated using an alkaline solution; S2: Modify the solid bubbles activated in step (1) with a coupling agent to obtain modified solid bubbles; S3: The crown ether and lithium salt are reacted in a solvent, the modified solid bubbles, catalyst, crosslinking agent and initiator are added, the reaction is continued, solid-liquid separation is performed, and the mixture is washed, dried and eluted to obtain the solid bubble lithium adsorbent.

[0027] Compared with existing technologies, the preparation method of the solid bubble lithium adsorbent of this invention solves the problems of low lithium adsorption rate, low capacity, complex synthesis process, and difficulty in separation and recovery of existing crown ether adsorbent materials. This invention uses low-density solid bubbles as a matrix and introduces crown ether monomers containing epoxy groups on its surface through chemical grafting, thereby forming a stable crown ether-supported solid bubble lithium adsorbent. The low density gives the adsorbent self-floating properties, which is beneficial for solid-liquid separation. The stabilized loading can reduce the pollution of the aquatic environment by crown ether. Combined with the good mechanical strength of solid bubbles, it is conducive to the recycling of adsorbent and reduces energy consumption and cost. In addition, the spherical structure of solid bubbles can effectively improve the dispersibility of adsorbent in brine, reduce mass transfer resistance, and improve adsorption kinetics.

[0028] The composite lithium adsorbent prepared by the method of this invention has good adsorption performance. Based on the specific recognition function of crown ether for lithium ions and the synergistic adsorption design, the prepared product has high selective lithium adsorption performance and can selectively adsorb lithium ions from complex solutions containing a variety of associated ions.

[0029] Specifically, in S1, the solid bubble is a type of material consisting of a solid shell surrounding a large number of closed gas cavities inside, and can be at least one of hollow glass microspheres, insulated glass microspheres, fly ash cenospheres, and ceramic bubbles.

[0030] Specifically, the density of the solid bubbles is 0.10-0.90 g / cm³. 3By controlling the density of solid bubbles to a small size, the prepared composite lithium adsorbent can be made to float during the extraction of lithium from salt lake brine.

[0031] Specifically, the particle size of the solid bubbles is 10-1000 μm, and can be 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 850 μm, 900 μm, 1000 μm, etc., as exemplary sizes. Preferably, a material with the most uniform particle size distribution is selected, which is beneficial for forming a uniform and complete lithium adsorbent coating layer on its surface, thereby enabling the prepared low-density composite lithium adsorbent to have good dispersibility during use and avoiding agglomeration.

[0032] Specifically, the compressive strength of the solid bubbles is between 1 MPa and 200 MPa, and can be exemplary parameters such as 1 MPa, 10 MPa, 20 MPa, 30 MPa, 50 MPa, 80 MPa, 100 MPa, 150 MPa, and 200 MPa. Higher compressive strength can give the composite material high stability, which is beneficial to improving its service life. The compressive strength of the solid bubbles after loading active substances remains unchanged.

[0033] It should be noted that the present invention uses an alkaline solution to etch and activate the surface of the solid bubble, thereby increasing the surface roughness and providing more modification sites.

[0034] Specifically, in step (1), the present invention uses a strong alkaline solution to etch the surface of the solid bubble, which can not only increase the interface roughness of the solid bubble surface and provide more mechanical sites to facilitate the subsequent loading of lithium adsorbent, but also introduce hydroxyl groups on the surface of the solid bubble to enhance its surface hydrophilicity and reactivity, thereby promoting the modification treatment of the solid bubble surface by the coupling agent and significantly improving the uniformity and stability of the lithium adsorbent grafting on the solid bubble surface.

[0035] Specifically, in step S1, the solid bubble is placed in a strong alkaline solution for surface etching. The strong alkaline solution is an aqueous solution of sodium hydroxide or potassium hydroxide with a concentration of 0.5-5 mol / L, which can be 0.5 mol / L, 1.0 mol / L, 1.5 mol / L, 2.0 mol / L, 2.5 mol / L, 3.0 mol / L, 4.0 mol / L, or 5.0 mol / L. If the concentration of the strong alkaline solution is too high, it will lead to over-etching of the surface, which will not only damage the surface morphology and structural integrity of the solid bubble, but may also reduce its mechanical strength and even cause the particles to break. If the concentration of the strong alkaline solution is too low, the surface of the solid bubble will not be thoroughly cleaned, resulting in poor etching effect, excessive etching time, or failure to etch the solid bubble.

[0036] To promote the etching activation of the solid bubble surface by the strong alkaline solution, the etching temperature of the solid bubble by the strong alkaline solution needs to be controlled between 40-80℃, which can be 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, or 80℃. If the temperature is too low, the etching rate will be too slow, but it cannot be too high either, as it will easily cause the strong alkaline solution to splash.

[0037] To ensure the etching effect, the present invention requires stirring the solution during the etching process and adjusting the time to 1-4 hours, which can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours. If the time is too short, the etching effect will be poor and the roughening treatment of the solid bubble surface will be insufficient. If the time is too long, the solution will damage the surface structure of the solid bubble and will also affect the subsequent loading of lithium adsorbent.

