Compositions, systems and methods for extracting one or more metals from a solution

Abstract

Disclosed are reagent compositions containing at least one amide extractant capable of selectively extracting one or more metal, compounds thereof, salts thereof or combinations thereof, from an aqueous solution; and optionally at least one modifier and / or diluent. Further disclosed are methods of extracting one or more metals from an aqueous solution, including contacting the aqueous solution with a reagent composition as described above; and extracting the one or more metals, compounds thereof, salts thereof, or combinations thereof, from the aqueous solution into the reagent composition until reaching equilibrium to form a metal depleted aqueous phase and a metal rich organic phase.

Description

COMPOSITIONS, SYSTEMS AND METHODS FOR EXTRACTING ONE OR MORE METALS FROM A SOLUTIONFIELD

[0001] The disclosure relates to compositions, systems and methods for extracting one or more metals (e.g., lithium) from a solution (e.g., an aqueous brine).BACKGROUND

[0002] In the world’s transition to clean energy, electricity storage platforms play an important role. Lithium batteries are at the forefront of electricity storage technologies because inter alia they charge faster, last longer and have a higher power density to provide more battery life in a lighter package than conventional batteries. Lithium storage devices are useful for electrification of the transportation sector, electric vehicles, battery storage for electric utilities and in many other applications to reduce carbon emissions and store electricity.

[0003] Lithium is typically extracted from underground deposits of brine water and ore comprised of compounds containing lithium. Brines from salars and salt lakes, as well as spodumene ores, are the primary sources of lithium, while geothermal brines represent secondary sources. Lithium-containing brine obtained from a source is initially concentrated to a suitable concentration (e.g., about 6,000 ppm Li) for viable recovery. Conventional methods of lithium extraction rely on brine evaporation in open ponds to maximize element concentration for further purification; however, these methods are very slow (evaporation of ponds to the desired level can take up to 24 months) and strongly dependent on region-specific weather conditions that vary throughout the year. When the brine contains a low concentration of magnesium, conventional lithium extraction methods are only able to extract little or no lithium. There is a need for improved systems and methods to recover metals such as lithium from aqueous solutions having low concentrations of magnesium.BRIEF SUMMARY

[0004] Disclosed herein according to various embodiments are reagent compositions, comprising: at least one amide extractant capable of selectively extracting one or more metals, compounds thereof (e.g., compounds other than salts), salts thereof, or combinations thereof, from an aqueous solution; and optionally comprising at least one modifier, at least one diluent, or a combination thereof. The one or more metals may include lithium, magnesium, calcium, boron, potassium, sodium, or combinations thereof. In one or more embodiments, the one ormore metals include a lithium salt, magnesium salt, calcium salt, boron salt, potassium salt, sodium salt or combinations thereof. In various embodiments, the one or more metals include lithium or a lithium salt.

[0005] According to one or more embodiments, the at least one amide extractant comprises an amide compound chosen from the following Formula (I), Formula (II), Formula (III), or combinations thereof:wherein R1, R2, R3, R4, R5, R7, R8, R9, R10and R11is each independently hydrogen, a methyl group, an ethyl group, a straight or branched C3-C20 alkyl group, a C3-C12 cycloalkyl group having a single ring structure, a Cs-Cio aromatic ring group, a C1-C20 alkylphenyl group, a dihydrobenzodi oxene group, a straight or branched C1-C20 alkanol group, a straight or branched C1-C20 alky ldiol group, a straight or branched C3-C20 alkenyl group, a straight or branched C3-C20 alkynyl group, a thiol group, wherein at least one carbon atom of R1, R2, R3, R4, R5, R7, R8, R9, R10and R11may be substituted with a N, O or S, and wherein R6is a bond, a methyl group, an ethyl group, a straight or branched C3-C20 alkyl group, a C3-C12 cycloalkyl group having a single ring structure, a Cs-Cio aromatic ring group, a C3-C20 alkylphenyl group, a straight or branched C3-C20 alkenyl group, a straight or branched C3-C20 alkynyl group, a thiol group, wherein at least one carbon atom of R6may be substituted with N, O or S.

[0006] According to one or more embodiments, the at least one amide extractant may be present in the reagent composition in an amount of greater than 0 wt%, or about 1 wt% to about 99 wt%, or any individual value or sub-range within these ranges, based on the total weight of the reagent composition. In embodiments, a weight ratio of the at least one amide extractantto the at least one modifier is about 1:10 to about 100: 1, or any individual value or sub-range within this range.

[0007] In various embodiments, the reagent compositions further include a diluent such as an alcohol, an organophosphorous solvent, or a combination thereof. Suitable diluents include, but are not limited to, octanol, tri decanol, 2-ethyl-l -hexanol, 3-methyl-l -butanol, isoamyl alcohol, 2-hexyl decanol, octanoic acid, trioctylphosphine oxide (e.g., Cyanex® 923), petroleum distillates solvent (e.g., Orform® SX80), aromatic C9-C10 solvent (e.g., Shellsol® Al 50), a kerosene (e.g., Orform® SX1 1), dibutyl carbitol, dichloromethane, trioctylmethylammonium chloride (e.g., Aliquat 336), chloroform, or a combination of any two or more thereof.

[0008] According to various embodiments, the at least one diluent may be present in the reagent composition in an amount of greater than 0 wt%, or about 1 wt% to about 99 wt%, or any individual value or sub-range w ithin these ranges, based on the total weight of the reagent composition

[0009] In one or more embodiments described herein, the reagent compositions include at least one modifier. Suitable modifiers include one or more functional group having a dipole moment and / or that is attached to a highly polar ionic bond. In embodiments, the at least one modifier comprises an aliphatic component that is attracted to non-polar moieties of the at least one amide extractant. In one or more embodiments, the at least one modifier, includes one or more functional group chosen from a diether, amide, imide, ketone, alcohol, ether, alkyl phosphine, phosphate, ester, phosphonic acid, phosphonic acid, phosphoric acid and / or nitrile. Suitable modifiers include, but are not limited to, 1 ,6-di-t-butoxy hexane, di(ethylene glycol) di butyl ether, 1,4-bis-t-butoxy butane. 2-ethylhexyl succinimide. 4-t-butylcyclohexanone. l-butyl-3- methylimidazolium methyl sulfate, iminodiacetic acid (IDA), dodecanol, 2,2,4-trimethyl-l,3- pentanediol diisobutyrate (TXIB), ethyoxylated isotri decyl phosphate (TDA), cy decanol, 1- methyl-3-octylimidazolium chloride, trihexyltetradecylphosphonium chloride, l-decyl-3- methylimidazolium tetrafluoroborate, 7-ethyl-2-methyl-undecanol, hexyl 3- methylimidazolium chloride, trimethyl nonanol. 4-isopropyl cyclohexanone, t-butyl octyl ether, 3-isopropyl cyclohexanone, 3.3.5-trimethyl cyclohexanone, methyl n-propyl ketone (e.g., Eastman C11 ketone), 5-ethyl-2-nonanone, a mixture of phosphine oxides (e g., Cyanex 923), tributyl phosphate, triisobutyl phosphate, 6-undecanone, heptyl 2-ethylbutyrate, 2- ethylbutyl caproate, 3-(cyclohexyl)-propionitrile, di(2-ethylhexyl)phthalate, tris(2- ethylhexyl)phosphate, ethyl acetate, or a combination of any two or more thereof.

[0010] According to one or more embodiments, then at least one modifier is present in the reagent composition in an amount of greater than 0 wt%, or about 1 wt% to about 99 wt%, based on the total weight of the reagent composition. In embodiments, a weight ratio of the at least one amide extractant to the at least one diluent is about 1 : 10 to about 100: 1, or any individual value or sub-range within this range.

[0011] Further described herein are methods of extracting one or more metals, compounds thereof, salts thereof, or combinations thereof from an aqueous solution, comprising: contacting the aqueous solution with an organic solution comprising a reagent composition according to embodiments herein; and extracting the one or more metals, compounds thereof, salts thereof, or combinations thereof from the aqueous solution into the organic solution until reaching equilibrium to form a metal depleted aqueous phase and a lithium salt rich organic phase.

