Methods and compositions for recovery of lithium from solutions with nanoparticles

Abstract

To provide a method for recovering metal ions.SOLUTION: There is provided a method for recovering metal ions, comprising the steps of: providing a first medium configured to adsorb the metal ions, the first medium comprising nanoparticles, the nanoparticles comprising a polystyrene coating and a crown ether; exposing a solution comprising the metal ions to the first medium to form a second medium enriched with the metal ions and liquid depleted of the metal ions; extracting the metal ions from the second medium; and magnetically separating the second medium from the liquid.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] In some embodiments, the present disclosure relates to isolating lithium from a water source.

Background Art

[0002] Lithium and lithium salts have many uses, such as in pharmaceuticals, ceramics, metallurgy, fireworks, military applications, etc. Due to the rapid increase in recent efforts towards renewable energy, the demand for lithium as a raw material for rechargeable lithium-ion batteries, such as those used in portable electronic devices and electric vehicles, is increasing.

[0003] Most of the world's lithium is obtained by collecting brine from underground pools, putting the brine in ponds, and then evaporating the ponds with solar heat to leave the salt content. Since the mining of lithium ore is much more costly and not economical, this method is currently the most widespread. Solar evaporation is cheaper than the direct mining of lithium ore, but the products obtained by solar evaporation are not pure and additional processing is required to separate lithium salts from other salts contained in the brine.

[0004] It is desirable to selectively recover high-purity lithium salts from brine in a stable form.

Summary of the Invention

[0005] According to one aspect, the method includes coating nanoparticles with styrene monomer, polymerizing the styrene monomer to form polystyrene-coated nanoparticles, and attaching crown ether to the polystyrene-coated nanoparticles to form a lithium adsorption medium. The method can include exposing a lithium-ion-containing liquid to the lithium adsorption medium to form a lithium-rich adsorption medium and a lithium-depleted liquid, and extracting lithium ions from the lithium-rich adsorption medium to form the extracted lithium ions and a regenerated lithium adsorption medium.

[0006] According to one aspect, a lithium adsorption medium for recovering lithium ions from a lithium-ion-containing liquid includes polystyrene-coated nanoparticles and a crown ether. The lithium adsorption medium is prepared by a process including coating the nanoparticles with a styrene monomer, polymerizing the styrene monomer to form polystyrene-coated nanoparticles, attaching the crown ether to the polystyrene-coated nanoparticles to form the lithium adsorption medium, exposing the lithium-ion-containing liquid to the lithium adsorption medium to form a lithium-rich adsorption medium and a lithium-depleted liquid, and extracting lithium ions from the lithium-rich adsorption medium to form the extracted lithium ions and a regenerated lithium adsorption medium.

[0007] In one example, the nanoparticles have a surface area of about 10 square meters to about 5,000 square meters per gram. The nanoparticles can include a surface area of about 10 square meters to about 500 square meters per gram. The nanoparticles can include an iron material such as magnetic iron. The nanoparticles can include non-magnetic iron. The nanoparticles can include iron, ferrous iron, and iron oxide. The crown ether can include dibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, and diaza-18-crown-6 ether.

[0008] According to one aspect, the method includes separating the extracted lithium ions from the regenerated lithium adsorption medium. In some embodiments, the lithium-rich adsorption medium is magnetically separated from the lithium-depleted liquid. Extracting lithium ions from the lithium-rich adsorption medium may be performed by treating the lithium-rich adsorption medium with a weak acid. The weak acid can include one or more of carbonic acid, acetic acid, phosphoric acid, hydrofluoric acid, oxalic acid, and combinations thereof.

[0009] According to one aspect, the method includes drying the precipitated lithium salt to form a dried lithium salt and separating the lithium-rich adsorbent medium from the lithium-depleted liquid by centrifugation. In some embodiments, the method includes separating the lithium-rich adsorbent medium from the lithium-depleted liquid by centrifugation. Polymerization can provide preferred attachment sites for the crown ether by restricting interference between the oxygen of the crown ether and the nanoparticles for lithium ion adsorption. Polymerization allows the removal of lithium ions from the lithium-rich adsorbent medium using nanoparticles under acidic conditions without decomposing the nanoparticles or while restricting the decomposition of the nanoparticles. Extraction includes exposing the lithium-rich adsorbent medium to water containing carbon dioxide. The extracted lithium ions can precipitate to form a precipitated lithium salt, where the precipitated lithium salt can include lithium carbonate, lithium silicate, lithium oxalate, and combinations thereof. Coating includes adding nanoparticles to a solution containing a styrene monomer and a free radical initiator.

