Compositions, systems and methods for adsorbing at least one metal from a solution

Abstract

Disclosed are systems and methods for adsorbing a metal from a solution. The systems include an inlet in fluid communication with an aqueous solution containing at least one metal, at least one impurity metal, or combinations thereof. The systems further include an adsorption unit containing an adsorbent and a mixing element, wherein the adsorbent is suitable to adsorb the at least one metal or the at least one impurity metal. Further disclosed are methods of adsorbing a metal from a solution by contacting an aqueous solution containing at least one metal, at least one impurity metal, or combinations thereof with an adsorbent while mixing to adsorb the at least one metal or the at least one impurity metal.

Description

COMPOSITIONS, SYSTEMS AND METHODS FOR ADSORBING AT LEAST ONEMETAL FROM A SOLUTIONFIELD

[0001] The disclosure relates to compositions, systems and methods for adsorbing at least one target metal or at least one impurity metal from a solution.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] Typically, lithium is extracted from underground deposits of brine water and ore made 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. Classical 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. Newer technologies based on precipitation, adsorption, solvent extraction and membranes can be used for brine concentration and may increase theeconomic viability of minerals extracted from seawater and other geothermal brines. However, there is a need for improved compositions and methods for increasing the net transfer of lithium and other metals using an adsorbent.BRIEF SUMMARY

[0004] Disclosed herein according to various embodiments are systems for adsorbing a metal from a solution, comprising: an inlet in fluid communication with an aqueous solution comprising at least one metal, at least one impurity metal, or combinations thereof; and an adsorption unit comprising an adsorbent and a mixing element, wherein the adsorbent is suitable to adsorb the at least one metal or the at least one impurity metal. In various embodiments, the aqueous solution comprises a brine, a metal product stream, a stream exiting a direct metal extraction process, a purified and concentrated brine, a stream existing a pond system, a feed stream to a metal recovery plant, water, sea water, brackish water, a raffinate stream, an impurity rich stream from a metal extraction process, an aqueous waste stream from a battery recycling process, or combinations thereof. In some embodiments, the at least one metal comprises lithium, calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof. In various embodiments, the at least one impurity metal comprises calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof.

[0005] In various embodiments, the at least one metal comprises lithium in an amount of 0 ppm to about 1,200 ppm, sodium in an amount of about 0 ppm to about 30,000 ppm, potassium in an amount of about 0 ppm to about 20,000 ppm, magnesium of about 0 ppm to about 4,000 ppm, calcium in an amount of about 2,000 ppm, boron in an amount of about 0 ppm to about 2,000 ppm, or combinations thereof, or any individual values or sub-ranges within these ranges. In one ormore embodiments, the at least one impurity metal comprises sodium in an amount of about 0 ppm to about 30,000 ppm, potassium in an amount of about 0 ppm to about 20,000 ppm, magnesium of about 0 ppm to about 4,000 ppm, calcium in an amount of about 2,000 ppm, boron in an amount of about 0 ppm to about 2,000 ppm, or combinations thereof, or any individual values or subranges within these ranges.

[0006] In various embodiments, the adsorbent is selective for the at least one metal or the at least one impurity metal. According to embodiments, the adsorbent is suitable to intercalate the at least one metal as compared to other metals at a ratio of 10: 1, optionally wherein the at least one metal comprises lithium, compounds thereof, salts thereof, or combinations thereof. In one or more embodiments the adsorbent is in the form of sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, resin, pellets, particles coated with a chemical matrix, sheets, crystalline structures, or combinations of any two or more thereof. Suitable adsorbents include aluminum trihydroxide, boron trihydroxide, chromium trihydroxide, molybdenum trihydroxide, lanthanum trihydroxide, rhodium trihydroxide, thulium trihydroxide, zeolite molecular sieve, date pits impregnated with cellulose nanocrystals and ionic liquid, functionalized titanate nanotubes, polymeric porous microspheres with crown ether, granulated chitosan-lithium manganese oxide, manganese-based spinel compounds, modified activated carbon with multiple MnCh nanocomposite ratios, natural and / or synthetic zeolites applying poly(acrylic acid), MnO2-0.4H2O ion sieve, 1 D LiMmCh nanorods, nano-lithium ion sieves, intercalated compositions thereof, or combinations of any two or more thereof.

[0007] According to various embodiments, the adsorbent is supported on a plurality of substrates, optionally, wherein the plurality of substrates comprises sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, or combinations of any two or more thereof.In embodiments, the plurality of substrates comprises carbon, a polymer, silica, alumina, or combinations of any two or more thereof.

[0008] In one or more embodiments, the mixing element comprises baffles, a paddle mixer, vortex mixer, impeller mixer, close clearance impeller mixer, helical ribbon impeller, double helical ribbon impeller, screw impeller, coil impeller mixer, propeller mixer, or combinations thereof. In some embodiments, the adsorbent and at least a portion of the mixing element are received within a vessel. In one or more embodiments, the adsorbent is dispersed in the aqueous solution and the mixing element is configured to mix the adsorbent with the aqueous solution. The mixing element may include a housing positioned on a distal end of a shaft. In some embodiments, the housing comprises a mesh material configured to contain the adsorbent within a reservoir while allowing the aqueous solution to contact the adsorbent. The housing may be positioned within a vessel of the adsorption unit and is configured to be submerged in the aqueous solution. In embodiments, the mixing element is configured to rotate the housing within the aqueous solution.

