Process and system for recovering lithium from lithium-ion batteries

Abstract

A system and method are provided for recovering lithium (Li) from a lithium-ion battery waste stream that includes lithium sulfate (Li2SO4), sodium sulfate (Na2SO4), and water (H2O). The system may include an evaporator unit with an optional heating system, and a crystallizer unit downstream or upstream of the evaporator unit for cooling and solidifying sodium sulfate (Na2SO4). A lithium recovery unit is located downstream of the crystallizer unit or the evaporator unit to produce a lithium carbonate (Li2CO3) product. The method includes evaporating a portion of the water from the waste stream to produce water vapor and an effluent stream. The effluent stream is then cooled and sodium sulfate (Na2SO4) is solidified in a crystallizer vessel. The solid sodium sulfate (Na2SO4) is removed and the effluent stream is heated, followed by the introduction of sodium carbonate (Na2CO3) to produce a lithium carbonate (Li2CO3) product, which is then recovered.

Description

Detailed Description of the Invention

[0001] [Technical field] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Application No. 63 / 332,025, filed April 18, 2022. The entire disclosure of the above application is incorporated herein by reference.

[0002] The present disclosure relates to systems and processes for recovering lithium (Li) as lithium carbonate (Li2CO3) product from lithium ion battery waste streams. [Background technology]

[0003] This section provides background art related to the present disclosure that is not necessarily prior art.

[0004] Electrochemical cells (e.g., rechargeable secondary lithium-ion batteries) are widely used as energy storage units in a variety of applications, including consumer products and vehicles. Lithium-ion batteries have a large energy density and battery voltage, a small shelf life and discharge rate, and a wide operating temperature range. However, the expected lifespan of such lithium-ion batteries is estimated to be approximately 3-10 years, after which the used batteries are discarded. It is important to recycle lithium-ion batteries (LIBs) because they often contain valuable metals (lithium, which can be wasted).

[0005] According to the United States Geological Survey, the lithium market is driven by demand from various industries, not only batteries but also ceramics, glass, lubricants, among others. Lithium is usually extracted from brines and ores, and the global crude lithium output is about 40,000 tonnes per year. However, the demand for lithium is increasing every year, which makes it necessary to recycle lithium and related components from lithium-ion batteries. Recycling lithium-ion batteries containing lithium will conserve the world's dwindling precious metal ores and also reduce the environmental challenges associated with e-waste processing.

[0006] During hydrometallurgy and refining processes, lithium is usually obtained in the form of lithium carbonate (Li2CO3). Lithium carbonate is used as a precursor to form the cathode / cathode materials in lithium-ion batteries, as well as to produce other compounds, such as lithium chloride (LiCl), lithium bromide (LiBr), and lithium oxide (Li2O). LiCl, LiBr, and Li2O can be raw materials for other industries. For example, LiBr can be used as an absorbent and refrigerant. Also, in the medical industry, lithium carbonate can be used as an active ingredient in the treatment of bipolar disorder. It is desirable to be able to recycle waste streams from lithium-ion batteries for the formation of beneficially reused products, including lithium carbonate (Li2CO3) products. Summary of the Invention

[0007] This section provides a general overview of the disclosure and is not an exhaustive disclosure of its entire scope or all of its constituent components.

[0008] In one embodiment, the disclosure relates to a system for recovering lithium from a lithium-ion battery waste stream. In one embodiment, the system includes an evaporator having an inlet, a first outlet, and a second outlet, and a crystallizer unit comprising: (i) at least one cooler; and (ii) a crystallizer vessel having an inlet, a first outlet, and a second outlet. In one variation, the inlet of the evaporator receives a liquid stream comprising lithium sulfate (Li2SO4), sodium sulfate (Na2SO4), and water (H2O). At least a portion of the water from the liquid stream is evaporated in the evaporator to produce water vapor passing through the second outlet and an effluent stream passing through the first outlet. The effluent stream is received by the crystallizer unit downstream of the evaporator and cooled to form solid sodium sulfate (Na2SO4). The inlet of the crystallizer vessel receives the effluent stream from the first outlet of the evaporator, removes the by-product including the solid sodium sulfate (Na2SO4) through the first outlet of the crystallizer vessel, and removes a second effluent stream through the second outlet of the crystallizer vessel. In an alternative variation, the liquid stream is received by the crystallizer unit and cooled to form solid sodium sulfate (Na2SO4). The inlet of the crystallizer vessel receives the liquid stream, removes the by-product including the solid sodium sulfate (Na2SO4) through the first outlet of the crystallizer vessel, and removes a third effluent stream through the second outlet of the crystallizer vessel. The inlet of the evaporator receives the third effluent stream including lithium sulfate (Li2SO4) and water (H2O), and at least a portion of the water from the third effluent stream is evaporated in the evaporator to produce water vapor through the second outlet and a fourth effluent stream through the first outlet. The system further comprises a lithium recovery unit downstream of the crystallizer unit or the evaporator.The lithium recovery unit comprises: (i) a reactor having a first inlet for receiving the second effluent stream from the crystallizer unit or the fourth effluent stream from the evaporator, a second inlet for receiving sodium carbonate (Na2CO3), an outlet, and an agitator, (ii) a heat source in thermal communication with the reactor, and (iii) a solid-liquid separator in fluid communication with the outlet of the reactor, the solid-liquid separator passing a product stream through the solid-liquid separator to separate the product into a retentate comprising lithium carbonate (Li2CO3) product and a waste stream. The system further comprises fluid conduits for establishing fluid communication between the evaporator, the crystallizer unit, and the lithium recovery unit, and at least one pump for circulating fluid within the fluid conduits.

[0009] In one embodiment, the system further comprises a heating system upstream of the evaporator, the heating system comprising at least one heater for heating the liquid stream prior to entering the evaporator.

[0010] In a further aspect, the heater is a preheater and the heating system further comprises a heat exchanger downstream of the preheater, the heat exchanger receiving water vapor from the evaporator and the liquid stream in heat exchange relationship to increase a temperature of the liquid stream.

[0011] In a further aspect, the heating system further comprises a compressor disposed between the evaporator and the heat exchanger, the compressor increasing at least one of the pressure and temperature of the water vapor prior to entering the heat exchanger.

[0012] In a further aspect, at least one of the coolers includes a heat exchanger receiving the liquid stream and the third effluent stream in heat exchange relationship to reduce a temperature of the liquid stream and to increase a temperature of the third effluent prior to entering the evaporator.

[0013] In one aspect, the crystallizer unit further comprises a plurality of coolers upstream of the crystallizer vessel.

[0014] In a further aspect, at least one of the plurality of coolers receives a stream from the crystallizer vessel and the liquid stream in a heat exchange relationship with one another and reduces a temperature of the liquid stream.

[0015] In one embodiment, the crystallizer unit further comprises a centrifuge downstream of the first outlet of the crystallizer vessel, the centrifuge receiving the by-product comprising the solid sodium sulfate (Na2SO4) and separating liquid from the sodium sulfate (Na2SO4) solids.

[0016] In a further aspect, the crystallizer unit further comprises a plurality of coolers upstream of the crystallizer vessel, at least one of the plurality of coolers receiving liquid from the centrifuge in heat exchange relationship with the liquid stream to reduce a temperature of the liquid stream.

[0017] In one embodiment, the solid-liquid separator is selected from the group consisting of a pneumatic filter and a centrifuge.

[0018] In another aspect, the disclosure relates to a process for recovering lithium from a lithium-ion battery waste stream. In one aspect, the process includes solidifying sodium sulfate (Na2SO4) from a liquid stream containing lithium sulfate (Li2SO4), sodium sulfate (Na2SO4), and water (H2O). In one variation, the solidifying sodium sulfate (Na2SO4) includes evaporating a portion of the water in the liquid stream containing lithium sulfate (Li2SO4), sodium sulfate (Na2SO4), and water (H2O) to produce water vapor and an effluent stream. The process further includes cooling the effluent stream to solidify sodium sulfate (Na2SO4) from the effluent stream in a crystallizer vessel to produce a second effluent stream. In an alternative variation, solidifying sodium sulfate (Na2SO4) includes cooling the liquid stream to solidify sodium sulfate (Na2SO4) from the liquid stream in a crystallizer vessel to produce a third effluent stream, and evaporating a portion of the water in the third effluent stream to produce water vapor and a fourth effluent stream. The process then includes removing the sodium sulfate (Na2SO4) solids from the second or third effluent stream, followed by heating the second or fourth effluent stream to introduce sodium carbonate (Na2CO3) into the second or fourth effluent stream to produce a lithium carbonate (Li2CO3) product stream. Finally, the process includes separating lithium carbonate (Li2CO3) from the lithium carbonate (Li2CO3) product stream.

[0019] In one aspect, the process further comprises: Part of the water in Evaporate than prior to the step of heating the liquid stream to a temperature of about 90° C. or greater.

[0020] In one embodiment, the process further comprises: Part of the water in Evaporate than prior to the step of heating the third effluent stream to a temperature of about 90° C. or greater.

[0021] In a further aspect, the step of heating the liquid stream further comprises exchanging heat with the water vapor produced during evaporation.

[0022] In a further embodiment, the step of heating the third effluent stream further comprises exchanging heat with the liquid stream.

[0023] In a further aspect, the process further comprises compressing the water vapor prior to exchanging heat with the liquid stream.

[0024] In one embodiment, the step of heating the second effluent stream or the fourth effluent stream is a step of heating the second effluent stream or the fourth effluent stream to a temperature of at least about 80° C. and less than about 100° C., and the process includes maintaining the temperature during the step of introducing sodium carbonate (Na2CO3).

[0025] In one embodiment, the step of introducing sodium carbonate (Na2CO3) is a step of introducing sodium carbonate (Na2CO3) in a stoichiometric excess of about 10% to about 15%.

[0026] In one embodiment, the step of cooling the effluent stream or the liquid stream comprises cooling the effluent stream or the liquid stream to a temperature of about 0° C. or less.

[0027] In a further embodiment, the step of cooling is performed in multiple cooling stages. In a first cooling stage, the temperature of the effluent or liquid stream is reduced to a temperature of about 40° C. or less. In a second cooling stage, the temperature of the effluent or liquid stream is reduced to a temperature of about 30° C. or less. In a third cooling stage, the temperature of the effluent or liquid stream is reduced to a temperature of about −2° C. or less.