[0010] In some embodiments, a method for generating a lithium adsorbent medium includes coating nanoparticles with a styrene monomer, polymerizing the styrene monomer to form polystyrene-coated nanoparticles, and attaching dibenzo-12-crown-4-ether to the polystyrene-coated nanoparticles to form a lithium adsorbent medium.

[0011] According to some embodiments, a lithium adsorption medium for recovering lithium ions from a lithium ion-containing liquid is provided. The lithium adsorption medium can include iron-containing nanoparticles, polystyrene coating the surface of the nanoparticles, and crown ether attached to the polystyrene. The iron can include magnetic iron, non-magnetic iron, and combinations thereof. The crown ether can include dibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5-ether, diaza-15-crown-5-ether, dibenzo-18-crown-6-ether, and diaza-18-crown-6-ether. In some embodiments, at least about 75% of the surface of the nanoparticles is coated with polystyrene. According to some embodiments, at least about 95% of the surface of the nanoparticles is coated with polystyrene.

Brief Description of the Drawings

[0012] Some embodiments of the present disclosure will be understood by referring in part to the present disclosure and the accompanying drawings.

Figure 1

Mode for Carrying Out the Invention

[0013] In some embodiments, the present disclosure relates to methods and compositions for recovering lithium from a solution using nanoparticles. The solution may be a naturally occurring salt source. The methods and compositions can selectively extract lithium salts from an aqueous salt solution. Aqueous salt solutions include those obtained from seawater, salt lakes, shallow groundwater veins associated with salt lakes or playas, geothermal brines, and deep brines of sedimentary basins. For example, brines can be obtained from Death Valley, California, and Argentina. Selectively extracting lithium salts has the advantage over existing extraction methods of not requiring further separation from other salts such as sodium and potassium salts. Further, the described nanoparticles can be regenerated to reduce nanoparticle manufacturing costs and waste. In some embodiments, magnetic nanoparticles enable, preferably, magnetic separation of the nanoparticles from the brine when lithium is sequestered from the brine. Magnetic separation of nanoparticles from a fluid can be used with high throughput without the need for filters that clog and need to be replaced, which is advantageous compared to conventional filtration methods. The magnetic particles can include steel materials, whether or not in a magnetic state. Iron particles can be extracted by exposure to a magnetic field. Iron particles in a magnetic state can be extracted by exposure to another steel material and / or a magnetic field.

[0014] Figure 1 shows a flowchart of a method for recovering lithium ions from a lithium ion-containing liquid. As shown in Figure 1, the method 100 includes a step 102 of mixing nanoparticles, styrene monomer, and a radical initiator. These elements can be mixed in a glass or metal container and can be mixed using an overhead stirrer, magnetic stir bar, shaking, and combinations thereof. The mixing 102 can be performed in an aqueous solution. In some embodiments, the mixing 102 can be performed in other solvents including diethyl ether, hexane, dichloromethane, toluene, ethanol, methanol, ethyl acetate, acetone, and mixtures thereof. While mixing the nanoparticles, styrene monomer, and radical initiator (102), the styrene monomer coats the surface of the nanoparticles via intermolecular forces including van der Waals forces, dipole-dipole interactions, and hydrogen bonds.

[0015] In the method 100, the nanoparticles can include any metal including iron, magnetic iron, non-magnetic iron, and combinations thereof. For example, the nanoparticles can include any allotrope, iron(II) oxide, iron(III) oxide, and iron dioxide. The nanoparticles can have a surface area of from about 10 square meters to about 5,000 square meters per gram. Preferably, the nanoparticles can have a surface area of about 100 square meters per gram, or about 500 square meters per gram. The inventors have found that a surface area of from about 100 square meters to about 500 square meters per gram advantageously provides a number of attachment sites for lithium to facilitate efficient recovery while providing nanoparticles of a size that facilitates capture of the nanoparticles. The radical initiator can include benzoyl peroxide, tert-butyl peroxide, a methyl radical source, a benzoyloxy radical, methyl ethyl ketone peroxide, acetone peroxide, peroxydisulfate, a halogen peroxide, an azo compound such as azobisisobutyronitrile (AIBN), and combinations thereof.