[0038] It should be noted that, in order to improve the etching effect of the strong alkaline solution on the solid bubble while increasing cost and efficiency, the present invention needs to limit the ratio of the strong alkaline solution to the solid bubble to be etched.

[0039] Specifically, in step S1, the surface etching involves placing the solid bubbles in the strong alkaline solution at a solid-liquid ratio of 10~100g / L and stirring. The ratios can be 10g / L, 20g / L, 30g / L, 40g / L, 50g / L, 60g / L, 70g / L, 80g / L, 90g / L, or 100g / L.

[0040] Specifically, in step S2, the present invention uses a coupling agent to modify the activated solid bubbles, preferably a silane coupling agent, and more preferably a silane coupling agent KH550.

[0041] Specifically, in step S2, the mass ratio of the activated solid bubble to the silane coupling agent is 1:0.5~4. If the amount of silane coupling agent is too low, a dense layer cannot be formed on the surface of the solid bubble, which is not conducive to grafting in subsequent steps; if the amount is too high, it may not only form an unstable and uneven grafted layer, but also reduce coupling efficiency and increase economic costs.

[0042] Specifically, in step S2, the modification temperature is 50-80℃, the time is 1-4 h, and the stirring speed is 100-400 r / min. At lower temperatures or shorter times, it is difficult to provide continuous reaction motive force, insufficient to support the formation of a complete and dense monolayer of the silane coupling agent on the surface of the solid bubble; while temperatures exceeding 80℃ or times exceeding 400 r / min will exacerbate the self-condensation side reaction of the silane coupling agent on the surface of the solid bubble, posing a risk of damaging the carrier structure. A low stirring speed will lead to uneven dispersion of the reaction system, but a speed exceeding 400 r / min may damage the integrity of the solid bubble due to excessive shear force.

[0043] It should be noted that after the modified solid bubbles are allowed to stand and cool, the product floating on the surface is removed, washed three times with deionized water and ethanol, and then dried.

[0044] Specifically, in step S3, the crown ether monomer is at least one of 2-hydroxymethyl-12-crown ether-4 (2M12C4), 4-formylbenzo-15-crown ether-5 (4-FB15C5), and dibenzo-14-crown ether-4 (DB14C4), preferably 2M12C4 or 4-FB15C5.

[0045] Specifically, in step S3, the lithium salt is at least one of lithium perchlorate, lithium chloride, and lithium hydroxide; preferably lithium chloride.

[0046] Specifically, in step S3, the solvent is at least one of DMF, dimethyl sulfoxide, and toluene, preferably methanol or DMF.

[0047] Specifically, in step S3, the molar ratio of the crown ether monomer to the lithium salt is 1:1-1.5, preferably 1:1.1-1.3. If the lithium salt is too small, some crown ethers will not be complexed, and lithium ion templated cannot be achieved, reducing the subsequent adsorption performance. If the lithium salt is excessive, the high ionic strength caused by too many ions may affect the polymerization and increase the economic cost.

[0048] Specifically, in step S3, the ratio of the lithium salt to the solvent is 1 mol: (10~15) L. If the solvent is too little, the concentration of the reaction solution system will be too high, easily causing excessive cross-linking and aggregation between crown ether monomers; if the solvent is too much, the contact probability between reactants will decrease, resulting in a slower reaction rate.

[0049] Specifically, in step S3, in order to avoid oxidation of the crown ether monomer and ensure its reactivity, the reaction between the crown ether monomer and the lithium salt is carried out under a nitrogen atmosphere.

[0050] Specifically, in step S3, the reaction temperature between the crown ether monomer and the lithium salt is 20~80℃, the reaction time is 1~4h, and the stirring speed is 200~500 r / min. Too low a temperature or too short a reaction time will result in slow reaction kinetics and incomplete complexation of the crown ether monomer; too high a temperature will cause instability in the reaction system, and an excessively long reaction time will not further improve production efficiency and will increase energy consumption; too slow stirring will lead to uneven mixing of raw materials and poor product uniformity; too fast stirring poses a risk of damaging the solid bubble structure.

[0051] Specifically, in step S3, the mass ratio of the crown ether to the modified solid bubbles is 1:1-2.5. If the mass ratio of solid bubbles is too low, the overall density of the composite adsorbent will increase significantly beyond that of seawater, thus losing its self-floating properties and increasing the difficulty of recovery; if the mass ratio of solid bubbles is too high, the effective adsorbent loading per unit mass of composite adsorbent will be insufficient, resulting in poor economy and applicability.

[0052] Specifically, in step S3, the functional monomer is at least one selected from p-toluenesulfonic acid, acrylic acid (AA), and methacrylic acid (MAA), preferably p-toluenesulfonic acid and / or MAA. The molar ratio of the functional monomer to the crown ether is 10-20:1. Insufficient amount of functional monomer will result in ineffective synergy with the crown ether, while excessive amount will cause over-crosslinking, which may cover the active sites and reduce adsorption performance.

