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 which is incorporated herein by reference.

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

[0003] This section provides background art related to the present disclosure, which 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 high energy density and battery voltage, low shelf life and discharge rate, and a wide operating temperature range. However, the estimated lifespan of such lithium-ion batteries is approximately 3 to 10 years, after which they are discarded. Recycling lithium-ion batteries (LIBs) is important because they often contain valuable metals (such as lithium, which can be wasted).

[0005] According to the U.S. Geological Survey, the lithium market is driven by demand from various industries, not only batteries but also ceramics, glass, and lubricants, among others. Lithium is typically extracted from brines and ores, with global crude lithium production reaching approximately 40,000 tons per year. However, demand for lithium is increasing every year, creating a need to recycle lithium and related components from lithium-ion batteries. Recycling lithium-ion batteries containing lithium would conserve the world's dwindling precious metal ores and reduce environmental challenges associated with e-waste disposal.

[0006] During hydrometallurgy and refining processes, lithium is typically obtained in the form of lithium carbonate (Li2CO3). Lithium carbonate is used as a precursor to form 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 would be desirable to be able to recycle waste streams from lithium-ion batteries to form 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 constituents.

[0008] In one embodiment, the present 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 including: (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 including lithium sulfate (LiSO), sodium sulfate (NaSO), and water (HO). The evaporator evaporates at least a portion of the water from the liquid stream to produce water vapor passing through the second outlet and an effluent stream passing through the first outlet. The crystallizer unit downstream of the evaporator receives the effluent stream and cools it to form solid sodium sulfate (NaSO). The inlet of the crystallizer vessel receives the effluent stream from the first outlet of the evaporator, removes a by-product comprising solid sodium sulfate (NaSO) 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 crystallizer unit receives the liquid stream and cools the liquid stream to form solid sodium sulfate (NaSO). The inlet of the crystallizer vessel receives the liquid stream, removes a by-product comprising solid sodium sulfate (NaSO) 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 comprising lithium sulfate (LiSO) and water (H0), and vaporizes at least a portion of the water from the third effluent stream 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 includes: (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, wherein a product stream passes through the solid-liquid separator to separate the product into a condensate comprising lithium carbonate (Li2CO3) product and a waste stream. The system further includes fluid conduits for establishing fluid communication between the evaporator, the crystallizer unit, and the lithium recovery unit, and at least one pump for circulating a fluid within the fluid conduits.

[0009] In one aspect, 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 a heat exchange relationship to increase the temperature of the liquid stream.

[0011] In a further aspect, the heating system further includes 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 before it enters the heat exchanger.

[0012] In a further aspect, at least one of the coolers includes a heat exchanger that receives the liquid stream and the third effluent stream in heat exchange relationship to reduce the temperature of the liquid stream and increase the 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 cooler of the plurality of coolers receives a stream from the crystallizer vessel and the liquid stream in a heat exchange relationship with each other and reduces the temperature of the liquid stream.

[0015] In one aspect, the crystallizer unit further comprises a centrifuge downstream of the first outlet of the crystallizer vessel, the centrifuge receiving the solid sodium sulfate (NaSO)-containing by-product and separating liquid from the sodium sulfate (NaSO) 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 the 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 present disclosure relates to a process for recovering lithium from a lithium-ion battery waste stream. In one aspect, the process includes solidifying sodium sulfate (NaSO) from a liquid stream containing lithium sulfate (LiSO), sodium sulfate (NaSO), and water (HO). In one variation, solidifying sodium sulfate (NaSO) includes evaporating a portion of the water in the liquid stream containing lithium sulfate (LiSO), sodium sulfate (NaSO), and water (HO) to produce water vapor and an effluent stream. The process further includes cooling the effluent stream and solidifying sodium sulfate (NaSO) from the effluent stream in a crystallizer vessel to produce a second effluent stream. In an alternative variation, solidifying sodium sulfate (NaSO) includes cooling the liquid stream to solidify sodium sulfate (NaSO) 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 (NaSO) solids from the second or third effluent stream, followed by heating the second or fourth effluent stream to introduce sodium carbonate (NaCO) into the second or fourth effluent stream to produce a lithium carbonate (LiCO) product stream. Finally, the process includes separating lithium carbonate (LiCO) from the lithium carbonate (LiCO) product stream.

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

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

[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 comprises 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 (NaCO).