[0016] As shown in FIG. 1, in some embodiments, the method 100 includes a step 104 of polymerizing a monomer. The polymerization 104 of the monomer includes activating a radical initiator to initiate a polymerization process of a styrene monomer to form polystyrene-coated nanoparticles. The activation includes heating a free radical initiator or inducing radical formation to initiate the polymerization of the styrene-based monomer. The polymerization can be carried out in an aqueous solution containing water or in a solvent such as diethyl ether, hexane, dichloromethane, toluene, ethanol, methanol, ethyl acetate, acetone, and mixtures thereof. In some embodiments, at least about 75% of the surface area of the nanoparticles is coated with polystyrene. The inventors have discovered that if the coating rate of the surface area of the nanoparticles is too low, the styrene monomer is folded, blocking the sites where the crown ether can attach. In a preferred embodiment, at least about 75%, more preferably all, of the surface area of the nanoparticles is coated with polystyrene. By sufficiently coating the surface area of the nanoparticles with polystyrene, sites where the crown ether binds with high yield are advantageously provided. When the polystyrene coating rate is low, the sites where the crown ether binds are reduced, and the metal ion binding ability of the nanoparticles decreases. The higher the polystyrene coating rate of the nanoparticles, the higher the binding yield of the crown ether on the polystyrene, thereby forming more crown ether sites for binding metal ions on the nanoparticles.

[0017] As shown in FIG. 1, the method 100 includes a step 106 of adding a crown ether to polystyrene-coated nanoparticles to form a metal ion adsorption medium such as a lithium ion adsorption medium. The crown ether can bind to the polystyrene-coated nanoparticles, and as a result, the crown ether can advantageously bind to metal salts including lithium, sodium, potassium, aluminum, cesium, magnesium, and combinations thereof. Crown ethers such as dibenzo-12-crown-4-ether can bind to the polystyrene-coated nanoparticles via the dibenzo moiety of the crown ether, and as a result, a crown ether moiety available for binding metal salts such as lithium can be left. The crown ether can bind to the polystyrene-coated nanoparticles via covalent bonds, π-stacking, van der Waals forces, dipole interactions, and combinations thereof. In some embodiments, the crown ether includes dibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, or diaza-18-crown-6 ether. In some embodiments, dibenzo-15-crown-5 ether and diaza-15-crown-5 ether can be used to bind sodium metal ions. Methods and compositions using dibenzo-18-crown-6 ether and diaza-18-crown-6 ether can be used to bind potassium metal ions. The addition 106 of the crown ether to the polystyrene-coated nanoparticles may be performed in an aqueous solution containing water, or in a solvent such as diethyl ether, hexane, dichloromethane, toluene, ethanol, methanol, ethyl acetate, acetone, and mixtures thereof.

[0018] As shown in FIG. 1, the method 100 includes a step 108 of separating the metal ion adsorption medium from the solvent and the components used to produce it. The separation 108 can be performed by filtration, centrifugation, magnetization, and combinations thereof. After performing the separation 108, the separated metal ion adsorption medium can be washed with a solvent containing water to remove unbound monomers or crown ethers. Thereafter, in the method 100, an aqueous salt solution can be added to the metal ion adsorption medium (110) so that the metal ion adsorption medium can adsorb one or more metal ions from the aqueous salt solution to form a metal-rich adsorption medium and a metal-depleted liquid. For example, the method 100 includes a step of exposing a lithium ion adsorption medium to an aqueous salt solution rich in lithium to form a lithium-rich adsorption medium and a lithium-depleted liquid.

[0019] According to some embodiments, when magnetic nanoparticles are used, the method 100 includes a step 112 of using a magnet to separate the metal ion-depleted solution from the metal-rich adsorption medium of the magnetic metal. Thereby, desired metal ions such as lithium are selectively isolated via the nanoparticles from other metal ions remaining in the aqueous salt solution. To remove the metal ions from the metal-rich adsorption medium of the magnetic metal ions, the metal ion adsorption medium can be mixed with an acidic solution (114) to form the extracted metal ions and the regenerated metal ion adsorption medium. For example, a lithium ion adsorption medium can be mixed with an acidic solution (114) to form the extracted lithium ions and the regenerated metal adsorption medium. The acidic solution preferably includes weak acids such as carbonic acid, acetic acid, phosphoric acid, hydrofluoric acid, oxalic acid, and combinations thereof. Although it is also possible to use strong acids, they may damage the styrene-coated nanoparticles and limit the ability to regenerate the nanoparticles.