[0053] Specifically, in step S3, the initiator is azobisisobutyronitrile (AIBN), and the molar ratio of the initiator to the crown ether is 0.2-0.5:1. Insufficient initiator dosage will cause slow and incomplete polymerization, while excessive dosage will easily lead to an increase in side reactions.

[0054] Specifically, in step S3, the crosslinking agent is ethylene glycol dimethacrylate (EGDMA) or epichlorohydrin, preferably EGDMA. The molar ratio of the crosslinking agent to the crown ether is 5-10:1. Insufficient crosslinking agent will result in weak and poor crosslinking, making the imprinted vacancies in the material prone to collapse, thus exhibiting poor cycle stability; excessive crosslinking agent will lead to poor mechanical strength of the crosslinked network, making the material prone to deformation.

[0055] Specifically, in step S3, the reaction continues at a temperature of 50-80℃ for 12-24 hours. If the temperature is too low, the initiator decomposes too slowly, resulting in an incomplete reaction or even synthesis failure. If the temperature is too high, the decomposition rate is too fast, which can easily lead to side reactions and affect the purity of the product. If the reaction time is too short, the reaction will be incomplete, and the time process will cause additional energy consumption.

[0056] Specifically, in step S3, the product that floats to the surface after the reaction is collected, solid-liquid separation is performed, the product is washed three times with detergent and then dried to obtain the composite lithium adsorbent precursor.

[0057] More specifically, in step S3, the detergent used to wash the floating product is at least one of deionized water, anhydrous ethanol, and methanol.

[0058] More specifically, in step S3, the drying temperature is 50~80℃, and the drying time is 4~12 h. If the drying temperature or drying time is too short, the residual detergent on the surface cannot be completely removed, affecting the subsequent adsorption structure. If the drying temperature is too high or the drying time is too long, it may result in unnecessary energy consumption.

[0059] Specifically, in step S3, the precursor of the composite lithium adsorbent obtained after the reaction is eluted to obtain a solid bubble composite lithium adsorbent loaded with crown ether.

[0060] More specifically, in step S3, at least one of dilute hydrochloric acid, dilute nitric acid, and dilute sulfuric acid is used to elute the composite lithium adsorbent precursor at a concentration of 0.1~0.5 mol / L. If the concentration is too high, it will cause the framework elements to dissolve and affect the structural stability and cycle life. If the concentration is too low, it will result in complete ion sieve elution and excessively long elution time.

[0061] It should be noted that, in order to extract the lithium ions embedded in the composite adsorbent precursor and obtain a material that can selectively embed lithium ions, the solid-liquid ratio for eluting the precursor obtained in step S2 is 1-50 g / L, which can be 1 g / L, 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, or 50 g / L.

[0062] To improve elution efficiency, the present invention regulates the conditions of the elution process, specifically: elution temperature of 20~60℃, elution time of 2~24h, and stirring speed of 100~600r / min.

[0063] After elution, the floating solid product is washed with deionized water until neutral by solid-liquid separation and then dried again to obtain the coated self-floating lithium adsorbent. The drying temperature is 50~80℃ and the drying time is 4~12 h.

[0064] Another specific embodiment of the present invention discloses a solid bubble lithium adsorbent supported on crown ether prepared by the above method.

[0065] The solid bubble lithium adsorbent of this invention can float on the surface of the liquid phase during the extraction of lithium. The initial lithium adsorption capacity is ≥6mg / g. After 10 cycles of adsorption, the overall recoverability of the material is not less than 96%, and its adsorption capacity retention rate can still be maintained at more than 90% compared with the initial adsorption, showing excellent recyclability, cycle stability and practical value.

[0066] Another specific embodiment of the present invention discloses a method for applying a solid bubble lithium adsorbent to the adsorption and extraction of lithium from salt lake brine. The Li in the salt lake brine... + The concentration of the adsorbent is 0.1-1000 mg / L, the pH is 5-12, the adsorption temperature is 10-60℃, the time is 2-48 h, and the amount of solid bubble lithium adsorbent used is 1-5000 mg / mL. Another specific embodiment of the present invention discloses a method for recovering solid bubble lithium adsorbent, comprising adding the solid bubble adsorbent adsorbed with lithium ions to a desorbent after solid-liquid separation, and then performing lithium desorption treatment until the lithium is completely removed, thereby recovering the solid bubble composite lithium adsorbent.

[0067] Specifically, the desorbent is an acid solution with a concentration of 0.1~1.0 mol / L. If the desorbent concentration is too low, complete lithium extraction cannot be achieved, resulting in a low desorption rate and incomplete regeneration; if the concentration is too high, it may affect the structural stability of the material and significantly shorten the material's cycle life.

[0068] Preferably, the acid is at least one of hydrochloric acid, nitric acid, sulfuric acid, or acetic acid.