[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 cooling step is carried out 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; and 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 (NaSO) solids from the second effluent stream or the third effluent stream is carried out by centrifuging a by-product stream containing the sodium sulfate (NaSO) solids to separate liquids and collect the sodium sulfate (NaSO) 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 to illustrate selected embodiments only, 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 this disclosure will be thorough and will fully convey its scope to those skilled in the art. Numerous specific details are set forth, such as examples of specific compositions, components, devices, and methods, 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 may be embodied 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 terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural forms as well, unless otherwise specified. The terms "comprises," "comprising," "including," and "having" are inclusive and thus specify the presence of stated features, elements, compositions, steps, integers, operations, and / or components, but do not exclude 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 an open-ended term used to describe and claim various embodiments described herein, although in certain aspects, the term may alternatively be construed as an even 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 present 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 characteristics, 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 characteristics are excluded from such an embodiment, but any compositions, materials, components, elements, features, integers, operations, and / or process steps that do not materially affect the basic and novel characteristics 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 to, connected to, or coupled to the other component, element, or layer, or there may be intervening elements or layers. 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. Other terms 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," and "third" may be used herein to describe various steps, elements, components, regions, layers, and / or sections; however, these steps, elements, components, regions, layers, and / or sections should not be limited by these terms unless otherwise specified. These terms are used only to distinguish one step, element, component, region, layer, or section from another step, element, component, region, layer, or section. Terms such as "first," "second," and other numerical terms used herein do not imply any sequence or order unless otherwise specified. Thus, a first step, element, component, region, layer, or section described below could 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," "lower side," "upper," "above," and the like may be used herein to describe and facilitate the description of one element or feature relative to another element or feature(s) shown 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 shown in the figures.

[0047] Throughout this disclosure, numerical values represent approximate measurements or limits on ranges encompassing slight deviations from a given value, embodiments having approximately the stated value, and embodiments having 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 instances by the term "about," regardless of whether "about" actually appears before the numerical value. "About" indicates that the stated numerical value allows for some slight imprecision (somewhat close to the exact value; approximately or reasonably close to a value; in the vicinity). Unless the imprecision introduced by "about" is otherwise understood in this ordinary sense in the art, "about," as used herein, indicates minimal variation that can occur from ordinary methods of measuring and using such parameters. For example, "about" can include a variation of no more than 5%, optionally a variation of no more than 4%, optionally a variation of no more than 3%, optionally a variation of no more than 2%, optionally a variation of no more than 1%, optionally a variation of no more than 0.5%, and in some embodiments, optionally a variation of no more than 0.1%.

[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, a range includes the endpoints and also includes the disclosure of all individual values and further divided ranges within the entire range. The disclosure of a value and range 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, if parameter X is exemplified herein as having a value A and parameter X is further 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 value ranges 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 may have values in other ranges, 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 specified, 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 containing 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, if element A and element B are exchanging various information, but the information sent from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that other information is not sent from element B to element A. Furthermore, for information sent from element A to element B, element B may send a request for 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 interchangeable with the term "circuit" 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 discrete circuit, an analog discrete circuit, or a mixed analog / digital discrete circuit; a digital integrated circuit, an analog integrated circuit, or a mixed analog / digital integrated circuit; a combinational 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 to be 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 a chip.

[0053] The modules and / or controllers may include one or more interface circuits. In some embodiments, the interface circuit may include a wired or wireless interface connected 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 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 code from multiple modules and / or controllers. The term group processor circuit encompasses a processor circuit that executes some or all 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 code from multiple modules and / or controllers. The term group memory circuit encompasses a memory circuit that stores some or all 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. As used herein, the term computer-readable medium does not encompass transitory electrical or electromagnetic signals propagating through a medium (e.g., on a carrier wave); therefore, the term computer-readable medium may be considered tangible and non-transitory. Non-limiting examples of non-transitory 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), volatile memory circuits (e.g., static random access memory circuits or dynamic random access memory circuits), magnetic storage media (e.g., analog or digital magnetic tape, or hard disk drives), and optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[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, flowchart components, and other elements described above function as software specifications that can be converted into a computer program by the routine work of a skilled engineer 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 rely on stored data. A computer program may encompass a basic input / output system (BIOS) that interacts with hardware in a special-purpose computer, device drivers that interact with specific devices in a special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0058] A computer program may include (i) parsed written text such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code executed by an interpreter; or (v) source code 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 a claim are intended to be a means-plus-function element within the meaning of 35 U.S.C. 112(f) unless an element is expressly recited using the phrase "means for," or in the case of a method claim using the phrase "act for" or "step for."

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

[0061] In various embodiments, the present disclosure contemplates forming one or more recycled products from a lithium-ion battery waste stream, wherein at least one of the recycled products includes lithium (Li). In some variations, the lithium (Li)-containing recycled product may include lithium carbonate (LiCO). The present disclosure also contemplates, in some variations, forming sodium sulfate (NaSO) as a beneficially reused by-product. Additionally, the present 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 are disassembled, crushed, and / or shredded. Such waste streams can be a material known as black mass that is intended for recycling. Collectively, black mass can include portions of one or more used lithium-ion batteries, including portions from lithium-ion batteries of various types (e.g., having various active materials). Black mass typically includes all active materials. As such, black mass can include anode active material and electrolyte components mixed with cathode active material. In some embodiments, 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. Spent lithium-ion batteries may include negative electrodes / anodes made from graphite, lithium titanate oxide (LiTiO-LTO), lithium metal, etc.