[0028] In one embodiment, the step of cooling the liquid stream comprises exchanging heat with the third effluent produced in the crystallizer vessel.

[0029] In one embodiment, the step of removing the sodium sulfate (Na2SO4) solids from the second effluent stream or the third effluent stream is performed by centrifuging a by-product stream containing the sodium sulfate (Na2SO4) solids to separate liquids and collect the sodium sulfate (Na2SO4) solids.

[0030] In one embodiment, the lithium carbonate (Li2CO3) product has a purity of about 80% by weight or greater.

[0031] In a further embodiment, a portion of the fourth effluent stream is combined with the liquid stream.

[0032] Further scope of applicability will become apparent from the description provided herein. The description and specific examples in this summary are for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are intended only to illustrate selected embodiments and not all possible embodiments, and are not intended to limit the scope of the present disclosure.

[0034] FIG. 1 shows a system for recovering lithium from waste streams derived from lithium-ion batteries according to one variation of the present disclosure.

[0035] FIG. 2 shows a partial view of a system for recovering lithium according to an alternative variation of the present disclosure, including a heater system upstream of the evaporation system.

[0036] FIG. 3 shows a partial view of a system for recovering lithium according to an alternative variation of the present disclosure, including a multi-stage cooler system upstream of the crystallizer vessel within the crystallization unit.

[0037] FIG. 4 shows an example of a process for recovering lithium according to certain variations of the present disclosure.

[0038] FIG. 5 shows an alternative system for recovering lithium from waste streams derived from lithium-ion batteries according to a variation of the present disclosure, which includes a crystallization unit upstream of the evaporator.

[0039] FIG. 6 shows an alternative system for recovering lithium from waste streams derived from lithium-ion batteries according to a variation of the present disclosure, which includes a crystallization unit upstream of the evaporator and further includes a reflux stream in the system.

[0040] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. Detailed Description

[0041] The exemplary embodiments are provided so that the disclosure will be thorough and the scope will be fully conveyed to those skilled in the art. Numerous specific details are described, such as examples of specific compositions, components, devices and methods, so as to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that the exemplary embodiments can be implemented in many different forms, and that none of these should be construed to limit the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0042] The terms used herein are for the purpose of describing particular exemplary embodiments only and are not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural unless otherwise specified. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, elements, compositions, steps, integers, operations, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The open-ended term "comprising" should be construed as a non-limiting term used to describe and claim the various embodiments described herein, although in certain aspects, the term may alternatively be construed as a rather more restrictive and restrictive term, such as "consisting of" or "consisting essentially of." Thus, for any given embodiment reciting compositions, materials, components, elements, features, integers, operations, and / or process steps, the disclosure specifically includes embodiments that consist of or consist essentially of the recited compositions, materials, components, elements, features, integers, operations, and / or process steps, etc. In the case of "consisting of," the alternative embodiment excludes any additional compositions, materials, components, elements, features, integers, operations, and / or process steps that materially affect the basic and novel properties, while in the case of "consisting essentially of," any additional compositions, materials, components, elements, features, integers, operations, and / or process steps that do not materially affect the basic and novel properties may be included in the embodiment.

[0043] Any method steps, processes, and operations described herein should not be construed as necessarily requiring them to be performed in the particular order described or illustrated, unless specifically identified as to the order of execution, and it should be understood that additional or alternative steps may be employed, unless otherwise indicated.

[0044] When a component, element, or layer is referred to as being "on," "engaged to," "connected to," or "coupled to" another element or layer, the component, element, or layer may be directly on, engaged, connected, or coupled to the other component, element, or layer, or there may be intervening elements or layers present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there may not be intervening elements or layers present. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] Terms such as first, second, third, etc. may be used herein to describe various steps, elements, components, regions, layers, and / or sections, but these steps, elements, components, regions, layers, and / or sections should not be limited by these terms unless otherwise specified. These terms may only be used to distinguish one step, element, component, region, layer, or section from another step, element, component, region, layer, or section. Terms such as "first", "second", etc., as used herein, and other number terms, do not imply any sequence or order unless otherwise specified. Thus, a first step, element, component, region, layer, or section described below can also be referred to as a second step, element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0046] Spatial or temporal relative terms such as "front," "rear," "inside," "outside," "below," "lower," "upper," "above," and the like may be used herein to describe and facilitate the description of an element or feature in relation to another element or feature(s) illustrated in the figures. Spatial or temporal relative terms may be intended to encompass various orientations of a device or system in use or operation in addition to the orientation depicted in the figures.

[0047] Throughout this disclosure, numerical values ​​represent approximate measurements or limits to ranges that encompass slight deviations from a given value, embodiments with approximately the stated value, and embodiments with the exact stated value. Other than the examples provided at the end of the detailed description, all numerical values ​​of parameters (e.g., parameters of quantities or conditions) in this specification, including the appended claims, should be understood to be modified in all cases by the term "about", regardless of whether "about" actually appears before the numerical value. "About" indicates that the numerical value described allows for some slight imprecision (somewhat close to the exact value; approximately or reasonably close to the value; in the vicinity). When the imprecision introduced by "about" is not otherwise understood in this ordinary sense in the art, "about" as used herein indicates the minimum variation that may occur from the ordinary method of measuring and using such parameters. For example, "about" can include a variation of 5% or less, optionally a variation of 4% or less, optionally a variation of 3% or less, optionally a variation of 2% or less, optionally a variation of 1% or less, optionally a variation of 0.5% or less, and in some embodiments, optionally a variation of 0.1% or less.

[0048] In addition, the disclosure of a range includes the disclosure of all values ​​and further divided ranges within the entire range, including the endpoints and subranges given for the range. Thus, unless otherwise specified, the range includes the endpoints and also includes the disclosure of all separate values ​​and further divided ranges within the entire range. The disclosure of values ​​and ranges of values ​​for a particular parameter (e.g., temperature, molecular weight, weight percent) does not exclude other values ​​and ranges of values ​​useful herein. It is contemplated that two or more specific exemplified values ​​for a given parameter may define endpoints for the range of values ​​that may be claimed for that parameter. For example, in this specification, if parameter X is exemplified as having a value A, and further, parameter X is exemplified as having a value Z, it is contemplated that parameter X may have a range of values ​​from about A to about Z. Similarly, the disclosure of two or more ranges of values ​​for a parameter (whether such ranges are nested, overlapping, or separate) is contemplated to encompass all possible combinations of the ranges of values ​​that may be claimed using the endpoints of the disclosed ranges. For example, if a parameter X is exemplified herein as having a value in the range of 1 to 10, or 2 to 9, or 3 to 8, it is contemplated that the parameter X can have other ranges of values ​​including 1 to 9, 1 to 8, 1 to 3, 1 to 2, 2 to 10, 2 to 8, 2 to 3, 3 to 10, and 3 to 9.

[0049] Unless otherwise stated, composition amounts are by weight. Additionally, when an amount is expressed as weight, it should be understood to reflect the mass of a given component, although it may be used interchangeably with mass.

[0050] As used herein, the terms "composition" and "material" are used interchangeably to refer broadly to a substance that contains at least a preferred chemical component, element, or compound, and may also contain additional elements, compounds, or substances, including trace amounts of impurities, unless otherwise indicated.

[0051] In the diagrams, the direction of the arrows, indicated by arrowheads, generally indicates the flow of material or information (e.g., data or instructions) involved in the illustration. For example, an arrow may be directed from element A to element B, where element A and element B are exchanging various information, but the information sent from element A to element B is relevant to the illustration. This unidirectional arrow does not imply that other information is not sent from element B to element A. Additionally, for information sent from element A to element B, element B may send a request for the information or an acknowledgment of receipt to element A.

[0052] In this application, including in the following description, the term "module" or "controller" may be interchanged with the term "circuitry" when used in the context of, for example, a computing device or computing module. The terms "module" and / or "controller" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinatorial logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, for example in a system on chip.

[0053] The modules and / or controllers may include one or more interface circuits. In some embodiments, the interface circuits may include wired or wireless interfaces that connect to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module and / or controller of the present disclosure may be distributed among multiple modules and / or controllers that are connected via interface circuits. For example, multiple modules and / or controllers may enable load balancing. In further embodiments, a server (also known as remote, or cloud) module and / or server controller may perform some functionality on behalf of a client module and / or client controller.

[0054] The term code as used above may include software, firmware, and / or microcode and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all of the code from multiple modules and / or controllers. The term group processor circuit encompasses a processor circuit that executes some or all of the code from one or more modules and / or controllers in combination with additional processor circuits. References to multiple processor circuits encompass multiple processor circuits on a discrete die, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or combinations of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all of the code from multiple modules and / or controllers. The term group memory circuit encompasses a memory circuit that stores some or all of the code from one or more modules and / or controllers in combination with additional memory.

[0055] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium as used herein does not include a transitory electric or electromagnetic signal that propagates through a medium (e.g., on a carrier wave); therefore, the term computer-readable medium can be considered to be tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media include non-volatile memory circuits (e.g., flash memory circuits, erasable programmable read-only memory circuits, or masked read-only memory circuits, etc.), volatile memory circuits (e.g., static random access memory circuits or dynamic random access memory circuits, etc.), magnetic storage media (e.g., analog or digital magnetic tape, or hard disk drive, etc.), and optical storage media (e.g., CD, DVD, or Blu-ray disk, etc.).

[0056] The apparatus and methods described in this application may be implemented partially or completely by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The functional blocks, flow chart components, and other elements described above function as software specifications, which can be converted into a computer program by the routine work of a skilled technician or programmer.

[0057] A computer program includes processor-executable instructions stored on at least one non-transitory, tangible computer-readable medium. A computer program may also include or depend on stored data. A computer program may include a basic input / output system (BIOS) that interacts with the hardware of a special-purpose computer, device drivers that interact with specific devices of a special-purpose computer, one or more operating systems, user applications, background services, background applications, and the like.

[0058] A computer program may include (i) text that is parsed, such as hypertext markup language (HTML), extensible markup language (XML), or JavaScript Object Notation (JSON); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code that is executed by an interpreter; or (v) source code that is compiled and executed by a just-in-time compiler. By way of example only, the source code may be written using syntax in languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java, Fortran, Perl, Pascal, Curl, OCaml, Javascript, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash, Visual Basic, Lua, MATLAB, SIMULINK, and Python.