[0012] According to various embodiments, the aqueous solution is a metal-containing brine, brine from a salar, product stream from a pond evaporation process, product stream from a processing plant, or combinations thereof. In one or more embodiments, the aqueous solution contains one or more lithium salts comprising lithium chloride, lithium sulfate, lithium hydroxide, lithium nitrate or combinations thereof.

[0013] In some embodiments, the methods include contacting the aqueous solution with a magnesium selective reagent composition, a calcium selective reagent composition, a boron selective reagent composition, or a combination thereof, prior to contacting the aqueous solution with the reagent composition to extract the one or more lithium salts. Methods described herein may further comprise contacting the metal depleted aqueous phase with organic solution comprising fresh reagent composition and further extracting the one or more metals, compounds thereof, salts thereof, or combinations thereof from the aqueous solution into the metal rich organic phase until reaching equilibrium. In some embodiments, methods include repeating the further extracting with the organic solution comprising the fresh reagent composition until the metal depleted aqueous phase is free or substantially free of the one or more metals, compounds thereof, salts thereof, or combinations thereof. Methods according to embodiments herein may further include emulsifying the metal rich organic phase. In various embodiments, the methods include separating the metal depleted aqueous phase from the metal rich organic phase. In one or more embodiments, methods include stripping the lithium from the metal rich organic phase.

[0014] In one or more embodiments, about 70% to about 99%, or about 95%, or any individual value or sub-range within these ranges, of the lithium is stripped from the metal rich organicphase. In various embodiments, the overall extraction of lithium from the aqueous solution is greater than about 70%, greater than about 80%, greater than about 90%, greater than about 92%, or about 70% to about 99%, about 80% to about 93, or any individual value or sub-range within these ranges. In one or more embodiments, the selectivity of the reagent composition for lithium over magnesium is about 1 to about 50, about 5 to about 30, or about 10 to about 25.SUMMARY OF THE DRAWINGS

[0015] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like references indicate similar elements.

[0016] FIG. 1 shows a schematic representation of a zwitterionic extractant when contacted with a solution containing inorganic salts forming an inorganic-organic double salt (IODS) can be formed using lithium chloride (LiCl) as an example.

[0017] FIG. 2 is a schematic of a direct metal extraction sy stem for recovering a target metal (e.g., lithium) from an aqueous feed solution (e.g., a brine).Definitions

[0018] Reference throughout this specification to, for example, “one embodiment,” “certain embodiments,” “one or more embodiments” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in one embodiment” or “In one or more embodiments” in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0019] As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, reference to “a depurator vessel” includes a single depurator vessel as well as more than one depurator vessel.

[0020] As used herein, the term “about” in connection with a measured quantity, refers to the normal variations in that measured quantity as expected by one of ordinary skill in the art in making the measurement and exercising a level of care commensurate with the objective of measurement and the precision of the measuring equipment. In certain embodiments, the term “about” includes the recited number ± 10%, such that “about 10” would include from 9 to 11.

[0021] The term “at least about'’ in connection with a measured quantity refers to the normal variations in the measured quantity, as expected by one of ordinary skill in the art in making the measurement and exercising a level of care commensurate with the objective of measurement and precisions of the measuring equipment and any quantities higher than that. In certain embodiments, the term “at least about” includes the recited number minus 10% and any quantity that is higher such that “at least about 10” would include 9 and anything greater than 9. This term can also be expressed as “about 10 or more.” Similarly, the term “less than about” typically includes the recited number plus 10% and any quantity' that is lower such that “less than about 10” would include 11 and anything less than 11. This term can also be expressed as “about 10 or less.”

[0022] Unless otherwise indicated, all parts and percentages are by weight. Weight percent (wt. %), if not otherwise indicated, is based on an entire composition free of any volatiles, that is, based on dry solids content. Parts per million (ppm) unless otherwise indicated is on the basis of weight.

[0023] The term “metal” or “metals” as used herein refers to the recited metal element and includes compounds (i.e.. other than salts) containing the metal, salts containing the metal and / or combinations thereof. For example, “lithium” refers to lithium compounds, lithium salts and lithium-containing molecules.

[0024] The term “trace” or “trace amount” as used herein refers to the amount of a component in a solution being less than about 1 part per million by weight (ppmw).

[0025] The term “substantially free” as used herein refers to trace amounts of a component in a fluid, less than trace amounts of the component in the fluid or a non-detectable amount of the component in the fluid.DETAILED DESCRIPTION

[0026] Embodiments of the disclosure are described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, example features. The features can, however, be embodied in many different forms and should not be construed as limited to the combinations set forth herein; rather, these combinations are provided so that this disclosure will be thorough and complete and will fully convey the scope. The following detailed description is, therefore, not to be taken in a limiting sense.

[0027] Described herein are reagent compositions containing one or more amide extractants for selectively extracting one or more target metals (e.g., lithium), compounds thereof, salts thereof (e.g., lithium chloride), or combinations thereof from a solution (e.g., an aqueous brine).The reagent compositions described herein provide high extraction and stripping performances in, for example, aqueous brines containing about 10 g / L lithium, lithium compounds and / or lithium salts together with magnesium, magnesium compounds and / or magnesium salts dissolved or suspended therein. Reagent compositions as described herein are suitable to extract the one or more metals, compounds thereof, salts thereof, or combinations thereof in a solvent extraction process without the need to centrifuge and / or separate the organic and aqueous phases. In embodiments, reagent compositions as disclosed provide good kinetics in liquid-liquid solvent extraction operations.

[0028] According to one or more embodiments, the reagent compositions include zwitterionic amide extractants for use in methods of solvent extraction of one or more alkali metals (e.g., lithium and / or lithium containing compounds such as lithium salts including lithium chloride). The extractants and methods described herein can be highly selective for one or more target metals or metal containing compounds such as metal salts (e.g., lithium chloride). According to one or more embodiments, it was determined that the reagent compositions as described herein are suitable to concentrate the metal and / or metal compounds (e.g., LiCl) dramatically with a selectivity that was far greater than expected.

[0029] The solvent extraction methods according various embodiments herein are operable using a conventional solvent extraction process and the system is suitable for stripping with water to a relatively high concentration of metal or metal compounds (e.g., lithium chloride) in the recovery solution. It has been found that the extraction of the metals and metal-containing compounds and the production of a recovery stream containing the concentrated metals and / or compounds is suitable for downstream use as battery grade (e.g., lithium salt) production.

[0030] Amide extractants as described herein may be zwitterionic extractants having a positive charge and a negative charge on the same organic molecule. This makes these compounds intra-ion organic salts, and are often self-associating in the bulk organic. When contacted with a solution containing inorganic salts, an inorganic-organic double salt (IODS) can be formed as shown in FIG. 1 using lithium chloride (LiCl) as an example. Without being bound by any particular theory, it is believed that transfer of the LiCl occurs by making an emulsion to increase the surface area. The extractant is suitable to bond with the lithium salt at the interface forming the IODS. The emulsion may be allowed to coalesce once extraction is complete so the phases can be separated. The organic solution is typically washed or scrubbed to remove entrained water or loaded impurities. It is then stripped with water. This is considered an atypical liquid-liquid solvent extraction process due to the lack of an activation / deactivation mechanism using acid / base.

[0031] While most extractants need a diluent or solvent in order to remain low viscosity, zwitterions can work essentially as neat formulations of extractant and modifier. In embodiments, the unloaded formulation is a two-component system: at least one amide extractant; and at least one modifier. The amide extractant and modifier and their respective concentrations may be chosen based on a particular aqueous solution containing one or more target metals, compounds thereof, salts thereof, or combinations thereof.

[0032] Extractants and chemicals useful in the systems and methods described herein can be synthesized at a relatively low cost with low toxicity. Systems and methods according to embodiments are anticipated to be less expensive and product a higher purity of target metal (e.g., lithium) than using conventional adsorption technologies. The inventive systems and methods can be integrated with traditional solvent extraction processes and / or bipolar electrodialysis (BPED) processes to further purify and concentrate the target metal (e.g., lithium).

[0033] Described herein according to one or more embodiments are reagent compositions comprising one or more extractant(s) that are selective for one or more target metals including compounds thereof, salts thereof, and / or combinations thereof. For example, the reagent compositions contain at least one amide extractant suitable to extract lithium and / or lithium salts. Suitable extractants include amide extractants, for example, containing an amide compound and / or an amide base structure including sulfonamides.