[0009] According to various embodiments, the rate limiting step of the system is the diffusion of the at least one metal or the at least one impurity metal through the adsorbent. Suitable adsorption rates of the at least one metal include at least about 0.1 mg / min / g, about 0.1 mg / min / g adsorbent to about 10 mg / min / g adsorbent, or any individual value or sub-range within these ranges.

[0010] Further disclosed herein according to one or more embodiments are methods of adsorbing a metal from a solution, comprising: contacting an aqueous solution containing at least one metal, at least one impurity metal, or combinations thereof with an adsorbent while mixing to adsorb the at least one metal or the at least one impurity metal. In one or more embodiments, the aqueous solution used in the methods comprises a brine, a metal product stream, a stream exiting a directmetal extraction process, a purified and concentrated brine, a stream existing a pond system, a feed stream to a metal recovery plant, water, sea water, brackish water, a raffinate stream, an impurity rich stream from a metal extraction process, an aqueous waste stream from a battery recycling process, or combinations thereof In one or more embodiments, the at least one metal comprises lithium, calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof. In at least one embodiment, the at least one metal is lithium, compounds thereof, salts thereof, or combinations thereof According to embodiments, the at least one impurity metal comprises calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof.

[0011] According to various embodiments, the at least one metal comprises lithium in an amount of less than about 1,200 ppm, about 0 ppm to about 1,200 ppm, about 5 ppm to about 1,000 ppm, about 20 ppm to about 750 ppm, about 100 ppm to about 500 ppm, or any individual value or subrange within these ranges. In some embodiments, the at least one metal comprises sodium in an amount of less than about 30,000 ppm, about 0 ppm to about 30,000 ppm, about 100 ppm to about 20,000 ppm, about 1,000 ppm to about 10,000 ppm, about 2,000 ppm to about 5,000 ppm, or any individual value or sub-range within these ranges, potassium in an amount of about 0 ppm to about 20,000 ppm, magnesium of about 0 ppm to about 4,000 ppm, calcium in an amount of about 2,000 ppm, boron in an amount of about 0 ppm to about 2,000 ppm, or combinations thereof. In one or more embodiments, the at least one impurity metal comprises sodium in an amount of about 0 ppm to about 30,000 ppm, potassium in an amount of about 0 ppm to about 20,000 ppm, magnesium of about 0 ppm to about 4,000 ppm, calcium in an amount of about 2,000 ppm, boron in an amount of about 0 ppm to about 2,000 ppm, or combinations thereof.

[0012] The adsorbent employed in the methods can be selective for the at least one metal or the at least one impurity metal. In some embodiments, the adsorbent is suitable to intercalate the at least one metal as compared to other metals at a ratio of 10: 1, optionally wherein the at least one metal comprises lithium, compounds thereof, salts thereof, or combinations thereof. In one or more embodiments, the adsorbent is in the form of sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, resin, pellets, particles coated with a chemical matrix, sheets, crystalline structures, or combinations of any two or more thereof. According to various embodiments, the adsorbent comprises a zwitterionic material, titanium-based material, manganese-based material, aluminum-based material, aluminum trihydroxide, boron trihydroxide, chromium trihydroxide, molybdenum trihydroxide, lanthanum trihydroxide, rhodium trihydroxide, thulium trihydroxide, zeolite molecular sieve, date pits impregnated with cellulose nanocrystals and ionic liquid, functionalized titanate nanotubes, polymeric porous microspheres with crown ether, granulated chitosan-lithium manganese oxide, manganese-based spinel compounds, modified activated carbon with multiple MnCh nanocomposite ratios, natural and / or synthetic zeolites applying poly(acrylic acid), MnO2-0.4H2O ion sieve, 1 D LiMr C nanorods, nano-lithium ion sieves, intercalated compositions thereof, a resin thereof, or combinations of any two or more thereof.

[0013] In one or more embodiments, methods as described herein can employ an adsorbent that is supported on a plurality of substrates. Optionally, the plurality of substrates include sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, or any combination thereof. According to embodiments, the plurality of substrates comprises carbon, a polymer, silica, alumina, or combinations of any two or more thereof.

[0014] In one or more embodiments, mixing in the methods is achieved using a mixing element comprising baffles, a paddle mixer, vortex mixer, impeller mixer, close clearance impeller mixer, helical ribbon impeller, double helical ribbon impeller, screw impeller, coil impeller mixer, propeller mixer, or combinations thereof. In some embodiments, the adsorbent and at least a portion of the mixing element are received within a vessel. In one or more embodiments the adsorbent is dispersed in the aqueous solution and the mixing element is configured to mix the adsorbent with the aqueous solution. The mixing element can include a housing positioned on a distal end of a shaft. The housing can include a mesh material configured to contain the adsorbent within a reservoir while mixing the aqueous solution to contact the adsorbent. In one or more embodiments, the housing is positioned within a vessel of an adsorption unit and is submerged in the aqueous solution. The mixing element is configured to rotate the housing within the aqueous solution.