[0059] None of the elements recited in the claims are intended to be means-plus-function elements within the meaning of 35 U.S.C. 112(f) unless an element is expressly recited using the phrase "means for" or, except in the case of a method claim, using the phrase "act for" or "step for."

[0060] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0061] In various embodiments, the disclosure contemplates forming one or more recycled products from a lithium-ion battery waste stream, where at least one of the recycled products includes lithium (Li). In one variation, the lithium (Li)-containing recycled product may include lithium carbonate (Li2CO3). The disclosure also contemplates forming sodium sulfate (Na2SO4) as a beneficially reused by-product in one variation. Additionally, the disclosure contemplates a system for recovering recycled lithium-containing products from a lithium-ion battery waste stream.

[0062] Lithium-ion battery waste streams are formed from lithium-ion batteries after they have been disassembled, crushed, and / or shredded. Such waste streams may be a material known as black mass that is intended to be recycled. Collectively, black mass may include portions of one or more used lithium-ion batteries, including portions from lithium-ion batteries of different types (e.g., having different active materials). Black mass typically includes all active materials. Thus, black mass may include anode active materials and electrolyte components mixed with cathode active materials. In some embodiments, the spent lithium ion batteries may include positive electrodes / cathodes made from lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium nickel manganese cobalt oxides (NMC), lithium iron phosphate (LFP), lithium nickel cobalt aluminum oxide (NCA), lithium titanate (LTO), etc. See, for example, Table 1, which lists active material combinations for common commercially available batteries. The spent lithium ion batteries may include negative electrodes / anodes made from graphite, lithium titanate oxide (Li2TiO3-LTO), lithium metal, etc.

[0063] [Table 1]

[0064] Additionally, the black mass may include electrolyte components including lithium salts, which may include fluorine, such as lithium hexafluorophosphate (LiPF6). As a result, the black mass may include metals of interest (e.g., precious metals) to be recovered, such as lithium (Li), nickel (Ni), manganese (Mn), cobalt (Co), and impurities, such as iron (Fe), copper (Cu), fluorine (F), phosphorus (P), titanium (Ti), aluminum (Al), and the like. It is understood that the black mass composition may vary from batch to batch depending on the type of lithium ion battery.

[0065] In various embodiments, the systems and processes disclosed herein can recycle spent lithium-ion batteries to recover and separate lithium from other components / impurities contained in the black mass and recover lithium-containing species. As an example, the methods and systems provided by the present disclosure can process lithium-ion battery waste streams to separate and recover lithium (Li) from various other elements, including fluorine (F), phosphorus (P), copper (Cu), aluminum (Al), iron (Fe), carbon (C) (e.g., in the form of graphite), titanium (Ti), nickel (Ni), manganese (Mn), cobalt (Co), and combinations thereof. In some embodiments, lithium is extracted from spent lithium-ion batteries (LIBs) by leaching to form lithium sulfate (Li2SO4), which is then reacted to recover lithium as lithium carbonate (Li2CO3).

[0066] In some embodiments, one or more separation and / or purification processes may be implemented as upstream steps of the present systems and processes for recovering lithium, such that a waste stream derived from the lithium ion battery waste stream is formed. Thus, the waste stream may be a liquid stream that includes lithium (Li) (e.g., includes one or more lithium-containing compounds). In some variations, the liquid stream derived from the lithium ion battery waste stream includes lithium sulfate (Li2SO4), sodium sulfate (Na2SO4), and water (H2O). As a non-limiting example, "PROCESSES AND SYSTEMS FOR PURIFYING HYDROGEN SULFATE" filed on February 22, 2023, is incorporated herein by reference. AND RECYCLING LITHIUM-ION BATTERY WASTE Such waste streams may be formed in the processes and systems described in commonly owned U.S. Patent Application No. 18 / 112,676 entitled "PROCESS FOR REMOVING IMPURITIES IN THE RECYCLING OF LITHIUM-ION BATTERIES," PCT Application No. PCT / SG2021 / 050496, published as WO2022 / 045973 on March 3, 2022, entitled "PROCESS FOR REMOVING IMPURITIES IN THE RECYCLING OF LITHIUM-ION BATTERIES," and PCT Application No. PCT / SG2022 / 050014, filed on January 17, 2022, the relevant portions of each of which are incorporated herein by reference. Various processes may include using sodium hydroxide (NaOH) as an alkaline base to alter the pH to achieve precipitation of valuable metals during various hydrometallurgical processes in the recycling of waste streams from lithium ion batteries. In certain such processes described above, sulfates of various metals, such as nickel sulfate, manganese sulfate, and cobalt sulfate, may be mixed and dissolved with sodium sulfate and lithium sulfate. The nickel, manganese, and cobalt sulfates may be separated (precipitated) or otherwise recovered (e.g., as a precipitate product) upstream from the lithium sulfate and sodium sulfate. The present technology relates to improved methods and systems for recovering and purifying lithium-containing compounds from sodium-containing compounds (e.g., separating lithium sulfate from sodium sulfate).

[0067] Generally, the initial concentration of lithium in the solution of the liquid stream is too low to effectively recycle lithium. Furthermore, there are particular challenges in achieving effective separation of lithium (Li) and sodium (Na) from each other, since both are group I elements of the IUPAC periodic table. For example, sodium and lithium have high solubility in many liquid media. Compounding the difficulty of lithium recovery is that the solubility products of both sodium and lithium salts are very close, resulting in co-solidification of sodium and lithium in many solvent systems. In certain embodiments, the technology contemplates recovering significant amounts of lithium from liquid waste streams. For example, in the methods and systems contemplated herein, significant amounts of lithium sulfate (Li2SO4) are extracted from a liquid stream containing sodium sulfate (Na2SO4) and water.

[0068] In certain embodiments where the lithium ion battery waste stream initially contains lithium (Li), the lithium may be removed with a separation efficiency of about 75% or greater, or any of the values ​​specified below. The separation efficiency may be calculated by comparing the initial amount of lithium present in the stream prior to treatment to the final amount of lithium present in the product after treatment or separation. In certain embodiments, the separation efficiency (η) for a given component, such as lithium, may be expressed by the following equation:

[0069]

number

[0070] where x i is the initial amount of lithium (either by mass or volume), and x fis the final amount of lithium after the separation process is completed. As described in more detail below, in certain variations, the efficiency of separation using the systems and methods of the present invention for recovering lithium may be about 75% or more, optionally about 80% or more, optionally about 85% or more, optionally about 90% or more, optionally about 95% or more, optionally about 96% or more, optionally about 97% or more, optionally about 98% or more, and in some variations, optionally about 99% or more, in terms of lithium.

[0071] In general, the present disclosure contemplates an economical method and system / plant for recovering lithium-containing products (e.g., lithium carbonate (Li2CO3)) from lithium-ion battery waste streams by providing a water recovery process to concentrate the lithium species present, producing and recovering lithium carbonate (Li2CO3) as a product, and optionally producing sodium sulfate (Na2SO4) as a by-product. The lithium carbonate (Li2CO3) can be economically reused in various industries (e.g., but not limited to, the lithium battery industry, the concrete industry, ceramics, clinker and tile manufacturing, etc.).

[0072] Generally, the present disclosure provides both a system and a process for concentrating lithium-containing species in a liquid stream to facilitate the recovery of lithium. In a variation, the process of concentrating lithium-containing species is carried out in an energy efficient manner. In one variation, water may be separated from a heated liquid waste stream (e.g., including lithium sulfate, sodium sulfate, and water) derived from lithium-ion battery waste.

[0073] In one variation, the present disclosure contemplates a process for recovering lithium from a lithium-ion battery waste stream, the process including solidifying sodium sulfate (NaSO) from a liquid stream containing lithium sulfate (LiSO), sodium sulfate (NaSO), and water (HO).

[0074] In any embodiment, solidifying sodium sulfate (Na2SO4) from the liquid stream includes separating a portion of the water from the liquid stream containing lithium sulfate (Li2SO4), sodium sulfate (Na2SO4), and water (H2O). Separating a portion of the water may include vaporizing or evaporating a portion of the water in the liquid stream to produce water vapor and a concentrated liquid stream or effluent stream. In one variation, the amount of water removed during separation / evaporation (comparing the initial concentration of water in the waste stream to the final concentration after vaporization) may be about 70% to about 90% by weight. After the separation step, the concentration of lithium sulfate (Li2SO4) in the effluent stream may be about 8 g / L to about 14 g / L, and the concentration of sodium sulfate (Na2SO4) in the effluent stream may be about 50 g / L to about 100 g / L. At this time, about 10% to about 20% by weight of the initial amount of water remains in the effluent stream.

[0075] In one variation, the separation occurs in an evaporator where at least a portion of the water is evaporated from the liquid stream to produce a concentrated liquid stream and water vapor or steam. There may be a single evaporator or multiple evaporators or condensers in a parallel or series configuration.

[0076] In any embodiment, the liquid stream may be heated prior to the evaporating step, for example, by passing the liquid stream through one or more heaters (e.g., preheaters). In some embodiments, one or more preheaters or heat exchangers may be used to heat the liquid stream prior to entering the evaporator. For example, the method may include a step of heating the liquid, for example to a temperature of about 90° C. or higher, prior to evaporating the water. In some embodiments, the effluent stream (heated liquid stream) has a temperature after the heating step such that the Na2SO4 concentration is near saturation levels.

[0077] The heater may be a heat exchanger that circulates a heat exchange medium or fluid (e.g., water vapor / steam or air, etc.) or may have a heating element (e.g., an electrical heating element, a fuel-based heating element) to heat the incoming liquid stream to a predetermined temperature before entering the evaporator. The heat exchanger may include a finned-tube heat exchanger, a brazed plate heat exchanger, a plate-and-frame heat exchanger, a concentric heat exchanger, a microchannel heat exchanger, or other heat exchanger. The liquid stream may proceed in a first direction and the heat exchange medium in the second stream may proceed in a second direction. The second direction may be in a co-current, counter-current, or cross-current relationship to the first direction.

[0078] In one embodiment, the process is a continuous process and the water vapor / steam generated during the downstream evaporation step may be recycled or circulated through a heat exchanger device to exchange heat with the liquid stream. In one variation, the process may further include compressing the water vapor after it leaves the evaporator by treating the water vapor in a compressor prior to exchanging heat with the liquid stream.