[0020] According to some embodiments, the method 100 includes a step 116 of separating the regenerated metal ion adsorbing medium from the extracted metal ions. Separation includes filtration, centrifugation, magnetization, and combinations thereof. The regenerated metal ion adsorbing medium may be regenerated multiple times (120) in an iterative process to recover lithium from a single batch of lithium ion-containing liquid and remove more lithium from that batch, or may be used to remove lithium from multiple batches of lithium ion-containing liquid. In some embodiments, the lithium ion adsorbing medium may be used in place to adsorb lithium from a single batch of lithium ion-containing liquid and then transported to another place to isolate lithium from the formed lithium-rich adsorbing medium. Further, all steps of the method 100 may be performed in one place.

[0021] As shown in FIG. 1, the method 100 includes a step 118 of precipitating the extracted metal ions to form a precipitated metal salt. For example, the method 100 includes a step 118 of precipitating the extracted lithium ions to form a precipitated lithium salt, and the precipitated lithium salt includes lithium carbonate, lithium silicate, lithium oxalate, and combinations thereof. To precipitate the metal salt, a carbonate, silicate, or oxalate source can be used. After precipitating the metal salt (118), the metal salt can be separated from the aqueous solvent via a filtration or centrifugation process (122). The separated aqueous solvent is discarded (124), and the separated metal salt may be dried (126). For example, the lithium salt can be dried (126) via heat, under vacuum, and combinations thereof. The lithium salt can be dried via a heat treatment process including calcination in the absence or limited supply of air or oxygen. In some embodiments, calcination may be advantageous if salt decomposition or contamination can occur.

[0022] According to some embodiments, the method can be used to make a metal adsorption medium for recovering metal ions from a metal ion-containing liquid. For example, the present disclosure relates to a lithium ion adsorption medium for recovering lithium ions from a lithium ion-containing liquid. The lithium ion adsorption medium includes nanoparticles containing ions, nanoparticles coated with polystyrene, and crown ethers attached to the polystyrene. Iron includes magnetic iron, non-magnetic iron, iron(II) oxide, iron(III) oxide, iron dioxide, and combinations thereof. Crown ethers include dibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, diaza-18-crown-6 ether. The metal adsorption medium can selectively bind the desired metal ions. Selectivity can be defined as follows: Selectivity = ((moles of target metal ions #) / (moles of unwanted metal ions #)) × 100%

[0023] Inorganic nanomaterials have unique physical properties. In this application, a combination of nanoparticles, coating procedures, and the use of crown ethers for achieving the recovery of lithium from a liquid are described. It is difficult to separate lithium ions from a stream of cations including alkali metals such as sodium and potassium. The selective functional group dibenzo-12-crown-4-ether has a high selectivity for lithium. Magnetic nanoparticles are coated or covered with polystyrene by polymerizing styrene on the surface of the magnetic nanoparticles. The coating of the magnetic nanoparticles with polystyrene provides for the attachment of dibenzo-12-crown-4-ether via the benzene ring of the crown ether, whereby the cyclic ether can be utilized to adsorb lithium cations.

[0024] Iron nanoparticles are covered by polymerizing styrene monomer on the surface of the iron nanoparticles and then attaching crown ether via adsorption of the benzene ring of the dibenzo-12-crown-4-ether ring.

[0025] The nanoparticles are added to a solution containing a free radical initiator and styrene monomer. The nanoparticles may be separated using the magnetic properties of the nanoparticles or other particle separation techniques such as centrifugation or filtration. Then, the styrene monomer is polymerized to coat the nanoparticles. Next, a crown ether is added as a liquid having a freezing point above 16°C and a boiling point below 70°C. This material is stirred so that the crown ether adsorbs onto the styrene polymer coating.

[0026] The crown ether-rich magnetic nanoparticles are added to a liquid containing lithium ions. This may be either a slurry or a solid. The crown ether-coated particles preferentially adsorb lithium from salt water or the liquid. Then, the nanoparticles can be removed from the liquid stream using their magnetic properties or industrial techniques such as filtration or centrifugation.

[0027] Thereafter, the lithium-containing nanoparticles are extracted and the lithium is put into solution. The extractant can be one of several acids or water treated with a weak acid such as carbonic acid, acetic acid, phosphoric acid, hydrofluoric acid, oxalic acid, and combinations thereof. Then, the dissolved lithium is precipitated using carbonate, silicate, or oxalate ions.