[0034] In one or more embodiments, the metal-selective reagent compositions described herein can be a solution of a polar or nonpolar organic / inorganic liquid phase or a mixture of polar and / or nonpolar liquids that contain, for example, C, S, N, O, halides etc. In some embodiments, the reagent compositions contain aliphatic or aromatic amides, diamides, polyamides, diketoamides, thioamides, carbazide, and / or semi-carbazide and may have a density of at least about 0.5 g / L.

[0035] In embodiments described herein, the amide extractant does not use a proton transfer mechanism. Without being bound by any particular theory, it is believed that extractants as described herein work by inducing a zwitterionic charge based on resonance structures. The extractants described herein may be suitable to extract lithium as a salt (e.g., lithium chloride, etc.). In various embodiments, the reagent compositions may be free of an extractant that uses a proton transfer mechanism.

[0036] The one or more target metals or metal compounds may be dissolved and / or dispersed within a solvent (e.g., an aqueous solution). In various embodiments, the solvent is a metal-containing aqueous solution, for example, a metal -containing brine, brine from a salar, product stream from a pond evaporation process, product stream from a processing plant, or combinations thereof. According to various embodiments, the aqueous solution is a brine containing greater than about 60,000 ppm of magnesium, compounds thereof, salts thereof, or combinations thereof, and at least about 150 ppm of lithium, compounds thereof, salts thereof, or combinations thereof.

[0037] In some embodiments, the at least one amide extractant are independently capable of selectively extracting lithium, magnesium, calcium, boron, potassium, or sodium, or combinations thereof. In some embodiments, the at least one amide extractant is capable of selectively extracting one or more lithium compounds, one or more magnesium compounds, one or more calcium compounds, one or more boron compounds, one or more potassium compounds, or one or more sodium compounds, or combinations thereof. For example, suitable extractants may be capable of extracting one or more lithium salt, one or more magnesium salt, one or more calcium salt, one or more boron salt, one or more potassium salt, or one or more sodium salt, or combinations thereof. According to embodiments, suitable extractants are capable of selectively extracting, lithium, one or more lithium compounds such as one or more lithium salts, or combinations thereof. In various embodiments, the at least one amide extractant selectively extracts a lithium salt over one or more magnesium salts, one or more calcium salts, one or more boron salts, one or more potassium salts, or one or more sodium salts, and / or combinations thereof.

[0038] Suitable amide extractants for use in reagent compositions as described herein include one or more amide compound chosen from the following Formula (I), Formula (II), Formula (III), or combinations thereof:wherein R1, R2, R3, R4, R5, R7, R8, R9, R10and R11is each independently hydrogen, a methyl group, an ethyl group, a straight or branched C3-C20 alkyl group, a C3-C12 cycloalkyl group having a single ring structure, a Cs-Cio aromatic ring group, a C1-C20 alkylphenyl group, a dihydrobenzodi oxene group, a straight or branched C1-C20 alkanol group, a straight or branched C1-C20 alky I diol group, a straight or branched C3-C20 alkenyl group, a straight or branched C3-C20 alkynyl group, a thiol group, wherein at least one carbon atom of R1, R2, R3, R4. R5. R7, R8, R9, R10and R11may be substituted with a N. O or S. and wherein R6is a bond, a methyl group, an ethyl group, a straight or branched C3-C20 alkyl group, a C3-C12 cycloalkyl group having a single ring structure, a Ce-Cio aromatic ring group, a C3-C20 alkylphenyl group, a straight or branched C3-C20 alkenyl group, a straight or branched C3-C20 alkynyl group, a thiol group, wherein at least one carbon atom of R6may be substituted w ith N, O or S.

[0039] In some embodiments, at least one amide extractant in the reagent composition is of Formula (I), wherein R1and R2is each independently a straight or branched C3-C8 alkyl and R3is H. In some embodiments, at least one amide extractant is of Formula (II) wherein R4and R7is each independently a straight or branched C3-C8 alkyl, R5and R8are H, and R6is a Cs-Ce cycloalkyl. In one or more embodiments, at least one amide extractant is of Formula (I) wherein R2is a straight or branched C3-C8 alkyl, R3is H and R1is methyl. In some embodiments, at least one amide extractant in the reagent composition is of Formula (I) wherein R2is H, R1and R3is each independently a straight or branched C3-C8 alkyl. In embodiments, at least one amide extractant is of Formula (I) wherein R2is a straight or branched C3-C8 alky l, R3is H, and R1is an ethyl group. In embodiments, at least one amide extractant is of Formula (I) wherein R2is a Ce aromatic ring group, R3is H, and R1is a methyl group. In further embodiments, at least one amide extractant is of Formula (I) wherein R2is H, R3a Ci alkylphenyl group, and R1is a straight or branched C3-C8 alkyl group. In embodiments, at least one amide extractant is of Formula (II) w herein R7, R8and R4are H, R6is a bond, and R5is a straight or branched C3-C8 alkyl. In various embodiments, at least one amide extractant is of Formula (I) wherein R2is a straight or branched C3-C8 alkyl, R3is H and R1is a dihydrobenzodioxene group. In embodiments, at least one amide extractant is of Formula (I) wherein R2is a Ce aromatic ring group, R3is H, and R1is a straight or branched C3-C8 alkyl. In yet further embodiments, at least one amide extractant is of Formula (I), wherein R2and R3are H, and R1is a C3-C8 alky ldiol group. In further embodiments, at least one amide extractant is of Formula (I) wherein R2is an O substituted C3-C8 alkanol, R3is H, and R1is a straight or branched Cs-Cs alkyl. In yet further embodiments, at least one amideextractant is of Formula (III) wherein R10is H and R9and R11is each independently a straight or branched C3-C8 alkyl.

[0040] According to various embodiments, the at least one amide extractant may be present in the reagent composition in an amount of about 5 wt % to about 100 wt%, about 10 wt% to about 90 wt%, about 20 wt% to about 800 wt%, about 30 wt% to about 70 wt%, about 40 wt% to about 50 wt%, about 10 wt% to about 50 wt%, or any individual value or sub-range within these ranges, based on the total weight of the reagent composition. In some embodiments, the amide extractant is present in the reagent composition in an amount of at least about 5 wt%, at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 40 wt%, at least about 50 wt%, or any individual value or subrange within these ranges. In one or more embodiments, the amide extractant is present in the reagent composition in an amount of about 45 wt%, about 46 wt%, about 47 wt%, about 48 wt%, about 49 wt%, about 50 wt%, about 51 wt%, about 52 wt%, about 53 wt%, about 54 wt, or about 55 wt%. In some embodiments, the amide extractant is present in the reagent composition in an amount of about 50 wt%.

[0041] According to one or more embodiments, the reagent compositions described herein further include at least one modifier, at least one diluent, or a combination thereof. “Modifiers” refer to chemical compounds designed to affect the properties of other molecules, materials and / or solutions. “Diluents” refer to one or more substance that is added to the reagent compositions to alter the concentration of other components (e.g., one or more extractant, one or more modifier) contained therein and / or to alter the viscosity of the reagent composition.

[0042] Modifiers as described herein may be used to stabilize the IODS. This can be helpful as the polarity of the organic solvent is not high enough to stabilize the highly ionic character of the IODS. Suitable modifiers for inclusion in reagent compositions as described herein include compounds having one or more functional group with a dipole moment and / or that are attached to a highly polar ionic bond. This may “shield” the ionic moieties and helps to solubilize the IODS. In various embodiments, the at least one modifier has an aliphatic component that is attracted to non-polar moieties of the at least one amide extractant. In various embodiments, the at least one modifier includes one or more functional group chosen from a diether, imide, ketone, alcohol, ether, alkyl phosphine, phosphate, ester, phosphonic acid, phosphonic acid, phosphoric acid and / or nitrile.

