Systems and methods for extraction of lithium from spodumene

Abstract

Systems and methods for extraction of lithium from spodumene, and more particularly, systems and methods systems and methods for extraction of lithium from spodumene by Joule heating or electrothermal chlorination.

Description

Attorney Docket No.: 072174-07101 SYSTEMS AND METHODS FOR EXTRACTION OF LITHIUM FROM SPODUMENE CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] The application claims priority to U.S. Patent Appl. Serial No.63 / 669,556, filed July 10, 2024, entitled “Systems And Methods For Extraction Of Lithium From Spodumene,” which patent application is commonly owned by the owner of the present invention and is incorporated herein in its entirety. TECHNICAL FIELD

[0002] The present invention relates to systems and methods for extraction of lithium from spodumene, and more particularly, systems and methods systems and methods for extraction of lithium from spodumene by Joule heating or electrothermal chlorination. GOVERNMENT INTEREST

[0003] This invention was made with government support under Grant No. FA9550-22-1- 0526, awarded by the United States Air Force Office of Scientific Research, Grant No. W912HZ-21-2-0050, awarded by the U.S. Army Corps of Engineers, Engineer Research and Development Center, and Grant No. HR00112290122, awarded by the Department of Defense, Defense Advanced Research Projects Agency. The United States government has certain rights in the invention. BACKGROUND

[0004] Li is an essential component in lithium-ion and lithium-metal batteries, which account for most portable renewable energy storage systems, facilitating the ubiquitous internet of things and electric vehicles. [Olivetti 2017; Trahey 2020]. This has led to a global surge in Li demand. [Alessia 2021]. The supply of Li, however, is confronted with obstacles, including a lack of raw materials, the need for remote mining, environmental concerns, and the complexity of Li extraction and separation. [Olivetti 2017; Xu 2020].

[0005] Efficient separation of Li is crucial to prevent supply chain disruptions and to minimizeAttorney Docket No.: 072174-07101 secondary waste streams, while economically incentivizing the mining industry. [Reck 2012; Graedel 2015]. Primary natural sources of Li are in brine deposits and mineral ores. See FIGS. 1A-1B. [Yang 2018; Tadesse 2019; Vera 2023; Li 2024; Yong 2024; Zhang 2024]. Two-thirds of Li that is processed worldwide is extracted from brines even though the separation process is slow, taking 12 to 18 months in large-area evaporation ponds, and brines have low Li concentrations of only 1 to 2 wt%. [Vera 2023; Flexer 2018].

[0006] Conversely, Li ores such as spodumene, lithium aluminum inosilicate, LiAl(SiO3)2, have double the Li content of brines, reaching ~4 wt% of the complex, and ~8 wt% of the total metal content in the ore. However, only one-third of Li that is obtained worldwide is extracted from spodumene because of the increased complexity in isolation using this ore instead of brines. [Tadesse 2019; Dessemond 2019; Fosu 202; Zhou 2024]. Many wet strategies, including H2SO4roasting [Meshram 2014; Yan 2012; Guo 2017; Kuang 2018; Lajoie-Leroux 2018], fluorination [Rosales 2014; Rosales 2019], chlorination [Barbosa 2015; Barbosa 2014], carbonation [Dessemond 2019; Chen 2011; dos Santos 2019], froth flotation [Zhu 2020; Xie I 2021; Xie II 2021], and electrochemical leaching [Zhang 2024] have been used to separate Li from spodumene.

[0007] Among them, the H2SO4roasting process has been the standard method for Li separation from mineral ores including spodumene, but H2SO4 roasting requires extended heating cycles up to 1,100 °C, excess acid, and several chemical additives, while generating cumbersome secondary waste streams as seen in FIG. 1A. [Meshram 2014; Yan 2012; Guo 2017; Kuang 2018; Lajoie-Leroux 2018; Rosales 2014; Rosales 2019; Barbosa 2015; Barbosa 2014].

[0008] The H2SO4 process is initiated by heating a rotary kiln to 1,100 °C for 30 minuteswhere α-spodumene is converted to β-spodumene. β-spodumene is then roasted with concentrated H2SO4in an indirect kiln, or the calciner, at 200–250 °C for 10–60 minutes.Attorney Docket No.: 072174-0710130–40% excess H2SO4 ensures enoughprotons are available to react with present impurities.This step generates water-soluble lithium sulfate(Li2SO4) for extraction from the slurrymixture. [Rioyo 2022; Kuu 2023]. After adding soda ash (Na2CO3) between 90–100 °C, Liprecipitates as lithium carbonate (Li2CO3). Although this method can extract Li, the operatingtemperaturerange, duration, and use of large amounts of acid limit its wide application,increasing the cost of extracting Li and causing environmental hazards. [Swain 2017;Battistel2020].

[0009] Thus a need remains for improved systems and methods for extraction of lithium. SUMMARY OF THE INVENTION

[0010] The present invention relates to systems and methods for extraction of lithium from spodumene, and more particularly, systems and methods for extraction of lithium from spodumene by Joule heating or electrothermal chlorination (which is Joule heating in the presence of a chlorinating source).

[0011] In general, in one embodiment, the invention features a method that includes selecting a material or mixture that includes α-spodumene. The method further includes Joule heating the material or mixture to convert the α-spodumene to β-spodumene.

[0012] Implementations of the invention can include one or more of the following features:

[0013] The method can further include leaching the β-spodumene with an acid.

[0014] The acid can be a diluted acid. The diluted acid can have a molar concentration of at most 3 M.

[0015] The β-spodumene can be stirred with an acid to obtain lithium salts dissolved in the acid.

[0016] The molar concentration of the diluted acid can be at most 1 M.

[0017] The acid can be 1 M HCl.

[0018] The acid can be selected from the group consisting of hydrochloric acid, acetic acid,Attorney Docket No.: 072174-07101 sulfuric acid, mineral acid, and organic acid.

[0019] The acid can be diluted with water.

[0020] The Joule heating can be flash Joule heating.

[0021] The Joule heating can be performed at a Joule heating temperature of at least 1100 °C.

[0022] The materials or mixture can be small particles.

[0023] The method can include obtaining the small particles from a spodumene concentrator plant.

[0024] The method can include obtaining the small particles from discarded tailings.

[0025] The discarded tailings can have a particle size of at most 100 microns.

[0026] The discarded tailings can have a particle size of at most 50 microns.

[0027] The discarded tailings can have a particle size of at most 25 microns.

[0028] The discarded tailings can have a particle size of at most 20 microns.

[0029] The small particles can have a particle size between 0.1 and 50 microns.

[0030] In general, in another embodiment, the invention features a method that includes selecting a material or mixture including α-spodumene, β-spodumene, or a combination thereof. The method further includes Joule heating the material or mixture in the presence of a chlorine source to afford a volatile lithium chloride species that separates by volatilization from solid residue.