[0069] Specifically, the solid-liquid ratio of the desorbent added to the solid bubble adsorbent is 1~50 g / L. Preferably, the desorption treatment temperature is 20~80℃ and the time is 1~24 h. Insufficient adsorbent leads to excessive desorbent, causing unnecessary waste and increasing the environmental burden; excessively high solid-liquid ratio results in particle accumulation, leading to incomplete desorption and reduced resolution; excessively low temperature cannot provide sufficient reaction kinetics, resulting in incomplete desorption; excessively high temperature exacerbates the structural damage of the material caused by acid; and excessively short reaction time cannot achieve complete desorption; excessively long reaction time leads to structural damage and unnecessary energy consumption.

[0070] It should be noted that the present invention recycles and reuses the solid bubble adsorbent that has already adsorbed lithium ions. By adding a desorbent, it can be recycled and reused for the adsorption of lithium ions. The solid bubble adsorbent of the present invention can be well reused, and can be recycled and reused after desorption with acid solution. This convenient recycling and reuse method reduces costs and improves utilization rate. The recovery rate of the solid bubble adsorbent of the present invention is ≥96%.

[0071] Example 1 This embodiment provides a method for preparing a solid bubble lithium adsorbent supported on crown ethers, specifically including the following steps: S1, Weigh 15 g of hollow glass microspheres (density 0.21 g / cm³). 3 The product (with a median particle size of 75 μm and a compressive strength of 120 MPa) was placed in 300 mL of a 0.5 mol / L sodium hydroxide solution and stirred at 200 rpm for 2 h in an 80℃ water bath. After solid-liquid separation, the product was washed with deionized water until neutral and then dried in an oven. S2, Weigh 10 g of the product from step S1 and place it in a 500 mL beaker. Add 150 mL of anhydrous ethanol, 150 mL of pure water and 10 mL of silane coupling agent KH550. Stir at 100 rpm for 2 h in an 80℃ water bath. After solid-liquid separation, wash the product three times with deionized water and anhydrous ethanol and then dry it in an oven. In step S3, 4.8 mmol of 2M12C4 and 4.8 mmol of LiCl were weighed and added to a three-necked flask containing 50 mL of methanol. The stirring speed was set to 300 r / min, and the mixture was stirred at 60 °C for 2 h to allow the crown ether monomer and lithium ions to self-assemble. Then, 1.5 g of the product obtained in step S2, i.e., the modified solid bubbles, was added to the system. After stirring for 10 min, 8 mL of MAA, 6 mL of EGDMA, and 0.24 g of AIBN were added. Nitrogen gas was purged into the system, and the reaction was carried out for 18 h. After the reaction, the product floating on the water surface was removed, washed three times with methanol and deionized water, and dried in a 60 °C oven for 8 h to obtain the crown ether-loaded solid bubble composite lithium adsorbent precursor. An appropriate amount of the precursor was weighed according to a solid-liquid ratio of 10 g / L and eluted in a 0.2 mol / L dilute HCl solution to remove lithium ions. The elution temperature was 30 °C, the elution time was 12 h, and the stirring speed was 200 r / min. r / min; After acid elution, the product is washed with pure water until the washing solution is neutral; it is then dried in a 60℃ oven to obtain the solid bubble composite lithium adsorbent loaded with crown ether.

[0072] Example 2 This embodiment provides a method for preparing a solid bubble composite lithium adsorbent supported on crown ether, specifically including the following steps: S1, Weigh 20 g of hollow glass microspheres (density 0.1 g / cm³). 3 The product (with a median particle size of 186 μm and a compressive strength of 50 MPa) was placed in 250 mL of 0.5 mol / L potassium hydroxide solution and stirred at 200 rpm for 4 h in an 80℃ water bath. After solid-liquid separation, the product was washed with deionized water until neutral and then dried in an oven. S2, Weigh 10 g of the product from step S1 and place it in a 500 mL beaker. Add 150 mL of anhydrous ethanol, 150 mL of pure water and 5 mL of silane coupling agent KH550. Stir at 250 rpm for 3 h in a 60℃ water bath. After solid-liquid separation, wash three times with deionized water and anhydrous ethanol and then dry in an oven. In step S3, 5 mmol of the crown ether functional monomer 4-FB15C5 and 5.2 mmol of LiCl were weighed and added to a three-necked flask containing 60 mL of DMF. The stirring speed was set to 500 r / min, and the mixture was stirred at 50 °C for 3 h to allow the crown ether monomer and lithium ions to self-assemble. Then, 2 g of the product obtained in step S2, i.e., the modified solid bubbles, was added to the system. After stirring for 10 min, 6 mL of MAA, 5 mL of crosslinking agent EGDMA, and 0.18 g of initiator AIBN were added. The temperature was raised to 70 °C, and nitrogen gas was introduced into the system for 12 h. After the reaction, the product floating on the water surface was removed, washed three times with methanol and deionized water, and dried in an oven at 60 °C for 8 h to obtain the crown ether-loaded solid bubble composite lithium adsorbent precursor. An appropriate amount of the precursor was weighed according to a solid-liquid ratio of 10 g / L and eluted in a 0.1 mol / L dilute HCl solution to remove lithium ions. The elution temperature was 30 °C, and the elution time was 12 h. The stirring speed was 200 r / min. After acid elution, the product was washed with pure water until the washing solution was neutral. It was then dried in a 60℃ oven to obtain the crown ether-loaded solid bubble composite lithium adsorbent.