[0079] In this variation, the liquid may be preheated by a preheater and the heating source may be, at least in part, secondary steam condensate of the system generated in the evaporator. After the preheating step, the liquid stream enters the evaporation system. Due to the complexity of the materials involved in the liquid stream, in order to avoid shutdowns that may be caused by scaling and to increase the stability of the system, in some embodiments the feed flow may be automatically adjusted to maintain the liquid level in the separator / evaporator. As one skilled in the art would understand, the feed flow will depend on the size or scale of the evaporation system.

[0080] In some variations, the evaporation system employs a forced circulation process and is provided with an optional forced circulation pump. The forced circulation pump may be in the form of a compressor or other pump to ensure a high flow rate of material in the heat exchanger (e.g., in its tubes) and to prevent the material in the liquid stream from scaling and blocking the internal flow conduits (e.g., tubes). In some variations, the optional forced circulation pump may increase the pressure of the stream being treated to about 0.2 MPa or more and about 0.25 MPa or less. In some embodiments, the forced circulation process for the evaporation system provided by some embodiments of the present disclosure provides one or more of the following advantages: (1) a forced circulation evaporator may be used to avoid boiling on the heat transfer surface, which may cause fouling or the formation of crystallization; (2) the circulation of the evaporation liquid in the device is mainly due to the forced flow of the circulation pump; (3) the material in the liquid stream does not evaporate in the heater and does not change concentration in the heat exchanger. Alternatively, any separation device such as a crystallizer (crystallizer vessel, centrifuge, etc.) may be used. or in any of these devices After flushing in To,The concentration of the material increases. Therefore, the material does not adhere to the heat exchange surface and does not cause fouling on the heat exchange surface; (4) the body of the separation crystallizer has a sufficient liquid / gas separation area and separation height, which can ensure long-term evaporation and stable discharge concentration. In one variant, the separation crystallizer may include a vessel having an internal dimension (Φ) of about 1,000 mm (1 m) x about 2,000 mm (2 m).

[0081] In certain embodiments where a heat exchanger is provided to facilitate the heat exchange from the water vapor / steam generated in the evaporator to the liquid stream, the method provides certain advantages. For example, in certain embodiments, an advantage of the disclosed system and method having a heating system is that only a small amount of feed steam is required to make up for heat losses during normal / steady state operation of the system, and some feed steam may be required for start-up. As shown in FIG. 2, the secondary steam generated by the evaporation of the liquid stream enters the vapor compressor and returns to the main heat exchanger after the compressor has worked to increase the temperature and pressure as an energy source for material evaporation.

[0082] Furthermore, after the secondary steam from the evaporator heats the liquid flow material, the water vapor / steam condenses into liquid water, which may be collected in a condensate tank (not shown). The condensate may then be pumped to a condensate preheater so that the feed liquid is preheated. The cooled condensate may then be discharged from the system.

[0083] In a further embodiment, not shown, the non-condensable gases produced by the system are cooled by a non-condensable condenser (in the form of a heat exchanger) and the condensate enters a condensate water tank, after which the non-condensable gases are collected and may be further treated, for example with activated carbon, before being discharged.

[0084] The method further includes cooling the effluent stream after removing a portion of the water from the liquid stream in an evaporative portion of the system such that lithium sulfate (LiSO) and sodium sulfate (NaSO) are concentrated in the liquid stream, and solidifying sodium sulfate (NaSO) solids from the effluent stream in a crystallizer vessel.

[0085] In certain embodiments, the effluent stream is cooled to a temperature of about 20° C. or less, optionally cooled to a temperature of about 10° C. or less, optionally cooled to a temperature of about 5° C. or less, optionally cooled to a temperature of about 3° C. or less, optionally cooled to a temperature of about 0° C. or less, optionally cooled to a temperature of about −2° C. or less, and in certain variations, optionally cooled to a temperature of about −5° C. or less. The cooling process may be performed in multiple cooling stages. In one example, the cooling stage may include three cooling phases, for example, in a first cooling stage, the temperature of the effluent stream may be reduced to a temperature of about 40° C. or less, in a second cooling stage, the temperature of the effluent stream may be reduced to a temperature of about 30° C. or less, and in a third cooling stage, the temperature of the effluent stream may be reduced to a temperature of about −2° C. or less.

[0086] At the predetermined temperature, lithium sulfate (Li2SO4) remains soluble in the water in the concentrated liquid stream, while sodium sulfate (Na2SO4) is solidified out of solution as a solid. The cooled concentrated liquid effluent stream may then be sent to a downstream crystallizer / crystallization unit that receives the concentrated liquid stream and produces sodium sulfate (Na2SO4) solids. In one embodiment, the crystallizer unit comprises a crystallizer / crystallization reactor or crystallizer / crystallization vessel and at least one upstream cooler for performing the cooling step (or the multiple stage cooling step described above). In another variation, the crystallization unit may have a crystallization vessel with a cooling jacket or other cooling mechanism. The at least one cooler may circulate a heat exchange medium, such as a heat exchange fluid (e.g., liquid water or air), such that the incoming concentrated liquid stream is cooled to a predetermined temperature before entering the crystallizer vessel. The cooler may have a heat exchange design such as those described above in the context of heat exchangers for heating liquid streams, or may include a thermoelectric cooler, or other designs known to those skilled in the art. In this manner, sodium sulfate (Na2SO4) may be removed from the effluent stream as sodium sulfate (Na2SO4) solid in the crystallizer vessel. The solubility of sodium sulfate (Na2SO4) in water at these predetermined temperatures is less than that of lithium sulfate (Li2SO4), which remains in solution. As one skilled in the art would understand, crystallization and precipitation are similar solidification processes. Without being bound to any particular theory, it is believed that sodium sulfate (Na2SO4) may solidify via a crystallization process, for example, through a physical change of state (e.g., a reduction in temperature or pressure, such as occurs in processes and systems according to certain embodiments of the present disclosure). In such a crystallization process, dissolved material (e.g., Na2SO4) may form a solid structure. The solid structure may be a crystalline structure, for example, having a regular, repeating arrangement of atoms or molecules. Crystal formation may occur slowly and the crystals may grow and appear as a solid mass. Thus, sodium sulfate (Na2SO4) solid may include crystalline sodium sulfate (Na2SO4).In other aspects, the solidification process may include processes that are more commonly understood to be precipitation processes, such as the settling of a solid material (e.g., Na2SO4 as a precipitate) from a liquid solution when there is an amount of material present that is greater than the solubility of the material in the liquid (e.g., the cooled liquid). The solid product (e.g., Na2SO4) produced by such processes may not be completely crystalline. Regardless of the mechanism, the solidification process contemplated by the present disclosure removes solid phase sodium sulfate (Na2SO4) from the liquid effluent stream.

[0087] In some embodiments, the purity of the sodium sulfate (Na2SO4) by-product is less than about 95% by weight. For example, the sodium sulfate by-product collected after the separation step may comprise about 95% by weight or more on a dry basis of the total weight of collected material and about 99% by weight or less of the total weight of the by-product collected. In some variations, about 60% by weight or more and about 80% by weight or less of the initial amount of sodium sulfate (Na2SO4) is removed from the effluent stream. Thus, in some variations, about 50 g / L or more and about 80 g / L or less of sodium sulfate (Na2SO4) may remain in the effluent stream after the separation step.

[0088] In the crystallizer vessel, sodium sulfate (Na2SO4) is a solid that can be separated from the concentrated liquid effluent stream. In some variations, a mother liquor and a supernatant stream can be generated in the crystallizer vessel or a downstream separation unit, such that the mother liquor contains sodium sulfate (Na2SO4) and a portion of the water. In some embodiments, the supernatant (second effluent stream) contains lithium sulfate (Li2SO4), a reduced concentration of sodium sulfate (Na2SO4), and a portion of the water. The crystallizer unit can include additional separation equipment (e.g., a centrifuge and / or a filter to separate solid sodium sulfate (Na2SO4), which in some variations can be beneficially reused as a by-product. Thus, in some variations, the process contemplates removing sodium sulfate (Na2SO4) solids from the effluent stream (second effluent stream and / or mother liquor). This can be done by centrifuging the by-product stream containing sodium sulfate (Na2SO4) solids and separating the liquid to collect the sodium sulfate (Na2SO4) solids. In some variations, the liquid (e.g., water) separated from the sodium sulfate (Na2SO4) solids or otherwise collected from the crystallizer vessel can be recycled to various parts of the system. For example, the separated liquid (e.g., water) can first be used in a system to cool the effluent liquid stream before entering the crystallizer vessel and then used in a downstream lithium recovery unit. It is also contemplated herein that the separated liquid (e.g., water) can optionally be combined with a second effluent stream (supernatant) generated in the crystallizer vessel and the combined stream can be sent to a downstream lithium recovery unit. Alternatively, the separated liquid (e.g., water) can be sent to a downstream lithium recovery unit without being combined with the second effluent stream.

[0089] In an alternative embodiment, solidifying sodium sulfate (Na2SO4) solids from the liquid stream comprises cooling the liquid stream and solidifying sodium sulfate (Na2SO4) from the cooled liquid stream in a crystallizer vessel as described herein to produce a third effluent stream. For example, the liquid stream is cooled to a temperature of about 20° C. or less, optionally cooled to a temperature of about 10° C. or less, optionally cooled to a temperature of about 5° C. or less, optionally cooled to a temperature of about 3° C. or less, optionally cooled to a temperature of about 0° C. or less, optionally cooled to a temperature of about −2° C. or less, and in one variation, optionally cooled to a temperature of about −5° C. or less. The step of cooling the liquid stream may be performed in multiple cooling stages as described herein. The cooled concentrated liquid effluent is then sent into a downstream crystallizer unit that receives the liquid stream, where solid sodium sulfate (Na2SO4) is produced as described above. As described above, the crystallizer unit includes a crystallizer reactor or crystallizer vessel as described herein and at least one upstream cooler as described herein for performing the cooling step (or the multiple stage cooling step as described above). In other variations, the crystallizer unit may have a crystallizer vessel with a cooling jacket or other cooling mechanism. Solid sodium sulfate (Na2SO4) may be separated or removed from the third effluent and / or mother liquor as described above. Additionally or alternatively, the liquid (e.g., water) separated from the sodium sulfate (Na2SO4) solids may optionally be combined with the third effluent stream (supernatant) produced in the crystallizer vessel, and the combined stream may be sent to a downstream evaporator. Alternatively, the separated liquid (e.g., water) may be sent to the evaporator without being combined with the third effluent stream. In any embodiment, the step of cooling the liquid stream may include a step of exchanging heat with the third effluent produced in the crystallizer vessel in at least one cooler (e.g., heat exchanger). It is contemplated herein that any of the various configurations provided herein may be suitable for any concentration of lithium present in the liquid stream.It will also be appreciated that one variation in which the step of cooling the liquid stream occurs prior to other processes, such as a step of concentration via evaporation, may be particularly advantageous when lower concentrations of lithium are present, given the difficulty in recovering lithium due to the very close solubility products of both the sodium and lithium salts.