[0031] Implementations of the invention can include one or more of the following features:

[0032] The chlorine source can be selected from the group consisting of chlorine gas, gas sources of chlorine atoms, solid sources of chlorine atoms, and liquid sources of chlorine atoms.

[0033] The chlorine source can be chlorine gas.

[0034] The chlorine source can be sodium chloride or organochloride.

[0035] The chlorine source can be selected from the group consisting of poly(vinyl chloride) (PVC), poly(vinylidene dichloride) (PVDC), and chlorinated poly(vinyl chloride) (CPVC).Attorney Docket No.: 072174-07101

[0036] The chlorine source selected from the group consisting of poly(vinyl chloride) (PVC), poly(vinylidene dichloride) (PVDC), and chlorinated poly(vinyl chloride) (CPVC) can be used in its waste form.

[0037] The Joule heating of the material can be performed in a reaction chamber. The volatile lithium chloride species can be separated by volatilization from the solid residue in the reaction chamber.

[0038] The solid residue can include a solid residue material selected from the group consisting of SiO2, Al2O3, and a combination thereof.

[0039] The Joule heating can be flash Joule heating.

[0040] The Joule heating can be performed at a Joule heating temperature of at least 500 °C.

[0041] The Joule heating temperature can be at least 1350 °C.

[0042] The Joule heating temperature can be at least 1550 °C.

[0043] The Joule heating temperature can be at most 2100 °C.

[0044] The method can further include rinsing the volatile with water to separate the Li.

[0045] The materials or mixture can be small particles.

[0046] The method can include obtaining the small particles from a spodumene concentrator plant.

[0047] The method can include obtaining the small particles from discarded tailings.

[0048] The discarded tailings can have a particle size of at most 100 microns.

[0049] The discarded tailings can have a particle size of at most 50 microns.

[0050] The discarded tailings can have a particle size of at most 25 microns.

[0051] The discarded tailings can have a particle size of at most 20 microns.

[0052] The small particles can have a particle size between 0.1 and 50 microns.

[0053] In general, in another embodiment, the invention features a system that performs one or more of the above-described methods.Attorney Docket No.: 072174-07101 BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIGS. 1A-1G show FJH-Cl2for separation and recovery of Li. FIG. 1A shows a schematic of a prior art process flow of the Li separation from spodumene by industrial methods. FIG.1B shows a schematic of a prior art process flow of the Li separation from brine by industrial method. FIG.1C shows a schematic of a process flow of the Li separation from spodumene by FJH-Cl2 method. FIG. 1D shows a schematic diagram of a FJH-Cl2 process, where spodumene is placed on the carbon paper and reacts with Cl2. FIG. 1E shows a temperature plot under increasing current settings from 10 to 20. All error bars represent the standard deviation, where N = 3. FIG. 1F shows pictures of carbon paper before (upper) and during (lower) FJH. FIG.1G shows real-time current and temperature with a current setting of 15 for 150 s.

[0055] FIG.2 shows schematic of a process flow of the Li separation from spodumene by an alternative FJH method in which the naturally occurring α-spodumene converts to the more chemically active β-spodumene, after which the β-spodumene is leached with a diluted acid to achieve Li recovery.

[0056] FIGS. 3A-3D show phase transformation of spodumene. FIG. 3A shows an SEM image of ground spodumene powder sieved by a 53 µm mesh with an average particle size of 28.59 µm. The inset image is the raw α-spodumene sample as received. FIG. 3B shows the size distribution of sieved and ground spodumene particles. FIGS.3C-3D show XRD pattern and Raman spectra, respectively, of the spodumene before and after phase transformation, where the α-phase is present before heating and the β-phase is present after FJH at 1150 ºC.

[0057] FIGS. 4A-4B show Li extraction from the leached spodumene before and after FJH. FIG.4A shows ICP-MS results of the percentage of Li, Si, and Al before and after FJH. FIG. 4B shows purity and yield of Li from the leached spodumene before and after FJH.

[0058] FIGS.5A-5F show separation and recovery of Li from spodumene by FJH-Cl2. FIG.Attorney Docket No.: 072174-07101 5A shows the ICP-MS results of the raw spodumene showing the Li concentration related to the Si and Al. FIG. 5B shows thermodynamic analysis of the chlorination reaction of metal oxides. FIG.5C shows pictures of quartz tube containing spodumene before (upper) and after (lower) FJH-Cl2 when the LiCl (white volatile) has condensed inside the quartz tube. FIG.5D shows XPS spectra of spodumene before and residue after FJH-Cl2. FIG. 5E shows the composition of Li, Si, and Al in raw spodumene, and the volatile phase after FJH-Cl2 above the boiling point of LiCl, are shown for each of the three current settings. FIG.5F shows the purity and yield of LiCl after FJH-Cl2 of spodumene at current settings of 15, 18, and 20 for 30 s each. All error bars in (a), (e), and (f) represent the standard deviation, where N = 3.

[0059] FIGS. 6A-6F show DFT results for the delithiation energy of α-phase and β-phase spodumene. FIGS.6A-6B show top-view ball and stick model of α-phase spodumene before and after, respectively, extracting 100% of Li. FIG. 6C shows formation energy (Gibbs free energy) of delithiated α-phase spodumene at various temperatures and pressures. FIGS. 6D- 6E show top-view ball and stick model of β-phase spodumene before and after, respectively, extracting 100% of Li. FIG.6F shows formation energy of delithiated β-phase spodumene at various temperatures and pressures.

[0060] FIGS 7A-7D show a life cycle assessment (LCA) and techno-economic analysis (TEA) results for Li separation by H2SO4 roasting vs. FJH-Cl2 with (w / ) or without (w / o) intercontinental transportation (transp.). FIGS. 7A-7C show probability histograms for, respectively, the energy consumption in MJ, the global warming potential (GWP) in kg CO2, and the processing cost in US dollars necessary to produce 1 tonne of Li. FIG. 7D shows a radar plot simultaneously comparing the five key variables associated with the FJH-Cl2and industrial H2SO4 roasting processes to produce equal quantities of Li. DETAILED DESCRIPTION

[0061] The present invention relates to systems and methods for extraction of lithium fromAttorney Docket No.: 072174-07101 spodumene, and more particularly, systems and methods systems and methods for extraction of lithium from spodumene by Joule heating or electrothermal chlorination (which is Joule heating in the presence of a chlorinating source).

[0062] Previous work has shown that flash Joule heating (FJH), is an ultrafast, controllable, and energy-efficient method for processing. [Luong 2020; Deng II 2022; Chen 2012]. FJH is an ultrafast, controllable, and energy-efficient method that has been used for materials synthesis [Yao 2018; Zheng 2023; Chen 2016], waste upcycling [Cheng 2024; Wyss 2023; Dong 2023], and recovery of metals [Chen 2023; Deng 2022].