[0015] According to various embodiments, the rate limiting step of the adsorption method is the diffusion of the at least one metal or at least one impurity metal through the adsorbent. In embodiments, the adsorption rate of the at least one metal is at least about 0.1 mg / min / g adsorbent to about 10 mg / min / g adsorbent.SUMMARY OF THE DRAWINGS

[0016] 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 (when used) indicate similar elements.

[0017] FIG. 1 is a representation of metal adsorption mechanisms in an aqueous solution containing a metal and in contact with an adsorbent according to various embodiments.

[0018] FIG. 2 is an embodiment of an adsorption system containing an adsorbent and a mixing element according to one or more embodiments herein.

[0019] FIG. 3 is an embodiment of an adsorption system containing an adsorbent and a mixing element according to one or more embodiments herein.Definitions

[0020] 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.

[0021] As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, reference to “an adsorption vessel” includes a single adsorption vessel as well as more than one adsorption vessel.

[0022] 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.

[0023] 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 themeasurement 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.”

[0024] 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.

[0025] 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).

[0026] 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.

[0027] Reference throughout this specification to a chemical element or a “metal” encompasses the basic chemical element or metal itself, ions, molecules containing the chemical element or metal, and / or ionic compounds containing the chemical element or metal, or combinations thereof. For example, “lithium” refers to the element lithium, lithium ions, lithium-containing molecules and lithium-containing ionic compounds, or combinations thereof.

[0028] The term “adsorption” as used herein encompasses chemisorption, physisorption and intercalation.

[0029] The term “intercalation” as used herein refers to the reversible insertion or adsorption of a chemical element or metal into the structure of the adsorbent material (e.g., a particulate matrix, a layered structure, a crystalline structure, etc.).DETAILED DESCRIPTION

[0030] 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.

[0031] Described herein are compositions, systems and methods for increasing the net transfer of one or more metals (e.g., lithium) from a solvent (e.g., a brine) onto an adsorbent. The various embodiments described herein explore the differences between the adsorption time needed for adsorption material pretreatment / wash, metal loading and elution using one or more columns as compared to the time needed in the absence of mass transfer limitations.

[0032] A representation 100 of adsorption mechanisms for an adsorbate 102 dissolved in a bulk aqueous solution 104 is shown in FIG. 1. The adsorption phenomenon of the adsorbate 102 (i.e., the at least one metal) that occurs in the bulk aqueous solution 104 is a bulk transport mechanism or bulk diffusion / convection 105 of the adsorbate 102 through the solution 104. When the adsorbate 102 enters the outer layer 106 nearer the adsorbent 108, it flows through the solution toward the adsorbent 108 via an external mass transfer mechanism 107.

[0033] When near the adsorbent 108 (e.g., an adsorbent particle), the adsorbate 102 behaves according to three different mechanisms: film diffusion 110, porous diffusion / surface diffusion 112, and adsorption 114. In the first mechanism, film diffusion 110, the adsorbate 102 diffuses through the outer film 110 surrounding the adsorbent 108. When the adsorbate 102 enters the pores 109 of the adsorbent’s 108 porous structure, it experiences a porous diffusion mechanism 112. During the porous diffusion mechanism, the adsorbate 102 is adsorbed into the interior of the adsorbent particle 108. When the adsorbate 102 gets close enough to the adsorbent 108 it adsorbs 114 or intercalates (i.e., typically by physisorption and / or intercalation, and / or by chemisorption) onto or within the adsorbent.

[0034] In conventional adsorbent tank systems, the rate limiting step for adsorption is when the adsorbate travels through the bulk solution 104. In such systems, the outer layer 106 is relatively thick and the amount of time it takes the adsorbate 102 to move through the outer layer 106 (i.e., by mass transfer 107) is dependent on the thickness of this layer. Film diffusion 110 is a slower process where the adsorbate travels through the outer film near the adsorbent 108 via the Weber- Morris model for pore diffusion. The porous diffusion or surface diffusion 112 of the adsorbate particle 102 through the adsorbent 108 also is a slow process that is diffusion rate dependent. Once the adsorbate particle 102 reaches the adsorbent 108 surface and adsorbs 114 onto active sites 111, this process is relatively fast. As such, speeding up one or more of these adsorption mechanisms can reduce the amount of time needed to adsorb one or more target metals onto the adsorbent.

[0035] Described herein are systems, compositions and methods that suitably mix the adsorbent 108 in the bulk solution 104 and outer layer 106 and / or increase the Reynolds number and / or turbulence of the aqueous solution to increase adsorption of adsorbate particles 102 (e.g., target metals such as lithium). This causes the adsorbate particles 102 to come into contact with theadsorbent 108 more quickly, which increases the adsorption mechanisms in these two phases 104, 106.