[0090] The liquid stream (third effluent) having soluble lithium sulfate (Li2SO4) can then be sent to an evaporator / evaporator system as described herein. The evaporator / evaporator system evaporates a portion of the water in the third effluent stream to produce water vapor and a fourth effluent stream enriched in soluble lithium sulfate (Li2SO4) in the fourth effluent stream. Additionally or alternatively, the third effluent may be heated, for example to a temperature of about 90°C or higher, before being evaporated / before entering the evaporator / evaporator system. For example, heating the third effluent stream may include exchanging heat with the liquid stream in at least one cooler (e.g., heat exchanger), or the third effluent stream may be heated in a preheater as described above. Additionally or alternatively, a portion of the fourth effluent stream may serve as a reflux stream and be combined with the liquid stream before entering the crystallizer.

[0091] The concentrated liquid stream (the second effluent stream or the fourth effluent stream) having soluble lithium sulfate (Li2SO4) is then sent from the crystallizer unit or evaporator into a downstream lithium recovery unit, which may include a reactor, a heat source, and a solid-liquid separator component (e.g., a filtration unit including a filter, or a centrifuge, etc.).

[0092] The process also includes heating the effluent stream (the second effluent stream or the fourth effluent stream) and introducing sodium carbonate (Na2CO3) to produce lithium carbonate (Li2CO3) product. In one variation, the effluent stream is heated to a temperature of about 80° C. or more and less than about 100° C., optionally, to a temperature of about 80° C. or more and less than about 90° C. During the step of introducing sodium carbonate (Na2CO3), the temperature of the effluent stream is maintained throughout the mixing and reaction in the reactor.

[0093] For example, the methods described herein Sulfur Lithium oxide (Li2SO4) solution A process for precipitating lithium carbonate (Li2CO3) from may generally exhibit certain conditions according to the present teachings. In the precipitation of lithium carbonate (Li2CO3), a reaction occurs in solution between lithium sulfate (Li2SO4) and soda ash (Na2CO3). This promotes the formation of a dense precipitate with good settling, filtering, and washing properties, forming a wet cake with low water content. The chemical reaction in the aqueous solution that is believed to occur is as follows:

[0094] [ka]

[0095] In some embodiments, because lithium carbonate (Li2CO3) has significant solubility, especially in the mother liquor / liquid effluent stream, it is desirable to create a concentrated solution so that the amount of mother liquor / liquid stream being treated is minimized. The solubility of lithium carbonate (Li2CO3) in water or salt solutions decreases with increasing temperature. Therefore, to minimize solubility losses, it is advantageous to perform lithium precipitation, especially centrifugation, at elevated temperatures, e.g., from about 80° C. to about 100° C., and at ambient pressure conditions (e.g., 1 atm).

[0096] In some embodiments, a stoichiometric excess of sodium carbonate (Na2CO3) is introduced. For example, in some variations, the process further includes introducing a stoichiometric excess of sodium carbonate (Na2CO3) of about 10% to about 15%. For example, in some variations, it is desirable to have Na2CO3 in approximately 10% to about 15% stoichiometric excess over Li2SO4 since the increased carbonate ion concentration may reduce the solubility of Li2CO3 in the mother liquor / liquid stream. Under these conditions, it is calculated that about 15% of the lithium present in the starting Li2SO4 solution will remain unprecipitated in the mother liquor / liquid stream as soluble Li2CO3. This soluble lithium can be almost completely recovered by precipitation as fluoride, phosphate, or silicate, but none of these recovery procedures are economical for various reasons.

[0097] In one variation, the temperature in the lithium precipitation reactor may be from about 50° C. to about 70° C., and the residence time in the reactor may be from about 1 hour to about 2 hours, with the flow rate depending on the batch size being processed (and the residence time as described above).

[0098] Thus, in the present method and system: (i) (a) First, concentrate lithium sulfate (LiSO) in the liquid stream via evaporation, followed by solidifying sodium sulfate (NaSO) in a crystallizer unit; or (b) first solidifying sodium sulfate (Na2SO4) in a crystallizer unit, followed by concentrating lithium sulfate (Li2SO4) via evaporation in the liquid stream; Next, (ii) Higher levels of lithium can be recovered as lithium carbonate (LiCO3) by treating the remaining lithium sulfate (LiSO4) as described above in a manner that maximizes recovery of LiCO3 as a beneficially reusable product.

[0099] Finally, the process includes separating the lithium carbonate (Li2CO3) product from the effluent stream. The reactor receives the concentrated liquid stream (the second effluent stream or the fourth effluent stream) from the crystallizer unit or the evaporator along with a source of sodium carbonate (Na2CO3). Thus, a reaction occurs in the reactor to form a product stream containing lithium carbonate (Li2CO3). The lithium carbonate (Li2CO3) may be separated from the remaining liquid stream (the lithium carbonate (Li2CO3) product stream) via a filtration unit or other solid-liquid separation unit. Thus, a product stream is produced, which then passes through a filter and is separated into a concentrated liquid containing the lithium carbonate (Li2CO3) product and a waste stream. In some embodiments, the lithium carbonate (Li2CO3) product has a purity of about 80% by weight or more. For example, the collected lithium carbonate product after separation from the effluent stream and drying to remove water may constitute about 80% by weight or more on a dry basis of the total weight of the collected material. In one variation, the purity of the lithium carbonate (Li2CO3) product may be from about 80% to about 90% by weight of the total weight of the product collected.

[0100] Thus, according to various aspects of the present disclosure, lithium carbonate (Li2CO3) can be recovered as a recycled product from lithium ion battery waste streams and beneficially reused. Additionally, in some aspects, sodium sulfate (Na2SO4) can also be recovered as a respective by-product. The recovered sodium sulfate can be utilized as a recycled product in various industries, such as the detergent industry.

[0101] In various embodiments, the recovery of lithium as a recycled product from a lithium-ion battery waste stream as a feedstock may be performed in a batch or continuous system, or a combination of both. In such systems, the material streams are reacted continuously. The various stages or units are arranged to continuously provide intermediate processed streams to the next stage unit. As further described below, such stages may include, for example, an evaporation stage or unit (which may include a heating system), a crystallization stage or unit (which may include a cooling system), and a lithium recovery stage or unit. A stream from a given recovery stage or unit may be utilized to exchange heat with other streams being processed to improve the energy efficiency of the system when the heating or cooling process is performed. In a non-limiting example in which a 500 kg black mass waste stream is processed, the method and system may achieve a yield of approximately 1,000 kg / hr or 1 m 3 The material may be processed at a flow rate of up to 1000 / hr. However, as one skilled in the art will appreciate, the flow rate will depend on the total amount being processed and may be varied appropriately.

[0102] FIG. 1 is an example of a lithium recycling plant or system 50 according to an embodiment of the present disclosure for recovering lithium from a lithium ion battery waste stream. It may be used to implement various embodiments of the processes described above. A liquid stream 52 including lithium sulfate (Li2SO4), sodium sulfate (Na2SO4), and water (H2O) is pumped through a fluid conduit 56 via a pump 54. The fluid conduit 56 establishes fluid communication between various components in the system 50. Any of the pumps disclosed herein may include any suitable type of pump. For example, the pump may be a centrifugal pump, a positive displacement pump, an axial flow pump, etc. The liquid stream 52 enters a gas-liquid separator (e.g., an evaporator 60) via an inlet 62. The evaporator 60 has a first outlet 64 and a second outlet 66. Although not shown in FIG. 1, the liquid stream 52 may be heated as it enters the evaporator 60. In the evaporator 60, at least a portion of the water from the liquid stream 52 is volatilized or evaporated to produce a concentrated liquid or effluent stream and a water vapor or steam stream. The concentrated liquid stream passes through a first outlet 64 and the water vapor exits the evaporator 60 through a second outlet 66.

[0103] The concentrated liquid effluent stream then enters a crystallizer unit 70 downstream of the evaporator 60. The crystallizer unit 70 may include one or more coolers (generally indicated at 72) that receive and cool the concentrated liquid stream, for example as a heat exchanger. After passing through the cooler(s) 72, the concentrated liquid stream enters a crystallizer reactor or vessel 74 via inlet 76. Within the crystallizer vessel 74, the cooled concentrated liquid stream has a predetermined temperature that promotes the formation of sodium sulfate (Na2SO4) solids as described above. The solid sodium sulfate (and, optionally, mother liquor and / or supernatant) may be removed via a first outlet 78 and passed to a solid-liquid separator apparatus 80. It should be noted that, although not shown in FIG. 1, the system may further include a mother liquor storage vessel / tank (and a supernatant storage vessel / tank) in fluid communication with either the solid-liquid separator apparatus 80 and / or the crystallizer reactor or vessel 74, as would be understood by one of ordinary skill in the art. 1, solid-liquid separator apparatus 80 may be a centrifuge that separates sodium sulfate (Na2SO4) solids from the supernatant and / or mother liquor containing the concentrated lithium-containing product (e.g., lithium sulfate (Li2SO4)). In one variation, Table 2 below outlines suitable conditions for crystallization unit 70, including crystallization vessel 74.