[0073] Example 3 This embodiment provides a method for preparing a solid bubble composite lithium adsorbent supported on crown ether, specifically including the following steps: S1, Weigh 20 g of hollow glass microspheres (density 0.58 g / cm³). 3 The product (with a median particle size of 265 μm and a compressive strength of 24 MPa) was placed in 500 mL of a 5 mol / L sodium hydroxide solution and stirred at 200 rpm for 2 h in a 50℃ water bath. After solid-liquid separation, the product was washed with deionized water until neutral and then dried in an oven. S2, Weigh 10 g of the product from step S1 and place it in a 500 mL beaker. Add 150 mL of anhydrous ethanol, 150 mL of pure water and 20 mL of silane coupling agent KH550. Stir at 200 rpm for 2 h in a 50℃ water bath. After standing and cooling, remove the product floating on the surface, filter it, and wash it three times with deionized water and anhydrous ethanol. Then dry it in an oven. S3, 2 mmol lithium perchlorate (LiClO4), 1.5 mmol DB14C4 and 20 mL DMF were added to a three-necked flask. The stirring speed was set to 500 r / min and stirred at 25 °C for 4 h to allow the functional monomer 2M12C4 and lithium ions to pre-self-assemble. Nitrogen gas was purged and 1 g of modified solid bubbles were added to the above solution. After 15 min, 3 g p-toluenesulfonic acid, 2.5 mL EGDMA and 0.1 g AIBN were added to the above mixture, and the system was kept at 70 °C for 12 h. After the reaction, the product floating on the water surface was removed and washed three times each with methanol and deionized water. It was then dried in a 60℃ oven for 8 h to obtain the precursor of the crown ether-supported solid bubble composite lithium adsorbent. An appropriate amount of the prepolymer was weighed at a solid-liquid ratio of 10 g / L and eluted in a 0.2 mol / L dilute H₂SO₄ solution to remove lithium ions. The elution temperature was 30℃, the elution time was 12 h, and the stirring speed was 200 r / min. After acid elution, the product was washed with pure water until the washing solution was neutral. It was then dried in a 60℃ oven to obtain the crown ether-supported solid bubble composite lithium adsorbent.

[0074] Example 4 This embodiment provides a method for preparing a solid bubble composite lithium adsorbent supported on crown ether, specifically including the following steps: S1, weigh 15 g of fly ash cenospheres (density 0.52 g / cm³). 3 The product (with a median particle size of 755 μm and a compressive strength of 1 MPa) was placed in 300 mL of 0.1 mol / L potassium hydroxide solution and stirred at 200 rpm for 1 h in an 80℃ water bath. After solid-liquid separation, the product was washed with deionized water until neutral and then dried in an oven. S2, Weigh 10 g of the product from step S1 and place it in a 500 mL beaker. Add 150 mL of anhydrous ethanol, 150 mL of pure water and 10 mL of silane coupling agent KH550. Stir at 200 rpm for 2 h in an 80℃ water bath. After solid-liquid separation, wash the product three times with deionized water and anhydrous ethanol and then dry it in an oven. In step S3, 4.8 mmol of 2M12C4 and 5 mmol of LiCl were weighed and added to a three-necked flask containing 50 mL of methanol. The stirring speed was set to 200 r / min, and the mixture was stirred at 50 °C for 2 h to allow the crown ether monomer and lithium ions to self-assemble. Then, 1.5 g of the product obtained in step S2, i.e., the modified solid bubbles, was added to the system. After stirring for 10 min, 8 mL of MAA, 6 mL of EGDMA, and 0.24 g of AIBN were added, and the system was purged with nitrogen for 24 h. After the reaction, the product floating on the water surface was removed, washed three times with methanol and deionized water, and dried in an oven at 60 °C for 8 h to obtain the crown ether-loaded solid bubble composite lithium adsorbent precursor. An appropriate amount of the precursor was weighed according to a solid-liquid ratio of 10 g / L and eluted in a 1.0 mol / L dilute HCl solution to remove lithium ions. The elution temperature was 30 °C, the elution time was 12 h, and the stirring speed was 200 r / min. r / min; After acid elution, the product is washed with pure water until the washing solution is neutral; it is then dried in a 60℃ oven to obtain the solid bubble composite lithium adsorbent loaded with crown ether.