[0036] In some embodiments, the adsorbent 108 is a plurality of sub-units (e.g., a powder or particles) that is dissolved directly in the aqueous solution and a mixing element is utilized to mix the adsorbent 108 within the aqueous solution. The mixing forces may be suitable to cause the adsorbate particles 102 to contact the adsorbent 108 more quickly than when resting or slowly flowing through a conventional adsorption vessel. In some embodiments, the adsorbent is in the form of pellets and / or large sub-units that are contained within a mesh housing. The housing may be affixed to the end of a shaft of the mixing element such that both the housing and adsorbent contained therein are submerged within the aqueous solution. When the mixing element rotates the housing within the solution, the adsorbate particles 102 therein quickly move through the solution and come into contact with the adsorbent 108. Systems and methods as described herein significantly reduce or eliminate the rate limiting steps (i.e., bulk transport or bulk diffusion / convention 105, external mass transfer 107) in conventional adsorption systems and improve the efficiency of target metal (e.g., lithium) adsorption processes.

[0037] According to embodiments herein, external diffusion 105, 107 of the adsorbate 102 from the bulk aqueous solution 104, 106 is fast and the rate limiting step is the internal diffusion mechanism. Internal diffusion 110, 112, 114 within the adsorbent 108 is independent of agitation speed. Rather, internal diffusion 110, 112, 114 is governed by pore diffusion kinetics. To increase the adsorption kinetics near the adsorbent, the number of adsorption and / or intercalation sites may be increased by maximizing the exposed surface area of the adsorbent. This also may be accomplished by selecting a suitable adsorbent material.

[0038] For example, adsorption operations according to embodiments herein utilize materials that can selectively adsorb (i.e., by chemisorption, physisorption and / or intercalation) one or more metals. For example, a target metal may be dissolved in a solution containing several other metals. To preferentially adsorb the target metal, an adsorbent material is chosen and / or prepared to have stronger chemical interactions and / or physical bonds to the target metal as compared to the other non-target metals in the solution.

[0039] In various embodiments, the aqueous solution comprises a brine, a metal product stream, a stream exiting a direct metal extraction process, a purified and concentrated brine, a stream existing a pond system, a feed stream to a metal recovery plant, water, sea water, brackish water, a raffinate stream, an impurity rich stream from a metal extraction process, an aqueous waste stream from a battery recycling process, or combinations thereof. Each of these streams is likely to containing varying concentrations of lithium and varying combinations of lithium with other metals also at differing concentrations. According to one or more embodiments, the solution containing the metals includes, but is not limited to, a brine (e g., form a salar or lake), an aqueous waste stream from a lithium battery recycling process, and / or combinations thereof.

[0040] In some embodiments, the at least one metal comprises lithium, calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations of any two or more thereof. In various embodiments, the at least one impurity metal comprises calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations of any two or more thereof. It should be noted that, in one or more embodiments, the target metal is lithium, compounds thereof, salts thereof, or combinations thereof. Some adsorbent materials preferentially adsorb magnesium, calcium, compounds thereof, salts thereof, or combinations thereof (e.g., ions with two valence electrons) over lithium, compounds thereof, salts thereof, orcombinations thereof (e g., ions with one valence electron). In some embodiments, adsorption is used to preferentially remove magnesium, calcium, compounds thereof, salts thereof, or combinations thereof from the aqueous solution containing these metals along with lithium and other metals. The magnesium and calcium depleted solution may then flow into a second adsorption stage using either the same or a different adsorbent material to preferentially adsorb lithium, compounds thereof, salts thereof, or combinations thereof, over the other remaining metals in the solution. As such, in the first adsorption stage the magnesium and calcium are the target metals while the remaining metals are non-target (or impurity) metals for that stage. In the second adsorption stage, lithium is the target metal, and the remaining metals are non-target (or impurity) metals that are not adsorbed remain in the solution.

[0041] In one or more embodiments, the at least one metal comprises lithium in an amount of about 0 ppm to about 1,200 ppm, about 10 ppm to about 1,000 ppm, about 100 ppm to about 500 ppm, or any individual value or sub-range within these ranges. In some embodiments, the at least one metal comprises sodium in an amount of about 0 ppm to about 30,000 ppm, about 1,000 ppm to about 20,000 ppm, about 5,000 ppm to about 10,000 ppm, or any individual value or sub-range within these ranges. In some embodiments, the at least one metal comprises potassium in an amount of about 0 ppm to about 20,000 ppm, about 1,000 ppm to about 15,000 ppm, about 5,000 ppm to about 10,000 ppm, or any individual value or sub-range within these ranges. In some embodiments, the at least one metal comprises magnesium of about 0 ppm to about 4,000 ppm, about 100 ppm to about 3,000 ppm, about 1 ,000 ppm to about 2,000 ppm, or any individual value or sub-range within these ranges. In some embodiments, the at least one metal comprises calcium in an amount of about 0 ppm to about 2,000 ppm, about 100 ppm to about 1500 ppm, about 500 ppm to about 1,000 ppm, or any individual value or sub-range within these ranges. In someembodiments, the at least one metal comprises boron in an amount of about 0 ppm to about 2,000 ppm, about 100 ppm to about 1,500 ppm, about 500 ppm to about 1,000 ppm, or any individual value or sub-range within these ranges. In one or more embodiments, the at least one impurity metal comprises sodium in an amount of about 0 ppm to about 30,000 ppm, potassium in an amount of about 0 ppm to about 20,000 ppm, magnesium of about 0 ppm to about 4,000 ppm, calcium in an amount of about 2,000 ppm, boron in an amount of about 0 ppm to about 2,000 ppm, or combinations thereof.