[0063] [Table 1]

[0064] Additionally, black mass may include electrolyte components including lithium salts, which may include fluorine, such as lithium hexafluorophosphate (LiPF). As a result, 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 should be understood that 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. By way of 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 certain embodiments, lithium is extracted from spent lithium-ion batteries (LIBs) by leaching to form lithium sulfate (LiSO), which is then reacted to recover lithium as lithium carbonate (LiCO).

[0066] In some embodiments, one or more separation and / or purification processes may be implemented upstream 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 comprising lithium (Li) (e.g., comprising one or more lithium-containing compounds). In some variations, the liquid stream derived from the lithium-ion battery waste stream comprises lithium sulfate (LiSO), sodium sulfate (NaSO), and water (HO). As a non-limiting example, see "PROCESSES AND SYSTEMS FOR PURIFYING LIQUID BODY WATER" filed February 22, 2023. 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 Ser. No. 18 / 112,676, entitled "PROCESS FOR REMOVING IMPURITIES IN THE RECYCLING OF LITHIUM-ION BATTERIES," PCT application No. PCT / SG2021 / 050496, entitled "PROCESS FOR REMOVING IMPURITIES IN THE RECYCLING OF LITHIUM-ION BATTERIES," published on March 3, 2022 as WO2022 / 045973, and PCT application No. PCT / SG2022 / 050014, entitled "PROCESS FOR RECYCLING LITHIUM IRON PHOSPHATE BATTERIES," filed on January 17, 2022. The relevant portions of each of these applications 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 lithium-ion battery-derived waste streams. In some of the 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 precipitated 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 solution in a liquid stream is too low to effectively recycle lithium. Furthermore, achieving effective separation of lithium (Li) and sodium (Na) from one another poses particular challenges, as both are Group I elements of the IUPAC periodic table. For example, sodium and lithium have extremely high solubility in many liquid media. Compounding the difficulty of lithium recovery is the close solubility products of both sodium and lithium salts, resulting in co-solidification of sodium and lithium in many solvent systems. In certain embodiments, the present 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 (LiSO) are extracted from a liquid stream containing sodium sulfate (NaSO) 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 at any of the values specified below. Separation efficiency may be calculated by comparing the initial amount of lithium present in the stream before treatment with 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 mass or volume), and x fis the final amount of lithium after the separation process is complete. 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 greater, optionally about 80% or greater, optionally about 85% or greater, optionally about 90% or greater, optionally about 95% or greater, optionally about 96% or greater, optionally about 97% or greater, optionally about 98% or greater, and in certain variations, optionally about 99% or greater, in terms of lithium.

[0071] Generally, the present disclosure contemplates an economical method and system / plant for recovering lithium-containing products (e.g., lithium carbonate (LiCO)) from lithium-ion battery waste streams by providing a water recovery process to concentrate the lithium species present, producing and recovering lithium carbonate (LiCO) as a product and, optionally, sodium sulfate (NaSO) as a by-product. The lithium carbonate (LiCO) 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 lithium recovery. In a variation, this 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., containing 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 comprising 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 (NaSO) from a liquid stream includes separating a portion of the water from a liquid stream containing lithium sulfate (LiSO), sodium sulfate (NaSO), and water (HO). 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 or effluent stream. In some variations, 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 from about 70% to about 90% by weight. After the separating step, the concentration of lithium sulfate (LiSO) in the effluent stream may be from about 8 g / L to about 14 g / L, and the concentration of sodium sulfate (NaSO) in the effluent stream may be from about 50 g / L to about 100 g / L. In this case, from 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 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 NaSO 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 exchangers. The liquid stream may proceed in a first direction, and the heat exchange medium in a second stream may proceed in a second direction. The second direction may be in a co-current, counter-current, or cross-current relationship with the first direction.