[0063] It has been discovered that FJH allows spodumene to be converted from α-phase to β- phase in seconds, and LiCl separation can ensue using only a dilute acid such as 1 M HCl. FIG.2. Such methods require the use of diluted acid.

[0064] Combining FJH with a gas chlorination process (FJH-Cl2) provides an alternative method of Li separation. FIG. 1C. When chlorine gas (Cl2) enters the chamber and is flash Joule heated in < 1 s, Li from the spodumene reacts with the Cl2to form volatile LiCl that distills from the unreacted silicon and aluminum oxides. FIG. 1D shows the generated LiCl evaporates and condenses on the inside of the quartz tube while the unreacted silicon and aluminum oxide residues remain on the carbon paper.

[0065] Such FJH-Cl2 processes can separate Li with high purity (>90%) and high yield (>90%) from spodumene. Unlike other techniques, electrothermal chlorination (FJH-Cl2) requires no solid or liquid chemical additives for Li separation, and the process only requires a water wash post-flash to achieve high purity and yield. Note that the gaseous Cl2 could be replaced by a solid or liquid source of chlorine atoms such as sodium chloride or organochloride like poly(vinyl chloride) (PVC), poly(vinylidene dichloride) (PVDC), or chlorinated poly(vinyl chloride) (CPVC or “Plumber’s Pipe”), and these polymers can be used in their waste form. Such FJH processes can be performed by adaption of the methods set forth in the Tour ‘707Attorney Docket No.: 072174-07101 PCT Application and the Tour ‘642 Patent Application. FJH-Cl2 processes reduce the ore processing time to seconds instead of the days needed in H2SO4roasting, and 12 to 18 months needed when processing Li brines by evaporation. FIG.1B.

[0066] Features for Li separation from spodumene can include:

[0067] The electrothermal chlorination (FJH-Cl2) process can be applied to extract and separate Li from spodumene. Feedstock can also extend to any lithium- containing mineral, like petalite, lepidolite, amblygonite, etc., or waste, such as electronic waste (e-waste) and spent batteries.

[0068] The feedstock, spodumene, can be directly converted from the naturally occurring α-phase to the more chemically active β-phase within 1-minute Joule heating. Lithium can be more easily extracted from the β-phase spodumene with 1 M dilute HCl. The amount of acid used depends on the mass of the spodumene sample.

[0069] Using the electrothermal chlorination (FJH-Cl2) process, Li separation can be achieved without the use of acids.When the chlorine gas (Cl2) is in contact withthe spodumene, the lithium chloride (LiCl) volatilescan be obtained on thecollection device, and the sample can be washed out with water or just scraped out to achieve the recovery and separation of Li. FJH Apparatuses and Processes

[0070] Such FJH processes of the present invention can be performed by adaption of the apparatuses and processes set forth in the Tour ‘707 PCT Application and the Tour ‘642 Patent Application. For example, a commercial arc welder with a maximum power output of 5.8 kW can power the laboratory-scale system, providing a rapid and stable electrical heat source for the reaction. The first advantage of this setup is temperature controllability, achieved by adjusting the current setting on the arc welder dial. See FIG. 1E (with the current setting inAttorney Docket No.: 072174-07101 arbitrary units on the dial and approximately but linearly modulating the current setting in the arc welder). The temperature profile of the unloaded carbon paper platform was measured using an infrared thermometer, where the temperature was ~1150 °C at a current output setting of 10, and ~1630 ºC at a current setting of 20.

[0071] Secondly, there is temperature uniformity. The surface of the heated carbon paper displays a uniform orange-red color, confirming a constant temperature induced by FJH across the carbon paper as verified with an infrared thermometer. FIG. 1F (showing pictures 151- 152, respectively of carbon paper before and during FJH.

[0072] Thirdly, there is temperature stability. When the current setting is 15, the voltage remained stable at 14 V, while the current output is 15 ± 5 A due to the high-frequency switching of the arc welder. The surface temperature of the carbon paper remains at 1420 ºC for the duration of the reaction. FIG. 1G (plots 161-162 showing real-time current and temperature with a current setting of 15 for 150 s and further showing temperature rise to >1380 °C in <1 s). Benefiting from resistive heating, the carbon paper system exhibits a rapid heating and cooling rate when using an arc welder as the power source. With the current setting at 18, the heating rate reached 1600 °C / s, while the cooling rate was 450 °C.

[0073] In an embodiment of the present invention, the Joule heating system included a power source, graphite rod, graphite block, and carbon paper. The power source utilized in this embodiment was a commercial arc welder, connected to the carbon paper via graphite rods and graphite blocks. A spodumene sample (50 mg) was spread evenly on the surface of carbon paper in a quartz tube and sealed at the ends of the tube with electrodes, an inlet chlorine gas line, and an outlet volatile gas line for unreacted chlorine. The quartz tube was conventionally 2.54 cm in interior diameter and 20 cm long. The size of carbon paper was generally 2 x 6 cm, and the resistance is 0.8-1.0 Ω. Argon gas (Airgas, 99.99%) was initially introduced into the chamber to purge the system atmosphere combined with a pumping system, and then chlorineAttorney Docket No.: 072174-07101 gas (Millipore Sigma, 99.5%) was introduced into the reaction system. To eliminate the need to keep the Cl₂ cylinder valve open continuously, a reservoir was positioned between the Cl2cylinder and the gas pipeline, thereby reducing the risk of Cl2 release in case of system failure. A CGA-180 fitting with a PTFE O-ring ensured a secure seal. Stainless steel was used for both tubing and fittings. To neutralize any unreacted Cl₂, the outlet was connected to two absorption traps: one containing solid sodium hydroxide (NaOH) and the other containing an aqueous NaOH solution. The entire system is in a well-ventilated hood. Note that when industrialized, the unreacted Cl2 could be easily recovered and reused. [O’Brien 2005; Lokhandwala 1999]. Conversion Of α-Spodumene To β-Spodumene

[0074] Spodumene exists in different crystalline phases, typically in its natural α-phase or rock form. See FIG.3A (inset image 301 is the raw α-spodumene sample as received.). Before the FJH process, the spodumene rock was ground into micron-sized powder using a mortar and pestle and then sieved through successive meshes with pore sizes of 1000 µm, 200 µm, and 53 µm to obtain particles of corresponding sizes, which were classified here as large, medium, and small particles. Scanning electron microscopy (SEM) images show these particles as uniformly sized but irregularly shaped. FIG. 3A. The particle size distribution of the three sieved spodumene samples is measured by combining laser diffraction / scattering and dynamic image analysis. The particles sieved through a 53 µm mesh have an average size of 28.59 µm, with D50 and D90 values of 22.42 µm and 62.36 µm, respectively. FIG. 3B (plots 311-312 for counts and percentage, respectively). This means that 50% of the sample has a size of 22.42 µm or smaller, and 90% of the sample has a particle size of 62.36 µm or smaller.