[0042] In some embodiments, the solution feed to the adsorption system is a lithium-containing brine. In one or more embodiments, the solution contains lithium, sodium, potassium, magnesium, calcium, boron, a chloride thereof (e.g., lithium chloride, sodium chloride, etc ), a sulfate thereof (e g., lithium sulfate, potassium sulfate, etc.), and / or combinations thereof.

[0043] During an adsorption operation, the solution containing the at least one target metal together with the other metals flows through the adsorption unit coming into contact with the adsorbent material. When the adsorbent material is fresh, washed, regenerated and / or pre-treated, it has available adsorption sites at which the target metal can bind via chemisorption, physisorption and / or intercalation forces. As such, the at least one target metal transfers from the solution and adsorbs onto the adsorption material. This adsorption of the at least one target metal onto the adsorbent material is referred to herein as “loading.”

[0044] Disclosed herein according to various embodiments are systems for adsorbing a metal from a solution. Systems according to embodiments herein can include an inlet in fluid communication with an aqueous solution comprising at least one metal, at least one impurity metal, or combinations thereof. The inlet feeds an adsorption unit containing an adsorbent and a mixingelement. In various embodiments, the adsorbent is suitable to adsorb the at least one metal or the at least one impurity metal.

[0045] An exemplary adsorption system 200 is shown in FIG. 2. In various embodiments, the vessel may be a tank, open top drum, open top container, beaker, flask, a continuous flow vessel, or combination thereof. In this embodiment, an open top adsorption vessel 202 is configured to contain an aqueous solution in which an adsorbent is suspended 210. The open top of vessel 202 serves as the inlet 210 (and outlet) of the vessel. The aqueous solution may be introduced into inlet 210 of vessel 202 either before, together with, or after introducing the adsorbent. In some embodiments, when the aqueous solution is stagnant, the adsorbent forms soft agglomerates that are suspended in the aqueous solution, and / or the adsorbent settles at the bottom of the vessel, and / or the adsorbent floats on the upper surface of the aqueous solution.

[0046] In various embodiments, the adsorbent is selective for at least one metal or at least one impurity metal. According to embodiments, the adsorbent is suitable to intercalate the at least one metal as compared to other metals at a ratio of 10: 1. In one or more embodiments the adsorbent is in the form of sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, resin, pellets, particles coated with a chemical matrix, sheets, crystalline structures, a porous structure, or combinations of any two or more thereof.

[0047] Suitable adsorbents for use in the adsorption system include, but are not limited to, zwitterionic materials (e.g., urea-based compounds), titanium-based materials, manganese-based materials, aluminum-based materials, a resin thereof and / or combinations thereof. In one or more embodiments, the adsorbent comprises aluminum trihydroxide, boron trihydroxide, chromium trihydroxide, molybdenum trihydroxide, lanthanum trihydroxide, rhodium trihydroxide, thulium trihydroxide, zeolite molecular sieve, date pits impregnated with cellulose nanocrystals and ionicliquid, functionalized titanate nanotubes, polymeric porous microspheres with crown ether, granulated chitosan-lithium manganese oxide, manganese-based spinel compounds, modified activated carbon with multiple MnCh nanocomposite ratios, natural and / or synthetic zeolites applying poly(acrylic acid), MnO2-0.4H2O ion sieve, 1 D LiMmCh nanorods, nano-lithium ion sieves, intercalated compositions thereof, or combinations of any two or more thereof.

[0048] According to various embodiments, the adsorbent material is supported on a plurality of substrates. For example, the adsorbent material may be coated, sprayed, or otherwise deposited onto a plurality of substrates. The plurality of substrates may include sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, or any combination thereof. In embodiments, the plurality of substrates comprises carbon, a polymer, silica, alumina, or combinations of any two or more thereof.

[0049] The adsorbent may be dispersed within the aqueous solution using a mixing element. In one or more embodiments, the mixing element comprises baffles, a paddle mixer, vortex mixer, impeller mixer, close clearance impeller mixer, helical ribbon impeller, double helical ribbon impeller, screw impeller, coil impeller mixer, propeller mixer, or combinations thereof. Adsorption system 200 includes a mixing element having a shaft 204 with paddles 206 attached to a distal end of the shaft. In some embodiments, the adsorbent and at least a portion of the mixing element are received within the vessel 202. As shown in FIG. 2, the paddles are substantially submerged (e.g., at least partially or completely covered by the solution) within the aqueous solution containing the adsorbent 208. During operation, the mixing element rotates shaft 204 along with paddles 206, which are configured to sweep along the inside of vessel 202 (e.g., to sweep the inside wall of the vessel) to remove any adsorbent material that may adhere thereto. The mixing element causes the adsorbent (e.g., a plurality of units, a powder, particles, etc.) todisperse throughout, and / or suspend in the aqueous solution. The mixing rate increases the Reynold’s number of the solution causing laminar and, in some instances, turbulent flow. In some embodiments, suitable Reynold’s numbers may be at least about 2,300, or about 2,300 to about 10,000, or any individual value or sub-range within these ranges. These mixing forces are suitable to increase the interactions between the one or more adsorbate metals within the aqueous solution and the adsorbent. Dispersing the adsorbent throughout the aqueous solution also increases the exposed surface area of the adsorbent and, thus, the number of active sites on which the one or more adsorbate metals can adsorb.