[0104] [Table 2]

[0105] A concentrated liquid effluent stream (e.g., supernatant) having soluble lithium sulfate (LiSO4) in the crystallizer vessel 74 of the crystallizer unit 70 (second effluent stream) can then be removed via the second outlet 82 and sent to the downstream lithium recovery unit 90. Optionally, liquid (e.g., water) separated from the sodium sulfate (NaSO4) solids can be removed via the third outlet 83 and optionally combined with the second effluent stream, and the combined stream can then be sent to the downstream lithium recovery unit 90. Alternatively, the separated liquid (e.g., water) can be removed via the third outlet 83 and sent to the downstream lithium recovery unit 90 without being combined with the second effluent stream. The lithium recovery unit 90 may comprise (i) a reactor 92, (ii) a heat source 110 (e.g., a thermal jacket that may be heated with steam, or other heaters known in the art), and (iii) a solid-liquid separator (e.g., a filtration unit 120 comprising one or more filters downstream of the reactor 92). In particular, the solid-liquid separator may be a centrifuge or other solid-liquid separation unit known to those skilled in the art. The reactor 92 receives a concentrated liquid stream from the crystallizer unit 70 via an inlet 94. A source 96 of sodium carbonate (Na2CO3) is in communication with a second inlet 98 to the reactor 92 such that sodium carbonate (Na2CO3) is delivered to the reactor 92. The reactor 92 further comprises an agitator 100.

[0106] Thus, reactor 92 receives both the concentrated liquid effluent stream (second effluent) and sodium carbonate (Na2CO3). The concentrated liquid stream and sodium carbonate may be introduced into reactor 92 simultaneously or at different stages. In one variation, lithium carbonate (Li2CO3) is recovered from solution by first heating the solution containing lithium sulfate (Li2SO4) in reactor 92 to a temperature of about 80° C. or higher and about 90° C. or lower via heat source 110. The temperature may be maintained throughout the process. Sodium carbonate (Na2CO3) may be added to the heated solution in reactor 92, which may precipitate solid lithium carbonate (Li2CO3).

[0107] The contents described herein may be mixed by an agitator 100 extending into the reactor 92. In various embodiments, any of the agitators 100 disclosed herein may include a shaft 102 extending into the reactor 92, one or more impellers 104 attached to the shaft 102, and a motor 106 for rotating the shaft 102 and the impeller 104. In some embodiments, each impeller 104 may include one or more blades (or fins) for stirring the contents in the reactor. For example, one agitator may include two impellers (each impeller having three blades) spaced a predetermined distance apart. In particular, the agitator 100 may include other forms of mixers or agitators for the reactor (e.g., sonication, bubblers, etc.).

[0108] The reactor 92 may be agitated using an agitator 100 for a predetermined period of time (e.g., from about 30 minutes to about 45 minutes) and the temperature may be maintained at a desired temperature using a heat source 110. After the agitation period is completed, the lithium sulfate (Li2SO4) will precipitate as lithium carbonate (Li2CO3), as shown in the exemplary formulation above.

[0109] The lithium recovery unit 90 may further include a second pump 112. The second pump 112 pumps a concentrated liquid stream containing lithium carbonate (Li2CO3) exiting the reactor 92 into a filtration unit 120 containing one or more filters. 97The liquid effluent stream passes through the filter or filters in filtration unit 120 and is separated into a concentrate comprising recycled lithium carbonate (Li2CO3) solid product and a liquid waste stream 124 comprising water and other impurities that exit the filtration unit. The recycled lithium carbonate (Li2CO3) solid product may be stored as a cake or solid in a storage vessel 122. Impurities that pass through filtration unit 120 may be treated as desired, for example, sent to wastewater treatment and / or recycled to the reactor.

[0110] In various embodiments, any of the filters disclosed herein may include any suitable type of filter, for example, a filter may be a press filter, a hydraulic filter, a gravity filter, etc.

[0111] Thus, the present disclosure contemplates a system in which lithium carbonate is recovered using the method. The present technology provides a new method for recovering lithium carbonate (Li2CO3) from lithium ion batteries, providing economically attractive lithium carbonate (Li2CO3) to the market as a recycled product with good purity while reducing the current challenges associated with discharging lithium sulfate and sodium sulfate into the environment as waste products.

[0112] FIG. 2 shows a partial view of a lithium recycling plant or system for recovering lithium from lithium-ion battery waste streams similar to that shown in FIG. 1. However, the lithium recycling plant or system of FIG. 2 further includes a heating system incorporated as part of the evaporator system. As shown in FIG. 2, an alternative variation 150 of the system includes a heating system 152 that treats the liquid stream 52 before it enters the evaporator 60 according to certain variations of the present disclosure. For brevity, the same reference numbers are used to the extent that the components are the same as those shown in FIG. 1, and those components will not be reintroduced or described here unless a prominent feature or function is related to the variation shown in FIG. 2. In FIG. 2, the liquid stream 52 may enter the heating system 152, which includes a preheater 160. The liquid stream 52 may enter at a first inlet 162 and exit via a first outlet 164. The preheater 160 serves to heat the liquid stream 52 to a first predetermined temperature. As mentioned above, the preheater 160 may be a heater or may include a heat exchanger as shown. The heat exchanger may further pass another fluid stream through it to exchange heat with liquid stream 52. In this variation, preheater 160 includes a second inlet 166 and a second outlet 168 through which a separate heat exchange fluid stream flows to exchange heat with the liquid stream.

[0113] The liquid stream 52 then enters the heat exchanger 180 at a first inlet 182 and exits the heat exchanger 180 via a first outlet 184. The heat exchanger 180 serves to heat the liquid stream 52 to a second predetermined temperature. As will be further explained below, the heat exchanger 180 also passes another fluid stream through it for heat exchange with the liquid stream 52. In this variation, the heat exchanger 180 includes a second inlet 186 and a second outlet 188 through which a separate heat exchange fluid stream flows. More specifically, the second inlet 186 receives a compressed steam stream that exits the evaporator 60 at a second outlet 66 and then enters the compressor 190 where the steam is compressed to increase the pressure and temperature. The compressor 190 may be a variety of compressors known in the art. The various compressors include centrifugal compressors, reciprocating compressors, rotary compressors (rotor vane compressors, rolling compressors, single screw compressors, twin screw compressors), and orbital compressors (scroll compressors or trochoidal compressors). The compressed steam leaves the compressor 190 and enters the second inlet 186 of the heat exchanger 180 and exits via the second outlet 188.

[0114] In one variation, preferred conditions for the heating system 152 are outlined in Table 3 below.

[0115] [Table 3]

[0116] In one variation, the compressed stream may be reinjected into the fluid conduit 56 downstream of the preheater 160 and upstream of the evaporator 60. It mixes with the incoming liquid stream 52 to increase its temperature and pressure, thereby making evaporation more efficient. For example, approximately 83-85% of the steam may be recirculated and the temperature may be increased from about 92° C. to about 110° C., thereby improving the efficiency of the system.

[0117] The water-containing stream exiting heat exchanger 180 is then at least partially condensed from the steam (thus containing water condensate) and passes into second inlet 166 of preheater 160 and to second outlet 168. In preheater 160, the stream exchanges heat with passing liquid stream 52. In this manner, heat exchanger 180 may function as a condenser for the second stream. After being processed in evaporator 60, the concentrated liquid effluent stream may then be directed to crystallizer unit 70 for processing as described above.

[0118] Figure 3 shows a partial view of a lithium recycling plant or system 200 for recovering lithium from lithium ion battery waste streams similar to system 50 shown in Figure 1, except that lithium recycling plant or system 200 further includes a plurality of coolers as part of crystallizer unit 70A according to certain variations of the present disclosure. For brevity, to the extent that components are the same as those shown in Figures 1 and 2, the same reference numbers are used, and those components will not be reintroduced or described here unless a prominent feature or function is relevant to the variation shown in Figure 3.

[0119] 3 shows another variation of the system 200. The system variation 200 includes a heating device for the liquid stream 52 before the evaporator 60 and multiple coolers 72A included in the crystallizer unit 70A according to a variation of the present disclosure. For brevity, the same reference numbers are used to the extent that the components are the same as those shown in FIGS. 1 and 2, and those components will not be reintroduced or described here unless a prominent feature or function is related to the variation shown in FIG. 3.

[0120] Liquid stream 52 enters evaporator 60 where the concentrated liquid effluent stream exits through first outlet 64 to crystallizer unit 70A including multiple coolers 72A. Notably, crystallizer unit 70A may include only one cooler, but as shown has multiple separate coolers 72A or cooling heat exchangers. As shown, first cooler 240 receives concentrated liquid stream 242 which passes through first cooler 240 in a first direction. A first flow 244 of cooling heat exchange medium passes through first cooler 240 in a second direction in heat exchange relationship with concentrated liquid stream 242. The second direction may be in a co-current, counter-current, or cross-current relationship to the first direction. The heat exchangers may have any of the designs described above in the context of heat exchanger 180 of FIG. 2. In one example, the cooling heat exchange medium may be water in first cooler 240. The first cooler 240 may accomplish the first cooling stage described above in the context of the processes provided by certain embodiments of the present disclosure.

[0121] The second cooler 250 is downstream of the first cooler 240 and receives the concentrated liquid stream 242, which passes through the second cooler 250 in a first direction. A second stream 254 of a cooling heat exchange medium passes through the second cooler 250 in heat exchange relationship with the concentrated liquid stream 242. The second stream 254 may be a stream generated from the crystallizer reactor 74 (e.g., a liquid stream split off from a portion of the supernatant stream). The second direction of fluid flow within the second cooler 250 may be in a co-current, counter-current, or cross-current relationship to the first direction. The second cooler 250 may accomplish a second cooling stage as described above in the context of the processes provided by certain embodiments of the present disclosure.

[0122] The third cooler 260 is downstream of the second cooler 250 and receives the concentrated liquid stream 242 and further cools the concentrated liquid stream 242. In one variation, the flow rate through the third cooler 260 is 1 m 3 / hr and may have a temperature of about 92° C. A third stream 264 of cooling heat exchange medium passes through the third cooler 260 in a second direction in heat exchange relationship with the concentrated liquid stream 242. The second direction may be in a co-current, counter-current, or cross-current relationship to the first direction. In one example, the cooling heat exchange medium may be water in the third cooler 260. The third cooler 260 may accomplish the third cooling stage described above in the context of the processes provided by certain embodiments of the present disclosure.