[0075] Example 5 This embodiment provides a method for preparing a solid bubble composite lithium adsorbent supported on crown ether, specifically including the following steps: S1, Weigh 15 g of ceramic bubbles (density 0.90 g / cm³). 3 The sample (with a median particle size of 10 μm and a compressive strength of 200 MPa) was placed in 300 mL of a 2 mol / L sodium hydroxide solution and stirred at 400 rpm for 1 h in a 40℃ water bath. After solid-liquid separation, the product was washed with deionized water until neutral and then dried in an oven. S2, Weigh 10 g of the product from step S1 and place it in a 500 mL beaker. Add 150 mL of anhydrous ethanol, 150 mL of pure water and 25 mL of silane coupling agent KH550. Stir at 200 rpm for 4 h in a 50℃ water bath. After solid-liquid separation, wash the product three times with deionized water and anhydrous ethanol and then dry it in an oven. In step S3, 4.8 mmol of 2M12C4 and 6 mmol of LiCl were weighed and added to a three-necked flask containing 50 mL of methanol. The stirring speed was set to 200 r / min, and the mixture was stirred at 80 °C for 1 h to allow the crown ether monomer and lithium ions to self-assemble. Then, 1.5 g of the product obtained in step S3, i.e., the modified solid bubbles, was added to the system. After stirring for 10 min, 8 mL of MAA, 6 mL of EGDMA, and 0.18 g of AIBN were added, and the system was purged with nitrogen for 12 h. After the reaction, the product floating on the water surface was removed, washed three times with methanol and deionized water, and dried in an oven at 60 °C for 8 h to obtain the crown ether-loaded solid bubble composite lithium adsorbent precursor. An appropriate amount of the precursor was weighed according to a solid-liquid ratio of 10 g / L and eluted in a 0.2 mol / L dilute HCl solution to remove lithium ions. The elution temperature was 30 °C, the elution time was 12 h, and the stirring speed was 200 r / min. r / min; After acid elution, the product is washed with pure water until the washing solution is neutral; it is then dried in a 60℃ oven to obtain the solid bubble composite lithium adsorbent loaded with crown ether.

[0076] Example 6 This embodiment provides an application of a crown ether-supported solid bubble lithium adsorbent in the field of lithium isotope separation, specifically including the following steps: S1, Weigh 15 g of hollow glass microspheres (density 0.21 g / cm³). 3 The product (with a median particle size of 75 μm and a compressive strength of 120 MPa) was placed in 300 mL of a 0.5 mol / L sodium hydroxide solution and stirred at 200 rpm for 2 h in an 80℃ water bath. After solid-liquid separation, the product was washed with deionized water until neutral and then dried in an oven. S2, Weigh 10 g of the product from step S1 and place it in a 500 mL beaker. Add 150 mL of anhydrous ethanol, 150 mL of pure water and 10 mL of silane coupling agent KH550. Stir at 100 rpm for 2 h in an 80℃ water bath. After solid-liquid separation, wash the product three times with deionized water and anhydrous ethanol and then dry it in an oven. In step S3, 4.8 mmol of 2M12C4 and 4.8 mmol of LiCl were weighed and added to a three-necked flask containing 50 mL of methanol. The stirring speed was set to 300 r / min, and the mixture was stirred at 60 °C for 2 h to allow the crown ether monomer and lithium ions to self-assemble. Then, 1.5 g of the product obtained in step S2, i.e., the modified solid bubbles, was added to the system. After stirring for 10 min, 8 mL of MAA, 6 mL of EGDMA, and 0.24 g of AIBN were added. Nitrogen gas was purged into the system, and the reaction was carried out for 18 h. After the reaction, the product floating on the water surface was removed, washed three times with methanol and deionized water, and dried in a 60 °C oven for 8 h to obtain the crown ether-loaded solid bubble composite lithium adsorbent precursor. An appropriate amount of the precursor was weighed according to a solid-liquid ratio of 10 g / L and eluted in a 0.2 mol / L dilute HCl solution to remove lithium ions. The elution temperature was 30 °C, the elution time was 12 h, and the stirring speed was 200 r / min. r / min; After acid elution, the product is washed with pure water until the washing solution is neutral; it is then dried in a 60℃ oven to obtain the solid bubble composite lithium adsorbent loaded with crown ether.

[0077] S4, the prepared lithium adsorbent was placed in a LiCl solution with a lithium concentration of 1.0 g / L at a temperature of 25℃ for 2 h, and the solid-liquid ratio of the lithium adsorbent to the solution was 100 mg / mL. The adsorption was stirred and the adsorbed material was recovered after adsorption. The adsorbent was dissolved using a wet digestion method and then prepared into an aqueous solution. The lithium ion content was then determined. The single-stage separation coefficient of lithium isotopes was calculated using formula (1), where... 6 Li / 7 Li represents the isotopic abundance ratio, and the subscripts s and l represent the solid and liquid phases, respectively. The sample prepared in this embodiment exhibits an isotopic separation factor of 1.08 for lithium chloride, demonstrating excellent separation effects for lithium isotopes. This method could be a safer and more effective alternative to the existing lithium amalgam method. (1)

[0078] Comparative Example 1 The comparative example of preparing activated and modified solid bubbles specifically includes the following steps: Weigh 15 g of hollow glass microspheres (density 0.21 g / cm³). 3A solid bubble (with a median particle size of 75 μm and a compressive strength of 120 MPa) was placed in 200 mL of a 2 mol / L sodium hydroxide solution and stirred at 400 rpm for 1 h in a 40°C water bath. After solid-liquid separation, the product was washed with deionized water until neutral and then dried in an oven. Then, 10 g of the product was weighed and placed in a 500 mL beaker, and 150 mL of anhydrous ethanol, 150 mL of pure water, and 40 mL of silane coupling agent KH550 were added. The mixture was stirred at 400 rpm for 1 h in a 40°C water bath. After cooling, the product floating on the surface was removed, filtered, and washed three times with deionized water and anhydrous ethanol before being dried in an oven to obtain the activated and modified solid bubble.