[0043] Suitable modifiers for use in reagent compositions as described herein may be chosen from 1,6-di-t-butoxy hexane, di(ethylene glycol) dibutyl ether. 1 ,4-bis-t-butoxy butane, 2- ethylhexyl succinimide, 4-t-butylcyclohexanone, l-butyl-3-methylimidazolium methyl sulfate,iminodiacetic acid (IDA), dodecanol, 2,2,4-trimethyl-l,3-pentanediol diisobutyrate (TXIB), ethoxylatedisotridecyl phosphate (TDA), cy decanol, l-methyl-3-octylimidazolium chloride, trihexyltetradecylphosphonium chloride, l-decyl-3-methylimidazolium tetrafluoroborate, 7- ethyl-2-methyl-undecanol, hexyl 3-methylimidazolium chloride, trimethyl nonanol, 4- isopropyl cyclohexanone, t-butyl octyl ether, 3-isopropyl cyclohexanone, 3,3,5-trimethyl cyclohexanone, methyl n-propyl ketone (e.g., Eastman Cn ketone), 5-ethyl-2-nonanone, a mixture of phosphine oxides (e.g., Cyanex 923), tributyl phosphate, triisobutyl phosphate, 6- undecanone, heptyl 2-ethylbutyrate, 2-ethylbutyl caproate, 3-(cyclohexyl)-propionitrile, di(2- ethylhexyl)phthalate, tris(2-ethylhexyl)phosphate, ethyl acetate, or a combination of any two or more thereof.

[0044] According to various embodiments, the at least one modifier is present in the reagent composition in an amount of about 0 wt% to about 95 wt%, about 5 wt% to about 80 wt%, about 10 wt% to about 80 wt%, about 20 wt% to about 70 wt%, about 30 wt% to about 60 wt%, about 50 wt% to about 90 wt%, or any individual value or sub-range within these ranges, based on the total weight of the reagent composition. In some embodiments, the modifier is present in the reagent composition in an amount of at least about 25 wt%, at least about 30 wt%, at least about 40 wt%, at least about 50 wt%, or any individual value or sub-range within these ranges. In one or more embodiments, the modifier is present in the reagent composition in an amount of about 40 wt%, about 41 wt%, about 42 wt%, about 43 wt%, about 44 wt%, about 45 wt%, about 46 wt%, about 47 wt%, about 48 wt%, about 49 wt%, about 50 wt%. about 51 wt%, or about 52 wt%. In some embodiments, the modifier is present in the reagent composition in an amount of about 50 wt%.

[0045] In various embodiments, the weight ratio of the amide extractant to the modifier in the reagent composition is about 1: 100 to about 100: 1, about 1:90 to about 90: 1, about 1 :80 to about 80: 1, about 1: 70 to about 70: 1, about 1 :60 to about 60: 1, about 1:50 to about 50: 1, about 1 :40 to about 40: 1, about 1 :30 to about 30: 1, about 1:25 to about 25: 1, about 1 :20 to about 20: 1, about 1: 15 to about 15: 1, about 1 :10 to about 10: 1, about 1:5 to about 5: 1, about 1:2 to about 1:2, about 1 : 10 to about 100: 1, or any individual value or sub-range within these ranges. In some embodiments, the weight ratio of the amide extractant to the modifier is at least about 1 : 10, at least about 1:5, at least about 1 :2, at least about 1 : 1, at least about 2: 1, at least about 5: 1, at least about 10: 1, or any individual value or sub-range within these ranges.

[0046] Suitable diluents include, but are not limited to, an alcohol, an organophosphorous solvent, or a combination thereof. In one or more embodiments, the compositions contain organic and inorganic solvents including, but not limited to, tributyl phosphate, alcohols,kerosene, sulfonated kerosene, ionic liquids. In various embodiments, the at least one diluent may be chosen from octanol, tridecanol, 2-ethy 1-1 -hexanol. 3-methyl-l -butanol, isoamyl alcohol, 2-hexyl decanol, octanoic acid, trioctylphosphine oxide (e.g., Cyanex® 923), petroleum distillates solvent (e.g., Orform® SX80), aromatic C9-C10 solvent (e.g., Shellsol® A150), a kerosene (e.g., Orform® SX11), dibutyl carbitol, dichloromethane, trioctylmethylammonium chloride (e.g., Aliquat 336), chloroform, or a combination of any two or more thereof.

[0047] According to various embodiments, the at least one diluent is present in the reagent composition in an amount of about 0 wt% to about 90 wt%, about 5 wt% to about 80 wt%, about 10 wt% to about 70 wt%, about 20 wt% to about 60 wt%, about 40 wt% to about 50 wt%, or any individual value or sub-range within these ranges, based on the total weight of the reagent composition. In one or more embodiments, the diluent is present in the reagent composition in an amount of about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, or about 10 wt%. In some embodiments, the diluent is present in the reagent composition in an amount of about 0 wt% or less than about 1 wt%.Methods of Preparation

[0048] Reagent compositions according to embodiments herein are comprised of an amide extractant and optionally may be combined with at least one modifier and / or at least one diluent. In some embodiments, a diluent is combined with the amide extractant, for example, to provide a target reagent concentration and / or to provide a target viscosity. Suitable reagent concentrations for an amide extractant in a diluent are about 1 wt% to about 99 wt%, or any individual value or sub-range within these ranges. In some embodiments, the viscosity of the amide extractant, alone or in combination, is adjusted by combining the extractant(s) with a diluent while mixing at about 20°C to about 50°C, about 30°C to about 50°C, or any individual value or sub-range within these ranges, to form one or more reagent having a low viscosity' of about 0.1 cP to about 15 cP, or any individual value or sub-range within this range.

[0049] In one or more embodiments, the amide extractant are combined to form an extractant mixture. Each extractant or the extractant mixture may be combined with a modifier while mixing at about 20°C to about 50°C, about 30°C to about 50°C, or any individual value or subrange within these ranges, to form the reagent composition. A diluent may or may not be present and / or combined with the amide extractant and / or the mixture of the extractant with the modifier. As discussed above, the amide extractant may be combined with the modifierover a range of suitable concentrations and ratios to form the reagent composition. The viscosity of the resulting reagent composition may be about 0.1 cP to about 100 cP. or any individual value or sub-range within this range.Systems

[0050] In one or more embodiments, disclosed herein are unified or standalone flow process systems and related methods for direct metal (e.g.. lithium) extraction from aqueous sources (e.g., a brine). In one or more embodiments, systems described herein include recovering a metal from an aqueous solution, comprising: a metal separation and transfer system comprising an adsorbent selective to adsorb a target metal from an aqueous feed solution, the metal separation and transfer system comprising an inlet for a solvent to elute the adsorbent to form an eluate comprising the target metal; an extraction system in fluid communication with the eluate, wherein the extraction system forms a target metal rich solution; and a purification system in fluid communication with the target metal rich solution, wherein the purification system isolates the target metal from the target metal rich solution.

[0051] According to various embodiments, the systems and methods include a liquid-liquid solvent extraction system suitable for extracting one or more target metals (e.g., lithium), compounds thereof, salts thereof (e.g., LiCl), or combinations thereof, from an aqueous steam (e.g., a brine), alone or in combination with one or more of a purification system, a concentration system and / or a conversion system. Additional unit operations and related systems suitable for purifying and / or concentrating solutions within the described systems and methods can include, but are not limited to, electrodialysis reversal (EDR), reverse osmosis, nanofiltration, combined nanofiltration and reverse osmosis, BPED, adsorption / absorption, stripping, or combinations of any two or more thereof.

[0052] Systems and methods according to embodiments herein are suitable to process aqueous solutions (e.g., brines) containing one or more metals. In one or more embodiments, suitable aqueous solutions contain low to high concentrations of magnesium (e.g., about 0 ppm to about 10,000 ppm) in combination with low to high concentrations of lithium (e g., about 1 ppm to about 25.000 ppm). In some embodiments, suitable aqueous solutions contain magnesium at a high concentration (e g., 10,000 ppm) together with a low to high concentration of lithium (e.g., about 1 ppm to about 25,000 ppm). Suitable aqueous solutions, which can be processes by systems and methods described herein additionally can include low to high concentration of calcium (e.g., about 0 ppm to about 5,000 ppm), a low to high concentration of potassium (e.g., about 0 ppm to about 30,000 ppm), a low to high concentration of sodium (e.g., about 0ppm to about 40.000 ppm), and / or a low to high concentration of boron (e.g., about 0 ppm to about 5,000 ppm). Suitable aqueous feed solutions for use in embodiments of the systems and methods and also may include heavy metals.