[0078] In some embodiments, the process is continuous and the water vapor / steam produced during the downstream evaporation step may be recycled or circulated through a heat exchanger device to exchange heat with the liquid stream. In some variations, 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 heat source may be, at least in part, the secondary steam condensate of the system produced 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 system stability, 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 within the heat exchanger(s) (e.g., within its tubing) and to prevent scaling of the material in the liquid stream and blocking of the internal flow conduits (e.g., tubing). In some variations, the optional forced circulation pump may increase the pressure of the treated stream to between about 0.2 MPa and about 0.25 MPa. In some embodiments, the forced circulation process for the evaporation system provided by certain 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 heat transfer surfaces, which could result in fouling or the formation of crystallization; (2) circulation of the evaporation liquid within the device is primarily due to the forced flow of the circulation pump; and (3) material in the liquid stream does not evaporate within the heater and does not change concentration within the heat exchanger. Alternatively, any separation device such as a crystallizer (crystallizer vessel, centrifuge, etc.) or in any of these devices After flushing within To,(4) The main 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 systems and methods with 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 Figure 2, secondary steam generated by evaporation of the liquid stream enters the vapor compressor and, after the compressor's operation, returns to the main heat exchanger 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. The liquid water 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] Although not shown, in a further embodiment, the non-condensable gases produced by the system are cooled by a non-condensable condenser (in the form of a heat exchanger), and the condensed water enters a condensate water tank, after which the non-condensable gases may be collected and 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 carried out 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 (LiSO) remains soluble in the water in the concentrated liquid stream, while sodium sulfate (NaSO) solidifies 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 (NaSO) solids. In some embodiments, the crystallizer unit comprises a crystallizer / crystallization reactor or vessel and at least one upstream cooler for performing the cooling step (or the multi-stage cooling step described above). In other variations, the crystallization unit may have a crystallization vessel equipped 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 (NaSO) can be removed from the effluent stream as solid sodium sulfate (NaSO) in the crystallizer vessel. The solubility of sodium sulfate (NaSO) in water at these predetermined temperatures is less than that of lithium sulfate (LiSO), which remains in solution. As one skilled in the art would understand, crystallization and precipitation are similar solidification processes. Without being bound by any particular theory, it is believed that sodium sulfate (NaSO) can 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., NaSO) can form a solid structure. The solid structure may be a crystalline structure, e.g., 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 (NaSO) solid may include crystalline sodium sulfate (NaSO).In other aspects, the solidification process may include processes 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 a greater amount of material is present than the material's solubility 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 (NaSO) 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 collected by-product. In some variations, about 60% by weight or more and about 80% by weight or less of the initial amount of sodium sulfate (NaSO) 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 (NaSO) may remain in the effluent stream after the separation step.

[0088] In the crystallizer vessel, sodium sulfate (NaSO) is a solid that can be separated from the concentrated liquid effluent stream. In some variations, mother liquor and supernatant streams may be produced in the crystallizer vessel or a downstream separation unit, such that the mother liquor contains sodium sulfate (NaSO) and a portion of the water. In some embodiments, the supernatant (second effluent stream) contains lithium sulfate (LiSO), reduced-concentration sodium sulfate (NaSO), and a portion of the water. The crystallizer unit may include additional separation equipment (e.g., a centrifuge and / or a filter for separating solid sodium sulfate (NaSO)). In some variations, the solid sodium sulfate (NaSO) can be beneficially recycled as a by-product. Thus, in some variations, the process contemplates removing sodium sulfate (NaSO) solids from the effluent streams (second effluent stream and / or mother liquor). This can be done by centrifuging a by-product stream containing sodium sulfate (NaSO) solids and separating the liquid to collect the sodium sulfate (NaSO) solids. In some variations, the liquid (e.g., water) separated from the sodium sulfate (NaSO) 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) produced in the crystallizer vessel, and this 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 (NaSO) solids from the liquid stream comprises cooling the liquid stream and solidifying sodium sulfate (NaSO) from the cooled liquid stream in a crystallizer vessel 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 some variations, optionally cooled to a temperature of about −5° C. or less. 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 (NaSO) 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 described above). In other variations, the crystallization unit may have a crystallization vessel equipped with a cooling jacket or other cooling mechanism. Solid sodium sulfate (NaSO) may be separated or removed from the third effluent and / or mother liquor described above. Additionally or alternatively, the liquid (e.g., water) separated from the sodium sulfate (NaSO) solids may optionally be combined with the third effluent stream (supernatant) produced in the crystallizer vessel, and this 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, cooling the liquid stream may include 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 before other processes, such as a concentration step 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 sodium and lithium salts.

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

[0091] The concentrated liquid stream (the second or fourth effluent stream) having soluble lithium sulfate (LiSO) is then sent from the crystallizer unit or evaporator into a downstream lithium recovery unit, which may include a reactor, a heat source, and solid-liquid separator components (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 (NaCO) to produce a lithium carbonate (LiCO) product. In one variation, the effluent stream is heated to a temperature of about 80° C. or greater and less than about 100° C., optionally, about 80° C. or greater and less than about 90° C. During the step of introducing sodium carbonate (NaCO), the temperature of the effluent stream is maintained throughout the mixing and reaction in the reactor.

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

[0094] [ka]

[0095] In certain embodiments, because lithium carbonate (Li2CO3) has significant solubility, particularly 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 processed 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 conduct lithium precipitation, particularly centrifugation, at elevated temperatures, e.g., from about 80°C to about 100°C, under ambient pressure conditions (e.g., 1 atmosphere).