[0075] When spodumene particles are subjected to FJH, the α-phase converts to the β-phase. The X-ray diffraction (XRD) pattern shows that the two phases are clearly different. FIG.3C (plots 321-322 for α-spodumene and β-spodumene, respectively). [Abdullah 2019]. However, the complete phase transformation varies with different particle sizes due to inefficient heatAttorney Docket No.: 072174-07101 transfer with large particles. When small-sized particles (average size at 28.59 µm) were subjected to 30 s of FJH at 1150 °C, only the β-phase signal was observed after the treatment. FIG. 3C. Raman spectroscopy further illustrated that the untreated α-phase exhibited typical Raman peaks ~370 cm-1and 700 cm-1. The small particles treated by FJH only show the characteristic Raman peak of the β-phase at ~500 cm-1. FIG. 3D (plots 331-332 for α-spodumene and β-spodumene, respectively). [Buzatu 2010; Pommier 2003].

[0076] However, using FJH and 1 M HCl treatment (FIG.2) has a greater effect on improving the LiCl yield than the purity. When the spodumene average size is 28.59 µm, the yield of Li was increased from 56.6% before FJH to 90.2% after FJH with 1 M HCl extraction. FIG.4A (bars 401-403 for Al, Si, and Li, respectively, and with the digestion done with a mixture of aqua regia and HF, and the other samples were leached with 1 M HCl at 90 ºC); FIG.4B (with plots 411-412 for purity and yield). FJH-Cl2Of Spodumene

[0077] FJH can afford the formation of β-spodumene in seconds, which is necessary to increase the efficiency of Li extraction. Utilizing the methods shown in FIG.2 does not eliminate the use of acid, moreover, while purity of Li was improved by such methods, limitations in the purity of Li can remain.

[0078] Inductively coupled plasma mass spectrometry (ICP-MS) results showed that the main elements in the spodumene rock were Li, Al, and Si, with Li accounting for 4.8% of the total content of these three elements. FIG.5A. This is consistent with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and XPS results.

[0079] A thermodynamic analysis was conducted for chlorinating silicon oxide (SiO2), aluminum oxide (Al2O3), and lithium oxide (Li2O). According to the Gibbs free energy change (ΔG) vs. temperature, only Li2O is chlorinated below 2000 ºC, while chlorination does not occur for SiO2 and Al2O3 within that temperature range. FIG.5B (plots 511-513 for Si, Al, andAttorney Docket No.: 072174-07101 Li, respectively, with only the chlorination of Li2O feasible above 514 ºC when the ΔG is negative (below the dotted line 514); TABLE I. TABLE I Chlorination temperature of Li, Si, and Al oxides and their solubility

[0080] ΔG is negative for Li2O when the temperature exceeds 514 ºC, indicating that Li in spodumene can be chlorinated at ~514 ºC. However, when the chlorination reaction occurs between 514 °C and the boiling point of LiCl (1382 °C), leaching the formed LiCl with water resulted in low purity and yield of Li due to the interference of Si and Al impurities in the sample. However, when the control temperature was above the boiling point of LiCl, and below 2000 ºC, LiCl can be cleanly volatilized and separated from spodumene. FIG.1C.

[0081] When the arc welder settings are 15, 18, and 20, the corresponding temperatures were 1420 ºC, 1550 ºC, and 1630 ºC, respectively. After 30 s of chlorinating spodumene, volatile LiCl deposited on the inner surface of the quartz tube. FIG. 5C (shows pictures 521-522 of quartz tube containing spodumene, respectively, before and after FJH-Cl2when the LiCl (white volatile) has condensed inside the quartz tube). SEM-EDX characterization results indicated that the primary element in the volatile fraction was Cl, with trace amounts of Si and Al, and with Li being too light to be detected. XPS results also showed that the main elements in the volatile fraction are Cl, O, and Li.

[0082] After the chlorination reaction, a significant amount of residue remained on the carbon paper, SEM-EDX, XPS, and XRD results revealed that the main elements in the residue were Si, Al, O, and Cl.

[0083] By comparing the XPS fine spectra of Li in the original spodumene sample with theAttorney Docket No.: 072174-07101 residue, there is no detectable Li signal in the residue after FJH-Cl2. FIG.5D (plots 531-532 for spodumene and residue, respectively; the Li 1s signal is only detected before FJH-Cl2). This result indicated that the FJH-Cl2 reaction can selectively and efficiently separate Li as LiCl directly from raw spodumene. The residue can be easily removed without surface degradation.

[0084] High-temperature vapor-phase reactions can inevitably introduce SiO2and Al2O3into the volatile phase via physical mass transport processes during the rapid LiCl volatilization; in an industrialized process, further fractionation plates can be desirable. Interestingly, ICP-MS results showed that purity can be enhanced when the volatile obtained from the chlorination reaction is rinsed with water. FIG.5E (composition percentages 541-543 are for Al, Si, and LI, respectively). LiCl is water-soluble while SiO2and Al2O3are not (TABLE I), so the water- wash acts as an additional purification step while extracting only the condensed LiCl from the quartz tube. As a result, the purity of Li obtained from FJH-Cl2can reach 97% with an average purity of 94%. FIG.5E.

[0085] Furthermore, the yield of LiCl was related to the particle size of the sample and the chlorination temperature. As the particle size of the spodumene decreased, the yield of Li increased. When the particle size of spodumene was ~459 µm and the current dial was set to 18 (1550 ºC), the yield of Li obtained from 30 s FJH-Cl2was only 17%. With a particle size of ~143 µm, the yield of Li was slightly increased to 54%. However, when the particle size was reduced to ~28.3 µm, the yield of Li reached 90%. The short reaction time allows smaller particles to provide a larger contact area with the gas, thereby significantly enhancing the efficiency and rate of metal extraction. FIG.5F (with plots 551-552 for purity and yield).

[0086] Temperature influences both the thermodynamic driving force and the kinetic rate of reaction. When the particle size is ~28.3 µm and the arc welder setting was 15 (1420 ºC), the yield was still only 69.3%. FIG.5F. However, when the current dial was set to 18 (1550 ºC), extracted LiCl with a maximum purity of 97% and an average purity of 94%, as well as aAttorney Docket No.: 072174-07101 maximum yield of 94% and an average yield of 90%, can be obtained. FIG. 5F. Further increasing the temperature with a dial setting at 20 introduced more Si and Al impurities into the volatile phase (FIG. 5F), leading to a slight decrease in purity. Moreover, higher temperatures inevitably result in greater energy consumption when the yield is close to that at a dial setting of 18.