[0053] According to one or more embodiments, the aqueous feed 202 contains salts of at least about 0.01 v .% Li, at least about 0.01 wt% Mg, at least about 0.01 wt% Na, at least about 0.01 wt% Ca, at least about 0.01 wt% B, and at least about 0.01 wt% K, or any individual values or sub-ranges within these ranges. In some embodiments, the aqueous feed 202 contains salts of about 0.01 wt% to about 10 wt% Li, about 0.01 wt% to about 10 wt% Mg, about 0.01wt% to about 10 wt% Na, about 0.01 wt% to about 10 wt% Ca, about 0.01 wt% to about 10 wt% B, and 0.01 wt% to about 10 wt% K.

[0054] Systems and methods disclosed herein can perform lithium-selective separation via solvent extraction at temperatures of about 0 °C to about 100 °C. Similarly, the inventive systems and methods can perform lithium-selective transfers to downstream processes at about 0 °C to about 100 °C. The concentration of lithium in the transferred fluid can range from about 150 ppm to about 100.000 ppm.

[0055] During solvent extraction processes, the phase break may occur within about 1 minute to about 30 minutes with or without external aids. External aids can include, but are not limited to, heat, fractal mixing, centrifugal separation, and / or membrane separation. The separation operation does not necessarily require acid and base adjustment. Lithium can be stripped off of the lithium-loaded organic solution exiting the solvent extraction system using deionized water at about room temperature to about 50°C. In some embodiments, the strip solution is replenished with fresh reagent composition and recycled to the solvent extraction process to increase the target metal (e.g., lithium) concentration in the strip solution to a high concentration (e.g., about 25,000 ppm Li).

[0056] A system 200 for recovering one or more target metals (e.g., lithium), compounds thereof, salts thereof, or combinations thereof from an aqueous feed solution (e.g., a brine) according to embodiments herein is shown in FIG. 2. An aqueous feed solution containing one or more metals (e.g., a brine) enters a liquid-liquid solvent extraction system 204. A suitable aqueous feed solution 202 contains one or more metals, compounds thereof, salts thereof, or combinations thereof. Suitable metals include, but are not limited to, lithium, magnesium, calcium, potassium, sodium, and / or boron.

[0057] The aqueous feed solution 202 can be a product solution from another operation, an eluate from an adsorption process, a recycle stream from another operation, a product stream from a lithium battery recycling operation, a natural brine and / or a manufactured brine. In oneor more embodiments, the aqueous feed solution contains about 1 ppm to about 25,000 ppm of lithium, about 0 ppm to about 10,000 ppm of magnesium, about 0 ppm to about 5,000 ppm of calcium, about 0 ppm to about 30,000 ppm of potassium, about 0 ppm to about 40,000 ppm of sodium, and / or about 0 ppm to about 5,000 ppm of boron, or any individual value or sub-range within these ranges. In some embodiments, the aqueous feed comprises lithium at a concentration of about 10 ppm to about 25,000 ppm, about 100 ppm to about 20,000 ppm, about 1000 ppm to about 15.000 ppm, about 5.000 ppm to about 12.000 ppm. or any individual value or sub-range within these ranges.

[0058] In various embodiments, the aqueous feed 202 comprises magnesium at a concentration of about 100 ppm to about 10,000 ppm, about 200 ppm to about 8,000 ppm, about 300 ppm to about 5,000 ppm, about 500 ppm to about 2.000 ppm. or any individual value or sub-range within these ranges. In embodiments, the aqueous feed comprises calcium at a concentration of about 0.1 ppm to about 5,000 ppm, about 0.2 ppm to about 4,000 ppm, about 0.4 ppm to about 3,000 ppm, about 0.5 ppm to about 2,000 ppm, or any individual value or sub-range within these ranges. According to various embodiments, the aqueous feed solution 202 can include water, dilute acids, dilute bases or neutral aqueous solution of alkali metal halides, sulfates and / or nitrates, which can build a target metal (e g., Li) concentration of more than 2 wt% at room temperature or higher temperatures.

[0059] In one or more embodiments, the aqueous feed solution 202 contains potassium at a concentration of about 50 ppm to about 30,000 ppm of potassium, about 100 ppm to about 25,000 ppm, about 200 ppm to about 20,000 ppm, about 500 ppm to about 15,000 ppm, about 1,000 ppm to about 10,000 ppm, or any individual value or sub-range within these ranges. The aqueous may contain sodium at a concentration of about 50 ppm to about 40,000 ppm, about 100 ppm to about 30,000 ppm. about 500 ppm to about 20,000 ppm, about 1,000 ppm to about 10,000 ppm, or any individual value or sub-range within these ranges. In yet further embodiments, the aqueous feed may contain boron at a concentration of about 1 ppm to about 5,000 ppm of boron, about 2 ppm to about 4,000 ppm, about 5 ppm to about 3,000 ppm, about 10 ppm to about 2,000 ppm, or any individual value or sub-range within these ranges.

[0060] Once the one or more target metals transfers from the aqueous solution to the organic solution, a metal depleted aqueous solution 206 is formed. The metal depleted aqueous solution 206 may be recycled back to combine with the aqueous feed solution 202 and / or may be sent to another process for purification and / or removal of one or more additional metal, compounds thereof, salts thereof, or combinations thereof using solvent extraction, and / or may be sent to another metal removal process. During solvent extraction 204, phase break occurswithin 1 to 30 minutes with or without external aids to divide the combined solution into the metal depleted aqueous phase 206 and the metal rich organic phase 208. External aids can include, but are not limited to, heat, fractal mixing, centrifugal separation, and / or membrane separation. The solvent extraction operation 204 does not necessarily require acid and base adjustment.

[0061] As the one or more target metals transfer from the aqueous solution to the organic solution, a metal rich organic phase 208 is formed. According to embodiments herein, the inventive reagent compositions may be combined with an organic solvent (e.g., a kerosene) to form the organic solution. The at least one amide extractant in the reagent composition is suitable to selectively extract one or more target metals including compounds thereof, salts thereof, or combinations thereof from the aqueous fee solution 202 into the organic solution. In various embodiments, combining one or more reagent composition with the organic solvent increases the extraction efficiency, selectivity and / or extraction rate for one or more target metal including compounds thereof, salts thereof, and / or combinations thereof.

[0062] In one or more embodiments, the metal rich organic solution 208 contains mass ratios of Mg / Li, Ca / Li. K / Li. Na / Li, Na / Li of less than about 50. or any individual value or sub-range within these ranges. In some embodiments, the metal rich organic solution 208 contains mass ratios of Mg / Li, Ca / Li, K / Li, Na / Li, Na / Li independently about 1 :50 to about 50:1, about 1 :40 to about 40: 1, about 1:30 to about 30: 1, about 1:20 to about 20:1. about 1 : 10 to about 10: 1, about 1 :5 to about 5: 1, about 1 :2 to about 2: 1, or any individual value or sub-range within these ranges.

[0063] In one or more embodiments, the metal rich organic phase may be configured to flow to one or more downstream unit operation processes 210 to recover the one or more target metals that have been extracted from the aqueous solution. In some embodiments, the downstream unit operations 210 are chosen from another solvent extraction, organic / inorganic sorbents, metal organic frameworks / imprinted polymers, ion exchange, liquid membranes, reverse osmosis, nanofiltration, electrodialysis, or combinations thereof. As with the solvent extraction system 204, the one or more downstream unit operations 210 can independently or together for a metal rich solution 212 that optionally can be combined with the metal rich solution 208. Metal rich solution 212, alone or in combination with metal rich solution 208, may be directed to a final processing system 214 to separate the one or more target metals, compounds thereof, salts thereof, or combinations thereof from the metal rich solution 208, 212 to provide a pure metal product 216 (e.g., lithium, a lithium salt, such as LiCl. etc.) suitable for use in other processes and products (e.g., lithium batteries). In one or more embodiments,the post-processed solutions 216 contain lower metal impurities (e.g., Mg, Ca, K, Na, B), compounds thereof, salts thereof, or combinations thereof and / or a higher concentration of the one or more target metals (e.g., Li), compounds thereof, salts thereof, or combinations thereof.

[0064] In one or more embodiments, the metal rich solution 212 contains mass ratios of Mg / Li, Ca / Li, K / Li, Na / Li, Na / Li of less than about 50, or any individual value or sub-range within these ranges. In some embodiments, the metal rich organic solution 212 contains mass ratios of Mg / Li, Ca / Li. K / Li, Na / Li. Na / Li independently about 1:50 to about 50: 1, about 1:40 to about 40:1, about l:30 to about 30: 1, about 1:20 to about 20: 1, about L lO to about 10: 1, about 1:5 to about 5: 1, about 1:2 to about 2:1, or any individual value or sub-range within these ranges.