[0096] In some embodiments, a stoichiometric excess of sodium carbonate (NaCO) is introduced. For example, in one variation, the process further includes introducing sodium carbonate (NaCO) in an amount of about 10% to about 15% stoichiometric excess. For example, in one variation, it is desirable to have NaCO in approximately 10% to about 15% stoichiometric excess over LiSO. This is because increased carbonate ion concentration can reduce the solubility of LiCO in the mother liquor / liquid stream. Under these conditions, it is calculated that about 15% of the lithium present in the starting LiSO solution remains in the mother liquor / liquid stream without precipitating as soluble LiCO. While this soluble lithium can be nearly completely recovered by precipitation as fluoride, phosphate, or silicate, 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 noted above).

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

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

[0100] Thus, according to various embodiments of the present disclosure, lithium carbonate (LiCO) can be recovered from lithium-ion battery waste streams as a recycled product and beneficially reused. Additionally, in certain embodiments, sodium sulfate (NaSO) 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, 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 thereof. In such systems, material streams are reacted continuously. 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 during heating or cooling processes. In a non-limiting example where a 500 kg black mass waste stream is processed, the method and system may achieve a recovery rate of approximately 1,000 kg / hr or 1 m 3 / 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 illustrates 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. This may be used to implement various aspects of the processes described above. A liquid stream 52, including lithium sulfate (LiSO), sodium sulfate (NaSO), and water (HO), is pumped through a fluid conduit 56 via a pump 54. The fluid conduit 56 establishes fluid communication between various components within 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, or the like. 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 upon entering the evaporator 60. In evaporator 60, at least a portion of the water from 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 first outlet 64 and the water vapor exits evaporator 60 through 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 designated 72) that receive and cool the concentrated liquid stream, e.g., as a heat exchanger. After passing through the cooler(s) 72, the concentrated liquid stream enters a crystallizer reactor or crystallizer vessel 74 via an inlet 76. Within the crystallizer vessel 74, the cooled concentrated liquid stream has a predetermined temperature that promotes the formation of the sodium sulfate (NaSO) solids described above. The solid sodium sulfate (and, optionally, the mother liquor and / or the supernatant) may be removed via a first outlet 78 and passed to a solid-liquid separator apparatus 80. Note 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 crystallizer 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 (NaSO) solids from a supernatant and / or mother liquor containing concentrated lithium-containing product (e.g., lithium sulfate (LiSO)). 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 (LiSO) in the crystallizer vessel 74 of the crystallizer unit 70 (second effluent stream) can then be removed via second outlet 82 and sent to a downstream lithium recovery unit 90. Optionally, the liquid (e.g., water) separated from the sodium sulfate (NaSO) solids can be removed via third outlet 83 and optionally combined with the second effluent stream, with the combined stream then being sent to the downstream lithium recovery unit 90. Alternatively, the separated liquid (e.g., water) can be removed via third outlet 83 and sent to the downstream lithium recovery unit 90 without being combined with the second effluent stream. Lithium recovery unit 90 may include (i) reactor 92, (ii) heat source 110 (e.g., a heat jacket that may be heated with steam, or other heater known in the art), and (iii) a solid-liquid separator (e.g., a filtration unit 120 comprising one or more filters downstream of 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. Reactor 92 receives a concentrated liquid stream from crystallizer unit 70 via inlet 94. A source 96 of sodium carbonate (NaCO) is in communication with a second inlet 98 to reactor 92 such that sodium carbonate (NaCO) is delivered to reactor 92. Reactor 92 further includes an agitator 100.

[0106] Thus, reactor 92 receives both the concentrated liquid effluent stream (second effluent) and sodium carbonate (NaCO). The concentrated liquid stream and sodium carbonate may be introduced into reactor 92 simultaneously or in different stages. In one variation, lithium carbonate (LiCO) is recovered from solution by first heating the solution containing lithium sulfate (LiSO) 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 (NaCO) may be added to the heated solution in reactor 92, which may precipitate solid lithium carbonate (LiCO).

[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 impellers 104. In some embodiments, each impeller 104 may include one or more blades (or fins) for stirring the contents within the reactor. For example, one agitator may include two impellers (each impeller having three blades) spaced a predetermined distance apart. Notably, the agitator 100 may include other forms of mixers or agitators for reactors (e.g., sonicators, bubblers, etc.).