[0050] When the adsorbent becomes fully loaded with the one or more adsorbate metals, the mixing element stops its operation. Subsequently, the adsorbent is separated (e.g., by fdtration, sieving, etc.) from the target metal depleted aqueous solution and then washed with a solvent (e.g., water) to recover the one or more adsorbed metals.

[0051] Another embodiment of an adsorption system 300 is shown in FIG. 3. In this embodiment, vessel 302 has an inlet (not shown) in the top and an outlet 312 at the bottom, which as shown, is stoppered. In this embodiment, a mixing element comprised of a shaft 304 has a housing 306 positioned at a distal end thereof. Housing 306 and at least a portion of shaft 304 are immersed in the aqueous solution 308. Housing 306 has a rigid, perforated structure extending out cylindrically about shaft 304. According to various embodiments, housing 306 is comprised of aluminum, stainless steel, copper, brass, bronze, titanium, gold, platinum, silver, alloys thereof, ceramic, or combinations thereof. As shown in FIG. 3, the perforations in housing 304 are circles. Other suitable shapes for the perforations may be used although circles provide even fluid mechanics. At least a portion of the interior reservoir (or cavity) of housing 304 contains a mesh material 307 that covers each of the perforations. According to various embodiments, the adsorbent material iscontained within the mesh material and prevented from exiting the housing into the aqueous solution 308. Maintaining the adsorbent within the housing prevents formation of a slurry within the bulk phase of the aqueous solution, which eliminates the need for a subsequent filtration step. Suitable mesh materials include, but are not limited to, stainless steel, carbon steel, plastics, perfluoroalkoxy fluoropolymer, polytetrafluoroethylene, polypropylene, or combinations thereof.

[0052] During operation, housing 304 and the adsorbent contained therein are rotated by shaft 304 within the aqueous solution 308. The mixing forces increase the Reynold’ s number of the solution, which causes the one or more target metal adsorbates to come into close contact with the adsorbent. This mixing substantially reduces the time for adsorption that is conventionally required for the adsorbates to move through the bulk phase and outer layer of the aqueous solution.

[0053] According to various embodiments, the rate limiting step of the systems according to embodiments herein is the diffusion of the at least one metal or the at least one impurity metal through the adsorbent. In embodiments, the adsorption rate of the at least one metal in the inventive systems is at least about 0.1 mg / min / g adsorbent, or about 0.1 mg / min / g adsorbent to about 10 mg / min / g adsorbent, or any individual value or sub-range within these ranges.

[0054] According to one or more embodiments, methods as described herein provide an adsorption rate of the at least one target metal onto the adsorption material of at least about 0.1 mg / min / g, at least about 0.2 mg / min / g adsorbent, at least about 0.5 mg / min / g adsorbent, at least about 1.0 mg / min / g adsorbent, at least about 5.0 mg / min / g adsorbent, at least about 10 mg / min / g adsorbent, about 0.1 mg / min / g adsorbent to about 10 mg / min / g adsorbent, or any individual value or subrange within these ranges. In some embodiments, when the target metal is lithium and the adsorption material is selective for lithium, the adsorption rate is at least about 0.1 mg / min / g adsorbent, at least about 0.2 mg / min / g adsorbent, at least about 0.5 mg / min / g adsorbent, at leastabout 1 .0 mg / min / g adsorbent, at least about 5.0 mg / min / g adsorbent, at least about 10 mg / min / g adsorbent, about 0.1 mg / min / g adsorbent to about 10 mg / min / g adsorbent, or any individual value or sub-range within these ranges.

[0055] When the adsorption material becomes loaded (e.g., more than about 90%, more than about 95%, more than about 99%, or any individual value or sub-range within these ranges, of the adsorption sites are occupied), the occupied adsorption sites are unable to bind with any target metal within the solution and the adsorption rate slows. It is then desirable to strip the target metal from the loaded adsorption material. This process may begin with optionally washing the loaded adsorption material to remove liquid and / or metals that are not adsorbed or intercalated with the adsorbent material. The washing process removes other non-target metals and liquids. Thus, the washed and loaded adsorbent material contains fewer impurities than the loaded adsorbent material prior to washing. In some embodiments, washing reduces impurities (i.e., non-target metals, undesired liquids, etc.) by at least about 0.1%, at least about 1%, at least about 5%, at least about 10%, or any individual value or sub-range within these ranges. Fluids suitable for washing the adsorbent material include, but are not limited to, water, deionized water, steam, carbon dioxide, and / or combinations thereof. In one or more embodiments, water is used to wash the loaded adsorption material.

[0056] During a stripping operation, the loaded adsorbent material (or the washed and loaded adsorption material) is contacted with an eluting agent during an elution operation to desorb the at least one target metal from the adsorbent. In one or more embodiments, the eluting agent is aqueous. Suitable eluting agents include, but are not limited to, water, deionized water, metal depleted return water, sodium hydroxide, hydrogen peroxide, ozone, hydrochloric acid, sulfuric acid, nitric acid, calcium chloride, and / or combinations thereof.