[0123] Crystallizer unit 70A includes a centrifuge 80A that facilitates separation of sodium sulfate (Na2SO4) solids from the mother liquor / liquid stream in crystallization vessel 74. The liquid stream may then be recycled or sent, for example, as second stream 254 into a chiller system (e.g., into second chiller 250 described above). The sodium sulfate (Na2SO4)-depleted effluent stream (second effluent stream) may then exit crystallization vessel 74 at outlet 82 and enter a lithium recovery unit (not shown in FIG. 3, but shown in FIG. 1 as lithium recovery unit 90).

[0124] 3 shows another variation of the system 200. The system variation 200 includes a heating device for the liquid stream 52 before the evaporator 60 and multiple coolers 72A included in the crystallizer unit 70A according to a variation of the present disclosure. For brevity, the same reference numbers are used to the extent that the components are the same as those shown in FIGS. 1 and 2, and those components will not be reintroduced or described here unless a prominent feature or function is related to the variation shown in FIG. 3.

[0125] Liquid stream 52 is pumped via pump 54 into evaporator 60 where a concentrated liquid stream exits through first outlet 64 and a steam stream exits through second outlet 66. The concentrated liquid stream exiting first outlet 64 then proceeds to crystallizer unit 70A which includes at least one cooler 72A. Notably, crystallizer unit 70A has multiple separate cooling heat exchangers as shown, although it may include only one cooler. As shown, first cooler 240 receives concentrated liquid stream 242 which passes through first cooler 240 in a first direction. A first stream 244 of cooling heat exchange medium passes through first cooler 240 in a second direction in heat exchange relationship with concentrated liquid stream 242. The second direction may be in a co-current, counter-current, or cross-current relationship with respect to the first direction. In one example, the cooling heat exchange medium may be water in first cooler 240.

[0126] The second cooler 250 is downstream of the first cooler 240 and receives a concentrated liquid stream 242, which passes through the second cooler 250 in a first direction. A second stream 254 of a cooling heat exchange medium passes through the second cooler 250 in heat exchange relationship with the concentrated liquid stream 242. The second stream 254 may be a stream produced from the crystallizer reactor 74 (e.g., a liquid stream split off from a portion of the supernatant stream). The second direction of fluid flow within the second cooler 250 may be in a co-current, counter-current, or cross-current relationship to the first direction.

[0127] The third cooler 260 is downstream of the second cooler 250 and receives the concentrate liquid stream 242 and further cools the concentrate liquid stream 242. A third stream 264 of a cooling heat exchange medium passes through the third cooler 260 in a second direction in heat exchange relationship with the concentrate liquid stream 242. The second direction may be in a co-current, counter-current, or cross-current relationship to the first direction. In one example, the cooling heat exchange medium may be water in the third cooler 260.

[0128] Crystallizer unit 70A includes a centrifuge 80A that facilitates separation of sodium sulfate (NaSO) solids from the mother liquor / liquid stream in crystallization vessel 74. The liquid stream may then be sent into a cooler system (e.g., into second cooler 250, discussed above). As noted above, although not shown, crystallizer unit 70A may include one or more tanks for storing mother liquor, supernatant, etc.

[0129] In this manner, liquid stream 52 may be preheated by a preheater (e.g., preheater 160 in FIG. 2). In a variation, similar to FIG. 2, the heating source for preheater 160 is the secondary steam condensate of the system. Due to the complexity of liquid stream 52, the feed flow may be automatically adjusted to avoid shutdowns that may be caused by scaling and to increase system stability. Although not shown, in a variation, a vapor-liquid separator may be disposed downstream of the evaporator to receive the concentrated liquid and steam streams and further separate the vapor and liquid. The separator produces a concentrated liquid and vapor / steam stream. In an embodiment, the separator liquid level is maintained at a predetermined point.

[0130] In an embodiment, the evaporation system employs a forced circulation process by including a compressor. The evaporation system may include a forced circulation pump (e.g., pump 84 in FIG. 1) to ensure that the material flows quickly through the tubes of the heat exchanger(s) and help prevent the material from scaling and blocking the heat exchanger tubes. In an embodiment, the characteristics of the forced circulation process are as follows: First, a forced circulation evaporator is used to avoid boiling on the heat transfer surface, which would cause fouling formation or crystallization. Second, the circulation of the evaporated liquid in the device is mainly due to the forced flow of the circulation pump. Furthermore, the material does not evaporate in the heater (e.g., in the preheater 160 in FIG. 1), and the concentration does not change in the heat exchanger. Since the concentration will increase after flashing in the separation crystallizer, the material does not adhere to the heat exchange surface and does not cause fouling on the heat exchange surface. Finally, the body of the separation crystallizer has sufficient liquid / gas separation area and separation height, which can ensure long-term evaporation and stable discharge concentration. In one variation, the following Table 4 outlines the preferred conditions of the heater system 152 as shown in FIG.

[0131] [Table 4]

[0132] FIG. 4 illustrates a non-limiting example of a process 300 for recovering lithium according to a variation of the present disclosure, implemented in a system similar to that described in the context of FIG. 1 and FIG. 2. In the process 300, a liquid waste stream 302 is introduced into a preheater 330. The liquid waste stream 302 may generally have a solids content of about 13% to about 17%, a temperature of about 60° C., and may be introduced into the system at a flow rate of about 1,000 kg / hr. After leaving the preheater 330, the liquid waste stream 302 has a temperature of about 80° C. at point indicated at 310. The liquid waste stream 302 then enters a heat exchanger 332, where its temperature is increased to about 92° C. at point indicated at 312. The heat exchanger 332 also receives a compressed steam stream at point 314 at a temperature of about 110° C. After passing through heat exchanger 332, the steam undergoes an exothermic phase change and is condensed to liquid water, which may have a temperature of approximately 110° C. at point 316. This condensed water stream may then further enter preheater 330 to exchange heat with the incoming liquid waste stream 302. At point 318, the cooled condensate may have a temperature of approximately 50° C.

[0133] The liquid waste stream 302 then enters a separator / evaporator 334 where a portion of the water is removed to form a water vapor / steam stream and a concentrated liquid stream having lithium sulfate and sodium sulfate as described above. The steam stream leaving the evaporator 334 may have a temperature of about 92° C. at point 320 and may be processed in a compressor 336. After the steam is compressed and heated, it has the conditions described above at point 314 and then enters the heat exchanger 332. After leaving the evaporator 334, the liquid waste stream 302 has a temperature of about 92° C. at point 322 and then enters a cooling unit 338.

[0134] After being cooled in cooling unit 338, liquid waste stream 302 has a temperature of about 3° C. or more and about 20° C. or less at point 324. After passing through crystallization unit 340, which may include a solid-liquid separator and a reactor vessel (e.g., a decanter), by-product stream 350 is removed, comprising sodium sulfate salts that have solidified in crystallization unit 340.

[0135] Upon exiting the crystallization unit 340, the liquid waste stream 302 may have a temperature of about 20° C. at point 326. Finally, the liquid waste stream 302 enters the lithium recovery process 342. A sodium carbonate (Na2CO3) stream 352 is added during the lithium recovery process 342. A lithium carbonate (Li2CO3) product 354, which may have a purity of approximately 80-90%, is then produced. A residue solution waste stream 356 is also produced.

[0136] The calculated concentrations for this process are given in Table 5 below. The outlet for carbonate precipitate is shown in Figure 4. (Flow 352 for lithium precipitation with sodium carbonate Flow 326 Feed characteristics are shown.

[0137] [Table 5]

[0138] FIG. 5 illustrates an alternative example of a lithium recycling plant or system according to an embodiment of the present disclosure for recovering lithium from lithium ion battery waste streams. 50A5A, which may be used to carry out the various embodiments of the process described above. For brevity, to the extent that components are the same as those shown in FIG. 1, the same reference numbers are used, and those components will not be reintroduced or described here again unless a salient feature or function is relevant to the variation shown in FIG. 5. Liquid stream 52 is pumped in fluid conduit 56 via pump 54 into crystallizer unit 70. Crystallizer unit 70 includes one or more chillers (generally designated 72A) and a crystallizer vessel 74 that cools liquid stream 52 to solidify sodium sulfate (Na2SO4). Fluid conduit 56 allows the system 50A Fluid communication is established between the various components within the crystallizer vessel 74 of the crystallizer unit 70. A liquid effluent stream (e.g., supernatant) having soluble lithium sulfate (Li2SO4) in the crystallizer vessel 74 of the crystallizer unit 70 (third effluent stream) may then be removed via the second outlet 82. The third effluent stream then enters the evaporator 60 via the inlet 62. Optionally, liquid (e.g., water) separated from the sodium sulfate (Na2SO4) solids may be removed via the third outlet 83 and optionally combined with the third effluent stream, and the combined stream may then be sent downstream to the evaporator 60. Alternatively, the separated liquid (e.g., water) may be removed via the third outlet 83 and sent to the evaporator 60 without being combined with the third effluent stream.

[0139] In the evaporator 60, at least a portion of the water from the third effluent stream is volatilized or evaporated to produce a concentrated liquid stream or a fourth effluent stream and a water vapor or steam stream. The concentrated liquid stream (fourth effluent stream) passes through a first outlet 64 and the water vapor exits the evaporator 60 through a second outlet 66. In a variation, the third effluent stream may be heated prior to entering the evaporator 60, for example, by exchanging heat with the liquid stream 52 in a heating system 152 (not shown) or in one or more coolers (generally designated 72A). The concentrated liquid stream (fourth effluent stream) having soluble lithium sulfate (Li2SO4) is then sent downstream to a lithium recovery unit 90.

[0140] 6 is an alternative embodiment 50B of a lithium recycling plant or lithium recycling plant system according to an embodiment of the present disclosure for recovering lithium from lithium ion battery waste streams. It may be used to carry out the various embodiment processes described above. To the extent that components are the same as those shown in FIG. 1, the same reference numbers are used, and those components will not be reintroduced or described here unless a salient feature or function is related to the variation shown in FIG. 6. As shown in FIG. 6, a portion of the concentrated liquid stream (fourth effluent stream) may be sent as reflux stream 140 to and stored in vessel 142. The reflux stream 140 may be used, for example, to feed liquid stream 52 to a crystallization unit. 70 5. The liquid stream 52 may be combined with the liquid stream 52 for controlled heating to a constant temperature prior to introduction into the

[0141] In particular, any of the configurations in the various embodiments illustrated above may be combined with other configurations, even if not explicitly illustrated. Further, as one skilled in the art will appreciate, conventional components used in the system may not be illustrated, including valves, flow, temperature and pressure monitors, actuators, controllers, dryers, conventional accumulators, etc.