[0108] Reactor 92 may be agitated using agitator 100 for a predetermined period of time (e.g., about 30 minutes to about 45 minutes), and the temperature may be maintained at a desired temperature using heat source 110. After the agitation period is complete, lithium sulfate (LiSO) will precipitate as lithium carbonate (LiCO), 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 the concentrated liquid stream containing lithium carbonate (LiCO) exiting the reactor 92 into a filtration unit 120 containing one or more filters. The filtration unit 120 is connected to the outlet of the reactor 92. 97The liquid effluent stream passes through the filter(s) in filtration unit 120 and is separated into a concentrate containing recycled lithium carbonate (LiCO) solid product and a liquid waste stream 124 containing water and other impurities that exit the filtration unit. The recycled lithium carbonate (LiCO) solid product may be stored as a cake or solid in 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, such as 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 the market with economically attractive lithium carbonate (Li2CO3) as a recycled product with good purity, while reducing current concerns about 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 integrated as part of the evaporator system. As shown in FIG. 2 , an alternative variation of the system 150 includes a heating system 152 that treats liquid stream 52 before it enters evaporator 60 according to certain variations of the present disclosure. 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 unless a prominent feature or function is relevant to the variation shown in FIG. 2 . In FIG. 2 , liquid stream 52 can enter heating system 152, which includes a preheater 160. Liquid stream 52 can enter at a first inlet 162 and exit via a first outlet 164. Preheater 160 serves to heat liquid stream 52 to a first predetermined temperature. As discussed above, preheater 160 may be a heater or, as shown, may include a heat exchanger. The heat exchanger may also 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] Liquid stream 52 then enters heat exchanger 180 at first inlet 182 and exits via first outlet 184. Heat exchanger 180 serves to heat liquid stream 52 to a second predetermined temperature. As will be further described below, heat exchanger 180 also passes another fluid stream through it to exchange heat with liquid stream 52. In this variation, heat exchanger 180 includes a second inlet 186 and a second outlet 188 through which a separate heat exchange fluid stream flows. More specifically, second inlet 186 receives a compressed steam stream. The compressed steam stream exits evaporator 60 at second outlet 66 and then enters compressor 190, where the steam is compressed to an increased pressure and temperature. Compressor 190 may be any of a variety of compressors known in the art. The various compressors include centrifugal compressors, reciprocating compressors, rotary compressors (rotary vane compressors, rolling compressors, single screw compressors, twin screw compressors), and orbital compressors (scroll compressors or trochoidal compressors). The compressed steam exits 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, the following Table 3 outlines suitable conditions for the heating system 152:

[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, increasing its temperature and pressure, thereby making evaporation more efficient. For example, approximately 83-85% of the steam may be recirculated, increasing the temperature 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 (and thus contains water condensate) and passes into second inlet 166 and to second outlet 168 of preheater 160. 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 lithium recycling system 200 for recovering lithium from a lithium-ion battery waste stream similar to system 50 shown in Figure 1, except that lithium recycling plant or lithium recycling system 200 further includes a plurality of coolers as part of crystallizer unit 70A according to a variation 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 illustrates another system variation 200, which includes a heating device for liquid stream 52 before evaporator 60 and multiple coolers 72A included in crystallizer unit 70A, according to a variation of the present disclosure. For brevity, to the extent that components are the same as those shown in FIGS. 1 and 2, the same reference numbers are used, and those components will not be reintroduced or described here unless a distinctive feature or function is relevant 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 and is sent to crystallizer unit 70A, which includes 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 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. 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] Second cooler 250 is downstream of first cooler 240 and receives concentrated liquid stream 242. Concentrated liquid stream 242 passes through second cooler 250 in a first direction. A second stream 254 of a cooling heat exchange medium passes through second cooler 250 in heat exchange relationship with concentrated liquid stream 242. Second stream 254 may be a stream produced from crystallizer reactor 74 (e.g., a liquid stream split off from a portion of the supernatant stream). The second direction of fluid flow within second cooler 250 may be in a cocurrent, countercurrent, or crosscurrent relationship with the first direction. Second cooler 250 may accomplish the second cooling stage described above in the context of the process 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 process provided by certain embodiments of the present disclosure.

[0123] 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 recycled, for example, sent as second stream 254 into a chiller system (e.g., into second chiller 250 described above). The sodium sulfate (NaSO)-depleted effluent stream (second effluent stream) then exits crystallization vessel 74 at outlet 82 and may enter a lithium recovery unit (not shown in FIG. 3, but shown in FIG. 1 as lithium recovery unit 90).

[0124] 3 illustrates another system variation 200, which includes a heating device for liquid stream 52 before evaporator 60 and multiple coolers 72A included in crystallizer unit 70A, according to a variation of the present disclosure. For brevity, to the extent that components are the same as those shown in FIGS. 1 and 2, the same reference numbers are used, and those components will not be reintroduced or described here unless a distinctive feature or function is relevant 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, although it could 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] Second cooler 250 is downstream from first cooler 240 and receives concentrated liquid stream 242. Concentrated liquid stream 242 passes through second cooler 250 in a first direction. A second stream 254 of a cooling heat exchange medium passes through second cooler 250 in heat exchange relationship with concentrated liquid stream 242. Second stream 254 may be a stream produced from crystallizer reactor 74 (e.g., a liquid stream split off from a portion of the supernatant stream). The second direction of fluid flow within second cooler 250 may be in a co-current, counter-current, or cross-current relationship to the first direction.