[0087] Hence, when the temperature was set to 1550 °C, the formation of LiCl occurred at ~514 °C and its distillation at ~1382 °C, which are favored both thermodynamically and kinetically. It is a common observation that one needs to exceed the boiling point of a material to increase its distillation rate, and in this case 168 °C since the temperatures are so high relative to the surroundings.

[0088] Other sources of spodumene ore were used to ensure that the process worked equally well regardless of the region from which the sample was mined. [US Geological 2024]. Here, sand-like spodumene from Australia was used for Li extraction by FJH-Cl2. When the Australian spodumene was ground to ~47 µm particle size and underwent FJH-Cl2, 90% purity and 89% yield of Li can be achieved at a current setting of 18. Process Mechanisms

[0089] To understand why the chlorination method can so efficiently and quickly separate Li from spodumene, density functional theory (DFT) calculations were employed to further understand the mechanism of this process. The energy required to separate 50% and 100% of the Li from both α-spodumene and β-spodumene between 1600 K and 2000 K and at 1, 6, and 11 atm was calculated. FIGS.6A-6F.

[0090] Generally, natural spodumene is in the α-phase, which is monoclinic (FIG. 6A, with atoms 601-604 for O atoms, Al atoms, Si atoms, and Li atoms, respectively), after extracting all the Li, the structure is different from the α-phase spodumene but still stable (FIG. 4B). When increasing the temperature from 1600 K to 2000 K and decreasing the pressure from 11Attorney Docket No.: 072174-07101 atm to 1 atm, the chlorination for extracting Li from α-phase spodumene requires less energy. FIG.6C (with plots 621-623 for 1 atm, 6 atm, and 11 atm, respectively).

[0091] During the FJH process, the spodumene readily converts from the monoclinic α-phase to the tetragonal β-phase (FIG.6D, with atoms 631-634 for O atoms, Al atoms, Si atoms, and Li atoms, respectively). After extracting the Li from β-phase spodumene, the structure frame (FIG.6E) is totally different from that of α-phase spodumene.

[0092] Of import, delithiation from the β-phase spodumene requires less energy under the same temperature and pressure than the α-phase. Full delithiation energy from β-phase spodumene is by 0.23 eV / Li lower than that of α-phase spodumene (FIG.6F, with plots 651-653 for 1 atm, 6 atm, and 11 atm, respectively), and by 0.12 eV / Li lower than α-phase spodumene for half delithiation.

[0093] These results showed that delithiation of β-phase spodumene was significantly more exothermic and therefore more favorable than α-phase spodumene. It is believed that during the FJH-Cl2process, spodumene first converts from the α-phase to the β-phase before reacting with Cl2allowing for a lower-energy Li separation process. LCA, TEA, and Environmental Impacts

[0094] A Monte Carlo life cycle assessment (LCA) and techno-economic analysis (TEA) were employed. The primary environmental and economic factors considered were energy consumption, greenhouse gas emissions of CO2listed as global warming potential (GWP), water consumption, and reagent use including, acid, Cl2, etc., and processing cost. FIGS.7A- 7D (with the higher the probability and narrower the plotted histogram, the more accurate the prediction). These factors were chosen since they contribute the most to the operating expenses (OpEx) materials costs, consumption, and produced waste. Processing 1 tonne of high-grade spodumene ore would produce 44 to 48 kg of Li for both methods because similar yields were achieved in both FJH-Cl2and H2SO4roasting processes.Attorney Docket No.: 072174-07101

[0095] The LCA showed that FJH-Cl2 can reduce the process energy consumption by 77% from 15,900 MJ to 3700 MJ. FIG.7A (energy consumption with bars 701-702 for FJH-Cl2and H2SO4 roast, respectively). Water consumption was reduced by 67% from 373,000 kg to 125,000 kg if using the same relative amount needed for this laboratory process, or 100% reduction of water if the equipment is industrialized at a longer evaporation distance, thereby inhibiting physical transport of the silicon or aluminum oxides with sufficient theoretical plates. Reagent consumption was reduced by 93% and acid consumption was also 100% eliminated.

[0096] However, these do not fully capture the improvement to the H2SO4 roasting method, as intercontinental transportation of spodumene ore for processing significantly increases OpEx, which FJH-Cl2can eliminate. When accounting for intercontinental transportation in the H2SO4roasting process, FJH-Cl2 can reduce the GWP by up to 82% from 30,800 kg CO2 to 5,600 kg CO2(FIG.7B (global warming potential) with bars 711-713 for FJH-Cl2, H2SO4roast (without transportation), and H2SO4 roast (with transportation), respectively), and the TEA shows a reduction in OpEx of up to 81% from $4,900 to $950 tonne-1. FIG.7C (processing cost with bars 721-723 for FJH-Cl2, H2SO4roast (without transportation), and H2SO4roast (with transportation), respectively); FIG. 7D (areas 721-723 for FJH-Cl2, H2SO4 roast (without transportation), and H2SO4roast (with transportation), respectively). Applications and Uses

[0097] It has been discovered that spodumene can be converted from the α-phase to the β- phase with only 30 s of FJH. An inexpensive arc welder can be used on a laboratory scale to facilitate this process. A FJH-Cl2 method was shown to separate Li with maximum purity of 97% and an average purity of 94%, as well as a maximum yield of 94% and an average yield of 90%. DFT calculations indicate that extracting Li from β-phase spodumene requires less energy, suggesting that spodumene converts first from the α-phase to the β-phase during the chlorination. LCA and TEA confirmed that the acid-free FJH-Cl2method can greatly reduceAttorney Docket No.: 072174-07101 the total energy consumption, capital and operating costs, water consumption and emissions compared to the industrial standard, H2SO4roasting. Capitalizing upon the differences in ∆Gform of the LiCl vs. silicon and aluminum chlorides, these results reveal the FJH-Cl2 method as an efficient and environmentally friendly process for Li separation from ores.

[0098] The processes of the present invention can extend into the separation of Li from spent batteries and will provide for the extraction of critical metals from other minerals. This rapid Li separation method permits local Li assets to be developed, lessening transportation and processing costs for renewable energy transitions.

[0099] Flash Joule heated spodumene can improve current Li extraction technologies by reducing energy consumption, eliminating harsh acids and bases, and reducing the duration of the reaction. The separated lithium can be used in battery production to better meet the demands of clean energy technology production while reducing greenhouse gas emissions, chemicals used, and power consumption. This technology can be applied to other lithium ores, or separation of any selected metals from their ores.