[0028] As will be appreciated by those skilled in the art having the benefit of this disclosure, other equivalent or alternative compositions and methods for recovering lithium from a solution using nanoparticles, as well as systems, can be envisioned without departing from the description contained herein. For this reason, the methods of carrying out this disclosure as illustrated and described should be construed as exemplary.

[0029] One of ordinary skill in the art can make various changes to the steps of the method or the shape, size, number and / or arrangement of the components without departing from the scope of the present disclosure. For example, the number of crown ethers can be changed. In some embodiments, the crown ethers may be replaceable. The replaceability enables the separation of various types of salts. Each of the disclosed methods and method steps can be performed in any order based on some embodiments, in relation to other disclosed methods or method steps. When the verb "may" is used, it is intended to convey an optional state and / or permissive condition, but unless otherwise specified, its use is not intended to imply a lack of feasibility. When open terms such as "have" or "include" are used, one of ordinary skill in the art who benefits from the present disclosure will understand that the disclosed features or steps can optionally be combined with additional features or steps. Such a selection may not be exercised, and in fact, in some embodiments, the disclosed systems, compositions, devices and / or methods can also exclude other features or steps beyond those disclosed herein. Elements, compositions, devices, systems, methods and method steps not described may be included or excluded as desired or as required. One of ordinary skill in the art can make various changes in the methods of preparing and using the compositions of the present disclosure and in the methods of the present disclosure.

[0030] Also, when a range is given, the disclosed endpoints can be treated as exact values and / or approximate values as needed or as required by a particular embodiment. When an endpoint is an approximate value, the degree of flexibility may vary proportionally to the order of magnitude of the range. Further, in some embodiments, it may be desirable to combine the endpoints of a range well.

[0031] All or part of a method or composition for recovering lithium from a solution having nanoparticles can be configured and arranged to be disposable, repairable, replaceable, and / or substitutable. Their equivalents and alternatives are intended to be included within the scope of the present disclosure, along with obvious changes and modifications. Accordingly, the foregoing disclosure is not intended to limit the scope of the present disclosure as indicated by the appended claims, but is intended to be exemplary.

[0032] The title, summary, background art, and headings of the invention are provided in accordance with the rules and / or for the convenience of the reader. They do not admit the scope and content of the prior art, nor do they include limitations applicable to all embodiments of the disclosure.

Claims

1. A method for recovering lithium ions from a lithium ion-containing liquid, comprising: coating the nanoparticles with a styrene monomer; polymerizing styrene monomers to form polystyrene-coated nanoparticles; attaching a crown ether to the polystyrene coated nanoparticles to form a lithium adsorption medium; exposing the lithium ion-containing liquid to a lithium sorption medium to form a lithium-rich sorption medium and a lithium-depleted liquid; extracting lithium ions from the lithium-rich sorption medium to form extracted lithium ions and a regenerated lithium sorption medium.

2. 10. The method of claim 1 , The method, wherein the nanoparticles have a surface area of ​​from about 10 square meters per gram to about 5,000 square meters per gram.

3. 10. The method of claim 1 , The method, wherein the nanoparticles have a surface area of ​​about 100 square meters per gram to about 500 square meters per gram.

4. 10. The method of claim 1 , The method, wherein the nanoparticles comprise an iron material.

5. 5. The method of claim 4, The method further comprising the step of magnetically separating the lithium-rich sorption medium from the lithium-depleted liquid.

6. 10. The method of claim 1 , The method, wherein the nanoparticles comprise non-magnetic iron.

7. 10. The method of claim 1 , The method, wherein extracting lithium ions from the lithium-rich sorption medium comprises treating the lithium-rich sorption medium with a weak acid.

8. 8. The method of claim 7, The method, wherein the weak acid comprises at least one of carbonic acid, acetic acid, phosphoric acid, hydrofluoric acid, oxalic acid, and combinations thereof.

9. 10. The method of claim 1 , The method further comprising the step of separating the extracted lithium ions from the regenerated lithium sorption medium.

10. 10. The method of claim 9, The method further comprising precipitating the extracted lithium ions to form precipitated lithium salts, wherein the precipitated lithium salts comprise at least one of lithium carbonate, lithium silicate, lithium oxalate, and combinations thereof.

11. 11. The method of claim 10, The method further comprising drying the precipitated lithium salt to form a dry lithium salt.