[0127] A third cooler 260 is downstream from the second cooler 250 and receives 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 with 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, described 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 one variation, similar to FIG. 2 , the heat source for preheater 160 is the secondary steam condensate of the system. Due to the complexity of liquid stream 52, the supply flow may be automatically adjusted to avoid shutdowns that may be caused by scaling and to increase system stability. Although not shown, in one variation, a vapor-liquid separator may be positioned 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 one embodiment, the separator liquid level is maintained at a predetermined point.

[0130] In some embodiments, the evaporation system employs a forced circulation process by including a compressor. The evaporation system may also include a forced circulation pump (e.g., pump 84 in FIG. 1 ) to ensure a high flow rate of the material through the heat exchanger tubes (one or more), helping to prevent the material from scaling and potentially blocking the heat exchanger tubes. In some embodiments, the forced circulation process has the following characteristics: First, a forced circulation evaporator is used, avoiding boiling on the heat transfer surfaces, which could lead to fouling or crystallization. Second, the circulation of evaporated liquid within the system is primarily due to the forced flow of the circulation pump. Furthermore, the material does not evaporate in the heater (e.g., preheater 160 in FIG. 1 ), and its concentration does not change within the heat exchanger. Because its concentration increases after flashing in the separation crystallizer, the material does not adhere to the heat exchange surfaces and does not cause fouling on the heat exchange surfaces. 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 for a heater system 152 such as that shown in Figure 1.

[0131] [Table 4]

[0132] FIG. 4 shows one 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 FIGS. 1 and 2. In process 300, a liquid waste stream 302 is introduced into a preheater at 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 exiting preheater 330, liquid waste stream 302 has a temperature of about 80° C. at point 310. Liquid waste stream 302 then enters heat exchanger 332, where its temperature is increased to about 92° C. at point 312. Heat exchanger 332 also receives a compressed steam stream at point 314 having a temperature of about 110° C. After passing through heat exchanger 332, the steam undergoes an exothermic phase change and condenses into 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 exiting the evaporator 334 may have a temperature of approximately 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 a heat exchanger 332. After exiting the evaporator 334, the liquid waste stream 302 has a temperature of approximately 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 solidified in crystallization unit 340.

[0135] Upon exiting crystallization unit 340, liquid waste stream 302 may have a temperature of approximately 20°C at point 326. Finally, liquid waste stream 302 enters lithium recovery process 342. Sodium carbonate (NaCO) stream 352 is added during lithium recovery process 342. Lithium carbonate (LiCO) 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 shown in Table 5 below. The outlet for carbonate precipitates 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 a lithium-ion battery waste stream. 50A5A, which can 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 numerals will be used, and those components will not be reintroduced or described here unless a distinctive feature or function is relevant to the variation shown in FIG. 5A. Liquid stream 52 is pumped in fluid conduit 56 via pump 54 into crystallizer unit 70. Crystallizer unit 70 includes one or more coolers (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 various components within the crystallizer vessel 74 of the crystallizer unit 70. A liquid effluent stream (e.g., supernatant) having soluble lithium sulfate (LiSO) in the crystallizer vessel 74 (third effluent stream) can then be removed via second outlet 82. The third effluent stream then enters the evaporator 60 via inlet 62. Optionally, liquid (e.g., water) separated from the sodium sulfate (NaSO) solids can be removed via third outlet 83 and optionally combined with the third effluent stream, with the combined stream then being sent downstream to the evaporator 60. Alternatively, the separated liquid (e.g., water) can be removed via third outlet 83 and sent to the evaporator 60 without being combined with the third effluent stream.

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

[0140] 6 is an alternative example 50B of a lithium recycling plant or lithium recycling plant system according to an embodiment of the present disclosure for recovering lithium from a lithium-ion battery waste stream, which may be used to implement the various process embodiments described above. To the extent that components are the same as those shown in FIG. 1 , the same reference numerals are used, and those components will not be reintroduced or described here unless a distinctive feature or function is relevant 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. Reflux stream 140 may be used, for example, to feed liquid stream 52 to a crystallization unit. 70 The liquid stream 52 may be combined with the liquid stream 52 for controlled heating to a constant temperature before being introduced into the

[0141] In particular, any of the configurations in the various embodiments shown above may be combined with other configurations, even if not explicitly shown. Further, as one skilled in the art will appreciate, conventional components used in the system may not be shown, 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., one marketed by Siemens) that allows automatic adjustment and control of incoming and outgoing material flows according to set (predetermined) values, automatic adjustment of liquid levels in the main tank system, feedback of steam pipeline pressure signals to adjust steam flow, automatic system fault alarms, etc. Such an automated system can significantly reduce labor allocation during operation and improve the accuracy and safety of the operation process.