[0100] The systems and methods of the present invention provide a faster, more energy efficient, and cheaper method of lithium extraction from spodumene. While Joule heating has been previously demonstrated to produce graphene, it has not until now been used to separate Li from ores such as spodumene, particularly when used in conjunction with the chlorination method. The current industry method for Li extraction from spodumene involves a rotary kiln to convert the naturally occurring α phase to the more chemically active β-phase at 1,100 °C for 30 minutes, before going through a calciner to react β-spodumene with sulfuric acid at 250-300 °C for 10–60 minutes. This involves additional acid leaching and purification steps and produces slag. This electrothermal chlorination method eliminates all those stepsand condenses it into a single-step process, converting the α-spodumene to β-spodumene,reacting with the Cl2 gas, and separating from the residue, completed with 30-60s of reactionAttorney Docket No.: 072174-07101 time.

[0101] That the FJH and FJH-Cl2processes work better for the smaller particle sizes can be particularly advantageous since traditional calcination and roasting kilns have materials handling problems with the smaller particles, and they are normally rejected as part of the tailings. These smaller particles can come from traditional spodumene concentrator plants. These formerly rejected particles can constitute even 20% of the ore by weight. Therefore, typically rejected material could afford a useful lithium asset using the processes described herein.

[0102] While embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described and the examples provided herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. The scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.

[0103] The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated herein by reference in their entirety, to the extent that they provide exemplary, procedural, or other details supplementary to those set forth herein.

[0104] Amounts and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a numerical range of approximately 1 to approximately 4.5 should be interpreted to include not only the explicitly recited limits of 1 to approximately 4.5, but also to include individualAttorney Docket No.: 072174-07101 numerals such as 2, 3, 4, and sub-ranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges reciting only one numerical value, such as “less than approximately 4.5,” which should be interpreted to include all of the above-recited values and ranges. Further, such an interpretation should apply regardless of the breadth of the range or the characteristic being described.

[0105] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the presently disclosed subject matter belongs. Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the presently disclosed subject matter, representative methods, devices, and materials are now described.

[0106] Following long-standing patent law convention, the terms “a” and “an” mean “one or more” when used in this application, including the claims.

[0107] Unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter.

[0108] As used herein, the term “about” and “substantially” when referring to a value or to an amount of mass, weight, time, volume, concentration or percentage is meant to encompass variations of in some embodiments ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, and in some embodiments ±0.1% from the specified amount, as such variations are appropriate to perform the disclosed method.

[0109] As used herein, the term “substantially perpendicular” and “substantially parallel” isAttorney Docket No.: 072174-07101 meant to encompass variations of in some embodiments within ±10° of the perpendicular and parallel directions, respectively, in some embodiments within ±5° of the perpendicular and parallel directions, respectively, in some embodiments within ±1° of the perpendicular and parallel directions, respectively, and in some embodiments within ±0.5° of the perpendicular and parallel directions, respectively.

[0110] As used herein, the term “and / or” when used in the context of a listing of entities, refers to the entities being present singly or in combination. Thus, for example, the phrase “A, B, C, and / or D” includes A, B, C, and D individually, but also includes any and all combinations and subcombinations of A, B, C, and D. REFERENCES

[0111] United States Patent Appl. Publ. No.2021 / 0206642A1, to James M. Tour et al., entitled “Flash Joule Heating Synthesis Method And Compositions Thereof,” filed March 2, 2021 (“Tour ‘642 Patent Application”).

[0112] PCT Patent Appl. Serial No. PCT / US2023 / 76707, to James M. Tour et al., entitled “Electrothermal Chlorination And Carbochlorination Systems and Methods Of Selective Metal Recover,” filed October 12, 2023 (“Tour ‘707 PCT Application”).

[0113] AACE International Recommended Practice No.56R-08, “Cost Estimate Classification System – As Applied in Engineering, Procurement, and Construction for The Building and General Construction Industries,” AACE International, 2020 (“AACE 2020”).

[0114] Abdullah, A. A., et al., “Phase transformation mechanism of spodumene during its calcination,” Miner. Eng., 2019, 140, 105883 (“Abdullah 2019”).

[0115] Alessia, A., et al., “Challenges for sustainable lithium supply: A critical review,” J. Clean. Prod., 2021, 300, 126954 (“Alessia 2021”).

[0116] Anderson, A., et al., New Directions in Mineral Processing, Extractive Metallurgy, Recycling and Waste Minimization An EPD Symposium in Honor of Patrick R. Taylor, 2023Attorney Docket No.: 072174-07101 (“Anderson 2023”).

[0117] Barbosa, L. I., et al., “Extraction of lithium from β-spodumene using chlorination roasting with calcium chloride,” Thermochim. Acta, 2015, 605, 63-67 (“Barbosa 2015”).

[0118] Barbosa, L. I., et al., “Lithium extraction from β-spodumene through chlorination with chlorine gas,” Miner. Eng., 2014, 56, 29-34 (“Barbosa 2014”).

[0119] Battistel, A., et al., “Electrochemical Methods for Lithium Recovery: A Comprehensive and Critical Review,” Adv Mater, 2020, 32, e1905440 (“Battistel 2020”).

[0120] Blochl, P. E., “Projector augmented-wave method,” Phys. Rev. B, 1994, 50, 17953- 17979 (“Blochl 1994”).

[0121] Buzatu, A., et al., “The Raman study of single-chain silicates,” Analele Stiint. ale Univ., 2010, 4, 107-125 (“Buzatu 2010”).

[0122] Chen, W. Y., et al., “Battery metal recycling by flash Joule heating,” Sci. Adv., 2023, 9, eadh5131 (“Chen 2023”).

[0123] Chen, W., et al., “Millisecond conversion of metastable 2D materials by flash Joule heating,” ACS Nano, 2021, 15, 1282–1290 (“Chen 2021”).

[0124] Chen, Y., et al., “Ultra-fast self-assembly and stabilization of reactive nanoparticles in reduced graphene oxide films,” Nat. Commun., 2016, 7, 12332 (“Chen 2016”).

[0125] Chen, Y., et al., “Preparation of lithium carbonate from spodumene by a sodium carbonate autoclave process,” Hydrometallurgy, 2011, 109, 43-46 (“Chen 2011”).

[0126] Cheng, Y., et al., “Flash upcycling of waste glass fibre-reinforced plastics to silicon carbide,” Nat. Suatain., 2024, 7, 452-462 (“Cheng 2024”).

[0127] Deng, B., et al., “Flash separation of metals by electrothermal chlorination,” Nat. Chem. Eng., 2024, 1, 627–637 (“Deng 2024”).

[0128] Deng, B., et al., “Rare earth elements from waste,” Sci. Adv., 2022, 8, eabm3132 (“Deng I 2022”).Attorney Docket No.: 072174-07101

[0129] Deng, B., et al., “Phase controlled synthesis of transition metal carbide nanocrystals by ultrafast flash Joule heating” Nat. Commun., 2022, 13, 262 (“Deng II 2022”).

[0130] Dessemond, C., et al., “Spodumene: The lithium market, resources and processes,” Minerals, 2019, 9, 1-17 (“Dessemond 2019”).