[0065] In some embodiments, following purification and / or concentration 204, 210, the resulting metal rich solution(s) 208, 212 may be converted into one or more target metal product 216 (e.g., lithium hydroxide, lithium carbonate, etc.) using BPED and / or crystallization in a final processing operation 214. In some embodiments, a post-treatment final processing 214 through an ion transport mechanism such as EDR, reverse osmosis, nanofiltration, BPED, adsorption, absorption, or combinations thereof can be used to regenerate metal depleted solutions 218 exiting the final processing 218 and generate a higher metal concentrate solution.

[0066] In various embodiments, the described systems and methods may regenerate one or more target metal selective separation medium and the target metal selective transferring medium in a continuous flow process for reuse in the solvent extraction system 204 and / or various unit operations 210.

[0067] Systems and methods disclosed herein can perform lithium-selective separation at temperatures of about 0 °C to about 100 °C. Similarly, the inventive systems and methods can perform lithium-selective transfers at about 0 °C to about 100 °C. The concentration of lithium in the transferred fluid can range from about 0 ppm to about 100,000 ppm.

[0068] According to various embodiments, the one or more target metals, compounds thereof, salts thereof, or combinations thereof can be stripped off of the metal rich organic solution 208, 212 from the solvent extraction system 204 and / or the one or more downstream unit operations 210 using deionized water at about room temperature to about 50°C. The strip solution can be recycled to increase the lithium concentration in the strip solution to high concentration (e.g., about 25,000 ppm Li).Methods of Use

[0069] Further described herein are methods of using the inventive reagent compositions. In one or more embodiments described are methods for recovering a metal from an aqueous solution, comprising: adsorbing a target metal from an aqueous solution onto an adsorbent selective for the target metal; eluting the adsorbent to form an eluate comprising the target metal; extracting the target metal from the eluate to form a target metal rich solution; and purifying the target metal rich solution to isolate the target metal from the target metal rich solution.

[0070] Reagent compositions according to embodiments herein are suitable for use in a liquidliquid solvent extraction process. In such solvent extraction processes, an aqueous feed solution (e.g., a lithium-containing brine) enters the system and is contacted with an organic solution. In various embodiments, a large organic to aqueous ratio may be needed to extract a target metal, compound thereof, salt thereof, or combinations thereof (e.g., lithium, lithium salt, lithium chloride, etc.) as the molar ratio of the extractant to the target metal may be about 1 : 1.

[0071] The aqueous solution may be a metal-containing brine (e.g., a lithium-containing brine), brine from a salar. product stream from a pond evaporation process, product stream from a processing plant, or combinations thereof. In one or more embodiments, the aqueous feed solution contains lithium, magnesium, calcium, boron, potassium, sodium, or combinations thereof. In embodiments, the aqueous feed solution comprises a lithium salt, magnesium salt, calcium salt, boron salt, potassium salt, sodium salt, or combinations thereof. In various embodiments, the aqueous feed solution comprises lithium or a lithium salt. The one or more target metals, compounds thereof, salts thereof, or combinations for extraction using the described methods may be lithium chloride, lithium sulfate, lithium hydroxide, lithium nitrate, or combinations thereof. According to various embodiments, the aqueous solution is a brine containing greater than about 60,000 ppm of magnesium, compounds thereof, salts thereof, or combinations thereof, and at least about 150 ppm of lithium, compounds thereof, salts thereof, or combinations thereof.

[0072] According to one or more embodiments, the aqueous solution may be contacted with a magnesium selective reagent composition, a calcium selective reagent composition, a boron selective reagent composition, or combinations thereof, prior to contacting the aqueous solution with the reagent composition to extract the one or more metals. Removing magnesium, calcium, and / or boron metals, compounds thereof, salts thereof, or combinations thereof, may improve the selectivity of a downstream lithium, compounds thereof, salts thereof, or combinations thereof solvent extraction process.

[0073] According to embodiments herein, the inventive reagent compositions may be combined with an organic solvent (e.g., a kerosene) to form the organic solution. The at least one amide extractant in the reagent composition is suitable to selectively extract one or more target metals including compounds thereof, salts thereof, or combinations thereof from the aqueous fee solution 202 into the organic solution. In various embodiments, combining one or more reagent composition with the organic solvent increases the extraction efficiency, selectivity and / or extraction rate for one or more target metal including compounds thereof, salts thereof, and / or combinations thereof. Once the one or more target metals transfer from the aqueous solution to the organic solution, a metal depleted aqueous solution 206 is formed. The metal depleted aqueous solution 206 may be recycled back to combine with the aqueous feed solution 202 and / or may be sent to another process for purification and / or removal of one or more additional metal, compounds thereof, salts thereof, or combinations thereof using solvent extraction, and / or may be sent to another metal removal process.

[0074] As the one or more target metals transfer from the aqueous solution to the organic solution, a metal rich organic phase is formed. In one or more embodiments, the metal rich organic phase may be configured to flow to one or more downstream processes to recover the one or more target metals that have been extracted from the aqueous solution.

[0075] In one or more embodiments, the methods include stripping the one or more metals from the metal rich organic phase. The stripping of the reagent can be accomplished with water. Following stripping, the metal depleted organic solvent may be returned to the solvent extraction process for further contact with incoming aqueous feed. The metal depleted organic solvent is replenished with fresh reagent composition to ensure efficiency of the continuous process. In some embodiments, the concentration of lithium salt (e.g., lithium chloride) can be increased to at least 20,000 ppm at which point the stripping efficiency drops below 90%. This does not limit the concentration of the strip solution but may alter the amount of extractant necessary to keep extraction efficiency in an effective range. According to various embodiments, about 70% to about 99%, or at least about 95%, or any individual value or subrange within these ranges of the one or more metals is stripped from the metal rich organic phase.

[0076] According to various embodiments, further described herein are methods of extracting one or more metals comprising compounds thereof, salts thereof, or combinations thereof from an aqueous solution. The methods include contacting the aqueous solution with the reagent composition as described herein. As discussed above, the reagent composition may be contained in an organic solvent to form an organic solution. Upon contact between the aqueoussolution and the organic solution containing at least one amide extractant, the method further include extracting the one or more metals, compounds thereof, salts thereof, or combinations thereof from the aqueous solution into the organic solution containing the reagent composition until reaching equilibrium to form a metal depleted aqueous phase and a metal rich organic phase. In further embodiments, the methods include separating the metal depleted aqueous phase from the metal compound rich organic phase.

[0077] According to various embodiments, the methods may further include contacting the metal depleted aqueous phase with fresh reagent composition and further extracting the one or more metals, compounds thereof, salts thereof, or combinations thereof, from the aqueous solution into the metal rich organic phase (or fresh organic solution) until reaching equilibrium. This process may be repeated to further extract more target metal(s) from the aqueous phase using fresh reagent composition until the metal compound depleted aqueous phase is free or substantially free of the one or more target metals, compounds thereof, salts thereof, or combinations thereof.

[0078] In some embodiments, the methods further include emulsifying the metal rich organic phase. Emulsifying the organic phase can increase the surface area of the extractants to provide more bonding sites for the amide extractant to bond with the one or more target metals, compounds thereof, salts thereof, or combinations thereof.