[0143] The foregoing 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 components of a particular embodiment are generally not limited to that particular embodiment and, even if not specifically shown or described, can be interchangeable, where appropriate, and used in a selected embodiment. Individual elements or components of the particular embodiment may be modified in many ways. Such variations are not to be considered departures from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure. [Brief explanation 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. [Figure 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. [Figure 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 illustrates an example of a process for recovering lithium according to certain variations of the present disclosure. [Figure 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] 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) a crystallizer vessel having an inlet, a first outlet, and a second outlet; (ii) a plurality of coolers located upstream of the crystallizer vessel; a crystallizer unit comprising: a lithium recovery unit downstream of the crystallizer unit or the evaporator, comprising: (i) a first inlet for receiving the second effluent stream from the crystallizer unit or the fourth effluent stream from the evaporator; ２ CO ３ a reactor having a second inlet for receiving the first component, 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 outlet of the reactor, the product stream passing through the solid-liquid separator to form a solid-liquid separator containing lithium carbonate (Li ２ CO ３ ) a solid-liquid separator in which the product is separated into a concentrate 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 said 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 (Na), 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 and crystallized to produce solid sodium sulfate (Na). ２ SO ４ the inlet of the crystallizer vessel receives the effluent stream from the first outlet of the evaporator and cools the effluent stream to below 5°C to form solid sodium sulfate (Na 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 below 5°C 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 formed through the first outlet of the crystallizer vessel. ２ SO ４ a third effluent stream is removed via the second outlet of the crystallizer vessel, and a by-product comprising lithium sulfate (Li ２ SO ４ ) and water (H ２ the inlet of the evaporator receives the third effluent stream comprising: 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; 3. 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 the 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 the pressure and temperature of the water vapor before it enters the heat exchanger.

5. At least one of the plurality of coolers includes a heat exchanger; 10. The system of claim 1, wherein the heat exchanger receives the liquid stream and the third effluent stream in heat exchange relationship to reduce the temperature of the liquid stream and increase the temperature of the third effluent stream prior to entering the evaporator.

6. The system described in claim 1, wherein the plurality of coolers comprises a first cooling vessel that cools the effluent stream or the liquid stream to a temperature of approximately 40°C or less, a second cooling vessel that cools the effluent stream or the liquid stream to a temperature of approximately 30°C or less, and a third cooling vessel that cools the effluent stream or the liquid stream to a temperature of approximately -2°C or less.

7. 10. The system of claim 1, wherein at least one of the plurality of coolers receives a stream from the crystallizer vessel and the liquid stream in heat exchange relationship to reduce the temperature of the liquid stream.

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

9. The system described in claim 8, wherein at least one of the plurality of coolers receives liquid from the centrifuge in a heat exchange relationship with the liquid flow and reduces the temperature of the liquid flow.

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 process 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 produce 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 below 5°C to remove sodium sulfate (NaSO) from the effluent stream in a crystallizer vessel, thereby evaporating a portion of the water in the liquid stream containing sodium sulfate (NaSO) and producing a second effluent stream. ２ SO ４ ) is solidified to obtain sodium sulfate (Na ２ SO ４ solidifying the mixture; or (ii) The liquid stream is cooled to below 5°C and sodium sulfate (Na ) is extracted from the liquid stream in a crystallizer vessel to produce a third effluent stream. ２ SO ４ and evaporating a portion of the water in the third effluent stream to produce water vapor and a fourth effluent stream. ２ SO ４ solidifying the mixture; the sodium sulfate (Na ２ SO ４ ) removing solids; Lithium carbonate (Li ２ CO ３ heating the second effluent stream or the fourth effluent stream to add sodium carbonate (Na ) to the second effluent stream or the fourth effluent stream to produce a sodium carbonate (Na ) product stream. ２ CO ３ ) introducing The lithium carbonate (Li ２ CO ３ ) from the product stream to lithium carbonate (Li ２ CO ３ ) and separating the The process includes:

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

13. the step of heating the liquid stream further comprises exchanging heat with the 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 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 at least about 80° C. but less than about 100° C. to produce sodium carbonate (Na ２ CO ３ 12. The process of claim 11, wherein the step of: maintaining said temperature during said step of introducing

16. Sodium carbonate (Na ２ CO ３ The step of introducing sodium carbonate (Na ２ CO ３ 12. The process of claim 11, wherein

17. 12. The process of claim 11, wherein 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.

18. the step of cooling is carried out in multiple cooling stages; a first cooling stage in which the temperature of the effluent stream or the liquid stream is reduced to a temperature of about 40° C. or less; a second cooling stage in which 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 process of claim 11, wherein said step of cooling said liquid stream comprises exchanging heat with said third effluent stream 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 the liquid, and the sodium sulfate (Na ２ SO ４ 12. The process of claim 11 , wherein the solids are collected by

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

22. 12. The process of claim 11, further comprising combining a portion of the fourth effluent stream with the liquid stream.

Images