[0131] Dong, Q., et al., “Depolymerization of plastics by means of electrified spatiotemporal heating,” Nature, 2023, 616, 488-494 (“Dong 2023”).

[0132] Dudarev, S. L., et al., “Electron-energy-loss spectra and the structural stability of nickel oxide: An LSDA+U study,” Phys. Rev. B, 1998, 57, 1505-1509 (“Dudarev 1998”).

[0133] Eddy, L., et al., “Kilogram flash Joule heating synthesis with an arc welder,” ACS Nano, 2024, 18, 34207–34218 (“Eddy 2024”).

[0134] Flexer, V., et al., “Lithium recovery from brines: A vital raw material for green energies with a potential environmental impact in its mining and processing,” Sci. Total Environ., 2018, 639, 1188-1204 (“Flexer 2018”).

[0135] Fosu, A. Y., et al., “Literature review and thermodynamic modelling of roasting processes for lithium extraction from spodumene,” Metals, 2020, 10, 1312 (“Fosu 2020”).

[0136] Gemological Institute of America Inc., Kunzite Description, 2024 (“Gia 2024”).

[0137] Graedel, T. E., et al., “Criticality of metals and metalloids,” PNAS, 2015, 112, 4257- 4262 (“Graedel 2015”).

[0138] Guo, H., et al., “Investigation of enhanced leaching of lithium from α-spodumene using hydrofluoric and sulfuric acid,” Minerals, 2017, 7, 205 (“Guo 2017”).

[0139] Kresse, G., et al., “Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set,” Phys. Rev. B, 1996, 54, 11169-11186 (“Kresse 1996”).

[0140] Kuang, G., et al., “Extraction of lithium from β-spodumene using sodium sulfate solution,” Hydrometallurgy, 2018, 177, 49-56 (“Kuang 2018”).

[0141] Kundu, T., et al., “Recovery of Lithium from Spodumene-Bearing Pegmatites: AAttorney Docket No.: 072174-07101 Comprehensive Review on Geological Reserves, Beneficiation, and Extraction,” Powder Technology, 2023, 415, 118142 (“Kundu 2023”).

[0142] Lajoie-Leroux, F., et al., “Impact of the impurities on lithium extraction from β- spodumene in the sulfuric acid process,” Miner. Eng., 2018, 129, 1-8 (“Lajoie-Leroux 2018”).

[0143] Li, N., et al., “Aqueous leaching of lithium from simulated pyrometallurgical slag by sodium sulfate roasting,” RSC Adv., 2019, 9, 23908–23915 (“Li 2019”).

[0144] Li, Z., et al., “Lithium extraction from brine through a decoupled and membrane-free electrochemical cell design,” Science, 2024, 385, 1438–1444 (“Li 2024”).

[0145] Lockwood, D. J., “Rayleigh and Mie Scattering,” Encyclopedia of Color Science and Technology, Shamey, R. (eds) Springer, Berlin, Heidelberg, 2019 (“Lockwood 2019”).

[0146] Lokhandwala, K. A., et al., “Membrane Process To Recover Chlorine from Chloralkali Plant Tail Gas,” Ind. Eng. Chem. Res., 1999, 38, 3606-3613 (“Lokhandwala 1999”).

[0147] Luong, D. X., et al., “Gram-scale bottom-up flash graphene synthesis,” Nature, 2020, 577, 647–651 (“Luong 2020”).

[0148] Lv, W., et al., “A critical review and analysis on the recycling of spent lithium-ion batteries,” ACS Sustain. Chem. Eng., 2018, 6, 1504–1521 (“Lv 2018”).

[0149] Meshram, P., et al., “Extraction of lithium from primary and secondary sources by pre- treatment, leaching and separation: A comprehensive review,” Hydrometallurgy, 2014, 150, 192-208 (“Meshram 2014”).

[0150] Moats, M.S., et al., “Nickel and cobalt production,” In Treatise on Process Metallurgy: Industrial Processes, 2014, 3, 625–669 (“Moats 2014”).

[0151] Monkhorst, H. J., et al., “Special points for Brillouin-zone integrations,” Phys. Rev. B, 1976, 13, 5188-5192 (“Monkhorst 1976”).

[0152] O’Brien, T. F., et al., “Handbook of Chlor-Alkali Technology,” Springer US, Boston, 2005 (“O’Brien 2005”).Attorney Docket No.: 072174-07101

[0153] Olivetti, E. A., et al., “Lithium-ion battery supply chain considerations: Analysis of potential bottlenecks in critical metals,” Joule, 2017, 1, 229-243 (“Olivetti 2017”).

[0154] Qiu, S., et al., “Kinetics and Mechanism of Lithium Extraction from α-Spodumene in Potassium Hydroxide Solution,” Ind. Eng. Chem. Res., 2022, 61, 15103–15113 (“Qui 2022”).

[0155] Pommier, C. J. S., et al., “Raman spectroscopic study of spodumene (LiAlSi2O6) through the pressure‐induced phase change from C2 / c to P21 / c,” J. Raman Spectrosc., 2003, 34, 769-775 (“Pommier 2003”).

[0156] Perdew, J. P., et al., “Generalized gradient approximation made simple,” Phys. Rev. Lett., 1996, 77, 3865 (“Perdew 1996”).

[0157] Reck, B. K., et al., “Challenges in metal recycling,” Science, 2012, 337, 690-695 (“Reck 2012”).

[0158] Reuter, K., et al., “Composition, structure, and stability of RuO2(110) as a function of oxygen pressure,” Phys. Rev. B, 2002, 65, 035406 (“Reuter 2002”).

[0159] Rioyo, J., et al., “Lithium Extraction from Spodumene by the Traditional Sulfuric Acid Process: A Review,” Mineral Processing and Extractive Metallurgy Review, 2022, 43, 97–106 (“Rioyo 2022”).

[0160] Rosales, G. D., et al., “Efficient extraction of lithium from β-spodumene by direct roasting with NaF and leaching,” Chem. Eng. Res. Des., 2019, 150, 320-326 (“Rosales 2019”).

[0161] Rosales, G., et al., “Novel process for the extraction of lithium from β-spodumene by leaching with HF,” Hydrometallurgy, 2014, 147-148, 1-6 (“Rosales 2014”)

[0162] Salakjani, N. K., “Extraction of lithium from spodumene,” thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in the Department of Engineering and Energy; College of Science, Health, Engineering and Education; Murdoch University, September 2019 (“Salakjani 2019”).

[0163] dos Santos, L. L., et al., “Beta-spodumene: Na2CO3:NaCl system calcination: A kineticAttorney Docket No.: 072174-07101 study of the conversion to lithium salt,” Chem. Eng. Res. Des., 2019, 147, 338-345 (“dos Santos 2019”).