[0057] Without being bound by any particular theory, it is believed that the adsorption and desorption of the at least one target metal is dependent on the concentration of the target metal in the solution that reaches the void space on the surface of the adsorbent material. If the target metal exchanges with the adsorbent material in loading (i.e., binds to available adsorption sites) faster than the target metal in solution can reach the adsorption sites, then this is considered a mass transfer limited system. The kinetics of such a system can be determined where the target metal is loaded or stripped from the adsorbent material using a conventional adsorption column (e.g., a packed bed) where mass transfer limitations exist as compared to a freely mixed system (e.g., where the adsorbent material is mixed in the solution) where mass transfer limitations do not exist.

[0058] Once the kinetics of transfer without mass transfer limitations is known, the process of adsorption can be optimized to minimize such limitations and reduce the time of mixing as compared to the conventional column process. By increasing the rates at which the target metal is loaded and eluted (i.e., desorbed into an elution agent), the amount of adsorbent material needed is reduced by the ratio of the time saved. For example, if the loading and stripping time is reduced by a factor of 10, then the amount of adsorbent needed could be reduced by a factor of 10.

[0059] Once the target metal has been eluted from the adsorbent material, the spent adsorbent material may then be regenerated. In one or more embodiments, the spent adsorbent material may be contacted with a regeneration solvent to remove oil and impurities. Suitable solvents include, but are not limited to, polar solvents, non-polar solvents, acids or combinations thereof. Suitable polar solvents include, but are not limited to, water, metal depleted return water, deionized water, distilled water, acetone, isopropanol, ethanol, methanol, methylene chloride, ethyl acetate, and / or combinations thereof. Suitable non-polar solvents include, but are not limited to, hexane, heptane, methylcyclopentane, pentane, benzene, toluene, cyclohexane, and / or combinations thereof.During regeneration, the solvent may flow through the spent adsorbent material in forward or reverse flow.

[0060] The foregoing description discloses example embodiments of the disclosure. Modifications of the above-disclosed assemblies, apparatus, and methods which fall within the scope 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.

[0061] 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 necessarily 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 system for adsorbing a metal from a solution, comprising: an inlet in fluid communication with an aqueous solution comprising at least one metal, at least one impurity metal, or combinations thereof; and an adsorption unit comprising an adsorbent and a mixing element, wherein the adsorbent is suitable to adsorb the at least one metal or the at least one impurity metal.

2. The system of claim 1, wherein the aqueous solution comprises a brine, a metal product stream, a stream exiting a direct metal extraction process, a purified and concentrated brine, a stream existing a pond system, a feed stream to a metal recovery plant, water, sea water, brackish water, a raffinate stream, an impurity rich stream from a metal extraction process, an aqueous waste stream from a battery recycling process, or combinations thereof.

3. The system of claim 1, wherein the at least one metal comprises lithium, calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof.

4. The system of claim 1, wherein the at least one impurity metal comprises calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof.

5. The system of claim 1, wherein the adsorbent is selective for the at least one metal or the at least one impurity metal.

6. The system of claim 1 , wherein the adsorbent is suitable to intercalate the at least one metal as compared to other metals at a ratio of 10: 1, optionally wherein the at least one metal comprises lithium, compounds thereof, salts thereof, or combinations thereof.

7. The system of claim 1, wherein the adsorbent is in the form of sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, resin, pellets, particles coated with a chemical matrix, sheets, crystalline structures, or combinations of any two or more thereof.

8. The system of claim 1, wherein the adsorbent comprises aluminum trihydroxide, boron trihydroxide, chromium trihydroxide, molybdenum trihydroxide, lanthanum trihydroxide, rhodium trihydroxide, thulium trihydroxide, zeolite molecular sieve, date pits impregnated with cellulose nanocrystals and ionic liquid, functionalized titanate nanotubes, polymeric porous microspheres with crown ether, granulated chitosan-lithium manganese oxide, manganese-based spinel compounds, modified activated carbon with multiple MnCh nanocomposite ratios, natural and / or synthetic zeolites applying poly(acrylic acid), MnCh-O. fhO ion sieve, 1 D LiMn2O4 nanorods, nano-lithium ion sieves, intercalated compositions thereof, or combinations of any two or more thereof.

9. The system of claim 1, wherein the adsorbent is supported on a plurality of substrates, optionally, wherein the plurality of substrates comprises sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, or any combination thereof.

10. The system of claim 9, wherein the plurality of substrates comprises carbon, a polymer, silica, alumina, or combinations of any two or more thereof.

11. The system of claim 1, wherein the mixing element comprises baffles, a paddle mixer, vortex mixer, impeller mixer, close clearance impeller mixer, helical ribbon impeller, double helical ribbon impeller, screw impeller, coil impeller mixer, propeller mixer, or combinations thereof.

12. The system of claim 1, wherein the adsorbent and at least a portion of the mixing element are received within a vessel.

13. The system of claim 1, wherein the adsorbent is dispersed in the aqueous solution and the mixing element is configured to mix the adsorbent with the aqueous solution.

14. The system of claim 1, wherein the mixing element comprises a housing positioned on a distal end of a shaft.

15. The system of claim 14, wherein the housing comprises a mesh material configured to contain the adsorbent within a reservoir while allowing the aqueous solution to contact the adsorbent.