12. 10. The method of claim 1 , The method of claim 1, wherein the crown ether comprises at least one of dibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, and diaza-18-crown-6 ether.

13. 12. The method of claim 11, The method according to claim 1, wherein the crown ether comprises dibenzo-12-crown-4-ether.

14. 10. The method of claim 1 , The method further comprising the step of separating the lithium-rich adsorption medium from the lithium-depleted liquid by centrifugation.

15. 10. The method of claim 1 , The method, wherein the polystyrene-coated nanoparticles have a stability such that the polystyrene-coated nanoparticles do not degrade when exposed to acidic conditions.

16. 10. The method of claim 1 , The method wherein the extraction comprises exposing the lithium-rich sorption medium to water containing carbon dioxide.

17. 10. The method of claim 1 , The method, wherein the coating comprises adding the nanoparticles to a solution comprising a styrene monomer.

18. 10. The method of claim 1 , The polymerization involves adding a free radical initiator to styrene monomer; The method of claim 1, wherein the free radical initiator comprises at least one of benzoyl peroxide, tert-butyl peroxide, a methyl radical source, benzoyloxy radical, methyl ethyl ketone peroxide, acetone peroxide, peroxydisulfates, halogen peroxides, azo compounds such as azobisisobutyronitrile, and combinations thereof.

19. 1. A method for producing a lithium sorption medium, comprising the steps of: coating the nanoparticles with a styrene monomer; polymerizing styrene monomers to form polystyrene-coated nanoparticles; and attaching dibenzo-12-crown-4-ether to the polystyrene-coated nanoparticles to form a lithium adsorption medium.

20. A lithium adsorption medium for recovering lithium ions from a lithium ion-containing liquid, comprising: Nanoparticles including an iron material; Polystyrene coating the surface of the nanoparticles; A lithium adsorption medium comprising a crown ether attached to polystyrene.

21. 21. The lithium adsorption medium according to claim 20, A lithium adsorption media, wherein the ferrous material comprises at least one of magnetic iron, non-magnetic iron, and combinations thereof.

22. 21. The lithium adsorption medium according to claim 20, A lithium adsorption medium, wherein the crown ether comprises at least one of dibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, and diaza-18-crown-6 ether.

23. 23. The lithium adsorption medium according to claim 22, A lithium adsorption medium, wherein the crown ether comprises dibenzo-12-crown-4-ether.

24. 24. The lithium adsorption medium according to claim 23, A lithium adsorption medium further comprising a lithium ion attached to the dibenzo-12-crown-4-ether.

25. 21. The lithium adsorption medium according to claim 20, A lithium adsorption medium, characterized in that about 75% or more of the surface of the nanoparticles is covered with polystyrene.

26. 21. The lithium adsorption medium according to claim 20, A lithium adsorption medium, characterized in that about 95% or more of the surface of the nanoparticles is covered with polystyrene.

27. A lithium adsorption medium for recovering lithium ions from a lithium ion-containing liquid, comprising: the lithium adsorption medium comprises polystyrene-coated nanoparticles and a crown ether; The lithium adsorption medium is coating the nanoparticles with a styrene monomer; polymerizing styrene monomers to form polystyrene-coated nanoparticles; attaching a crown ether to the polystyrene coated nanoparticles to form a lithium adsorption medium; exposing the lithium ion-containing liquid to a lithium sorption medium to form a lithium-rich sorption medium and a lithium-depleted liquid; extracting lithium ions from the lithium-rich sorption medium to form extracted lithium ions and a regenerated lithium sorption medium; 2. A lithium adsorption medium, comprising:

28. 28. The lithium adsorption medium of claim 27, A lithium adsorption media, wherein the nanoparticles comprise at least one of magnetic iron, non-magnetic iron, and combinations thereof.

29. 28. The lithium adsorption medium of claim 27, A lithium adsorption medium, wherein the crown ether comprises at least one of dibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, and diaza-18-crown-6 ether.

30. 30. The lithium adsorption medium of claim 29, A lithium adsorption medium, wherein the crown ether comprises dibenzo-12-crown-4-ether.

31. 28. The lithium adsorption medium of claim 27, A lithium adsorption medium, characterized in that about 75% or more of the surface of the nanoparticles is covered with polystyrene.

32. 28. The lithium adsorption medium of claim 27, A lithium adsorption medium, characterized in that about 95% or more of the surface of the nanoparticles is covered with polystyrene.

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