[0079] The above methods may provide an overall extraction of the one or more metals, compounds thereof, salts thereof, or combinations thereof, from the aqueous solution of greater than about 70%, greater than about 80%, greater than about 90%, greater than about 92%, or about 70% to about 99%, or about 80% to about 93%, or any individual value or sub-range within these ranges. According to one or more embodiments, selectivity for the inventive reagent compositions is very’ high for lithium over sodium, potassium, magnesium, calcium, boron, and sulfate. In some embodiments, emulsions may be controlled to keep selectivity high, which may be addressed by controlling viscosity of the organic. Selection of suitable equipment maintain low entrainment mixing also may assist in emulsion control. In various embodiments, the target metal is lithium, lithium-containing compounds, lithium salts, or combinations thereof, and the selectivity of the amide extractant, or a mixture thereof for lithium over magnesium is about 1 to about 50, about 5 to about 30, or about 10 to about 25.ILL USTRA TIVE EXAMPLESExample 1 - Contact evaluations of amide extractants with aqueous brine solutions

[0080] Many small scale extraction and strip tests were conducted with synthetic brine as well as several real brines to understand the effect of brine compositions, temperature, structure of amide extractants, and different formulations with amide extractants. Kinetics studies were also conducted.Table 1 - Multiple contact test results between an aqueous brine and inventive amide extractant

[0081] As shown in Table 1, multiple contact test results with an aqueous brine containing a high concentration of lithium, compounds thereof, and / or salts thereof and ahigh concentration of magnesium showed good extraction and stripping performance.Table 2 - Analyses of strip solutions

[0082] Table 2 shows analyses of the strip solutions from the experiment conducted with respect to Table 1. As shown in Table 2, the strip solutions show suitable Li / divalent and Li / monovalent selectivity.Table 3 - Extraction results for aqueous brine containing a high concentration of lithium and a high concentration of magnesium

[0083] As shown in Table 3, the extraction results for the high lithium-high magnesium aqueous brine at different temperatures showed acceptable extraction uptake can still be achieved at higher temperatures.Table 4 - One-stage extraction results for other aqueous brines with an amide extractant

[0084] As shown in Table 4, the one-stage extraction results for other aqueous brines also shoed suitable performance.Table 5 - Strip results for other aqueous brines

[0085] As shown in Table 5, the strip results for other aqueous brines showed acceptable selectivity.Table 6 - Multiple contact test results with an aqueous brine containing a high concentration of magnesium

[0086] As shown in Table 6, an aqueous brine containing a high concentration of magnesium encountered multiple contacts with the extractant showing suitable extraction and stripping performance.Table 7 - Stripping efficiencies with aqueous solution having no to a high concentration of salt as the lithium-transferring liquid media

[0087] As shown in Table 7, the stripping efficiencies using an aqueous solution having no to a high concentration of salt as the lithium-transferring liquid media show suitable performance.Table 8 - Results when other extractants were used with a synthetic brine

[0088] Table 8 shows the extraction results when other extractants were used to extract lithium from a synthetic brine solution.Example 2 - Building Li concentrations in strip solutions

[0089] To increase the concentration of Li in a strip solution, an organic solution containing an amide extractant of Formula (I) and a tributyl phosphate modifier was contacted with a high concentration Li-containing strip solution. The organic to aqueous solvent ratios (O:A) were varied and each contact occurred for one (1) hour using a shaker (low setting). The stripping temperature was elevated for the organic solution. Nuclear magnetic resonance (NMR) wasused to measure the amount of Li in collected aqueous samples. In this experiment, a Li- loaded organic solution was not repeatedly stripped with a strip solution to build the Li-rich electrolyte. Instead, a poor electrolyte having varying lithium concentrations was used to strip the organic. Table 9 contains the results of those stripping experiments.Table 9 - Strip tests after one extraction stage, beginning with no Li to a high Li concentration in the strip solution

[0090] The elevated stripping temperature aided in both the effectiveness of the stripping process and the viscosity of the solution. Concentrating the stripping solution up to about 25000 ppm Li can be achieved with the amide extractant.Example 3 - Degradation of amide extractants

[0091] Neat amide reagents were stirred in a closed vessel with a brine (i. e. , water) over a 19- week period. The reagent concentration in samples were determined using gas chromatography analysis. The reagent concentration did not change over the 19-week period. This indicates that there was no loss of reagent due to degradation. Since entrainment constantly occurs in a solvent extraction system, the reagent is still lost from the system; however, because degradation of the amide reagents is so low, no negative effects are expected. Without being bound by any particular theory, it is believed that a reagent would have to degrade by about 30-40% over 20 weeks for there to be an impact during the solvent extraction process.

[0092] While acid catalyzed hydrolysis is still a possibility- in systems where the brine is below a pH of 3, the amide extractant is resistant to degradation. The inventive amide extractants are resistant to degradation even when the acid concentration is relatively high at temperatures below 50°C.Example 4 - Kinetic studies with a brine using El in Ml

[0093] Kinetic studies of an organic solution containing 50% v / v of an amide extractant of Formula (I) and 50% v / v of tributyl phosphate modifier were performed. Extraction and strip experiments were conducted in a mixer. Extraction experiments were performed at an O: A of 5: 1 for one (1) hour at varying temperatures and mixing speeds. Stripping experiments were performed at an O:A of 5: 1 using deionized water for one (1) hour at 50-55°C and at varying mixing speeds. NMR was used to measure the amount of Li in aqueous samples.

[0094] The composition of the brine feed used in this Example is provided in Table 10.Table 10 - Composition of the brine feed

[0095] The results showed a dramatic increase in extraction kinetics as a function of. It was determined that the rate of stirring did not appreciably affect the kinetics. There may be some benefit to using a solvent extraction system that minimizes or reduces entrainment after separation of the emulsion that forms between the organic and aqueous phases. Column solvent extraction, for instance, is used when extraction efficiency is not appreciably impacted by the stirring rate.

[0096] The extraction efficiency was inversely proportional to the temperature. This was surprising and unexpected. In traditional solvent extraction processes, extraction is typically aided by higher temperatures and sometimes stripping is inhibited by higher temperatures. The results of this experiment worked in an opposite manner. The difference in extraction between 25°C and 35°C was dramatic. The efficiency was closer to the same value in the first several minutes of mixing before steady state was reached.

[0097] For extraction conducted at room temperature, moderate (-1000 rpm) to high (-1700 rpm) mixing speeds showed better kinetics than low mixing speed (-500 rpm), with equilibrium reached within 5 minutes. Higher temperatures resulted in faster equilibration time. For stripping conducted at 50-55°C, a higher stripping efficiency could be obtained at a high mixing speed (-1700 rpm), but surprisingly equilibrium was achieved at a slower rate. An emulsion was also observed at a high mixing speed.Example 5 - Performance of amide extractants in a low concentration magnesium- containing brine

[0098] Organic solutions containing varying amide extractants were contacted, at room temperature for one (1) hour, using a shaker (low setting), with different synthetic or real brines having low to no magnesium, or spiked with magnesium, to different O:A ratios. For some samples, NMR was used to measure the Li and Na concentrations in aqueous samples, while the rest were measured using inductively coupled plasma (ICP) analysis.

[0099] Table 11 shows the composition of the feed solutions for various low concentration magnesium-containing brines. Table 11 shows the selectivity data for the extractions while Table 12 shows the extraction and strip data for the experiments.Table 11 - Compositions of the low to no Mg feed, and Mg-spiked feed utilizedTable 12 - Various amide extractants tested in a low concentration Mg-containing brine or a synthetic brine

[0100] Some organic reagents were pre-treated with a concentrated Mg solution prior testing and some brines were spiked with Mg. The improved performance in spiked brine is indicated in bold.Table 13 - Multiple extraction experimental data from an amide extractant El of Formula (I) tested in Brine A. Fresh organic and the same raffinate were used per contact.

[0101] For many of the amide extractants evaluated, low to no extraction was observed in a low concentration magnesium-containing brine and a low concentration magnesium- containing synthetic brine. The percent (%) extraction in most amide extractants tested did not surpass about 10% per contact. Improved extraction with these formulations was achieved when the brine was spiked with high amounts of magnesium, or moderate amounts of Mg in a high ionic strength solution. Therefore, it was determined that magnesium plays a role in the extraction performance of amide extractants.Example 6 - Performance of amide extractants in real and synthetic Brine F

[0102] Various amide extractant formulations were tested with real and synthetic Brine F. Different modifiers were also tested. The organic was contacted with the Intrepid brine or synthetic Intrepid brine at an O / A ratio of 5:1 for 1 hour at room using a mixer (500-1000 ppm) / shaker (low setting). NMR was used to measure Li values in aqueous samples, while ICP was used to measure other elements.

[0103] Table 14 shows the composition of the feed solutions for the real and synthetic Brine F used in this example.Table 1 - Composition of the feed tested in these experiments

[0104] Extractant El provided adequate loading of lithium with no measurable loss of aqueous.The data for the extraction and strip experiments is shown in Table 15.Table 2 - Summary of data for extraction and strip experiments of using varying extractants in real or synthetic Brine F

[0105] Various amide extractant formulations were able to extract >50% lithium from real or synthetic Brine F. One formulations displayed mild aqueous volume loss after extraction contact, suggesting entrainment. There w as no difference in performance between real and synthetic Brine F w as observed.