[0164] Stull, D. R., et al., “JANAF Thermochemical Tables, 2nd ed. ~U.S. National Bureau of Standards, Washington, DC, 1971 (“Stull 1971”).

[0165] Swain, B., “Recovery and Recycling of Lithium: A Review,” Separation and Purification Technology, 2017, 172, 388–403 (“Swain 2017”).

[0166] Tadesse, B., et al., “The beneficiation of lithium minerals from hard rock ores: A review,” Miner. Eng., 2019, 131, 170-184 (“Tadesse 2019”).

[0167] Trahey, L., et al., “Energy storage emerging: A perspective from the Joint Center for Energy Storage Research,” PNAS, 2020, 117, 12550-12557 (“Trahey 2020”).

[0168] Tran, M. K., et al., “Deep eutectic solvents for cathode recycling of Li-ion batteries,” Nat. Energy, 2019, 4, 339–345 (“Tran 2019”).

[0169] U.S. Geological Survey, Mineral Commodity Summaries 2024,” 2024, 1-212. (“US Geological 2024”).

[0170] Vera, M. L., et al., “Environmental impact of direct lithium extraction from brines,” Nat. Rev. Earth Env., 2023, 4, 149-165 (“Vera 2023”).

[0171] Wyss, K. M., et al., “Upcycling of waste plastic into hybrid carbon nanomaterials,” Adv. Mater., 2023, 35, e2209621 (“Wyss 2023”).

[0172] Xiao, J., et al., “Highly Efficient Selective Recovery of Lithium from Spent Lithium- Ion Batteries by Thermal Reduction with Cheap Ammonia Reagent,” Journal of Hazardous Materials, 2021, 418, 126319 (“Xiao 2021”).

[0173] Xie, R., et al., “The flotation behavior and adsorption mechanism of a new cationic collector on the separation of spodumene from feldspar and quartz,” Sep. Purif. Technol., 2021, 264, 118445 (“Xie I 2021”).

[0174] Xie, R., et al., “Flotation behavior and mechanism of α-bromododecanoic acid asAttorney Docket No.: 072174-07101 collector on the flotation separation of spodumene from feldspar and quartz,” J. Mol. Liq., 2021, 336, 116303 (“Xie II 2021”).

[0175] Xu, C., et al., “Future material demand for automotive lithium-based batteries,” Commun. Mater., 2020, 1, 99 (“Xu 2020”).

[0176] Yan, Q., et al., “Extraction of valuable metals from lepidolite,” Hydrometallurgy, 2012, 117, 116-118 (“Yan 2012”).

[0177] Yang, S., et al., “Lithium metal extraction from seawater,” Joule, 2018, 2, 1648-1651 (“Yang 2018”).

[0178] Yao, Y. G., et al., “Carbothermal shock synthesis of high-entropy-alloy nanoparticles,” Science, 2018, 359, 1489-1494 (“Yao 2018”).

[0179] Yong, M., et al., “Sustainable lithium extraction and magnesium hydroxide co- production from salt-lake brines,” Nat. Sustain., 2024, 7(12), 1662-1671 (“Yong 2024”).

[0180] Zhang, G., et al., “Spontaneous lithium extraction and enrichment from brine with net energy output driven by counter-ion gradients,” Nat Water, 2024, 2, 1091–1101 (“Zhang 2024”).

[0181] Zhang, H. R., et al., “Direct extraction of lithium from ores by electrochemical leaching,” Nat. Commun., 2024, 15, 5066 (“Zhang 2024”).

[0182] Zheng, X., et al., “Hydrogen-substituted graphdiyne-assisted ultrafast sparking synthesis of metastable nanomaterials,” Nat. Nanotechnol., 2023, 18, 153-159 (“Zheng 2023”).

[0183] Zhou, H., et al., “Selective and efficient extraction of lithium from spodumene via nitric acid pressure leaching,” Chem. Eng. Sci., 2024, 287, 119736 (“Zhou 2024”).

[0184] Zhu, G., et al., “Surface features and flotation behaviors of spodumene as influenced by acid and alkali treatments,” Appl. Surf. Sci., 2020, 507, 145058 (“Zhu 2020”).

Claims

Attorney Docket No.: 072174-07101 WHAT IS CLAIMED IS:

1. A method comprising (a) selecting a material or mixture comprising α-spodumene; and (b) Joule heating the material or mixture to convert the α-spodumene to β- spodumene.

2. The method of Claim 1 further comprising leaching the β-spodumene with an acid.

3. The method of Claim 2, wherein (a) the acid is a diluted acid ,and (b) the diluted acid has a molar concentration of at most 3 M.

4. The method of Claim 3, wherein the molar concentration of the diluted acid is at most 1 M.

5. The method of Claim 1, wherein the β-spodumene is stirred with an acid to obtain lithium salts dissolved in the acid.

6. The method of Claim 5, wherein the acid is HCl having a molar concentration of at most 1 M.

7. The method of Claim 5, wherein the acid is selected from the group consisting of hydrochloric acid, acetic acid, sulfuric acid, mineral acid, and organic acid.

8. The method of Claim 7, wherein the acid is diluted with water.Attorney Docket No.: 072174-07101 9. The method of any of Claims 1-8, wherein the Joule heating is flash Joule heating.

10. The method of any of Claims 1-9, wherein the Joule heating is performed at a Joule heating temperature of at least 1100 °C.

11. A method comprising (a) selecting a material or mixture comprising α-spodumene, β-spodumene, or a combination thereof; and (b) Joule heating the material or mixture in the presence of a chlorine source to afford a volatile lithium chloride species that separates by volatilization from solid residue.

12. The method of Claim 11, wherein the chlorine source is selected from the group consisting of chlorine gas, gas sources of chlorine atoms, solid sources of chlorine atoms, and liquid sources of chlorine atoms.

13. The method of Claim 11, wherein the chlorine source is chlorine gas.

14. The method of Claim 11, wherein the chlorine source is selected from the group consisting of sodium chloride, organochloride, poly(vinyl chloride) (PVC), poly(vinylidene dichloride) (PVDC), and chlorinated poly(vinyl chloride) (CPVC).

15. The method of any of Claims 11-14, wherein (a) the Joule heating of the material is performed in a reaction chamber; andAttorney Docket No.: 072174-07101 (b) the volatile lithium chloride species is separated by volatilization from the solid residue in the reaction chamber.

16. The method of any of Claims 11-15, wherein the solid residue comprises a solid residue material selected from the group consisting of SiO2,Al2O3, and a combination thereof.

17. The method of any of Claims 11-16, wherein the Joule heating is flash Joule heating.

18. The method of any of Claims 11-17, wherein the Joule heating is performed at a Joule heating temperature of at least 1550 °C.

19. The method of any of Claims 11-18 further comprising rinsing the volatile with water to separate the Li.

20. A system that performs the method selected from the group consisting of the method of Claims 1-19.

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