[0079] Comparative Example 2 The comparative example of preparing crown ether lithium adsorbent specifically includes the following steps: 4.8 mmol of 2M12C4 and 4.8 mmol of LiCl were weighed and added to a three-necked flask containing 50 mL of methanol. The mixture was stirred at 300 r / min for 2 h at 60 °C to allow the crown ether monomer to self-assemble with lithium ions. After stirring for 10 min, 8 mL of MAA, 6 mL of EGDMA, and 0.24 g of AIBN were added, and the system was purged with nitrogen for 18 h. After the reaction, the product was washed three times with methanol and three times with deionized water, and dried in an oven at 60 °C for 8 h. An appropriate amount of the product was weighed at a solid-liquid ratio of 10 g / L and eluted in a 0.2 mol / L dilute HCl solution to remove lithium ions. The elution temperature was 30 °C, the elution time was 12 h, and the stirring speed was 200 r / min. After acid elution, the product was washed with pure water until the washing solution was neutral. The product was then dried in an oven at 60 °C to obtain the crown ether lithium adsorbent.

[0080] Comparative Example 3 This comparative example provides a method for preparing a solid bubble composite lithium adsorbent supported on crown ether, specifically including the following steps: S1, Weigh 10 g of hollow glass microspheres (density 0.21 g / cm³). 3 The sample (with a median particle size of 75 μm and a compressive strength of 120 MPa) was placed in a 500 mL beaker, and 150 mL of anhydrous ethanol, 150 mL of pure water and 10 mL of silane coupling agent KH550 were added. The mixture was stirred at 100 rpm for 2 h in an 80 °C water bath. After standing and cooling, the product floating on the surface was removed, filtered, and washed three times with deionized water and anhydrous ethanol before being dried in an oven.

[0081] In step S2, 4.8 mmol of 2M12C4 and 4.8 mmol of LiCl were weighed and added to a three-necked flask containing 50 mL of methanol. The stirring speed was set to 300 r / min, and the mixture was stirred at 60 °C for 2 h to allow the crown ether monomer and lithium ions to self-assemble. Then, 1.5 g of the product obtained in step S3, i.e., the modified solid bubbles, was added to the system, and the mixture was stirred for 10 min. Then, 8 mL of MAA, 6 mL of EGDMA, and 0.24 g of AIBN were added, and the system was purged with nitrogen for 18 h. After the reaction, the product floating on the water surface was removed, washed three times with methanol and deionized water, and dried in an oven at 60 °C for 8 h. An appropriate amount of the product was weighed according to a solid-liquid ratio of 10 g / L and eluted in a 0.2 mol / L dilute HCl solution to remove lithium ions. The elution temperature was 30 °C, the elution time was 12 h, and the stirring speed was 200 r / min. After acid elution, the product is washed with pure water until the washing solution is neutral. It is then dried in a 60℃ oven to obtain the crown ether-loaded solid bubble composite lithium adsorbent.

[0082] Comparative Example 4 Using the same method as in actual Example 1, except that in step (1), the amount of lithium chloride added is 3 mmol, and finally a solid bubble composite lithium adsorbent loaded with crown ether is obtained.

[0083] Experimental Example (1) Adsorption condition A: The prepared lithium adsorbent is placed in a metal ion Li + Na + K + Mg 2+ The lithium adsorbent was placed in a simulated brine solution at a concentration of 0.5 g / L, with an initial pH of 6.24, a temperature of 25 °C, and an adsorption time of 2 h. The solid-liquid ratio of lithium adsorbent to solution was 10 mg / mL. Adsorption was carried out under stirring. After adsorption was complete, the adsorbed material was recovered and regenerated by desorption with a 0.2 mol / L acid solution. A second adsorption experiment was then conducted under the same conditions. This process was repeated several times to examine the changes in the adsorption performance of the adsorbent material.

[0084] The adsorption capacity and partition coefficient of the adsorbent for lithium are calculated using formulas (2) and (3), respectively: (2) (3) In the formula, Q e C is the adsorption capacity (mg / g), C0 is the initial ion concentration in the solution (mg / L), and C eω is the concentration of ions in the solution after adsorption reaches equilibrium (mg / L), V is the volume of the solution (L), m is the mass of the adsorbent (g), and ω is the mass fraction of the theoretically effective adsorbent in the sample (%). It is the partition coefficient of the adsorbent to other metal ions in the mixed solution, where M represents Na. + K + Mg 2+ .