[0142] Furthermore, any of the above-mentioned systems may include an automatic control system. For example, each system may include a PLC automatic control system (e.g., marketed by Siemens) that allows automatic adjustment and control of incoming and outgoing material flows according to set (predetermined) values, automatic adjustment of liquid level in the main tank system, feedback of steam pipeline pressure signal to adjust steam flow, automatic system fault alarm, etc. Such an automated system can significantly reduce the labor allocation during operation and improve the accuracy and safety of the operation process.

[0143] The above-described description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or configurations of a particular embodiment are generally not limited to that particular embodiment, and even if not specifically shown or described, can be interchanged and used in a selected embodiment, where appropriate. Individual elements or configurations of the particular embodiment may be modified in many ways. Such variations should not be considered as departures from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure. [Brief description of the drawings]

[0144] [Figure 1] 1 shows a system for recovering lithium from waste streams derived from lithium-ion batteries according to a variation of the present disclosure. [Diagram 2] FIG. 1 shows a partial view of a system for recovering lithium according to an alternative variation of the present disclosure, including a heater system upstream of the evaporation system. [Diagram 3] FIG. 1 shows a partial view of a system for recovering lithium according to an alternative variation of the present disclosure, including a multi-stage cooler system upstream of a crystallizer vessel within a crystallization unit. [Figure 4] 1 shows an example of a process for recovering lithium according to certain variations of the present disclosure. [Diagram 5] 1 illustrates an alternative system for recovering lithium from waste streams derived from lithium-ion batteries according to a variation of the present disclosure, including a crystallization unit upstream of the evaporator. [Figure 6] FIG. 1 illustrates an alternative system for recovering lithium from waste streams derived from lithium ion batteries according to a variation of the present disclosure, including a crystallization unit upstream of the evaporator and further including a reflux stream in the system.

Claims

1. 1. A system for recovering lithium from a lithium ion battery waste stream, comprising: an evaporator having an inlet, a first outlet, and a second outlet; (i) at least one chiller; (ii) a crystallizer vessel comprising an inlet, a first outlet, and a second outlet; a crystallizer unit comprising: a lithium recovery unit downstream of the crystallizer unit or the evaporator, comprising: (i) a first inlet for receiving a second effluent stream from the crystallizer unit or a fourth effluent stream from the evaporator; ２ CO ３ a reactor having a second inlet for receiving the first sintered gas, an outlet, and an agitator; (ii) a heat source in thermal communication with the reactor; (iii) a solid-liquid separator in fluid communication with the reactor outlet, the product stream passing through the solid-liquid separator to separate lithium carbonate (Li ２ CO ３ ) a solid-liquid separator in which the product is separated into a retentate and a waste stream; A lithium recovery unit comprising: a fluid conduit for establishing fluid communication between the evaporator, the crystallizer unit, and the lithium recovery unit; at least one pump for circulating fluid within the fluid conduit; A system comprising: (i) Lithium sulfate (Li ２ SO ４ ), sodium sulfate (Na ２ SO ４ ), and water (H ２ The inlet of the evaporator receives a liquid stream comprising solid sodium sulfate (NaO), wherein at least a portion of the water from the liquid stream is evaporated in the evaporator to produce water vapor passing through the second outlet and an effluent stream passing through the first outlet, and the effluent stream is received by the crystallizer unit downstream of the evaporator to produce solid sodium sulfate (Na ２ SO ４ a first outlet of the crystallizer, the first outlet being connected to the inlet of the crystallizer vessel, the second outlet being connected to the inlet of the crystallizer vessel ... ２ SO ４ and removing said second effluent stream via said second outlet of said crystallizer vessel; or or (ii) The crystallizer unit receives the liquid stream and produces solid sodium sulfate (Na ２ SO ４ and cooling the liquid stream to form solid sodium sulfate (Na), the liquid stream being received by the inlet of the crystallizer vessel and the solid sodium sulfate (Na) being cooled through the first outlet of the crystallizer vessel. ２ SO ４ ), and a third effluent stream is removed via the second outlet of the crystallizer vessel, comprising lithium sulfate (Li ２ SO ４ ) and water (H ２ wherein the inlet of the evaporator receives the third effluent stream comprising water vapor and the fourth effluent stream comprises water vapor and a second outlet, and wherein at least a portion of the water from the third effluent stream is evaporated in the evaporator to produce water vapor passing through the second outlet and the fourth effluent stream passing through the first outlet; A system that is either

2. further comprising a heating system upstream of the evaporator; The system of claim 1 , wherein the heating system comprises at least one heater for heating the liquid stream prior to entering the evaporator.

3. At least one of the heaters is a preheater; the heating system further comprising a heat exchanger downstream of the preheater; The system of claim 2 , wherein the heat exchanger receives water vapor from the evaporator and the liquid stream in heat exchange relationship to increase a temperature of the liquid stream.

4. 4. The system of claim 3, wherein the heating system further comprises a compressor disposed between the evaporator and the heat exchanger, the compressor increasing at least one of a pressure and a temperature of the water vapor prior to entering the heat exchanger.

5. At least one of the coolers includes a heat exchanger; 2. The system of claim 1, wherein the heat exchanger receives the liquid stream and the third effluent in heat exchange relationship to reduce a temperature of the liquid stream and to increase a temperature of the third effluent prior to entering the evaporator.

6. 10. The system of claim 1, wherein the crystallizer unit further comprises a plurality of coolers upstream of the crystallizer vessel.

7. 7. The system of claim 6, wherein at least one of said plurality of coolers receives in heat exchange relationship a stream from said crystallizer vessel and said liquid stream to reduce a temperature of said liquid stream.

8. the crystallizer unit further comprises a centrifuge downstream of the first outlet of the crystallizer vessel; The centrifuge is configured to separate the solid sodium sulfate (Na ２ SO ４ ) and by-products including sodium sulfate (Na ２ SO ４ 10. The system of claim 1 , wherein the system separates liquids from solids.

9. the crystallizer unit further comprises a plurality of coolers upstream of the crystallizer vessel; 9. The system of claim 8, wherein at least one of the plurality of chillers receives liquid from the centrifuge in a heat exchange relationship with the liquid stream to reduce a temperature of the liquid stream.

10. 10. The system of claim 1, wherein the solid-liquid separator is selected from the group consisting of a pneumatic filter and a centrifuge.

11. 1. A method for recovering lithium from a lithium ion battery waste stream, comprising: Lithium sulfate (Li ２ SO ４ ), sodium sulfate (Na ２ SO ４ ), and water (H ２ From a liquid stream containing sodium sulfate (Na ２ SO ４ solidifying the mixture, (i) Lithium sulfate (Li) is added to generate water vapor and an effluent stream. ２ SO ４ ), sodium sulfate (Na ２ SO ４ ), and water (H ２ and cooling the effluent stream to extract sodium sulfate (NaSO) from the effluent stream in a crystallizer vessel such that a portion of the water in the liquid stream containing sodium sulfate (NaSO) is evaporated and a second effluent stream is produced. ２ SO ４ ) is solidified to produce sodium sulfate (Na ２ SO ４ solidifying the mixture; or (ii) The liquid stream is cooled to separate sodium sulfate (Na 2 SO 4 ) from the liquid stream in a crystallizer vessel such that a third effluent stream is produced. ２ SO ４ ) solids and evaporating a portion of the water in the third effluent stream to produce water vapor and a fourth effluent stream. ２ SO ４ and solidifying the mixture. The sodium sulfate (Na ２ SO ４ ) removing solids; and Lithium carbonate (Li ２ CO ３ The second effluent stream or the fourth effluent stream is heated to add sodium carbonate (Na) to the second effluent stream or the fourth effluent stream so as to produce a sodium carbonate (Na) product stream. ２ CO ３ ) introducing The lithium carbonate (Li ２ CO ３ ) from the product stream lithium carbonate (Li ２ CO ３ ) from the mixture; The process includes:

12. heating the liquid stream to a temperature of about 90° C. or greater prior to evaporating the liquid stream. or 12. The process of claim 11, further comprising the step of heating the third effluent to a temperature of about 90°C or greater prior to vaporizing the third effluent.

13. said step of heating said liquid stream further comprises exchanging heat with said water vapor produced during evaporation; or 13. The process of claim 12, wherein said step of heating said third effluent stream further comprises exchanging heat with said liquid stream.

14. 14. The process of claim 13, further comprising compressing the water vapor prior to said step of exchanging heat with the liquid stream.

15. The step of heating the second effluent stream or the fourth effluent stream may comprise heating the second effluent stream or the fourth effluent stream to a temperature of about 80° C. or greater but less than about 100° C. to produce sodium carbonate (Na ２ CO ３ 12. The process of claim 11, further comprising maintaining said temperature during said step of introducing.

16. Sodium carbonate (Na ２ CO ３ The step of introducing sodium carbonate (Na) in an amount of about 10% to about 15% stoichiometric excess ２ CO ３ 12. The process of claim 11, wherein the step of introducing

17. 12. The process of claim 11, wherein the step of cooling the effluent or liquid stream comprises cooling the effluent or liquid stream to a temperature of about 0°C or less.

18. The step of cooling is carried out in multiple cooling stages; In a first cooling stage, the temperature of the effluent stream or the liquid stream is reduced to a temperature of about 40° C. or less; In a second cooling stage, the temperature of the effluent stream or the liquid stream is reduced to a temperature of about 30° C. or less; 18. The process of claim 17, wherein in a third cooling stage, the temperature of the effluent stream or the liquid stream is reduced to a temperature of about -2°C or less.

19. 12. The method of claim 11, wherein said step of cooling said liquid stream comprises exchanging heat with said third effluent produced in said crystallizer vessel.

20. The sodium sulfate (Na ２ SO ４ The step of removing the sodium sulfate (Na ２ SO ４ ) solids-containing by-product stream is centrifuged to separate liquids and the sodium sulfate (Na ２ SO ４ 12. The method of claim 11 , wherein the method is carried out by collecting the solids.

21. The lithium carbonate (Li ２ CO ３ 12. The method of claim 11, wherein the product has a purity of about 80% by weight or greater.

22. The method of claim 11 further comprising the step of combining a portion of the fourth effluent stream with the liquid stream.

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