16. The system of claim 14, wherein the housing is positioned within a vessel of the adsorption unit and is configured to be submerged in the aqueous solution.

17. The system of claim 14, wherein the mixing element is configured to rotate the housing within the aqueous solution.

18. The system of claim 1, wherein the rate limiting step of the system is diffusion of the at least one metal or the at least one impurity metal through the adsorbent.

19. A method of adsorbing a metal from a solution, comprising: contacting an aqueous solution containing at least one metal, at least one impurity metal, or combinations thereof with an adsorbent while mixing to adsorb the at least one metal or the at least one impurity metal.

20. The method of claim 19, wherein the aqueous solution comprises a brine, a metal product stream, a stream exiting a direct metal extraction process, a purified and concentrated brine, a stream existing a pond system, a feed stream to a metal recovery plant, water, sea water, brackish water, a raffinate stream, an impurity rich stream from a metal extraction process, an aqueous waste stream from a battery recycling process, or combinations thereof.

21. The method of claim 19, wherein the at least one metal comprises lithium, calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof.

22. The method of claim 19, wherein the at least one impurity metal comprises calcium, magnesium, sodium, potassium, boron, compounds thereof, salts thereof, or combinations thereof.

23. The method of claim 19, wherein the adsorbent is selective for the at least one metal or the at least one impurity metal.

24. The method of claim 19, wherein the adsorbent is suitable to intercalate the at least one metal as compared to other metals at a ratio of 10: 1, optionally wherein the at least one metal comprises lithium, compounds thereof, salts thereof, or combinations thereof.

25. The method of claim 19, wherein the adsorbent is in the form of sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, resin, pellets, particles coated with a chemical matrix, sheets, crystalline structures, or combinations of any two or more thereof.

26. The method of claim 19, wherein the adsorbent comprises a zwitterionic material, titanium- based material, manganese-based material, aluminum-based material, aluminum trihydroxide, boron trihydroxide, chromium trihydroxide, molybdenum trihydroxide, lanthanum trihydroxide, rhodium trihydroxide, thulium trihydroxide, zeolite molecular sieve, date pits impregnated with cellulose nanocrystals and ionic liquid, functionalized titanate nanotubes, polymeric porous microspheres with crown ether, granulated chitosan-lithium manganese oxide, manganese-based spinel compounds, modified activated carbon with multiple MnCh nanocomposite ratios, natural and / or synthetic zeolites applying poly(acrylic acid), MnCh-O. fhO ion sieve, 1 D LiM C nanorods, nano-lithium ion sieves, intercalated compositions thereof, a resin thereof, or combinations of any two or more thereof.

27. The method of claim 19, wherein the adsorbent is supported on a plurality of substrates, optionally, wherein the plurality of substrates comprises sub-units, particles, granules, spheres, microspheres, extrudates, tablets, nanotubes, plates, or any combination thereof.- 21 -28. The method of claim 27, wherein the plurality of substrates comprises carbon, a polymer, silica, alumina, or combinations of any two or more thereof.

29. The method of claim 19, wherein mixing is by a mixing element comprising baffles, a paddle mixer, vortex mixer, impeller mixer, close clearance impeller mixer, helical ribbon impeller, double helical ribbon impeller, screw impeller, coil impeller mixer, propeller mixer, or combinations thereof.

30. The method of claim 29, wherein the adsorbent and at least a portion of the mixing element are received within a vessel.

31. The method of claim 29, wherein the adsorbent is dispersed in the aqueous solution and the mixing element is configured to mix the adsorbent with the aqueous solution.

32. The method of claim 29, wherein the mixing element comprises a housing positioned on a distal end of a shaft.

33. The method of claim 32, wherein the housing comprises a mesh material configured to contain the adsorbent within a reservoir while mixing the aqueous solution to contact the adsorbent.

34. The method of claim 32, wherein the housing is positioned within a vessel of an adsorption unit and is submerged in the aqueous solution.

35. The method of claim 32, wherein the mixing element is configured to rotate the housing within the aqueous solution.

36. The method of claim 19, wherein the rate limiting step of the adsorption is diffusion of the at least one metal or at least one impurity metal through the adsorbent.

37. The method of claim 19, wherein the at least one metal comprises lithium in an amount of 0 ppm to about 1,200 ppm, sodium in an amount of about 0 ppm to about 30,000 ppm, potassium in an amount of about 0 ppm to about 20,000 ppm, magnesium of about 0 ppm to about 4,000 ppm, calcium in an amount of about 2,000 ppm, boron in an amount of about 0 ppm to about 2,000 ppm, or combinations thereof.

38. The method of any claim 19, wherein the at least one impurity metal comprises sodium in an amount of about 0 ppm to about 30,000 ppm, potassium in an amount of about 0 ppm to about 20,000 ppm, magnesium of about 0 ppm to about 4,000 ppm, calcium in an amount of about 2,000 ppm, boron in an amount of about 0 ppm to about 2,000 ppm, or combinations thereof.

39. The method of claim 19, wherein the adsorption rate of the at least one metal is at least about 0.1 mg / min / g adsorbent to about 10 mg / min / g adsorbent.

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