[0085] (2) Adsorption conditions B: Pure lithium solution with a lithium concentration of 1.0 g / L, temperature of 25℃, adsorption time of 2 h, solid-liquid ratio of lithium adsorbent to solution of 100 mg / mL, dynamic circulation adsorption experiment was conducted by placing the adsorbent in a water tank, and the flow rate was controlled at 2 mL / s using a peristaltic pump. After adsorption was completed, the adsorbed material was recovered and regenerated by desorption with acid solution. The lithium adsorption rate was calculated using formula (4): (4) The changes in the concentrations of various ions in the solution and desorption solution before and after adsorption were measured using ICP-OES. The lithium adsorption performance of the prepared lithium adsorbent was calculated, and the adsorption experimental results are shown in Table 1. Compared with the comparative example, the examples showed relatively better lithium adsorption performance.

[0086] Table 1 Physicochemical and adsorption data of the examples and comparative samples

[0087] In the table above, entries with relevant results indicate that relevant adsorption tests were conducted; entries with no relevant results marked with "-" indicate that no relevant adsorption tests were conducted.

[0088] Figure 1The graph shows the lithium-ion adsorption capacity of the adsorbent samples prepared in Examples 1, 2, and 3 of this invention at different times. As can be seen from the graph, the adsorption capacity of all samples gradually increases with time. This is because the sample surface has many adsorption sites in the initial stage of adsorption, which can rapidly adsorb free lithium ions in the aqueous phase. The samples in Examples 1 and 3, based on the highly uniform dispersion characteristics of the matrix, can achieve a faster adsorption rate than crown ether adsorbents through rapid mass transfer with lithium ions in the aqueous phase. Functional modification further improves the adsorption performance of the sample in Example 1, exhibiting the optimal adsorption capacity. Further investigation of the cycling performance of the samples in Examples 1 and 3 revealed that after ten cycles, the adsorption capacity retention rates were 93.67% and 75.42%, respectively. This is because the surface hydroxylation treatment introduces a large number of hydroxyl groups, providing silanization grafting sites that effectively enhance the interfacial bonding strength, achieving stable crown ether grafting, thus exhibiting better cycling performance and facilitating long-term stable use. Comparing the relevant data of Example 1 and Comparative Example 4, it can be seen that the adsorption performance decreased after reducing the amount of lithium salt. This is because the amount of lithium salt is too low to provide sufficient driving force for all crown ether molecules to complex with lithium ions, resulting in some crown ether cavities not being effectively templated, thus significantly reducing the final adsorption capacity and selectivity of the adsorbent for lithium ions.

[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 changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a solid bubble lithium adsorbent loaded with crown ether, the method comprising: S1: activating a solid bubble with an alkaline solution; S2: modifying the activated solid bubble of step (1) with a coupling agent to obtain a modified solid bubble; S3: reacting a crown ether monomer with a lithium salt in a solvent, adding the modified solid bubble, a catalyst, a crosslinking agent, and an initiator, continuing the reaction, solid-liquid separation, washing, drying, elution, and obtaining the solid bubble lithium adsorbent.

2. The method of claim 1, wherein, In step S1, the solid bubble is one or more of hollow glass beads, hollow glass microspheres, fly ash floating beads, and ceramic bubbles. and / or the density of the solid bubbles is 0.10 to 0.90 g / cm 3 , the particle size is 10 to 1000 μm, and the compressive strength is between 1 MPa and 200 MPa.

3. The method of claim 1, wherein, In step S1, the alkaline solution is a sodium hydroxide or potassium hydroxide aqueous solution with a concentration of 0.5-5 mol / L.

4. The method of claim 1, wherein, In step S1, the activation treatment is performed at a temperature of 40-80℃ for 1-4 h.

5. The method of claim 1, wherein, In step S2, the coupling agent is a silane coupling agent, and the mass ratio of the activated solid bubble to the silane coupling agent is 1:0.5-4.

6. The method of claim 1, wherein, In step S2, the modification is performed at a temperature of 50-80℃ for 1-4 h.

7. The method of claim 1, wherein, In step S3, the crown ether monomer is at least one of 2-hydroxymethyl-12-crown-4, 4-formylbenzo-15-crown-5, and diphenyl-14-crown-4, and the molar ratio of the crown ether monomer to the lithium salt is 1:1-1.

5.

8. The method of claim 1, wherein, In step S3, the mass ratio of the crown ether to the modified solid bubble is 1:1-2.

5. And / or, the temperature for the continued reaction is 50-180℃, and the time is 12-24 h.

9. A solid bubble lithium adsorbent loaded with a crown ether, characterized in that, The solid bubble lithium adsorbent is prepared by the method of any one of claims 1-8.

10. A crown ether loaded solid bubble lithium adsorbent for use in adsorbing lithium extraction from salt lake brine, characterized in that, The solid bubble lithium adsorbent is the solid bubble lithium adsorbent prepared by the method of any one of claims 1-8 or the solid bubble lithium adsorbent of claim 9.

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