[0106] The foregoing description discloses example embodiments of the disclosure. Modifications of the above-disclosed assemblies, apparatus, and methods which fall within thescope of the disclosure will be readily apparent to those of ordinary skill in the art. Accordingly, while the present disclosure has been disclosed in connection with example embodiments, it should be understood that other embodiments may fall within the scope of the disclosure, as defined by the following claims.

[0107] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessanly limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

CLAIMSWhat is claimed is:

1. A reagent composition, comprising: at least one amide extractant capable of selectively extracting one or more metals, compounds thereof, salts thereof, or combinations thereof, from an aqueous solution; and optionally comprising at least one modifier, at least one diluent, or a combination thereof.

2. The reagent composition of claim 1, wherein the one or more metals comprise lithium, magnesium, calcium, boron, potassium, sodium, or combinations thereof.

3. The reagent composition of claim 1 or 2, wherein the one or more metals comprise a lithium salt, magnesium salt, calcium salt, boron salt, potassium salt, sodium salt or combinations thereof.

4. The reagent composition of any preceding claim, wherein the one or more metals comprise lithium or a lithium salt.

5. The reagent composition of any preceding claim, wherein the at least one amide extractant comprises an amide compound chosen from the following Formula (I), Formula (II),Formula (III), or combinations thereof:wherein R1, R2, R?, R4, R5, R7, R8, R9, R10and R11is each independently hydrogen, a methyl group, an ethyl group, a straight or branched C3-C20 alkyl group, a C3-C12 cycloalkyl group having a single ring structure, a Cs-Cio aromatic ring group, a C1-C20 alkylphenyl group, a dihydrobenzodi oxene group, a straight or branched C1-C20 alkanol group, a straight or branched C1-C20 alky I diol group, a straight or branched C3-C20 alkenyl group, a straight or branched C3-C20 alkynyl group, a thiol group, wherein at least one carbon atom of R5, R6, R7, R8. R9. R10and R11may be substituted with a N, O or S, and wherein R6is a bond, a methyl group, an ethyl group, a straight or branched C3-C20 alkyl group, a C3-C12 cycloalkyl group having a single ring structure, a Ce-Cio aromatic ring group, a C3-C20 alkylphenyl group, a straight or branched C3-C20 alkenyl group, a straight or branched C3-C20 alkynyl group, a thiol group, wherein at least one carbon atom of R12may be substituted with N, O or S.

6. The reagent composition of any preceding claim, further comprising an alcohol, an organophosphorous solvent, or a combination thereof.

7. The reagent composition of any preceding claim, further comprising at least one modifier, wherein the at least one modifier comprises one or more functional group having a dipole moment and / or that is attached to a highly polar ionic bond.

8. The reagent composition of any preceding claim, further comprising at least one modifier, wherein the at least one modifier comprises an aliphatic component that is attracted to non-polar moieties of the at least one amide extractant.

9. The reagent composition of any preceding claim, comprising the at least one modifier, wherein the at least one modifier comprises one or more functional group chosen from a diether, amide, imide, ketone, alcohol, ether, alkyl phosphine, phosphate, ester, phosphonic acid, phosphonic acid, phosphoric acid and / or nitrile.

10. The reagent composition of any preceding claim, further comprising: at least one modifier, wherein the at least one modifier is chosen from 1,6-di-t-butoxy hexane, di(ethylene glycol) dibutyl ether, 1,4-bis-t-butoxy butane, 2-ethylhexyl succinimide, 4-t-butylcyclohexanone, l-butyl-3-methylimidazolium methyl sulfate, iminodiacetic acid (IDA), dodecanol, 2,2,4-trimethyl-l,3-pentanediol diisobutyrate (TXIB), ethyoxylatedisotridecyl phosphate (TDA), cy decanol, l-methyl-3-octylimidazolium chloride, trihexyltetradecylphosphonium chloride, 1 -decyl-3-methylimidazolium tetrafluoroborate, 7- ethyl-2-methyl-undecanol, hexyl 3-methyhmidazolium chloride, trimethyl nonanol, 4- isopropyl cyclohexanone, t-butyl octyl ether, 3-isopropyl cyclohexanone, 3,3,5-trimethyl cyclohexanone, methyl n-propyl ketone (e.g., Eastman Cn ketone), 5-ethyl-2-nonanone, a mixture of phosphine oxides (e.g., Cyanex 923), tributyl phosphate, triisobutyl phosphate, 6- undecanone, heptyl 2-ethylbutyrate. 2-ethylbutyl caproate, 3-(cyclohexyl)-propionitrile. di(2- ethylhexyl)phthalate, tris(2-ethylhexyl)phosphate, ethyl acetate, or a combination of any two or more thereof; and / or at least one diluent, wherein the at least one diluent comprises, octanol, tridecanol, 2- ethyl-1 -hexanol, 3-methyl-l -butanol, isoamyl alcohol. 2-hexyl decanol, octanoic acid, trioctylphosphine oxide (e.g., Cyanex® 923), petroleum distillates solvent (e.g., Orform® SX80), aromatic C9-C10 solvent (e.g., Shellsol® A150), a kerosene (e.g., Orform® SX11), dibutyl carbitol, dichloromethane, trioctylmethylammonium chloride (e.g., Aliquat 336), chloroform, or a combination of any two or more thereof.

11. The reagent composition of any preceding claim, comprising the at least one amide extractant in an amount of greater than 0 wt%, or about 1 wt% to about 99 wt%, based on the total weight of the reagent composition.

12. The reagent composition of any preceding claim, comprising at least one modifier and / or diluent in an amount of greater than 0 wt%, or about 1 wt% to about 99 wt%, based on the total weight of the reagent composition.

13. The reagent composition of any preceding claim, comprising at least one modifier and / or diluent, wherein a weight ratio of the at least one amide extractant to the at least one modifier and / or diluent is about 1: 10 to about 100: 1.

14. A method of extracting one or more metals, compounds thereof, salts thereof, or combinations thereof from an aqueous solution, comprising: contacting the aqueous solution with an organic solution comprising the reagent composition of any preceding claim; andextracting the one or more metals, compounds thereof, salts thereof, or combinations thereof from the aqueous solution into the organic solution until reaching equilibrium to form a metal depleted aqueous phase and a lithium salt rich organic phase.

15. The method of claim 14, wherein the aqueous solution is a metal-containing brine, brine from a salar, product stream from a pond evaporation process, product stream from a processing plant, or combinations thereof. optionally, wherein the aqueous solution is contacted with a magnesium selective reagent composition, a calcium selective reagent, a boron selective reagent composition, or both, prior to contacting the aqueous solution with the reagent composition to extract the one or more lithium salts.

16. The method of claim 14 or 15, wherein the one or more lithium salts comprised in the aqueous solution comprise lithium chloride, lithium sulfate, lithium hydroxide, lithium nitrate or combinations thereof.

17. The method of any one of claims 14 to 16, further comprising contacting the metal depleted aqueous phase with organic solution comprising fresh reagent composition and further extracting the one or more metals, compounds thereof, salts thereof, or combinations thereof from the aqueous solution into the metal rich organic phase until reaching equilibrium, and optionally repeating the further extracting with the organic solution comprising the fresh reagent composition until the metal depleted aqueous phase is free or substantially free of the one or more metals, compounds thereof, salts thereof, or combinations thereof.

18. The method of any one of claims 14 to 17, further comprising emulsifying the metal rich organic phase.

19. The method of any one of claims 14 to 18, further comprising separating the metal depleted aqueous phase from the metal rich organic phase.

20. The method of any one of claims 14 to 19, further comprising stripping the lithium from the metal rich organic phase. optionally, wherein about 70% to about 99%. or about 95% of the lithium is stripped from the metal rich organic phase.

21. The method of any one of claims 14 to 20. wherein the overall extraction of lithium from the aqueous solution is greater than about 70%, greater than about 80%, greater than about 90%, greater than about 92%, or about 70% to about 99%, or about 80% to about 93.

22. The method of any one of claims 14 to 21, wherein the selectivity of lithium over magnesium is about 1 to about 50. about 5 to about 30, or about 10 to about 25.

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